摘要：

目的：观察恶性多形性腺瘤（malignant in pleomorphic adeoma，MPA）组织中谷胱甘肽过氧化物酶3（glutathione peroxidase 3，GPX3）蛋白、基因甲基化水平及临床意义。方法： 选取2021年1月—2023年1月在新疆医科大学第二附属医院接受手术治疗的55例唾液腺多形性腺瘤（salivary gland pleomorphic adenoma，SPA）、24例MPA患者肿瘤组织及55例上述患者的正常腺组织。免疫组织化学法检测组织中GPX3蛋白的表达，甲基化特异性聚合酶链反应（methylation specific polymerase chain reaction，MSP）法检测组织中GPX3甲基化程度，分析其与临床病理特征的关系。选择人恶性多形性腺瘤细胞系SM-AP1，转染GPX3过表达载体、空载体，并将其分为过表达空载体组（Vector组）、GXP3表达组（OE-GPX3组），实时定量聚合酶链反应（real-time quantitative polymerase chain reaction，RT-qPCR)和蛋白质印迹法（Western blotting）检测GPX3 mRNA及蛋白表达量；CCK8法检测细胞增殖能力；transwell小室检测细胞侵袭能力。结果： GPX3蛋白在正常腺体组织中的阳性表达率（90.9%，50/55）高于其在SPA（56.4%,31/55）和MPA（29.2%，7/24）组织中；GPX3蛋白在SPA组织中的阳性表达率高于其在MPA组织中，且差异具有统计学意义（P<0.001）。正常腺体组织中，GPX3的甲基化比例（7.3%，4/55）低于SPA组织（34.5%，19/55）和MPA组织（66.7%，16/24）中，SPA组织中的GPX3甲基化比例低于MPA组织中，差异具有统计学意义（P<0.001）。GPX3甲基化水平与MPA患者TNM分期、分化程度、恶性成分比例有关（P<0.05）。GPX3蛋白阳性表达率与TNM分期、恶性成分比例有关（P<0.05）。与Vector组比较，OE-GPX3组细胞GPX3 mRNA、蛋白表达量显著上升，48 h及72 h的吸光度值、侵袭细胞数量降低，差异具有统计学意义（P<0.01）。结论： 恶性多形性腺瘤GPX3基因启动子甲基化程度高，与TNM分期、分化程度、恶性成分比例呈负相关，有潜力成为诊断恶性多形性腺瘤的预警分子指标和临床治疗中的基因调控靶点。

关键词: 恶性多形性腺瘤, 谷胱甘肽过氧化物酶3, 甲基化, 临床病理特征

Abstract:

Objective: To observe the methylation and protein levels of glutathione peroxidase 3 (GPX3) in malignant pleomorphic adenoma (MPA) tissue and its clinical significance.Methods: A total of 55 cases of salivary gland pleomorphic adenoma (SPA), 24 cases of MPA, and 55 cases of normal glandular tissue from patients who underwent surgical treatment at the Second Affiliated Hospital of Xinjiang Medical University from January 2021 to January 2023 were selected. Immunohistochemical method was used to detect the expression of GPX3 protein in tissues. Methylation specific polymerase chain reaction (MSP) method was used to detect the degree of GPX3 methylation in tissues. The relationship between clinical pathological features and methylation was analyzed. Human malignant pleomorphic adenoma cell line SM-AP1 was selected and transfected with GPX3 overexpression vector and empty vector, and they were divided into Vector group and OE-GPX3 group. Real-time quantitative polymerase chain reaction(RT-qPCR) and western blotting were used to detect GPX3 mRNA and protein expression. CCK8 was used to detect cell proliferation ability. Transwell chamber was used to detect cell invasion ability. Results: The positive rate of GPX3 protein in normal glandular tissues (90.9%, 50/55) was higher than that in SPA (56.4%, 31/55) and MPA (29.2%, 7/24) (P<0.001). The proportion of GPX3 protein methylation in normal glandular tissues (7.3%, 4/55) was lower than that in SPA tissues (34.5%, 19/55) and MPA tissues (66.7%, 16/24) (P<0.001). The methylation level of GPX3 was related to TNM stage, differentiation degree, and proportion of malignant components in MPA patients (P<0.05). The positive rate of GPX3 protein was related to TNM stage and the proportion of malignant components (P<0.05). Compared with the Vector group, the OE-GPX3 group showed a statistically significant increase in the mRNA and protein expression levels of GXP3, optical density values at 48 and 72 hours, and the number of invasive cells were decreased, and the difference was statistically significant (P<0.01). Conclusion: The GPX3 gene in MPA has a high degree of methylation initiation, which is negatively related to TNM stage, differentiation, and proportion of malignant components. It has the potential to become a warning molecular indicator for diagnosing malignant pleomorphic adenoma and a gene regulatory target in clinical treatment.

Key words: malignant pleomorphic adenoma, glutathione peroxidase 3, methylation, clinical pathological features

中图分类号: 

• R782

• R739.8