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1.  Autophagy-independent enhancing effects of Beclin 1 on cytotoxicity of ovarian cancer cells mediated by proteasome inhibitors 
BMC Cancer  2012;12:622.
Background
The ubiquitin-proteasome system and macroautophagy (hereafter referred to autophagy) are two complementary pathways for protein degradation. Emerging evidence suggests that proteasome inhibition might be a promising approach for tumor therapy. Accumulating data suggest that autophagy is activated as a compensatory mechanism upon proteasome activity is impaired.
Method
Autophagy activation was measured using acridine orange staining and LC3 transition. Cell viability and apoptosis were measured using MTT assay and flow cytometry, respectively. Beclin 1 expression vectors or shRNA against Beclin 1 (shBeclin 1) were transfected to investigate the role of Beclin 1 in autophagy activation and cytotoxicity of ovarian cancer cells induced by proteasome inhibitors.
Results
Proteasome inhibitors suppressed proliferation and induced autophagy in ovarian cancer cells. Neither phosphoinositide 3-kinase (PI3K) inhibitors nor shRNA against Beclin 1 could abolish the formation of acidic vacuoles and the processing of LC3 induced by proteasome inhibitors. Moreover, Beclin 1 overexpression enhanced anti-proliferative effects of proteasome inhibitors in ovarian cancer cells.
Conclusions
For the first time, the current study demonstrated that proteasome inhibitors induced PI3K and Beclin 1-independent autophagy in ovarian cancer cells. In addition, this study revealed autophagy-independent tumor suppressive effects of Beclin 1 in ovarian cancer cells.
doi:10.1186/1471-2407-12-622
PMCID: PMC3553022  PMID: 23270461
Proteasome inhibition; Beclin1; Ovarian cancer
2.  MicroRNA-196a promotes non-small cell lung cancer cell proliferation and invasion through targeting HOXA5 
BMC Cancer  2012;12:348.
Background
MicroRNAs (miRNAs) are short, non-coding RNAs (~22 nt) that play important roles in the pathogenesis of human diseases by negatively regulating gene expression. Although miR-196a has been implicated in several other cancers, its role in non-small cell lung cancer (NSCLC) is unknown. The aim of the present study was to examine the expression pattern of miR-196a in NSCLC and its clinical significance, as well as its biological role in tumor progression.
Methods
Expression of miR-196a was analyzed in 34 NSCLC tissues and five NSCLC cell lines by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The effect of DNA methylation on miR-196a expression was investigated by 5-aza-2-deoxy-cytidine treatment and bisulfite sequencing. The effect of miR-196a on proliferation was evaluated by MTT and colony formation assays, and cell migration and invasion were evaluated by transwell assays. Analysis of target protein expression was determined by western blotting. Luciferase reporter plasmids were constructed to confirm the action of miR-196a on downstream target genes, including HOXA5. Differences between the results were tested for significance using Student’s t-test (two-tailed).
Results
miR-196a was highly expressed both in NSCLC samples and cell lines compared with their corresponding normal counterparts, and the expression of miR-196a may be affected by DNA demethylation. Higher expression of miR-196a in NSCLC tissues was associated with a higher clinical stage, and also correlated with NSCLC lymph-node metastasis. In vitro functional assays demonstrated that modulation of miR-196a expression affected NSCLC cell proliferation, migration and invasion. Our analysis showed that miR-196a suppressed the expression of HOXA5 both at the mRNA and protein levels, and luciferase assays confirmed that miR-196a directly bound to the 3’untranslated region of HOXA5. Knockdown of HOXA5 expression in A549 cells using RNAi was shown to promote NSCLC cell proliferation, migration and invasion. Finally, we observed an inverse correlation between HOXA5 and miR-196a expression in NSCLC tissues.
Conclusions
Our findings indicate that miR-196a is significantly up-regulated in NSCLC tissues, and regulates NSCLC cell proliferation, migration and invasion, partially via the down-regulation of HOXA5. Thus, miR-196a may represent a potential therapeutic target for NSCLC intervention.
doi:10.1186/1471-2407-12-348
PMCID: PMC3503718  PMID: 22876840
Non-small cell lung cancer; miR-196a; Proliferation; Invasion; HOXA5
3.  The efficacy of TACE combined sorafenib in advanced stages hepatocellullar carcinoma 
BMC Cancer  2012;12:263.
Background
The long-term survival in hepatocellullar carcinoma (HCC) patients after transarterial chemoembolization (TACE) remains dismal due to local and/or regional recurrence as well as distant metastasis. The efficacy of sorafenib in advanced HCC has been demonstrated and brought great hope. Recently, the use of sorafenib in combination with TACE for BCLC stage B and C HCC patients was recommended. However, data on this dual-modality treatment is little, and its advantage over TACE alone has not been addressed. The present study sought to understand the efficacy of the combination of TACE and sorafenib in the treatment of advanced HCC.
Methods
Between June 2008 and Feb 2011, 45 patients with advanced HCC were enrolled and treated with sorafenib in combination with TACE according to an institutional protocol of the Zhongshan hospital, Fudan University. The control group of 45 other HCC patients with similar characteristics treated with TACE alone in the same period of time in our institute were selected for retrospective comparison of the treatment outcomes especially overall survival time. Adverse reactions induced by sorafenib were observed and recorded.
Results
The median overall survival time of the combined treatment group was 27 (95% Confidence Interval: 21.9–32.1) months, and that of TACE alone group was 17 months (95% Confidence Interval: 8.9–25.0) months (P = 0.001). Patients required significantly less frequent TACE for their symptomatic treatment after the initiation of sorafenib therapy. The most common adverse events associated with sorafenib were hand-foot skin reaction, rash and diarrhea. Of CTCAE grade IV or V toxicity was observed.
Conclusion
TACE combined sorafenib significantly prolonged median overall survival time of patients with advanced HCC.
doi:10.1186/1471-2407-12-263
PMCID: PMC3411397  PMID: 22721173
4.  Adeno-associated virus-mediated doxycycline-regulatable TRAIL expression suppresses growth of human breast carcinoma in nude mice 
BMC Cancer  2012;12:153.
