Tomatidine是由Fusarium oxysporum f. sp.所感染的番茄經由tomatianse修飾α-tomatine後的天然固醇類生物鹼。近年來有研究發現tomatidine可以抑制inducible NOS (iNOS)和cyclooxygenase-2 (COX-2)而降低發炎的作用。可是，tomatidine對癌細胞轉移方面的研究尚不清楚，因此本論文目的在研究tomatidine對人類肺癌細胞A549爬行及侵入作用的影響。我們發現50 μM的tomatidine處理細胞24與48小時後可抑制細胞生長。以無細胞毒性的tomatidine劑量進行體外傷口癒合試驗及Boyden chamber侵入試驗，發現tomatidine對於細胞爬行的抑制作用並不顯著，但是對於細胞的侵入作用有明顯的抑制。利用gelatin zymography觀察tomatidine是否會降低基質金屬蛋白酶(MMP-2/9)的活性；並以Reverse transcription-PCR (RT-PCR)觀察MMP-2/-9 mRNA的表現量；接著以西方墨點法來看tomatidine對Mitogen-activated protein kinase (MAPK)及phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway的影響。結果發現tomatidine對於MMP-2/-9的活性與其mRNA的表現量抑制效果並不顯著。同時利用西方墨點法，發現tomatidine能夠抑制訊號傳遞蛋白的表現量包括AKT、ERK、JNK及轉錄因子NF-κB。經由上述研究結果證實，tomatidine藉由抑制A549細胞的訊號傳遞蛋白AKT、ERK、JNK及NF-κB的表現量 ，進而影響A549細胞的侵入。 Tomatidine, isolated from tomato, is a naturally occurring steroidal glycoalkaloid. Recent study demonstrated that tomatidine suppressed inflammation by reducing iNOS and COX expression. However, the effect of tomatidine on metastasis of caner cell is still unclear. In the present study, we aimed to elucidate the potential of tomatidine on suppressing migration and invasion of human lung cancer cell A549. We found that treatment of 50 μM of tomatidine for 24 and 48 h could inhibit A549 cell proliferation. The nontoxic doses of tomatidine were utilized to examine its anti-migratory and anti-invasive activities by in vitro wound healing assay and Boyden chamber invasion assay, respectively. We demonstrated that the cells migration was not altered significantly, whereas cell invasion was suppressed markedly. The inhibitory mechanisms of tomatidine associated with anti-invasion were investigated further. Tomatidine reduced the activity and expression of matrix metalloproteinase-2 and MMP-9 (MMP-2 and MMP-9) which are involved in cell invasion. Meanwhile, tomatidine can significantly suppressed the upstream signaling of MMP-2 and MMP-9 including PI3K, Akt and MAPK pathways. Taken together, these results suggested that tomatidine inhibited A549 invasion by reducing MMP-2 and MMP-9 activity and these findings reveal a new therapeutic potential for tomatidine on anti-metastatic therapy.
