Clinical Significance of FLT-3 Internal Tandem Duplication and D835 Mutations in Acute Myeloid Leukemia Patients from West Indian Population

Introduction:The FMS-like tyrosine kinase-3 (FLT3), a member of the Platelet-derived growth factor (PDGF-R) subfamily of receptor tyrosine kinases, expressed on early hematopoietic progenitor cells play an essential role in survival and differentiation of stem cell. Majority of acute myeloid leukemia (AML) patients have mutation in this gene. Two types of frequent mutations are present in this gene. Both the types FLT3-ITD and D835 mutations play an important role in prognosis of AML patients. Methods:Total 33 patients were enrolled in the study. Blood samples were collected from the subjects, from which the DNA isolation was carried out.For FLT3-ITD mutation, PCR was performed and for D835 mutation PCR-RFLP was performed. DNA segments were amplified using Polymerase Chain Reaction (PCR). Results: FLT-3 ITD mutation was detected in 12% of patients and D835 mutation was detected in 3% of patients. The study revealed significant correlation between ITD and Tdt, while D835 negatively correlated with CD33, HLADR and Tdt. However, there was no substantial correlation of D835 with LDH value. also revealed that FLT-3 ITD significantly correlated with LDH values in AML patients. The mean value of LDH was 753.45 IU/L in ITD positive patients as compared to ITD negative patients with 338 IU/L mean LDH value, suggesting higher LDH values in ITD positive. Conclusion:These Genotypic analysis of FLT-3 mutation results from West Indian population provide important tools for understanding of AML pathogenesis and determination of appropriate therapeutic intervention. Further large number of patient data can also corroborate these significant results.

XRCC2 and XRCC3 Polymorphisms and Breast Cancer - A Case-Control Study from West India

Background:The double strand break repair pathway, comprising XRCC2 and XRCC3 has crucial role in maintenance of genomic stability and prevention of tumor initiation and progression. Therefore, sequence variants of such DNA repair genes may compromise individual's DNA repair capacity and can influence risk of developing breast cancer. Method and Results:To estimate the impending effect of XRCC2 (Arg188His) and XRCC3 (Thr241Met) polymorphisms on breast cancer, 133 breast cancer patients and 154 healthy controls were evaluated by PCR-RFLP method. In the present study, it was noted that there was no significant correlation between these polymorphisms and breast cancer risk. However, within patient group, significant association of XRCC2 variants with PR negative breast cancer was detected. Further, patients with XRCC2 variant genotypes were also at high risk of developing TNBC and Her2 enriched subtypes as compared to luminal A subtype. Significant relation was also obtained between XRCC3 variants and large sized and infiltrative breast tumors. Conclusion: These noteworthy observations demonstrate potential involvement of XRCC2 and XRCC3 polymorphisms in pathophysiology of breast cancer.

A Sole t(10;19)(p11.2;p12) in AML-ETO negative AML-M2 paediatric patient: First novel case from India

Acute myeloid leukemia (AML) is a heterogeneous group of disorders with regards to its pathology and molecular genetics features. The translocation t(8;21)(q22;q22), which results in the fusion of the AML and ETO genes, is a recurrent aberration in AML, preferentially correlated with FAB- M2, and has the highest incidence in childhood AML. Because of the favorable prognosis, the evidence of the t(8;21) or the AML1-ETO fusion gene is mandatory in most of the therapy trials, allowing the stratification of the patients to the correct risk group in terms of treatment. Here, we describe a novel case of sole translocation t(10;19)(p11.2;p13) in a AML1-ETO negative AML-M2 patient. In general, this translocation is previously observed with combination of complex translocations, but sole abnormality was not previously observed. This is a novel translocation and not observed previously as a sole abnormality in any AML case. Hence, the functional role of this translocation is still unknown. Short term bone marrow culture was carried out for conventional cytogenetics and karyotype was 46, XX,t(10;19)(p11.2;p12) in all 20 metaphases analyzed. To confirm this translocation FISH with Whole chromosome paint probe was applied and results confirmed the translocation between chromosome 10 and 19. To the best of our knowledge, this is the first novel case of sole t(10;19) in a paediatric AML-M2 patient with AML-ETO negative fusion. Patient expired within a week. Therefore, the present case challenges the view that the occurrences of sole and new novel translocation require more such cases to be studied in large cohort which is generally an indication for poor prognosis.

