Description
Tazarotene-induced gene 1 (TIG1), also named as retinoic acid receptor responder 1 (RARRES1), is a retinoid inducible type II tumor suppressor gene; the TIG1B isoform inhibits growth and invasion of cancer cells. Expression of TIG1B is frequently downregulated in various cancer tissues; however, the expression and activities of the TIG1A isoform has yet to be analyzed. This study investigated the effects of TIG1A and TIG1B isoforms on gene expression profiles of colon cancer cells. TIG1A, TIG1B and control stable clones derived from HCT116 colon cells were established using the GeneSwitch system. TIG1 isoform expression was induced upon 5 micro Molar of mifepristone (MFP) treatment for 24 hr. Biological triplicate samples were prepared and gene expression profiles were determined by microarray using human genome HGU133 plus 2 array (Affymatrix). Upon induction of TIG1A and TIG1B expression for 24 hr, a total of 129 and 55 genes were significantly altered, respectively. Of the genes analyzed, 23 and 6 genes were up- and downregulated, respectively in both TIG1A and TIG1B expressing cells.