重金屬砷是一個已知的致癌因子。在烏腳病流行地區, 當人類由於職業上,醫藥上,或長期飲水上接觸砷會造成皮膚, 膀胱, 或是肺臟的癌化。但是, 關於長期飲水中含砷造成膀胱癌確切的作用機轉及方式目前並不是十分清楚。很多流行病學的證實, 在烏腳病流行地區, 飲水中砷的含量和膀胱癌成正比。為了探討砷所引起之膀胱癌的分子機制和相關之腫瘤因子, 我們先以E7細胞株處理0.05 ppm的砷處理3星期, 再以液相層析串聯質譜儀方法來看蛋白變化的情形.我們總共找出507蛋白, 其中有85個蛋白是被正向調控, 而有47個是被負向調控. 這些蛋白經過生物資訊的分析後,發現他們分別和糖類與脂質代謝, 細胞的移動, 蛋白折疊, 蛋白合成, 轉錄作用, 細胞骨架, DNA修補, 細胞週期控制, 以及訊息傳導相關. 其中有7個 蛋白被挑出來用西方點墨法進一步去確認帶白質體方法的正確性。最後, 我們挑出NPM來作進一步的研究。用反轉錄聚合酶反應以及西方點墨法, 我們發現NPM確實會受到砷的正面調控而且會隨砷的劑量增加而增加.更進一步, 砷的處理會使得細胞週期進行加速且可能會保護細胞免於死亡. 然而, 發現NPM大量表達也會促進細胞週期進行。而且, 當NPM大量表達,會降低一些和血管新生相關的因子的表達,但卻會增加u-PA (和癌症轉移相關的因子) 的表達. 在這個研究當中, 我們發現NPM 在砷相關的膀胱癌化過程中扮演著重要的角色.未來將挑出穩定表達的轉植細胞株以利進一步的深入研究.

Arsenic is a human carcinogen and has been linked to prevalence of cancers of skin, bladder, or lung in populations highly exposed to arsenic occupationally, medicinally, or through contaminated drinking water in the Blackfoot disease (BFD) endemic area. Nevertheless, the mechanism underlying neoplastic transformation induced by Arsenite (As2O3) remains unclear. A number of epidemiological studies have demonstrated a positive association of arsenic levels in drinking water with development of bladder cancer in BFD endemic area. To explore the molecular mechanisms of arsenic-related bladder carcinogenesis and their associated biomarkers, we performed the LC/MS/MS screening on immortalized E7 cells after challenging with arsenic in vitro. With this approach, a total of 85 up-regulated genes and 47 down-regulated proteins were identified from among 502 proteins by proteomic profiling. Bioinformatics analysis of gene ontology revealed that these proteins are related to carbohydrate and lipid metabolism, cell motility, protein folding, protein biosynthesis, transcription, cytoskeleton, DNA repair, cell cycle control, and signal transduction. Several proteins were analyzed by western blot to verify the accuracy of our approach. Among them, NPM (nucleophosmin) was chosen for further investigation of the novel molecular mechanisms of arsenic-related bladder carcinogenesis. Up-regulation of NPM by arsenic treatment in vitro was confirmed by western blot and RT-PCR, and tends to exhibit a dose-response pattern. We found that As treatment accelerates the progression of cell cycle, and up-regulation of NPM by As may protect cells from apoptosis. Over- expression of NPM also improved the cell cycle progression. Over-expression of NPM down-regulates the angiogenesis–related genes, such as VEGF, PDGF-A, TF; but up-regulates the migration factor (uPA) and cell proliferation (PCNA) at transcription level. Taken together, activation of NPM may play a role in arsenic-related bladder carcinogenesis. The clinical significance of NPM in bladder cancer progression needs further investigation in vivo.

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