We characterized the cellular properties of cancer stem-like cells (CSLCs) isolated from immortalized MDA-MB453 human breast cancer cells in culture. We show that although the expression of Octamer-binding transcription factor 4 (OCT4) correlates to stemness in these CSLCs, OCT4 knockdown does not induce their differentiation. Our results suggest that the differentiation program in MDA-MB453 CSLCs is blocked at a step upstream of the transcription of the OCT4 promoter, allowing CSLCs to maintain their population through asymmetric cell division during many repeated passages. Comparative expression analysis indicates that only a subset of genes and signaling pathways known to be associated with survival and maintenance of CSCs are selectively expressed in CSLCs, as compared with non-CSLCs fractionated from the same parental MDA-MB453 cells. These results suggest that selective expression of a limited number of genes may be sufficient for establishment and maintenance of CSLCs with high tumorigenicity.
The oncogenic potential of colony stimulating factor 1 receptor (CSF-1R) has been well described, while its relevance for human acute myelogenous leukemia (AML) is still undetermined. In a recent clinical trial for AML, sunitinib was found to hold potential therapeutic benefit, however, the mechanism for this remains unknown.
Materials and Methods
In this study, we treated three myeloid cell lines, Mono-Mac 1, THP-1, and U937, with sunitinib, and a small-molecule CSF-1R inhibitor (cFMS-I) to test the anticancer effect of such treatment.
Mono-Mac 1 cells had inhibited proliferation and extracellular-signal regulated kinase activity as a result of CSF-1R inhibition and a dose-dependent increase in CSF-1R expression with both sunitinib and cFMS-I.
Our results suggest potential for CSF-1R as an important target of sunitinib or other similar drugs. Future study of CSF-1R may produce more targeted therapeutic approaches and aid in the development of personalized medicine for AML.
AML; M-CSF; CSF-1; CSF-1R; cFMS; leukemia; tyrosine kinase; individualized medicine
To define the potential utility of 20-hydroxyvitamin D3 (20(OH)D3) as a tumorostatic agent, we assessed its in vitro antiproliferative activity and its in vivo toxicity.
Materials and Methods
The antitumor activity of 20(OH)D3 was tested against breast and liver cancer cell lines using colony formation assays. To assess in vivo toxicity, mice were injected with 5–30 μg/kg 20(OH)D3 intraperitoneally each day for 3 weeks. Blood and organ samples were collected for clinical pathology analyses.
20(OH)D3 displays similar tumorostatic activity towards MDA-MB-453 and MCF7 breast carcinomas, and HepG2 hepatocarcinoma, in a dose-dependent manner. This compound is not hypercalcemic, does not cause detectable toxicities in liver, kidney, or blood chemistry in mice at a dose as high as 30 μg/kg. In contrast, both 25(OH)D3 and 1,25(OH)2D3 caused severe hypercalcemia at a dose of 2 μg/kg.
20(OH)D3 possesses high efficacy for inhibiting cancer cell proliferation in vitro and is non-toxic in vivo, supporting its further development as a potential anticancer therapeutic agent.
20-Hydroxyvitamin D3; antiproliferative activity; hypercalcemic effect; colony formation
Human papillomvirus (HPV)-16 is associated with an improved prognosis in a subset of patients with head and neck squamous cell carcinoma (HNSCC). Cervical carcinoma models have also demonstrated that HPV oncoproteins, E6 and E7, can induce VEGF and HIF-1 gene expression. The purpose of this study was to 1) determine the presence of high-risk HPV 16 in patients with HNSCC enrolled in a prospective phase II clinical trial, 2) assess the impact of HPV status on treatment response and survival in this select cohort treated with combined modality therapy, and 3) identify the differences between HIF/VEGF expression in HPV-positive and -negative tumors.
