Liu Ai-Yun, Liu Ming-Na, Pei Feng-Hua, Chen Jing, Wang Xin-Hong, Liu Dan, Du Ya-Ju, Liu Bing-Rong
Department of Gastroenterology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.
Mol Med Rep. 2015 Sep;12(3):3487-3493. doi: 10.3892/mmr.2015.3881. Epub 2015 Jun 3.
The nitrogen permease regulator‑like‑2 (NPRL2) gene is a candidate tumor suppressor gene, which has been identified in the 3p21.3 human chromosome region. Decreased expression levels of NPRL2 have been observed in colorectal cancer (CRC) tissues, however, the function of NPRL2 in CRC progression remains to be fully elucidated. The present study investigated the biological characteristics of the HCT116 and HT29 CRC cell lines overexpressing exogenous NPRL2. NPRL2 recombinant lentiviral vectors were also constructed and transfected in the present study. Cell growth was determined using a Cell Counting Kit‑8 assay and a colony formation assay. The cell cycle and rate of apoptosis were assessed using flow cytometric analysis. Transwell assays were used to evaluate cell invasion. The protein expression of phosphorylated (p)‑AKT and caspase 3, B‑cell lymphoma 2 (Bcl2) and Bcl‑2‑associated X protein apoptosis‑associated genes, were detected using western blotting. The results revealed that NPRL2 overexpression inhibited cell growth, induced cell cycle G1 phase arrest, promoted apoptosis and inhibited invasion in the two human CRC cell lines. Furthermore, the protein expression levels of p‑AKT and Bcl2 were significantly reduced in the NPRL2‑transfected HCT116 and HT29 cells, compared with the mock‑transfected group and control group, while the protein expression of caspase‑3 was increased. Therefore, NPRL2 acted as a functional tumor suppressor in the CRC cell lines.
氮通透酶调节因子样2（NPRL2）基因是一种候选肿瘤抑制基因，已在人类3号染色体区域3p21.3中被鉴定出来。在结直肠癌（CRC）组织中已观察到NPRL2表达水平降低，然而，NPRL2在CRC进展中的功能仍有待充分阐明。本研究调查了过表达外源性NPRL2的HCT116和HT29 CRC细胞系的生物学特性。本研究还构建并转染了NPRL2重组慢病毒载体。使用细胞计数试剂盒-8检测法和集落形成检测法测定细胞生长。使用流式细胞术分析评估细胞周期和凋亡率。采用Transwell检测法评估细胞侵袭。使用蛋白质印迹法检测磷酸化（p）-AKT、半胱天冬酶3、B细胞淋巴瘤2（Bcl2）和Bcl-2相关X蛋白凋亡相关基因的蛋白质表达。结果显示，NPRL2过表达抑制了两种人CRC细胞系的细胞生长，诱导细胞周期G1期阻滞，促进凋亡并抑制侵袭。此外，与mock转染组和对照组相比，NPRL2转染的HCT116和HT29细胞中p-AKT和Bcl2的蛋白质表达水平显著降低，而半胱天冬酶-3的蛋白质表达增加。因此，NPRL2在CRC细胞系中发挥功能性肿瘤抑制作用。