Background
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) functions as a cytokine to selectively kill various cancer cells without toxicity to most normal cells. Numerous studies have demonstrated the potential use of recombinant soluble TRAIL as a cancer therapeutic agent. We have showed previous administration of a recombinant adeno-associated virus (rAAV) vector expressing soluble TRAIL results in an efficient suppression of human tumor growth in nude mice. In the present study, we introduced Tet-On gene expression system into the rAAV vector to control the soluble TRAIL expression and evaluate the efficiency of the system in cancer gene therapy.
Methods
Controllability of the Tet-On system was determined by luciferase activity assay, and Western blotting and enzyme-linked immunoabsorbent assay. Cell viability was determined by MTT assay. The breast cancer xenograft animal model was established and recombinant virus was administrated through tail vein injection to evaluate the tumoricidal activity.
Results
The expression of soluble TRAIL could be strictly controlled by the Tet-On system in both normal and cancer cells. Transduction of human cancer cell lines with rAAV-TRE-TRAIL&rAAV-Tet-On under the presence of inducer doxycycline resulted in a considerable cell death by apoptosis. Intravenous injection of the recombinant virus efficiently suppressed the growth of human breast carcinoma in nude mice when activated by doxycycline.
Conclusion
These data suggest that rAAV-mediated soluble TRAIL expression under the control of the Tet-On system is a promising strategy for breast cancer therapy.
doi:10.1186/1471-2407-12-153
PMCID: PMC3404920  PMID: 22530952
Controllable gene expression; Tet-On; TRAIL; Adeno-associated virus; Gene therapy
5.  Synergistic antitumor effect of AAV-mediated TRAIL expression combined with cisplatin on head and neck squamous cell carcinoma 
BMC Cancer  2011;11:54.
Background
Adeno-associated virus-2 (AAV-2)-mediated gene therapy is quite suitable for local or regional application in head and neck cancer squamous cell carcinoma (HNSCC). However, its low transduction efficiency has limited its further development as a therapeutic agent. DNA damaging agents have been shown to enhance AAV-mediated transgene expression. Cisplatin, one of the most effective chemotherapeutic agents, has been recognized to cause cancer cell death by apoptosis with a severe toxicity. This study aims to evaluate the role of cisplatin in AAV-mediated tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) expression and the effect on HNSCC both in vitro and in vivo.
Methods
Five human HNSCC cell lines were treated with recombinant soluble TRAIL (rsTRAIL) and infected with AAV/TRAIL to estimate the sensitivity of the cancer cells to TRAIL-induced cytotoxicity. KB cells were infected with AAV/EGFP with or without cisplatin pretreatment to evaluate the effect of cisplatin on AAV-mediated gene expression. TRAIL expression was detected by ELISA and Western blot. Cytotoxicity was measured by MTT assay and Western blot analysis for caspase-3 and -8 activations. Following the in vitro experiments, TRAIL expression and its tumoricidal activity were analyzed in nude mice with subcutaneous xenografts of HNSCC.
Results
HNSCC cell lines showed different sensitivities to rsTRAIL, and KB cells possessed both highest transduction efficacy of AAV and sensitivity to TRAIL among five cell lines. Preincubation of KB cells with subtherapeutic dosage of cisplatin significantly augmented AAV-mediated transgene expression in a heparin sulfate proteoglycan (HSPG)-dependent manner. Furthermore, cisplatin enhanced the killing efficacy of AAV/TRAIL by 3-fold on KB cell line. The AAV mediated TRAIL expression was observed in the xenografted tumors and significantly enhanced by cisplatin. AAV/TRAIL suppressed the tumors growth and cisplatin augmented the tumoricidal activity by two-fold. Furthermore, Combination treatment reduced cisplatin-caused body weight loss in nude mice.
Conclusion
The combination of AAV-mediated TRAIL gene expression and cisplatin had synergistic therapeutic effects on head and neck cancers and reduced the potential toxicity of cisplatin. These findings suggest that the combination of AAV/TRAIL and cisplatin may be a promising strategy for HNSCC therapy.
doi:10.1186/1471-2407-11-54
PMCID: PMC3044652  PMID: 21291526
6.  Induction of cell cycle arrest at G1 and S phases and cAMP-dependent differentiation in C6 glioma by low concentration of cycloheximide 
BMC Cancer  2010;10:684.
Background
Differentiation therapy has been shown effective in treatment of several types of cancer cells and may prove to be effective in treatment of glioblastoma multiforme, the most common and most aggressive primary brain tumor. Although extensively used as a reagent to inhibit protein synthesis in mammalian cells, whether cycloheximide treatment leads to glioma cell differentiation has not been reported.
Methods
C6 glioma cell was treated with or without cycloheximide at low concentrations (0.5-1 μg/ml) for 1, 2 and 3 days. Cell proliferation rate was assessed by direct cell counting and colony formation assays. Apoptosis was assessed by Hoechst 33258 staining and FACS analysis. Changes in several cell cycle regulators such as Cyclins D1 and E, PCNA and Ki67, and several apoptosis-related regulators such as p53, p-JNK, p-AKT, and PARP were determined by Western blot analysis. C6 glioma differentiation was determined by morphological characterization, immunostaining and Western blot analysis on upregulation of GFAP and o p-STAT3 expression, and upregulation of intracellular cAMP.
Results
Treatment of C6 cell with low concentration of cycloheximide inhibited cell proliferation and depleted cells at both G2 and M phases, suggesting blockade at G1 and S phases. While no cell death was observed, cells underwent profound morphological transformation that indicated cell differentiation. Western blotting and immunostaining analyses further indicated that changes in expression of several cell cycle regulators and the differentiation marker GFAP were accompanied with cycloheximide-induced cell cycle arrest and cell differentiation. Increase in intracellular cAMP, a known promoter for C6 cell differentiation, was found to be elevated and required for cycloheximide-promoted C6 cell differentiation.
Conclusion
Our results suggest that partial inhibition of protein synthesis in C6 glioma by low concentration of cycloheximide induces cell cycle arrest at G1 and M phases and cAMP-dependent cell differentiation.
doi:10.1186/1471-2407-10-684
PMCID: PMC3009684  PMID: 21159181
7.  MicroRNA-100 is a potential molecular marker of non-small cell lung cancer and functions as a tumor suppressor by targeting polo-like kinase 1 
BMC Cancer  2012;12:519.
