Tetra-primer Amplification Refractory Mutation System Research Articles

Multiplex Tetra-Primer Amplification Refractory Mutation System PCR to Detect 6 Common Germline Mutations of the MUTYH Gene Associated with Polyposis and Colorectal Cancer

We describe a simple tetra-primer amplification refractory mutation system PCR (T-ARMS-PCR) for detecting MUTYH mutations, which are associated with colorectal adenomas and colorectal cancer. We designed specific T-ARMS-PCR assays for 6 mutations (Y165C, G382D, 1395_7delGGA, Y90X, 1103delC, and R231H) selected on the basis of the frequency of their occurrence. We also designed a set of 3 multiplex T-ARMS PCR assays, each for detection of 2 mutations. We tested DNA samples from patients with attenuated or classic adenomatous polyposis coli and no detectable APC germline mutations. All mutations were easily detected with both the specific and multiplex T-ARMS-PCR assays. Results were confirmed by DNA HPLC analysis in all 54 patients, and each mutation was confirmed by direct DNA sequencing. T-ARMS-PCR does not require any special equipment, and it provides rapid, reproducible, and cost-effective detection of common MUTYH mutations. Multiplex T-ARMS-PCR allows the detection of 6 common MUTYH mutations with use of as few as 3 single tube PCR reactions. It could be useful to carry out large population-based epidemiologic studies.

JAK2 V617F Tyrosine Kinase Mutation in Leukemia Cell Lines.

It has recently been shown that the majority of patients with polycythemia vera, and substantial numbers of patients with idiopathic myelofibrosis and essential thrombocythemia, carry a single nucleotide mutation in the JAK2 gene. The JAK2 V617F mutation was also found in patients with other myeloproliferative disorders, though at lower percentages. The JAK2 point mutation may contribute to the development of these diseases, and the elucidation of the cellular function of mutated JAK2 might facilitate the development of a suitable drug. In numerous cases, the effects of a mutationally altered protein on cellular functions like proliferation, differentiation or apoptosis, have been revealed using immortalized cell lines that carry the mutation in question. To find such a model system for JAK2 V617F in hematopoietic neoplasia, we tested a panel of 37 cell lines from patients with myeloproliferative disorders, myelodysplastic syndromes (MDS) and the megakaryoblastic variant of acute myeloid leukemia (AML M7) and compared these with cell lines derived from other types of AML (M1-M6), and acute lymphoblastic leukemia (ALL). Cell lines were tested for JAK2 V617F expression applying a DNA tetra-primer amplification refractory mutation system (ARMS), a method that specifically amplifies the normal and mutant sequences plus a positive control band in a single reaction. According to this method, three cell lines carried the JAK2 V167F mutation:cell line MB-02 derived from a patient with a history of myelofibrosis and myeloid metaplasia that developed into AML M7;cell line MUTZ-8 established from a patient with AML M4 25 years after onset of MDS;cell line SET-2 from a patient at the stage of leukemic transformation of essential thrombocythemia.We present data on these cell lines including JAK2 ARMS and sequencing results, cytogenetic analysis focusing on chromosome 9, and JAK-2 protein expression and activation. In summary, we detected three leukemia cell lines that carry the recently discovered JAK2 mutation. These cell lines promise to represent important research tools in the further analysis of this genetic alteration.

Genetic polymorphisms in cell cycle regulatory genesMDM2 andTP53 are associated with susceptibility to lung cancer

The tumor suppressor TP53 pathway plays a crucial role in preventing carcinogenesis through its ability to impose cell cycle arrest and apoptosis following DNA damage and oncogene activation. MDM2 is a key negative regulator of the TP53 pathway and is overexpressed in many cancers as oncoprotein. We investigated the association between genetic variation in the promoter region of MDM2 (c.-5+309G>T, rs2279744:g.G>T) and the coding region of TP53 (c.215G>C, rs1042522:g.G>C, designated Arg72Pro) and the risk of developing lung cancer. The genotypes of 1,106 patients and 1,420 controls were determined by tetra-primer amplification refractory mutation system (ARMS)-PCR or PCR-based restriction fragment length polymorphism (RFLP). Associations with risk of lung cancer were estimated by logistic regression. We observed an increased lung cancer risk associated with the MDM2 GG (odds ratio [OR] = 1.83, 95% confidence interval [CI] = 1.45-2.32) and TG (OR = 1.33, 95% CI = 1.09-1.63) genotypes. An increased risk was also associated with the TP53 Pro/Pro genotype (OR = 1.47, 95% CI = 1.17-1.85, P = 0.003) compared to the Arg/Arg genotype. The gene-gene interaction of MDM2 and TP53 polymorphisms increased lung cancer risk in a supermultiplicative manner (OR for the presence of both MDM2 GG and TP53 Pro/Pro genotypes = 4.56, 95% CI = 2.76-7.54). Significant interactions were observed between these polymorphisms (respectively and jointly) and smoking (OR = 10.41, 95% CI = 5.26-20.58) for smokers with both the MDM2 GG and TP53 Pro/Pro genotypes. In conclusion, genetic polymorphisms in cell cycle regulatory genes MDM2 and TP53 contribute to the risk of developing lung cancer.