The effect of HPV status on treatment response and outcome was prospectively evaluated in a single-institution phase II clinical trial. Patients had resectable untreated stage III, IV HNSCC of the oral cavity, oropharynx, hyopharynx, or larynryx, and stage II cancer of the base of tongue, hypopharynx, and larynx. All patients received neoadjuvant chemotherapy with two course of docetaxel (T) 60 mg/m2, then a 96-hour infusion of cisplatin (P) 25mg/m2/d, 5-fluorouracil (F) 700 mg/m2/d, and leucovorin (L) 500 mg/m2/d (TPFL). Those with at least a partial response received a third course. Responding patients then underwent surgery including modified lymph node dissection followed by adjuvant radiation or chemoradiation. Patients who progressed during neoadjuvant chemotherapy proceeded directly to surgery. HPV status was determined by conventional PCR in fresh frozen biopsy samples and Taqman PCR assay on formalin-fixed, paraffin-embedded specimens. HIF-1a and VEGF-A expression were assessed by immunohistochemistry (IHC) and quantitative real-time PCR (RT-PCR). Multivariate Cox proportional hazards regression analysis of time to disease progression or death was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for HPV-positive status.
Of the 24 evaluable cases, HPV16 DNA was detected in 14 specimens, 13 of which were oropharyngeal tumors. HPV18 was not detected in any of the specimens. Treatment compliance was similar between both groups. There was no difference in either the response rates seen after NCT (85.7% vs. 90%), or the pathologic complete response rate for surgical patients (38.5% vs. 42.9%) for the HPV-positive and –negative tumors, respectively. After a median follow-up time of 52.9 months, there was a trend toward better progression-free (HR 0.15; p = 0.06) and overall survival (HR 0.14; p = 0.10), but this was not statistically significant. There was no difference in the level of VEGF expression at the protein level, however, in a subset of 13 fresh frozen tissue samples, quantitative RT-PCR revealed a statistically significant increase in VEGF mRNA transcript in the HPV-positive tumors (p < 0.01). No difference was seen for HIF-1a expression.
HPV-positivity portended a better prognosis in patients with oropharyngeal SCC treated with induction chemotherapy and adjuvant radiation in a prospective clinical trial although the benefit did not reach the level of statistical significance due to the small patient number. The level of VEGF mRNA was up-regulated in HPV16-positive tumors possibly by a HIF-1 independent manner.
Zeng Sheng Ping (ZSP) is a traditional herbal remedy used to prevent progression and growth of neoplastic lesions. It has been shown to inhibit Notch2 expression in a murine lung cancer model, leading us to investigate its therapeutic potential in Notch-dependent brain tumors.
Materials and Methods
3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), apoptosis, and quantitative real-time polymerase chain reaction (RT-PCR) analyses were performed in glioma and medulloblastoma cell lines, and morphological analyses in DAOY flank xenografts.
ZSP inhibited brain tumor growth in vitro, in part by apoptotic induction. Down-regulation of the Notch2 receptor, the pathway target Hairy/Enhancer of Split homolog 1 (Hes1), and the stem cell markers Nestin and CD133 was also observed. Reductions in tumor mass and increases in the necrotic fraction of DAOY xenografts in mice treated with oral ZSP were also observed, but these were not significant.
ZSP can block brain tumor growth and the expression of Notch pathway members and stem cell markers in vitro.
ACAPHA; antitumor-B; Zeng Sheng Ping; Notch; medulloblastoma; glioblastoma
Promoter hypermethylation and global hypomethylation in the human genome are hallmarks of most cancers. Detection of aberrant methylation in white blood cells (WBC) has been suggested as a marker for cancer development, but has not been extensively investigated. This study was carried out to determine whether aberrant methylation in WBC DNA can be used as a surrogate biomarker for breast cancer risk.
Patients and Methods
Promoter hypermethylation of 8 tumor suppressor genes (RASSF1A, APC, HIN1, BRCA1, cyclinD1, RARβ, CDH1 and TWIST1) and DNA methylation for three repetitive elements (LINE1, Sat2M1 and AluM2) were analyzed in invasive ductal carcinoma of the breast, paired adjacent normal tissue and WBC from 40 breast cancer patients by the MethyLight assay. Methylation in WBC from 40 controls was also analyzed.