Background
Polo-like kinase 1 (PLK1) is highly expressed in many human cancers and regulates critical steps in mitotic progression. Previously, we have reported that PLK1 was overexpressed in non-small cell lung cancer (NSCLC), but the underlying molecular mechanisms are not well understood. By using microRNA (miR) target prediction algorithms, we identified miR-100 that might potentially bind the 3’-untranslated region of PLK1 transcripts. The purpose of this study was to investigate the roles of miR-100 and its association with PLK1 in NSCLC development.
Methods
Taqman real-time quantitative RT-PCR assay was performed to detect miR-100 expression 10 NSCLC tissues and corresponding nontumor tissues. Additionally, the expression of miR-100 in 110 NSCLC tissues and its correlation with clinicopathological factors or prognosis of patients was analyzed. Finally, the effects of miR-100 expression on growth, apoptosis and cell cycle of NSCLC cells by posttranscriptionally regulating PLK1 expression were determined.
Results
MiR-100 was significantly downregulated in NSCLC tissues, and low miR-100 expression was found to be closely correlated with higher clinical stage, advanced tumor classification and lymph node metastasis of patients. The overall survival of NSCLC patients with low miR-100 was significantly lower than that of those patients with high miR-100, and univariate and multivariate analyses indicated that low miR-100 expression might be a poor prognostic factor. Also, miR-100 mimics could lead to growth inhibition, G2/M cell cycle arrest and apoptosis enhancement in NSCLC cells. Meanwhile, miR-100 mimics could significantly inhibit PLK1 mRNA and protein expression and reduce the luciferase activity of a PLK1 3’ untranslated region-based reporter construct in A549 cells. Furthermore, small interfering RNA (siRNA)-mediated PLK1 downregulation could mimic the effects of miR-100 mimics while PLK1 overexpression could partially rescue the phenotypical changes of NSCLC cells induced by miR-100 mimics.
Conclusions
Our findings indicate that low miR-100 may be a poor prognostic factor for NSCLC patients and functions as a tumor suppressor by posttranscriptionally regulating PLK1 expression.
doi:10.1186/1471-2407-12-519
PMCID: PMC3521172  PMID: 23151088
8.  Herpes zoster is associated with an increased risk of subsequent lymphoid malignancies - A nationwide population-based matched-control study in Taiwan 
BMC Cancer  2012;12:503.
Background
Infectious agents have been shown to contribute to the development of lymphoid malignancies. The different distribution of lymphoid malignancies in Asian and Western populations suggests possibly different etiologies in Asian populations. Herpes zoster infection, commonly seen in immunocompromised persons, has been reported to be associated with lymphoid malignancies in retrospective case–control studies from Western populations, but the results are controversial and large-scale prospective studies from Asian populations are lacking.
Methods
A nationwide population-based matched-controlled prospective study on Taiwanese patients was performed using the National Health Insurance Research Database from 1996 to 2007. Herpes zoster and malignancies were defined by compatible ICD-9-CM (International Classification of Disease, 9th Revision, Clinical Modification) codes. Patients who had been diagnosed with any malignancies before herpes zoster, with known viral infections including human immunodeficiency virus, and duration from herpes zoster to diagnosis of malignancies less than 6 months were excluded.
Results
Of 42,498 patients with herpes zoster prior to the diagnosis of any malignancies, the cumulative incidence for lymphoid malignancies was 0.11% (n = 48), compared with 0.06% (n = 106) in 169,983 age- and gender-matched controls (univariate hazard ratio (HR): 1.82, 95%CI: 1.29-2.55). The most common lymphoid malignancy was non-Hodgkin’s lymphoma (60.4%, n = 29), followed by multiple myeloma (27.1%, n = 13). Risk for developing lymphoid malignancies is significantly higher in herpes zoster patients (log rank P = 0.005). After adjusting for presence of any comorbidities in Charlson comorbidity index, time-dependent covariate for herpes group, and income category using Cox proportional hazard regressions, herpes zoster patients had an increased risk of developing lymphoid malignancies (adjusted HR: 1.68, 95%CI: 1.35-2.42, P = 0.0026), but did not have an increased risk of developing non-lymphoid malignancies (adjusted HR: 1.00, 95%CI: 0.91-1.05, P = 0.872).
Conclusion
Preceding herpes zoster infection is an independent risk marker for subsequent lymphoid malignancies in Taiwanese subjects. Further studies are warranted for pathogenesis exploration and preventive strategies in Asian populations.
doi:10.1186/1471-2407-12-503
PMCID: PMC3531246  PMID: 23114019
Herpes zoster; Lymphoma; Leukemia; Epidemiology; Taiwan
9.  An association between hOGG1 Ser326Cys polymorphism and the risk of bladder cancer in non-smokers: a meta-analysis 
BMC Cancer  2012;12:335.
Background
Bladder cancer results from complex interactions between many genetic and environment factors. The polymorphism Ser326Cys in hOGG1 gene has been reported to be associated with bladder cancer in some studies, though the results remain inconclusive. To explore this relationship of hOGG1 polymorphism and the susceptibility for bladder cancer and the impact of smoking exposures, a cumulative meta-analysis was performed in this study.
Methods
We extracted the data from the Pubmed database up to January 9, 2012 using the search phrases “hOGG1, Ser326Cys polymorphism and bladder cancer”. Seven case–control studies were identified, including 2474 patients and 2408 controls. Four of them provided the analysis of smoking effects, with 1372 smokers and 947 non-smokers. The odds ratios (ORs) and associated 95 % confidence intervals (CIs) were calculated using fixed- or random- effects models.
Results
Regarding the overall association between the hOGG1 326Cys allele and bladder cancer risk, the meta-analysis did not reveal a significant effect in the additive model (OR: 1.06, 95 % CI: 0.96-1.26; p = 0.49), the recessive genetic model (OR: 1.05, 95 % CI: 0.65-1.70; p = 0.85) or the dominant genetic model (OR: 1.07, 95 % CI: 0.87-1.32; p = 0.53). Similarly, no significant relationship was observed in the stratified analysis by ethnicity, study design and Hardy-Weinberg equilibrium (all p > 0.05). In the non-smokers, however, hOGG1 326Cys allele significantly increased the risk for bladder cancer and the ORs in the additive model, homozygote contrast and recessive genetic model were 1.59 (p = 0.02), 2.53(p = 0.003) and 2.41(p = 0.0005), respectively. Nevertheless, in the smoker subgroup, similar findings could not be found in all genetic models (all p > 0.05).
