The current study was designed to evaluate the sensitivity, feasibility, and effectiveness of the pallidal index (PI) serving as a biomarker of brain manganese (Mn) accumulation, which would be used as an early diagnosis criteria for Mn neurotoxicity.
The weighted mean difference (WMD) of the PI between control and Mn-exposed groups was estimated by using a random-effects or fixed-effects meta-analysis with 95% confidence interval (CI) performed by STATA software version 12.1. Moreover, the R package “metacor” was used to estimate correlation coefficients between PI and blood Mn (MnB).
A total of eight studies with 281 occupationally Mn-exposed workers met the inclusion criteria. Results were pooled and performed with the Meta-analysis. Our data indicated that the PI of the exposed group was significantly higher than that of the control (WMD: 7.76; 95% CI: 4.86, 10.65; I2 = 85.7%, p<0.0001). A random effects model was used to perform meta-analysis. These findings were remarkably robust in the sensitivity analysis, and publication bias was shown in the included studies. Seven out of the eight studies reported the Pearson correlation (r) values. Significantly positive correlation between PI and MnB was observed (r = 0.42; 95% CI, 0.31, 0.52).
PI can be considered as a sensitive, feasible, effective and semi-quantitative index in evaluating brain Mn accumulation. MnB can also augment the evaluation of brain Mn accumulation levels in the near future. However, the results should be interpreted with caution.
A feasible nucleophilic trifluoromethylating protocol has been developed using trifluoroacetaldehyde hydrate as an atom economical trifluoromethyl source. The reaction was found to be applicable to the nucleophilic trifluoromethylation of a broad spectrum of carbonyl compounds with satisfactory yields in general. DFT calculations have been performed to provide mechanistic insight into the present and related reactions employing 2,2,2-trifluoro-1-methoxyethanol and hexafluoroacetone hydrate.
The uPAR·uPA protein-protein interaction (PPI) is involved in signaling and proteolytic events that promote tumor invasion and metastasis. A previous study had identified 4 (IPR-803) from computational screening of a commercial chemical library and shown that the compound inhibited uPAR·uPA PPI in competition biochemical assays and invasion cellular studies. Here, we synthesize 4 to evaluate in vivo pharmacokinetic (PK) and efficacy studies in a murine breast cancer metastasis model. First, we show, using fluorescence polarization and saturation transfer difference (STD) NMR, that 4 binds directly to uPAR with sub-micromolar affinity of 0.2 μM. We show that 4 blocks invasion of breast MDA-MB-231, and inhibits matrix metalloproteinase (MMP) breakdown of the extracellular matrix (ECM). Derivatives of 4 also inhibited MMP activity and blocked invasion in a concentration-dependent manner. 4 also impaired MDA-MB-231 cell adhesion and migration. Extensive in vivo PK studies in NOD-SCID mice revealed a half-life of nearly 5 hours and peak concentration of 5 μM. Similar levels of the inhibitor were detected in tumor tissue up to 10 hours. Female NSG mice inoculated with highly malignant TMD-MDA-MB-231 in their mammary fat pads showed that 4 impaired metastasis to the lungs with only four of the treated mice showing severe or marked metastasis compared to ten for the untreated mice. Compound 4 is a promising template for the development of compounds with enhanced PK parameters and greater efficacy.
Uromodulin (UMOD) genetic variants cause familial juvenile hyperuricemic nephropathy, characterized by hyperuricemia, decreased renal excretion of UMOD and uric acid; such findings suggest a role for UMOD in the regulation of plasma uric acid. We screened common variants across the UMOD locus in two populations, one from a community-based Chinese population, the other from California twins and siblings. Transcriptional activity of promoter variants was estimated in luciferase reporter plasmids transfected into HEK293 cells and mlMCD3 cells. By variance components in twin pairs, uric acid concentration and excretion were heritable traits. In the primary population from Beijing, we identified that carriers of haplotype GCC displayed higher plasma uric acid, and 3 UMOD promoter variants associated with plasma uric acid. UMOD promoter variants displayed reciprocal effects on urine uric acid excretion and plasma uric acid concentration, suggesting a primary effect on renal tubular handling of urate. These UMOD genetic marker-on-trait associations for uric acid were replicated in an independent American population sample. Site-directed mutagenesis at trait-associated UMOD promoter variants altered promoter activity in transfected luciferase reporter plasmids. These results suggest that UMOD promoter variants seem to initiate a cascade of transcriptional and biochemical changes influencing UMOD secretion, eventuating in elevation of plasma uric acid.