Tumor and adjacent tissues showed frequent hypermethylation for all genes tested, while WBC DNA was rarely hypermethylated. For HIN1, RASSF1A, APC and TWIST1 there was agreement between hypermethylation in tumor and adjacent tissues (P=0.04, P=0.02, P=0.005 and P<0.0001, respectively). DNA methylation for the three repetitive elements was lower in tumor compared to adjacent tissue and WBC DNA. Significant correlations in the methylation of Sat2M1 between tumor and adjacent tissues and WBC DNA were found (P<0.0001 and P=0.046, respectively). There was also a significant difference in methylation of Sat2M1 between cases and controls (P=0.01).
These results suggest that further studies of WBC methylation, including prospective studies, may provide biomarkers of breast cancer risk.
Breast cancer; promoter hypermethylation; genomic methylation; tumor suppressor genes; repetitive elements; WBC DNA
The neuropathic side-effects of trauma, stroke or therapeutic radiation of the brain for life-threatening neoplastic diseases are the result of damage to normal tissues resulting in defects in cognition and memory. Based upon published preclinical data of curcumin activity application of parenteral curcumin formulations may prove to be to be promising chemotherapy for disorders following neuropathic insults. Studies in in vitro and animal models suggest curcumin may be an effective remediative agent for brain damage. The initial steps in curcumin development for clinical applications to neuropathic disorders are formulating it for intravenous administration, determining the formulated product passes the blood–brain barrier and reaches therapeutic amounts in damaged areas in the brain with tolerable safety. Following intravenous administration of liposomal curcumin, polymeric nanocurcumin and polylactic glycolic acid co-polymer (PLGA)–curcumin in rats, these formulations were observed to cross the blood–brain barrier using a sensitive HPLC assay. All three formulations localized in specific sites in the brain without observable adverse events. One hour following intravenous injection of 5 mg/kg nanocurcumin, or 20 mg/kg PLGA–curcumin, or liposomal curcumin, up to 0.5% of the injected material localized in the brain stem, the striatum, and the hippocampus with varied accumulation and clearance rates.
These data indicate that curcumin does localize in putative damaged brain tissues and suggest therapeutic trials be explored with all three formulations in animal models with pre- and post traumatic states.
Intravenous curcumin; blood; brain barrier; post-traumatic sequelae; hippocampus; striatum; brain stem
DNA-damaging drugs constitute standard chemotherapy regimen for advanced colorectal cancer. Here, the interactions between quercetin and 5- fluorouracil (5-FU), etoposide, and camptothecin were examined in cancer cells.
Materials and Methods
HCT116 colorectal or PPC1 prostate cancer cells were treated with quercetin and the drugs. Clonogenicity assays, cell cycle profiles, and expressions of p53, p21, BAX, survivin and cyclin B1 proteins were used to examine the effects of the treatments.
Quercetin synergistically inhibited the clonogenicity of the wild-type cells, but inhibited the cell cycle effects of all the drugs tested. In p53-null cells, the combination of low dose 5-FU with up to 6 μM quercetin promoted clonogenic survival. Treatment of p53-wild-type cells with 50 μM quercetin reduced drug-induced up-regulation of p53, p21 and BAX. The combination of quercetin and the drugs also reduced the levels of cyclin B1 and survivin proteins.
While high doses of quercetin synergize with DNA-damaging agents, the effect of drug combination with quercetin is influenced by the effective doses and the p53 status of the cells.
Polyphenol; 5-FU; drug–diet interaction; cancer therapy; colorectal cancer; prostate cancer
Resistance to gemcitabine is a major obstacle in the treatment of advanced pancreatic cancer. Previous exploration of protein kinase inhibitors demonstrated that blocking transforming growth factor-β (TGFβ) signal enhances the efficacy of gemcitabine in pancreatic cancer cells.
Materials and Methods
We analyzed the cell viability after combinational treatment of TGFβ receptor I (TβRI) inhibitors, SB431542 and SB525334 with gemcitabine in pancreatic cancer cells. In addition, apoptotic cell death and cell migration were measured.
Combination with TβRI inhibitors significantly augmented the cytotoxicity of gemcitabine in both parental and gemcitabine resistant pancreatic cancer cells. SB525334 significantly increased apoptotic cell death in gemcitabine-resistant cells. Treatment of SB525334 also reduced AKT signal pathway, which plays crucial role in gemcitabine resistance. Migration assay also revealed that blocking TβRI reduces cell migration.
