School of Health Sciences, Universiti Sains Malaysia, 16150, Kota Bharu, Kelantan, Malaysia.
Appl Biochem Biotechnol. 2024 Jul;196(7):4234-4255. doi: 10.1007/s12010-023-04762-w. Epub 2023 Nov 3.
E6 and E7 human papillomavirus (HPV) oncoproteins play a significant role in the malignant transformation of infected cervical cancer cells via suppression of tumour suppressor pathways by targeting p53 and pRb, respectively. This study aimed to investigate the anticancer effects of Oroxylum indicum (OI) leaves' methanol extract on SiHa cervical cancer cells. Expression of apoptosis-related proteins (Bcl-2, caspase (cas)-3, and cas-9), viral oncoproteins (E6 and E7), and tumour suppressor proteins (p53 and pRb) were evaluated using western blot analysis before and after E6/E7 small interfering RNAs (siRNAs) transfection. In addition, the E6/E7 mRNA expression levels were assessed with real-time (RT)-PCR. The present study showed that the OI extract effectively hindered the proliferation of SiHa cells and instigated increments of cas-3 and cas-9 expressions but decreased the Bcl-2 expressions. The OI extract inhibited E6/E7 viral oncoproteins, leading to upregulation of p53 and pRb tumour suppressor genes in SiHa cells. Additionally, combinatorial treatment of OI extract and gossypin flavonoid induced restorations of p53 and pRb. Treatment with OI extract in siRNA-transfected cells also further suppressed E6/E7 expression levels and further upregulations of p53 and pRb proteins. In conclusion, OI extract treatment on siRNAs-transfected SiHa cells can additively and effectively block E6- and E7-dependent p53 and pRb degradations. All these data suggest that OI could be explored for its chemotherapeutic potential in cervical cancer cells with HPV-integrated genomes.
E6 和 E7 人乳头瘤病毒 (HPV) 癌蛋白通过分别靶向 p53 和 pRb 抑制肿瘤抑制途径,在受感染的宫颈癌细胞的恶性转化中发挥重要作用。本研究旨在研究番石榴叶甲醇提取物对 SiHa 宫颈癌细胞的抗癌作用。使用 Western blot 分析在转染 E6/E7 小干扰 RNA (siRNA) 前后评估细胞凋亡相关蛋白 (Bcl-2、caspase (cas)-3 和 cas-9)、病毒癌蛋白 (E6 和 E7) 和肿瘤抑制蛋白 (p53 和 pRb) 的表达。此外,使用实时 (RT)-PCR 评估 E6/E7 mRNA 表达水平。本研究表明,番石榴叶提取物有效抑制 SiHa 细胞的增殖,并促使 cas-3 和 cas-9 表达增加,但降低 Bcl-2 表达。番石榴叶提取物抑制 E6/E7 病毒癌蛋白,导致 SiHa 细胞中 p53 和 pRb 肿瘤抑制基因上调。此外,番石榴叶提取物与棉酚类黄酮联合治疗诱导 p53 和 pRb 的恢复。在转染 siRNA 的细胞中用番石榴叶提取物处理也进一步抑制了 E6/E7 的表达水平,并进一步上调了 p53 和 pRb 蛋白的表达。总之,番石榴叶提取物处理转染 siRNA 的 SiHa 细胞可有效抑制 E6 和 E7 依赖性 p53 和 pRb 降解。所有这些数据表明,番石榴可能因其在 HPV 整合基因组的宫颈癌细胞中的化学治疗潜力而被探索。