Uromodulin; uric acid; Tamm-Horsfall protein; UMOD
The developmental stage-specific expression of the human β-like globin genes has been studied for decades, and many transcriptional factors as well as other important cis elements have been identified. However, little is known about the microRNAs that potentially regulate β-like globin gene expression directly or indirectly during erythropoiesis. In this study, we show that microRNA 23a (miR-23a) and miR-27a promote β-like globin gene expression in K562 cells and primary erythroid cells through targeting of the transcription factors KLF3 and SP1. Intriguingly, miR-23a and miR-27a further enhance the transcription of β-like globin genes through repression of KLF3 and SP1 binding to the β-like globin gene locus during erythroid differentiation. Moreover, KLF3 can bind to the promoter of the miR-23a∼27a∼24-2 cluster and suppress this microRNA cluster expression. Hence, a positive feedback loop comprised of KLF3 and miR-23a promotes the expression of β-like globin genes and the miR-23a∼27a∼24-2 cluster during erythropoiesis.
Nasopharyngeal carcinoma (NPC) is a common tumor in Southern China, but the oncogene mutational status of NPC patients has not been clarified. Using time-of-flight mass spectrometry, 238 mutation hotspots in 19 oncogenes were examined in 123 NPC patients. The relationships between mutational status and clinical data were assessed with a χ2 or Fisher’s exact test. Survival analysis was performed using the Kaplan–Meier method with the log-rank test. In 123 patients, 21 (17.1%) NPC tumors were positive for mutations in eight oncogenes: six patients had PIK3CA mutations (4.9%), five NRAS mutations (4.1%), four KIT mutations (3.3%), two PDGFRA mutations (1.6%), two ABL mutations (1.6%), and one with simultaneous mutations in HRAS, EGFR, and BRAF (1%). Patients with mutations were more likely to relapse or develop metastasis than those with wild-type alleles (P=0.019). No differences or correlations were found in other clinical characteristics or in patient survival. No mutations were detected in oncogenes AKT1, AKT2, CDK, ERBB2, FGFR1, FGFR3, FLT3, JAK2, KRAS, MET, and RET. These results demonstrate an association between NPC and mutations in NRAS, KIT, PIK3CA, PDGFRA, and ABL, which are associated with patient relapse and metastasis.
NPC; oncogene; mutation
Hepatitis C virus (HCV) is a major cause of chronic liver disease. However, little is known about the details of its assembly and secretion. Golgi-related proteins have been recently proven to have a key function in HCV secretion. Golgi protein 73 (GP73), a resident Golgi membrane protein, is a potential serum biomarker for the diagnosis of liver diseases and hepatocellular carcinoma. Previous studies have demonstrated the upregulation of GP73 in the liver samples and sera of HCV-infected patients. However, the function and regulatory mechanism of GP73 in HCV infection at the cellular level remain unknown. In this study, we examined the expression level of GP73 in HCV infected cells and its effect on HCV life cycle in cell culture systems. Both the protein expression and mRNA levels of GP73 significantly increased in HCV subgenomic replicon-harboring cells and HCV-infected cells, which imply that GP73 was upregulated by HCV infection. HCV production was significantly enhanced when GP73 was overexpressed, but dramatically inhibited when GP73 was silenced. However, the overexpression and knockdown of GP73 showed no evident effect on the entry, protein translation, RNA replication, and assembly of HCV, which indicates that GP73 enhanced the secretion process. Moreover, the coiled-coil domain of GP73 was required to increase HCV secretion. GP73 increased and interacted with apolipoprotein E, an identified host factor that assists in HCV secretion. These results demonstrate the critical function of GP73 in HCV secretion and provide new insights into the therapeutic design of antiviral strategies.
