Since then, although molecular detection methods based on gene mutation determination have been carried out for several years, the clinical utility of the many molecular markers and their clinical applications remain limited for colorectal cancer patients. Therefore, there is real need for new molecular markers to improve tumour subclassification and prediction of clinical outcome. Inhibitors,research,lifescience,medical Microarray technology and gene expression profiling studies in colorectal cancer stimulated an interest in potential results that could be directly used in the routine clinical setting. Gene expression signatures

predictive of disease outcome and response to adjuvant therapy have been generated and are being evaluated in the clinical setting. Such molecular diagnostics and their promise of tailored therapy generated much excitement among researchers however they have yet to be fully incorporated into today’s standard of care as they are limited by difficulties in reproducibility, standardisation and lack proof of significance beyond traditional prognostic tools. One of the primary aims of this study was to characterise Inhibitors,research,lifescience,medical the Inhibitors,research,lifescience,medical expression profiles of candidate genes in colorectal tissue. Rigourous evaluation of appropriate genes with which to normalise real-time quantitative PCR data see more identified PPIA and B2M as the most

stably expressed genes in colorectal tissue samples. This enabled the development of a robust experimental approach which ensured that subsequent profiling of gene expression levels would be measured accurately and reproducibly in colorectal tissue. As a result, a comprehensive list of genes with highly differential

expression patterns was derived. CXCL12 and its receptors CXCR4 and CXCR7 The first candidates Inhibitors,research,lifescience,medical to be examined were the chemokine CXCL12 and its receptors CXCR4 Inhibitors,research,lifescience,medical and CXCR7, whose gene expression levels were, determined in 107 tumour and tumour associated normal colorectal tissues, the largest patient cohort reported to date. Significant down-regulation of CXCL12 in tumour compared to normal colorectal tissue was found, in contrast to CXCR4, which showed non-significant up-regulated expression levels in tumour tissues. The reduced expression of CXCL12 was noticed in both polyps and tumours. This could be explained by the role of CXCL12 in tumour immunology; however, it may highlight a possible tumour suppressor function of this gene. Investigation of the interaction between CXCL12, CXCR4 and CXCR7 not may provide some understanding of their functions and the role of each gene in regulating the expression of the others. Despite the reciprocal patterns of expression, strong positive correlation of CXCL12/CXCR4 and CXCL12/CXCR7 in both tumour and normal colorectal tissue was found. Moreover, CXCR4 and CXCR7 expression patterns correlated in the same manner. Saigusa et al. also reported significant positive correlation between expression levels of CXCL12 and CXCR4 in patients with rectal cancer who underwent preoperative CRT.