• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4319-4322
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• 2016

Background: FLT3 is mutated in about 1/3 of acute myelogenous leukemia (AML) patients. The aim of the present study was to report the prevalence of FLT3 mutations and comparison with prognostic factors in AML patients in the Northeastern of Iran. Materials and Methods: This cross-sectional study concerned 100 AML cases diagnosed based on bone marrow aspiration and peripheral blood. DNA for every AML patient was extracted and underwent PCR with FLT3-ITD primers. Results: The mean age at diagnosis was 28.5 years (range, 1-66 years), 52 patients (52%) being male. Out of 100 AML patients, 21 (21%) had FLT3 mutation, (17 with FLT3-ITD, 81%, and 4 with FLT3-D825, 19%). Of the 21, 14 (66.7%) had heterozygous mutation. There was no significant difference between age, sex and organomegaly between patients with FLT3 mutation versus FLT3 wild-type. Conclusions: Our frequency of FLT3 is in line with earlier fidnings of approximately 20 to 30% and also the prevalence of FLT3-ITD is more than FLT3-D35 mutation. There was no significant difference between prognostic factors (age and sex) in the patients with FLT3 mutation versus FLT3 wild-type. The prevalence of FLT3 heterozygous mutations is more that homozygous mutations in AML patients.

• Asian Pacific Journal of Cancer Prevention
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• 제16권12호
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• pp.4869-4872
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• 2015

Background: Mutations of the FMS-like tyrosine kinase-3 (FLT3) receptor gene may promote proliferation via activation of multiple signaling pathways. FLT3-internal tandem duplication (FLT3-ITD) is the most common gene alteration found in patients diagnosed with acute myeloid leukaemia (AML) and has been associated with poor prognosis. Materials and Methods: We performed mutational analysis of exons 14-15 and 20 of the FLT3 gene in 54 AML patients using PCR-CSGE (conformational sensitive gel electrophoresis) followed by sequencing analysis to characterise FLT3 mutations in adult patients diagnosed with AML at Hospital USM, Kelantan, Northeast Peninsular Malaysia. Results: FLT3 exon 14-15 mutations were identified in 7 of 54 patients (13%) whereas no mutation was found in FLT3 exon 20. Six ITDs and one non-ITD mutation were found in exon 14 of the juxtamembrane (JM) domain of FLT3. FLT3-ITD mutations were associated with a significantly higher blast percentage (p-value = 0.008) and white blood cell count (p-value = 0.023) but there was no significant difference in median overall survival time for FLT3-ITD+/FLT3-ITD- within 2 years (p-value = 0.374). Conclusions: The incidence of FLT3-ITD in AML patients in this particular region of Malaysia is low compared to the Western world and has a significant association with WBC and blast percentage.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4395-4399
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• 2016

The FLT3-ITD mutation is one of the most frequent genetic abnormalities in acute myeloid leukemia (AML) where it is associated with a poor prognosis. The FLT3-ITD mutation could, therefore, be a potential molecular prognostic marker important for risk-stratified treatment options. We amplified the FLT3 gene at exon 14 and 15 in 52 AML patients (aged between 2 months and 74 years) from 4 referral centers (a university hospital and 3 regional hospitals in Northeast Thailand), using a simple PCR method. FLT3-ITD mutations were found in 10 patients (19.2%), being more common in adults than in children (21.1% vs. 14.3%) and more prevalent in patients with acute promyelocytic leukemia (AML-M3) than AML-non M3 (4 of 10 AML-M3 vs. 6 of 42 AML-non M3 patients). Duplication sequences varied in size-between 27 and 171 nucleotides (median=63.5) and in their location. FLT3-ITD mutations with common duplication sequences accounted for a significant percentage in AML patients in northeastern Thailand. This simple PCR method is feasible for routine laboratory practice and these data could help tailor use of the national protocol for AML.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4581-4585
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• 2012

