Fishing for ETV6/RUNX1 fusion and MLL gene rearrangements and their additional abnormalities in childhood acute lymphoblastic leukemia patients of Kashmir

OBJECTIVE

Evidence suggests that ETV6/RUNX1 translocation in pediatric acute lymphocytic leukemia shows geographical variation. Therefore, the present study aimed at unveiling the incidence of ETV6/RUNX1 fusion in pediatric acute lymphocytic leukemia cases of this region using fluorescent in-situ hybridization. Besides, we aimed to determine the incidence of MLL gene rearrangement and the pattern of chromosomal abnormalities in this study group.

METHODS

Samples from 57 acute lymphocytic leukemia cases of pediatric age group were subjected to fluorescent in-situ hybridization and conventional cytogenetic analysis using standard methods.

RESULTS

Conventional cytogenetic analysis revealed chromosomal abnormalities in 19.3% cases. The other major chromosomal abnormalities reported were monosomies in 10.5%, hypodiploidy in 7%, marker chromosomes in 3.5% and deletions in 3.5% cases. We found a 44,XX,-7,-18, r(5), i(17q) complex karyotype in one of the cases. Fluorescent in-situ hybridization analysis revealed ETV6/RUNX1 translocation to be present in 28.07% cases and MLL gene rearrangement in 3.5% cases. 12.5% of ETV6/RUNX1 fusion positive cases were found to have a loss of ETV6 allele. Besides, 8.8% cases were found to exhibit a signal pattern suggestive of RUNX1 amplification. ETV6 gene deletion and MLL gene amplification was detected in 3.5% cases each, of our study.

CONCLUSIONS

Frequency of ETV6/RUNX1 fusion oncogene was found to be higher in pediatric ALL cases of Kashmir region as compared to that reported from other parts of India. Besides, a case was found to have a karyotype viz 44,XX,-7,-18, r(5), i(17q) that has not been reported elsewhere in the childhood ALL.

GSTP1 gene Ile105Val polymorphism causes an elevated risk for bladder carcinogenesis in smokers

BACKGROUND

The glutathione S transferase (GST) family of enzymes plays a vital role in the phase II biotransformation of environmental carcinogens, pollutants, drugs and other xenobiotics. GSTs are polymorphic and polymorphisms in GST genes have been associated with cancer susceptibility and prognosis. GSTP1 is associated with risk of various cancers including bladder cancer. A case control study was conducted to determine the genotype distribution of GSTP1 A>G SNP, to elucidate the possible role of this SNP as a risk factor in urinary bladder cancer (UBC) development and to examine its correlation with clinico-pathologic variables inUBC cases.

MATERIALS AND METHODS

Using the polymerase chain reaction-restriction fragment length polymorphism (PCR- RFLP) approach, we tested the genotype distribution of 180 bladder cancer patients in comparison with 210 cancer-free controls from the same geographical region with matched frequency in age and gender.

RESULTS

We did not observe significant genotype differences between the control and bladder cancer patients overall with an odds ratio (OR)=1.23 (p>0.05). The rare allele (AG+GG) was found to be present more in cases (28.3%) than in controls (24%), though the association was not significant (p<0.05). However, a significant risk of more than 2-fold was found for the variant allele (AG+GG) with smokers in cases as compared to controls (p>0.05).

CONCLUSIONS

Thus, it is evident from our study that GSTP1 SNP is not implicated overall in bladder cancer, but that the rare, valine-related allele is connected with higher susceptibility to bladder cancer in smokers and also males.