Investigation of the interaction between Lactococcus lactis M4 and human colorectal cancer cell lines, SW620

• Main Author: Lau, Yi Siang
• Format: Project Paper Report
• Language: English
• Published: 2015
• Online Access: http://psasir.upm.edu.my/id/eprint/91039/1/FBSB%202015%20149%20-%20IR.pdf; http://psasir.upm.edu.my/id/eprint/91039/

Lactic Acid Bacteria (LAB) are frequently used in food fermentation and probiotic dairy products. They are known to be beneficial to the human gut microflora have a Generally Regarded as Safe (GRAS) status. In recent years, there has been a resurgence of interests of scientists to develop LAB as therapeutic vaccine carriers to target cancer cells. To assess the potential of LAB as a DNA delivery vehicle, interactions of the LAB strains with the cancer cell lines need to be investigated. The interactions of a local dairy strain, Lactococcus lactis M4 was compared with a chicken intestine derived reference strain, Lactobacillus spp. CI314 against human colorectal cancer cell lines SW620 at multiplicity of infection (MOI) 250 bacteria per cell. Both rate of adhesion and invasion of M4 strain were significantly higher than CI314 strain. In an alternative adhesion assay using crystal violet staining, M4 strain had also shown a significantly higher adhesion rate when compared to CI314. However, interaction assay at higher MOI (500:1) of M4 strain shows cytotoxicity effect towards SW620 cell lines when compared to the control cells. Cell viability assessment via trypan blue counting had shown a low cell recovery rate, suggesting SW620 cell detachment from the monolayer. Based on the promising invasion and adhesion results from the interaction assay, it can be concluded that L. lactis M4 is a potential candidate to be developed into a DNA delivery vehicle.