Research Information System
TURKISH JOURNAL OF MEDICAL SCIENCES, vol.54, no.6, 2024 (SCI-Expanded)
Background/aim: The p53 protein, a crucial tumor suppressor, governs cell cycle regulation and apoptosis. Similarly, p63, a member of the p53 family, exhibits traits of both tumor suppression and oncogenic behavior through its isoforms. However, the functional impact of ANp63(3, an isoform of the p63 protein, on human glioma cancer cells like T98G cells remains poorly understood, representing the novelty of this study in the current literature. Materials and methods: Employing the pRetroX-Tet-On vector system, the apoptotic effects of ANp63(3 on T98G cell lines was investigated and its influence on the cell cycle was assessed. Initially, an rtTA-expressing vector, a component of the pRetroX-Tet-On system, was established in the T98G cell lines. Subsequently, the ANp63(3 cDNA was cloned into the Retropur Tight retroviral vector and transfected into T98G cells containing the pRetroX-Tet-On system for functional analysis. The gene expression and cell cycle regulation were evaluated through reverse-transcription polymerase chain reaction and flow cytometry, determining protein translation via western blotting. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and (3-galactosidase cell staining were employed to assess the cytotoxicity and senescence of ANp63(3, respectively Results: The overexpression of ANp63(3 in the T98G cells correlated with increased cell viability and altered cell cycle regulation, notably upregulating the p21 expression independent of p53. Caspase-3/7 activity analyses showed no changes in the apoptotic genes but revealed an increase in antiapoptotic gene expression. Surprisingly, cell death in the ANp63(3-overexpressing T98G cells did not occur through apoptosis as anticipated. Instead, it resulted from the cytotoxic effects of the ANp63(3 protein. Conclusion: Ap63(3 increased the p21 levels, induced cell death, and caused cell cycle arrest at the G1 phase, while exhibiting antiapoptotic properties and promoting senescence. Unexpectedly, overexpression of Ap63(3 in T98G cells led to significant cell death, potentially through necrosis rather than apoptosis, suggesting a complex role for Ap63(3 in cell cycle regulation and tumor suppression.