Biology subjects

DAS, P.

Publications and source records attributed to DAS, P..

2 recordsLinked to original sources

bioRxiv2023

Calcimycin mediates apoptosis in Breast and Cervical cancer cells by inducing intracellular calcium levels in a P2RX4-dependent manner

Calcimycin (A23187) is a polyether antibiotic and divalent cation ionophore, extracted from Streptomyces chartrecensis. With wide variety of antimicrobial activities, it also exhibits cytotoxicity of tumor cells. Calcimycin exhibit therapeutic potential against tumor cell growth; however, the molecular mechanism remains to be fully elucidated. Present study explores the mechanism of calcimycin-induced apoptosis cancer cell lines. Calcimycin induces apoptosis accompanied by increased intracellular calcium-level and increased expression of purinergic receptor-P2RX4, a ligand-gated ion channel. The percentage of apoptotic cancer cells in a dose-dependent manner quickly rose as recorded with MTT assays, Phase contrast imaging, wound healing assay, fluorescence imaging by DAPI and AO/EB staining and FACS. Mitochondrial potential was analyzed by TMRM assay as Ca2+ signaling is well known to be influenced and synchronized by mitochondria also. Calcimycin treatment tends to increase the intracellular calcium level, mRNA expression of ATP receptor P2RX4, and phosphorylation of p38. Blocking of either intracellular calcium by BAPTA-AM, P2RX4 expression by antagonist 5-BDBD, and phospho-p38 by SB203580, abrogated the apoptotic activity of calcimycin. Taken together, these results show that calcimycin induces apoptosis in P2RX4 dependent ATP mediated intracellular Ca2+ and p38 MAPK mediated pathway in both the cancer cell lines.

cancer biology↗

bioRxiv2022

An in vitro and computational validation of a novel loss-of-functional mutation in PAX9 associated with non-syndromic tooth agenesis

Congenital tooth agenesis (CTA) is one of the most common craniofacial anomalies. Its frequency varies among different population depending upon the genetic heterogeneity. CTA could be of familial or sporadic and syndromic or non-syndromic. Five major genes are found to be associated with non-syndromic CTA namely, PAX9, MSX1, EDA1, AXIN2 and WNT10A. In this study, an India family with CTA was investigated and a novel c.336C>G variation was identified in the exon 3 of PAX9, leading to substitution of evolutionary conserved Cys with Trp at 112 amino acid position located at the functionally significant DNA binding paired domain region. Functional analysis revealed that p.Cys112Trp mutation did not prevent the nuclear localization although mutant protein had higher cytoplasmic retention. EMSA using e5 probe revealed that mutant protein was unable to bind with the paired-domain binding site. Subsequently, GST pull-down assay revealed lower binding activity of the mutant protein with its known interactor MSX1. Further RNA-sequencing of PAX9 over-expressed HEK293, identified two potential novel targets, WNT4 and WNT7b those are up-regulated by wild-type PAX9 but not by mutant. These in vitro results were consistent with the computational results. The in vitro and computational observations altogether suggest that c.336C>G (p.Cys112Trp) variation leads to loss-of-function of PAX9 leading to CTA in this family.

molecular biology↗