Differential gene expression triggered by highly cytotoxic α-Emitter-immunoconjugates in gastric cancer cells

Immunoconjugates composed of the α-emitter ²¹³Bi and the monoclonal antibody d9MAb specifically target HSC45-M2 gastric cancer cells expressing mutant d9-E-cadherin. These conjugates efficiently killed tumor cells in a nude mouse peritoneal carcinomatosis model. To elucidate the molecular responses of HSC45-M2 cells to α-emitter irradiation, whole genome gene expression profiling was performed. For that purpose HSC45-M2 cells were incubated with lethal doses of ²¹³Bi-d9MAb. RNA was isolated at 6, 24 and 48 h after irradiation, transcribed into cDNA and hybridized to whole genome microarrays. Results of microarray analysis were validated using RTQ-PCR showing correspondence of approximately 90%. Following incubation with ²¹³Bi-d9MAb, 682-1125 genes showed upregulation and 666-1278 genes showed downregulation at one time point, each. Eight genes appeared upregulated and 12 genes downregulated throughout. Molecular functions and biological processes of differentially expressed genes were categorized according to the PANTHER database. Following ²¹³Bi-d9MAb irradiation also a time-dependent shift in terms of overrepresentation of biological processes was observed. Among the genes showing continuous upregulation, COL4A2, NEDD9 and C3 have not been associated with the cellular response to high LET radiation so far. The same holds true for WWP2, RFX3, HIST4H4 and JADE1 that showed continuous downregulation. According to PANTHER, three of the consistently upregulated (ITM2C, FLJ11000, MSMB) and downregulated (HCG9, GAS2L3, FLJ21439) genes, respectively, have not been associated with any biological process or molecular function so far. Thus, these findings revealed interesting new targets for selective elimination of tumor cells and new insights regarding response of tumor cells to α-emitter exposure.     

Hybrid drug delivery system for oropharyngeal,cervical and colorectal cancer – in vitro and in vivo evaluation

The present investigation was designed with the intention to formulate a versatile 5-fluorouracil(5-FU) matrix tablet surpassing issues associated with current conventional chemotherapeutic drug delivery systems. The novel 5-FU matrix tablet fulfills therapeutic needs by engineering matrix tablets utilizing chitosan–sodium alginate interpolyelectrolyte complex (IPEC). IPEC was characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The matrix tablets were formulated utilizing IPEC alone and in combination with chitosan, sodium alginate and sodium deoxycholate as permeation enhancer. Pharmaceutical properties, swelling studies, in vitro dissolution and diffusion studies, mucoadhesive studies and in vivo studies were performed for formulated 5-FU. The selected chitosan–sodium alginate IPEC offers pH independent 5-FU release in comparison to alone or physical mixture of chitosan and sodium alginate. Furthermore, novel matrix tablets demonstrated significantly higher bioadhesive properties with controlled 5-FU release without the initial burst effect and also demonstrated a higher permeation of 5-FU. To conclude, the developed novel 5-FU matrix tablets pave way as an excellent alternative for cancer treatment which could potentially minimize the dose dependent side effects and provide better patient compliance.     

TSH-β gene polymorphism in Saudi patients with thyroid cancer: A case-control study

BackgroundThe role of thyroid-stimulating hormone in the pathogenesis of thyroid cancer is not yet fully explored. This study aimed to evaluate the role of the TSH-β polymorphism in thyroid cancer in a Saudi cohort.MethodsA prospective case-control study was conducted on 507 patients with differentiated thyroid carcinoma and compared them with 560 controls of Saudi origin. The association of two variants, the rs201857310, and rs7530810, in the TSH-β gene with thyroid cancer risk as well as thyroxine dose, were evaluated.ResultsThe rs201857310_A > G [OR: 0.50 (95 % CI: 0.35–0.71); P < 0.0001] was strongly associated with thyroid cancer. The multivariable analysis adjusted the effect of possible confounders (age, sex, body mass index, and smoking). Multivariable analysis elucidated that the rs201857310 maintained its significant association with the disease [OR: 0.47 (95 % CI: 0.32–0.68); P < 0.0001]. There was no significant association between the other rs7530810 variant and the disease. There was no association between any of the variants and the thyroxine dose requirement (P = 0.79 and 0.73).ConclusionsOur findings indicate that the TSH-β gene could have a role in the pathogenesis of differentiated thyroid carcinoma in the Saudi population.     

