血浆 MAL 基因甲基化检测对于肺癌早期诊断的意义

目的：研究肺癌患者、肺结核患者及健康人群 T 淋巴细胞相关蛋白（T －lymphocyte maturation －asso-ciated protein，MAL）基因启动子区的甲基化状态，进一步探讨血浆 MAL 基因甲基化检测对于肺癌早期诊断及鉴别肺癌与肺结核疾病的意义。方法：采用甲基化特异性 PCR（methylation special PCR，MSP）方法，检测75例肺癌组织标本、癌旁组织标本和对应的血浆标本及58例肺结核组织标本及对应的血浆标本的 MAL 基因启动子区甲基化状态；同时检测30例正常人群的血浆标本 MAL 甲基化状态作为对照。结果：肺癌组织和癌旁组织中 MAL 基因甲基化发生率分别为78．7％（59／75）和2．7％（2／75），差别具有统计学意义（P ＜0．001）；肺癌和肺结核组织中 MAL 基因甲基化发生率分别为78．7％（59／75）和3．4％（2／58），差别具有统计学意义（P＜0．001）；肺癌患者与肺结核患者对应的血浆中 MAL 基因甲基化发生率分别73．3％（55／75）和1．7％（1／58），差别也具有统计学意义（P ＜0．001）。正常健康人群的血浆标本中未发现 MAL 基因甲基化改变；肺癌组和肺结核组分别与健康人群组比较，肺癌组明显高于健康人群（P ＜0．001），而肺结核组患者与健康人群比较无明显差异（P ＝0．47）。组织标本和血浆标本的检出率具有一致性（P ＞0．05）。根据病理类型、TNM分期、性别、吸烟史等对肺癌患者进行分组，各组之间均无明显差异（P ＞0．05）。结论：MSP 法检测血浆 MAL 基因甲基化状态，可以作为一种有潜力的肺癌早期诊断方法，对于鉴别肺癌和肺结核也有一定的帮助。

Plasma MAL gene methylation detection for early diagnosis of lung cancer

Objective:To study T lymphocyte related protein(T -lymphocyte maturation -associated protein, MAL)gene promoter region methylation status of patients with lung cancer,tuberculosis and healthy people and ex-plore the vaue of plasma MAL gene methylation detection for early diagnosis of lung cancer and tuberculosis.Meth-ods:By methylation specific PCR(methylation special PCR,MSP)detection method,to detect 75 cases of lung cancer tissue samples,tissue adjacent to carcinoma specimens and the corresponding plasma specimens and 58 cases of tu-berculosis tissue specimens and the corresponding plasma specimen MAL gene promoter region methylation status.Al-so detecting serum specimens of 30 cases of normal crowd MAL methylation status in comparison.Results:In lung cancer tissues and in tissue adjacent to carcinoma MAL gene methylation incidences were 78.7%(59 /75)and 2.7%(2 /75),the difference was statistically significant(P <0.001).MAL gene methylation in lung cancer and tuberculo-sis incidence was 78.7%(59 /75)and 3.4%(2 /58)(P <0.001).In the plasma of patients with lung cancer and pulmonary tuberculosis patients with corresponding MAL gene methylation rate 73.3%(55 /75)and 1.7%(1 /58) respectively(P <0.001).In normal plasma samples of healthy controls MAL gene methylation was not found.Lung cancer and tuberculosis group,respectively,compared with healthy group,lung cancer group was significantly higher than healthy people(P <0.001),and pulmonary tuberculosis patients compared with healthy people there was no ob-vious difference(P =0.47).Tissue samples and plasma samples detection rate was consistent(P >0.05).For patho-logical type,TNMstaging,gender,smoking history,there were no obvious difference between groups(P >0.05).Con-clusion:MSP method to detect the plasma MAL gene methylation status,can be used as a kind of lung cancer early di-agnosis method for differentiating lung cancer and tuberculosis.