Chemotherapeutic approaches using SB525334 might enhance the treatment benefit of the gemcitabine-containing regimens in the treatment of pancreatic cancer patients.
pancreatic cancer; gemcitabine; transforming growth factor-β receptor (TβR); protein kinase inhibitor; SB525334
We hypothesized that the anticancer activity of cannabinoids was linked to induction of phosphatases.
Materials and Methods
The effects of cannabidiol (CBD) and the synthetic cannabinoid WIN-55,212 (WIN) on LNCaP (prostate) and SW480 (colon) cancer cell proliferation were determined by cell counting; apoptosis was determined by cleavage of poly(ADP)ribose polymerase (PARP) and caspase-3 (Western blots); and phosphatase mRNAs were determined by real-time PCR. The role of phosphatases and cannabinoid receptors in mediating CBD- and WIN-induced apoptosis was determined by inhibition and receptor knockdown.
CBD and WIN inhibited LNCaP and SW480 cell growth and induced mRNA expression of several phosphatases, and the phosphatase inhibitor sodium orthovanadate significantly inhibited cannabinoid-induced PARP cleavage in both cell lines, whereas only CBD-induced apoptosis was CB1 and CB2 receptor-dependent.
Cannabinoid receptor agonists induce phosphatases and phosphatase-dependent apoptosis in cancer cell lines; however, the role of the CB receptor in mediating this response is ligand-dependent.
Cannabinoids; apoptosis; protein tyrosine phosphatases; dual-specificity phosphatases
Chewing of regurgitated food elicits in baboons life-long gastro-esophageal reflux (GER). The acid reflux transforms the multilayered squamous cell epithelium of the esophagus into columnar-lined mucosa with mucus-producing accessory glands. The function of this mucous gland metaplasia (MGM), which mimics Barrett’s mucosa with MGM in humans, is to buffer the gastric acid entering the esophagus during regurgitation. In a previous study of entire esophagi, the majority of baboons showed MGM. The gastric mucosa was not investigated.
Materials and Methods
Hematoxylin-eosin-stained sections from the esophagus, from the lesser gastric curvature and from the greater gastric curvature were collected separately from 50 adult baboons. The presence of MGM was assessed in each one of these locations.
MGM was demonstrated in 92% (46/50) of blocks from the esophagus, in 98% (49/50) of blocks from the lesser curvature and in 90% (45/50) of those of the greater curvature (fundus).
The majority of the animals had MGM, not only in the esophagus but also in the proximal gastric mucosa. Rationally, MGM in baboons starts in the distal esophagus and proceeds downwards, towards the proximal stomach. The histogenesis of the MGM in Barrett’s mucosa in humans (that is Barrett’s mucosa type 2) remains elusive. Therefore the baboon might be an important animal model for studying the histogenesis of Barrett’s mucosa with MGM in humans, a recognized pre-cancerous lesion.
Esophagus; baboon; gastric reflux; mucus metaplasia
In humans and in baboons, protracted gastro-esophageal reflux (GER) transforms the squamous-lined esophagus into columnar-lined (that is Barrett's mucosa, BM). Alcian blue stain (AB) is used to evidence sialomucin-producing goblet cells in human BM.
To assess the frequency and distribution of sialomucin-producing cells in BM in baboons.
Materials and Methods
Sections from 137 consecutive baboon esophagi were alternatively stained with hematoxylin-eosin (H&E) and with AB (pH 2.5), without counterstain.
Out of 137 baboons, 131 (95.6%) had BM. Columnar and intramucosal glandular cells produced sialomucin in all 131 of these animals. Many BM cells were ballooned and filled with sialomucins, despite goblet cells not being found in H&E sections.
In humans, protracted GER is a disease requiring medication that may lead to BM; AB stains mainly goblet cells and occasional columnar cells in BM. In baboons, in contrast, BM is a natural postnatal process of adaptation to GER, triggered by regurgitation and rumination. AB stains all columnar and intra-mucosal glandular cells. Sialomucin-overstuffed cells were more frequent and larger in baboons than in humans. The extra load of sialomucin in BM might be an integrated part of the postnatal life-long process of adaptation to regurgitation and rumination in baboons.
