Novel association between heterozygous genotype of single nucleotide polymorphism C218T in drug transporter ABCC1 gene and increased risk of colon cancer.

OBJECTIVES: To determine the role of G128C and C218T variants in ABCC1 gene with the risk of developing colon cancer in Jeddah, Kingdom of Saudi Arabia. Methods: This case-control study was conducted on 51 colon cancer patients and 65 controls from King Abdulaziz University Hospital and King Abdullah Medical City in the period from January 2015 to April 2017, and was approved by the Unit of Biomedical Ethics (no: 261-15). Experiments were performed in the experimental biochemistry unit at King Fahd Medical Research Center. The genotype distributions and allele frequencies were determined by polymerase chain reaction-restriction fragments length polymorphism (PCR-RFLP) and DNA sequencing. A Chi-square test was used to determine allele and genotype distributions, odds ratio (OR), risk ratio (RR) and 95% confidence intervals (CI). P-values of less than 0.05 were considered statistically significant. Results: The results showed a novel association between heterozygous (CT) genotype for variant C218T and increased risk of colon cancer [OR=3.4, 95% CI (1.56-7.48), and RR=1.92, 95% CI (1.26-2.93), p=0.002]. These ratios were correlated with high-grade stages (III and IV). In contrast, for variant G128C, there was no significant association with the risk of developing colon cancer. Conclusion: The novel findings of the study revealed that the CT genotype of variant C218T in ABCC1 gene may increase the risk of developing colon cancer.

The effects of a naturally produced benzoquinone on microbes common to flour.

Many species of insects are known to produce and secrete benzoquinone derivatives. These compounds are usually defined as "defense chemicals." However, in many cases, it has not been determined what the chemicals are meant to defend against. Tribolium beetles produce up to three benzoquinones, but their specific function is not known. In this experiment, one of the derivatives, methyl-1,4-benzoquinone (MBQ) was tested for its effectiveness for one of its purported functions as an antimicrobial. Methyl-1,4-benzoquinone was added in three concentrations (0.3, 30, and 150 microg/ml) to the liquid media of three species of Bacillus bacteria and eight species from four genera of yeasts, and the effect on their growth was monitored. The presence of MBQ altered growth in all species. The bacteria responded more negatively than the yeasts. All bacteria species showed reduced growth at all levels of MBQ. Yeasts were more tolerant to the presence of the chemical, and two species, Saccharomyces microellipsoides and Pichia burtonii, actually showed increased growth at the lowest level of MBQ.

Genetic analysis of benzoquinone production in Tribolium confusum.

Many species of tenebrionid beetles produce and secrete benzoquinones from specialized prothoracic and postabdominal glands. Tribolium confusum produces two compounds methyl-1,4-benzoquinone (MBQ) and ethyl-1,4-benzoquinone (EBQ). These compounds are hypothesized to function as external defense compounds, killing microbes and deterring predators, and their ability to evolve by natural selection depends on both selection and the genetic vs. environmental contribution to phenotypic variation. We crossed a strain of T. confusum that produces high quantities of benzoquinones, b-Pakistan, with a low-producing strain, b-+, and measured both the internal and external quantities of MBQ and EBQ for the two extreme strains and their F1 progeny. Internal amounts show a clear pattern of inheritance, with at least 50% of the phenotypic variation attributed to genotype. Additive and dominance coefficients for internal amounts indicate that the trait is additive with no significant dominance. In contrast, external quantities show little pattern of inheritance. The role of genetics and environment in determining quantities of secretory defensive compounds is important to elucidating the ecology and evolutionary potential of chemical defenses.