Destruction of skeletal muscle extracellular matrix is an important pathological consequence of many diseases involving muscle wasting. However, the underlying mechanisms leading to extracellular matrix breakdown in skeletal muscle tissues remain unknown. Using a microarray approach, we investigated the effect of tumor necrosis factor-related weak inducer of apoptosis (TWEAK), a recently identified muscle-wasting cytokine, on the expression of extracellular proteases in skeletal muscle. Among several other matrix metalloproteinases (MMPs), we found that the expression of MMP-9, a type IV collagenase, was drastically increased in myotubes in response to TWEAK. The level of MMP-9 was also higher in myofibers of TWEAK transgenic mice. TWEAK increased the activation of both classical and alternative nuclear factor-B (NF-B) signaling pathways. Inhibition of NF-B activity blocked the TWEAK-induced production of MMP-9 in myotubes. TWEAK also increased the activation of AP-1, and its inhibition attenuated the TWEAK-induced MMP-9 production. Overexpression of a kinase-dead mutant of NF-B-inducing kinase or IB kinase-␤ but not IB kinase-␣ significantly inhibited the TWEAK-induced activation of MMP-9 promoter. The activation of MMP-9 also involved upstream recruitment of TRAF2 and cIAP2 proteins. TWEAK increased the activity of ERK1/2, JNK1, and p38 MAPK. However, the inhibition of only p38 MAPK blocked the TWEAK-induced expression of MMP-9 in myotubes. Furthermore the loss of body and skeletal muscle weights, inflammation, fiber necrosis, and degradation of basement membrane around muscle fibers were significantly attenuated in Mmp9 knock-out mice on chronic administration of TWEAK protein.The study unveils a novel mechanism of skeletal muscle tissue destruction in pathological conditions.

from North India. The GSTT1 and GSTM1 null genotypes were identified by multiplex polymerase chain reaction (PCR) in peripheral blood DNA samples, and GSTP1-313 A/G polymorphism was determined by PCR/ restriction fragment length polymorphism. RESULTSThere was a significant association in null alleles of the GSTM1 (odds ratio 2.239, 95% confidence interval 1.37-3.65, P = 0.001) and GSTT1 (1.891, 1.089-3.282, P = 0.026) with prostate cancer risk, and in the -313 G alleles (Val) of the GSTP1 gene (2.48, 1.51-4.08, P < 0.001). The combined analysis of these three genotypes showed a further increase in the risks of prostate cancer (7.23, 2.42-22.6, P < 0.001). CONCLUSIONThe GSTP1-313 G polymorphism, and null alleles of GSTM1 and GSTT1, are strong predisposing risk factors for sporadic prostate cancer in North India.

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Reactive oxygen species and other free radicals are known to be the mediators of phenotypic and genotypic changes that lead from mutation to neoplasia. There are some primary antioxidants such as glutathione peroxidase (GPx), glutathione S-transferases (GSTs) and reduced glutathione, which protect against cellular and molecular damage caused by the reactive oxygen metabolites (ROMs). The present study was conducted to determine the level of malondialdehyde (MDA), as an index of lipid peroxidation, along with the GPx, GSTs activities and level of reduced glutathione in 45 prostate cancer (PC) patients, 55 benign prostate hyperplasia (BPH) patients as compared to the controls. Significant higher levels of MDA and GSTs activities in the serum, (P<0.005) and significant lower levels of reduced GSH concentration and GPx activity in blood haemolysates (P<0.05) of PC and BPH patients were observed as compared to the controls. The relatively higher GSTs activity and low level of reduced GSH may be due to the response of increased reactive oxygen metabolites production in the blood. The higher MDA and lower GPx activities may be inadequate to detoxify high levels of H202 into HzO leading to the formation of the *OH radical followed by MDA. This result hypothesizes that oxidant-antioxidant imbalance may be one of the major factor responsible for the development of prostate cancer and benign prostate hyperplasia.

