Large-scale cDNA transfection screening for genes related to cancer development and progression

Abstract

A large-scale assay was performed by transfecting 29,910 individual cDNA clones derived from human placenta, fetus, and normal liver tissues into human hepatoma cells and 22,926 cDNA clones into mouse NIH 3T3 cells. Based on the results of colony formation in hepatoma cells and foci formation in NIH 3T3 cells, 3,806 cDNA species (8,237 clones) were found to possess the ability of either stimulating or inhibiting cell growth. Among them, 2,836 (6,958 clones) were known genes, 372 (384 clones) were previously unrecognized genes, and 598 (895 clones) were unigenes of uncharacterized structure and function. A comprehensive analysis of the genes and the potential mechanisms for their involvement in the regulation of cell growth is provided. The genes were classified into four categories: I, genes related to the basic cellular mechanism for growth and survival; II, genes related to the cellular microenvironment; III, genes related to host-cell systemic regulation; and IV, genes of miscellaneous function. The extensive growth-regulatory activity of genes with such highly diversified functions suggests that cancer may be related to multiple levels of cellular and systemic controls. The present assay provides a direct genomewide functional screening method. It offers a better understanding of the basic machinery of oncogenesis, including previously undescribed systemic regulatory mechanisms, and also provides a tool for gene discovery with potential clinical applications

Transcription of the putative tumor suppressor gene HCCS1 requires binding of ETS-2 to its consensus near the transcription start site

“…The HCCS1 gene was identified as a candidate tumor suppressor gene in the hepatocyte lineage [3,4] and is often mutated and aberrantly expressed in liver cancers [3,5]. This gene is well conserved in evolution and may have a role in membrane trafficking, as suggested by the presence of a Vps53_N domain in its amino-terminus (http://www.…”

“…ncbi.nlm.nih.gov/Structure/cdd/cddsrv.cgi?uid=9659) [18]. However, we remain ignorant of the exact role of the HCCS1 gene in human carcinogenesis [3,4]. The ubiquitous pattern of overexpression in the established tumor cell lines ( Figure 1A) implies that mechanisms other than control of its transcription are likely involved in the aberrant HCCS1 function in human liver cancer [3,4].…”

“…However, we remain ignorant of the exact role of the HCCS1 gene in human carcinogenesis [3,4]. The ubiquitous pattern of overexpression in the established tumor cell lines ( Figure 1A) implies that mechanisms other than control of its transcription are likely involved in the aberrant HCCS1 function in human liver cancer [3,4]. It may be faulty in liver cancer cells because of mutations [5] and alternative splicing, as suggested by the presence of at least four spliced forms of this protein in the liver cancer cell lines (unpublished results).…”

“…A better understanding of the genetic and epigenetic aberrations associated with HCC is expected to lead to a significant improvement in the clinical management of this malignancy [2]. The hepatocellular carcinoma suppressor 1 (HCCS1) gene (AF246287) was identified by both positional cloning from a predominant loss of heterozygosity region (17p13.3) in liver cancer [3] and by functional screening for genes affecting cell proliferation in large-scale transfection assays [3,4]. Its overexpression results in inhibition of cell proliferation in cell culture and tumor growth in nude mice [3].…”

Finding a novel interacting protein of the hepatic carcinoma related gene MIP: NF-κB essential modulator (NEMO)

“…Cancer related gene MIP (GeneID: 727764) was cloned through chromosome structure comparing between normal liver tissue and hepatic carcinoma tissue, subtractive hybridization and large scale colony formation screening by Shanghai Cancer Institute (1). Earlier studies showed that MIP could inhibit the growth of cancer cells and growth rate decreased by about 50% when MIP was transfected into HeLa cells.…”