MicroRNAs (miRNAs) represent a class of small non-coding regulatory RNAs that play important roles in normal hematopoiesis, including erythropoiesis. Although studies have identified several miRNAs that regulate erythroid commitment and differentiation, we do not understand the mechanism by which the crucial erythroid transcription factors, GATA-1and NF-E2 directly regulate and control differentiation via miRNA pathways. In this study, we identified miR-199b-5p as a key regulator of human erythropoiesis, and its expression was up-regulated during the erythroid differentiation of K562 cells. Furthermore, the increase of miR-199b-5p in erythroid cells occurred in a GATA-1- and NF-E2-dependent manner during erythrocyte maturation. Both GATA-1 and NF-E2 bound upstream of the miR-199b gene locus and activated its transcription. Forced expression of miRNA-199b-5p in K562 cells affected erythroid cell proliferation and maturation. Moreover, we identified c-Kit as a direct target of miR-199b-5p in erythroid cells. Taken together, our results establish a functional link among the erythroid transcription factors GATA-1/NF-E2, miR-199b-5p and c-Kit, and provide new insights into the coupling of transcription and post-transcription regulation in erythroid differentiation.
c-Kit; erythroid differentiation; GATA-1; microRNA-199b-5p; NF-E2
Brucellosis is a serious zoonosis that occurs worldwide, and its diagnosis is typically based on the detection of antibodies against Brucella lipopolysaccharide (LPS). However, the specificity of the LPS-based test is compromised by cross-reactivity with Escherichia coli O157:H7 and Yersinia enterocolitica O:9. Also, diagnosis based on the LPS test cannot differentiate between vaccinated and infected individuals. The detection of the 26-kDa cytosoluble protein (BP26) antibody is considered an alternative that circumvents these drawbacks because it is exclusively expressed by infectious Brucella. A BP26-based enzyme-linked immunosorbent assay (ELISA) has been tried for the diagnosis of Brucella-infected animals and humans, but a few results showed that BP26 couldn't react with all Brucella-positive sera. In order to explore whether different animals could produce antibodies against BP26 after being infected with various Brucella species, we infected sheep, goats, and beef cattle with common virulent reference Brucella species. All sera were collected from the experimental animals and tested using both LPS-based ELISAs and BP26-based ELISAs. The results showed that all Brucella-infected individuals could produce high levels of antibodies against LPS, but only B. melitensis 16M- and B. melitensis M28-infected sheep and B. melitensis 16M- and B. abortus 2308-infected goats could produce antibodies against BP26. Therefore, we concluded that the BP26-based indirect ELISA (i-ELISA) showed both Brucella species and host specificity, which obviously limits its reliability as a substitute for the traditional LPS-based ELISA for the detection of brucellosis.
Multidrug resistance (MDR) mediated by ATP-binding cassette (ABC) transporters through efflux of antineoplastic agents from cancer cells is a major obstacle to successful cancer chemotherapy. The inhibition of these ABC transporters is thus a logical approach to circumvent MDR. There has been intensive research effort to design and develop novel inhibitors for the ABC transporters to achieve this goal. In the present study, we evaluated the ability of UMMS-4 to modulate P-glycoprotein (P-gp/ABCB1)-, breast cancer resistance protein (BCRP/ABCG2)- and multidrug resistance protein (MRP1/ABCC1)-mediated MDR in cancer cells. Our findings showed that UMMS-4, at non-cytotoxic concentrations, apparently circumvents resistance to ABCB1 substrate anticancer drugs in ABCB1-overexpressing cells. When used at a concentration of 20 μmol/L, UMMS-4 produced a 17.53-fold reversal of MDR, but showed no effect on the sensitivity of drug-sensitive parental cells. UMMS-4, however, did not significantly alter the sensitivity of non-ABCB1 substrates in all cells and was unable to reverse ABCG2- and ABCC1-mediated MDR. Additionally, UMMS-4 profoundly inhibited the transport of rhodamine 123 (Rho 123) and doxorubicin (Dox) by the ABCB1 transporter. Furthermore, UMMS-4 did not alter the expression of ABCB1 at the mRNA and protein levels. In addition, the results of ATPase assays showed that UMMS-4 stimulated the ATPase activity of ABCB1. Taken together, we conclude that UMMS-4 antagonizes ABCB1-mediated MDR in cancer cells through direct inhibition of the drug efflux function of ABCB1. These findings may be useful for the development of safer and more effective MDR modulator.
