PDF(Pubmed)
Abstract：
TRPV6 calcium channel is a prospective target in prostate cancer (PCa) since it is not expressed in healthy prostate while its expression increases during cancer progression. Despite the role of TRPV6 in PCa cell survival and apoptotic resistance has been already established, no reliable tool to target TRPV6 channel in vivo and thus to reduce tumor burden is known to date. Here we report the generation of mouse monoclonal antibody mAb82 raised against extracellular epitope of the pore region of the channel. mAb82 inhibited TRPV6 currents by 90% at 24 µg/ml in a dose-dependent manner while decreasing store-operated calcium entry to 56% at only 2.4 µg/ml. mAb82 decreased PCa survival rate in vitro by 71% at 12 µg/ml via inducing cell death through the apoptosis cascade via activation of the protease calpain, following bax activation, mitochondria enlargement, and loss of cristae, Cyt C release, pro-caspase 9 cleavage with the subsequent activation of caspases 3/7. In vivo, mice bearing either PC3Mtrpv6+/+ or PC3Mtrpv6-/-+pTRPV6 tumors were successfully treated with mAb82 at the dose as low as 100 µg/kg resulting in a significant reduction tumor growth by 31% and 90%, respectively. The survival rate was markedly improved by 3.5 times in mice treated with mAb82 in PC3Mtrpv6+/+ tumor group and completely restored in PC3Mtrpv6-/-+pTRPV6 tumor group. mAb82 showed a TRPV6-expression dependent organ distribution and virtually no toxicity in the same way as mAbAU1, a control antibody of the same Ig2a isotype. Overall, our data demonstrate for the first time the use of an anti-TRPV6 monoclonal antibody in vitro and in vivo in the treatment of the TRPV6-expressing PCa tumors.
摘要：
TRPV6钙通道是前列腺癌(PCa)中的预期靶标,因为其在健康前列腺中不表达,而其表达在癌症进展期间增加。尽管TRPV6在PCa细胞存活和凋亡抵抗中的作用已经确立，迄今为止,尚无可靠的工具在体内靶向TRPV6通道,从而减轻肿瘤负荷.在这里，我们报告了针对通道孔区域的细胞外表位产生的小鼠单克隆抗体mAb82的产生。mAb82以剂量依赖性方式在24µg/ml时将TRPV6电流抑制了90％，而在仅2.4µg/ml时将存储操作的钙进入减少到56％。mAb82在12µg/ml时通过蛋白酶钙蛋白酶的激活通过凋亡级联诱导细胞死亡，使PCa的体外存活率降低了71％，在bax激活之后，线粒体增大,和cr的损失，CytC释放,pro-caspase9裂解，随后激活caspase3/7。在体内,携带PC3Mtrpv6+/+或PC3Mtrpv6-/-+pTRPV6肿瘤的小鼠用剂量低至100µg/kg的mAb82成功治疗，导致肿瘤生长显著减少31%和90%，分别。在PC3Mtrpv6+/+肿瘤组中，mAb82治疗的小鼠的存活率显着提高了3.5倍，在PC3Mtrpv6-/-pTRPV6肿瘤组中完全恢复。mAb82以与mAbAU1相同的方式显示TRPV6表达依赖性器官分布和几乎无毒性,mAbAU1是相同Ig2a同种型的对照抗体。总的来说,我们的数据首次证明了在体内和体外使用抗TRPV6单克隆抗体治疗表达TRPV6的PCa肿瘤.