A comprehensive review on Brigatinib – A wonder drug for targeted cancer therapy in non-small cell lung cancer

The mortality rate in patients suffering from non-small cell lung cancer (NSCLC) is quite high. This type of cancer mainly occurs due to rearrangements in the anaplastic lymphoma kinase (ALK) gene which leads to form an oncogene of fused gene NPM-ALK. Brigatinib is recently approved by FDA in April 2017 as a potent tyrosine kinase inhibitor (TKI) for the NSCLC therapy. In the present scenario, it is no less than a wonder drug because it is indicated for the treatment of advanced stages of metastatic ALK positive NSCLC, a fatal disease to overcome the resistance of various other ALK inhibitors such as crizotinib, ceritinib and alectinib. In addition to ALK, it is also active against multiple types of kinases such as ROS1, Insulin like growth factor-1Receptor and EGFR. It can be synthesized by using N-[2-methoxy-4-[4-(dimethylamino) piperidin-1-yl] aniline] guanidine and 2,4,5-trichloropyrimidine respectively in two different ways. Its structure consists of mainly dimethylphosphine oxide group which is responsible for its pharmacological activity. It is active against various cell lines such as HCC78, H2228, H23, H358, H838, U937, HepG2 and Karpas- 299. Results of ALTA (ALK in Lung Cancer Trial of AP26113) phase ½ trial shows that 90?mg of brigatinib for 7?days and then 180?mg for next days is effective in the treatment of NSCLC. Brigatinib has been shown to have favorable risk benefit profile and is a safer drug than the available cytotoxic chemotherapeutic agents. In comparison to other FDA approved drugs for the same condition, it causes fewer minor adverse reactions which can be easily managed either by changing the dose or by providing good supportive care. This article is intended to provide readers with an overview of chemistry, pharmacokinetic, pharmacodynamic and safety profile of brigatinib, which addresses an unmet medical need.     

HBXIP blocks myosin-ⅡA assembly by phosphorylating and interacting with NMHC-ⅡA in breast cancer metastasis

Tumor metastasis depends on the dynamic balance of the actomyosin cytoskeleton.As a key component of actomyosin filaments,non-muscle myosin-ⅡA disassembly contributes to tumor cell spreading and migration.However,its regulatory mechanism in tumor migration and invasion is poorly understood.Here,we found that oncoprotein hepatitis B X-interacting protein(HBXIP) blocked the myosin-ⅡA assemble state promoting breast cancer cell migration.Mechanistically,mass spectrometry analysis,co-immunoprecipita...     

A positive circuit of VEGF increases Glut-1 expression by increasing HIF-1α gene expression in human retinal endothelial cells

Treatment of human retinal microvascular endothelial cells (HRMECs) with vascular endothelial growth factor 165 (VEGF₁₆₅) increased hypoxia-inducible factor 1α (HIF-1α), VEGF, and glucose transporter 1 (Glut-1) mRNA expression and Glut-1 protein localization to the membrane. In contrast, treatment of human retinal pigment epithelium cells with VEGF₁₆₅ did not induce HIF-1α, VEGF, and Glut-1 gene expression. Microvascular endothelial cells are surrounded by astrocytic end feet in the retina. Astrocyte-derived A-kinase anchor protein 12 overexpression during hypoxia downregulated VEGF secretion, and this conditioned medium reduced VEGF and Glut-1 expression in HRMECs, suggesting that communications between astrocytes and endothelial cells may be the determinants of the blood vessel network. In HRMECs, HIF-1α small interfering RNA transfection blocked the VEGF₁₆₅-mediated increase in VEGF and Glut-1 gene expression. Inhibition of protein kinase C (PKC) with inhibitor GF109203X or with a small interfering RNA targeting PKCζ attenuated the VEGF₁₆₅-induced Glut-1 protein expression and VEGF and Glut-1 mRNA expression. In addition, results of an immunoprecipitation assay imply an interaction between VEGF receptor 2 (VEGFR2) and PKCζ in HRMECs. Therefore, VEGF secretion by hypoxic astrocytes may upregulate HIF-1α gene expression, inducing VEGF and Glut-1 expression via the VEGFR2–PKCζ axis in HRMECs.     

