A technique for fabricating a hollowed nasal stent using a connector of an intravenous infusion set to manage iatrogenic nasal vestibular stenosis in an infant.

The presented technique describes the steps for fabricating a hollow and rigid intranasal stent to maintain the patency of the nasal passage after iatrogenic nasal vestibular stenosis in an infant. The technique uses a connector between the injection bulb or site and the hypodermic needle of an intravenous infusion set to ease the impression making and avoid the additional step of hollowing the stent.

A long-term nutritional assessment of maxillary cancer patients undergoing prosthodontic rehabilitation after surgery: A longitudinal study.

Purpose: To evaluate the nutritional status (NS) of patients planned for maxillectomy and prosthodontic rehabilitation using three nutritional assessment methods. Methods: This longitudinal study enrolled 18 planned maxillectomy patients following the inclusion and exclusion criteria. NS was evaluated at five stages: before surgery (S0), 2 weeks after surgery (S1), 3 months after insertion of intermediate obturator (S2), just before fabrication of definitive obturator (S3), and 3 months after insertion of definitive obturator (S4) using two nutritional assessment tools i.e. Patient Generated -Subjective Global Assessment (PG-SGA) &Nutritional risk index (NRI); and body composition indicators i.e. body mass index (BMI), fat free mass (FFM), total body water (TBW), skeletal muscle mass (SMM) and skeletal muscle mass index (SMMI).To determine the changes in patient's nutritional status among different time points Repeated Measure ANOVA with Bonferroni post hoc adjustments was used. Results: Out of 18 patients, 12 were completed the study. NS of maxillectomy patients deteriorates significantly (p < .05) till stage S2. At S3, significant improvement occurred as compared to stage S2, but it remained significantly less than pre-surgical level. However, at stage S4, all parameters were statistically comparable to S0 (p > .05) except for PG-SGA (p < .001) and SMM (p = .044). Conclusion: NS of maxillectomy patients worsen post surgically due to surgical morbidity and adverse effects of radiotherapy (RT) but improves with post-surgical healing, resolution of sequel of RT and improved oral function due to well-adapted obturator prosthesis.

Influence of socioeconomic status on psychological distress and treatment satisfaction levels among patients undergoing prosthetic rehabilitation following maxillectomy: An observational study.

Aim: The aim of this study was conducted to evaluate the effect of socioeconomic status (SES) on psychological distress and treatment satisfaction levels of patients who underwent maxillectomy and rehabilitation with obturator prosthesis. Settings and Design: Prospective, observational, analytic study. Materials and Methods: Forty-three patients undergoing maxillectomy were enrolled and divided into upper, middle, and lower SES groups, according to the updated Kuppuswamy SES scale. Psychological distress levels were assessed using Hospital Anxiety and Depression Scale (HADS) before maxillectomy (T0) and at 3 weeks after delivery of definitive obturator (T1). Treatment satisfaction levels with obturator prosthesis were assessed using Obturator Functioning Scale (OFS) at T1. HADS and OFS scores were then correlated with the SES of the participants. Results: Out of 43 participants, 7 were lost to follow up. The total number of participants in upper, middle, and lower SES groups was 14, 11, and 11, respectively. Before surgery, there was no significant difference in anxiety levels (P > 0.05) among different SES groups. However, the depression levels were the highest in the lower SES and decreased significantly with increasing SES. Prosthetic rehabilitation led to statistically significant (P < 0.05) fall in the levels of both anxiety and depression assessed at 3 weeks after delivery of prosthesis. The upper SES group was found to be less anxious and depressed compared to middle and lower SES groups after prosthodontic rehabilitation. Treatment satisfaction level was found to be significantly low (P = 0.005) in lower SES group as compared to upper SES group while no difference was found in between the middle SES when compared to higher or lower SES groups. Conclusions: SES has a profound impact on the patient's psychosocial well-being and treatment satisfaction. Patients of lower SES reported with higher psychological distress and lesser treatment satisfaction compared to those belonging to upper SES.

