Detection and Localization of Anti and Pro-apoptotic mRNA Genes in Human Colorectal Cancer Using in situ RT-PCR

Problem statement: Recent studies using conventional Polymerase Chain Reaction have shown that anti-apoptotic (Cyclooxygenase-2, COX-2 and Nuclear Factor-κB, NF-κB) and proapoptotic mRNA (Bax and Bad) are involved in the tumorigenesis of colorectal cancer. The aim of this study was to localize the expression of anti and pro-apoptotic mRNA genes using Reverse Transcription in situ Polymerase Chain Reaction (RT in situ PCR) and immunodetection technique in the early stage of human colorectal adenocarcinoma. Approach: Reverse Transcription in situ Polymerase Chain Reaction (RT in situ PCR) and immunodetection technique was applied throughout of this studies. 20 paraffin-embedded tissue blocks of human colorectal adenocarcinoma samples was used compared to controls. Results: Morphologically, the glands and crypts were well-differentiated, enlarged and irregular with active secretion of mucin. COX-2, NF-κB, Bax and Bad mRNA were expressed in both normal and human colorectal cancer tissues. All mRNA genes were expressed in the cytoplasm and nuclei. However, COX-2 and NF-κB mRNA genes were highly expressed with higher intensity of brown staining compared to Bax and Bad at tubular epithelium cells. Conclusion: This study demonstrated that by using RT in situ PCR, COX-2 and NF-κB mRNA genes were shown to be involved in the development of human colorectal cancer.