Niyaz A Azad

Impact of molecular alterations of BRAF in the pathogenesis of thyroid cancer.

BRAF alterations represent a novel indicator of the progression and aggressiveness of thyroid carcinogenesis. So, the main aim of the study was to elucidate the involvement of BRAF gene mutations and its expression in Kashmiri (North India) patients and investigate their association with clinico-pathological characteristics. Mutational analysis of BRAF gene was performed by polymerase chain reaction followed by DNA sequencing, whereas analysis of BRAF protein expression was done by western blotting. Overall mutations in BRAF was found to be 25% (15 of 60) and all of them were transversions (T>A) affecting codon 600 (valine to glutamine), restricted only to papillary thyroid cancer and well-differentiated grade. Patients with well-differentiated disease and in particular elevated thyroid-stimulating hormone levels were significantly associated with BRAF mutations (P < 0.05). Overall, 90% (54 of 60) of thyroid cancer cases showed increased expression of BRAF and non-smokers being significantly associated with BRAF over-expression. Totally, 86.7% (13 of 15) of BRAF mutation-positive patients were having over-expression of BRAF protein, whereas 91.2% (41 of 45) of patients with wild-type BRAF status were having over-expressed BRAF protein (P > 0.05). We conclude that both mutational events as well as over-expression of BRAF gene is highly implicated in pathogenesis of thyroid cancer and the BRAF protein over-expression is independent of the BRAF mutational status of thyroid cancer patients.

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.

Phytohemagglutinin-Induced Peripheral Blood Cytogenetics: A Valid Means for Diagnosis and Imatinib Therapy Monitoring of Chronic Phase Chronic Myeloid Leukemia Patients

Background: Conventional cytogenetic studies have been viewed as the standard follow-up method for Chronic Myeloid Leukemia patients on Imatinib. However, this approach is beset with high probability of poor metaphase index. In this study, we evaluated the application of Phytohemagglutinin (PHA)-induced peripheral blood culture based cytogenetic analysis (Karyotyping) in diagnosis and Imatinib treatment monitoring of the Chronic Phase CML patients. Methods: The patient samples were subjected to the PHA-induced peripheral blood culture based cytogenetic technique (Karyotyping) to establish their baseline cytogenetic status followed by their follow up Karyotyping twice at the end of 3 and 6 months of treatment. The simultaneous quantitative PCR (q-PCR) assay for BCR-ABL fusion gene transcript on the samples corresponding to their baseline as well as the follow up cytogenetic status was also carried out to authenticate the cytogenetic findings. Results: Complete Cytogenetic Response (CCR) and Partial Cytogenetic Response (PCR) was initially observed in 09 (30%) and 16 (53.3%) respectively of 30 CML patients with 05 (16.6%) patients showing no such response at the end of 3 months. At 6 months, 25 (83.3%) and 02 (6.6%) showed CCR and PCR respectively with 03 (10%) of patients without any response. The findings completely correlated with the hematological response, the q-PCR assay as well as the overall disease condition observed in the patients. Conclusion: As acquiring bone-marrow sample involves morbid consequences for patients and metaphases yielded thereby are difficult to analyze, PHA-induced peripheral blood Karyotyping was explored as an alternative. It was found to have significant potential in serving as a valid tool in the diagnosis and assessment of follow up response to Imatinib mesylate treatment of patients with chronic phase CML.

p15ink4b Loss of Expression by Promoter Hypermethylation Adds to Leukemogenesis and Confers a Poor Prognosis in Acute Promyelocytic Leukemia Patients.

Purpose The p15Ink4b gene exerts its influence as an inhibitor of cyclin-dependent kinases and is frequently associated with hematological malignancies. Inactivation of this gene through DNA methylation has been found to be the most prevalent epigenetic alteration reported, with a high frequency in all French-American-British subtypes of acute myeloid leukemias, including acute promyelocytic leukemia (APL). In this study,we investigated the prognostic significance of p15 gene promoter hypermethylation and its expression in APL patients of Kashmir (North India). Materials and Methods p15 gene promoter hypermethylation was conducted by methylation-specific polymerase chain reaction, while its subsequent expression analysiswas carried out by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Results Of the 37 patients, 16 (43.2%) were found to have methylated p15 genes. Of these 16 cases, seven (43.8%) were methylated partially and nine (56.2%) were found to have complete methylation. Moreover, nine of the 37 patients (24.3%) who presented with leukocytosis at their baseline had complete p15 gene methylation as well (p < 0.05). Semiquantitative RT-PCR showed a complete loss of p15 expression in nine patients with complete methylation coupled with leukocytosis (p=0.031), while seven patients with partial methylation showed decreased p15 expression. Six patients relapsed during the maintenance phase of treatment and were found to have a completely methylated p15 gene and no p15 mRNA. Conclusion Complete methylation and loss of p15 gene expression causes susceptibility to relapse and decreased survival in APL patients. Thus, p15 promoter hypermethylation is a prospective prognostic indicator and a reliable clinical aid in assessment of patients with APL.