Streamflow modeling and contribution of snow and glacier melt runoff in glacierized Upper Indus Basin.

The Upper Indus Basin has a large concentration of glaciers and mainly fed by snow and glacier melt. These melt runoffs are the primary driver of discharge and significantly contribute to Indus flows. Therefore, the present study was undertaken in the Upper Indus Basin (UIB) up to the Besham Quila site. This study focuses on quantifying runoff's contribution from different sources, including snow and glacier melt, and evaluates model performance in the glacierized Himalayan basin. The model was calibrated (1981-2000) and validated (2001-2007) daily and monthly using 27 years of measured discharge data at the Besham Quila station. A statistical indicator shows a "good" relationship between simulated and observed discharge on a daily and "very good" on a monthly timestamp. In this study, the annual contribution from snow/ice melt in the basin was quantified and found to be 51% of the total runoff. Apart from this, around 30% of water comes from direct runoff generated through liquid precipitation and 3.8% from groundwater. The remaining (~15%) is contributed by interflows sourced from the rainfall and snow/ice melt. The basin receives 61% contribution from snow and glacier melt during monsoon (July-Sept) and 38% during summer (April-June) seasons, while negligible in other seasons. A decreasing trend is observed in modelled total runoff and melt runoff of about 1.11 × 109 m3 a-1 and 0.73 × 109 m3 a-1, respectively.

Comparative stemness and differentiation of luminal and basal breast cancer stem cell type under glutamine-deprivation.

Glutamine (gln) metabolism has emerged as a cancer therapeutic target in past few years, however, the effect of gln-deprivation of bCSCs remains elusive in breast cancer. In this study, effect of glutamine on stemness and differentiation potential of bCSCs isolated from MCF-7 and MDAMB-231 were studied. We have shown that bCSCs differentiate into CD24+ epithelial population under gln-deprivation and demonstrated increased expression of epithelial markers such as e-cadherin, claudin-1 and decreased expression of mesenchymal protein n-cadherin. MCF-7-bCSCs showed a decrease in EpCAMhigh population whereas MDAMB-231-bCSCs increased CD44high population in response to gln-deprivation. The expression of intracellular stem cell markers such sox-2, oct-4 and nanog showed a drastic decrease in gene expression under gln-deprived MDAMB-231-bCSCs. Finally, localization of ß-catenin in MCF-7 and MDAMB-231 cells showed its accumulation in cytosol or perinuclear space reducing its efficiency to transcribe downstream genes. Conclusively, our study demonstrated that gln-deprivation induces differentiation of bCSCs into epithelial subtypes and also reduces stemness of bCSCs mediated by reduced nuclear localization of ß-catenin. It also suggests that basal and luminal bCSCs respond differentially towards changes in extracellular and intracellular gln. This study could significantly affect the gln targeting regimen of breast cancer therapeutics.

Hyaluronic acid induction on breast cancer stem cells unfolds subtype specific variations in stemness and epithelial-to-mesenchymal transition.

The reoccurrence of breast cancer is a major concern due to presence of cancer stem cells (CSCs). Considering the key role of hyaluronic acid (HA) in modulating the inflammation and cellular migration in cancer, the response of high molecular weight (HMW) and low molecular weight (LMW) HA towards various subtypes of breast cancer and breast cancer stem cells remain elusive. The aim of this study is to determine the effect of exogenous HMW-HA and LMW-HA on stemness of CSCs and epithelial-to-mesenchymal transition which may help in designing HA based therapeutic strategies. LMW-HA induces EMT in MCF-7 more prominently as compared to MDA-MB-231. However, HMW-HA did not show significant changes in the expression of EMT genes. Surprisingly, both HMW-HA and LMW-HA have shown to decrease the expression of EpCAM in MCF-7 cells and decrease the expression of CD44 in MDAMB-231 cells. HA has maintained the native stem cells phenotype of bCSCs isolated from MCF-7 only. The bCSCs isolated form MDAMB-231 showed a decrease in CD44. Luminal subtype has shown to follow Wnt/ß-catenin whereas in the basal subtype localization of CD44 from surface to cytosol was observed in response to HA. Our study has demonstrated that bCSCs in luminal and basal cells follow differential intracellular signaling mechanisms in response to HA. This study could significantly influence the therapeutics involving HA in breast cancer.

