Oxidant/antioxidant balance has been suggested as an important factor for initiation and progression of cancer. The objective of this study was to determine changes in the levels of malondialdehyde (MDA), nitric oxide (NO), total cholesterol, triglycerides, LDL-cholesterol, HDL-cholesterol, total antioxidant capacity (TAC), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) activities in serum samples of breast cancer patients (n=30) and healthy subjects (n=100). MDA and NO levels were found to be increased in breast cancer patients compared to the healthy subject group (p<0.05). Total cholesterol and triglycerides were elevated; and HDLcholesterol level was found to be decreased in the cancer patients as compared to the healthy subjects (p<0.05). Compared to the healthy group, both serum TAC levels (p<0.001) and activity of SOD and GSH-Px (p=0.05) were found to be decreased in the breast cancer patients as compared to the healthy controls. Considering the data presented in this study, we suggest that free radicals induce lipid eroxidation and peroxidation of unsaturated fatty acid with decreased activity of enzymatic antioxidants in breast cancer.

Despite being one of the most well-studied transcription factors, the temporal regulation of p53-mediated transcription is not very well understood. Recent data suggest that target specificity of p53-mediated transactivation is achieved by posttranslational modifications of p53. K120 acetylation is a modification critical for recruitment of p53 to proapoptotic targets. Our data reveal that histone deacetylase 5 (HDAC5) binds to p53 and abrogates K120 acetylation, resulting in preferential recruitment of p53 to proarrest and antioxidant targets at early phases of stress. However, upon prolonged genotoxic stress, HDAC5 undergoes nuclear export. Concomitantly, p53 is acetylated at the K120 residue and selectively transactivates proapoptotic target genes, leading to onset of apoptosis. Furthermore, upon genotoxic stress in mice where HDAC5 expression is downregulated, the onset of apoptosis is accelerated in the highly vulnerable tissues. These findings suggest that HDAC5 is a key determinant of p53-mediated cell fate decisions in response to genotoxic stress.

These authors contributed equally to this work.Keywords: cancer, genotoxic stress, miRNA, p53, post-translational modifications Abbreviations: miRNA, microRNA; ROS, reactive oxygen species; UTR, untranslated region p53, the revered savior of genomic integrity, receives signals from diverse stress sensors and strategizes to maintain cellular homeostasis. However, the predominance of p53 overshadows the fact that this herculean task is no one-man show; rather, there is a huge army of regulators that reign over p53 at various levels to avoid an unnecessary surge in its levels and sculpt it dynamically to favor one cellular outcome over another. This governance starts right at the time of p53 translation, which is gated by proteins that bind to p53 mRNA and keep a stringent check on p53 protein levels. The same effect is also achieved by ubiquitylases and deubiquitylases that fine-tune p53 turnover and miRNAs that modulate p53 levels, adding precision to this entire scheme. In addition, extensive covalent modifications and differential protein interactions allow p53 to trigger a tailor-made response for a given circumstance. To magnify the marvel, these various tiers of regulation operate simultaneously and in various combinations. In this review, we have tried to provide a glimpse into this bewildering labyrinth. We believe that further studies will result in a better understanding of p53 regulation and that new insights will help unravel many aspects of cancer biology.Regulation of any cellular pathway is essential to coordinate the heterogeneity and complexity of functions in multicellular organisms. Among the tumor suppressors, decoding the bewildering number of pathways that p53 is involved in has long been the holy grail of scientists. p53 is a master regulator that integrates signals from diverse nodes and thus it is of no surprise that it is the most commonly mutated gene in a huge array of cancers with varied origins. p53 has many weapons at its disposal to combat stress including cell cycle arrest, senescence, apoptosis, autophagy, and metabolic reprogramming. Paradoxically, some of the outcomes of p53 activation are disparate and contradictory, such as cell cycle arrest, which is prosurvival, versus apoptosis and senescence, which are directed toward eliminating irreversibly damaged cells. This indicates that p53 needs to be educated to sense the extent and type of damage and make an appropriate choice of the kind of response it is going to elicit. Extensive research on the regulation of p53 under diverse kinds of stresses including genotoxic stress, starvation, hypoxia, and oncogene activation clearly indicate that p53 protein is regulated at diverse levels, including synthesis, degradation, covalent modifications, subcellular localization, and differential interaction with other proteins. Moreover, all possible permutations and combinations of these are employed to modulate p53 specificity, tissue heterogeneity, and diversity of function. In light of this, we restrict this review to exclusively dis...