Conclusions
The association between the hOGG1 326Cys allele and bladder cancer was significant in non-smoker population, while was non-detectable in common or smoker populations. This meta-analysis suggests that the hOGG1 Ser326Cys polymorphism may be a risk factor for bladder cancer without exposure to smoking. Further functional studies are needed to elucidate the gene polymorphism-bladder cancer relationship and gene-environment interactions.
doi:10.1186/1471-2407-12-335
PMCID: PMC3487852  PMID: 22857644
10.  CD133: a potential indicator for differentiation and prognosis of human cholangiocarcinoma 
BMC Cancer  2011;11:320.
Background
CD133 is known to be a cancer stem cell (CSC) marker. However, recent studies have revealed that CD133 is not restricted to CSC but to be expressed not only in human normal tissues but also in some cancers and could serve as a prognostic factor for the patients. Nevertheless, the expression of CD133 in human cholangiocarcinoma (CC) is rare and our study is to detect the expression and explore the potential functions of CD133 in human CC.
Methods
Fifty-nine cases, comprised of 5 normal liver tissues and 54 consecutive CC specimens (21 well-differentiated, 12 moderately-differentiated and 21 poorly-differentiated), were included in the study. Immunohistochemical stainning with CD133 protein was carried out, and statistical analyses were performed.
Results
CD133 was found to express in all 5 normal livers and 40 out of 54 (74%) CC tissues with different subcellular localization. In the well, moderately and poorly differentiated cases, the numbers of CD133 positive cases were 19 (19 of 21, 90%), 10 (10 of 12, 83%) and 11 (11 of 21, 52%) respectively. Further statistical analyses indicated that the expression and different subcellular localization of CD133 were significantly correlated with the differentiation status of tumors (P = 0.004, P = 0.009). Among 23 patients followed up for survival, the median survival was 4 months for fourteen CD133 negative patients but 14 months for nine CD133 positive ones. In univariate survival analysis, CD133 negative expression correlated with poor prognosis while CD133 positive expression predicted a favorable outcome of CC patients (P = 0.001).
Conclusions
Our study demonstrates that CD133 expression correlates with the differentiation of CC and indicates that CD133 is a potential indicator for differentiation and prognosis of human CC.
doi:10.1186/1471-2407-11-320
PMCID: PMC3161038  PMID: 21798073
CD133; Cholangiocarcinoma; Immunohistochemistry; Differentiation; Prognosis
11.  NDRG2 inhibits hepatocellular carcinoma adhesion, migration and invasion by regulating CD24 expression 
BMC Cancer  2011;11:251.
Background
The prognosis of most hepatocellular carcinoma (HCC) patients is poor due to the high metastatic rate of the disease. Understanding the molecular mechanisms underlying HCC metastasis is extremely urgent. The role of CD24 and NDRG2 (N-myc downstream-regulated gene 2), a candidate tumor suppressor gene, has not yet been explored in HCC.
Methods
The mRNA and protein expression of CD24 and NDRG2 was analyzed in MHCC97H, Huh7 and L-02 cells. Changes in cell adhesion, migration and invasion were detected by up- or down-regulating NDRG2 by adenovirus or siRNA. The expression pattern of NDRG2 and CD24 in HCC tissues and the relationship between NDRG2 and HCC clinical features was analyzed by immunohistochemical and western blotting analysis.
Results
NDRG2 expression was negatively correlated with malignancy in HCC. NDRG2 exerted anti-tumor activity by regulating CD24, a molecule that mediates cell-cell interaction, tumor proliferation and adhesion. NDRG2 up-regulation decreased CD24 expression and cell adhesion, migration and invasion. By contrast, NDRG2 down-regulation enhanced CD24 expression and cell adhesion, migration and invasion. Immunohistochemical analysis of 50 human HCC clinical specimens showed a strong correlation between NDRG2 down-regulation and CD24 overexpression (P = 0.04). In addition, increased frequency of NDRG2 down-regulation was observed in patients with elevated AFP serum level (P = 0.006), late TNM stage (P = 0.009), poor differentiation grade (P = 0.002), tumor invasion (P = 0.004) and recurrence (P = 0.024).
Conclusions
Our findings indicate that NDRG2 and CD24 regulate HCC adhesion, migration and invasion. The expression level of NDRG2 is closely related to the clinical features of HCC. Thus, NDRG2 plays an important physiological role in HCC metastasis.
doi:10.1186/1471-2407-11-251
PMCID: PMC3128008  PMID: 21676268
12.  β-Elemene-induced autophagy protects human gastric cancer cells from undergoing apoptosis 
BMC Cancer  2011;11:183.
Background
β-Elemene, a compound found in an herb used in traditional Chinese medicine, has shown promising anti-cancer effects against a broad spectrum of tumors. The mechanism by which β-elemene kills cells remains unclear. The aim of the present study is to investigate the anti-tumor effect of β-elemene on human gastric cancer cells and the molecular mechanism involved.
Results
β-Elemene inhibited the viability of human gastric cancer MGC803 and SGC7901 cells in a dose-dependent manner. The suppression of cell viability was due to the induction of apoptosis. A robust autophagy was observed in the cells treated with β-elemene; it was characterized by the increase of punctate LC3 dots, the cellular morphology, and the increased levels of LC3-II protein. Further study showed that β-elemene treatment up-regulated Atg5-Atg12 conjugated protein but had little effect on other autophagy-related proteins. PI3K/Akt/mTOR/p70S6K1 activity was inhibited by β-elemene. Knockdown of Beclin 1 with small interfering RNA, or co-treatment with the autophagy inhibitor, 3-methyladenine or chlorochine enhanced significantly the antitumor effects of β-elemene.
Conclusions
Our data provides the first evidence that β-elemene induces protective autophagy and prevents human gastric cancer cells from undergoing apoptosis. A combination of β-elemene with autophagy inhibitor might thus be a useful therapeutic option for advanced gastric cancer.
doi:10.1186/1471-2407-11-183
PMCID: PMC3115914  PMID: 21595977
13.  Oridonin induces apoptosis and senescence in colorectal cancer cells by increasing histone hyperacetylation and regulation of p16, p21, p27 and c-myc 
BMC Cancer  2010;10:610.