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Inactivation of dystrophin gene is the primary cause of Duchenne muscular dystrophy in humans and mdx mice. However, the underpinning mechanisms which govern the pathogenesis of dystrophindeficient skeletal muscle remain poorly understood. We have previously reported activation of MAPK, NF-κB, and PI3K/Akt signaling pathways in diaphragm muscle of mdx mice. In this study, using a protein-DNA array-based approach, we have investigated the activation of 345 transcription factors in diaphragm muscle of 6-week old normal and dystrophin-deficient mdx mice. Our data demonstrate increased activation of a number nuclear transcription factors including AP1, HFH-3, PPARα, c.myb BP, ETF, Fra-1/JUN, kBF-A, N-rasBP, lactoferrin BP, Myb(2), EBP40_45, EKLF (1), p53(2), TFEB, Myc-Max; c-Rel; E2, ISRE; NF-kB; Stat1 p84/p91, Antioxident RE, EVI-1, Stat3, AP3, p53, Stat4, AP4, HFH-1, FAST-1, Pax-5, Beta-RE in the diaphragm muscle of mdx mice compared to corresponding normal mice. The level of activation for p53 was highest among all the transcription factors studied. Furthermore, higher activation of p53 in diaphragm muscle of mdx mice was associated with its increased phosphorylation and nuclear translocation. Collectively, our data suggest that the primary deficiency of dystrophin leads to the aberrant activation of nuclear transcription factors which might further contribute to muscle pathogenesis in mdx mice.

BackgroundN-acetyltransferase 2 is phase II metabolizing enzyme that participates in the bioconversion of heterocyclic arylamines into electrophilic nitrenium ions, which are important ultimate carcinogens that are directly implicated in tumor initiation process. This study was conducted to examine; (1) whether the N-acetyltransferase 2 (NAT2) genotype is a risk factor for prostate cancer, (2) to study effect of NAT2 genotype on modifying prostate cancer risk from tobacco use.MethodsThe case control study was undertaken over a period of 28 months and included 130 prostate cancer patients (CaP) and 140 controls. The NAT2 genotypes were identified by PCR-RFLP method in DNA extracted from peripheral blood. Genotype frequencies and the association of genotypes with patients and control groups were assessed by logistic regression model.ResultsWe observed non-significant association of rapid acetylator genotype NAT2 (OR = 1.452, 95% CI: 0.54–1.87, P = 0.136) in prostate cancer patients. However significant association was observed between rapid acetylator genotype NAT2 and CaP tobacco users (OR = 3.43, 95% CI: 1.68–7.02, P-value < 0.001) when compared with controls.ConclusionThe data suggests that the NAT2 rapid acetylator genotypes may play an important role in determining the risk of developing prostate cancer particularly in the tobacco users of north Indian population.

The role of low penetrance genes and environmental factors in the etiology of bladder cancer (CaB) is unclear, but may involve genetic and environmental factors. Most environmental pro-carcinogens require metabolic activation by phase I enzymes (CYP450s), However, phase II enzyme (i.e., microsomal epoxide hydrolase: mEH) is mainly involved in the detoxification of wide variety of endogenous or exogenous carcinogens. Genetic differences in CYP1A1 gene and the mEH gene polymorphisms have been reported to be associated with susceptibility to various cancers. In our case-control study, we assess whether Msp1 polymorphism of CYP1A1 (CYP1A1*2A), and His(113) in exon 3 and Arg(139) in exon 4 of the mEH susceptibility genotypes, tobacco-use and age factors contribute to bladder cancer risk among Indians. A case-control study was conducted in 106 bladder cancer (CaB) patients and 160 age matched controls from similar ethnic background. The CYP1A1*2A and mEH genotypes were determined by polymerase chain reaction/restriction fragment length polymorphism method from DNA extracted from peripheral blood samples. Binary logistic regression model was used for assessing differences in genotype prevalence between patients and the controls. The Arlequin software package was used to compute haplotype frequencies. We observed non-significant association in T/C polymorphism of the CYP1A1 gene (CYP1A1*2A); however, the exon 3 His genotype of the mEH gene polymorphism alone (odds ratio = 2.67, P = 0.001) or in combination with tobacco-users were significantly associated with the risk of bladder cancer. No associations were observed with stage or grade of bladder tumor with these genotypes. In conclusion, our study demonstrated that exon 3 His genotype of the mEH are more prone to the risk of sporadic bladder cancer in North India.