Advancements in Cancer Stem Cell Isolation and Characterization.

Occurrence of stem cells (CSCs) in cancer is well established in last two decades. These rare cells share several properties including presence of common surface markers, stem cell markers, chemo- and radio- resistance and are highly metastatic in nature; thus, considered as valuable prognostic and therapeutic targets in cancer. However, the studies related to CSCs pave number of issues due to rare cell population and difficulties in their isolation ascribed to common stem cell marker. Various techniques including flow cytometry, laser micro-dissection, fluorescent nanodiamonds and microfluidics are used for the isolation of these rare cells. In this review, we have included the advance strategies adopted for the isolation of CSCs using above mentioned techniques. Furthermore, CSCs are primarily found in the core of the solid tumors and their microenvironment plays an important role in maintenance, self-renewal, division and tumor development. Therefore, in vivo tracking and model development become obligatory for functional studies of CSCs. Fluorescence and bioluminescence tagging has been widely used for transplantation assay and lineage tracking experiments to improve our understanding towards CSCs behaviour in their niche. Techniques such as Magnetic resonance imaging (MRI) and Positron emission tomography (PET) have proved useful for tracking of endogenous CSCs which could be helpful in their identification in clinical settings.

Outcomes of deep anterior lamellar keratoplasty following autologous simple limbal epithelial transplant in pediatric unilateral severe chemical injury.

AIMS: To evaluate outcomes of deep anterior lamellar keratoplasty (DALK) in pediatric eyes with unilateral severe chemical injury which have undergone autologous simple limbal epithelial transplant (SLET). SETTINGS AND DESIGN: The study design was a retrospective case series. MATERIALS AND METHODS: This retrospective, case series of all children <16 years of age that have undergone DALK following autologous SLET procedure in unilateral severe chemical injury evaluates the outcomes and complications in the setting of a tertiary care center in North India. STATISTICAL ANALYSIS USED: Nonparametric data have been expressed as median (range), parametric qualitative data as percentage, and quantitative data as a mean ± standard deviation. Spearman's correlation coefficient is used for finding a correlation between variables. RESULTS: Eleven eyes of 11 children (5 male and 6 female) with a mean age of 8.9 ± 4.7 years underwent DALK following ocular surface reconstruction with autologous SLET earlier for unilateral severe chemical injury with limbal stem cell deficiency. Follow-up ranged from 6 to 18 months (13.00 ± 4.58 months) following DALK procedure. All patients with a minimal follow-up of 6 months were evaluated for visual outcomes. Visual acuity ranged from 0.3 to 3 logMAR units (0.6 ± 0.2 logMAR units). Complications were encountered in three patients. Anatomical success was seen in 72.72% patients and visual success was noted in 54.54% patients. CONCLUSIONS: DALK is a feasible option in children with severe unilateral chemical injury who have undergone ocular surface reconstruction with autologous SLET procedures.

Clinical correlation of imaging findings in congenital cranial dysinnervation disorders involving abducens nerve.