Esophagus; baboons; glandular metaplasia; sialomucins
Wilson's disease is caused by a genetic defect in P-type Cu2+-ATPase (Atp7b), resulting in Cu2+ accumulation in the liver, toxicity, and hepatocellular carcinoma. Exposure of HepG2 cells, and livers of Atp7b mutant mice to toxic Cu2+ resulted in oxidation, (KGDH) and (PDH) enzyme inhibition, and death that was attenuated by thiamine.
Materials and Methods
The effect of oral thiamine supplementation (2%) on hepatocellular carcinoma induced by Cu2+ accumulation in the livers of Atp7b animals at 4, 6, 9, 12, 16, and 21 months was demonstrated using gross morphology and multi-nucleate analysis.
By 16 months of age, untreated Atp7b animals became moribund, their livers were >180% the weight of controls and >75% of their liver was cancerous. At 16 months the livers of thiamine treated Atp7b mice were <130% the weight of controls and <30% cancerous, and at 21 months the mice were still active. However thiamine was ineffective in a subcutaneous xenograft model.
This study suggests that thiamine may constitute a prophylactic for Wilson's disease-induced hepatocellular carcinoma.
Reactive oxygen species; pyruvate dehydrogenase; Long Evans Cinnamon; copper overload
The marine natural product (+)-spongistatin 1 is an extremely potent growth inhibitory agent having activity against a wide variety of cancer cell lines, while exhibiting low cytotoxicity against quiescent human fibroblasts. Consistent with a microtubule-targeting mechanism of action, (+)-spongistatin 1 causes mitotic arrest in DU145 human prostate cancer cells. More importantly, (+)-spongistatin 1 exhibits significant in vivo antitumor activity in the LOX-IMVI human melanoma xenograft model. (+)-Spongistatin 1 is thus an important class of microtubule targeting anticancer agent that warrants further investigation.
(+)-Spongistatin 1; anticancer; natural product; mitosis; xenograft model Xu et al. Anticancer Activity of (+)-Spongistatin 1
Breast cancer cells frequently metastasize to bone, where they up-regulate their expression of the transcription factor GLI2 and the downstream osteolytic factor parathyroid hormone-related protein (PTHrP). The guanosine nucleotide 6-thioguanine (6-TG) inhibits PTHrP expression and blocks osteolytic bone destruction in mice inoculated with bone metastatic cells; however, the mechanism by which 6-TG inhibits PTHrP remains unclear. We hypothesized that 6-TG inhibition of PTHrP is mediated through GLI2 signaling.
Materials and Methods
Human MDA-MB-231 breast cancer cells and RWGT2 squamous-cell lung carcinoma cells were treated with 100 μM 6-TG and examined for GLI2 mRNA expression and stability by Q-PCR, promoter activity by luciferase assay, and protein expression by Western blot.
6-TG significantly blocked GLI2 mRNA and protein expression, but did not affect stability. Additionally, 6-TG directly inhibited GLI2 promoter activity, and when cells were transfected with constitutively expressed GLI2, the inhibitory effect of 6-TG on PTHrP expression was abolished.
Taken together, these data indicate that 6-TG regulates PTHrP in part through GLI2 transcription, and therefore the clinical use of 6-TG or other guanosine nucleotides may be a viable therapeutic option in tumor types expressing elevated levels of GLI proteins.
GLI2; PTHrP; osteolysis; breast cancer; 6-thioguanine
Erythropoietin (EPO) was shown to reduce tumor survival in recent trials, however, its mechanisms of action are unclear. Efforts to measure tumor EPO receptor (EPOR) are limited by the promiscuity of EPOR antibodies, and concerns as to whether EPOR mRNA measurements are confounded by heterogeneity of tumor vasculature, a known EPOR source.
Materials and Methods
This study compared mRNA levels of EPOR and JAK2 in 11 breast tumor epithelial versus endothelial dissections.
