Department of Life Science and Agroforestry, Qiqihar University, Qiqihar, Heilongjiang 161006, P.R. China.
Mol Med Rep. 2022 Oct;26(4). doi: 10.3892/mmr.2022.12835. Epub 2022 Aug 31.
Cytidine triphosphate synthase (CTPS) forms filamentous structures termed cytoophidia in numerous types of cell. Toosendanin (TSN) is a tetracyclic triterpenoid and induces CTPS to form cytoophidia in MKN45 cells. However, the effects of CTPS cytoophidia on the proliferation and apoptosis of human gastric cancer cells remain poorly understood. In the present study, CTPS‑overexpression and R294D‑CTPS mutant vectors were generated to assess the effect of CTPS cytoophidia on the proliferation and apoptosis of gastric cancer MKN45 cells. Formation of CTPS cytoophidia significantly inhibited MKN45 cell proliferation (evaluated using EdU incorporation assay), significantly blocked the cell cycle in G phase (assessed using flow cytometry) and significantly decreased mRNA and protein expression levels of cyclin D1 (assessed by reverse transcription‑quantitative PCR and western blotting, respectively). Furthermore, the number of apoptotic bodies and apoptosis rate were markedly elevated and mitochondrial membrane potential was markedly decreased. Moreover, mRNA and protein expression levels of Bax increased and Bcl‑2 decreased markedly in MKN45 cells following transfection with the CTPS‑overexpression vector. The proliferation rate increased, percentage of G/G‑phase cells decreased and apoptosis was attenuated in cells transfected with the R294D‑CTPS mutant vector and this mutation did not lead to formation of cytoophidia. The results of the present study suggested that formation of CTPS cytoophidia inhibited proliferation and promoted apoptosis in MKN45 cells. These results may provide insights into the role of CTPS cytoophidia in cancer cell proliferation and apoptosis.
三磷酸胞苷合酶 (CTPS) 在许多类型的细胞中形成称为细胞丝状伪足的丝状结构。川楝素 (TSN) 是一种四环三萜类化合物，可诱导 MKN45 细胞中 CTPS 形成细胞丝状伪足。然而，CTPS 细胞丝状伪足对人类胃癌细胞增殖和凋亡的影响仍知之甚少。本研究构建了 CTPS 过表达和 R294D-CTPS 突变载体，以评估 CTPS 细胞丝状伪足对胃癌 MKN45 细胞增殖和凋亡的影响。CTPS 细胞丝状伪足的形成显著抑制了 MKN45 细胞的增殖（通过 EdU 掺入实验评估），显著阻断了细胞周期的 G1 期（通过流式细胞术评估），并显著降低了细胞周期蛋白 D1 的 mRNA 和蛋白表达水平（分别通过逆转录-定量 PCR 和 Western blot 评估）。此外，凋亡小体的数量和凋亡率明显增加，线粒体膜电位明显降低。此外，转染 CTPS 过表达载体后，MKN45 细胞中 Bax 的 mRNA 和蛋白表达水平明显增加，Bcl-2 明显减少。转染 R294D-CTPS 突变载体后，细胞增殖率增加，G1/G0 期细胞比例降低，细胞凋亡减弱，且该突变不导致细胞丝状伪足的形成。本研究结果表明，CTPS 细胞丝状伪足的形成抑制了 MKN45 细胞的增殖并促进了细胞凋亡。这些结果可能为 CTPS 细胞丝状伪足在肿瘤细胞增殖和凋亡中的作用提供了新的见解。
