Abstract:

Objective To screen for genes associated with low-dose UVA irradiation-induced adaptation reaction in cultured human melanocytes, and to explore the molecular mechanism of the adaptation. Methods Cultured human melanocytes of fifth to tenth passage were divided into two groups, experimental group was subjected to an irradiation with UVA at 7.2 J/cm2 once daily for 4 times and an additional irradiation at a lethal dose of 86.4 J/cm2 6 hours after the above 4-session irradiation, and control group subjected to a single irradiation with UVA at 86.4 J/cm2. A human genome-wide oligonucleotide chip was used to screen for differentially expressed genes between the two groups of cells followed by a functional classification based on international standard. Moreover, a part of these genes were analyzed and identified by real-time fluorescent quantitative PCR. Results In the adaptation reaction induced by low-dose UVA irradiation in cultured melanocytes, there were 129 differentially expressed genes, including 81 up-regulated genes and 48 down-regulated genes. These genes were found to be mainly involved in metabolism，transport, signal transduction, apoptosis, DNA synthesis and repair, and some of them were oncogenes or anti-oncogenes. Real-time PCR confirmed some of the differentially expressed genes. Conclusions The whole genome-wide oligonucleotide chip could screen with high efficiency for differentially expressed genes in low-dose UVA irradiation-induced adaptation reaction in cultured melanocytes.

Key words: mRNA differential expression