Abstract：
This study investigated whether melatonin (Mel) would promote cisplatin to suppress the proliferation and growth of bladder cancer (BC) cells by inhibiting cellular prion protein (PrPC)-mediated cell stress and cell proliferation signaling. An immunohistochemical staining of tissue arrays from BC patients demonstrated that the PrPC expression was significantly upregulated from stage I to III BC (p < 0.0001). The BC cellline of T24 was categorized into G1 (T24), G2 (T24 + Mel/100 μM), G3 (T24+cisplatin/6 μM), G4 (PrPC overexpression in T24 (i.e., PrPC-OE-T24)), G5 (PrPC-OE-T24+Mel), and G6 (PrPC-OE-T24+cisplatin). When compared with a human uroepithelial cell line (SV-HUC-1), the cellular viability/wound healing ability/migration rate were significantly increased in T24 cells (G1) and further significantly increased in PrPC-OE-T24 cells (G4); and they were suppressed in Mel (G2/G5) or cisplatin (G3/G6) treatment (all p < 0.0001). Additionally, the protein expressions of cell proliferation (PI3K/p-Akt/p-m-TOR/MMP-9/PrPC), cell cycle/mitochondrial functional integrity (cyclin-D1/clyclin-E1/ckd2/ckd4/mitochondrial-cytochrome-C/PINK1), and cell stress (RAS/c-RAF/p-MEK1/2, p-ERK1/2) markers showed a similar pattern of cell viability among the groups (all p < 0.001). After the BC cell line of UMUC3 was implanted into nude mouse backs, by day 28 mthe BC weight/volume and the cellular levels of PrPC/MMP-2/MMP-9 were significantly, gradually reduced from groups one to four (all p < 0.0001). The protein expressions of cell proliferation (PI3K/p-Akt/p-m-TOR/MMP-9/PrPC), cell cycle/mitophagy (cyclin-D1/clyclin-E1/ckd2/ckd4/PINK1), and cell stress (RAS/c-RAF/p-MEK1,2/p-ERK1,2) signaling were significantly, progressively reduced from groups one to four, whereas the protein expressions of apoptotic (Mit-Bax/cleaved-caspase-3/cleaved-PARP) and oxidative stress/mitochondrial damaged (NOX-1/NOX-2/cytosolic-cytochrome-C/p-DRP1) markers expressed an opposite pattern of cell proliferation signaling among the groups (all p < 0.0001). Mel-cisplatin suppressed BC cell growth/proliferation via inhibiting the PrPC in upregulating the cell proliferation/cell stress/cell cycle signaling.
摘要：
这项研究调查了褪黑激素（Mel）是否会通过抑制细胞朊病毒蛋白（PrPC）介导的细胞应激和细胞增殖信号传导来促进顺铂抑制膀胱癌（BC）细胞的增殖和生长。来自BC患者的组织阵列的免疫组织化学染色表明,PrPC表达从I期至III期BC显著上调(p<0.0001)。T24的BC细胞系分为G1（T24），G2(T24+Mel/100μM),G3（T24+顺铂/6μM），G4（T24中的PrPC过表达（即，PrPC-OE-T24)),G5(PrPC-OE-T24+Mel),和G6(PrPC-OE-T24+顺铂)。与人尿路上皮细胞系（SV-HUC-1）相比，在T24细胞（G1）中，细胞活力/伤口愈合能力/迁移率显着增加，在PrPC-OE-T24细胞（G4）中进一步显着增加；并且在Mel（G2/G5）或顺铂（G3/G6）治疗中受到抑制（均p<0.0001）。此外,细胞增殖的蛋白表达(PI3K/p-Akt/p-m-TOR/MMP-9/PrPC),细胞周期/线粒体功能完整性（cyclin-D1/clyclin-E1/ckd2/ckd4/线粒体-细胞色素-C/PINK1），和细胞应激（RAS/c-RAF/p-MEK1/2，p-ERK1/2）标记物显示各组之间相似的细胞活力模式（所有p<0.001）。将UMUC3的BC细胞系植入裸鼠背部后，到第28天，BC重量/体积和PrPC/MMP-2/MMP-9的细胞水平显着，从第1组到第4组逐渐降低（所有p<0.0001）。细胞增殖蛋白(PI3K/p-Akt/p-m-TOR/MMP-9/PrPC)的表达,细胞周期/线粒体自噬（细胞周期蛋白-D1/clyclin-E1/ckd2/ckd4/PINK1），细胞应激(RAS/c-RAF/p-MEK1,2/p-ERK1,2)从第一组逐渐减少到第四组，而凋亡(Mit-Bax/cleaved-caspase-3/cleaved-PARP)和氧化应激/线粒体损伤(NOX-1/NOX-2/细胞溶质-细胞色素-C/p-DRP1)标记的蛋白表达在各组间表达相反的细胞增殖信号模式(所有p<0.0001)。Mel-顺铂通过抑制PrPC上调细胞增殖/细胞应激/细胞周期信号传导来抑制BC细胞生长/增殖。