Caspase-10 belongs to the class of initiator caspases and is a close homolog of caspase-8. However, the lack of caspase-10 in mice and limited substrate repertoire restricts the understanding of its physiological functions. Here, we report that ATP-citrate lyase (ACLY) is a caspase-10 substrate. Caspase-10 cleaves ACLY at the conserved Asp1026 site under conditions of altered metabolic homeostasis. Cleavage of ACLY abrogates its enzymatic activity and suppresses the generation of acetyl-CoA, which is critical for lipogenesis and histone acetylation. Thus, caspase-10-mediated ACLY cleavage results in reduced intracellular lipid levels and represses GCN5-mediated histone H3 and H4 acetylation. Furthermore, decline in GCN5 activity alters the epigenetic profile, resulting in downregulation of proliferative and metastatic genes. Thus caspase-10 suppresses ACLY-promoted malignant phenotype. These findings expand the substrate repertoire of caspase-10 and highlight its pivotal role in inhibiting tumorigenesis through metabolic and epigenetic mechanisms.

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The present research deals with the development of a hybrid yeast strain with the aim of converting pentose and hexose sugar components of lignocellulosic substrate to bioethanol by fermentation. Different fusant strains were obtained by fusing protoplasts of Saccharomyces cerevisiae and xylose-fermenting yeasts such as Pachysolen tannophilus, Candida shehatae and Pichia stipitis. The fusants were sorted by fluorescent-activated cell sorter and further confirmed by molecular characterization. The fusants were evaluated by fermentation of glucose-xylose mixture and the highest ethanol producing fusant was used for further study to ferment hydrolysates produced by acid pretreatment and enzymatic hydrolysis of cotton gin waste. Among the various fusant and parental strains used under present study, RPR39 was found to be stable and most efficient strain giving maximum ethanol concentration (76.8 ± 0.31 g L(-1)), ethanol productivity (1.06 g L(-1) h(-1)) and ethanol yield (0.458 g g(-1)) by fermentation of glucose-xylose mixture under test conditions. The fusant has also shown encouraging result in fermenting hydrolysates of cotton gin waste with ethanol concentration of 7.08 ± 0.142 g L(-1), ethanol yield of 0.44 g g(-1), productivity of 0.45 g L(-1) h(-1) and biomass yield of 0.40 g g(-1).

Objective: Pediatric irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder with variable response to various therapeutic agents. Psyllium has been proven to be effective in adults; however, there is no study in children. The objective of this study is to evaluate the efficacy of psyllium husk as compared to placebo in pediatric IBS patients. Methods: In this double-blind randomized controlled trial, 43 children were assigned to psyllium arm (Group A) and 38 into placebo arm (Group B). Severity is assessed at baseline and after 4 weeks of treatment using IBS severity scoring scale (IBS-SSS) and classified into mild, moderate, and severe categories. Categorical data was compared with chi-square test and paired categorical variable was compared with McNemer test. Results: Mean ages (±SD; in years) of Groups A and B were 9.87 (2.7) and 9.82 (3.17), respectively, with median duration of illness of 12 months. At baseline, type, severity, and parameters (IBS-SSS) of IBS were equally distributed in 2 groups. There was a significant reduction in median interquartile range (IQR) of total IBS-SSS in psyllium versus placebo [75 (42.5–140) vs 225 (185–270); P < 0.001] at 4 weeks. Similarly 43.9% in Group A versus 9.7% in Group B attained remission [IBS-SSS < 75 (P < 0.0001)]. The mean difference in IBS-SSS between Group A and Group B was −122.85 with risk ratio of 0.64 (95% CI; 0.42–0.83; P= 0.001) and absolute risk reduction of 32% (NNT = 3). Conclusions: Psyllium husk is effective for the therapy of pediatric IBS when compared with placebo in short term.