Fang-rong Shen

A first-in-class POLRMT specific inhibitor IMT1 suppresses endometrial carcinoma cell growth

AbstractExploring novel molecularly-targeted therapies for endometrial carcinoma is important. The current study explored the potential anti-endometrial carcinoma activity by a first-in-class POLRMT (RNA polymerase mitochondrial) inhibitor IMT1. In patient-derived primary human endometrial carcinoma cells and established lines, treatment with IMT1 potently inhibited cell viability, proliferation, cell-cycle progression and motility, while inducing robust caspase-apoptosis activation. Treatment with the PLORMT inhibitor impaired mitochondrial functions, leading to mtDNA (mitochondrial DNA) transcription inhibition, mitochondrial membrane potential decline, reactive oxygen species formation, oxidative stress and ATP loss in the endometrial carcinoma cells. Similarly, POLRMT depletion, through shRNA-induced silencing or CRISPR/Cas9-caused knockout (KO), inhibited primary endometrial carcinoma cell proliferation and motility, and induced mitochondrial dysfunction and apoptosis. Importantly, IMT1 failed to induce further cytotoxicity in POLRMT-KO endometrial carcinoma cells. Contrarily, ectopic overexpression of POLRMT further augmented proliferation and motility of primary endometrial carcinoma cells. In vivo, oral administration of a single dose of IMT1 substantially inhibited endometrial carcinoma xenograft growth in the nude mice. mtDNA transcription inhibition, oxidative stress, ATP loss and apoptosis were detected in IMT1-treated endometrial carcinoma xenograft tissues. Together, targeting PLORMT by IMT1 inhibited endometrial carcinoma cell growth in vitro and in vivo.

Unveiling the ZNF384-INTS13-hnRNPC axis as a therapeutic vulnerability in cervical cancer

Abstract Cervical cancer remains a major global health burden, necessitating the identification of novel therapeutic targets to overcome the limitations of current treatments. Here, we comprehensively investigated the role of integrator complex subunit 13 (INTS13) in cervical cancer progression. Our analysis of publicly available The Cancer Genome Atlas (TCGA) datasets revealed that INTS13 is significantly overexpressed in cervical cancer tissues across various histological subtypes, correlating with advanced tumor T-stage and predicting poorer overall survival. Single-cell RNA sequencing further localized INTS13 expression predominantly to malignant epithelial cells within the tumor microenvironment, where its expression correlated with genes involved in critical cellular processes. Furthermore, elevated expression has been observed in cervical cancer tissues from surgically-treated patients and in various primary human cervical cancer cells. In vitro functional studies demonstrated that genetic silencing or CRISPR/Cas9-mediated knockout of INTS13 significantly inhibited the proliferation, migration, and invasion of primary cervical cancer cells, while selectively inducing apoptosis. Conversely, ectopic INTS13 overexpression markedly enhanced these malignant phenotypes. Mechanistically, we identified heterogeneous nuclear ribonucleoprotein C (hnRNPC) as a critical downstream effector, with INTS13 regulating hnRNPC expression, and the restoration of hnRNPC effectively reversing the anti-cervical cancer effects observed upon INTS13 silencing. Furthermore, the transcription factor ZNF384 (zinc finger protein 384) was identified as an upstream regulator that directly binds to and positively governs INTS13 expression. Finally, in vivo animal models confirmed that targeted silencing of INTS13 significantly impeded cervical cancer xenograft growth in nude mice, reduced cellular proliferation, and augmented apoptosis, consistently accompanied by a reduction in hnRNPC expression. These findings collectively establish INTS13 as a crucial precancerous gene in cervical cancer, promoting malignant phenotypes primarily through the ZNF384-INTS13-hnRNPC signaling axis.