The hTERT-VNTR2-2nd alleles are involved in genomic stability in gastrointestinal cancer.

BACKGROUND: hTERT contains a high density of minisatellites, of which rare alleles of hTERT-VNTR2-2nd have been reported to be associated with prostate cancer. This shows an association between VNTR and cancer, but this repeat sequence is likely to be associated with genomic instability. Therefore, we investigated the effects of hTERT-VNTR2-2nd on gastrointestinal cancer and the relationship between repeated sequence and chromosome instability. METHODS: A case-control study was performed using DNA from 818 cancer-free controls, 539 cases with gastric cancer, 275 cases with colon cancer and 274 cases with rectal cancer. To determine whether minisatellites affect gene expression, expression levels were examined using TERT-reporter vectors in cell lines. In addition, the length of the hTERT-VNTR2-2nd alleles were determined in blood and cancer tissues from 107 gastric cancers, 112 colon cancers and 76 rectal cancers patients to determine whether the repeat sequence was associated with genomic instability during cancer development. RESULTS: No statistically significant association between hTERT-VNTR2-2nd and risk of gastrointestinal cancer was detected. However, it has been shown that VNTRs inserted into the enhancer region can regulate the expression of TERT in gastrointestinal cancer cells. Moreover, hTERT-VNTR2-2nd was analyzed in matched blood and cancer tissue from patients with gastrointestinal cancer and in seven among 294 subjects, and hTERT-VNTR2-2nd was found to be rearranged. CONCLUSIONS: We suggest that minisatellites are associated with genomic instability in cancer and that the hTERT-VNTRs region may increase hTERT expression in gastrointestinal cancer cells.

Functional screen of MSI2 interactors identifies an essential role for SYNCRIP in myeloid leukemia stem cells.

The identity of the RNA-binding proteins (RBPs) that govern cancer stem cells remains poorly characterized. The MSI2 RBP is a central regulator of translation of cancer stem cell programs. Through proteomic analysis of the MSI2-interacting RBP network and functional shRNA screening, we identified 24 genes required for in vivo leukemia. Syncrip was the most differentially required gene between normal and myeloid leukemia cells. SYNCRIP depletion increased apoptosis and differentiation while delaying leukemogenesis. Gene expression profiling of SYNCRIP-depleted cells demonstrated a loss of the MLL and HOXA9 leukemia stem cell program. SYNCRIP and MSI2 interact indirectly though shared mRNA targets. SYNCRIP maintains HOXA9 translation, and MSI2 or HOXA9 overexpression rescued the effects of SYNCRIP depletion. Altogether, our data identify SYNCRIP as a new RBP that controls the myeloid leukemia stem cell program. We propose that targeting these RBP complexes might provide a novel therapeutic strategy in leukemia.

Association of MUC6-minisatellite variants with susceptibility to rectal carcinoma.

A secreted MUC6 mucin is reported to be expressed highly in the stomach and gall bladder. In previous our study, the five minisatellites were identified and a significant association between MUC6-MS5 alleles and gastric cancer was reported. Because of aberrant MUC6 expression is often found in gastrointestinal diseases, we evaluated a relationship between MUC6-MS5 and susceptibility to colorectal cancers. Case-control study was performed with 1,103 cancer-free controls and 414 rectal cancer cases. A significant association (OR = 2.70) between short rare MUC6-MS5 alleles (7, 9 repeats) and the occurrence of cancer was observed in rectal cancer [95 % confidence interval (CI), 1.12-6.54; p = 0.022]. Furthermore, a comparison by gender showed the differences in the association ratios between rectal cancer and short rare MUC6-MS5 alleles: male, 3.97 (CI: 1.36-11.5; p = 0.006) versus female 0.91 (CI: 0.18-4.75; p = 0.913). We also examined the association according to lymphovascular invasion (LVI). The frequency of LVI positive rectal cancer was increased in short rare allele cases than in the total rectal cases: 16.2 % versus 42.9 %. Therefore, we suggest that the short rare MUC6-MS5 alleles may be related to cancer development in male and these cancer cases may be related the bad prognosis.

