Inflammatory gene mRNA expression in human peripheral blood and its association with colorectal cancer.

Objective: The present study planned to investigate the changes in the mRNA expression of inflammatory genes and their association with colorectal cancer (CRC). Our findings could be useful for noninvasive early screening of CRC patients.

Patients and methods: Venous blood of 20 CRC cases and 15 healthy controls was collected. The mRNA expression of COX-2, TNF-α, NF-κB and IL-6 genes was carried out by using real-time polymerase chain reaction. Relative quantification was done to find out the fold change of these genes.

Results: The mean age of cases and controls was 55 and 50 years, respectively. The ΔCt of COX-2, TNF-α, NF-κB and IL-6 genes was significantly ( p < 0.05) lower in cases as compared to controls. Subsequently, the mRNA expression of these genes was, respectively, 3.56-, 3.4-, 1.71- and 3.86-fold higher in CRC cases as compared to controls. Positive correlation of ΔCt of COX-2 was found with ΔCt of TNF-α ( r = 0.461, p = 0.041) and NF-κB ( r = 0.536, p = 0.015) in CRC cases. The mRNA expression of COX-2 was significantly lower in T2 stage, while mRNA expression of NF-κB was significantly lower in both T2 and T3 stages of CRC as compared to T4 stage.

Conclusion: The increased mRNA expression of COX-2 along with the high mRNA expression of TNF-α, NF-κB and IL-6 genes may be associative risk factors for CRC. COX-2 and NF-κB genes were more expressed in advanced stages of CRC indicating their role in tumor progression. Our findings support the possible role of blood biomarker in the screening of CRC patients in the early stages.