| 摘要: | a-Solanine為天然固醇類生物鹼，存在於發芽之馬鈴薯、番茄及許多茄科植物中。a-Solanine被發現具有抗癌之作用，如抑制腫瘤細胞增生及誘導細胞凋亡等。先前我們證明a-solanine藉由抑制基質金屬蛋白酶-2及-9 (MMP-2及-9) 之表達，進而抑制人類黑色素瘤細胞遷移和侵襲之能力。於本論文中，我們研究a-solanine抑制前列腺癌PC-3細胞體外轉移之機制。本研究利用不同濃度之a-solanine處理PC-3細胞後以MTT分析其對細胞存活之影響，接著選用不影響細胞生長之a-solanine劑量處理細胞，進行體外wound healing assay 和 Boyden chamber assay，以檢測a-solanine對細胞爬行和入侵能力之影響。此外利用即時定量聚合酶鏈鎖反應檢測PC-3細胞中miR-21、miR-138等microRNA和MMP-2/-9、組織金屬蛋白酶抑制蛋白TIMP-1/-2、細胞外基質金屬蛋白酶誘導因子 EMMPRIN和RECK等mRNA之表現。實驗數據顯示，隨著 a-solanine 濃度增加可有效抑制PC-3細胞之存活。當以12 uM之a-solanine處理後，細胞入侵能力有顯著性之抑制。另外，12uM的a-solanine可抑制MMP-2、MMP-9與EMMPRIN的mRNA表現，同時誘導了TIMP-2表現。另外，以a-solanine處理細胞後發現miR-21和miR-138都有受到調控。a-Solanine可誘導miR-138和抑制miR-21的表現。a-Solanine 亦可抑制vimentin，並同時誘導E-cadherin表現，顯示a-solanine可能可以藉由調控PC-3細胞進行上皮細胞轉型成間葉細胞(EMT)的過程來影響細胞的侵入作用。本研究發現a-Solanine可能經由影響miR-21與miR-138的表現，以及調控MMP-2/-9、EMMPRIN、TIMP-2表現，並抑制EMT而降低前列腺癌細胞PC-3的侵入作用。此結果為a-solanine的抗癌細胞轉移作用提供進一步的作用機轉。
a-Solanine is a glycoalkaloid found in Solanaceae.a-Solanine possesses anti-carcinogenic properties, such as inhibiting proliferation and inducing apoptosis of tumor cells. Recently, we demonstrated that a-solanine suppressed migration and invasion of human melanoma cells. In the present study, we examined the inhibitory effect of a-solanine on metastasis of prostate cancer cell PC-3 in vitro. The effect of a-solanine on viability of prostate cancer cell PC-3 was determined by MTT assay. Then the effect of non-toxic doses of a-solanine on cell migration and invasion was examined by in vitro wound healing assay and Boyden chamber assay, respectively. Based on the previous studies, miR-21 suppressed MMP inhibitor RECK expression through the transcriptional repression. In addition, miR-138 may down regulate vimentin expression thereby affecting cell attachment and migration. There fore, the mRNA and micro RNA expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR), including metalloproteinase-2 (MMP-2), MMP-9, tissue inhibitor of metalloproteinase-1/-2 (TIMP-1/-2), extracellular inducer of matrix metalloproteinase (EMMPRIN), micro RNA-21 (miR-21) and miR-138. Data indicated the a-solanine can inhibit the viability of human prostate cancer PC-3 cell in a dose-dependent manner. When treated with non-toxic doses of a-solanine, cell invasion was inhibited significantly. a-Solanine inhibits expression of MMP-2, MMP-9 and EMMPRIN, while induces expression of tissue inhibitor of metalloproteinase-1/-2 (TIMP-1/-2). a-Solanine also inhibits miR-21 and induces miR-138 expression in PC-3 cells. In addition, a-solanine reduces vimentin and elevates E-cadherin expression, suggesting a-solanine may inhibit epithelial-mesenchymal transition of PC-3 cells. Taken together, the results suggest that a-solanine inhibits invasion of PC-3 cells may be through suppressing expression of MMP-2, MMP-9, EMMPRIN and inducing expression of TIMP-2 and E-cadherin. These findings reveal new therapeutic potential for a-solanine in anti-metastatic therapy. |
