Biology subjects

Nanda, J. S.

Publications and source records attributed to Nanda, J. S..

4 recordsLinked to original sources

bioRxiv2021

IL1B loss is associated with increased AR activity in castration-resistant prostate cancer

Castration-resistant prostate cancer represents a continuum of phenotypes, including tumors with high levels of androgen receptor (AR) expression and activity and those which do not express AR and rely on alternative pathways for survival. The process by which AR-positive prostate cancer cells and tumors lose AR expression and acquire neuroendocrine features is referred to as neuroendocrine differentiation. Numerous therapies and exposures have been demonstrated to induce neuroendocrine differentiation in vitro, including the pro-inflammatory cytokine, interleukin 1 beta (IL-1{beta}), encoded by the gene IL1B. The purpose of our studies was to determine the relationship between the expression and activity of AR in relationship to IL-1{beta} and IL1B in prostate cancer. We performed analysis of de-identified human clinical data and generated prostate cancer cell lines with overexpression or knockout of IL1B. In primary prostate cancer, higher expression of IL1B predicts longer time to biochemical recurrence. In metastatic castration-resistant prostate cancer, IL1B expression is decreased and inversely correlates with AR and AR-target gene expression and AR activity, while positively correlating with the neuroendocrine prostate cancer (NEPC) score and neuroendocrine marker gene expression. In vitro, we report that AR-positive castration-resistant prostate cancer cells (C4-2B, 22Rv1) secrete IL-1{beta}, and knockout of IL1B in these cells results in increased AR activity, in the presence and absence of dihydrotestosterone (DHT). Importantly, knockout of IL1B prevented AR attrition during androgen-deprivation. Taken together, our studies demonstrate that loss of IL1B in AR-positive castration-resistant prostate cancer cells can increase and maintain AR activity in the absence of androgens, suggesting another potential mechanism of high AR activity in castration-resistant prostate cancer.

cancer biology↗

bioRxiv2020

Identification of genes required for enzalutamide resistance in castration-resistant prostate cancer cells in vitro

Castration-resistant prostate cancer can be treated with the anti-androgen enzalutamide, but responses and duration of response are variable. To identify genes that support enzalutamide resistance, we performed a short hairpin RNA (shRNA) screen in the bone-homing, castration-resistant prostate cancer cell line, C4-2B. We identified eleven genes (TFAP2C, CAD, SPDEF, EIF6, GABRG2, CDC37, PSMD12, COL5A2, AR, MAP3K11, and ACAT1), whose loss resulted in decreased cell survival in response to enzalutamide. To validate our screen, we performed transient knockdowns in C4-2B and 22Rv1 cells and evaluated cell survival in response to enzalutamide. Through these studies, we validated three genes (ACAT1, MAP3K11, and PSMD12) as supporters of enzalutamide resistance in vitro. Although ACAT1 expression is lower in metastatic castration-resistant prostate cancer samples versus primary prostate cancer samples, knockdown of ACAT1 was sufficient to reduce cell survival in C4-2B and 22Rv1 cells. MAP3K11 expression increases with Gleason grade, and the highest expression is observed in metastatic castration-resistant disease. Knockdown of MAP3K11 reduced cell survival and pharmacologic inhibition of MAP3K11 with CEP-1347 in combination with enzalutamide resulted in a dramatic increase in cell death. This was associated with decreased phosphorylation of AR-Serine650, which is required for maximal AR activation. Finally, while PSMD12 expression did not change during disease progression, knockdown of PSMD12 resulted in decreased AR and AR splice variant expression, likely contributing to the C4-2B and 22Rv1 decrease in cell survival. Our study has therefore identified at least three new supporters of enzalutamide resistance in castration-resistant prostate cancer cells in vitro. Financial supportThe authors would like to acknowledge funding from the Joe C. Davis Foundation (to RJM), the Vanderbilt Institute for Clinical and Translational Research (VICTR, to YY, PEC, and RJM). The Vanderbilt Institute for Clinical and Translational Research (VICTR) is funded by the National Center for Advancing Translational Sciences (NCATS) Clinical Translational Science Award (CTSA) Program, Award Number 5UL1TR002243. The content of this manuscript solely the responsibility of the authors and does not necessarily represent the official views of the NIH. We would also like to acknowledge the Case Research Institute, a joint venture between University Hospitals and Case Western Reserve University, start-up funds (to MMG), and the Cell and Molecular Biology Training Program (T32 GM 008056 to SEK).