PURPOSE: High-resolution magnetic resonance imaging (MRI) of intracranial parts of sixth nerve and seventh nerve and the extraocular muscles (EOMs) in orbit to correlate the clinical characteristics in patients with two special forms of strabismus in congenital cranial dysinnervation disorders which are Duane's retraction syndrome (DRS) and Mobius syndrome. MATERIALS AND METHODS: Morphological analysis by 3T MRI of orbit (using surface coils) and brain (using 32 channel head coil) was performed on 6 patients with clinical DRS (1 bilateral), 2 cases with Mobius syndrome, and 1 case with congenital sixth nerve palsy. These were compared with findings in five controls. RESULTS: We observed absence/hypoplasia of sixth nerve in five out of seven eyes with DRS (71.42%), anomalous course in one eye, sixth and seventh nerve absence/hypoplasia in affected eyes with Mobius syndrome and bilateral absence/hypoplasia of the sixth nerve in congenital sixth nerve palsy. For EOMs we calculated maximum diameter, area, and circumference of muscles using Osirix software, and noticed significant hypoplasia of lateral rectus in comparison to controls (P < 0.001). CONCLUSIONS: MRI gives useful information regarding confirmation of clinical diagnosis and its neurological anomalies in complex cases and helps to plan tailor made surgical management.

A Possible Role of the Full-Length Nascent Protein in Post-Translational Ribosome Recycling.

Each cycle of translation initiation in bacterial cell requires free 50S and 30S ribosomal subunits originating from the post-translational dissociation of 70S ribosome from the previous cycle. Literature shows stable dissociation of 70S from model post-termination complexes by the concerted action of Ribosome Recycling Factor (RRF) and Elongation Factor G (EF-G) that interact with the rRNA bridge B2a/B2b joining 50S to 30S. In such experimental models, the role of full-length nascent protein was never considered seriously. We observed relatively slow release of full-length nascent protein from 50Sof post translation ribosome, and in that process, its toe prints on the rRNA in vivo and in in vitro translation with E.coli S30 extract. We reported earlier that a number of chemically unfolded proteins like bovine carbonic anhydrase (BCA), lactate dehydrogenase (LDH), malate dehydrogenase (MDH), lysozyme, ovalbumin etc., when added to free 70Sin lieu of the full length nascent proteins, also interact with identical RNA regions of the 23S rRNA. Interestingly the rRNA nucleotides that slow down release of the C-terminus of full-length unfolded protein were found in close proximity to the B2a/B2b bridge. It indicated a potentially important chemical reaction conserved throughout the evolution. Here we set out to probe that conserved role of unfolded protein conformation in splitting the free or post-termination 70S. How both the RRF-EFG dependent and the plausible nascent protein-EFG dependent ribosome recycling pathways might be relevant in bacteria is discussed here.

Regulation of MDA-MB-231 cell proliferation by GSK-3ß involves epigenetic modifications under high glucose conditions.

Hyperglycemia is a critical risk factor for development and progression of breast cancer. We have recently reported that high glucose induces phosphorylation of histone H3 at Ser 10 as well as de-phosphorylation of GSK-3ß at Ser 9 in MDA-MB-231 cells. Here, we elucidate the mechanism underlying hyperglycemia-induced proliferation in MDA-MB-231 breast cancer cells. We provide evidence that hyperglycemia led to increased DNA methylation and DNMT1 expression in MDA-MB-231 cells. High glucose condition led to significant increase in the expression of PCNA, cyclin D1 and decrease in the expression of PTPN 12, p21 and PTEN. It also induced hypermethylation of DNA at the promoter region of PTPN 12, whereas hypomethylation at Vimentin and Snail. Silencing of GSK-3ß by siRNA prevented histone H3 phosphorylation and reduced DNMT1 expression. We show that chromatin obtained after immunoprecipitation with phospho-histone H3 was hypermethylated under high glucose condition, which indicates a cross-talk between DNA methylation and histone H3 phosphorylation. ChIP-qPCR analysis revealed up-regulation of DNMT1 and metastatic genes viz. Vimentin, Snail and MMP-7 by phospho-histone H3, which were down-regulated upon GSK-3ß silencing. To the best of our knowledge, this is the first report which shows that interplay between GSK-3ß activation, histone H3 phosphorylation and DNA methylation directs proliferation of breast cancer cells.

The antiprion compound 6-aminophenanthridine inhibits the protein folding activity of the ribosome by direct competition.