Background
Oridonin, a tetracycline diterpenoid compound, has the potential antitumor activities. Here, we evaluate the antitumor activity and action mechanisms of oridonin in colorectal cancer.
Methods
Effects of oridonin on cell proliferation were determined by using a CCK-8 Kit. Cell cycle distribution was determined by flow cytometry. Apoptosis was examined by analyzing subdiploid population and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. Senescent cells were determined by senescence-associated β-galactosidase activity analysis. Semi-quantitative RT-PCR was used to examine the changes of mRNA of p16, p21, p27 and c-myc. The concomitant changes of protein expression were analyzed with Western blot. Expression of AcH3 and AcH4 were examined by immunofluorescence staining and Western blots. Effects of oridonin on colony formation of SW1116 were examined by Soft Agar assay. The in vivo efficacy of oridonin was detected using a xenograft colorectal cancer model in nude mice.
Results
Oridonin induced potent growth inhibition, cell cycle arrest, apoptosis, senescence and colony-forming inhibition in three colorectal cancer cell lines in a dose-dependent manner in vitro. Daily i.p. injection of oridonin (6.25, 12.5 or 25 mg/kg) for 28 days significantly inhibited the growth of SW1116 s.c. xenografts in BABL/C nude mice. With western blot and reverse transcription-PCR, we further showed that the antitumor activities of oridonin correlated with induction of histone (H3 and H4) hyperacetylation, activation of p21, p27 and p16, and suppression of c-myc expression.
Conclusion
Oridonin possesses potent in vitro and in vivo anti-colorectal cancer activities that correlated with induction of histone hyperacetylation and regulation of pathways critical for maintaining growth inhibition and cell cycle arrest. Therefore, oridonin may represent a novel therapeutic option in colorectal cancer treatment.
doi:10.1186/1471-2407-10-610
PMCID: PMC2992521  PMID: 21054888
14.  Association of genetic polymorphisms in the interleukin-10 promoter with risk of prostate cancer in Chinese 
BMC Cancer  2010;10:456.
Background
Recent studies identified an increased risk of prostate cancer (PCa) in Caucasian men harboring polymorphisms of genes involved in innate immunity and inflammation. This study was designed to assess whether single nucleotide polymorphisms in the IL-10 promoter play a role in predisposing individuals to PCa in a Chinese population.
Methods
We genotyped three SNPs of the IL-10 promoter (-1082A/G, -819T/C and -592A/C) using polymerase chain reaction-restriction fragment length polymorphism analysis in 262 subjects with PCa and 270 age-matched healthy controls. Odds ratio and 95% confidence interval were determined by logistic regression for the associations between IL-10 genotypes and haplotypes with the risk of PCa and advanced PCa grade.
Results
No significant differences in allele frequency or genotype distribution were observed for any of the IL-10 SNPs between PCa patients and control subjects. Significantly higher frequencies of -1082G, -819C and -592C allele and GCC haplotype were observed, however, in early stage patients in comparison to advanced PCa patients (for -1082 G, 13.9% vs 6.1%, OR = 2.48, P = 0.005; for -819 C 40.3% vs 30.8%, OR = 1.51, P = 0.043; for -512C, 40.3% vs 30.8%, OR = 1.51, P = 0.043; and for haplotype GCC 11.1%vs 5.1%, OR = 2.66, P = 0.008, respectively).
Conclusions
Our results identify that IL-10 promoter polymorphisms might not be a risk factor for PCa in Chinese cohorts, but rather incidence of polymorphisms associates with PCa grade, suggesting that IL-10 expression may impact PCa progression.
doi:10.1186/1471-2407-10-456
PMCID: PMC2936329  PMID: 20735825
15.  Health-related quality of life in glioma patients in China 
BMC Cancer  2010;10:305.
Background
Health-related quality of life (HRQOL) has been increasingly emphasized in cancer patients. There are no reports comparing baseline HRQOL of different subgroups of glioma patients prior to surgery.
Methods
HRQOL assessments by the standard Chinese version of the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire 30 (EORTC QLQ-C30, version 3.0), the Mini-Mental State Examination and Karnofsky Performance Status were obtained from glioma patients prior to surgery.
Results
Ninety-two pathologically confirmed glioma patients were recruited. There were 84.8% patients with emotional impairment, 75% with social and cognitive impairment, 70.7% with physical impairment, and 50% with role impairment. Eighty-two percent of patients reported fatigue symptoms, 72.8% reported pain, 50% reported appetite loss, 39.1% reported insomnia, and 36.9% reported nausea/vomiting, whereas other symptoms (dyspnea, diarrhea, constipation) in the QLQ-C30 were reported by fewer than 30% of patients. Fatigue and pain symptoms and all "functioning" scales were strongly correlated with global health status/quality of life (QoL). Fatigue was strongly related to all functioning scales, pain, appetite loss, and global health status/QoL. No difference in baseline HRQOL prior to surgery was reported between females and males, among different lesion locations, or between normal- and abnormal-cognition subgroups of glioma patients. Age, KPS, WHO grade, and tumor recurrence significantly affected HRQOL in glioma patients.
Conclusions
These data provided the baseline HRQOL in glioma patients prior to surgery in China. Most pre-surgery glioma patients indicated emotional, social, cognitive, physical, and role impairment. Fatigue, pain, appetite loss, insomnia, and nausea/vomiting were common in these patients. The fatigue and pain symptoms and all types of functioning strongly affected global health status/QoL. Old age, worse performance status, WHO grade IV and tumor recurrence had deleterious effects on HRQOL.
doi:10.1186/1471-2407-10-305
PMCID: PMC2910687  PMID: 20565883
16.  Residual hepatocellular carcinoma after oxaliplatin treatment has increased metastatic potential in a nude mouse model and is attenuated by Songyou Yin 
BMC Cancer  2010;10:219.
Background
The opposite effects of chemotherapy, which enhance the malignancy of treated cancers such as hepatocellular carcinoma (HCC), are not well understood. We investigated this phenomenon and corresponding mechanisms to develop a novel approach for improving chemotherapy efficacy in HCC.