Phospholipase A2 expression in tumours: a target for therapeutic intervention?

Phospholipase A(2) (PLA(2)) enzymes are involved in lipid metabolism and, as such, are central to several cellular processes. The different PLA(2)s identified to date can be classified into three groups: secreted PLA(2) (sPLA(2)), calcium-independent PLA(2) (iPLA(2)) and calcium-dependent cytosolic PLA(2) (cPLA(2)). In addition to their role in cellular signalling, PLA(2)s have been implicated in diverse pathological conditions, including inflammation, tissue repair and cancer. Elevated levels of sPLA(2) and cPLA(2) have been reported in several tumour types. Here, we summarize the current views on the PLA(2)s, and look at their expression, role in human malignancy and potential as targets for anticancer drug development.     

Adenosine A₁ receptors do not play a major role in the regulation of lipogenic gene expression in hepatocytes

Activation of adenosine A? receptors was reported to promote fatty acid synthesis in AML-12 cells, by increasing the expression of SREBP-(1c) (sterol regulatory binding protein 1c) and FAS (fatty acid synthase). Since these findings have important therapeutic implications for the discovery of adenosine A? receptor agonists, further studies were undertaken to determine the expression and functional relevance of adenosine A? receptor in the liver. To that end, we used two classes of distinct adenosine A? receptor agonists: CPA (N?-cyclopentyl-adenosine), a full agonist and GS-9667 (2-{6-[((1R,2R)-2-hydroxycyclopentyl)-amino]purin-9-yl}(4S,5S,2R,3R)-5-[(2-fluorophenylthio)methyl]-oxolane-3,4-diol), a partial agonist. Treatment of AML-12 cells, HepG2 cells and primary human hepatocytes with either CPA or GS-9667 did not increase the gene expression of SREBP-(1c) or FAS. Furthermore, in AML-12 and HepG2 cells, CPA did not antagonize forskolin-stimulated cAMP production, a characteristic of adenosine A? receptor activation, indicating that these cells lack adenosine A? receptor function. Consistent with this finding, adenosine A? receptor gene expression was found to be very low and adenosine A? receptor protein levels were hardly detectable by radioligand binding assays in hepatic cell lines such as AML-12 and HepG2 as well as in both mouse and human liver tissues. Finally, acute treatment with adenosine A? receptor agonist GS-9667 had no significant effect on gene expression of both SREBP-(1c) and FAS in livers of Sprague Dawley rats. Taken together, our data suggest that the expression of adenosine A? receptor is too low to play a major role in the regulation of lipogenic gene expression in hepatocytes.     

Regulation of VDR expression in rat and human intestine and liver – Consequences for CYP3A expression

The vitamin D receptor (VDR) regulates the expression of drug metabolizing enzymes and transporters in intestine and liver, but the regulation of VDR expression in intestine and liver is incompletely understood. We studied the regulation of VDR mRNA expression by ligands for VDR, farnesoid X receptor (FXR), glucocorticoid receptor (GR) and protein kinase C α (PKCα) in rat and human ileum and liver using precision-cut slices. 1,25(OH)₂D₃ induced VDR expression in rat ileum and liver, and human ileum but not in liver. Chenodeoxycholic acid (CDCA), but not lithocholic acid (LCA) and GW4064 induced VDR mRNA expression in rat ileum and liver. The PKCα activator, phorbol-12-myristate-13-acetate (PMA) induced the expression of VDR in the rat liver, and the induction of VDR by 1,25(OH)₂D₃ and CDCA was inhibited by the PKCα inhibitor, bisindolyl maleimide I (Bis I). These results show that the expression of VDR is likely to be regulated by PKC but not by FXR or VDR activation at least in the rat liver. The VDR mediated induction of its target genes CYP3A1 and CYP3A2 by 1,25(OH)₂D₃ or LCA in the rat ileum was strongly reduced in the presence of CDCA despite the higher VDR expression. Thus, CDCA might potentiate the toxicity of LCA by inhibiting its metabolism.     

