抑癌基因p27及致癌基因c-myc之mRNA於鼻咽癌組織中的表現

mRNA Expression of Tumor Suppressor Gene p27 and c-myc Oncogene in Nasopharyngeal Carcinoma

李家宏(Chia-Hug Li) ； 蘇志英(Chih-Ying Su) ； 簡志彥(Chih-Yen Chien) ； 黃昭誠(Chao-Cheng Huang) ； 黃純真(Shung-Chen Huang) ； 蕭雅瓊(Yea-Chyang Hsiao) ； 黃仲鋒(Chung-Feng Hwang)

《台灣耳鼻喉頭頸外科雜誌》 38卷6期 (2003/12) Pp. 239-246

https://doi.org/10.6286/2003.38.6.239

摘要

背景：p27是cyclin-dependent kinases抑制劑，屬於抑癌基因的一種，在之前報告顯示p27蛋白表現降低與多種人類癌症的惡化有關。而c-myc屬於致癌基因，它調控的核蛋白，可以控制細胞增生、分化、腫瘤變性(transformation)及細胞凋亡(apoptosis)等，其表現與鼻咽癌臨床表現有關。本研究檢查p27及c-myc mRNA及蛋白在鼻咽癌組織中的表現並探討其臨床病理表徵、預後因子及相互間的關聯性。
方法：以reverse-transcriptase polymerase chain reaction (RT-PCR)及免疫組織化學法染色偵測21例鼻咽癌檢體中p27及c-myc 其mRNA及蛋白的表現，mRNA表現分為有及低度表現兩類，蛋白質依其染色強度分為無、中等及強烈3等級。
結果：21例鼻咽癌檢體中，13例(62%) p27 mRNA有表現，8例(38%) p27 mRNA低度表現。c-myc mRNA在18例(86%)有表現，c-myc mRNA有3例(14%)低度表現。在蛋白質表現方面，p27與c-myc蛋白表現依無、中等及強烈順序分別是5，5，11例及2，11，8例。統計分析顯示p27蛋白與mRNA並無明顯相關性，c-myc蛋白與mRNA則呈現明顯相關性，但兩者的mRNA與臨床病理表徵及預後因子皆無明顯相關性存在。
結論：在鼻咽癌組織中，p27表現有降低的傾向，此外c-myc在大多數病例中也有表現，足見其在鼻咽癌癌化過程中應扮演重要角色。c-myc mRNA與其蛋白的表現有相關性存在，p27則無此關聯性，推測c-myc mRNA可能是調控蛋白表現的主要因素之一。而c-myc mRNA和p27 mRNA兩者在鼻咽癌組織中的表現並無法預測疾病進展度及預後狀況。

關鍵字

鼻咽癌 ； p27 ； c-myc ； mRNA

並列摘要

BACKGROUND: Tumor suppressor gene p27 is one of the cyclin-dependent kinase inhibitors and low levels of p27 protein have been reported to correlate with aggressive behaviors in various human carcinomas. The c-myc oncogene encodes a nuclear regulatory protein that has been shown to be involved in the regulation of cell proliferation, differentiation, neoplastic trans formation and apoptosis. Previous studies have shown that its express ion correlates clinically with nasopharyngeal carcinoma (NPC). This study investigated the correlation between mRNA and protein express ion of p27 and c-myc, and then investigated the association between mRNA expression and clinical outcomes.
METHODS: Reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemical staining (IHC) of p27 and c-myc was performed for 21 patients with NPC. The mRNA level was assessed as low or positive by comparison with a control study. The IHC staining was assessed as nil, intermediate or intense.
RESULTS: The RT-PCR results indicated that 13 had p27 mRNA expression, eight had low p27 mRNA express ion, 18 had c-myc mRNA express ion and only three had low c-myc mRNA expression. The IHC staining results demonstrated that 11 had intense staining for the p27 protein, five had intermediate staining and five showed weak staining. For the c-myc oncogene, eight had intense staining, 11 intermediate staining and only two had no staining. Direct correlation between c-myc protein and mRNA was found, but this relationship was not noted for p27 expression. There was no significant association noted between each mRNA and clinciopathological factors or prognosis.
CONCLUSIONS: The trend of reduced p27 expression and increased incidence of c-myc protein and mRNA express ion was found in NPC tissue, making the involvement of p27 and c-myc in the process of neoplastic progress ion of NPC likely. Expression of c-myc protein correlated with mRNA expression, but this was not the case for p27. The study failed to identify a correlation between c-myc mRNA or p27 mRNA and NPC disease behavior and prognosis.

並列關鍵字

nasopharyngeal carcinoma ； p27 ； c-myc ； mRNA