ABSTRACT
@#[摘 要] 目的：探讨白术（Atractylodes macrocephala）水提物抑制胃癌SGC-7901细胞活性的潜在机制。方法：分别使用蒸馏水（对照）和白术水提物（白术治疗组）灌胃SD大鼠后，采集静脉血后分离其血清、过滤并分别命名为对照组血清（CON-S）和白术组血清（AM-S）。将胃癌SGC7901细胞分为对照组、10% AM-S组和20% AM-S组，其中两个AM-S组细胞分别在相应浓度的AM-S血清中培养24 h，对照组细胞用正常培养基培养相同时间，收取SGC7901细胞和上清液用于进一步分析。使用MTT法检测各组细胞活力，通过商业试剂盒测定乳酸脱氢酶（LDH）、丙二醛（MDA）和超氧化物歧化酶（SOD）的水平，采用ELISA试剂盒检测各组细胞中IL-6和TNF-α的含量，采用WB法评估各组细胞中PI3K-Akt-NF-κB信号通路相关蛋白的表达。结果：10% AM-S组和20% AM-S组的SGC7901胃癌细胞增殖活力相较于对照组分别降低48.9%和53.25%（P<0.05或P<0.01）；胃癌细胞上清液中，相较于对照组，10% AM-S组和20% AM-S组LDH水平分别升高29.25%和123%、SOD活性分别升高18%和54.60%、MDA水平分别降低27.8%和40.0%，IL-6水平分别降低15%和17.5%、TNF-α水平分别降低29.71%和40.16%（P<0.05或P<0.01）。相较于对照组，AM-S组中PI3K-Akt-NF-κB信号相关蛋白的水平显著下降（P<0.05或P<0.01）。结论：白术水提物可以通过抑制癌细胞增殖活力、促进凋亡、抑制肿瘤微环境中的促炎因子分泌以及改变细胞内的氧化应激水平等方式抑制胃癌，其机制可能是通过抑制PI3K-Akt-NF-κB通路来实现这些抗癌作用的。
ABSTRACT
@#[Abstract] Objective: To investigate the function and mechanism of ferroptosis in the radiation resistance of colorectal tumor-repopulating cells. Methods: Human colorectal tumor cells HCT116 (defined as Control cells) were cultured in two-dimensional normal conditions, and tumor regenerative cells with high tumorigenicity (defined as TRCs) were cultured and screened in three-dimensional fibrin soft gels by the mechanical force method. Both the control group and TRC group cells were exposed to X-rays with different doses (2, 4, 6, 8 Gy) and MTS and the clone formation assay were used tomeasure the cell viability rate and proliferation ability. After the Control cells and TRCs were treated with ferroptosis inducer (Erastin) and X-rays respectively, they were stained with C11-BODIPY reagent, and the lipid peroxidation level of the cells was observed and determined by confocal microscopy and flow cytometry. qPCR was used to determine the effects of Erastin and X-rays treatments on the expressions of ferroptosis-related genes glutathione peroxidase 4 (GPX4) and acyl-coenzyme A synthetase long-chain family member 4 (ACSL4) in the Control cells and TRCs; WB assay was performed to determine the effects on the expressions of ferroptosis-related proteins GPX4 and ACSL4. Results: Colorectal TRCs with high stemness were cultured and screened out from soft fibrin gels. After irradiation with different doses (2, 4, 6, 8 Gy) of X-rays, the viability rate, the clone sizeand the number of clones in the control group were significantly lower than those in the TRC group (all P<0.05). After the cells in the control group were irradiated with different doses of X-rays (4, 8 Gy) and treated with Erastin, the lipid peroxidation level of the cells in the X-ray treated group was significantly higher than that in the untreated group (P<0.05). The lipid peroxidation level of the cells in the Erastin-treated group was significantly higher than that in the DMSO-treated group (P<0.05). There was no statistical difference among all treatment subgroups in the TRC group (all P>0.05). The mechanism study indicated that compared with those in control cells, GPX4 and ACSL4 in TRCs under ferroptosis-inducing conditions (X-ray radiation and Erastin treatment) presented expressions that contributed more to radiation resistance, i.e., continued upregulation of GPX4 and downregulation of ACSL4 and their expressions were dependent on the doses of Erastin. Conclusion: Colorectal TRCs may resist ferroptosis through a high expression of GPX4 and a low expression of ACSL4, which in turn induces radiation resistance.