Department of Biological Sciences, Binghamton University, Binghamton, NY, USA.
BJU Int. 2012 Mar;109(6):949-58. doi: 10.1111/j.1464-410X.2011.10408.x. Epub 2011 Aug 26.
To investigate the effect and molecular mechanisms of action of Vitamin D(3) (VD(3) ) as a neo-adjunctive agent before cryosurgery in an effort to increase treatment efficacy for prostate cancer (CaP). To eliminate the potential for disease recurrence that exists at the periphery of the freeze lesion, where temperatures may be insufficient to destroy both androgen-sensitive (AS) and androgen-insensitive (AI) CaP.
Human CaP cells, LNCaP, were each genetically altered to express the AS and AI phenotypes and subjected to VD(3) treatment and freezing in an in vitro and tissue-engineered model. Cell viability, caspase inhibitor and western blot studies were used to determine the basis of the different responses of AI and AS cells to VD(3) cryosensitization.
VD(3) was found to be a highly effective cryosensitizer, resulting in a >50% overall increase in cell death after -15 °C freezing. Fluorescence microscopy, western blot analysis and caspase protease assays confirmed that the increased activation of apoptosis was modulated through a mitochondrial-mediated pathway. Caspase inhibition studies showed that apoptosis played an integral role in cell death, with VD(3) cryosensitivation-induced apoptotic events responsible for >30% of the overall cell death after -15 °C freezing.
The present study suggests that the use of VD(3) as a cryosensitizer increases cryoablation efficacy through the increased activity of apoptosis as well as through necrosis. The data show that through VD(3) treatment the overall level of AI CaP cell tolerance to freezing is reduced to a level similar to that of AS CaP. VD(3) pre-treatment in conjunction with cryoablation may increase treatment efficacy and reduce disease recurrence for CaP patients.
研究维生素 D(3)（VD(3)）作为冷冻手术前的新型辅助剂的作用效果和作用机制，以提高前列腺癌（CaP）的治疗效果。消除冷冻损伤边缘可能存在的疾病复发的潜在风险，因为在那里的温度可能不足以破坏雄激素敏感（AS）和雄激素不敏感（AI）CaP。
将人 CaP 细胞 LNCaP 分别进行基因改造以表达 AS 和 AI 表型，并在体外和组织工程模型中进行 VD(3)治疗和冷冻。细胞活力、半胱氨酸天冬氨酸蛋白酶抑制剂和 Western blot 研究用于确定 AI 和 AS 细胞对 VD(3)冷冻增敏的不同反应的基础。
发现 VD(3)是一种非常有效的冷冻增敏剂，在-15°C 冷冻后导致细胞死亡总体增加超过 50%。荧光显微镜、Western blot 分析和半胱氨酸天冬氨酸蛋白酶测定证实，凋亡的激活增加是通过线粒体介导的途径进行调节的。半胱氨酸天冬氨酸蛋白酶抑制剂研究表明，凋亡在细胞死亡中起着重要作用，VD(3)冷冻增敏诱导的凋亡事件在-15°C 冷冻后导致超过 30%的总体细胞死亡。
本研究表明，使用 VD(3)作为冷冻增敏剂可通过增加细胞凋亡的活性以及通过坏死来提高冷冻消融的疗效。数据表明，通过 VD(3)治疗，AI CaP 细胞对冷冻的整体耐受水平降低到与 AS CaP 相似的水平。VD(3)预处理联合冷冻消融可能会提高 CaP 患者的治疗效果并降低疾病复发率。
