在先前的實驗裡，我們發現因為ras基因過度的表達使T24膀胱癌細胞株產生對Genistein的抵抗力，一旦使用Antisense oligonucleotide抑制 ras的表達，該細胞株的生長如同其他膀胱癌細胞株 TCCSUP、TSGH8301一樣，就會被Genistein強烈的抑制。在這研究裡，我們欲探討Genistein是經由那一個與 ras有關的訊息傳遞途徑，達到抑制 T24細胞生長的結果。經過使用許多磷酸脢抑制劑，如PD98059、U0126(以上對抗 MEK/ERK)、LY294002(對抗 PI3K)、H7(對抗 PKC)及Anti-fos Antisense oligonucleotide處理T24細胞後，再定量它們的生長能力，我們發現只有ras→raf→MEK/ERK→c-fos的途徑可以傳遞Genistein抑制T24細胞生長的訊息。由於Genistein正在臨床上測試其抑制各種癌症的能力，而許多癌症包括膀胱癌的起因與被ras基因的變異與表達有關，所以本實驗結果可以做為預先評估Genistein治療膀胱癌之參考；假如病患膀胱癌證實有 ras基因的變異，則Genistein的療效是很差的。
In the previous experiments, we have shown that the antisense oligonucleotide blocking the expression of the mutated ras gene in T24 bladder transitional carcinoma cells lead to the susceptibility of growth inhibition by genistein. In this research, we aimed to define the Ras-associated signal transduction pathway that mediated this inhibitory effect. By assaying the growth rates of T24 cells treated with a variety of protein kinase inhibitors, including PD98059 and U0126 that were for against of MEK/ERK; LY294002 that was for against PI3K; and H7 that was for against PKC, and anti-fos antisense oligonucleotide, we found that the inhibitory effect of genistein was mediated through the pathway of ras→raf→MEK/ERK→c-fos and no other pathway was involved. Since genistein is currently being evaluated as an anticancer drug in many clinical trials and the ras mutation with over expression has been associated with many cancers including bladder cancer, the result of this study provides a possible prognostic factor of the efficacy of the drug to treat patients with bladder transitional carcinomas with or without the ras expression abnormality.
