CCT6A regulates cervical cancer cell glycolysis and proliferation under hypoxic conditions via the TCAB1/TERT.

OBJECTIVES: Cervical cancer is one of the most common female malignancies worldwide, a hypoxic microenvironment usually causes enhanced viability and glycolytic capacity of cervical cancer cells. The aim of this study was to investigate the association between chaperonin containing t-complex polypeptide 1 subunit 6A (CCT6A) and cell proliferation as well as hypoxic glycolysis.

DESIGN: Bioinformatics analysis was conducted to explore the association between cervical cancer and its partner protein under hypoxic conditions, namely CCT6A. Subsequently, the expression of CCT6A was silenced, and the effects of CCT6A silencing on cervical cancer cell proliferation, cell cycle, glycolysis-related proteins, and telomerase activity were examined.

MATERIALS, SETTING, METHODS: Bioinformatics analysis was performed to investigate the expression of CCT6A in cervical cancer under hypoxic conditions. The expression of CCT6A was silenced in cervical cancer cells, Hela and Siha, to study its effects on cell proliferation and hypoxic glycolysis. The localization of telomerase activity-related proteins, TCAB1 and TERT, was detected using immunofluorescence, and their interaction was assessed using immunoprecipitation. A cellular hypoxia model was established, and the products of the glycolysis reaction were detected. A nude mouse tumor model was constructed, and the changes in glycolysis-related proteins in tumor tissues were examined using western blot, while Ki67 expression in tumor tissues was evaluated by immunohistochemistry.

RESULTS: Telomerase activity was found to be enhanced in CCT6A-silenced cervical cancer cells, along with an increase in telomerase cajal body protein 1 (TCAB1) and telomerase reverse tranase (TERT) protein binding associated with telomerase activity. Additionally, the proportion of cells in the Gap 2/mitosis (G2/M) stage and the 5-ethynyl-2'-deoxyuridine (EdU) positivity rate were decreased in CCT6A-silenced cells, indicating a reduction in cell proliferation. The expression of cell cycle-related proteins, including Cyclin E, CCNA2 and cyclin-dependent kinase 2 (CDK2), was suppressed. Furthermore, under a hypoxic environment, silencing CCT6A led to a significant reduction in cell viability and downregulation of glycolysis-related proteins, such as lactate dehydrogenase A (LDHA) and hexokinase 2 (HK2). Mechanistically, silencing CCT6A may reduce telomerase activity by inhibiting the TCAB1/TERT interaction. Additionally, TERT was found to activate the promoter region of the HK2 gene, and inhibition of TERT activity reduced the transcriptional level of HK2.

LIMITATIONS: The study primarily explored the involvement of CCT6A in cervical cancer, yet it did not account for the myriad of other elements potentially influencing cell proliferation and glycolysis. It's essential to recognize that cervical cancer's etiology is multifaceted, shaped by an array of genetic variations, environmental influences, and protein interactions.

CONCLUSIONS: Silencing CCT6A could effectively attenuate the upregulation of cell proliferation and glycolytic function mediated by TCAB1/TERT in cervical cancer cells.