CXCR4 mRNA expression in colon, esophageal and gastric cancers and hepatitis C infected liver.

We have recently demonstrated by Northern blot and RT-PCR that the mRNA expression of the alpha-chemokine hIRH/SDF-1alpha is reduced in hepatocellular carcinoma (HCC), several digestive tract cancers and premalignant colon adenomas, and that its receptor CXCR4 mRNA expression is reduced in HCC. Here we investigate the expression of CXCR4 mRNA expression in several digestive tract cancers and hepatitis C viral (HCV) infected liver, a premalignant condition. There was no difference in the CXCR4 mRNA expression in colon, esophageal or gastric cancers compared to non-cancerous tissues. This is significantly different from the reduced expression we have seen with hepatocellular carcinoma (p<0.05). To better refine regional tumor or hepatic cytokine mRNA analysis within a biopsy sample we describe a micro-isolation technique for RNA extraction from portal and triad areas of liver biopsies or other small malignant or non-malignant biopsy samples suitable for use in RT-PCR and differential display reactions. In HCV liver biopsies, the expression of hIRH and its receptor CXCR4 mRNA, corrected for G3PDH, was not significantly different from that of control non-HCV (steatosis) biopsies. CXCR4 is expressed on leukocytes and its expression was predicted to correlate with hepatic inflammation. CXCR4 receptor mRNA expression did correlate significantly with that of its ligand hIRH/SDF-1alpha (p=0.001), and with the severity of fibrosis (p<0.05), but not with portal inflammation (p<0.10), piecemeal necrosis (p<0.10), lobular inflammation (p>0.10), the presence of lymphoid aggregates (p>0.10), or the total histological activity index (p=0.07). There was no difference in expression of hIRH or CXCR4 between responders and non-responders to interferon (IFN) treatment, while as a control, the responder group of patients did show a higher expression of IFNalpha receptor than the non-responder group (p=0.05).