| dc.description.abstracteng | Cervical cancer (CC) remains the fourth most common malignancy among women worldwide, despite effective HPV vaccination strategies. CC can be classified into different histological subtypes. The majority of cases are cervical squamous cell carcinomas (CSCC), followed by adenocarcinomas (CAC), the latter including a higher proportion of HPV-negative tumors. These subtypes differ in their etiology, pathology, and clinical presentation. While the incidence of CSCC has been declining, CAC incidence has increased in recent years.
GPER1 is a membrane-bound G protein-coupled receptor with seven transmembrane domains that activates various intracellular signaling cascades. These include cAMP production, the Rho-ROCK pathway, and EGFR transactivation, which subsequently stimulate MAPK and Akt pathways. Through HIF-1α, GPER1 further modulates NOTCH and VEGF signaling. GPER1 plays a relevant role in the initiation and progression of several malignancies, including CC.
To elucidate the specific role of GPER1 in CC, stable overexpression (OE) of GPER1 was established in the CC cell lines SiHa and HeLa using a non-viral Sleeping-Beauty transposon-based vector. Stable GPER1-OE was confirmed by RT-qPCR, Western blotting, and flow cytometry (FACS). Functional consequences of GPER1-OE were assessed by examining tumor-associated cellular behaviors including proliferation, migration, invasion, apoptosis, metabolic viability, as well as stem-cell-associated properties via colony- and tumorsphere-formation assays. In addition, next-generation sequencing (NGS) was conducted to identify differential gene expression and signaling pathways particularly relevant for tumor development and progression.
Overall, GPER1-OE resulted in a more aggressive phenotype in SiHa cells (CSCC), characterized by increased proliferation, migration, and enhanced cancer stem-cell-like traits. In contrast, HeLa cells (CAC) displayed a less aggressive phenotype, with reduced proliferation and migration, increased apoptosis, and diminished stem-cell properties. The NGS analysis supported these findings, revealing an upregulation of mTOR, MYC, p53, EMT, and angiogenesis-related pathways in SiHa cells with GPER1-OE, whereas these pathways were predominantly downregulated in HeLa cells, accompanied by suppressed Hedgehog, KRAS, and Wnt/β-catenin signaling. These results suggest that GPER1 can exert either tumor-promoting or tumor-suppressive effects in CC depending on the histological subtype. | de |