Abstract: Objective To study the expression of malignant melanoma(MM) related genes by cDNA microarray technique. Methods mRNA, extracted from tissues of patients and normal controls, was reversely transcripted into cDNA and marked with 33P. The cDNA probes were hybridized to cDNA microarrays, which contained 2000 human genes each array. The down-regulation of two co-differentiated expressed genes was confirmed by quantitative real-time RT-PCR. Results Different expression between MM and normal controls was found in 4.7%-6.15% of genes by more than 2 times,0.75%-1.4% by more than 5 times, and 0.45-0.5% by more than 10 times. These genes were pro-oncogenes, tumor suppressor genes, genes related to apoptosis, cell cycle related genes, and so on. Three genes were down-regulated in all of the patients. Two of those genes, histidine triad nucleotide-binding protein (HINT) and RBP1-like protein (BCAA), were down-regulated, as identification by quantitative real-time RT-PCR. Conclusions cDNA microarray can be used effectively to reveal melanoma gene expression profiling for the propose of carcinogenesis study. HINT and BCAA are the first reported genes down-regulated in MM. However, further studies are needed for their expressive specificity and mechanism in MM.

Key words: Melanoma, Oligonucleotide array sequence analysis, Reverse transcriptase polymerase chain reaction