Methods
Human hepatocellular carcinoma cell lines HepG2 (with low metastatic potential) and MHCC97L (with moderate metastatic potential) were used for the in vitro study. An orthotopic nude mouse model of human HCC was developed using MHCC97L cells. We then assessed the metastatic potential of surviving tumor cells after in vitro and in vivo oxaliplatin treatment. The molecular changes in surviving tumor cells were evaluated by western blot, immunofluorescence, and immunohistochemistry. The Chinese herbal extract Songyou Yin (composed of five herbs) was investigated in vivo to explore its effect on the metastatic potential of oxaliplatin-treated cancer cells.
Results
MHCC97L and HepG2 cells surviving oxaliplatin treatment showed enhanced migration and invasion in vitro. Residual HCC after in vivo oxaliplatin treatment demonstrated significantly increased metastasis to the lung (10/12 vs. 3/12) when re-inoculated into the livers of new recipient nude mice. Molecular changes consistent with epithelial-mesenchymal transition (EMT) were observed in oxaliplatin-treated tumor tissues and verified by in vitro experiments. The Chinese herbal extract Songyou Yin (4.2 and 8.4 g/kg) attenuated EMT and inhibited the enhanced metastatic potential of residual HCC in nude mice (6/15 vs. 13/15 and 3/15 vs. 13/15, respectively).
Conclusions
The surviving HCC after oxaliplatin treatment underwent EMT and demonstrated increased metastatic potential. Attenuation of EMT by Songyou Yin may improve the efficacy of chemotherapy in HCC.
doi:10.1186/1471-2407-10-219
PMCID: PMC2880993  PMID: 20487542
17.  Vascular endothelial growth factor C promotes cervical cancer metastasis via up-regulation and activation of RhoA/ROCK-2/moesin cascade 
BMC Cancer  2010;10:170.
Background
The elevated expression of vascular endothelial growth factor C (VEGF-C) is correlated with clinical cervical cancer metastasis and patient survival, which is interpreted by VEGF-C functions to stimulate angiogenesis and lymphatic genesis. However, the direct impact of VEGF-C on cervical cancer cell motility remains largely unknown.
Methods
In this study, we investigated the effects of VEGF-C on actin cytoskeleton remodeling and on cervical cancer cell migration and invasion and how the actin-regulatory protein, moesin regulated these effects through RhoA/ROCK-2 signaling pathway.
Results
On cervical carcinoma cell line SiHa cells, exposure of VEGF-C triggered remodeling of the actin cytoskeleton and the formation of membrane ruffles, which was required for cell movement. VEGF-C significantly enhanced SiHa cells horizontal migration and three-dimensional invasion into matrices. These actions were dependent on increased expression and phosphorylation of the actin-regulatory protein moesin and specific moesin siRNA severely impaired VEGF-C stimulated-cell migration. The extracellular small GTPase RhoA/ROCK-2 cascade mediated the increased moesin expression and phosphorylation, which was discovered by the use of Y-27632, a specific inhibitor of Rho kinase and by transfected constitutively active, dominant-negative RhoA as well as ROCK-2 SiRNA. Furthermore, in the surgical cervical specimen from the patients with FIGO stage at cervical intra-epithelial neoplasia and I-II cervical squamous cell carcinoma, the expression levels of moesin were found to be significantly correlated with tumor malignancy and metastasis.
Conclusions
These results implied that VEGF-C promoted cervical cancer metastasis by upregulation and activation of moesin protein through RhoA/ROCK-2 pathway. Our findings offer new insight into the role of VEGF-C on cervical cancer progression and may provide potential targets for cervical cancer therapy.
doi:10.1186/1471-2407-10-170
PMCID: PMC2873393  PMID: 20429915
18.  Long-term results of intensity-modulated radiotherapy concomitant with chemotherapy for hypopharyngeal carcinoma aimed at laryngeal preservation 
BMC Cancer  2010;10:102.
Background
The objective of this retrospective study is to investigate laryngeal preservation and long-term treatment results in hypopharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT) combined with chemotherapy.
Methods
Twenty-seven patients with hypopharyngeal carcinoma (stage II-IV) were enrolled and underwent concurrent chemoradiotherapy. The chemotherapy regimens were monthly cisplatin and 5-fluorouracil for six patients and weekly cisplatin for 19 patients. All patients were treated with IMRT with simultaneous integrated boost technique. Acute and late toxicities were recorded based on CTCAE 3.0 (Common Terminology Criteria for Adverse Events).
Results
The median follow-up time for survivors was 53.0 months (range 36-82 months). The initial complete response rate was 85.2%, with a laryngeal preservation rate of 63.0%. The 5-year functional laryngeal, local-regional control, disease-free and overall survival rates were 59.7%, 63.3%, 51.0% and 34.8%, respectively. The most common greater than or equal to grade 3 acute and late effects were dysphagia (63.0%, 17 of 27 patients) and laryngeal stricture (18.5%, 5 of 27 patients), respectively. Patients belonging to the high risk group showed significantly higher risk of tracheostomy compared to the low risk group (p = 0.014).
Conclusions
After long-term follow-up, our results confirmed that patients with hypopharyngeal carcinoma treated with IMRT concurrent with platinum-based chemotherapy attain high functional laryngeal and local-regional control survival rates. However, the late effect of laryngeal stricture remains a problem, particularly for high risk group patients.
doi:10.1186/1471-2407-10-102
PMCID: PMC3087314  PMID: 20298550
19.  Sequence variations in DNA repair gene XPC is associated with lung cancer risk in a Chinese population: a case-control study 
BMC Cancer  2007;7:81.
Background
The nucleotide excision repair (NER) protein, xeroderma pigmentosum C (XPC), participates in recognizing DNA lesions and initiating DNA repair in response to DNA damage. Because mutations in XPC cause a high risk of cancer in XP patients, we hypothesized that inherited sequence variations in XPC may alter DNA repair and thus susceptibility to cancer.
Methods
In this hospital-based case-control study, we investigated five XPC tagging, common single nucleotide polymorphisms (tagging SNPs) in 1,010 patients with newly diagnosed lung cancer and 1,011 matched cancer free controls in a Chinese population.
