Cdna Chip In Cancer Research

cDNA microarray (gene chip) is a set of short Expressed Sequence Tags (ESTs) made from a cDNA library of a set of known (or partially known) gene loci, which could be used to detect the expression status of thousands of genes in samples. Recent years, more and more biologists use cDNA microarray to analysis the difference of expression profiles between cancers and homologous normal tissues, in order to find the mechanism of cancers and help clinic.In order to improve the performance of cDNA microarray, we try to use asymmetric PCR instead of conventional PCR to prepare cDNA targets, and Compared hybridization behavior between these 2 approaches. Double stranded targets on the cDNA microarray contain representatives of both the coding and noncoding strands, which will introduce hybridization competition with probes. Here we compared the effect of double and single strands of targets on the signal intensity and the ratios of Cy5/Cy3 within the same slide. The results show that the single stranded targets can increase the hybridization efficiency without changing the ratio of Cy5/Cy3. Based on these results, we established a new strategy by generating cDNA targets with asymmetric PCR instead of conventional PCR to increase the sensitivity of cDNA microarray. Furthermore, we validated the feasibility of this approach. The results indicate that cDNA microarray system based on asymmetric PCR is more sensitive without decreasing the reliability and reproducibility as compared with that based on conventional symmetric PCR.In the study of cancers, we analyzed the expression profiles of acute leukemia, meningioma and prostate cancer. Combined with bioinformatics, statistics and analysis softwares, we picked out a lot of worthy genes, and many of them were first reported in cancers. In a holistic and systematic view, we discussed the progress mechanism of acute leukemia, found a hypothetic pathway of meningioma progression, and described the network interaction of a set of genes which differentially expressed between androgen independent prostate cancer and androgen dependent prostate cancer significantly and related to hormones. In further research, according to the clinic information, we discussed the difference of refractory and non-refractory acute leukemia, subtypes in mengingioma, and androgen independent and androgendependent prostate cancer. Last but not the least, according the specialties of these cancers, we discussed the differentially expressed genes of prostate cancer in hormone and angiogenesis and of meningioma in sexual difference, radiation and HIV effect. Finally, we did a Meta analysis of these expression profiles and found a set of genes significantly differentially expressed in acute leukemia, meningioma and prostate cancer. These genes reflect the disorder status of cancer in cell cycle, proliferation, growth, apoptosis and signal transduction etc. Some genes' functions are still unknown, which are worth to be further studied.