UMMS-4; multidrug resistance; ATP binding cassette transporters; ABCB1; chemotherapeutic drugs
Gastric cancer (GC) is among the most frequent types of cancer worldwide. Therefore, understanding the biology of GC tumorigenesis is important for appropriate diagnosis and patient surveillance. The miR-191/425 cluster has been reported to be overexpressed in various human cancers, but the tumorigenic role and clinical significance of miR-191/425 overexpression in gastric carcinogenesis is currently undefined. In this study, the expression of miR-191 and miR-425 in GC tissue and serum was assessed, and the relationship between miRNA expression and clinicopathological data was analyzed. We found that miR-191 and miR-425 were both significantly increased in human GC tissues relative to adjacent normal controls. In addition, miR-191 levels correlated with GC tumor stage and metastatic state. Furthermore, the level of serum miR-191 was significantly higher in the GC group than in the control group when using serum miR-16 as an endogenous control. Finally, inhibition of miR-191 or miR-425 in the GC cell lines HGC-27 not only reduced cell proliferation and cell cycle progression but also impaired cell migration and invasion. Taken together, our results revealed the oncogenic roles of miR-191 and miR-425 in gastric carcinogenesis, and indicated the potential use of serum miR-191 as a novel and stable biomarker for GC diagnosis.
miR-191; miR-425; serum miRNA; gastric cancer
Telomeres protect and cap linear chromosome ends, yet these genomic buffers erode over an organism's lifespan. Short telomeres have been associated with many age-related conditions in humans, and genetic mutations resulting in short telomeres in humans manifest as syndromes of precocious aging. In women, telomere length limits a fertilized egg's capacity to develop into a healthy embryo. Thus, telomere length must be reset with each subsequent generation. Although telomerase is purportedly responsible for restoring telomere DNA, recent studies have elucidated the role of alternative telomeres lengthening mechanisms in the reprogramming of early embryos and stem cells, which we review here.
Heat shock proteins (HSPs) display adjuvant functions when given as fusion proteins to enhance vaccination efficiency. To evaluate enhanced potency of Hantaan virus (HTNV) glycoprotein (GP) and nucleocapsid protein (NP) immunogenicity by heat shock protein 70 (HSP70), a recombinant adenovirus rAd-GnS0.7-pCAG-HSP70C expression vector was developed by genetically linking the HSP70 C-terminal gene (HSP70 359–610 aa, HSP70C) to the Gn and 0.7 kb fragment of the NP (aa1–274-S0.7). C57BL/6 mice were immunized with these recombinant adenoviral vectors. A series of immunological assays determined the immunogenicity of the recombinant adenoviral vectors. The results showed that rAd-GnS0.7-pCAG-HSP70C induced a stronger humoral and cellular immune response than other recombinant adenoviruses (rAd-GnS0.7-pCAG and rAd-GnS0.7) and the HFRS vaccine control. Animal protection experiments showed that rAd-GnS0.7-pCAG-HSP70C was effective at protecting C57BL/6 mice from HTNV infection. The results of the immunological experiments showed that HSP70C lead to enhanced vaccine potency, and suggested significant potential in the development of genetically engineered vaccines against HTNV.
