鼻咽癌组织RASSF1A基因的表达

Expression of RASSF1A gene in nasopharyngeal carcinoma

目的探讨RASSF1A基因在鼻咽癌发病过程中的作用。方法采用逆转录-聚合酶链技术在4种鼻咽癌细胞株、32例鼻咽癌组织和16例正常鼻咽部组织中检测RASSF1A基因的表达,并分析鼻咽癌组织在3p21.3 D3S4604微卫星多态性位点的等位基因杂合性丢失状况。结果RASSF1A基因在4种鼻咽癌细胞株中低表达,32例鼻咽癌组织的RASSF1A基因表达显著低于16例正常鼻咽部组织(P=0.001);43.75%(14/32)的鼻咽癌组织在3p21.3 D3S4604位点发生了杂合性丢失。鼻咽癌RASSF1A基因表达与性别、年龄、颈部淋巴结转移、TNM临床分期、D3S4604位点杂合性丢失和血清EB病毒VCA/IgA抗体滴度无显著相关性,但伴远处转移的鼻咽癌组织的RASSF1A表达显著低于无远处转移的鼻咽癌(P=0.014)。结论RASSF1A基因的表达下调可能是鼻咽癌发病过程中的晚期事件,3p21区域可能还存在与鼻咽癌发生密切相关的抑瘤基因。

Objective To investigate the role of RASSF1A gene in the pathogenesis of nasopharyngeal carcinoma (NPC). Methods RASSF1A gene expression was examined by semi-quantitative reverse transcriptional-polymerase chain reaction (RT-PCR) in 32 specimens of poorly differentiated squamous cell carcinoma from patients with primary NPC, 16 specimens of histologically normal nasopharyngeal epithelia, and 4 NPC cell lines (CNE1, CNE2, HNE1, HNE2). The loss of heterozy-gosity (LOH) on chromosome 3p21.3 was detected using D3S4604 microsatellite marker in NPC. Results Reduction in the expression level of RASSF1A was significantly lower in NPC than in normal nasopharyngeal epithelium(P=0.001). Allelic delection (LOH) on 3p21.3 was assessed in 43.75% of the NPC specimens. However, there was no evidence to demonstrate the relationship between RASSF1A expression and the patient's age, gender, and some clinical features such as lymph node metas-tasis, TNM stage and serum titer of EBV (VCA/IgA) antibody (P>0.05). The expression of RASSF1A was reduced in NPC specimens from NPC patients with distant metastasis compared with that of patients without distant metastasis (P=0.014). Conclusion Down-regulated RASSF1A gene expression might be an event in the later stages of the tumorigenesis of NPC, and the 3p21 region may contain tumor suppressor genes that are could be deeply involved in the tumorigenesis of NPC.