Context: Paclitaxel (PTX) resistance is often associated with poor outcomes for patients with ovarian cancer (OC), but its mechanism is unknown. Clinicians are increasingly using immunotherapy in the management of OC, and the ability to assess tumor-immune interactions and identify effective, predictive, prognostic molecular biomarkers for OC is an urgent need.
Objective: The study intended to explore the potential tumorigenesis mechanisms to identify promising biomarkers and improve survival in OC patients.
Design: The research team performed a genetic analysis.
Setting: The study took place at First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China.
Outcome measures: The research team: (1) obtained GSE66957 and GSE81778 gene expression profiles from the Gene Expression Omnibus (GEO) database and identified 468 differentially expressed genes (DEGs); (2) conducted functional enrichment analysis and constructed a protein-to-protein interaction (PPI) network; (3) identified the OC survival-related genes using the Gene Expression Profiling Interactive Analysis 2 (GEPIA2) webserver and compared those genes with upregulated DEGs to identify the core genes; (4) used GEPIA2 and the Kaplan-Meier plotter to explore the expression profiles and the prognostic values of the core genes in OC; (5) used the LinkOmics, Oncomine, and GEPIA2 web servers to perform co-expression analysis and explore functional networks correlated with keratin 7 (KRT7); (6) performed correlation analyses between KRT7, the six main types of tumor-infiltrating lymphocytes (TILs), and immune signatures, using the TIMER tool; and (7) subsequently detected the KRT7 expression in the cell lines IOSE80, A2780, A2780/PTX, ho8910, skov3, and ovcar3 using quantitative reverse transcription-polymerase chain reaction (RT-qPCR) technology.
Results: High expression levels of KRT7 were significantly correlated with progression-free survival (PFS) and poor overall survival (OS) for OC patients, with logrank P = .0074 and logrank P = .014, respectively. The expression levels of KRT7 were also significantly correlated with the infiltrated neutrophil levels (r = 0.169, P = .0077). The study identified neutrophils as potential predictors of survival in OC. Moreover, the expression levels of KRT7 in OC were positively correlated with 51 (31.68%) of the 161 immune gene markers. The RT-qPCR analyses revealed a high expression of KRT7 in the paclitaxel-resistant OC cell line.
Conclusions: KRT7 is correlated with immune infiltration and paclitaxel resistance in OC patients. Therefore, clinicians could use KRT7 as a prognostic marker and a target in the development of new drugs.