Department of Biological Sciences and Biotechnology, University of Kurdistan, Iran.
Molecular and Cellular Biology Department, Islamic Azad University Tehran Medical Branch, Tehran, Iran.
J Cancer Res Ther. 2020 Oct-Dec;16(6):1412-1418. doi: 10.4103/jcrt.JCRT_675_19.
Cyclic nucleotide phosphodiesterase (PDE) enzymes are a large superfamily of enzymes that catalyze the conversion reaction of cyclic adenosine monophosphate (AMP) and cyclic guanosine monophosphate (GMP) to AMP and GMP, respectively. In some cancer cells, PDE-5 has been shown to be overexpressed in multiple human carcinomas. It seems that the inhibition of PDE-5 may has anticancer effects. Cisplatin is one of the prevalent chemo-agents to treat solid tumors. However, its clinical usefulness is hindered by dose-limiting toxicities, especially on the kidneys (nephrotoxicity) and ears (ototoxicity). In this study, the antitumor activity of the sildenafil as a PDE-5 inhibitor alone and in combination with cisplatin on human mammary adenocarcinomas and MCF-7 and MDA-MB-468 was assessed.
Sildenafil as PDE type 5 (PDE5) inhibitor is the drugs that we combined with the cisplatin (chemotherapeutic agent), in vitro. Human mammary adenocarcinomas and MCF-7 and MDA-MB-468 cell lines were cultured in standard conditions. At time point, following 24 h and 48 h incubation, the cell lines were treated by cisplatin in the presence/absence of sildenafil. Cell viability, apoptosis, and reactive oxygen species (ROS) were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, real-time polymerase chain reaction, and Western blot; and fluorimetric methods, respectively. Statistical analysis was performed using SPSS software SPSS (SPSS Inc., Chicago, IL, USA).
In MCF-7 cell line, following 24 h incubation, combinations of sildenafil with cisplatin (P < 0.001) showed decreased cell viability when compared to sildenafil and cisplatin alone. Moreover in MDA-MB-468 cell line, following 24 h incubation, data did not show any significant changes on cell viability when treated with cisplatin, in the presence or absence of sildenafil. However, following 48 h incubation, combinations of cisplatin with sildenafil (P < 0.001) were showed decreased cell viability when compared to cisplatin and sildenafil alone in both MCF-7 and MDA-MB-468 cell lines. Concerning the ROS production and apoptosis, data showed that both processes increase significantly in the presence of the sildenafil in comparison absent it.
Our data showed that the combination of sildenafil with cisplatin can improve cell toxicity and anticancer effect of cisplatin. And also sildenafil as a PDE-5 inhibitor could be used as additive treatment in combination with cisplatin to make a reduction in cisplatin dosage and its side effects.
环核苷酸磷酸二酯酶（PDE）酶是一个庞大的酶超家族，催化环腺苷酸（AMP）和环鸟苷酸（GMP）分别转化为 AMP 和 GMP 的反应。在一些癌细胞中，PDE-5 已被证明在多种人类癌中过度表达。似乎 PDE-5 的抑制可能具有抗癌作用。顺铂是治疗实体瘤的常用化疗药物之一。然而，其临床应用受到剂量限制毒性的限制，特别是对肾脏（肾毒性）和耳朵（耳毒性）。在这项研究中，我们评估了西地那非作为 PDE-5 抑制剂单独使用以及与顺铂联合治疗人乳腺腺癌和 MCF-7 和 MDA-MB-468 的抗肿瘤活性。
西地那非作为 PDE 型 5（PDE5）抑制剂是我们与顺铂（化疗药物）联合使用的药物，在体外。人乳腺腺癌和 MCF-7 和 MDA-MB-468 细胞系在标准条件下培养。在时间点，孵育 24 小时和 48 小时后，用顺铂处理细胞系，存在/不存在西地那非。使用 3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四唑溴盐测定法、实时聚合酶链反应和 Western blot；和荧光法分别测量细胞活力、细胞凋亡和活性氧（ROS）。使用 SPSS 软件 SPSS（芝加哥，IL，USA）进行统计分析。
在 MCF-7 细胞系中，孵育 24 小时后，与单独使用西地那非和顺铂相比，西地那非与顺铂的组合（P < 0.001）显示出降低的细胞活力。此外，在 MDA-MB-468 细胞系中，孵育 24 小时后，用顺铂处理时，数据显示细胞活力没有任何显著变化，无论是否存在西地那非。然而，孵育 48 小时后，与单独使用顺铂和西地那非相比，顺铂与西地那非的组合（P < 0.001）显示出降低的细胞活力在 MCF-7 和 MDA-MB-468 细胞系中均如此。关于 ROS 产生和细胞凋亡，数据表明，与不存在西地那非相比，这两个过程在存在西地那非的情况下显著增加。
我们的数据表明，西地那非与顺铂的联合使用可以提高顺铂的细胞毒性和抗癌作用。此外，西地那非作为 PDE-5 抑制剂可作为附加治疗与顺铂联合使用，以减少顺铂的剂量及其副作用。
