恶性增殖和浸润性生长相关分子变化在胶质瘤不同病理学分型中的差异

Differences of malignant proliferation and infiltrating growth related molecular changes in different pathological types of glioma

目的探讨细胞周期改变和细胞迁移及浸润性生长生物学进程和相关遗传学变化在各级别和各分子亚型胶质瘤中的差异。方法收集中国脑胶质瘤数据库中WHOⅡ-Ⅳ级的胶质瘤组织标本300例，分别提取RNA和DNA。利用Sanger测序检测PTEN、p53及端粒酶逆转录酶（TERT）启动子的突变情况，从全基因组RNA微阵列表达谱中调取MET和基质金属蛋白酶9（MMP-9）的表达水平。比较PTEN、p53、TERT启动子突变及MET和MMP．9高表达在各级别和各分子亚型胶质瘤中的分布差异。结果（1）在WHOⅡ、Ⅲ和Ⅳ级胶质瘤中，PTEN的突变率分别为2．8％（2／72）、5．0％（1／20）及23．0％（20／87），p53的突变率分另0为28．0％（21／75）、10．0％（2／20）及20．7％（18／87），TERT启动子的突变率分别为30．2％（26／86）、47．1％（8／17）及46．8％（29／62）；MET高表达率分别为28．9％（35／121）、33．3％（17／51）及37．5％（48／128）；MMP一9高表达率分别为3．3％（4／121）、39．2％（20／51）及59．4％（76／128）；各级别胶质瘤中PTEN的突变率和MMP-9高表达率的差异有统计学意义（均P〈0．01）。（2）前神经元型、神经元型、经典型和间质型胶质瘤分子亚型中，PTEN的突变率分别为1．9％（1／52）、12．5％（4／32）、15．0％（3／20）及20．0％（15／75），p53的突变率分别为34．0％（18／53）、6．1％（2／33）、40．0％（8／20）及17．1％（13／76），TERT启动子的突变率分别为37．5％（21／56）、34．5％（10／29）、31．3％（5／16）及45．1％（23／51）；MET高表达率分别为25．6％（21／82）、34．5％（19／55）、28．9％（11／38）及40．0％（38／95）；MMP-9高表达率分别为9．8％（8／82）、1．8％（1／55）、44．7％（17／38）及68．4％（65／95）；各分子亚型中PTEN、p53突变率及MMP-9高表达率差异有统计学意义（均P〈0．05）。结论PTEN的突变率和MMP-9高表达率与胶质瘤的恶性程度有关。PTEN、p53的突变率及MMP-9高表达率在胶质瘤各分子亚型中的差异，说明其能代表特定分子亚型胶质瘤的分子病理学特征。

Objective To investigate the distribution of the cell cycle alteration and cell migration as well as infiltrating growth process and related genetic changes in each grade and each molecular subtype of gliomas. Methods A total of 300 glioma specimens （ WHO grade Ⅱ-Ⅳ ） in Chinese Glioma Genome Atlas （CGGA） were collected. Its tissue RNA and DNA were extract respectively. Sanger sequencing was used to detect the mutation status of PTEN, p53, and TERT promoter. The expression levels of MET and matrix metalloproteinase 9 （MMP-9） were derived from whole-genome RNA microarray expression profile. The distribution differences of the mutations of PTEN, p53, TERT promoter and high expression of MET and MMP-9 were compared in each level and each molecular subtypes of glioma. Results （ 1 ） In WHO grade Ⅱ, Ⅲ and IV, the mutation frequencies of PTEN were 2.8% （2/72）, 5.0% （1/20）, and 23.0% （20/87）, respectively; the mutation rates of p53 were 28.0% （21/75）, 10.0% （2/20）, and 20.7% （ 18/87）, respectively; the mutation rates of TERT promoter were 30.2% （26/86）, 47.1% （8/17）, and 46.8% （29/62）, respectively; the incidences of MET high expression were 28.9% （35/121）, 33.3% （17/51）, and 37. 5% （48/128）, respectively; and the high expression rates of MMP-9 were 3. 3% （4/121）, 39.2% （20/51）, and 59.4% （76/128）, respectively. There were significant differences in each grade of gliomas between the mutation rate of PTEN and the high expression rate of MMP-9 （ all P 〈 0. 01 ）. （2） The mutation rates of PTEN in the proneural type, neural type, classical type and molecular type of mesenchymal glioma were 1. 9% （1/52）, 12. 5% （4/32）, 15. 0% （3/20）, and 20. 0% （ 15/75 ）, respectively ; the mutation rates of p53 were 34.0% （ 18/53 ）, 6.1% （ 2/33 ）, 40.0% （ 8/20）, and 17.1% （13/76）, respectively; the mutation rates of TERT promoter were 37.5% （21/56）, 34.5% （10/29）, 31. 3% （5/16）, and 45. 1% （23/51）, respectively; the MET high expression rates were 25.6% （21/82）, 34.5% （ 19/55 ）, 28.9% （ 11/38 ）, and 40.0% （ 38/95 ）, respectively ; the MMP-9 high expression rates were 9.8% （8/82）, 1.8% （1/55）, 44.7% （17/38）, and 68.4% （65/95）, respectively. There were significant differences in the mutation rates of PTEN and p53, and the MMP-9 high expression rates among each molecular subtype of glioma （ all P 〈 0.05 ）. Conclusions The mutation rate of PTEN and the high expression rates of MMP-9 were associated with the malignant degree of gliomas. The differences of the mutation rates of PTEN and p53, and the high expression rates of MMP-9 in each molecular subtype of gliomas suggested that they could represent the molecular pathologic features of the specific molecular subtypes of gliomas.