Trisomy 8 in leukemia: A GCRI experience.

Trisomy of chromosome 8 is frequently reported in myeloid lineage disorders and also detected in lymphoid neoplasms as well as solid tumors suggesting its role in neoplastic progression in general. It is likely to be a disease-modulating secondary event with underlying cryptic aberrations as it has been frequently reported in addition to known abnormalities contributing to clinical heterogeneity and modifying prognosis. Here, we share our findings of trisomy 8 in leukemia patients referred for diagnostic and prognostic cytogenetic assessment. Total 60 cases of trisomy 8, as a sole anomaly or in addition to other chromosomal aberrations, were reported (January 2005–September 2008). Unstimulated bone marrow or blood samples were cultured, followed by GTG banding and karyotyping as per the ISCN 2005. Patients with +8 were chronic myeloid leukemia (CML) (36), acute myeloid leukemia (AML) (17), and acute lymphoblastic leukemia (ALL) (7). In 7 patients, trisomy 8 was the sole anomaly, whereas in 6 patients +8 was in addition to normal clone, in 47 patients, the +8 was in addition to t(9;22), t(15;17), and others, including 3 with tetrasomy 8. Only one patient showed constitutional +8. The present study will form the basis of further cumulative studies to correlate potential differential effects of various karyotypic anomalies on disease progression and survival following a therapeutic regime. To unravel the role of extra 8 chromosome, constitutional chromosomal analysis and uniparental disomy will be considered.

Utility of urinary biomarkers in oral cancer.

OBJECTIVE: Oral cancer is the leading malignancy in India, with tobacco playing a major role in the etiology. The aim of the present study was to quantify nitrate+nitrite (NO2+NO3) in tobacco products as well as to study tobacco exposure related biomarkers in controls, patients with oral precancers (OPC) and oral cancer patients. MATERIALS & METHODS: Healthy individuals (n=90) were grouped into without habit of tobacco (NHT, n=30) and healthy individuals with habit of tobacco (WHT, n=60). Oral cancer patients with a tobacco habit were classified into abstinence (n=62) and non-abstinence (n=64) groups according to status at the study time. Urinary nicotine and cotinine levels were analyzed by modified high-pressure liquid chromatography (HPLC) using a UV detector. Levels of NO2+NO3 in tobacco and urine, and urinary thioether levels were estimated by spectrophotometry. RESULTS: NO2+NO3 levels in different types of tobacco product ranged between 0.13 to 3.39 mg/g. The Odds Ratio (OR) analysis indicated positive associations of both smoking and chewing habits of tobacco with high risk of development of oral cancer. Urinary nicotine, cotinine and NO2+NO3 levels were significantly elevated in WHT, patients with OPC and oral cancer patients as compared with the NHT group. This was also the case for urinary thioether levels. Levels of urinary nicotine and cotinine were also higher in the non-abstinence group with oral cancers. CONCLUSION: The results confirmed that tobacco chewing and smoking habits are prominent risk factors for development of oral cancer in the western part of India (Gujarat). Urinary nicotine, cotinine, NO2+NO3 and thioether levels can be helpful for screening programs for oral cancer.

A review of proteomics in cancer research.

The most functional compartment encoded by the genome is proteome. Therefore study of proteome i.e. proteomics is the promising approach in identification, separation and quantitation of functional changes. It aims to gain a comprehensive understanding of the expressions, modifications, interactions, and regulation of proteins in cells. The power of two-dimensional electrophoresis and advances in mass spectrometric techniques, combined with sequence data base correlation, has enabled speed and accuracy in identification of proteins in complex mixtures. Therefore, proteomics may provide a better understanding of the molecular basis of cancer growth, with identification of potential pathological markers and therapeutic targets. Tobacco related cancers are the major health hazard in Asian countries; the proteomics approach should be employed for understanding the underlying disease processes and hopefully reveal important clues for identifying high risk individuals and early changes during malignant transformation.