Effects of testosterone and 17ß-oestradiol on expression of the G protein-coupled receptor P2Y12 in megakaryocytic DAMI cells.

P2Y12 is an important G protein-coupled receptor that is involved in ADP-induced platelet aggregation, which is essential for normal haemostasis. Gender differences in the incidence of cardiovascular disease have been proposed to be linked to the effects of sex hormones on cardiovascular-related genes. We examined the influences of testosterone and 17ß-oestradiol on P2Y12 gene expression in megakaryocytic DAMI cell line. Altered levels of P2Y12 mRNA, protein and the cAMP-dependent vasodilator-stimulated phosphoprotein-Ser157 (VASP-Ser157) phosphorylation were investigated after treatment with 17ß-oestradioal or testosterone as compared to the control groups. Quantitative real-time PCR revealed that the P2Y12 mRNA levels were increased by testosterone in a dose-dependent manner, whereas 17ß-oestrodiol had no effect on P2Y12 gene expression. Induction of the P2Y12 protein by testosterone was found in Western blots of the proteins isolated from testosterone-treated cells. Testosterone-mediated P2Y12 expression was repressed at both the transcriptional and translational levels by the anti-androgen receptor bicalutamide. Treatment with testosterone also resulted in a decrease in the level of VASP-Ser157 phosphorylation, as compared to the control group. The decrease in the level of VASP-Ser157 phosphorylation was reversed by bicalutamide. These findings suggest a novel pathway for testosterone regulation of P2Y12 expression in a megakaryocytic DAMI cell line. Further studies using primary human megakaryocytes and platelets could be necessary to know the effect of hormones on the P2Y12 expression in circulating platelets.

Short rare MUC6 minisatellites-5 alleles influence susceptibility to gastric carcinoma by regulating gene.

The human MUC6 gene, which is reported to be expressed in the stomach and gall bladder, is clustered on chromosome 11p15.5 with other secreted mucins. In this study, the genomic structure of MUC6 has been analyzed and five VNTR (minisatellites; MS1-MS5) were identified. These minisatellites were analyzed in genomic DNA extracted from 1,103 controls, 470 gastric cancer patients, and multigenerational families. Five novel minisatellites were found to be polymorphic and transmitted through meiosis by Mendelian inheritance in families. We evaluated allelic variation in these minisatellites to determine if such variation affected the susceptibility to gastric cancer. A significant association (odds ratio [OR]=7.08) between short rare MUC6-MS5 alleles and relative risks were observed for gastric cancer (95% confidence interval [CI], 1.43-35.19; P=0.005). To investigate the function of minisatellite alleles of MUC6-MS5, we examined the effects on gene expression from luciferase reporters when inserted with minisatellites. Interestingly, when the shortest allele (7TR) was inserted in the promoter, the expression level decreased over 20-fold (P<0.001) in normal and cancer cell lines. Furthermore, the cancer-specific rare allele (TR8) also showed decreased expression levels in cancer cells. Therefore, we suggest that the short rare MUC6-MS5 alleles may be related to cancer development by the regulation of MUC6 expression.

Predictors of acute kidney injury associated with intravenous colistin treatment.

Colistimethate sodium (CMS) was recently re-introduced into clinical practice as a last resort for the treatment of nosocomial infections caused by multiresistant bacteria. This retrospective cohort study was designed to identify predictors of acute kidney injury (AKI) associated with intravenous (i.v.) CMS treatment. From March 2007 to July 2008, 71 adult patients receiving CMS for > or = 72h were enrolled. AKI was defined using Risk, Injury, Failure, Loss and End-stage kidney disease (RIFLE) criteria according to serum creatinine. The median total dose of CMS was 54.3mg/kg (range 27.5-94.5mg/kg). AKI developed in 38 patients (53.5%). Cox regression analysis based of cumulative CMS dose (mg/kg) identified four independent predictors of AKI: male sex [hazard ratio (HR)=3.55, 95% confidence interval (CI), 1.47-8.55]; concomitant use of a calcineurin inhibitor (HR=6.74, 95% CI 2.49-18.24); hypoalbuminaemia (serum albumin level <2.0g/dL) (HR=6.29, 95% CI 2.04-19.39); and hyperbilirubinaemia (total bilirubin level >5mg/dL) (HR=3.53, 95% CI 1.17-10.71). In conclusion, AKI was a common complication of i.v. CMS treatment. Male sex, concomitant use of calcineurin inhibitors, hypoalbuminaemia and hyperbilirubinaemia were independent predictors of AKI. The effect of AKI on patient outcomes was not determined.

