Histone deacetylase inhibitor pre-treatment enhances the efficacy of DNA-interacting chemotherapeutic drugs in gastric cancer

BACKGROUND The prognosis of gastric cancer continues to remain poor,and epigenetic drugs like histone deacetylase inhibitors(HDACi)have been envisaged as potential therapeutic agents.Nevertheless,clinical trials are facing issues with toxicity and efficacy against solid tumors,which may be partly due to the lack of patient stratification for effective treatments.To study the need of patient stratification before HDACi treatment,and the efficacy of pre-treatment of HDACi as a chemotherapeutic drug sensitizer.METHODS The expression activity of class 1 HDACs and histone acetylation was examined in human gastric cancer cells and tissues.The potential combinatorial regime of HDACi and chemotherapy drugs was defined on the basis of observed drug binding assays,chromatin remodeling and cell death.RESULTS In the present study,the data suggest that the differential increase in HDAC activity and the expression of class 1 HDACs are associated with hypoacetylation of histone proteins in tumors compared to normal adjacent mucosa tissue samples of gastric cancer.The data highlights for the first time that pretreatment of HDACi results in an increased amount of DNA-bound drugs associated with enhanced histone acetylation,chromatin relaxation and cell cycle arrest.Fraction-affected plots and combination index-based analysis show that pre-HDACi chemo drug combinatorial regimes,including valproic acid with cisplatin or oxaliplatin and trichostatin A with epirubicin,exhibit synergism with maximum cytotoxic potential due to higher cell death at low combined doses in gastric cancer cell lines.CONCLUSION Expression or activity of class 1 HDACs among gastric cancer patients present an effective approach for patient stratification.Furthermore,HDACi therapy in pretreatment regimes is more effective with chemotherapy drugs,and may aid in predicting individual patient prognosis.     

Patient knowledge and expectations for functional recovery after stroke

OBJECTIVE: Understanding the causes and outcomes of stroke is important for stroke survivors and may affect their success in rehabilitation and their risk of recurrent stroke; therefore, this study was performed to assess the knowledge and expectation of functional recovery in stroke patients undergoing acute inpatient rehabilitation. DESIGN: Survey study of 50 consecutive stroke patients undergoing inpatient rehabilitation at a single urban rehabilitation hospital. RESULTS: Forty-six percent of participants were able to correctly identify whether they had sustained a cerebral infarct or hemorrhage. Rehabilitation length of stay was, on average, 1 wk longer than anticipated by patients. Patients overestimated their functional abilities on initial assessment and at discharge compared with staff assessments, with some improvement in accuracy for discharge predictions. Ninety-four percent of participants expected to be discharged home, and most achieved this goal. Although no participant anticipated discharge to a nursing home, 10% of patients were discharged to this location. CONCLUSIONS: Knowledge of stroke and its treatment was limited, and expectations for recovery tended to exceed actual accomplishments. There are significant areas of opportunity for enhanced educational efforts for stroke patients undergoing inpatient rehabilitation.     

Endocrine disrupting chemical Bisphenol A and its potential effects on female health

Background and aimA large number of chemical compounds with endocrine-disrupting activity have been documented. These chemicals are ubiquitous and widely used in many products of our daily lives. Bisphenol A (BPA) is among the most common Endocrine Disrupting Chemical (EDC) that has been used for many years in the manufacture of polycarbonate plastics and epoxy resins. There is growing evidence that exposure to these EDCs poses a possible health risk. This review focuses on the effect of EDCs, in particular, BPA on female reproduction and Polycystic Ovary Syndrome (PCOS), which is the most prevalent endocrine disorder of reproductively aged women.MethodsA relevant literature survey was conducted with Google scholar and Pubmed using several appropriate keywords to select the most relevant studies evaluating the role of endocrine disrupting-chemicals in female reproduction.ResultsThe female menstrual cycle and fertility are very sensitive to hormonal imbalance and alteration in endocrine function during critical times and different stages of lifecycle owing to EDC exposure results in many abnormalities like menstrual irregularities, impaired fertility, PCOS, and Endometriosis among others. BPA is the most extensively studied EDC worldwide and has been strongly associated with female reproductive health.ConclusionEDCs lead to deleterious effects on human health including reproductive health which are of global concern. Exposure to EDCs in early life can elicit disease in adult life and maybe even transgenerational. There is an immediate need to minimize the ill effect of EDCs which can be tackled through the collection of more data to clarify the clinical implications of EDCs.     