Domain V of the 23S/25S/28S rRNA of the large ribosomal subunit constitutes the active center for the protein folding activity of the ribosome (PFAR). Using in vitro transcribed domain V rRNAs from Escherichia coli and Saccharomyces cerevisiae as the folding modulators and human carbonic anhydrase as a model protein, we demonstrate that PFAR is conserved from prokaryotes to eukaryotes. It was shown previously that 6-aminophenanthridine (6AP), an antiprion compound, inhibits PFAR. Here, using UV cross-linking followed by primer extension, we show that the protein substrates and 6AP interact with a common set of nucleotides on domain V of 23S rRNA. Mutations at the interaction sites decreased PFAR and resulted in loss or change of the binding pattern for both the protein substrates and 6AP. Moreover, kinetic analysis of human carbonic anhydrase refolding showed that 6AP decreased the yield of the refolded protein but did not affect the rate of refolding. Thus, we conclude that 6AP competitively occludes the protein substrates from binding to rRNA and thereby inhibits PFAR. Finally, we propose a scheme clarifying the mechanism by which 6AP inhibits PFAR.

High glucose and insulin differentially modulates proliferation in MCF-7 and MDA-MB-231 cells.

Various preclinical and clinical studies have linked diabetes and breast cancer, but little is known regarding the molecular mechanism involved. This study aimed to investigate the effect of high glucose and insulin in breast cancer cells (MCF-7: non-invasive, hormone dependent, and MDA-MB-231: invasive, hormone independent). In contrast to MCF-7 cells, high glucose augmented proliferation of MDA-MB-231 cells as observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and bromodeoxyuridine assays. The high-glucose condition led to increased expression of cyclin D1, de-phosphorylation of p38, and increased phosphorylation of ERK in MDA-MB-231 cells but not in MCF-7 cells. Interestingly, we observed increased phosphorylation of GSK-3ß, NF-κB, and ERα only in MCF-7 cells, highlighting their role as potential targets in prevention of progression of breast cancer under a high-glucose and insulin condition. Furthermore, insulin treatment under a high-glucose condition resulted in increased histone H3 phosphorylation and de-acetylation only in MDA-MB-231 cells. Taken together, we provide the first evidence that high glucose and insulin promotes proliferation of MDA-MB-231 cells by differential alteration of GSK-3ß, NF-κB, and ERα expression and histone H3 modifications, which may directly or indirectly modulate the expression of genes involved in its proliferation.

Identical RNA-protein interactions in vivo and in vitro and a scheme of folding the newly synthesized proteins by ribosomes.

A distinct three-dimensional shape of rRNA inside the ribosome is required for the peptidyl transfer activity of its peptidyltransferase center (PTC). In contrast, even the in vitro transcribed PTC RNA interacts with unfolded protein(s) at about five sites to let them attain their native states. We found that the same set of conserved nucleotides in the PTC interact identically with nascent and chemically unfolded proteins in vivo and in vitro, respectively. The time course of this interaction, difficult to follow in vivo, was observed in vitro. It suggested nucleation of folding of cytosolic globular proteins vectorially from hydrophilic N to hydrophobic C termini, consistent with our discovery of a regular arrangement of cumulative hydrophobic indices of the peptide segments of cytosolic proteins from N to C termini. Based on this observation, we propose a model here for the nucleation of folding of the nascent protein chain by the PTC.

Differential response to sustained stimulation by hCG & LH on goat ovarian granulosa cells.

