Genes encoding Pir51, Beclin 1, RbAp48 and aldolase b are up or down-regulated in human primary hepatocellular carcinoma

Abstract

Aim: To reveal new tumor markers and target genes from differentially expressed genes of primary tumor samples using cDNA microarray.

Methods: The (33 )P labeled cDNAs were synthesized by reverse transcription of message RNA from the liver cancerous tissue and adjacent non-cancerous liver tissue from the same patient and used to hybridize to LifeGrid 1.0 cDNA microarray blot containing 8400 known and unique human cDNA gene targets, and an expression profile of genes was produced in one paired human liver tumor tissue. After a global analysis of gene expression of 8400 genes, we selected some genes to confirm the differential expression using Northern blot and RT-PCR.

Results: Parallel analysis of the hybridized signals enabled us to get an expression profile of genes in which about 500 genes were differentially expressed in the paired liver tumor tissues. We identified 4 genes, the expression of three (Beclin 1, RbAp48 and Pir51) were increased and one (aldolase b) was decreased in liver tumor tissues. In addition, the expression of these genes in 6 hepatoma cell lines was also showed by RT-PCR analysis.

Conclusion: cDNA microarray permits a high throughput identification of changes in gene expression. The genes encoding Beclin 1, RbAp48, Pir51 and aldolase b are first reported that may be related with hepatocarcinoma.

Figure 1

Parallel analysis of gene expression in paired human liver tumor sample (A). Histogram analysis of fold change in differentially expressed genes in cDNA microarray (B). Scatterplot of two cDNA microarray analyses of normal liver and liver tumor samples. Each point stands for a gene with the X coordinate value as the gene expression level in the normal liver microarray and the Y coordinate value as the gene expression level in the liver tumor microarray. A R of 0.81 was produced and suggested high reliability of the experiments (C).

Figure 2

Northern blots of RbAp48, Beclin 1 and aldolase b genes in paired liver tumor (T) and normal liver tissues (N). RT-PCR analysis of Pir51 in the same paired HCC samples. 18S rRNA shown as a loading control.

Figure 3

RT-PCR analysis of RbAp48, Beclin 1, Pir51 and al-dolase b expression in one hepato (L02) and 5 hepatoma cell lines (SMMC-7721, Bel-7404, HepG2, Bel-7402, HuH7). β-actin was shown as an internal control.