Expression of αVβ3 integrin in rat endometrial epithelial cells and its functional role during implantation

The α_Vβ₃ integrin as a marker of endometrial receptivity has been well established in human and other mammalian species; however, its expression is still not known in rats. Our objective was to establish the expression of α_Vβ₃ integrin as a marker of endometrial receptivity in rat and to further prove its role in implantation by function-blocking studies in this species. Immunocytochemical, immunohistochemical and flow-cytometric studies were performed in rat endometrial epithelial cells (EEC) to demonstrate the expression of α_Vβ₃ integrin during non-receptive, pre-receptive and receptive phases of the uterus. Results revealed positive immunocytochemical staining for α_v and β₃ subunits on the surface of EEC of days 4 and 5 p.c. (post-coitum), but the intensity was higher in cells of day 5 p.c. Flow-cytometric study revealed higher level of α_Vβ₃ on day 5 p.c. as compared to day 4 p.c. and non-pregnant animals. Immunohistochemical analysis of uterine tissue also revealed that the α_Vβ₃ expression in LE was higher on day 5 p.c. morning as compared to that observed on day 4 p.c. In addition, the expression of β₃ subunit was not evident in rats receiving ormeloxifene, an agent known to inhibit the uterine receptivity. Immunoblotting experiments also revealed higher expression of uterine β₃ on day 5 p.c. On day 6, expression of β₃ was high in implantation sites than on inter-implantation sites. In immature ovariectomized rats, α_Vβ₃ was up-regulated by progesterone and by a combination of estrogen and progesterone. The expression of α_Vβ₃ was also up-regulated in EEC co-cultured with blastocysts. All the agents used for function-blocking studies showed significant reduction in the number of implantation sites in treated horn as compared to sham control horn. The present study has successfully demonstrated the expression of α_Vβ₃ in rat EEC as a marker of endometrial receptivity and showed that this molecule is indispensable for the process of implantation in this species.     

Novel EGFR-MAPK kinase and ABC transporter inhibitors for HepG2 resistant to Erlotinib

Hepatocellular carcinoma (HCC) is the third-leading cause of cancer death in the world, with outlook for most patients having a 5-year survivability of less than 5%. In a previous study from our laboratory, novel estrone inspired analogs act as epidermal growth factor receptor (EGFR) inhibitors in HepG2 cells. This study focuses on the effect of these analogs on an HCC cell line resistance to Erlotinib. Lead compounds MMA132 and MMA102 showed 13 and 20 µM IC₅₀ values, respectively against HepG2-R resistant to Erlotinib. These compounds showed cell cycle arrest of the G2 phase up to 54%, and inhibited cell migration of HepG2-R cells up to 48 h. Western blot analysis revealed that MMA132 reduced total EGFR content after 48 h, while MMA102 inhibited MEK kinase by 84% after 48 h. Western blot analysis also revealed that multidrug resistance protein 2 (MRP2) is overexpressed in HepG2-R, suggesting that ABC transporters play a likely cause in drug resistance. MMA102 showed significant inhibition of both P-glycoprotein (83%) and ABCG2 (53%), two additional ABC transporters. Additionally, MMA102 and MMA132 were used in a combination therapy with MK571(MRP1/2 inhibitor) and produced IC₅₀ values of 18 and 10 µM, respectively, better than either MMA102/132 or MK571 alone. To validate our findings, we conducted molecular dynamic simulations with MMA102 and MMA132 in MEK, P-glycoprotein, MRP1, and MRP2. Results coincided with biological findings in which MMA102 orientation is favored in both MEK and P-glycoprotein pockets, whereas MMA132 likely binds with MRP2, as likely suggested by the combinatorial study.     

Engineering of Human Pluripotent Stem Cells by AAV-mediated Gene Targeting

Precise genetic manipulation of human pluripotent stem cells will be required to realize their scientific and therapeutic potential. Here, we show that adeno-associated virus (AAV) gene targeting vectors can be used to genetically engineer human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Different types of sequence-specific changes, including the creation and correction of mutations, were introduced into the human HPRT1 and HMGA1 genes (HPRT1 mutations being responsible for Lesch–Nyhan syndrome). Gene targeting occurred at high frequencies in both ESCs and iPSCs, with over 1% of all colony-forming units (CFUs) undergoing targeting in some experiments. AAV vectors could also be used to target genes in human fibroblasts that were subsequently used to derive iPSCs. Accurate and efficient targeting took place with minimal or no cytotoxicity, and most of the gene-targeted stem cells produced were euploid and pluripotent.