Fms-like tyrosine kinase 3 (FLT3) performs a vital role in the pathogenesis of hematopoietic malignancies. Therefore in recent times, the focus of several studies was on use of FLT3 as a prognostic marker. The present study investigated the molecular characterization and incidence of FLT3 mutations in acute leukemia patients in Pakistan. A total of 55 patients were studied, of which 25 were suffering from acute lymphoblastic leukemia (ALL) and 30 were suffering from acute myeloid leukemia (AML). The polymerase chain reaction demonstrated FLT3/ITD mutations in 1 (4%) of 25 ALL patients, a male with the L2 subtype. In AML cases the rate was 4 (13.3%) of 30, three males and one female. The AML-M4 subtype was found in three and the AML M2 subtype in the other. In the AML cases, a statistically significant (p=0.009) relationship was found between WBC (109/L) and FLT3/ITD positivity. However, no significant relationship was found with other clinical parameters (p>0.05). In acute myeloid leukemia (AML) $FLT3/ITD^+$ mutation was more prevalent in elderly patients 31-40 age groups, 21-30 and 51-60 age groups respectively. In acute lymphoblastic leukemia (ALL) statistically no significant relationship was found between clinical features and FLT3/ITD positivity (p>0.05). However, in acute lymphoblastic leukemia (ALL) $FLT3/ITD^+$ mutation was more commonly found in age groups of 21-30.

• Genomics & Informatics
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• 제11권1호
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• pp.34-37
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• 2013

This study evaluated the effects of somatic mutations and single nucleotide polymorphisms (SNPs) on disease progression and tried to verify the two-hit theory in cancer pathogenesis. To address this issue, SNP analysis was performed using the UCSC hg19 program in 10 acute myeloid leukemia patients (samples, G1 to G10), and somatic mutations were identified in the same tumor sample using SomaticSniper and VarScan2. SNPs in KRAS were detected in 4 out of 10 different individuals, and those of DNMT3A were detected in 5 of the same patient cohort. In 2 patients, both KRAS and DNMT3A were detected simultaneously. A somatic mutation in IDH2 was detected in these 2 patients. One of the patients had an additional mutation in FLT3, while the other patient had an NPM1 mutation. The patient with an FLT3 mutation relapsed shortly after attaining remission, while the other patient with the NPM1 mutation did not suffer a relapse. Our results indicate that SNPs with additional somatic mutations affect the prognosis of AML.

• Laboratory Medicine Online
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• 제7권1호
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• pp.13-19
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• 2017

배경: 저자들은 FLT3-ITD (fms-like tyrosine kinase-internal tandem duplication) 돌연변이의 정량 및 반복 염기 길이를 동시에 측정하는 정량 절편 분석법(fragment analysis)의 민감도를 평가하고, 분석적 성능을 검증하였다. 방법: FLT3-ITD 돌연변이의 정량과 수는 절편분석법으로 측정하였다. 변이 대립유전자와 정상 대립유전자를 혼합한 계대희석 표준물질로 절편 분석법, 일반 PCR법, 염기서열분석법의 FLT3-ITD 변이 검출한계를 측정하였다. 정상 공여자 50검체를 이용하여 특이도를 평가하였다. 급성골수성백혈병 환자의 481검체에 대하여 절편 분석법과 일반 PCR법으로 검사를 시행하고 그 결과를 비교 분석하였다. 결과: 절편 분석법의 돌연변이 최소 검출 농도는 5%였으며, 일반 PCR 검사법과 직접염기서열분석법은 각각 10%, 20%의 결과를 보였다. 급성골수성백혈병 환자의 481 검체를 분석한 결과, FLT3-ITD는 40.1% (193/481)에서 양성이었다. 변이 대립유전자의 정량값은 1.7-94.1% (중앙값 28.2%)로 다양하였으며, 반복 염기의 길이의 범위는 14bp-153 bp (중앙값 49bp)였다. 일반 PCR 검사법과 비교한 결과 방법간 일치도는 97.7% (470/481)였다. 절편 분석법이 일반 PCR 검사법에 비해 더 높은 민감도를 보였고, 11건의 돌연변이가 더 검출되었다. 이 중 7검체는 변이 대립유전자의 양이 10% 미만으로 일반 PCR 검사에서 검출되지 않았다(3.3-9.5%). 또 다른 불일치 세 검체에서는 PCR inhibitor의 영향으로 일반 PCR 방법에서 위음성 결과를 보였으며, 다른 한 검체는 돌연변이 중복 길이가 14 bp로 매우 짧아 일반 PCR에서 정상 밴드와 구별되지 않는 경우였다. 결론: 본 연구에서 저자들이 사용한 절편 분석법은 FLT3-ITD 돌연변이의 정량값과 중복된 길이를 동시에 측정할 수 있는 검사법으로, 민감하고 정확하여 급성골수성백혈병 환자에서 FLT3-ITD의 진단 및 추적 검사에 유용할 것으로 기대된다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권3호
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• pp.1247-1253
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• 2014

