Xu Leilei, Xia Chao, Xue Bingchuan, Sheng Fei, Xiong Jin, Wang Shoufeng
Department of Orthopedic Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road 321, Nanjing 210008, China.
J Bone Oncol. 2018 Mar 6;12:23-26. doi: 10.1016/j.jbo.2018.03.001. eCollection 2018 Sep.
Previous studies showed that genetic variant rs145204276 in the promoter region of GAS5 was associated with the development of human cancer including colorectal cancer and hepatocellular cancer. This study aimed to investigate the role of rs145204276 in the development of osteosarcoma (OS).
132 OS patients and 1270 healthy controls were recruited for the genotyping analysis of rs145204276. Promoter methylation level of GAS5 was determined for all patients. The tumor tissues and the adjacent normal tissue were collected from 42 patients during surgery and the relative expression of GAS5 was then quantified by Real-time PCR. The Chi-square test was used to determine the difference of genotype and allele frequency between the patients and the controls. The gene expression and the percentage of methylation alleles were compared among different genotypes of rs145204276 with One-way ANOVA test.
Compared with the controls, patients were found to have significantly lower rate of genotype del/del (7.6% vs. 8.7%, p = 0.024). The frequency of allele del was significantly lower in the patients than in the controls (23.5% vs. 30.1%, p = 0.021). Compared with than patients with genotype ins/ins, those with genotype del/del had remarkably higher expression of GAS5 (0.0033 ± 0.0019 vs. 0.0018 ± 0.0006, p < 0.001). Patients with genotype del/del were found to have obviously hypermethylation at the 7th CpG site as compared with those with genotype ins/ins (38.7% ± 21.1% vs. 20.5% ± 8.2%, p < 0.001).
The genetic variant rs145204276 is functionally associated with the susceptibility of OS, which can function as a protective factor in the incidence of OS possibly through the regulation of GAS5.
先前的研究表明，生长停滞特异性转录本5（GAS5）启动子区域的基因变异rs145204276与包括结直肠癌和肝细胞癌在内的人类癌症的发生发展相关。本研究旨在探讨rs145204276在骨肉瘤（OS）发生发展中的作用。
招募132例OS患者和1270例健康对照者进行rs145204276的基因分型分析。测定所有患者GAS5的启动子甲基化水平。手术中从42例患者收集肿瘤组织和癌旁正常组织，然后通过实时定量聚合酶链反应（Real-time PCR）定量GAS5的相对表达量。采用卡方检验确定患者与对照者之间基因型和等位基因频率的差异。采用单因素方差分析比较rs145204276不同基因型之间的基因表达和甲基化等位基因百分比。
与对照者相比，患者中基因型del/del的比例显著更低（7.6%对8.7%，p = 0.024）。患者中等位基因del的频率显著低于对照者（23.5%对30.1%，p = 0.021）。与基因型ins/ins的患者相比，基因型del/del的患者GAS5表达显著更高（0.0033±0.0019对0.0018±0.0006，p < 0.001）。与基因型ins/ins的患者相比，基因型del/del的患者在第7个CpG位点明显存在高甲基化（38.7%±21.1%对20.5%±8.2%，p < 0.001）。
基因变异rs145204276与OS易感性在功能上相关，其可能通过调控GAS5在OS发病中发挥保护作用。