In nine tumors EPOR mRNA was 2.6 (1.2–5.7)-fold lower in the epithelial fraction, however, this reduction was less than the reduction of endothelial markers. In two tumors, EPOR mRNA was 2.9 (1.7–4.0)-fold higher in the epithelial fraction. The inter-tumor variation in EPOR levels exceeded the intra-tumor variation between fractions. Similar results were obtained for JAK2.
Tumor vasculature is not the sole source of EPOR and JAK2, and tumors can be segregated by EPOR and JAK2 levels for correlative analysis with clinical outcomes.
Erythropoietin; breast cancer; erythropoietin receptor; erythropoiesis stimulating agents
Intramuscular administration of plasmid DNA vaccines is one of the main delivery approaches that can generate antigen specific T cell responses. However, major limitations of the intramuscular delivery strategy are the low level of myocyte transfection, resulting in a minimal level of protein expression; the inability to directly target antigen presenting cells, in particular dendritic cells, which are critical for establishment of efficacious antigen-specific immune responses. Although several viral vectors have been designed to improve plasmid DNA delivery, they have limitations, including the generation of neutralizing antibodies in addition to lacking the simplicity and versatility required for universal clinical application. We have developed an inexpensive non-viral delivery vector based on the polysaccharide polymer poly-N-acetyl glucosamine with the capability to target dendritic cells. This vector is fully biocompatible, biodegradable, and nontoxic. The advantage of the application of this delivery system relative to other approaches is discussed.
Cytokines; IL-12; paracrine treatment; Schistosoma mansoni; SWAP; systemic treatment; vaccination
In human breast cancer, a growth status switched from estrogen-dependent to growth factor-dependent is a critical step during development of acquired tamoxifen resistance. However, the molecular mechanisms underlying this switch remain poorly understood. The Wilms' tumor suppressor gene, WT1, encodes a zinc-finger protein WT1 that functions as a transcription regulator. High levels of the WT1 expression have been associated with de novo tamoxifen resistance. The goal of this study was to investigate the function of WT1 in acquired tamoxifen resistance.
Materials and Methods
A stable tamoxifen-resistance cell line MCF7TAM was established by selecting ER-positive breast cancer MCF7 cells in a medium containing tamoxifen. Western blot, cell growth assay and shRNA method were used to examine the role of WT1 in acquired tamoxifen resistance.
MCF7TAM cells expressed EGFR, HER2 and WT1 at higher levels compared to tamoxifen-sensitive parental MCF7 cells. MCF7TAM cells responded weakly to estrogen stimulation, grew rapidly in the absence of estrogen and were insensitive to tamoxifen. We also established stable cell lines from MCF7TAM cells to express shRNA specific for WT1, and found expression levels of the epidermal growth factor receptor (EGFR), HER2 and estrogen receptor (ER)-α to be down-regulated in MCF7TAM cells with knocked-down levels of WT1 expression. MCF7TAM cells with WT1 expression knocked-down by shRNA still retained tamoxifen insensitivity.
Our results indicated that WT1 is involved in expressional regulation of the EGFR family members and ER-α during development of acquired tamoxifen resistance.
WT1; HER2; EGFR; estrogen and antiestrogen; breast cancer
Nuclear expression of the cell cycle inhibitor p27KIP1 is reduced in a variety of human malignancies, including breast cancer. Loss of nuclear p27KIP1 during tumor progression, documented by immunohistochemistry (IHC), has been studied for its potential prognostic implication. We examined by IHC the association between nuclear p27KIP1 expression and hormone receptor status in T1N0M0 breast cancer. Patients and Methods: The correlation between nuclear p27KIP1 expression and estrogen (ER) and progesterone (PR) hormone receptor status was analyzed in 122 human T1N0M0 (68 T1a/b, 54 T1c) breast cancer specimens. All patients were staged as N0 by axillary node dissection. Results: A statistically significant reduction in p27KIP1 expression was observed as tumor size increased from T1a/b (7%) to T1c (22%). The proportion of tumors with low nuclear p27KIP1 expression was higher in the ER-negative/PR-negative group compared to the ER-positive/PR-positive group, but this difference was only statistically significant in the T1a/b subgroup (p=0.0007). Conclusion: Further investigations into causes of p27KIP1 deregulation and their relationship to hormone receptor expression in T1N0M0 breast ductal carcinomas are warranted. Such studies may help identify prognostic, as well as predictive, markers of therapy resistance.
