| 摘要: | 檳榔生物鹼，特別是檳榔鹼，具有許多生物活性。雖然實驗室之前的研究中發現檳榔鹼會使得前列腺正常細胞RWPE-1生長停滯在G2/M phase；前列腺癌細胞PC-3與LNCaP會分別停滯在G2/M phase與G0/G1 phase，但是其作用機制目前仍不清楚。我們利用這三株細胞的控制細胞週期蛋白來觀察檳榔鹼如何差異控制前列腺正常細胞與癌細胞的細胞週期停滯。在RWPE-1細胞，檳榔鹼會誘發CDK1、p21、cyclin B1與cyclin D3的蛋白增加但不影響CDK2、CDK4、p27與cyclin D1的蛋白質表現。在PC-3細胞，檳榔鹼有降低CDK1、p21、p27、cyclin D1、cyclin D3蛋白與增加cyclin B1蛋白表現的趨勢，但不影響CDK4與CDK6蛋白。在LNCaP-FGC細胞，檳榔鹼會誘導CDK2、CDK4與cyclin D1的減少與增加p21、p27和cyclin D3的蛋白質表現，對於CDK1與cyclin B1則是沒有影響。這些結果顯示，檳榔鹼是依靠CDK家族蛋白、CKI家族蛋白與cyclin 家族蛋白來調前列腺正常細胞與癌細胞的細胞週期。有趣的是，在RWPE-1細胞，預處理N-acetylcysteine (NAC)阻擋檳榔鹼增加CDK1、cyclin B1與D3但不阻擋p21的增加；而在PC-3細胞，NAC能夠防止檳榔鹼誘導的CDK2的降低，但不能預防CDK1的降低，同時能夠防止cyclin B1的增加。在LNCaP細胞，檳榔鹼降低的CDK2、CDK4和cyclin D1的蛋白質表現，並抑制檳榔鹼所誘導蛋白質p21、p27和cyclin D3的上升。這些資料顯示了，檳榔鹼的氧化能力對於前列腺正常細胞與癌細胞在調控細胞週期方面會有不同的影響，也因此讓前列腺正常細胞與癌細胞停滯在各自的週期;Betel nut alkaloids (BNAs), especially arecoline, possesses multiple biological activities. Although arecoline was found from our laboratory to induce the G2/M growth arrest of normal human RWPE-1 prostate cells and the respective G2/M and G0/G1 growth arrests of human PC-3 and LNCaP prostate cancer cells, the exact mechanisms of its differential actions are still not clear. Using all the three cell lines, we investigated cell cycle controlling proteins involved in differential arecoline modulations of normal and cancerous prostate cell growth arrests. In RWPE-1 cells, arecoline induced increases in CDK1, p21, and cyclins B1 and D3 proteins and no significant effects in CDK2, CDK4, and cyclin D1 protein levels. In PC-3 cells, arecoline tended to decrease levels of CDK1, p21, p27, cyclin D1, and cyclin D3 proteins and increase cyclin B1 levels, but it had no effects on CDK4 and CDK6 proteins. In LNCaP cells, arecoline induced decreases in CDK2, CDK4, and cyclin D1 proteins, increases in p21, p27, and cyclin D3 proteins, and no effects on CDK1 and cyclin B1 proteins. These data suggest that arecoline regulates the cell cycles of normal and cancerous prostate cells in CDK subfamily-, cyclin subfamily-, and CKI subfamily-dependent manners. Interestingly, pretreatment with the antioxidant N-acetylcysteine (NAC) blocked the arecoline induced increases in CDK1 and cyclins B1 and D3 but not p21 proteins in RWPE-1 cells, while NAC prevented arecoline-induced decreases in CDK2 but not CDK1 proteins and arecoline-increased cyclin B1 protein levels in PC-3 cell. In LNCaP cells, NAC blocked arecoline-decreased levels of CDK2, CDK4 and cyclin D1 proteins and suppressed arecoline-increased levels of p21, p27, and cyclin D3 proteins. These data suggest that the oxidant activity of arecoline made different impacts on cell cycle controlling proteins between normal and cancerous prostate cancer cells and thereby inducing different phases of their growth arrests. |
