癌症化疗药物的致衰老作用及其导致的衰老相关炎症因子表达

Conventional cancer chemotherapy drugs induce cell senescence and senescence-associated inflammatory factors expression

目的化疗是癌症治疗中的主要手段之一,随着癌症患者生存率的提高和生存时间的延长,化疗药物对于病人的长期影响应该进行进一步的研究,本研究比较多种传统化疗药物对于细胞和小鼠的致衰老作用和衰老相关的炎症因子的表达情况。方法用CCK8方法对比11种不同作用机制的化疗药物对正常细胞和癌细胞的抑制浓度,检测作为细胞衰老的主要指标的β-半乳糖苷酶阳性细胞,选取7种化疗药物检测对衰老标志基因p21、p16及RB表达的影响及衰老相关炎症因子IL-6、TGF-β的表达情况。选取5种化疗药物在小鼠体内检测对肾脏组织中细胞衰老标志性基因以及血清中炎症因子表达的情况。结果我们发现在1/4半数活性抑制浓度(IC50)的作用下,11种药物中有8种在癌细胞中只造成约10%的细胞衰老,而在正常细胞中造成超过50%的细胞衰老。在选择的7种药物种,有3种、5种和5种药物在正常细胞中分别显著提高了p16、Rb和p21的表达,而在癌细胞中有这种作用的药物分别只有1种、4种和3种,且有6种药物显著抑制了p16的表达。多西他赛处理显著提高了正常细胞的IL-6表达。多柔比星、硼替佐米和甲氨喋呤提高了正常细胞中TGF-β的表达。在小鼠肾脏组织中,5种化疗药物处理后都有明显的衰老细胞增多,硼替佐米显著提高了血清中IL-6的水平,甲氨喋呤和环磷酰胺显著提高了血清中TGF-β的水平。结论化疗药物对正常细胞产生明显的致衰老作用,在特定癌症的用药中应考虑其长期的衰老相关影响。

Chemotherapy is one of the main methods in cancer treatment, but the side effects of chemotherapy drugs still need further clarification. Here, to investigate the senescent effect of traditional cancer chemotherapy drugs, we employed CCK8 method to compare the inhibitory concentrations of 11 chemotherapeutic drugs with different mechanisms of action on normal mouse embryonic fibroblast cells(MEF) and T47 D breast cancer cells. The percentage of senescence associated β-galactosidase(SA-β-Gal) positive cells were employed as the main indicator of cell senescence. Seven selected chemotherapeutic drugs were used to treat MEF and T47 D cells, and the expression of senescence marker genes p16, RB, p21 and the expression of senescence-related inflammatory factors IL-6 and TGF-β were examined by quantitative PCR. Five chemotherapeutic drugs were selected to treat mice, and the cellular senescence effect in kidney tissues and on the level of inflammatory factors in serum were measured.With a concentration of a quarter of IC50, 8 out of 11 drugs caused about 10% cell senescence in tumorcells, but caused more than 50% cell senescence innormal cells. In 7 selected drugs, 3, 5, and 5 drugssignificantly promoted expression of p16, Rb and p21 in normal cells, respectively. In cancer cells, only 1, 4 and 3 drugs did the same, and 6 drugs repressed theexpression of p16. Docetaxel in normal cells increased the expression of IL-6. Doxrubincin, bortezomib andmethotrexate increased TGF-β expression in normal cells. In mouse kidney tissues, all 5 tested drugs leadedobvious increase of cellular senescence. Bortezomib significantly increased IL-6 level in mouse serum, andmethotrexate and cyclophosphamide increased TGF-β level in mouse serum. Taken together, chemotherapeuticagents exert significant senescent effects on normal cells, and their long-term senescence-related effects should beconsidered in the administration of drugs for specific cancers.