Results
In individual tagging SNP analysis, we found that rs3731055AG+AA variant genotypes were associated with a significantly decreased risk of lung adenocarcinoma [adjusted odds ratio (OR), 0.71; 95% confidence interval (CI), 0.56–0.90] but an increased risk of small cell carcinomas [adjusted OR, 1.79; 95% CI, 1.05–3.07]. Furthermore, we found that haplotype ACCCA was associated with a decreased risk of lung adenocarcinoma [OR, 0.78; 95% CI, 0.62–0.97] but an increased risk of small cell carcinomas [OR, 1.68; 95% CI, 1.04–2.71], which reflected the presence of rs3731055A allele in this haplotype. Further stratified analysis revealed that the protective effect of rs3731055AG+AA on risk of lung adenocarcinoma was more evident among young subjects (age ≤ 60) and never smokers.
Conclusion
These results suggest that inherited sequence variations in XPC may modulate risk of lung cancer, especially lung adenocarcinoma, in Chinese populations. However, these findings need to be verified in larger confirmatory studies with more comprehensively selected tagging SNPs.
doi:10.1186/1471-2407-7-81
PMCID: PMC1884164  PMID: 17498315
20.  Pancreatic cancer clusters and arsenic-contaminated drinking water wells in Florida 
BMC Cancer  2013;13:111.
Background
We sought to identify high-risk areas of pancreatic cancer incidence, and determine if clusters of persons diagnosed with pancreatic cancer were more likely to be located near arsenic-contaminated drinking water wells.
Methods
A total of 5,707 arsenic samples were collected from December 2000 to May 2008 by the Florida Department of Health, representing more than 5,000 individual privately owned wells. During that period, 0.010 ppm (10 ppb) or greater arsenic levels in private well water were considered as the threshold based on standard of United States Environmental Protection Agency (EPA). Spatial modeling was applied to pancreatic cancer cases diagnosed between 1998–2002 in Florida (n = 11,405). Multivariable logistic regression was used to determine if sociodemographic indicators, smoking history, and proximity to arsenic-contaminated well sites were associated with residence at the time of pancreatic cancer diagnosis occurring within versus outside a cluster.
Results
Spatial modeling identified 16 clusters in which 22.6% of all pancreatic cancer cases were located. Cases living within 1 mile of known arsenic-contaminated wells were significantly more likely to be diagnosed within a cluster of pancreatic cancers relative to cases living more than 3 miles from known sites (odds ratio = 2.1 [95% CI = 1.9, 2.4]).
Conclusions
Exposure to arsenic-contaminated drinking water wells may be associated with an increased risk of pancreatic cancer. However, case–control studies are needed in order to confirm the findings of this ecological analysis. These cluster areas may be appropriate to evaluate pancreatic cancer risk factors, and to perform targeted screening and prevention studies.
doi:10.1186/1471-2407-13-111
PMCID: PMC3600048
Pancreatic cancer; Screening; Arsenic; Epidemiology
21.  Genetic oxidative stress variants and glioma risk in a Chinese population: a hospital-based case–control study 
BMC Cancer  2012;12:617.
Background
The oxidative stress mechanism is of particular interest in the pathogenesis of glioma, given the high rate of oxygen metabolism in the brain. Potential links between polymorphisms of antioxidant genes and glioma risk are currently unknown. We therefore investigated the association between polymorphisms in antioxidant genes and glioma risk.
Methods
We examined 16 single nucleotide polymorphisms (SNPs) of 9 antioxidant genes (GPX1, CAT, PON1, NQO1, SOD2/MnSOD, SOD3, and NOS1*2*3) in 384 glioma and 384 control cases in a Chinese hospital-based case–control study. Genotypes were determined using the OpenArray platform, which employs the chip-based Taq-Man genotyping technology. The adjusted odds ratio (OR) and 95% confidence interval (CI) were estimated using unconditional logistic regression.
Results
Using single-locus analysis, we identified four SNPs (SOD2 V16A, SOD3 T58A, GPX1 -46 C/T, and NOS1 3’-UTR) that were significantly associated with the risk of glioma development. To assess the cumulative effects, we performed a combined unfavourable genotype analysis. Compared with the reference group that exhibited no unfavourable genotypes, the medium- and high-risk groups exhibited a 1.86-fold (95% CI, 1.30-2.67) and a 4.86-fold (95% CI, 1.33-17.71) increased risk of glioma, respectively (P-value for the trend < 0.001).
Conclusions
These data suggest that genetic variations in oxidative stress genes might contribute to the aetiology of glioma.
doi:10.1186/1471-2407-12-617
PMCID: PMC3546059  PMID: 23259684
Oxidative stress; Single nucleotide polymorphism; Glioma; SOD2; SOD3; GPX1; NOS1
22.  The role of brevican in glioma: promoting tumor cell motility in vitro and in vivo 
BMC Cancer  2012;12:607.
Background
Malignant glioma is a common primary tumor of the central nervous system. Brevican, an abundant extracellular matrix component in the adult brain, plays a critical role in the process of glioma. The mechanisms for the highly invasive behavior of gliomas are still poorly understood. The aim of this study was to examine whether brevican is a predictor of glioma and its roles in glioma cell motility.
Methods
In this study, immunohistochemistry staining for brevican expression was performed in malignant gliomas and benign controls. We also explored the effects of brevican on cell adhesion and migration in brevican-overexpressed cells. Knockdown of brevican expression was achieved by stable transfection of U251 cells transduced with a construct encoding a short hairpin DNA directed against the brevican gene, which correspondingly, down-regulated the proliferation, invasion and spread of brevican-expressing cells. Moreover, the role of brevican in the growth and progression of glioma was demonstrated by in vivo studies.
Results
Our results provide evidence for the molecular and cellular mechanisms that may underlie the motility-promoting role of brevican in the progression of glioma. The role of brevican as a target for immunotherapy might be taken into consideration in future studies.
Conclusions
This study suggests that expression of brevican is associated with glioma cell adhesion, motility and tumor growth, and also is related to glioma cell differentiation, therefore it may be a marker for malignance degree of glioma
doi:10.1186/1471-2407-12-607
PMCID: PMC3575301  PMID: 23253190
Brevican; Glioma; Astrocytoma; Motility; Tumorigenicity
23.  The role of MMP-1 in breast cancer growth and metastasis to the brain in a xenograft model 
BMC Cancer  2012;12:583.
