Biology subjects

Behera, M.

Publications and source records attributed to Behera, M..

4 recordsLinked to original sources

bioRxiv2026

Integrated miRNA-protein profiling of small extracellular vesicle cargo reveals dynamic cargo remodelling during tissue repair in UV-C-damaged C. elegans

Ultraviolet-C (UV-C) radiation is a potent environmental stressor that induces DNA damage, accumulation of reactive oxygen species (ROS), and cellular dysfunction. This also initiates coordinated molecular responses to regulate cellular adaptation and recovery. Small extracellular vesicles (sEVs) have emerged as key mediators of intercellular communication through the selective incorporation of microRNAs (miRNAs), proteins, and lipids. However, the temporal changes of sEV-associated cargo during the progression from UV-C-induced damage to recovery remain uncharacterized. We hypothesised that UV-C exposure induces stage-specific changes in sEV cargo (miRNA and proteins) that promote the transition of cells from damage to the response and recovery phases. To examine this, a time-resolved UV-C exposure model was established using Caenorhabditis elegans (C. elegans). In this paper, we studied 2.5 hours of UV-C exposure, including cellular damage, intracellular ROS levels, and DNA integrity, to define the damage and repair state. Based on these temporal variations, samples were collected: i) immediately after exposure, ii) 6 hours post-exposure, and iii) 16 hours post-exposure were designated as damage, response, and recovery conditions, respectively. sEVs isolated from whole-worm preparations were characterised using biophysical and molecular approaches, followed by miRNA sequencing and proteomic analyses. Integrative analysis further identified miRNA-protein associations and associated them with pathways involved in stress adaptation, metabolism, signal transduction, and cellular homeostasis. Collectively, these findings provide a temporal molecular framework of sEV cargo associated with UV-C-induced damage, response, and recovery in C. elegans. Overall, this study identified candidate molecular signatures and miRNA-protein associations that underlie the temporally selective packaging of sEV-associated cargo following UV-C-induced damage, providing a basis for future tissue-specific and mechanistic investigations.

molecular biology↗

bioRxiv2024

DNA polymerase kappa stabilized by PTBP2 interacts with MRE11 and promotes genomic instability in leukemia cells

Polypyrimidine tract binding protein 2 (PTBP2) is an RNA-binding protein that controls alternative splicing in neuronal, muscle, and Sertoli cells. Our study unveils a novel role of PTBP2 in promoting the excessive production of the DNA polymerase kappa (Pol{kappa}) by stabilizing its 3UTR. We observed an association between its increased expression and the upregulation of PTBP2 in clinical samples of Chronic Myeloid Leukemia (CML). Ptbp2 knock-out CML cell lines and patient samples treated with hydroxyurea presented with increased DNA damage, as evidenced by long comet tails and higher levels of the DNA damage marker, {gamma}H2AX foci, however overexpression of Pol{kappa} in the Ptbp2-KO cells restored normal phenotype. The deregulation of the DNA repair pathway is a defining feature of malignancies and is closely associated with genomic instability. POLK was found to interact with MRE11 of the MRN complex, thereby governing the activation of ATM-CHK2. Cells with elevated levels of Ptbp2 and Pol{kappa} demonstrated increased sister chromatid exchange and BrdU incorporation in ex-vivo assays, while multinucleated cells with multipolar spindles were observed in in-vivo assays. Our findings confirm the critical role of the PTBP2-POLK axis in driving genomic instability and bolstering the viability of cells with increased malignancy.

cancer biology↗

bioRxiv2023

Loss of the endocytic tumor suppressor HD-PTP phenocopies LKB1 and promotes RAS-driven oncogenesis.

Abstract/SummaryOncogenic RAS mutations drive aggressive cancers that are difficult to treat in the clinic, and while direct inhibition of the most common KRAS variant in lung adenocarcinoma (G12C) is undergoing clinical evaluation, a wide spectrum of oncogenic RAS variants together make up a large percentage of untargetable lung and GI cancers. Here we report that loss-of-function alterations (mutations and deep deletions) in the gene that encodes HD-PTP (PTPN23) occur in up to 14% of lung cancers in the ORIEN Avatar lung cancer cohort, associate with adenosquamous histology, and occur alongside an altered spectrum of KRAS alleles. Furthermore, we show that in publicly available early-stage NSCLC studies loss of HD-PTP is mutually exclusive with loss of LKB1, which suggests they restrict a common oncogenic pathway in early lung tumorigenesis. In support of this, knockdown of HD-PTP in RAS-transformed lung cancer cells is sufficient to promote FAK-dependent invasion. Lastly, knockdown of the Drosophila homolog of HD-PTP (dHD-PTP/Myopic) synergizes to promote RAS-dependent neoplastic progression. Our findings highlight a novel tumor suppressor that can restrict RAS-driven lung cancer oncogenesis and identify a targetable pathway for personalized therapeutic approaches for adenosquamous lung cancer.

cancer biology↗

bioRxiv2022

Symbolic quantitative cognition in wild zebrafish (Danio rerio)

Zebrafish (Danio rerio) constitute an excellent model system to investigate the neural and genetic basis of quantitative cognition We tested the ability of reward quantity discrimination of wild-type zebrafish in an associative learning task. We used an operant conditioning paradigm in which the number of horizontal lines zebrafish approached in a 2-alternative forced choice task predicted the number of food reward pellets they would receive. Zebrafish did not learn a preference for the 2-line stimulus predictive of receiving 2 food pellets. However, a subset of the fish performed significantly above chance in a discrimination task with the same apparatus, in which the 2-line stimulus was associated with the same reward but the choice of the 1-line stimulus was not rewarded. Zebrafish also showed a population level learning in a simpler spatial association task with the same apparatus. We also explored the explanatory value of alternative spatial learning hypotheses such as a Win-Stay, Lose-Shift (WSLS) strategy at the individual level for fish in navigating these spatially randomised tasks.

animal behavior and cognition↗