In the failing heart, persistent β-adrenergic receptor (βAR) activation is thought to induce myocyte death by protein kinase A (PKA)-dependent and PKA-independent activation of calcium/calmodulin-dependent kinase II (CaMKII). β-Adrenergic signaling pathways are also capable of activating cardioprotective mechanisms.
This study used a novel PKA inhibitor peptide (PKI) to inhibit PKA activity to test the hypothesis that βAR signaling causes cell death through PKA-dependent pathways and cardioprotection through PKA-independent pathways.
Methods and Results
In PKI transgenic mice, chronic isoproterenol (ISO) failed to induce cardiac hypertrophy, fibrosis, myocyte apoptosis and depressed cardiac function. In cultured adult feline ventricular myocytes (AFVMs), PKA inhibition protected myocytes from death induced by β1-AR agonists by preventing cytosolic and SR Ca2+ overload and CaMKII activation. PKA inhibition revealed a cardioprotective role of β-adrenergic signaling via cAMP/EPAC /Rap1/Rac/ERK pathway. Selective PKA inhibition causes protection in the heart after myocardial infarction (MI) that was superior to β-blocker therapy.
These results suggest that selective block of PKA could be a novel heart failure therapy.
Apoptosis; Ca2+/dependent protein kinase II; ERK2; EPAC
MicroRNAs act as posttranscriptional regulators of gene expression in many biological processes. Their deregulations occur commonly in gastric cancer (GC). Although DNA methylation constitutes an important mechanism for microRNA deregulation in cancer, this field largely remains unexplored.
Total RNA was extracted from the tissues of 100 patients with GC and four gastric cancer cell lines. The expression levels of miR-10a were determined by real-time PCR with specific TaqMan probes. Moreover, a functional analysis of miR-10a in regulating cell proliferation, migration and invasion was performed. Subsequently, quantitative methylation-specific PCR (qMSP) was used to detect the DNA methylation status in the CpG islands upstream of miR-10a. In this study, we found that the expression of miR-10a in GC cells was lower than that in normal cells, which was due to the hypermethylation of the CpG islands upstream of miR-10a. We also validated the slightly lower expression of miR-10a in GC tissues than their adjacent non-neoplastic tissues in 100 GC patients and confirmed the hypermethylation of CpG islands upstream of miR-10a in some patients. Furthermore, re-introduction of miR-10a into GC cells was able to inhibit cell proliferation, migration and invasion. Bioinformatic and immunoblot analysis indicated that the tumor suppressor roles of miR-10a in GC cells were possibly through targeting HOXA1.
Our data indicate that miR-10a acts as a tumor suppressor in GC cells and is partially silenced by DNA hypermethylation in GC, suggesting that miR-10a may serve as a potential diagnostic or therapeutic target of GC.
It has become increasingly clear that the current taxonomy of clinical phenotypes is mixed with molecular heterogeneity, which potentially affects the treatment effect for involved patients. Defining the hidden molecular-distinct diseases using modern large-scale genomic approaches is therefore useful for refining clinical practice and improving intervention strategies. Given that microRNA expression profiling has provided a powerful way to dissect hidden genetic heterogeneity for complex diseases, the aim of the study was to develop a bioinformatics approach that identifies microRNA features leading to the hidden subtyping of complex clinical phenotypes. The basic strategy of the proposed method was to identify optimal miRNA clusters by iteratively partitioning the sample and feature space using the two-ways super-paramagnetic clustering technique. We evaluated the obtained optimal miRNA cluster by determining the consistency of co-expression and the chromosome location among the within-cluster microRNAs, and concluded that the optimal miRNA cluster could lead to a natural partition of disease samples. We applied the proposed method to a publicly available microarray dataset of breast cancer patients that have notoriously heterogeneous phenotypes. We obtained a feature subset of 13 microRNAs that could classify the 71 breast cancer patients into five subtypes with significantly different five-year overall survival rates (45%, 82.4%, 70.6%, 100% and 60% respectively; p = 0.008). By building a multivariate Cox proportional-hazards prediction model for the feature subset, we identified has-miR-146b as one of the most significant predictor (p = 0.045; hazard ratios = 0.39). The proposed algorithm is a promising computational strategy for dissecting hidden genetic heterogeneity for complex diseases, and will be of value for improving cancer diagnosis and treatment.
