己酮可可碱使宫颈癌细胞对阿霉素敏感，诱导细胞凋亡增加，衰老减少。

Sensitization of cervix cancer cells to Adriamycin by Pentoxifylline induces an increase in apoptosis and decrease senescence.

机构信息

División de Inmunología, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Sierra Mojada 800, Colonia Independencia, Guadalajara, Jalisco, CP 44340, México.

出版信息

Mol Cancer. 2010 May 19;9:114. doi: 10.1186/1476-4598-9-114.

DOI:10.1186/1476-4598-9-114

PMID:20482878

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2890603/

Abstract

BACKGROUND

Chemotherapeutic drugs like Adriamycin (ADR) induces apoptosis or senescence in cancer cells but these cells often develop resistance and generate responses of short duration or complete failure. The methylxantine drug Pentoxifylline (PTX) used routinely in the clinics setting for circulatory diseases has been recently described to have antitumor properties. We evaluated whether pretreatment with PTX modifies apoptosis and senescence induced by ADR in cervix cancer cells.

METHODS

HeLa (HPV 18+), SiHa (HPV 16+) cervix cancer cells and non-tumorigenic immortalized HaCaT cells (control) were treated with PTX, ADR or PTX + ADR. The cellular toxicity of PTX and survival fraction were determinated by WST-1 and clonogenic assay respectively. Apoptosis, caspase activation and ADR efflux rate were measured by flow cytometry, senescence by microscopy. IkappaBalpha and DNA fragmentation were determinated by ELISA. Proapoptotic, antiapoptotic and senescence genes, as well as HPV-E6/E7 mRNA expression, were detected by time real RT-PCR. p53 protein levels were assayed by Western blot.

RESULTS

PTX is toxic (WST-1), affects survival (clonogenic assay) and induces apoptosis in cervix cancer cells. Additionally, the combination of this drug with ADR diminished the survival fraction and significantly increased apoptosis of HeLa and SiHa cervix cancer cells. Treatments were less effective in HaCaT cells. We found caspase participation in the induction of apoptosis by PTX, ADR or its combination. Surprisingly, in spite of the antitumor activity displayed by PTX, our results indicate that methylxantine, per se does not induce senescence; however it inhibits senescence induced by ADR and at the same time increases apoptosis. PTX elevates IkappaBalpha levels. Such sensitization is achieved through the up-regulation of proapoptotic factors such as caspase and bcl family gene expression. PTX and PTX + ADR also decrease E6 and E7 expression in SiHa cells, but not in HeLa cells. p53 was detected only in SiHa cells treated with ADR.

CONCLUSION

PTX is a good inducer of apoptosis but does not induce senescence. Furthermore, PTX reduced the ADR-induced senescence and increased apoptosis in cervix cancer cells.

摘要

背景

阿霉素（ADR）等化疗药物可诱导癌细胞凋亡或衰老，但这些细胞常产生耐药性，导致反应持续时间短或完全失败。在临床上常用于治疗循环系统疾病的甲基黄嘌呤药物己酮可可碱（PTX）最近被描述具有抗肿瘤特性。我们评估了 PTX 预处理是否会改变宫颈癌细胞中 ADR 诱导的凋亡和衰老。

方法

用 PTX、ADR 或 PTX+ADR 处理 HeLa（HPV18+）、SiHa（HPV16+）宫颈癌细胞和非致瘤性永生化 HaCaT 细胞（对照）。用 WST-1 测定 PTX 的细胞毒性和存活分数，用克隆形成试验分别测定 ADRE 流出率。用流式细胞术测定细胞凋亡、半胱氨酸蛋白酶激活和 ADR 外排率，用显微镜测定衰老。用 ELISA 测定 IkappaBalpha 和 DNA 片段化。用时间实时 RT-PCR 检测促凋亡、抗凋亡和衰老基因以及 HPV-E6/E7mRNA 表达。用 Western blot 测定 p53 蛋白水平。

结果

PTX 有毒性（WST-1），影响生存（克隆形成试验），并诱导宫颈癌细胞凋亡。此外，该药物与 ADR 联合使用可降低 HeLa 和 SiHa 宫颈癌细胞的存活分数，并显著增加细胞凋亡。该治疗方案对 HaCaT 细胞的效果较差。我们发现 caspase 参与了 PTX、ADR 或其联合诱导的细胞凋亡。令人惊讶的是，尽管 PTX 表现出抗肿瘤活性，但我们的结果表明，甲基黄嘌呤本身不会诱导衰老；然而，它抑制了 ADR 诱导的衰老，同时增加了细胞凋亡。PTX 升高了 IkappaBalpha 水平。这种增敏作用是通过上调促凋亡因子如半胱氨酸蛋白酶和 bcl 家族基因表达来实现的。PTX 和 PTX+ADR 还降低了 SiHa 细胞中 E6 和 E7 的表达，但在 HeLa 细胞中没有。ADR 处理的 SiHa 细胞中仅检测到 p53。