Experimental study of HSP27 differential expression in left sided colon cancer and right sided colon cancer

To provide molecular genetic basis for oncobiological difference in left sided colon cancer and right sided colon cancer. Differentially expressed proteins in left sided colon cancer and right sided colon cancer were screened by proteomic technique.

Tissue samples including left sided colon cancer and right sided colon cancer were collected and preserved in the -80 degree refrigerator. In the first part of our experiment, protein was separated by 2-dimensional gel electrophoresis (2-DE) and the images of the gels were acquired by the scanner and then analyzed to find the differentially expression protein-spots in different groups. The peptide mass fingerprintings (PMF) was acquired by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and the proteins were identified by data searching in the Mascot-database. Differentially expressed proteins were assayed by RT-PCR,Western blot, and immunohistochemical method.

Altogether 55 differentially expressed protein spots were screened and 21 spots of them were identified. Compared with the right sided colon cancer, 14 proteins were up-regulated and 7 proteins down-regulated including HSP27 in the left sided colon cancer. HSP27 expressed higher in the right sided colon cancer than in the left sided colon cancer.

There are differentially expressed proteins in left sided colon cancer and right sided colon cancer, especially difference in HSP27 expression at mRNA and protein level, which may be molecular genetic basis for oncobiological difference in left sided colon cancer and right sided colon cancer.