Epidemiological surveys and animal studies have revealed that inositol metabolism is associated with NTDs, but the mechanisms are not clear. Inositol 1,3,4-trisphosphate 5/6-kinase (ITPK1) is a pivotal regulatory enzyme in inositol metabolic pathway. The objective was to assess the potential impact of the maternal ITPK1 genotypes on the inositol parameter and on the NTD risk in a NTD high-risk area in China.
A case-control study of pregnant women affected with NTDs (n = 200) and controls (n = 320) was carried out. 13 tag SNPs of ITPK1 were selected and genotyped by the Sequenom MassArray system. We found that 4 tag SNPs were statistically significant in spina bifida group (P<0.05). MACH was used to impute the un-genotyped SNPs in ITPK1 locus and showed that 3 meaningful SNPs in the non-coding regions were significant. We also predicted the binding capacity of transcription factors in the positive SNPs using the bioinformatics method and found that only rs3783903 was located in the conserved sequence of activator protein-1 (AP-1). To further study the association between biochemical values and genotypes, maternal plasma inositol hexakisphosphate (IP6) levels were also assessed using LC-MS. The maternal plasma IP6 concentrations in the spina bifida subgroup were 7.1% lower than control (136.67 vs. 147.05 ng mL−1, P<0.05), and significantly lower in rs3783903 GG genotype than others (P<0.05). EMSA showed a different allelic binding capacity of AP-1 in rs3783903, which was affected by an A→G exchange. The RT-PCR suggested the ITPK1 expression was decreased significantly in mutant-type of rs3783903 compared with wild-type in the 60 healthy pregnancies (P<0.05).
These results suggested that the maternal rs3783903 of ITPK1 might be associated with spina bifida, and the allele G of rs3783903 might affect the binding of AP-1 and the decrease of maternal plasma IP6 concentration in this Chinese population.
Behcet’s disease (BD) is a rare and life-long disorder characterized by inflammation of blood vessels throughout the body. BD was originally described in 1937 as a syndrome involving oral and genital ulceration in addition to ocular inflammation. Intestinal BD refers to colonic ulcerative lesions documented by objective measures in patients with BD. Many studies have shown that over 40% of BD patients have gastrointestinal complaints. Symptoms include abdominal pain, diarrhea, nausea, anorexia and abdominal distension. Although gastrointestinal symptoms are common, the demonstration of gastrointestinal ulcers is rare. This so-called intestinal BD accounts for approximately 1% of cases. There is no specific test for BD, and the diagnosis is based on clinical criteria. The manifestations of intestinal BD are similar to those of other colitis conditions such as Crohn’s disease or intestinal tuberculosis, thus, it is challenging for gastroenterologists to accurately diagnose intestinal BD in patients with ileo-colonic ulcers. However, giant ulcers distributed in the esophagus and ileocecal junction with gastrointestinal hemorrhage are rare in intestinal BD. Here, we present a case of untypical intestinal BD. The patient had recurrent aphthous ulceration of the oral mucosa, and esophageal and ileo-colonic ulceration, but no typical extra-intestinal symptoms. During examination, the patient had massive acute lower gastrointestinal bleeding. The patient underwent ileostomy after an emergency right hemicolectomy and partial ileectomy, and was subsequently diagnosed with incomplete-type intestinal BD by pathology. The literature on the evaluation and management of this condition is reviewed.
Intestinal Behcet’s disease; Hemorrhage; Skip ulcers
AIM: To generate a Gpr128 gene knockout mouse model and to investigate its phenotypes and the biological function of the Gpr128 gene.
