原发性肺癌患者结核分枝杆菌感染调查及Notch信号通路表达分析

An investigation of Mycobacterium tuberculosis infection and expression of the Notch signaling pathway in patients with primary lung cancer

摘要:

目的 探究原发性肺癌患者结核分枝杆菌（Mycobacterium tuberculosis，MTB）感染调查及Notch信号通路表达情况。方法 选取2022年1月至2022年6月在重庆大学附属肿瘤医院接受根治术治疗的96例原发性肺癌患者为研究对象，采用原位分子杂交技术和抗酸染色法对肺组织的MTB及其L型进行检测，药敏试验分析其耐药性，测序鉴定靶基因位点突变情况，蛋白印迹法检测肺组织Notch1、Notch2和Notch3蛋白表达。结果 96例原发性肺癌组织标本MTB-L型阳性率为38.54%（37/96），阳性患者痰标本共分离出MTB-L菌株68株；分离MTB-L型菌株对一线抗结核药物耐药率为60.29%（41/68），其中对异烟肼、链霉素、利福平及乙胺丁醇联合使用耐药率最高（22.06%）；分离MTB-L型菌株对二线抗结核药物耐药率为36.76%（25/68），其中对氧氟沙星单一用药耐药率最高（14.70%）；MTB-L型菌株药物靶基因突变率前3位分别为异烟肼靶基因katG S315T（45.58%）、链霉素靶基因rpsL K43R（42.65%）、利福平靶基因rpoB S450L（20.59%）；MTB-L型感染阳性患者肺组织中Notch1、Notch2、Notch3蛋白相对表达量高于MTB-L型阴性者（P<0.05）。结论 原发性肺癌患者MTB感染类型主要为L型，其耐药形势严峻，合并MTB-L型感染患者存在Notch信号通路的异常激活。

Abstract:

Objective To explore Mycobacterium tuberculosis（MTB） infection and the expression of the Notch signaling pathway in patients with primary lung cancer.Methods A total of 96 patients with primary lung cancer who underwent radical surgery at Chongqing University Cancer Hospital between January 2022 and June 2022 were enrolled as research subjects. MTB and its L-forms in the lung tissue were detected using in situ molecular hybridization and acid-fast staining. Drug resistance was analyzed using a drug susceptibility test. Mutations at the sites of target genes were identified using sequencing. The expressions of Notch1，Notch2 and Notch3 proteins in the lung tissue were determined using Western blot.Results Of the 96 patients with primary lung cancer，the positive rate of MTB-L forms was 38.54%（37/96），with 68 MTB-L strains isolated from the sputum samples of the positive patients. The resistance rate of the isolated MTB-L strains to first-line anti-tuberculosis drugs was 60.29%（41/68），with the highest drug resistance rate of 22.06% for the combination of isoniazid，streptomycin，rifampicin，and ethambutol. The resistance rate of the isolated MTB-L strains to second-line anti-tuberculosis drugs was 36.76%（25/68），with the highest drug resistance rate of 14.70% for ofloxacin alone. The target genes with the top three mutation rates at the drug sites of the MTB-L strains were isoniazid katG S315T（45.58%），streptomycin rpsL K43R（42.65%），and rifampicin rpoB S450L（20.59%）. The relative expression levels of Notch1，Notch2，and Notch3 proteins in the lung tissue of patients with positive MTB-L infections were higher than those in the lung tissue of patients with negative MTB-L infections（P<0.05）.Conclusion MTB infection in patients with primary lung cancer is mainly caused by MTB L-forms，and drug resistance is severe. Abnormal activation of the Notch signaling pathway is observed in patients with MTB-L infection.