Identification Of Differentially Expressed Genes In Hepatocellular Carcinoma By Laser Capture Microdissection And Microarray

Objectives:Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. In China, it ranks the third in cancer incidence and the second in tumor related mortality. Because of the low survival rate and high recurrence rate in advanced cases, early detection and diagnosis are the keys for the treatment. Laser capture microdissection (LCM) and microarray are two new immerging techniques in post-genome era. LCM under direct microscopic visualization permits rapid one-step procurement of specific populations of benign and malignant cells, and thus solves the problem of tissue heterogeneity. Gene expression microarray can assess the expressions of a large number of genes simultaneously, and catch small amount of mRNA directly, and therefore provides a highly powerful tool. The aim of this study is to identify the HCC-associated genes by constructing transcription profiles of pure HCC tissues and normal liver tissues with the combination of these two techniques.Materials and Methods: HCC cells and normal liver cells were laser capture microdissected. Micro-RNA was isolated from these cells. Agilent 2100 Bioanalyzer was used to determine their concentrations and quality. After linear amplification and two-color fluorescent-labeled,the cRNA was hybridized with Agilent human 4*44K whole genome microarray, then was washed and scanned. The Feature Extraction Software was used to normalize the signals. Thus differentially expressed genes were screened. All the genes expressed in the four paired samples were analyzed and classified. The ten top ranked up- and down-regulated genes were studied.Results: Compared the gene expression profile with normal liver tissues, HCC had 1361 differentially expressed genes, with 607 being up-regulated and 754 being down-regulated respectively. Among the ten top ranked up- and down-regulated genes (totally 20), 6 genes were known HCC differentially expressed genes, 10, known other cancer expressed genes in literature. Only 4 were unknown differentially expressed genes of HCC and other cancers.Conclusion: (1) Combining laser capture microdissection and microarray is an effective approach for identification of differential gene expression profiles. (2) Further study on these differentially expressed genes may provide a novel approach for the diagnosis and treatment of HCC.