METHODS: Bacterial artificial chromosome-retrieval methods were used for constructing the targeting vector. Using homologous recombination and microinjection technology, a Gpr128 knockout mouse model on a mixed 129/BL6 background was generated. The mice were genotyped by polymerase chain reaction (PCR) analysis of tail DNA and fed a standard laboratory chow diet. Animals of both sexes were used, and the phenotypes were assessed by histological, biochemical, molecular and physiological analyses. Semi-quantitative reverse transcription-PCR and Northern blotting were used to determine the tissue distribution of Gpr128 mRNA. Beginning at the age of 4 wk, body weights were recorded every 4 wk. Food, feces, blood and organ samples were collected to analyze food consumption, fecal quantity, organ weight and constituents of the blood and plasma. A Trendelenburg preparation was utilized to examine intestinal motility in wild-type (WT) and Gpr128-/- mice at the age of 8 and 32 wk.
RESULTS: Gpr128 mRNA was highly and exclusively detected in the intestinal tissues. Targeted deletion of Gpr128 in adult mice resulted in reduced body weight gain, and mutant mice exhibited an increased frequency of peristaltic contraction and slow wave potential of the small intestine. The Gpr128+/+ mice gained more weight on average than the Gpr128-/- mice since 24 wk, being 30.81 ± 2.84 g and 25.74 ± 4.50 g, respectively (n = 10, P < 0.01). The frequency of small intestinal peristaltic contraction was increased in Gpr128-/- mice. At the age of 8 wk, the frequency of peristalsis with an intraluminal pressure of 3 cmH2O was 6.6 ± 2.3 peristalsis/15 min in Gpr128-/- intestine (n = 5) vs 2.6 ± 1.7 peristalsis/15 min in WT intestine (n = 5, P < 0.05). At the age of 32 wk, the frequency of peristaltic contraction with an intraluminal pressure of 2 and 3 cmH2O was 4.6 ± 2.3 and 3.1 ± 0.8 peristalsis/15 min in WT mice (n = 8), whereas in Gpr128-/- mice (n = 8) the frequency of contraction was 8.3 ± 3.0 and 7.4 ± 3.1 peristalsis/15 min, respectively (2 cmH2O: P < 0.05 vs WT; 3 cmH2O: P < 0.01 vs WT). The frequency of slow wave potential in Gpr128-/- intestine (35.8 ± 4.3, 36.4 ± 4.2 and 37.1 ± 4.8/min with an intraluminal pressure of 1, 2 and 3 cmH2O, n = 8) was also higher than in WT intestine (30.6 ± 4.2, 31.4 ± 3.9 and 31.9 ± 4.5/min, n = 8, P < 0.05).
CONCLUSION: We have generated a mouse model with a targeted deletion of Gpr128 and found reduced body weight and increased intestinal contraction frequency in this animal model.
G-protein-coupled receptors; Gpr128; Knockout mouse; Weight loss; Intestinal contraction frequency
AIM: To examine the status and clinical significance of anaplastic lymphoma kinase (ALK) gene alterations in hepatocellular carcinoma (HCC) patients.
METHODS: A total of 213 cases of HCC were examined by fluorescent in situ hybridization using dual color break-apart ALK probes for the detection of chromosomal translocation and gene copy number gain. HCC tissue microarrays were constructed, and the correlation between the ALK status and clinicopathological variables was assessed by χ2 test or Fisher’s exact test. Survival analysis was estimated using the Kaplan-Meier approach with a Log-rank test. Univariate and multivariate analyses of clinical variables were performed using the Cox proportional hazards regression model.
RESULTS: ALK gene translocation was not observed in any of the HCC cases included in the present study. ALK gene copy number gain (ALK/CNG) (≥ 4 copies/cell) was detected in 28 (13.15%) of the 213 HCC patients. The 3-year progression-free-survival (PFS) rate for ALK/CNG-positive HCC patients was significantly poorer than ALK/CNG-negative patients (27.3% vs 42.5%, P = 0.048), especially for patients with advanced stage III/IV (0% vs 33.5%, P = 0.007), and patients with grade III disease (24.8% vs 49.9%, P = 0.023). ALK/CNG-positive HCC patients had a significantly poorer prognosis than ALK/CNG-negative patients in the subgroup that was negative for serum hepatitis B virus DNA, with significantly different 3-year overall survival rates (18.2% vs 63.6%, P = 0.021) and PFS rates (18.2% vs 46.9%, P = 0.019). Multivariate Cox proportional hazards regression analysis suggested that ALK/CNG prevalence can predict death in HCC (HR = 1.596; 95%CI: 1.008-2.526, P = 0.046).
