Assessing Mismatch Repair Expression by Immunohistochemistry in Colorectal Adenocarcinoma -Insight from a Tertiary Care Centre.

Background: Microsatellite instability (MSI) is a pattern of hyper mutation that occurs at microsatellite level in the genome and result due to error in the mismatch repair system. MSI is caused by defective mismatch repair (MMR) genes associated with either hyper methylation of MMR genes or BRAF mutations. Anti-MLH-1, anti-MSH-2, anti-MSH-6 and anti-PMS2 monoclonal antibodies are used for Immunohistochemical analysis.

Immune enhancement of nitroreductase-induced cytotoxicity: studies using a bicistronic adenovirus vector.

The nitroreductase (NR)/CB1954 enzyme prodrug system has given promising results in preclinical studies and is currently being assessed in phase I clinical trials. It is well established that there is an immune component to the bystander effect observed with other systems such as thymidine kinase and cytosine deaminase; however, such an effect has not previously been described using NR. We have preliminary data suggesting an immune bystander effect with NR to further examine these effects and their potential enhancement by cytokines, an adenoviral vector containing CMV-NR, an internal ribosome entry site (IRES) and the gene for murine GM-CSF (mGM-CSF) was constructed.