Overexpression of Wildtype Periostin and Transforming Growth Factor Beta I Genes in Colorectal Carcinoma: A Preliminary Study

The majority of deaths from colorectal carcinoma (CRC) occur due to metastasis during the late stage of tumourigenesis. Recently, periostin, i.e. a gene encoding a protein which is initially found in osteoblasts, has been reported to be associated with the late-stage tumourigenesis in colon and a variety of human cancers. The researchers investigated the expression of periostin mRNA in normal and tumour biopsy specimens using the RT-PCR analysis to elucidate the role of periostin in human colorectal carcinoma. The results showed that there was a significantly (P 0.05) higher expression of the periostin mRNA in the biopsy specimens obtained from the tumour tissues, as compared to the normal tissues. Nevertheless, sequence analysis revealed no mutation in the full length of the periostin gene. As the over-expression of periostin in human colorectal carcinoma did not appear to be due to the mutation in the periostin gene, the involvement of other collaborative factors was therefore deduced. Consistent with this finding, the researchers focussed on studying the transforming growth factor (TGF) b1 which has been reported to be associated with the increasing in the expression of periostin. The analysis (RT-PCR) in this study revealed that TGF- b1 gene was also highly expressed in tumour biopsy specimens (P 0.05). This gene mutation is also absent. These data validated that both periostin and TGF- b1 work together to control colorectal organogenesis.