BACKGROUND & OBJECTIVES: Chapekar established a model of ovarian tumourigenesis in mice by splenic transplantation of ovaries, resulting in sustained luteinizing hormone (LH) levels because of absence of feedback inhibition. There is increasing evidence of the differential response to LH or hCG under various experimental conditions. The effect of sustained hormonal stimulation in long term cultures is sparsely investigated. The study is aimed to determine the role of hCG and LH stress on caprine ovarian granulosa cells and their downstream signaling in short and long term cultures. METHODS: To study the response of hCG and LH stress and downstream signaling, short term cultures were set up by exposing goat ovarian granulosa cells in primary cultures to hCG and LH stress (levels beyond their physiological doses) for 5 days (P0). Cells were sub-cultured at sixth day and subjected to prolonged LH/ hCG stress for two weeks in passage 1(P1) (long term cultures). Downstream cell signaling molecules were assessed. Intracellular cAMP was estimated by ELISA. For PKA and PKC, activity assays were performed. pERK protein expressions in short term cultures were assessed by Western blot and flowcytometry; in long term cultures, pERK expression was analyzed by flowcytometry. RESULTS: Differential effects on cell proliferation were observed in long term cultures, where the untreated and hCG exposed cells showed markedly reduced cell proliferation after second week of exposure while LH treated cells continued to proliferate. Different levels of cAMP, PKA, PKC and phosphorylated ERK1/2 were observed on short term and long term LH stimulation. On sustained hormonal stimulation, cAMP levels were significantly (P<0.05) higher in hCG treated cultures as compared to controls and LH treated cultures. LH led to maximal elevation of ERK in long term cultures. INTERPRETATION & CONCLUSIONS: As pERK1/2 promotes cellular proliferation, activation of ERK1/2 in LH treated cultures may be responsible for sustained growth. Prolonged LH treatment promoted growth and proliferation in caprine ovarian granulosa cells whereas prolonged exposure to hCG led to elevated levels of cAMP and decreased the rate of proliferation. Defining the signals and second messengers that act as survival or apoptotic mediators may help in elucidation of the mechanisms controlling proliferation or programmed cell death in granulosa cells.

Involvement of mitochondrial ribosomal proteins in ribosomal RNA-mediated protein folding.

The peptidyl transferase center of the domain V of large ribosomal RNA in the prokaryotic and eukaryotic cytosolic ribosomes acts as general protein folding modulator. We showed earlier that one part of the domain V (RNA1 containing the peptidyl transferase loop) binds unfolded protein and directs it to a folding competent state (FCS) that is released by the other part (RNA2) to attain the folded native state by itself. Here we show that the peptidyl transferase loop of the mitochondrial ribosome releases unfolded proteins in FCS extremely slowly despite its lack of the rRNA segment analogous to RNA2. The release of FCS can be hastened by the equivalent activity of RNA2 or the large subunit proteins of the mitochondrial ribosome. The RNA2 or large subunit proteins probably introduce some allosteric change in the peptidyl transferase loop to enable it to release proteins in FCS.

Alteration in inflammatory/apoptotic pathway and histone modifications by nordihydroguaiaretic acid prevents acute pancreatitis in swiss albino mice.

Reactive oxygen radicals, pro-inflammatory mediators and cytokines have been implicated in caerulein induced acute pancreatitis. Nordihydroguaiaretic acid (NDGA), a plant lignin, has marked anti-inflammatory properties. The present study aimed to investigate the possible protective effect of NDGA against caerulein induced pancreatitis. Acute pancreatitis was induced by intraperitoneal administration of eight doses of caerulein in male swiss albino mice. NDGA was administered after 9 h of acute pancreatitis induction. Pancreatic damage and the protective effect of NDGA were assessed by oxidative stress parameters and histopathology of pancreas. The mRNA expression of heat shock proteins (DNAJ C15 and HSPD1) was examined by real-time RT-PCR analysis. Expression of HSP 27, NF-κB, TNF-α, p-p38, Bcl-2, p-PP2A, procaspase-3, caspase-3 and histone modifications were examined by western blotting. NDGA attenuated the oxidative stress, led to increased plasma α-amylase and decreased IGF-1 in AP mice. It modulated the mRNA and protein levels of heat shock proteins and reduced the expression of NF-κB, TNF-α and p-p38. It increased the number of TUNEL positive apoptotic cells in the pancreas of AP mice. In addition, NDGA prevented the changes in modifications of histone H3 in acute pancreatitis. To best of our knowledge, this is the first report which suggests that NDGA prevents the progression of acute pancreatitis by involving alteration of histone H3 modifications and modulating the expression of genes involved in inflammatory/apoptotic cascade, which may be responsible for decreased necrosis and increased apoptosis in this model of acute pancreatitis.

