Carmina V. Carmina | Kristina Carmela Aguilar | Ana Maria D. Carino | Allan Fellizar | Antonio Lim | Lara Angeles | Lorenzo Abanilla | David Angelo Guanzon | Pia Marie Albano
Colorectal cancer (CRC) ranked 4th cause of cancer-related death in the world and 3rd leading cause of malignancy in the Philippines in 2018. Among the established risk factors are advancing age, family history of cancer, high fat diet, sedentary lifestyle, smoking, and alcohol. Over the past few years, there has been a growing interest in the role of the members of the gut microbiota, including Escherichia coli, in colorectal cancer development. Some E. coli strains may carry the pks pathogenicity island, which encodes the compound colibactin that is believed to alkylate DNA on adenine residues and induce double-strand break. Thus, this study aimed to determine the possible association of pks+ E. coli with CRC development among selected Filipino cases. A total of 62 formalin-fixed paraffin-embedded (FFPE) colorectal tissues positive for cancer cells (cases) matched with 62 cancer-free tissues (controls) were analyzed for the presence of uidA, clbB, clbN and clbA genes using an in-house developed real-time qPCR. Results show that there is no significant difference (p>0.05) between the cases and controls in terms of the prevalence of the uidA gene, which is an important target for the detection of E. coli. As to the markers of the pks pathogenicity island, clbN gene was more prevalent (p<0.05) in cancer-free tissues than in malignant colorectal samples. No significant difference (p>0.05) was observed between cases and controls in terms of the prevalence of the clbA and clbB genes. Therefore, pks+ E. coli may not be a risk factor in CRC development among Filipinos.
ISSN 2719-1990 (Print)
Philippine E-Journals