p27; breast cancer; node dissection; stage I; estrogen receptor; progesterone receptor
Coumarin and their derivatives are important and useful compounds with diverse pharmacological properties. In the present study, we evaluated the in vitro cytotoxic activity of new acetoxycoumarin derivatives: 4-(7-methoxy-4-methyl-2-oxo-2H-chromen-3-yl)phenyl acetate (1), 4-(1-methyl-3-oxo-3H-benzo[f]chromen-2-yl)phenyl acetate (2), 4-(6-propionamido-4-methyl-2-oxo-2H-chromen-3-yl)phenyl acetate (3), 4-(7-acetoxy-2-oxo-4-phenyl-2H-chromen-3-yl)phenyl acetate (4), 4-(2-oxo-4-phenyl-2H-chromen-3-yl)phenyl acetate (5), 4-(6-bromo-2-oxo-4-phenyl-2H-chromen-3-yl)phenyl acetate (6), 4-(7-(diethylamino)-4-methyl-2-oxo-2H-chromen-3-yl)phenyl acetate (7), 4-(6,8-dibromo-4-methyl-2-oxo-2H-chromen-3-yl)phenyl acetate (8) against A549 human lung cancer, CRL 1548 rat liver cancer and CRL 1439 normal rat liver cells.
Materials and Methods
The cytotoxic activity was evaluated by crystal violet dye-binding assay. The effect of compounds 5 and 7 on different phases of the cell cycle was determined using flow cytometry.
In the A549 lung cancer cell line, the 50% lethal dose (LD50) values for compounds 1–4, 6 and 8 were found to be >100 μM while those for 5 and 7 were 89.3 and 48.1 μM, respectively after 48 h treatment. In the CRL 1548 liver cancer cell line, only compound 7 showed toxicity, with an LD50 of 45.1 μM. Compounds 5 and 7 caused different cell phase arrest in lung and liver cancer cell lines.
The results indicate that 4-(7-(diethylamino)-4-methyl-2-oxo-2H-chromen-3-yl)phenyl acetate (7) had the highest cytotoxic activity in all of the examined cell lines.
Acetoxycoumarins; cell viability; cell cycle; lethal dose
Many recent studies suggest the immune system plays a significant role in the pathogenesis of autoimmune diseases, chronic inflammatory diseases, and cancer.
Materials and Methods
Literature published between 2001 and 2011 was reviewed for risk of cancer development in patients with autoimmune and chronic inflammatory diseases. Mode of risk assessment employed did not limit inclusion of studies. Autoimmune conditions developing after diagnosis of a pre-existing cancer were also considered.
We report a pervasive, largely positive association between 23 autoimmune and inflammatory diseases and subsequent cancer development. We discuss associations for celiac disease, inflammatory bowel disease rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis in detail. We also address the less frequently reported development of some autoimmune conditions within the course of some malignancies, such as vitiligo developing in the course of melanoma.
Evidence demonstrates that chronic inflammation and autoimmunity are associated with the development of malignancy. Additionally, patients with a primary malignancy may develop autoimmune like disease. These relationships imply a need for surveillance of patients on immunomodulatory therapies for potential secondary disease processes.
