The Prevalence of CHEK1 and CHEK2 Mutations in Prostate Cancer: a Retrospective Cohort Study.

Background: Prostate cancer (PCa) is one of the most common types of cancer among men. Mutations and accumulation of chromosomal deviations are correlated with the development and aggressiveness of PCa. Cell cycle checkpoint pathways and DNA repair mechanisms are reported to deviate in cancers. Mammalian checkpoint kinase 1/2 (CHEK1/CHEK2) genes act as key signal transducers inside the genomic integrity checkpoints. CHEK1 and CHEK2 gene mutations were reported in a few different types of cancers. In PCa, CHEK2 mutations were studied, but CHEK1 gene variations were not well investigated. Objective: This study aimed to investigate the occurrence of variations in the CHEK1 and CHEK2 genes in PCa in the Jordanian population. Methods: Formalin-fixed paraffin-embedded PCa specimens of radical prostatectomy surgical procedures from 74 Jordanian patients were subjected to DNA extraction, polymerase chain reactions and Sanger sequencing to screen the mutations in selected exons of CHEK1 and CHEK2 tumor suppressor genes. Results: The presence of F281L (T/C) (1.4%) homologous missense point mutation in the kinase domain of the CHEK2 gene and P188P (1.4%) silent point mutation in the kinase domain of the CHEK1 gene. In addition, the 1100delC mutation was not detected in the studied PCa specimens. Conclusion: In line with previous reports, the presence of CHEK2 mutation with a frequency of 1.4% supported the possible role of genetic variants of this gene in the development of PCa. No 1100delC mutation was detected in this study. No association was found in this study between CHEK1 mutations and the development of PCa. Further studies are needed with larger cohorts along with a screening of more exons in order to shed more light on the frequency of CHEK2 gene mutations and their role in the development of PCa in Jordan.

Association between MTHFR 677C>T Polymorphism and Vitamin B12 Deficiency: A Case-control Study.

BACKGROUND: Vitamin B12 (cobalamin) deficiency is a prevalent worldwide health concern. Several factors are associated with vitamin B12 deficiency including lifestyle, genetic predisposition, and malfunctions in the absorption and transport of vitamin B12. In the current case-control study, we aimed at investigating the association between MTHFR polymorphisms and vitamin B12 deficiency in a Jordanian population. METHODS: Two polymorphic sites of the MTHFR gene (c.677C>T, rs1801133 and c.1286A>C, rs1801131) were analyzed using RFLP and DNA sequencing in a group of vitamin B12 deficient individuals (45 males and 55 females). As a control, 100 matching individuals (age and sex) with vitamin B12 levels > 200 ng/mL were also recruited for this study. RESULTS: The MTHFR c.677C>T variant was significantly associated with vitamin B12 deficiency in individuals from northern Jordan. The frequency of the homozygous MTHFR c.677C>T genotype was significantly higher in B12 deficient individuals in comparison with the control group (X2 = 8.397, p = 0.0150). The T allele frequency showed significant association with vitamin B12 deficiency in the study population (OR= 1.684, 95% CI: 1.116 to 2.542, p = 0.017). On the other hand, the MTHFR c.1286A>C variant did not show significant association with vitamin B12 deficiency in the selected population. CONCLUSIONS: Our results showed a significant association between homozygous MTHFR c.677C>T variant and T allele frequencies and vitamin B12 deficiency in the Jordanian population.