Decreased expression of the SIN3A gene, a candidate tumor suppressor located at the prevalent allelic loss region 15q23 in non-small cell lung cancer.

Lung Cancer, 2007

1: 2007 Sep 11; [Epub ahead of print] Decreased expression of the SIN3A gene, a candidate tumor suppressor located at the prevalent allelic loss region 15q23 in non-small cell lung cancer.
To identify the tumor suppressor genes (TSG) associated with non-small cell lung cancers (NSCLC), we performed the loss of heterozygosity (LOH) analysis in NSCLC samples from 66 patients.
The SIN3A gene product is a component of the histone deacetylase (HDAC) complex and plays essential roles in early embryonic development and the proliferation and survival of a variety of cells through the repression of diverse signaling pathways.
Our expression analysis revealed more frequent down-regulation of the SIN3A mRNA in 19 of 31 cases (61%) of NSCLCs in comparison to those of other flanking genes (16-42%), albeit the correlation of the decreased expression with the LOH did not attain statistic significance.
These results suggest that the attenuated function of SIN3A due to a decreased level of expression may result in epigenetic de-regulation of growth-related genes through histone acetylation, which leads to the tumorigenesis of lung cancer cells.
To our knowledge, this is the first evidence of the down-regulation of the SIN3A gene in human cancer.