Rrrm2在斑馬魚皮膚癌化過程中所扮演之角色

根據先前研究得知，在許多腫瘤細胞內shh訊號傳遞途徑會不斷被活化，進而造成細胞癌化而導致癌症的發生。其中基底細胞皮膚癌，basal cell carcinoma (BCC)，就是因為 shh 訊號傳遞途徑發生問題所造成。我們於先前發表的paper中，發現當斑馬魚轉殖品系Tg（K18:shh-RFP）體內Shh過度表現時，會導致皮膚產生癌化現象，之後取其胚胎進行基因晶片（microarray）分析，發現魚體內rrm2基因表現量大幅上升（Chen et al.,2009），因此可知在shh過度表現情形下，會使rrm2被過度活化。在建立另一斑馬魚轉殖品系Tg（K18:rrm2-RFP）過程中，發現部分注射過此質體之魚體於4天大時觀察到頭部、眼睛、胸鰭基部的皮膚發生變異，與野生品系相互比較之後發現此表現型疑似Tg（K18:shh-RFP），則初步懷疑shh與rrm2兩者間可能具關聯性；之後進行相關實驗觀察這些變異的皮膚組織是否與野生品系有不同之處。同時進行胚胎原位雜交反應（whole-mount in situ hybridization）確認rrm2在各個時期表現的訊號位置，結果發現訊號會表現在與細胞週期及細胞增生相關的位置上。為更進一步研究rrm2與shh間的關聯性，將設計實驗推敲及證明兩基因間關係。取野生品系斑馬魚胚胎在發育約5.5小時時，分別浸泡不同濃度的cyclopamine用以抑制shh之功能，以及利用顯微注射（microinjection）技術將過量的K18-shh-RFP質體注射於胚胎內使魚體內shh過度表現，皆收取4天大之樣本，利用胚胎原位雜交反應觀察rrm2的訊號表現，是否會因為shh被抑制或過度活化而明顯降低或增加。假使shh的基因表現與否會影響rrm2訊號表現，將試著搜尋rrm2上下游序列中是否具有Gli結合位，結果發現其上游有疑似Gli結合位的序列，則推測rrm2可能為shh所調控。過度表現的Shh會使rrm2表現增加，使細胞過度增生而可能導致皮膚表皮細胞癌化，本論文將探討rrm2與shh間關係且其在斑馬魚皮膚癌化過程中所扮演之角色。

關鍵字

斑馬魚；皮膚癌化

並列摘要

According to previous studies that shh signaling pathway will continually be activated in many tumor cells and then cause cell carcinoma to lead into cancer. One of the basal cell skin cancer is basal cell carcinoma (BCC) which is caused by shh signaling pathway. In our previous studying, we found that when zebrafish transgenic lines Tg (K18: shh-RFP) Shh overexpress Shh in vivo, it will lead skin to have cancer phenomenon and then take the embryos for gene chip (microarray) analysis. We found rrm2 gene expression significantly increase in fish (Chen et al., 2009), so when shh is overexpressed , it will lead rrm2 into over-activation. We generated the transgenic line Tg(K18:rrm2-RFP) that over-express rrm2 restrictively in the epidermis. We found some variation of the transgenic line by 4 days-post-fertilization(dpf), including that the mutation of head, eyes and the base skin of pectoral fin. Comparing with wild strain found that this phenotype is similar to the transgenic line Tg(K18:shh-RFP), then presume that may have the correlation between shh and rrm2.Through the experiments to test and verify the variety skin tissues that had different between Tg(K18:rrm2-RFP) and wild type(WT).To confirm the expression pattern of rrm2, we can use whole-mount in situ hybridization to display. Observing the expression pattern of rrm2,we found that rrm2 was expressed at the region of developing cell cycle and cell proliferation. Futher,we designed a series of experiment to study the relevance of rrm2 and shh.We use cyclopamine and injected K18:shh:RFP plasmid to change shh expression in vivo.Silimarly,through observed the expression pattern of rrm2 demonstrate that shh was inhibited or overexpressed lead to rrm2 expressed addition or reduction. If rrm2 was effected on shh,we tried to search the Gli binding site at rrm2 upstream or downstream sequences.Then,we found the silimar Gli binding site at rrm2 upstream sequences presumed that rrm2 would be regulated by shh.Shh was overexpressed that it increased rrm2 expression and caused skin carcinogenesis by inducing epidermal cells over-proliferation.In conclusion,we might discuss the connection between rrm2 and shh in this thesis.

並列關鍵字

zebrafish ； skin carcinogenesis ； rrm2

參考文獻

Athar M., Tang X., Lee J.L., Kopelovich L., Kim A.L.（2006） Review Hedgehog signalling in skin development and cancer. Experimental Dermatology 15: 667–677

Bale A.E., Yu K.P.（2001） The hedgehog pathway and basal cell carcinomas. HumanMolecularGenetics,Vol.10, No.7, 757-762

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Chen Y.C.‚ Wang Y.H., Yu T.H., Wu H.J., Pai C.W.（2009） Transgenic zebrafish line with over-expression of Hedgehog on the skin: a useful tool to screen Hedgehog-inhibiting compounds. Transgenic Res.,18(6):855-64

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Rrrm2在斑馬魚皮膚癌化過程中所扮演之角色

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