Tannic acid ameliorates doxorubicin-induced cardiotoxicity and potentiates its anti-cancer activity: potential role of tannins in cancer chemotherapy.

Doxorubicin, an anthracycline antibiotic, is widely used in the treatment of various solid tumors including breast cancer. However, its use is limited due to a variety of toxicities including cardiotoxicity. The present study aimed to evaluate the effect of tannic acid, a PARG/PARP inhibitor and an antioxidant, on doxorubicin-induced cardiotoxicity in H9c2 embryonic rat heart myoblasts and its anti-cancer activity in MDA-MB-231 human breast cancer cells as well as in DMBA-induced mammary tumor animals. Doxorubicin-induced cardiotoxicity was assessed by measurement of heart weight, plasma LDH level and histopathology. Bcl-2, Bax, PARP-1 and p53 expression were examined by western blotting. Our results show that tannic acid prevents activation of PARP-1, reduces Bax and increases Bcl-2 expression in H9c2 cells, thus, preventing doxorubicin-induced cell death. Further, it reduces the cell viability of MDA-MB-231 breast cancer cells, increases p53 expression in mammary tumors and shows maximum tumor volume reduction, suggesting that tannic acid potentiates the anti-cancer activity of doxorubicin. To the best of our knowledge, this is the first report which shows that tannic acid ameliorates doxorubicin-induced cardiotoxicity and potentiates its anti-cancer activity both in vitro (H9c2 and MDA-MB-231 cells) as well as in in vivo model of DMBA-induced mammary tumor animals.

5-Azacytidine prevents cisplatin induced nephrotoxicity and potentiates anticancer activity of cisplatin by involving inhibition of metallothionein, pAKT and DNMT1 expression in chemical induced cancer rats.

5-Azactydine inhibits cell growth by direct cytotoxic action as well as by inhibition of DNA methyl transferase enzyme. Inhibitors of DNMT have been reported to potentiate the therapeutic activity of cisplatin in vitro. Dose dependent bone marrow toxicity, neurotoxicity and nephrotoxicity are the major side effects of cisplatin, limiting its use as an effective chemotherapeutic agent. The present study was aimed to reduce the nephrotoxic potential of cisplatin without compensating its potency. To best of our knowledge, this is the first report which shows that the combination of 5-azacytidine with cisplatin leads to remarkable reduction in nephrotoxicity, by involving inhibition of cisplatin induced metallothionein expression. 5-Azacytidine treatment with cisplatin leads to maximum reduction in tumor size in DMH induced colon cancer and tumor volume in DMBA induced breast cancer bearing SD rats. This combination regimen prevents phosphorylation and acetylation of histone H3 which may be involved in inhibition of aberrant gene expression in colon tumors. Further, 5-azacytidine potentiated cisplatin induced antitumor activity by involving decreased expression of pAKT, DNMT1 and an increased expression of p38 in colon tumors. Thus, combination of 5-azactydine with cisplatin attenuates the cisplatin induced nephrotoxicity and potentiates the anti-cancer activity which can have profound clinical implications.

Role of the ribosome in protein folding.

In all organisms, the ribosome synthesizes and folds full length polypeptide chains into active three-dimensional conformations. The nascent protein goes through two major interactions, first with the ribosome which synthesizes the polypeptide chain and holds it for a considerable length of time, and then with the chaperones. Some of the chaperones are found in solution as well as associated to the ribosome. A number of in vitro and in vivo experiments revealed that the nascent protein folds through specific interactions of some amino acids with the nucleotides in the peptidyl transferase center (PTC) in the large ribosomal subunit. The mechanism of this folding differs from self-folding. In this article, we highlight the folding of nascent proteins on the ribosome and the influence of chaperones etc. on protein folding.