The transcriptional activity profile of inhibitor apoptosis protein encoding genes in colon cancer patients: A STROBE-compliant study

The inhibitor of apoptosis family proteins (IAPs) plays a crucial role in the process of carcinogenesis by regulating apoptosis and maintaining the tissue balance. In this study, a transcriptomic analysis of IAP-encoding genes in colon cancer was performed using oligonucleotide microarrays. Adenocarcinoma and healthy colon tissue samples were collected from 32 patients (16 females and 16 males) who underwent surgery due to colon cancer. The mRNA was extracted from tissue samples and tested using oligonucleotide microarrays (Affymetrix). The results were validated using the qRT-PCR technique. Hierarchical grouping was used to allocate 37 samples of normalized mRNA concentrations into 4 groups, with statistically significant differences in gene expression between these groups. The group of genes associated with colon cancer, including IAP-encoding gene - BIRC5 (Survivin), was selected for further testing. Our study confirmed an increased expression of BIRC5 in colon cancer tissue when compared to the control group. Increased levels of Neuronal Apoptosis Inhibitory Proteins were detected only in low-stage colon cancer, while the expression of Human X Chromosome-Encoded inhibitor of apoptosis family proteins decreased in colon cancer. The transcriptional activity of IAP-encoding genes varied, depending on the severity of colon cancer. The concentration of mRNA, encoding BIRC5 was elevated in samples obtained from more advanced colon cancer. Hence BIRC5 could be used as a complementary parameter for the diagnosis and prognosis of colon cancer.