| Laryngeal carcinoma is common malignant tumor in upper respiratory tract, its morbidity is sixth in human tumor. Laryngeal carcinoma is very common in Northeast China these years, and shows a tendency of increasing incidence, likes other human tumors, initialing and progression of laryngeal carcinoma is a multi - procedure course involved many kinds of genetic changes, one of the most important way is activation of oncogene and inactivation of tumor suppressor gene, usually companied with abnormality of chromosome, those unrandom abnormalities include lose, gain, deletion, re - arrangement and abnormal replication, amplification and so on. Activation of oncogene and loss of functions of tumor suppressor genes resulting from instability of human genome is one of the mechanisms in tumorigenesis. So, applying advanced molecular cellular genetic techniques to search chromosomal abnormalities as well as finding related abnormal genes, and studying changes of those genes in tumorigenesis, is important to our further understanding on tumor origin, progression, and biological behaviors. Kallionimi and his accompanies found a kind of molecular cellular genetic technique, CGH (comparative genomic hybridization) , which is based on SSH ( suppression subtractive hybridization) and FISH (fluorescence in situ hybridization ). Method is easy, CGH is applied extensively, and one examination can obtain detailed information of whole genomic changes, so CGH becomes a heated focus. Because genetic dates of laryngeal carcinoma researching is limited, in order to discuss chromosomal changes of laryngeal carcinoma, this study analyze 18 cases of laryngeal carcinoma by CGH, finds a mass of unbalanced zones of chromosome, provides some examination basis for pathogenesis and mechanism of laryngeal carcinoma.Materials1. Tumor sample2. DNA extraction related agents3. CGH related agentsMethodsGenomic DNA were extracted from cancer tissues and peripheral blood of normal person, then they are signed with different color (red, green) fluorescence by nick translation, and hybridize in situ with metaphase chromosome of normal person peripheral blood, and examine respectively. Fluorescence chromosome images of each case of laryngeal carcinoma are acquired by fluorescence microscope equipped with cool CCD camera, profiles of each case are acquired by analyzing those images with QCGH software ( Leica Company). Each case are analyzed at least 5 high quality karyotype, and acquire copy number gain and loss of whole chromosome.ResultsOn the basis of fluorescence chromosome images and profiles, we analyzed 18 laryngeal carcinomas with CGH. Results show that each one has different degree of variances, included gains and losses of partial and whole chromosome. Each case has 12.9 abnormal regions averagely, losses are more than gains, e-qual to 7. 2 and 5. 7 per case respectively. Main regions are gains in chromosomes 3 q (78%),5p(61%),llq(56%),lq(50%),8p(44%),8q(39%) and 15q (39% ) , and losses of 3p(70% ) ,5q(78% ) ,9p(67% ) ,13q(50% ) , 1lp(44% ) and 14q(39% ). There are many specific gains and losses in several chromosomes, especially the increase of copy number karyotype in 1p13 -21 (8/18) ,3p21 - 23 (14/18), 5p21 - 22 (14/18 ), 9p12 - pter (10/18) and 13q21 -31 (8/18), while the decrease in lqll - 21 ( 11/18) ,3ql5 -21(12/18),8P22-24(6/18),llql2-13(8/18),15q21 -23(7/18) 18p11(8/ 18) are common.ConclusionThis research analyzes 18 case laryngeal carcinoma samples, and discovers that there are unrandom DNA copy number gain and loss sites in chromosome, show these sites may include candidate oncogene and tumor suppressor gene. CGH are applied to analyze DNA level changes of chromosome, can get good results and can be repeated well, it is an advisable way of tumor cellular genetic research.
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