Identification of Unique Pattern of CFTR Gene Mutations in Cystic Fibrosis in an Ethnic Kashmiri Population (North India)

Background: Cystic Fibrosis (CF) one of the most common severe autosomal recessive disorders is caused by mutations in CFTR gene. The mutation distributions vary widely between different geographical and ethnic groups. In view of ethnic nature of Kashmiri population (North India), we aim at looking for the 3 common mutations Δ508, 3849+10 kb, C>T and W1282X in CF suspected cases. Method: The mutations were evaluated in 150 highly suspected children with CF, proven by clinical features. ARMS-PCR was used for mutation detection of Δ508 and W1282X while as 3849+10 kb, C>T was assessed by indigenously developed ARMS-PCR and results were confirmed by RFLP. Results: Of the 150 suspected CF cases, one of the three mutations was found in 60 out of the 300 alleles genotyped. Δ508 mutation was found in 36 of 150 (24%) cases, 3849+10 kb, C>T in 24 of 150(16%) cases while as no mutation was observed in W1282X. Interestingly 08 of 09 samples with normal sweat chloride were detected positive for 3849+10 kb, C>T mutation. Conclusion: In this report, frequency of the Δ508 mutation in Kashmiri children with CF is less as compared to the Western Countries. Interestingly, we identified 3849+10 kb, C>T mutation as unique in population under study with much higher frequency as compared to rest of the world. Further we found intron 19, 3849+10 kb, C>T mutation serves as marker in those CF cases having sweat chloride negative.

Molecular and Cytogenetic Evaluation of Gender in Patients Born with Ambiguous Genitalia from Different Regions of the Valley of Kashmir,North India

Ambiguous Genitalia, a rare genetic disorder is caused by defects in the process of fetal sexual determination and differentiation where a newborn needs prompt evaluation to detect lethal conditions and gender assignment. This genetic screening is taken up with an aim to evaluate the prevalence of the patients born with Ambiguous Genitalia existing in our population. We evaluated the patients for Ambiguous Genitalia with Polymerase Chain Reaction (PCR) using SRY gene and cytogenetic analysis for detecting X and Y chromosome was performed by conventional Karyotyping. Of the 50 Ambiguous Genitalia cases, 21 (42.0 %) were detected positive for SRY gene with 46, XY Karyotype and were recognized as males while as rest of cases 29 of 50 (58%) were confirmed as females by negative SRY gene coupled with 46, XX Karyotype. All the 21 cases positive for SRY gene were cytogenetically evaluated with 46, XY except two cases, one of testicular feminization syndrome and another case of AIS where a Karyotype revealed 46, XY but were negative for SRY gene. 09 of the 50 cases (18%) had undetermined sex and among these 05 (55.5%) were found to be negative for SRY gene with 46, XX Karyotype except one case with 47, XX which was an Edward’s syndrome. 04 of the 09 cases (45.5%) were detected as males with positive SRY gene. Overall 04 cases (08.0 %) that were socially recognized as female for two decades were confirmed to be carrying Y chromosome as depicted by positive SRY gene with 46, XY Karyotype. We found that newborn with Ambiguous Genitalia exist in our region in a good number and the cytogenetic method coupled with molecular analysis by PCR are essential to unfold the sex and help in proper assignment of gender in intersex disorders.

Real-time quantitative PCR: a reliable molecular diagnostic and follow-up tool for 'Minimal Residual Disease' assessment in Chronic Myeloid Leukemia.

