自噬相关基因BECN1、LC3B和mTOR在宫颈病变中的表达及其临床意义

发布时间：2018-08-17 09:44

【摘要】：每年,在中国宫颈癌的新发病例高达10万之多,并且呈现年轻化趋势。目前,手术及放疗是治疗宫颈鳞状细胞癌的有效方法,但其造成的生理功能损害及器官缺失无法逆转,因此寻求一种破坏性小,副作用小的疗法极为迫切。靶向治疗,是在细胞分子水平上,针对已经明确的致癌位点特异性杀伤目的细胞而不波及到正常组织。因此,追求精准和高效是未来治疗宫颈癌的方向。自噬,存在于正常细胞中的一种生理功能,已发现其过度激活可以造成类似于凋亡的程序性死亡。因此,自噬相关基因可能成为治疗恶性肿瘤的潜在靶点,即通过调节肿瘤细胞中的自噬水平,诱导目的细胞死亡,可谓癌症治疗新的曙光。在自噬相关基因中,BECN1作为自噬程序的启动子,正向调节自噬功能;mTOR作为逆向调控的枢纽,抑制细胞自噬行为;LC3B是自噬体膜性结构的标记者,其表达水平反映自噬活性的强弱。根据2014年第4版WHO女性生殖系统肿瘤分类。本实验以LSIL、HSIL、宫颈鳞状细胞癌为研究对象;以正常宫颈组织为对照。运用免疫组织化学Super Vision法及FISH技术,纵向检测自噬相关基因在宫颈病变中的mRNA及蛋白表达程度;正、反横向探究BECN1、LC3B和mTOR在逐级宫颈病变中的表达差异。以期全方位评估自噬活性与宫颈病变之间的相关性。研究发现,BECN1在LSIL、HSIL及宫颈鳞状细胞癌中的蛋白表达分别是21.46±19.48、12.93±11.67、6.28±5.89,而正常宫颈组织中为36.66±23.28。提示:随着宫颈病变的进展,BECN1的表达呈现下调趋势,且均低于正常宫颈组织的表达水平。其各组间差异具有统计学意义(P0.05)。mRNA的表达也呈现相同趋势。LC3B在LSIL、HSIL及宫颈鳞状细胞癌中的蛋白表达分别是22.63±15.09、12.61±8.96、6.99±5.71,在正常宫颈中的表达为34.84±15.91。提示:LC3B在宫颈病变中的表达均低于正常宫颈,并且随着宫颈病变的进展,表达水平越低,各组间差异具有统计学意义(P0.05)。LC3B的mRNA表达也呈现类似趋势。mTOR在HSIL及癌组中的蛋白表达分别是24.02±17.48、35.48±19.65,显著高于正常宫颈组(6.9±6.69),而LSIL中的蛋白表达(12.02±9.48)与正常宫颈相比差异无统计学意义(P0.05)。提示:随着宫颈病变的进展,mTOR的蛋白表达水平越高,其mRNA的表达趋势与之相似。经统计学分析,BECN1的表达与淋巴结转移及肿瘤临床分期有关,即在有淋巴结转移的患者中呈低表达,且随着临床分期越高,表达越少;LC3B与肿瘤分化程度相关,在中低分化的患者中呈低表达;而mTOR与有无淋巴结转移相关,且在有淋巴结转移的患者中呈现明显高表达。另外在宫颈鳞状细胞癌组中,LC3B与BECN1的表达呈正相关(r=0.642,P0.01),与mTOR的表达呈负相关(r=-0.418,P0.01);但BECN1与mTOR的表达无明显相关性。综上所述,根据BECN1、LC3B和mTOR在宫颈病变及正常宫颈中的表达情况,反映自噬活性随着病变的进展而下调,并且在HSIL及宫颈癌组中呈明显的自噬缺陷。这可能提示,低水平的自噬活性可能是影响宫颈病变进展的因素之一。同时,BECN1、LC3B和mTOR的mRNA与蛋白表达结果趋势一致,表明可能在遗传物质转录、翻译阶段,已有自噬关键基因的相互作用以及干扰。另外,自噬相关基因的表达与患者有无淋巴转移,肿瘤细胞分化程度及临床分期有关,推测自噬活性可能影响宫颈癌患者的预后。
[Abstract]:Nowadays, surgery and radiotherapy are effective methods for the treatment of cervical squamous cell carcinoma, but the damage of physiological function and organ loss can not be reversed. Therefore, it is very urgent to seek a treatment with less destructive and side effects. Autophagy, a physiological function of normal cells, has been found to cause apoptosis-like programmed death by over-activation. Thus, autophagy-related genes may become potential targets for the treatment of malignant tumors, that is, by regulating the level of autophagy in tumor cells and inducing the death of target cells, which is a new dawn for cancer treatment. LC3B is a marker of autophagy membrane structure, and its expression level reflects the intensity of autophagy activity. According to the WHO classification of female reproductive system tumors in the 4th edition of 2014, LSIL, HSIL, cervical squamous cell carcinoma were studied in this experiment, and normal cervical tissues were taken as control. Longitudinal detection of autophagy-related genes in cervical lesions mRNA and protein expression; positive and negative cross-sectional study of BECN1, LC3B and mTOR in progressive cervical lesions in order to fully assess the correlation between autophagy and cervical lesions. The expression of BECN 1 was down-regulated with the progression of cervical lesions, and was lower than that of normal cervical tissues. The difference was statistically significant (P 0.05). The expression of mRNA also showed the same trend. LC3B was found in LSIL, HSIL and uterus. The expression of LC3B protein in cervical squamous cell carcinoma was 22.63 (+ 15.09), 12.61 (+ 8.96), 6.99 (+ 5.71) and 34.84 (+ 15.91) respectively in normal cervix. The expression of mTOR protein in HSIL and cancer group was 24.02 [17.48] and 35.48 [19.65] respectively, which was significantly higher than that in normal cervix group (6.9 [6.69]). However, the expression of mTOR protein in LSIL was not significantly different from that in normal cervix (P 0.05). Statistical analysis showed that the expression of BECN1 was related to lymph node metastasis and clinical stage, that is, the expression of BECN1 was low in patients with lymph node metastasis, and the higher the clinical stage, the less the expression of BECN1; LC3B was related to the degree of tumor differentiation, but the expression of mTOR was low in patients with moderate and low differentiation, and the expression of mTOR was related to lymph node metastasis. In addition, the expression of LC3B was positively correlated with BECN1 (r = 0.642, P 0.01) and negatively correlated with the expression of mTOR (r = - 0.418, P 0.01), but there was no significant correlation between BECN1 and mTOR. The expression of BECN1, LC3B and mTOR in normal cervix reflects that autophagy activity is down-regulated with the progression of cervical lesions and shows obvious autophagy deficiency in HSIL and cervical cancer. This may suggest that low level of autophagy activity may be one of the factors affecting the progression of cervical lesions. In addition, the expression of autophagy-related genes is related to lymphatic metastasis, tumor cell differentiation and clinical stage. It is speculated that autophagy activity may affect the prognosis of cervical cancer patients.
【学位授予单位】：河北北方学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R737.33

【参考文献】