Zhao Zijin, Xiao Songhua, Yuan Xianrui, Yuan Jian, Zhang Chi, Li Haoyu, Su Jun, Wang Xiangyu, Liu Qing
Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Institute of Skull Base Surgery and Neuro-oncology at Hunan, Changsha, China.
J Cancer. 2017 Aug 25;8(15):2924-2932. doi: 10.7150/jca.20277. eCollection 2017.
AHNAK is originally identified as a giant protein based on the estimated size of approximately 700 kDa. The aim of this study is to identify the role of AHNAK in the pathogenesis of glioma.
We tested AHNAK mRNA level in a panel of six human glioma cell lines, and in 30 cases of normal brain tissues and 73 cases of glioma tissue samples using a qRT-PCR method. Further, we analyzed the relationship of AHNAK expression with clinicopathological characteristics in glioma patients. Meanwhile, we analyzed the relationship of expression of AHNAK and survival of glioma patients in survival analyses. Then, , we analyzed the biological effects of AHNAK in glioma cell lines (U87 and U251) including proliferation assay, cell transwell assay, and apoptosis. And in vivo, we examined the effects of AHNAK on tumor growth using xenograft model of human glioma cells in nude mice. Then we examined the expression of Ki-67-positive cells in these tumors.
We found that the mRNA levels of AHNAK were down-regulated in 4 of 6 human glioma cell lines, especially in U87 and U251 cell lines. Meanwhile, in glioma patients, a negative correlation was found between the expression of AHNAK and the glioma histopathology. And a low expression of AHNAK was a significant and independent prognostic factor for poor survival of glioma patients. Through over expression of AHNAK in both of U87 and U251, we demonstrated that overexpression of AHNAK could inhibit glioma cell proliferation and invasion, induce apoptosis, and inhibit in vivo glioma tumor growth and ki-67 expression.
The AHNAK acts as a potential tumor suppressor. Our study provides a preclinical basis for developing AHNAK as a reliable clinical prognostic indicator for glioma patients, and a new biomarker for treatment response, and a potentially therapeutic target in glioma management options.
AHNAK最初是作为一种巨型蛋白被鉴定出来的，估计大小约为700 kDa。本研究的目的是确定AHNAK在胶质瘤发病机制中的作用。
我们使用qRT-PCR方法检测了6种人类胶质瘤细胞系、30例正常脑组织和73例胶质瘤组织样本中的AHNAK mRNA水平。此外，我们分析了AHNAK表达与胶质瘤患者临床病理特征之间的关系。同时，在生存分析中，我们分析了AHNAK表达与胶质瘤患者生存之间的关系。然后，我们分析了AHNAK在胶质瘤细胞系（U87和U251）中的生物学效应，包括增殖测定、细胞Transwell测定和凋亡分析。在体内，我们使用人胶质瘤细胞裸鼠异种移植模型研究了AHNAK对肿瘤生长的影响。然后我们检测了这些肿瘤中Ki-67阳性细胞的表达。
我们发现6种人类胶质瘤细胞系中有4种的AHNAK mRNA水平下调，尤其是在U87和U251细胞系中。同时，在胶质瘤患者中，发现AHNAK表达与胶质瘤组织病理学之间呈负相关。AHNAK低表达是胶质瘤患者生存不良的一个显著且独立的预后因素。通过在U87和U251中过表达AHNAK，我们证明AHNAK过表达可抑制胶质瘤细胞增殖和侵袭，诱导凋亡，并抑制体内胶质瘤肿瘤生长和Ki-67表达。
AHNAK作为一种潜在的肿瘤抑制因子。我们的研究为将AHNAK开发为胶质瘤患者可靠的临床预后指标、治疗反应的新生物标志物以及胶质瘤治疗选择中的潜在治疗靶点提供了临床前依据。