Molecular monitoring of BCR-ABL transcript levels by real-time quantitative PCR is increasingly being used to diagnose the disease and assess treatment response in patients with chronic myeloid leukemia (CML). This has become particularly relevant when residual levels of leukemia usually fall below the level of detection by cytogenetic analysis. Forty-two CML patients, including 18 males (42.86%) and 24 females (57.14%) aged 7–75 years, were enlisted for the study and followed-up for the response to imatinib treatment. Patients were subjected to Multiplex RT-PCR (reverse-transcriptase PCR) and were all found to harbor either e13a2 or the e14a2, which could be analyzed by a single Taqman probe based quantitation kit (Geno-Sen’s) to quantitate the BCR-ABL transcript load. The Multiplex RT-PCR and peripheral blood cytogenetics providing specific and sensitive detection of BCR-ABL fusion transcripts and metaphase signal load respectively were used as parallel reference tools to authenticate the q-PCR findings. There was 100% concordance between the multiplex RT-PCR and the q-PCR as every positive RT-PCR assay for a transcript reflected as q-PCR load of above 0% for that transcript. q-PCR also demonstrated a strong Pearson correlation with the cytogenetic response.

Prognostic Implication of BCR-ABL Fusion Transcript Variants in Chronic Myeloid Leukemia (CML) Treated with Imatinib. A First of Its Kind Study on CML Patients of Kashmir

Background: The prognostic significance of the common BCR-ABL transcripts like e13a2 (b2a2) and e14a2 (b3a2) in Chronic myeloid leukemia (CML) has been reported from patients treated with different tyrosine kinase inhibitors but its impact on clinical response and overall survival remains still unexplored. The aim of this study was to evaluate the prognostic significance of different transcript types in a cohort of CML patients treated with imatinib. Methods: A total 42 confirmed cases of Chronic Myeloid Leukemia (CML) patients were recruited into our cohort study and a multiplex Reverse Transcriptase-Polymerase Chain Reaction technique (RT-PCR) was used to detect 3 main transcript types ‘e1a2’, ‘e13a2’, and ‘e14a2’ found in CML. Results: Only two types of transcripts e13a2 (b2a2) and e14a2 (b3a2) were detected in our CML patients and none had the e1a2 type. All the patients were RT-PCR positive for either e13a2 or e14a2 fusion transcript demonstrating 100% concordance with their Ph+ve cytogenetic status at baseline. TLC count (range of 201-600x103/µl) and platelet count (range of 201-900x103/µl) at baseline were found to be associated more with the e14a2 (b3a2) than the e13a2 (b2a2) transcript type (p-value: 0.001). The two transcripts found did not relate significantly towards sex, age-group or indicated spleen size ranges as well as percentage ranges of blast cells. Conclusion: We conclude that there is no overall prognostic implication of either the e13a2 or the e14a2 transcript type across the spectrum of indicated clinical parameters evaluated. Even the overall survival analysis of the two transcript types revealed no prognostic association whatsoever.

PHA-Induced Peripheral Blood Cytogenetics and Molecular Analysis: a Valid Diagnostic and Follow-up Modality for Acute Promyelocytic Leukemia Patients Treated with ATRA and/or Arsenic Tri-oxide.

BACKGROUND Acute promyelocytic leukemia (APML) is characterized by the reciprocal translocation t(15;17) (q22;q12) resulting in the PML-RARα fusion gene. A dual diagnostic and follow up approach was applied including cytogenetic demonstration of the t(15;17) translocation and detection of PML-RARα chimeric transcripts by molecular means. PURPOSE Conventional cytogenetics involving bone marrow is beset with high probability of poor metaphase index and was substituted with phytohemagglutinin (PHA)-induced peripheral blood culture based cytogenetic analysis as a diagnostic and follow up modality in APML patients of Kashmir (North India). Both qualitative (RT-PCR) and quantitative (Q-PCR) tests were simultaneously carried out to authenticate the modified cytogenetics. MATERIALS AND METHODS Patient samples were subjected to the said techniques to establish their baseline as well as follow-up status. RESULTS Initial cytogenetics revealed 30 patients (81%) positive for t(15;17) whereas 7 (19%) had either cryptic translocation or were negative for t(15;17). Two cases had chromosome 16q deletion and no hallmark translocation t(15;17). Q-PCR status for PML-RARα was found to be positive for all patients. All the APML patients were reassessed at the end of consolidation phase and during maintenance phase of chemotherapy where 6 patients had molecular relapse, wherein 4 also demonstrated cytogenetic relapse. CONCLUSIONS It was found that PHA-induced peripheral blood cytogenetics along with molecular analysis could prove a reliable modality in the diagnosis and assessment of follow up response of APML patients.