癌症轉移是癌症中最急迫的議題。整合素在惡性腫瘤轉移扮演了極重要的角色。最近研究指出整合素和ADAM交互作用控制癌症轉移， 其中也包括ADAM9與整合素。為了進一步分析ADAM9在前列腺癌轉移中扮演的角色，我們使用
micro-slide Chemotaxis chambers 去比較knockdown of ADAM9 和parental PC3
，Time-Lapse microscope 分析的比較顯示在parental prostate cancer cells移動距離與移動能力比ADAM9 knockdown cells強，流式細胞儀分析顯示knockdown PC3 cells 不影響細胞表面大部分整合素的表現但會影響整合素α2β1。免疫共沉澱中顯示ADAM9 是與整合素 β4有交互作用而不是與β1因此我們現在的目標為探討ADAM9在整合素所控制的癌症轉移與遷移中的機制。我們的假設為ADAM9可能調控攝護腺癌中RAC1 和RAC1的下游表現,接著我們去探討ADAM9是否調控了整合素β4的訊息傳遞，首先我們使用攝護腺癌細胞PC3，接著在PC3轉殖ADAM9 siRNA， Rac1的活性使用pull-down assays去探測而 Rac1的下游則使用西方墨點法去觀察，Silencing of ADAM9會增加RAC1 和 downstream的表現和細胞的貼附能力但是在control cell並沒有看到這種現象，我們的假設為ADAM9 是當細胞在不同的細胞基質中去選擇性調控不同的整合素進而去控制細胞移動，當癌症細胞同時表現整合素β1和 β4而他們各至與不同的胞外基質有交互作用，ADAM9動態調節β1和β4所影響的細胞移動，而我們的結論為ADAM9在控制細胞長距離移動和轉移中扮演了極重要的角色，Knockdown of ADAM9在細胞遷移實驗中會大幅度降低轉移能力，因此了解ADAM9與整合素的交互作用是有機會成為治療癌症轉移的重大發現
Metastasis is the most lethal condition in cancer patient. Integrin composition is highly correlated with cancer malignancy and metastasis. Recent studies indicated cancer metastasis involved the interaction between integrin and ADAM (A disintegrin and a metalloproteinase) gene family, including the interaction of ADAM9. To further analyze the role of ADAM9 in prostate cancer metastasis, migration assay was performed using micro-slide Chemotaxis chambers to compare the migratory activities between ADAM9 knockdown and parental PC3 prostate cancer cells. Time-lapse microscope analysis revealed the different cell migration behavior in which faster and longer cell migration distance was observed in parental prostate cancer cells. By contrast, shorter and local scattering activities dominanted in ADAM9 knockdown cells. Flow cytometry analyses showed not altered integrin expression in ADAM9 knockdown of PC3 cells. Co-immunoprecipitation of ADAM9 indicated it’s interaction with integrin β4 but not β1. Therefore, the major focus of our studies is the role of regulatory mechanisms of ADAM9 in integrin and downstream signaling for cancer migration and invasion. We hypothesized that ADAM9 may mediate RAC1 activation and downstream in prostate cancer cell. To investigate whether ADAM9 regulate integrin β4 and downstream signaling. Rac1 activation was determined by pull-down assays and Rac1 downstream was defined by immunoblots. Silencing of ADAM9 increased RAC1 and downstream activation and adhesion, control group did not observe this phenonemen. Our hypothesis is ADAM9 can selectively affect cell migration by different integrins. ADAM9 can affect integrin-mediated migration when cancer cell interact to different matrix. If integrins β1 and β4 both express in cancer cell, they will bind to different matrix. The expression of ADAM9 could dynamically regulate β1 and β4 for migration in different matrix. In summary, ADAM9 is important in regulating long distance migration and metastasis of prostate cancer cells. Therefore, inhibition of ADAM9 and integrin interaction could be useful as therapeutic strategy of metastasis in prostate cancer patients.
