Investigator
Research Associate Professor · Northwestern Medicine, Obstetrics and Gynecology
Epitranscriptomic Regulation of Platinum Resistance via the METTL3-ADAM23 Axis in Ovarian Cancer
N6-methyladenosine (m6A) has emerged as a pivotal regulator of post-transcriptional gene control, yet its contribution to chemotherapy resistance remains insufficiently defined. Here, we describe a previously unrecognized METTL3-ADAM23 epitranscriptomic regulatory relationship associated with platinum (Pt) resistance in ovarian cancer (OC). We show that cisplatin treatment increases global m6A levels and METTL3 expression, linking Pt exposure to activation of the m6A machinery. Functional perturbation studies demonstrate that METTL3 overexpression enhances cisplatin resistance, whereas METTL3 knockdown or pharmacologic inhibition with the selective METTL3 inhibitor STM2457 sensitizes OC cells to Pt treatment in vitro and improves Pt response in vivo. Transcriptomic profiling identifies ADAM23, a cell-adhesion-related tumor suppressor, as a METTL3-dependent, m6A-associated transcript, with altered mRNA expression observed across multiple experimental systems and several high-confidence predicted m6A sites within its transcript. Cisplatin-associated METTL3 upregulation correlates with reduced ADAM23 expression, suggesting a potential regulatory relationship that may contribute to chemoresistance. Together, these findings support a model in which METTL3-associated increases in m6A methylation are linked to Pt resistance, in part through modulation of ADAM23 expression, and highlight METTL3 as a potential therapeutic target in OC.
Cervical extracellular matrix hydrogel optimizes tumor heterogeneity of cervical squamous cell carcinoma organoids
Cervical cancer, primarily squamous cell carcinoma, is the most prevalent gynecologic malignancy. Organoids can mimic tumor development in vitro, but current Matrigel inaccurately replicates the tissue-specific microenvironment. This limitation compromises the accurate representation of tumor heterogeneity. We collected para-cancerous cervical tissues from patients diagnosed with cervical squamous cell carcinoma (CSCC) and prepared uterine cervix extracellular matrix (UCEM) hydrogels. Proteomic analysis of UCEM identified several tissue-specific signaling pathways including human papillomavirus, phosphatidylinositol 3-kinase–AKT, and extracellular matrix receptor. Secreted proteins like FLNA, MYH9, HSPA8, and EEF1A1 were present, indicating UCEM successfully maintained cervical proteins. UCEM provided a tailored microenvironment for CSCC organoids, enabling formation and growth while preserving tumorigenic potential. RNA sequencing showed UCEM-organoids exhibited greater similarity to native CSCC and reflected tumor heterogeneity by exhibiting CSCC-associated signaling pathways including virus protein-cytokine, nuclear factor κB, tumor necrosis factor, and oncogenes EGR1, FPR1, and IFI6. Moreover, UCEM-organoids developed chemotherapy resistance. Our research provides insights into advanced organoid technology through native matrix hydrogels.
N6-Methyladenosine RNA Modifications Regulate the Response to Platinum Through Nicotinamide N-methyltransferase
Abstract Development of resistance to platinum (Pt) in ovarian cancer remains a major clinical challenge. Here we focused on identifying epitranscriptomic modifications linked to Pt resistance. Fat mass and obesity-associated protein (FTO) is a N6-methyladenosine (m6A) RNA demethylase that we recently described as a tumor suppressor in ovarian cancer. We hypothesized that FTO-induced removal of m6A marks regulates the cellular response of ovarian cancer cells to Pt and is linked to the development of resistance. To study the involvement of FTO in the cellular response to Pt, we used ovarian cancer cells in which FTO was knocked down via short hairpin RNA or overexpressed and Pt-resistant (Pt-R) models derived through repeated cycles of exposure to Pt. We found that FTO was significantly downregulated in Pt-R versus sensitive ovarian cancer cells. Forced expression of FTO, but not of mutant FTO, increased sensitivity to Pt in vitro and in vivo (P < 0.05). Increased numbers of γ-H2AX foci, measuring DNA double-strand breaks, and increased apoptosis were observed after exposure to Pt in FTO-overexpressing versus control cells. Through integrated RNA sequencing and MeRIP sequencing, we identified and validated the enzyme nicotinamide N-methyltransferase (NNMT), as a new FTO target linked to Pt response. NNMT was upregulated and demethylated in FTO-overexpressing cells. Treatment with an NNMT inhibitor or NNMT knockdown restored sensitivity to Pt in FTO-overexpressing cells. Our results support a new function for FTO-dependent m6A RNA modifications in regulating the response to Pt through NNMT, a newly identified RNA methylated gene target.
Reliable estrogen-related prognostic signature for uterine corpus endometrial carcinoma
Uterine corpus endometrial carcinoma (UCEC) is a predominant gynecological malignancy worldwide. Overdosed estrogen exposure has been widely known as a crucial risk factor for UCEC patients. The purpose of this work is to explore crucial estrogen-related genes (ERGs) in UCEC. UCEC scRNA-seq data, bulk RNA data, and ERGs were obtained from GEO, TCGA, and Molecular Signature Database, respectively. Differential expression analysis and cross analysis determined the candidate genes, and optimal genes in risk score were obtained after univariate Cox regression analysis, LASSO Cox regression analysis, and multivariate Cox regression analysis. The functional information was revealed by GO, KEGG, and GSVA enrichment analyses. CCK8 assay was used to detect the drug sensitivity. After cross analysis of the differentially expressed genes and the 8734 ERGs, 86 differentially expressed ERGs were identified in UCEC, which were significantly enriched in some immune related pathways and microbiota related pathways. Of them, the most optimal 8 ERGs were obtained to build prognostic risk score, including GAL, PHGDH, SLC7A2, HNMT, CLU, AREG, MACC1, and HMGA1. The risk score could reliably predict patient prognosis, and high-risk patients had worse prognosis. Higher HMGA1 gene expression exhibited higher sensitivity to Osimertinib. Predictive risk score based on 8 ERGs exhibited excellent prognostic value in UCEC patients, and high-risk patients had inferior survival. UCEC patients with distinct prognoses showed different tumor immune microenvironment.
Research Associate Professor
Northwestern Medicine · Obstetrics and Gynecology