Downregulation of HS6ST2 Inhibits Cervical Cancer Cell Migration and Invasion in Vivo and in Vitro

Emerging evidence indicates the importance of heparan sulfate 6-O-sulfotransferase 2 (HS6ST2) in a number of developmental processes. Little is known regarding its biological function in regulating cervical cancer (CC) progression. In this study, we aim to explore the role of HS6ST2 in CC progression.

The transcriptome sequencing data of CC tissues from three databases, GSE64217, GSE138080, and GSE63514, was examined for genes with significant changes. The expression profile for HS6ST2 within CC tissue was then assessed through fluorescence quantitative PCR and immunohistochemistry and compared to data from patients with clinicopathological features. A multivariate survival analysis was performed using the COX regression. The real-time quantitative PCR assessed the HS6ST2 expression profile within CC cellular cultures. The results of knocking down HS6ST2, considering the proliferative activity and invasiveness of CC cultures in vitro, were detected through cell viability assay, clonogenic assessment, tumorsphere formation analysis, 3D invasion experiment and transwell assay. The impact of HS6ST2 knockdown in CC proliferation was also evaluated in vivo using a nude mice model.

HS6ST2 was severely upregulated within CC tissues across the three explored databases (GSE64217, GSE138080, and GSE63514). Fluorescent quantitative PCR and immunohistochemistry experiments identified HS6ST2 as highly upregulated within patients CC tissues. Survival analysis taking into account the parameters of lymph node metastasis, Federation of Gynecology and Obstetrics (FIGO) stage, depth of invasion, pathological grade, and HS6ST2 expression level demonstrated that individuals with downregulated HS6ST2 exhibited considerably extended progression-free survival (PFS) and overall survival (OS) in comparison to upregulated HS6ST2 cases. According to the findings of COX univariate analysis, the parameters lymph node metastasis, FIGO stage, depth of invasion, pathological grade, and HS6ST2 expression level, all showed a statistically significant correlation with effect upon prognosis of CC patients. The FIGO stage, depth of invasion and expression level of HS6ST2 were identified as independent risk variables influencing CC case prognosis within subsequent COX multivariate analysis. Cell function experiments proved that HS6ST2 knockdown can considerably diminish the proliferative potential, stemness and invasive traits of CC cells. Tumor formation experiments in nude mice in vivo demonstrated that knocking down HS6ST2 can significantly thwart CC cellular proliferative properties within animal models.

The clinicopathological features and the survival time of the patients significantly correlate with the level of HS6ST2 expression in CC tissue samples.