A study on expression of hMLH1, hMSH2 and PCNA in colorectal adenomas and malignant change type in adenomas

object To explore the effect of hMLHland hMSH2 in carcinogenesis and progression of colorectal carcinoma,and their influences on proliferation in colorectal adenoma and malignant change in adenomas, Methods we investigated the expression of mismatch repair (MMR） gene hMLH1, hMSH2 and proliferation cell nuclear antigen (PCNA)by immunohistochemistry in 63 cases colorectal adenomas,20cases malignant change in adenomas and 20ceses colorectal carcinomas (CBCs). Results The positive rate of hMLH1 and hMSH2 in colorectal adenomas,malignant change in adenomas and CBCs were significantly lower than that in normal mucosa. With increasing dysplasia in adenomas, the expression rate of hMLH1 and hMSH2 protein decreased gradually; The PCNA label index of tumors with overexpression hMSH2 were significantly higher than that of tumors with negative hMSH2 in colorectal malignant change type in adenomas and CRCs. PCNA lable index of tumors with overexpression hMSH2 were significant higher than that of tumors with negative hMSH2 in adenomas with grade Ⅱ, Ⅲ dysplasia. The changes of PCNA label index in colorectal adenomas, malignant change type in adenomas and CBCs were not association with the expression of hMLH1. Conclusion It indicated that the MMB genes mutation and abnormal function of DNA mismatch repair maybe participate in carcinogenesis of CBCs. It is might be an early event in carcinogenesis of CBCs. It suggested that the reduction of proliferating activities in colorectal neoplasms might be related to mutation and defect of MMB gene.     

Drug-induced changes in P450 enzyme expression at the gene expression level: A new dimension to the analysis of drug–drug interactions

Drug–drug interactions (DDIs) caused by direct chemical inhibition of key drug-metabolizing cytochrome P450 enzymes by a co-administered drug have been well documented and well understood. However, many other well-documented DDIs cannot be so readily explained. Recent investigations into drug and other xenobiotic-mediated expression changes of P450 genes have broadened our understanding of drug metabolism and DDI. In order to gain additional information on DDI, we have integrated existing information on drugs that are substrates, inhibitors, or inducers of important drug-metabolizing P450s with new data on drug-mediated expression changes of the same set of cytochrome P450s from a large-scale microarray gene expression database of drug-treated rat tissues. Existing information on substrates and inhibitors has been updated and reorganized into drug–cytochrome P450 matrices in order to facilitate comparative analysis of new information on inducers and suppressors. When examined at the gene expression level, a total of 119 currently marketed drugs from 265 examined were found to be cytochrome P450 inducers, and 83 were found to be suppressors. The value of this new information is illustrated with a more detailed examination of the DDI between PPARα agonists and HMG-CoA reductase inhibitors. This paper proposes that the well-documented, but poorly understood, increase in incidence of rhabdomyolysis when a PPARα agonist is co-administered with a HMG-CoA reductase inhibitor is at least in part the result of PPARα-induced general suppression of drug metabolism enzymes in liver. The authors believe this type of information will provide insights to other poorly understood DDI questions and stimulate further laboratory and clinical investigations on xenobiotic-mediated induction and suppression of drug metabolism.     

Can quantification of faecal occult blood predetermine the need for colonoscopy in patients at risk for non‐syndromic familial colorectal cancer?

BACKGROUND: Patients at risk for non-syndromic (Lynch or polyposis) familial colorectal neoplasia undergo colonoscopic surveillance at intervals determined by clinically ascertained protocols. The quantitative immunochemical faecal occult blood test for human haemoglobin is specific and sensitive for significant colorectal neoplasia (cancer or advanced adenomatous polyp). AIM: To determine immunochemical faecal occult blood test efficacy for identifying significant neoplasia in at-risk patients undergoing elective colonoscopy. METHODS: We retrospectively identified consecutive at-risk patients who provided three immunochemical faecal occult blood tests before colonoscopy. Quantitative haemoglobin analysis was performed by the OC-MICRO automated instrument using the 100 ng Hb/mL threshold to determine positivity. RESULTS: In 252 at-risk patients undergoing colonoscopy; five had cancer, 14 an advanced adenoma and 46 a non-advanced adenoma. The immunochemical faecal occult blood test was positive in 31 patients (12.3%). Sensitivity, specificity, positive and negative predictive values for cancer were: 100%, 90%, 16% and 100%, and for all significant neoplasia: 74%, 93%, 45% and 98%. With 88% fewer colonoscopies, all colorectal cancers and 74% of all significant neoplasia would have been identified by this one-time immunochemical faecal occult blood test screening. CONCLUSIONS: A sensitive, non-invasive, interval screening test might be useful to predetermine the need for colonoscopy in this at-risk population and minimize unnecessary examinations. This favourable retrospective evaluation will be extended to a prospective study.     

