6A8 α-甘露糖苷酶表达减弱抑制鼻咽癌细胞CNE-2L2 转移的分子机制

目的 探讨6A8 α-甘露糖苷酶表达抑制对鼻咽癌细胞CNE-2L2间粘附性、细胞表达E-cadherin及对细胞接种裸鼠皮下所生长肿瘤肺转移的影响。方法 软琼脂培养观察非锚定状态下细胞间的粘附;间接免疫荧光染色、免疫组化染色及RT-PCR检测E-cadherin的表达;CNE-2L2细胞接种裸鼠皮下,8周后病理切片检测所长肿瘤肺转移程度。结果 6A8 α-甘露糖苷酶表达抑制的CNE-2L2细胞(AS)在非锚定状态下发生粘附,此粘附对Ca^2 有依赖性。野生型CNE-2L2细胞弱表达E-cadherin,但AS细胞的E-cadherin表达明显增强。E-cadherin表达增强既见于蛋白质水平,也见于mRNA水平。AS细胞接种裸鼠皮下所长肿瘤的肺转移明显受抑。结论 6A8 α-甘露糖苷酶表达抑制使CNE-2L2细胞间的粘附性增强,细胞表面E-cadherin表达增强,细胞接种裸鼠皮下所长肿瘤的肺转移明显受抑。

Molecular mechanism of metastasis inhibition of nasopharyngeal carcinoma cell CNE-2L2 induced by reduction of 6A8 alpha-mannosidase expression

OBJECTIVE: To study the effect of inhibition of 6A8 alpha-mannosidase expression on adhesiveness among and E-cadherin expression on CNE-2L2 cells, and on metastasis of the tumors from the cells inoculated in nude mice. METHODS: Anchorage-independent adhesion among cells was examined in soft agar culture. E-cadherin expression was studied by immunofluorescence staining, immunohistological staining and RT-PCR. CNE-2L2 cells were subcutaneously inoculated into nude mice. Eight weeks later tumor metastasis was demonstrated by means of histological examination of lung sections. RESULTS: CNE-2L2 cells with suppression of 6A8 alpha-mannosidase expression (AS) became aggregated. E-cadherin expression on wild type cells was very weak. In contrast, it was greatly enhanced on AS cells. The enhancement was detected on both protein and mRNA levels. Lung metastasis of the tumor from inoculated AS cells were heavily inhibited in nude mice. CONCLUSION: Inhibition of 6A8 alpha-mannosidase expression results in enhancement of cell-cell adhesion and of E-cadherin expression on CNE-2L2 cells. Lung metastasis of the tumor grown from AS cell inoculate in nude mice is heavily suppressed.