Biology subjects

Nagari, A.

Publications and source records attributed to Nagari, A..

2 recordsLinked to original sources

bioRxiv2025

X-Linked Cancer-Associated Polypeptide (XCP) from lncRNA1456 Cooperates with PHF8 to Regulate Gene Expression and Cellular Pathways in Breast Cancer

Recent studies have demonstrated that a subset of long "noncoding" RNAs (lncRNAs) produce functional polypeptides and proteins. In this study, we discovered a 132 amino acid protein in human breast cancer cells named XCP (X-linked Cancer-associated Polypeptide), which is encoded by lncRNA1456 (a.k.a. RHOXF1P3), a transcript previously thought to be noncoding. lncRNA1456 is a pancreas- and testis-specific RNA whose gene is located on chromosome X. We found that the expression of lncRNA1456 and XCP are highly upregulated in the luminal A, luminal B, and HER2 molecular subtypes of breast cancer. XCP modulates both estrogen-dependent and estrogen-independent growth of breast cancer cells by regulating cancer pathways, as shown in cell and xenograft models. XCP shares some homology with homeodomain-containing proteins and interacts with the histone demethylase plant homeodomain finger protein 8 (PHF8), which is also encoded by an X-linked gene. Mechanistically, XCP stimulates the histone demethylase activity of PHF8 to regulate gene expression in breast cancer cells. These findings identify XCP as a coregulator of transcription and emphasize the need to interrogate the potential functional roles of open reading frames originating from noncoding RNAs. Statement of SignificangeXCP, a polypeptide encoded by an X-linked lncRNA, regulates gene expression in breast cancer cells. XCP is a chromatin-associated protein that interacts with the histone demethylase PHF8 and modulates its demethylase activity to regulate gene expression. XCP drives cancer-specific phenotypes and serves as a potential biomarker and/or target for therapeutic intervention.

cancer biology↗

bioRxiv2024

Relaxin Modulates the Genomic Actions and Biological Effects of Estrogen in the Myometrium by Reducing Estrogen Receptor Alpha Phosphorylation

Estradiol (E2) and relaxin (Rln) are steroid and polypeptide hormones, respectively, with important roles in the female reproductive tract, including myometrium. Some actions of Rln, which are mediated by its membrane receptor RXFP1, require or are augmented by E2 signaling through its cognate nuclear steroid receptor, estrogen receptor alpha (ER). In contrast, other actions of Rln act in opposition to the effects of E2. Here we explored the molecular and genomic mechanisms that underlie the functional interplay between E2 and Rln in the myometrium. We used both ovariectomized female mice and immortalized human myometrial cells expressing wild-type or mutant ER (hTERT-HM-ER cells). Our results indicate that Rln modulates the genomic actions and biological effects of estrogen in the myometrium and myometrial cells by reducing phosphorylation of ER on serine 118 (S118), as well as by reducing the E2-dependent binding of ER across the genome. These effects were associated with changes in the hormone-regulated transcriptome, including a decrease in the E2-dependent expression of some genes and enhanced expression of others. The inhibitory effects of Rln cotreatment on the E2-dependent phosphorylation of ER required the nuclear dual-specificity phosphatases DUSP1 and DUSP5. Moreover, the inhibitory effects of Rln were reflected in a concomitant inhibition of the E2-dependent contraction of myometrial cells. Collectively, our results identify a pathway that integrates Rln/RXFP1 and E2/ER signaling, resulting in a convergence of membrane and nuclear signaling pathways to control genomic and biological outcomes.

molecular biology↗