Autoimmunity; cancer immunity; inflammation; paraneoplastic disease; celiac disease; rheumatoid arthritis; systemic lupus erythematosus; multiple sclerosis; review
Rho kinase (ROCK) proteins are Rho-GTPase activated serine/threonine kinases that function as modulators of actin-myosin cytoskeletal dynamics via regulation of Lin11, Isl-1 & Mec-3 domain (LIM) kinase, myosin light chain (MLC), and MLC phosphatase. A strong correlation between cytoskeletal rearrangements and tumor cell invasion, metastasis, and deregulated microenvironment interaction has been reported in the literature, and the utilization of pharmacological inhibitors of ROCK signaling for the treatment of cancer is actively being pursued by a number of pharmaceutical companies. Indeed, in many preclinical models ROCK inhibitors have shown remarkable efficacy in reducing tumor growth and metastasis. Interestingly, ROCK signaling has been shown to be either pro-apoptotic or pro-survival in a cell type and context dependent manner, though the molecular mechanisms controlling ROCK-mediated cell fate decisions are unknown. This review summarizes the many pleiotropic roles of ROCK signaling in survival and apoptosis, and suggests that controlled modulation of ROCK activity in tumor cells has the potential to significantly affect tumor survival and patient outcome.
ROCK; Rho kinase; ROCK signaling; ROCK pathways; review
Motility of endothelial cells is a requirement for the vascularization of solid malignancies. While tumors have been shown to produce a host of angiogenic factors, including TGF-β, the mechanisms by which such factors regulate endothelial cell motility have not yet been defined. Thus, the role of the serine/threonine phosphatase PP-1 in regulating endothelial cell motility and cytoskeletal architecture was studied. The present study demonstrated that TGF-β stimulation of motility is dependent on PP-1. Likewise, TGF-β was shown to up-regulate paxillin expression through a process that was PP-1 dependent. The interplay between PP-1 and TGF-β was further observed by the induction of cell rounding and the loss of paxillin-actin co precipitations upon PP-1 inhibition and the compensation for these effects by TGF-β. Studies initiated to determine how PP-1 might regulate motility showed its role in maintaining cytoskeletal organization and its capacity to directly dephosphorylate the focal adhesion scaffolding protein paxillin. These studies suggest that the interplay between TGF-β and PP-1 regulates the motility of endothelial cells that is critical to the process of angiogenesis.
Cytoskeleton; paxillin; phosphatase; PP-1; TGF-β; motility; endothelial cells
Prostate cancer is one of the most commonly diagnosed solid malignancies among US men. We identified gallic acid (GA) as a major bioactive cytotoxic constituent of a polyherbal Ayurvedic formulation – triphala (TPL). Both TPL and GA were evaluated on (AR)+ LNCaP prostate cancer and normal epithelial cells.
Total polyphenols in TPL were determined using Folin and Ciocalteu method, followed by GA quantitation by high performance liquid chromatography. Cell toxicity was evaluated by crystal-violet after 24, 48, 72 and 96 h.
TPL contains 40% unidentified polyphenolic acids, of which 2.4% comprised GA. GA induced severe morphological alterations and was about 3-fold more cytotoxic towards cancer cells than TPL. This activity increased further in presence of dihydrotestosterone. GA toxicity on normal cells was low at 72 h. Combination of GA with flutamide caused higher toxicity to cancer cells than either of the compounds alone.
GA appears to have promising anticancer activity.
Prostate cancer; cytotoxicity; triphala; gallic acid; Ayurvedic medicine
The molecular mechanisms of triptolide responsible for its antitumor properties are not yet fully understood. The ubiquitin/proteasome system is an important pathway of protein degradation in cells. This study investigated whether triptolide may inhibit proteasomal activity and induce apoptosis in human cancer cells.
Materials and Methods
In vitro proteasome inhibition was measured by incubation of a purified 20S proteasome with triptolide. Human breast and prostate cancer cell lines were also treated with different doses of triptolide for different times, followed by measurement of proteasome inhibition (levels of the chymotrypsin-like activity, ubiquitinated proteins and three well-known proteasome target proteins, p27, IκB-α and Bax) and apoptosis induction (caspase-3 activity and PARP cleavage).
Triptolide did not inhibit the chymotrypsin-like activity of purified 20S proteasome. However, treatment of triptolide was able to cause decreased levels of cellular proteasomal chymotrypsin-like activity and accumulation of ubiquitinated proteins and three well-known proteasome target proteins in human breast and prostate cancer cells, associated with apoptosis induction.
It is possible that at least one of metabolites of triptolide has proteasome-inhibitory activity.
Triptolide; medicinal compounds; proteasome inhibitors; apoptosis; cancer therapy