ELK4 Promotes Cell Cycle Progression and Stem Cell-like Characteristics in HPV-associated Cervical Cancer by Regulating the FBXO22/PTEN Axis.

BACKGROUND

Cervical cancer (CC) is a prevalent gynecological carcinoma, and patients infected with human papillomavirus (HPV) have a higher morbidity rate.

AIMS

To explore the effects of ETS-like transcription factor 4 (ELK4) in patients with HPV CC.

STUDY DESIGN

In vitro cell lines and human-sample study.

METHODS

The ELK4 levels in human tissue (65 HPV CC tissue and 25 HPV normal cervical tissue) and cell lines (human cervical epithelial immortalized cell line H8 and CC cell lines HeLa [HPV18], CaSki [HPV16], and SiHa [HPV]) were quantified using qRT-PCR and western blot assay. ELK4 knockdown transfection was effective and confirmed by western blotting. The MTT and EDU assays were used to evaluate cell viability and proliferation, respectively. Flow cytometry was used to detect the CC cell cycle stage. Stem cell markers, such as cluster of differentiation 133 (CD133), CD44, and aldehyde dehydrogenase 1, and the cervicospheres formed were measured. ChIP-qPCR and luciferase activity experiments were used to assess the bond between ELK4 and F-box protein 22 (FBXO22).

RESULTS

ELK4 was highly expressed in the HPV CC tissue. CC cells with ELK4 knockdown had lower viability and proliferation than the control cells. ELK4 knockdown blocked the progression of the cell cycle from G1 to S phase. ELK4 knockdown suppressed the stem cell-like characteristics of the HPV CC cells. ELK4 bonded with the FBXO22 promoter, inhibiting the levels of phosphatase and tensin homolog (PTEN).

CONCLUSION

ELK4 facilitated cell cycle progression and stem cell-like characteristics by regulating the FBXO22/PTEN axis. Thus, ELK4 could be a potential therapeutic target to arrest the progress of HPV-associated CC.