缺氧诱导因子1α过表达对人前列腺癌细胞体外侵袭能力的影响

目的观察转染缺氧诱导因子1α(HIF-1α)能否增强人前列腺癌细胞的体外侵袭能力,并探讨其分子机制。方法用脂质体Lipofectamine2000包装重组真核表达载体pCDNA3．1(-)／HIF1α后转染人前列腺癌细胞LNCaP,600μg／ml G418筛选稳定表达HIF-1α的抗性克隆。免疫荧光及Western印迹法鉴定HIF-1α过表达,Western印迹法检测侵袭相关蛋白E-钙黏素、波形纤维蛋白(vimentin)、基质金属蛋白酶-2(MMP-2)、组织蛋白酶D(cathepsin D)及尿激酶型纤溶酶原激活因子受体(uPAR)的表达,Transwell验证细胞侵袭能力。结果与未转染细胞LNCaP相比,转染细胞LNCaP／HIF1α中出现明显的HIF-1α蛋白条带,并激发出较强荧光,E-钙黏素表达缺失,而vimentin、MMP-2、cathepsin D及uPAR表达增加。Transwell试验进一步证实,LNCaP／HIF1α穿透Matrisel滤膜的细胞数比LNCaP细胞显著增多(4．6±0．4 vs 3．2±0．3,P<0．05)。结论HIF-1α过表达能够诱导人前列腺癌LNCaP细胞的侵袭相关蛋白表达增多,进而显著增强其体外侵袭能力。

Over-expression of Hypoxia-inducible factor 1alpha increases invasive potency of LNCaP cells in vitro

OBJECTIVE: To evaluate the effect of hypoxia-inducible factor-1alpha (HIF1alpha) over-expression on the invasive potency of human prostate cancer cell. METHODS: Human prostate cancer cells of the line LNCaP were cultured and transfected by the recombinant plasmid pcDNA3.1(-)-HIF-1alpha containing the gene HIF1alpha with Lipofectamine 2000 system. The positive clone cells were selected by G418 and confirmed by Western blotting and immunofluorescence staining (LNCaP/HIF1alpha cells). Transwell chambers with polycarbonate filter were coated by 100 microl Matrigel at 1:20 dilution in serum-free medium. LNCaP cell suspension and LNCaP/HIF1alpha cell suspension were inoculated into the Transwell chambers respectively for 24 hours to analyze the invasive potency. Western blotting was used to detect the expression of E-cadherin, vimentin, matrix metalloproteinase-2 (MMP-2), cathepsin D, and urokinase-type plasminogen activator receptor (uPAR). RESULTS: The expression level of HIF1alpha in the LNCaP/HIF1alpha cells was distinctly higher than that in the LNCaP cells. The numbers of LNCaP-HIF1alpha cells penetrating through the Transwell polycarbonate filter was 4.6 +/- 0.4 x 10(4), significantly higher than that of the LNCaP cells (3.2 +/- 0.3 x 10(4), P < 0.01). The expressions of vimentin, MMP-2, cathepsin D, and uPAR were all up-regulated in LNCaP-HIF1alpha cells than those of the LNCaP cells. Whereas, the expression of E-cadherin was down-regulated in the LNCaP-HIF1alpha cells. CONCLUSION: Over-expression of HIF-1alpha stimulates the invasion potency of human prostate carcinoma cell. The expression of E-cadherin, vimentin, MMP-2, cathepsin D, and uPAR, all playing an established role in the invasion of tumor, can be regulated by HIF-1 in human prostate cancer cell.