Cao Yang, Liang Haibin, Zhang Fei, Luan Zhou, Zhao Shuai, Wang Xu-An, Liu Shibo, Bao Runfa, Shu Yijun, Ma Qiang, Zhu Jian, Liu Yingbin
Department of General Surgery, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, P.R. China.
Institute of Biliary Tract Disease, Shanghai Jiao Tong University School of Medicine, Shanghai, 1665 Kongjiang Road, Shanghai, P.R. China.
J Exp Clin Cancer Res. 2016 Apr 16;35:68. doi: 10.1186/s13046-016-0346-7.
Prohibitin (PHB), a pleiotropic protein overexpressed in several tumor types, has been implicated in the regulation of cell proliferation, invasive migration and survival. However, PHB expression and its biological function in gallbladder cancer (GBC) remain largely unknown.
PHB and p-ERK protein expressions were determined in human GBC tissues by immunohistochemistry (IHC). The effects of PHB knockdown on GBC cell proliferation and invasiveness were evaluated using Cell Counting Kit-8 (CCK-8) cell viability, cell cycle analysis, transwell invasion and gelatin zymography assays. Subcutaneous xenograft and tail vein-lung metastasis tumor models in nude mice were employed to further substantiate the role of PHB in GBC progression.
PHB protein was overexpressed in GBC tissues and was significantly associated with histological grade, tumor stage and perineural invasion. Furthermore, PHB expression was negatively associated with overall survival in GBC patients. In vitro experimental studies demonstrated that the downregulation of PHB expression by lentivirus-mediated shRNA interference not only inhibited the ERK pathway activation but also reduced the proliferative and invasive capacities of GBC cells. Moreover, PD0325901, a specific inhibitor of MEK, markedly impaired PHB- mediated phosphorylation of ERK protein. IHC statistical analyses further validated that PHB expression was positively correlated with ERK protein phosphorylation levels in GBC tissue samples. In vivo, PHB depletion also resulted in dramatic reductions in the growth and metastasis of GBC cells.
Our findings demonstrate that PHB overexpression predicts poor survival in GBC patients. PHB could serve as a novel prognostic biomarker and a potential therapeutic target for GBCs.
抑制素（PHB）是一种在多种肿瘤类型中过表达的多效性蛋白，与细胞增殖、侵袭性迁移和存活的调节有关。然而，PHB在胆囊癌（GBC）中的表达及其生物学功能仍 largely未知。
通过免疫组织化学（IHC）检测人GBC组织中PHB和p-ERK蛋白的表达。使用细胞计数试剂盒-8（CCK-8）细胞活力、细胞周期分析、Transwell侵袭和明胶酶谱分析评估PHB敲低对GBC细胞增殖和侵袭性的影响。采用裸鼠皮下异种移植和尾静脉肺转移肿瘤模型进一步证实PHB在GBC进展中的作用。
PHB蛋白在GBC组织中过表达，且与组织学分级、肿瘤分期和神经周围浸润显著相关。此外，PHB表达与GBC患者的总生存期呈负相关。体外实验研究表明，慢病毒介导的shRNA干扰下调PHB表达不仅抑制ERK途径激活，还降低了GBC细胞的增殖和侵袭能力。此外，MEK的特异性抑制剂PD0325901显著损害PHB介导的ERK蛋白磷酸化。IHC统计分析进一步验证了GBC组织样本中PHB表达与ERK蛋白磷酸化水平呈正相关。在体内，PHB缺失也导致GBC细胞的生长和转移显著减少。
我们的研究结果表明，PHB过表达预示GBC患者预后不良。PHB可作为GBC的一种新型预后生物标志物和潜在治疗靶点。