A case of human polyomavirus Bk infection in a patient affected by late stage prostate cancer: could viral infection be correlated with cancer progression?

The basic molecular mechanisms regulating prostate cancer (PCA) development and progression are very poorly understood. Different tumor suppressor genes are implicated in PCA. In particular, since the mutation rate of the p53 gene is also low, researchers have speculated that an infectious agent might play an important role in PCA. Polyomaviruses are candidates for this agent. We selected a patient with a diagnosis of PCA and underwent radical prostatectomy, to investigate the presence of polyomavirus BK (BKV) sequences (urine and neoplastic tissues) and the mutation pattern of p53 gene. The results obtained showed the presence of BKV DNA and of p53 gene mutations in exons 6, 8 and 9. We speculate that BKV might contribute to cellular transformation process, triggered possibly by p53 gene mutations.     

Preliminary evaluation of gene expression profiles in liver of mice exposed to Taihu Lake drinking water for 90 days

Differential gene expression profiling was performed via DNA microarray in the liver tissue of Mus musculus mice after exposure to drinking water of Taihu Lake for 90 days. A total of 75 differentially expressed candidate genes (DEGs) were identified (1.5-fold, p ≤ 0.05), among which the expression of 29 genes was up-regulated and that of 46 genes was down-regulated. Most DEGs were involved in biological process based on gene ontology mapping analysis. The drinking water of Taihu Lake significantly influenced the expression of genes related to cell proliferation, apoptosis, amino acid metabolism, development and immune responses. Long-term exposure to the Taihu drinking water may result in increased carcinogenic risk.     

Withaferin A modulates the Spindle Assembly Checkpoint by degradation of Mad2–Cdc20 complex in colorectal cancer cell lines

Withania somnifera L. Dunal (Ashwagandha) is used over centuries in the ayurvedic medicines in India. Withaferin A, a withanolide, is the major compound present in leaf extract of the plant which shows anticancer activity against leukemia, breast cancer and colorectal cancer. It arrests the ovarian cancer cells in the G2/M phase in dose dependent manner. In the current study we show the effect of Withaferin A on cell cycle regulation of colorectal cancer cell lines HCT116 and SW480 and its effect on cell fate. Treatment of these cells with this compound leads to apoptosis in a dose dependent manner. It causes the G2/M arrest in both the cell lines. We show that Withaferin A (WA) causes mitotic delay by blocking Spindle assembly checkpoint (SAC) function. Apoptosis induced by Withaferin A is associated with proteasomal degradation of Mad2 and Cdc20, an important constituent of the Spindle Checkpoint Complex. Further overexpression of Mad2 partially rescues the deleterious effect of WA by restoring proper anaphase initiation and keeping more number of cells viable. We hypothesize that Withaferin A kills cancer cells by delaying the mitotic exit followed by inducing chromosome instability.     

Plasma rich in quercetin metabolites induces G2/M arrest by upregulating PPAR-γ expression in human A549 lung cancer cells

In this study, we incubated human A549 lung cancer cells with quercetin-metabolite-enriched plasma (QMP) obtained from Mongolian gerbils 2 h after quercetin feeding (100 mg/kg body wt/week). We investigated the effects of QMP on the growth of A549 cells and the possible mechanisms for these effects. We found that QMP but not control plasma (CP) reduced the cell growth in A549 cells. QMP led to cell cycle arrest at the G (2)/M phase by downregulating the expression of cdk1 and cyclin B. QMP but not CP or quercetin itself significantly increased PPAR- γ expression (p < 0.05), which was accompanied by an increase of phosphatase and tensin homologue deleted on the chromosome ten level and a decrease of phosphorylation of Akt. Furthermore, quercetin-3-glucuronide and quercetin-3'-sulfate also significantly increased PPAR- γ expression in A549 cells. GW9662, a PPAR- γ antagonist, significantly suppressed the effects of 10 % QMP on cell proliferation and on the expression of cyclin B and cdk1. Taken together, these data suggest that the activation of PPAR- γ plays an important role, at least in part, in the antiproliferative effects of quercetin metabolites.