Background
Brain metastasis is an increasingly common complication for breast cancer patients; approximately 15– 30% of breast cancer patients develop brain metastasis. However, relatively little is known about how these metastases form, and what phenotypes are characteristic of cells with brain metastasizing potential. In this study, we show that the targeted knockdown of MMP-1 in breast cancer cells with enhanced brain metastatic ability not only reduced primary tumor growth, but also significantly inhibited brain metastasis.
Methods
Two variants of the MDA-MB-231 human breast cancer cell line selected for enhanced ability to form brain metastases in nude mice (231-BR and 231-BR3 cells) were found to express high levels of matrix metalloproteinase-1 (MMP-1). Short hairpin RNA-mediated stable knockdown of MMP-1 in 231-BR and 231-BR3 cells were established to analyze tumorigenic ability and metastatic ability.
Results
Short hairpin RNA-mediated stable knockdown of MMP-1 inhibited the invasive ability of MDA-MB 231 variant cells in vitro, and inhibited breast cancer growth when the cells were injected into the mammary fat pad of nude mice. Reduction of MMP-1 expression significantly attenuated brain metastasis and lung metastasis formation following injection of cells into the left ventricle of the heart and tail vein, respectively. There were significantly fewer proliferating cells in brain metastases of cells with reduced MMP-1 expression. Furthermore, reduced MMP-1 expression was associated with decreased TGFα release and phospho-EGFR expression in 231-BR and BR3 cells.
Conclusions
Our results show that elevated expression of MMP-1 can promote the local growth and the formation of brain metastases by breast cancer cells.
doi:10.1186/1471-2407-12-583
PMCID: PMC3526403  PMID: 23217186
Breast cancer; Brain metastasis; MMP-1; TGFα; EGFR
24.  Doxorubicin-enriched, ALDHbr mouse breast cancer stem cells are treatable to oncolytic herpes simplex virus type 1 
BMC Cancer  2012;12:549.
Background
The primary objective of this study was to test whether oncolytic herpes simplex virus type 1 (HSV1) could eradicate chemoresistant cancer stem cells (CSCs).
Methods
The fluorescent aldefluor reagent-based technique was used to identify and isolate ALDHbr cells as CSCs from the 4T1 murine breast cancer cell line. The presence of ALDHbr 4T1 cells was also examined in 4T1 breast cancer transplanted in immune-competent syngeneic mice.
Results
Compared with ALDHlo cells, ALDHbr cells had a markedly higher ability to form tumor spheres in vitro and a higher tumorigenic potential in vivo. ALDHbr cells also exhibited increased doxorubicin resistance in vitro, which correlated with a selective increase in the percentage of ALDHbr cells after doxorubicin treatment and an increased expression of P-glycoprotein (P-gp), a known chemoresistance factor. In contrast, oncolytic HSV1 was able to kill ALDHbr cells in vitro and even more markedly in vivo. Furthermore, in in vivo studies, systemic administration of doxorubicin followed by intratumoral injection of oncolytic HSV1 resulted in much more significant suppression of tumor growth with increased median survival period compared with each treatment given alone (p<0.05). Though more CD8+ T lymphocytes were induced by oncolytic HSV1, no significant specific T cell response against CSCs was detected in vivo.
Conclusions
These results suggested that the use of oncolytic HSV1 following doxorubicin treatment may help eradicate residual chemoresistant CSCs in vivo.
doi:10.1186/1471-2407-12-549
PMCID: PMC3541265  PMID: 23176143
Cancer stem cells; Breast cancer; Chemoresistant; ALDH; Oncolytic virus; Doxorubicin; Herpes simplex virus
25.  Sorafenib modulates the radio sensitivity of hepatocellular carcinoma cells in vitro in a schedule-dependent manner 
BMC Cancer  2012;12:485.
Background
Hepatocellular carcinoma (HCC) has a high incidence and mortality. Radiotherapy and sorafenib have proven effective for HCC. Here, we investigated whether sorafenib modulated the response of HCC cells to irradiation in vitro, effect of timing of sorafenib, and the underlying mechanisms.
Methods
Cell viability of the HCC cell lines, SMMC-7721 and Bel-7402, was examined by the 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2(4-sulfophenyl)-2 H-terazolium (MTT) assays. Clonogenic growth assays of SMMC-7721 and Bel-7402 were determined by colony formation assays. DNA damage was assessed by monitoring γ-HAX foci in irradiated cells with immunofluorescence microscopy, and cell cycle distribution changes were examined by flow cytometry. Effects of sorafenib (15 μM) added 30 min prior to radiation (pre-irradiation sorafenib) of SMMC-7721 and BEL-7402 or 24 h post-irradiation (post-irradiation sorafenib) on irradiated SMMC-7721 and BEL-7402 cells were compared to those of radiation alone or no treatment.
Results
The effect of sorafenib was dependent on its time of addition in relationship to irradiation of cells. Pre-irradiation sorafenib did not significantly affect the viability of SMMC-7221 and BEL-7402 cells compared with irradiation treatment alone. In contrast, post-irradiation sorafenib increased the sensitivity of irradiated SMMC-7221 and BEL-7402 cells significantly in a time-dependent manner. Pre-irradiation sorafenib significantly increased the surviving fraction of SMMC-7221 and BEL-7402 cells in clonogenic assays whereas post-irradiation sorafenib significantly reduced the surviving fractions of SMMC-7221 and BEL-7402 cells. SMMC-7721 cells treated with sorafenib 30 min before irradiation had significantly fewer cells with γ-H2AX foci (23.8 ± 2.9%) than SMMC-7721 cells receiving radiation alone (59.9 ± 2.4; P < 0.001). Similarly, BEL-7402 cells receiving sorafenib prior to irradiation had significantly fewer cells with γ-H2AX foci (46.4 ± 3.8%) than those receiving radiation alone (25.0 ± 3.0%; P < 0.001). In addition, irradiation (6 Gy) caused a significant increase in the percentage of both SMMC-7721 and BEL-7402 cells in G2/M at 12 to 16 h post irradiation, which was markedly delayed by pre-irradiation sorafenib.
Conclusions
Sorafenib combined with irradiation exerted a schedule-dependent effect in HCC cells in vitro, which has significant implications for the combined use of sorafenib and radiotherapy for HCC patients.
doi:10.1186/1471-2407-12-485
PMCID: PMC3488336  PMID: 23088517
Hepatocellular carcinoma; Radiation; Sorafenib; Apoptosis; DNA damage repair

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