論文名稱:

染色體4q基因座在口腔鱗狀上皮細胞癌的變化

 

Cytogenetic alterations of chromosome 4q in oral squamous cell carcinoma

研究生:

張美芳  Mei-Fang Chang

 

(以作者名查詢陽明大學館藏系統)

 

(以作者名查詢全國圖書書目資訊網)

指導教授:

張國威  Kuo-Wei Chang

        學位類別:

碩士

        學校名稱:

國立陽明大學

系所名稱:

口腔生物研究所

            學號:

39017003

          學年度:

91

          語文別:

中文

          出版年:

92

全文說明:

電子全文

        論文頁數:

72

摘要:

  先前用比較基因體雜合術(comparative genomic hybridization, CGH),得知約有40%口腔癌具染色體4q基因缺失(deletion)且與患者預後有關。但目前對4q在口腔癌生成角色尚不明朗。本論文以84q微衛星體,其兩兩間距約為15 cM利用PCR方式及基因定序(genotyping)觀察20個口腔鱗狀上皮癌組織的異質型喪失(loss of heterozygosity, LOH)或是微衛星體不穩定(microsatellite instability, MSI)的情形,以推論出可能之抑癌基因在染色體4q上的位置。首先篩選出國人染色體中告知率(informative rate)75%的微衛星體,進而觀察其在口腔鱗狀上皮癌異質型喪失的發生率。結果顯示有85% (17/20)的口腔鱗狀上皮癌具4q異質型喪失,且集中在4q13.14q22.24q31.224q32.1的位置,顯示這四個區間可能有抑癌基因存在;另口腔鱗狀上皮癌有25%(5/20)4q微衛星不穩定。再者我們製作了陣列-比較基因體雜合術技術(Array-comparative genomic hybridization, Array-CGH),選用1q3q4q及端粒附近(telomere)之人造細菌染色體株(Bacteria artificial chromosome, BAC clone)1900株製作陣列及雜合,進一步精細定位出1q3q4q和端粒附近染色體之缺失或增幅,因各基因座間隔0.25 cM,此實驗可更精細定位抑癌基因的可能位置。初步實驗結果顯示,口腔鱗狀上皮癌在3q及某些端粒有增幅現象,而在1q4q是缺失,因此本研究初步探討了1q4q上潛在抑癌基因的位置,藉此希望更進一步了解這些染色體位置在形成口腔癌的可能角色,且將有助於臨床上的診斷及預後評估,或許能提供一個治療或預防的新方向。

 

We have previously recognized that deletion of chromosome 4q, using comparative genomic hybridization (CGH), existed in 40% of oral squamous cell carcinoma (OSCC) patients, which correlating with their poor prognosis. However, the role of the chromosome 4q in the progression of OSCC is still not clear. Due to their characteristics of loss-of-function by deletion, we proposed that there may be some important tumor suppressor genes locating on this deletion area. In order to define or map the area of the tumor suppressor gene (TSG) on 4q, we selected 8 microsatellite loci as genetic landmarks, with averaging 15 cM in between and having an informative (heterozygosity) rate of 75%. By observing loss of heterozygosity (LOH) or microsatellite instability (MSI) by PCR and genotyping on collected 20 OSCC specimens, we were able to investigate whether deletions has been occurred neighboring to these selected microsatellite loci. If this is the case, we may presume these frequent alteration sites to be potential location of putative TSG. In our OSCC specimens, about 85% (17/20) of LOH were observed in 4q13.14q22.24q31.22 and 4q32.1 loci. Thereby, these four regions should play important roles in carcinogenesis of OSCC and through the effects of functional loss of TSG were highly suspected. Besides, MSI was found in 25% (5/20) specimens. Then we picked 1900 bacteria artificial chromosome clones (BAC clone), constructed from bacteria artificial chromosome clones (BAC clone), constructed from human chromosomes 1q3q4q and telomeric regions, to generate an array and to further map the alterations on chromosome 1q3q4q and telomere area. By array-comparative genomic hybridization (array-CGH) method, we have preliminarily demonstrated amplification in chromosome 3q and some telomeres, and deletion in chromosome 1q and 4q. In conclusion, our current researches may enable us to locate the potential TSG regions on chromosome 4q. By grasping more information underlying the progression of OSCC will facilitate us to predict its clinical prognosis more accurately and maybe allow us to develop future novel therapeutic and preventive strategies.