cancer biology↗

bioRxiv2019

Nuclear factor I/B increases in prostate cancer to support androgen receptor activation

BackgroundMost prostate cancers express androgen receptor (AR), and our previous studies have focused on identifying transcription factors that modify AR function. We have shown that nuclear factor I/B (NFIB) regulates AR activity in androgen-dependent prostate cancer cells in vitro. However, the status of NFIB in prostate cancer was unknown. MethodsWe immunostained a tissue microarray including normal, hyperplastic, prostatic intraepithelial neoplasia, primary prostatic adenocarcinoma, and castration-resistant prostate cancer tissue samples for NFIB, AR, and synaptophysin, a marker of neuroendocrine differentiation. We interrogated publically available data sets in cBioPortal to correlate NFIB expression and AR and neuroendocrine prostate cancer (NEPCa) activity scores. We analyzed prostate cancer cell lines for NFIB expression via Western blotting and used nuclear and cytoplasmic fractionation to assess where NFIB is localized. We performed coimmunoprecipitation studies to determine if NFIB and AR interact. ResultsNFIB increased in the nucleus and cytoplasm of prostate cancer samples versus matched normal controls, independent of Gleason score. Similarly, cytoplasmic AR and synaptophysin increased in primary prostate cancer. We observed strong NFIB staining in primary small cell prostate cancer. The ratio of cytoplasmic-to-nuclear NFIB staining was predictive of earlier biochemical recurrence in prostate cancer, once adjusted for tumor margin status. Cytoplasmic AR was an independent predictor of biochemical recurrence. There was no statistically significant difference between NFIB and synaptophysin expression in primary and castration-resistant prostate cancer, but cytoplasmic AR expression was increased in castrationresistant samples. In primary prostate cancer, nuclear NFIB expression correlated with cytoplasmic NFIB and nuclear AR, while cytoplasmic NFIB correlated with synaptophysin, and nuclear and cytoplasmic AR. In castration-resistant prostate cancer samples, NFIB expression correlated positively with an AR activity score, and negatively with the NEPCa score. In prostate cancer cell lines, NFIB exists in several isoforms. We observed NFIB predominantly in the nuclear fraction of prostate cancer cells with increased cytoplasmic expression seen in castration-resistant cell lines. We observed an interaction between AR and NFIB through coimmunoprecipitation experiments. ConclusionWe have described the expression pattern of NFIB in primary and castrationresistant prostate cancer and its positive correlation with AR. We have also demonstrated AR interacts with NFIB.

cancer biology↗

bioRxiv2018

Cdc23/Mcm10 Primase Generates the Lagging Strand-Specific Ribonucleotide Imprint in Fission Yeast

The developmental asymmetry of fission yeast daughter cells derives from inheriting \"older Watson\" versus \"older Crick\" DNA strand from the parental cell, strands that are complementary but not identical with each other. A novel DNA strand-specific \"imprint\", installed during DNA replication at the mating-type locus (mat1), imparts competence for cell type inter-conversion to one of the two chromosome replicas. The biochemical nature of the imprint and the mechanism of its installation are still not understood. The catalytic subunit of DNA Polymerase (Pol) has been implicated in the imprinting process. Based on its known biochemical function, Pol might install the mat1 imprint during lagging strand synthesis. The nature of the imprint is not clear: it is either a nick or a ribonucleotide insertion. Our investigations do not support a role of Pol in nicking through putative endonuclease domains but confirm its role in installing an alkali-labile moiety as the imprint. A detailed genetic and molecular analysis reveals a direct role of the Cdc23/Mcm10 primase activity in installing the imprint in cooperation with Pol and Swi1.

genetics↗