CONCLUSION: ALK/CNG, but not translocation of ALK, is present in HCC and may be an unfavorable prognostic predictor.
Anaplastic lymphoma kinase gene; Hepatocellular carcinoma; Prognostic predictor
Methotrexate (MTX) is a key agent for the treatment of childhood acute lymphoblastic leukemia (ALL). Increased MTX plasma concentrations are associated with a higher risk of adverse drug effects. ATP-binding cassette subfamily C member 2 (ABCC2) is important for excretion of MTX and its toxic metabolite. The ABCC2 −24C>T polymorphism (rs717620) reportedly contributes to variability of MTX kinetics. In the present study, we assessed the association between the ABCC2 −24C>T polymorphism and methotrexate (MTX) toxicities in childhood ALL patients treated with high-dose MTX. A total of 112 Han Chinese ALL patients were treated with high-dose MTX according to the ALL-Berlin-Frankfurt-Muenster 2000 protocol. Our results showed that presence of the −24T allele in ABCC2 gene led to significantly higher MTX plasma concentrations at 48 hours after the start of infusion, which would strengthen over repeated MTX infusion. The −24T allele in ABCC2 gene was significantly associated with higher risks of high-grade hematologic (leucopenia, anemia, and thrombocytopenia) and non-hematologic (gastrointestinal and mucosal damage/oral mucositis) MTX toxicities. This study provides the first evidence that the −24T allele in ABCC2 gene is associated with the severity of MTX toxicities, which add fresh insights into clinical application of high-dose MTX and individualization of MTX treatment.
Saracatinib, a highly selective, dual Src/Abl kinase inhibitor, is currently in a phase II clinical trial for the treatment of ovarian cancer. In this study, we investigated the effect of saracatinib on the reversal of multidrug resistance (MDR) induced by ATP-binding cassette (ABC) transporters in vitro and in vivo. Our results showed that saracatinib significantly enhanced the cytotoxicity of ABCB1 substrate drugs in ABCB1 overexpressing HeLa/v200, MCF-7/adr and HEK293/ABCB1 cells, an effect that was stronger than that of gefitinib, whereas it had no effect on the cytotoxicity of the substrates in ABCC1 overexpressing HL-60/adr cells and its parental sensitive cells. Additionally, saracatinib significantly increased the Dox and Rho 123 accumulation in HeLa/v200 and MCF-7/adr cells, while it had no effect on HeLa and MCF-7 cells. Furthermore, saracatinib stimulated the ATPase activity and inhibited photolabeling of ABCB1 with [125I]-iodoarylazidoprazosin in a concentration-dependent manner. In addition, the homology modeling predicted the binding conformation of saracatinib within the large hydrophobic drug-binding cavity of human ABCB1. However, neither the expression level of ABCB1 nor the phosphorylation level of Akt was altered at the reversal concentrations of saracatinib. Importantly, saracatinib significantly enhanced the effect of paclitaxel against ABCB1-overexpressing HeLa/v200 cancer cell xenografts in nude mice. In conclusion, saracatinib reverses ABCB1-mediated MDR in vitro and in vivo by directly inhibiting ABCB1 transport function, without altering ABCB1 expression or AKT phosphorylation. These findings may be helpful to attenuate the effect of MDR by combining saracatinib with other chemotherapeutic drugs in the clinic.
Saracatinib; Src/Abl kinase inhibitor; Multidrug resistance; ATP-binding cassette transporters subfamily B member 1(ABCB1)