I.M. Sechenov First Moscow State Medical University

About: I.M. Sechenov First Moscow State Medical University is a education organization based out in Moscow, Russia. It is known for research contribution in the topics: Medicine & Population. The organization has 7984 authors who have published 9355 publications receiving 68997 citations.

Exosomal lncRNA PCAT-1 promotes Kras-associated chemoresistance via immunosuppressive miR-182/miR-217 signaling and p27/CDK6 regulation.

Abstract: Immunosuppressive chemoresistance is a major burden in lung cancer. Recent data reveal that long noncoding RNAs (lncRNAs) present in the lung tumor microenvironment are implicated in chemoresistant-related immune deregulation, and metastasis but their exact pathogenic role is still unknown. In this study, we investigate the role of lncRNA PCAT-1 in chemoresistant immunosuppression and its involvement in tumor stroma remodeling. Findings reveal PCAT-1 to regulate Kras-related lung chemoresistance through increased expression of the immunosuppressive micrornas miR-182/miR217 in lung tissues, thus promoting a pre-metastatic niche formation and a subsequent increase in lung metastatic burden. Elevated expression of PCAT-1 negative regulates p27/CDK6 expression by inducing G0/G1 cell cycle arrest through AMPK augmentation, contributing to a tumor-promoting status. Furthermore, PCAT-1 triggered fibroblast differentiation followed by CAF/myofibroblast secretion in TME triggering a CD133/SOX2-related stem cell phenotype. Subsequent PCAT-1 knockdown impaired CAF-mediated stromal activation, and reversed chemoresistance and tumor growth in vivo. Overall, these findings demonstrate the versatile roles of PCAT-1 in sustaining lung immunosuppressive neoplasia through tumor microenvironment remodeling and provide new opportunities for effective metastasis inhibition, especially in chemoresistant tumors.

Microbial transformation of azaarenes and potential uses in pharmaceutical synthesis.

Abstract: Pyridine, quinoline, acridine, indole, carbazole, and other heterocyclic nitrogen-containing compounds (azaarenes) can be transformed by cultures of bacteria and fungi to produce a variety of new derivatives, many of which have biological activity. In many cases, the microbial biotransformation processes are regio- and stereoselective so that the transformation products may be useful for the synthesis of new candidate drugs.

Prognostic value of age, subglottic, and anterior commissure involvement for early glottic carcinoma treated with CO2 laser transoral microsurgery: a retrospective, single-center cohort study of 261 patients.

Abstract: CO2 laser transoral microsurgery for glottic carcinoma, when indicated, has the well-established advantages of low morbidity and positive oncological outcomes. The present study aims to determine how patient age, and tumor site could negatively impact prognosis; other variables such as the status of the margins of resection, tobacco and alcohol intake, and the grade of differentiation of the tumors have been evaluated. This was a retrospective analysis on 261 patients with a glottic carcinoma who underwent CO2 laser transoral microsurgery. The impact of different variables was calculated using univariate and multivariate analyses. The study included 248 males and 13 females. The median follow-up period was 4.3 years. Five-year disease-specific survival, recurrence-free survival, local control with laser alone, overall laryngeal preservation, and overall survival rates were 99.4, 92.2, 93.8, 97.6, and 85.5%, respectively. Equivalent results were observed in young and elderly patients. Patients with positive margins after CO2 laser transoral microsurgery showed a reduced local control with laser alone. T2 patients with true subglottic spreading and patients with anterior commissure involvement of grade 3 (Rucci’s classification) experienced worse local control rates, despite free surgical margins confirmed by histology. CO2 laser transoral microsurgery is an effective and reproducible single-stage modality therapy for young and elderly patients with glottic carcinoma. Superficial close margins can be managed by a careful wait-and-see policy, while positive margins should undergo surgical enlargement. In our experience, undifferentiated tumors, true subglottic extension, and anterior commissure involvement of grade 3 were associated with worse outcomes.

Hypoosmotic stress induces R loop formation in nucleoli and ATR/ATM-dependent silencing of nucleolar transcription.

Abstract: The contribution of nucleoli to the cellular stress response has been discussed for over a decade. Stress-induced inhibition of RNA polymerase I-dependent transcription is hypothesized as a possible effector program in such a response. In this study, we report a new mechanism by which ribosomal DNA transcription can be inhibited in response to cellular stress. Specifically, we demonstrate that mild hypoosmotic stress induces stabilization of R loops in ribosomal genes and thus provokes the nucleoli-specific DNA damage response, which is governed by the ATM- and Rad3-related (ATR) kinase. Activation of ATR in nucleoli strongly depends on Treacle, which is needed for efficient recruitment/retention of TopBP1 in nucleoli. Subsequent ATR-mediated activation of ATM results in repression of nucleolar transcription.