Variants of MUC5B minisatellites and the susceptibility of bladder cancer.

The human MUC5B gene, which is primarily expressed in the tracheobronchial tract, is clustered to chromosome 11p15.5 with three other secreted gel-forming mucins, MUC6, MUC2, and MUC5AC. In this study, we identified seven variable number of tandem repeats (VNTRs; minisatellites) from the entire MUC5B region. Six (MUC5B-MS1, -MS2, -MS3, -MS4, -MS5, and -MS7) of the seven minisatellites evaluated in this study were novel minisatellites, but the MUC5B-MS6 minisatellite was described in a previous study. These minisatellites of MUC5B were analyzed in genomic DNA extracted from controls, cancer patients, and multigenerational families. Three (MUC5B-MS3, -MS6, and -MS7) of the seven minisatellites were found to be polymorphic and transmitted through meiosis following Mendelian inheritance in seven families; therefore, these minisatellite polymorphisms could be useful as markers for paternity mapping and DNA fingerprinting. In addition, we evaluated allelic variation in these minisatellites to determine if such variation affected the susceptibility to various carcinomas. To accomplish this, we conducted a case-control study in which the genomic DNA of 789 cancer-free controls and cancer patients with five types of cancer were compared. A statistically significant association between the long rare MUC5B-MS6 alleles and the occurrence of bladder cancer was identified in the younger group (<60; odds ratio, 4.54; 95% confidence interval, 1.0-20.7; p=0.03). This observation suggests that the long rare MUC5B-MS6 alleles evaluated in this study could be used to identify the risk of bladder cancer.

Minisatellite polymorphisms of the SLC6A19: susceptibility in hypertension.

The SLC6A19 is a human homolog of B(0)AT1 that encodes a neutral amino acid transporter. We examined the distribution of VNTR (variable number of tandem repeats; minisatellites) and conducted polymorphic analysis of SCL6A19 isolated from the genomic DNA of controls and multi-generational families. The SLC6A19 was found to contain seven blocks of minisatellites, 3 of which (SLC6A19-MS1, -MS4, and -MS7) showed polymorphism and were found to be transmitted through meiosis following Mendelian inheritance in seven families. These minisatellite polymorphisms may be useful markers for paternity mapping and DNA fingerprinting. Furthermore, we conducted a case-control study in which genomic DNA from 400 controls and 205 cases with essential hypertension was compared. A statistically significant association was identified between rare SLC6A19-MS7 alleles and the occurrence of hypertension (odds ratio, 7.87; 95% confidence interval, 0.88-70.66; and p=0.028). These findings suggest that the rare SLC6A19-MS7 allele may be a risk factor for hypertension.

IL-12 receptor-mediated upregulation of FasL in human ovarian carcinoma cells.

The expression and functions of IL-12 receptor (IL-12R) in human ovarian carcinoma cell lines have been investigated. Ovarian carcinoma cells express both the IL-12Rbeta1 and the IL-12Rbeta2 subunits. IL-12R crosslinking resulted in phosphorylation of Tyk2, p44 (ERK1) and Akt kinases and activation of STATs 2, 3, 4 and 5. IL-12 induced substantial upregulation of Fas ligand (FasL) surface expression in ovarian carcinoma cells paralleled by an increased ability to induce apoptosis in Jurkat cells and PHA-activated lymphocytes. The induction of surface expression of FasL by IL-12 was not due to upregulation of FasL gene expression, but resulted from downregulation of matrix metalloproteinases (MMPs)-3 and -7 and consequently reduced cleavage of FasL from the cell surface. These findings bring new insights into the significance of IL-12-mediated effects in nonlymphoid cancer cells that might be of importance for improving the design of IL-12-based therapies for ovarian cancer.