Mutations in the DNMT3A and IDH genes represent the most common genetic alteration after FLT3/NPM1 in acute myeloid leukemia (AML). We here analyzed the frequency and distribution pattern of DNMT3A and IDH mutations and their associations with other molecular markers in normal karyotype AML patients. Fortyfive patients were screened for mutations in DNMT3A (R882), IDH1 (R132) and IDH2 (R140 and R172) genes by direct sequencing. Of the 45 patients screened, DNMT3A and IDH mutations were observed in 6 (13.3%) and 7 (15.4%), respectively. Patients with isolated DNMT3A mutations were seen in 4 cases (9%), isolated IDH mutations in 5 (11.1%), while interestingly, two cases showed both DNMT3A and IDH mutations (4.3%). Nucleotide sequencing of DNMT3A revealed missense mutations (R882H and R882C), while that of IDH revealed R172K, R140Q, R132H and R132S. Both DNMT3A and IDH mutations were observed only in adults, with a higher frequency in males. DNMT3A and IDH mutations were significantly associated with NPM1, while trends towards higher coexistence with FLT3 mutations were observed. This is the first study to evaluate DNMT3A/IDH mutations in Indian patients. Significant associations among the various molecular markers was observed, that highlights cooperation between them and possible roles in improved risk stratification.

• BLOOD RESEARCH
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• 제53권4호
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• pp.294-298
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• 2018

Background Production of immunosuppressive enzymes such as indoleamine 2,3-dioxygenase (IDO) is one of the strategies employed by hematologic malignancies, including acute myeloid leukemia (AML), to circumvent immune surveillance. Moreover, IDO has the ability to convert $CD4^+CD25^-$ conventional T cells into regulatory T cells (Tregs). In this study, we evaluated the expression of IDO in cytogenetically normal acute myeloid leukemia (CN-AML) patients and its correlation with the Treg marker, FOXP3, as well as clinical and laboratory parameters. Methods Thirty-seven newly diagnosed CN-AML patients were enrolled in our study along with 22 healthy individuals. The expression of the IDO and FOXP3 genes was analyzed by SYBR Green real-time PCR. Results Both IDO and FOXP3 were highly upregulated in CN-AML patients compared to control groups (P=0.004 and P=0.031, respectively). A positive correlation was observed between IDO and FOXP3 expression among AML patients (r=0.512, P=0.001). Expression of IDO and FOXP3 showed no significant correlation with laboratory parameters such as white blood cell and platelet counts, hemoglobin levels, bone marrow blast percentage, gender, and FLT3 mutation status (P>0.05). Conclusion Higher IDO expression in CN-AML patients may be associated with an increased Treg phenotype which may promote disease progression and lead to poor prognosis of CN-AML patients.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.895-898
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• 2014

Objectives: The present study aimed to examine the cytogenetic and genetic mutation features of acute myeloid leukemia (AML) in elderly Chinese patients. Methods: A retrospective analysis of cytogenetics and genetic mutations was performed in 113 cases (age range 50-82 years) with de novo AML. Results: The most frequent cytogenetic abnormality was t (15;17) (q22;q21), detected in 10.0% (n = 9) of successfully analyzed cases, followed by t (8;21) (q22;q22) in 8.89% (n = 8), and complex karyotypes in 5.56% (n = 5). Those with complex karyotypes included 4 cases (4.44%) of monosomal karyotypes. The frequencies of NPM1, FLT3-ITD, c-kit, and CEBPA mutations were 27.4% (31/113), 14.5% (16/110), 5.88% (6/102), and 23.3% (7/30), respectively. The complete remission rates of patients in low, intermediate, and high risk groups were 37.5%, 48.6%, and 33.3%, respectively (${\chi}^2$ = 0.704, P = 0.703) based on risk stratification. Conclusion: Cytogenetics and genetic mutations alone may not be sufficient to evaluate the prognoses of elderly AML patients. The search for a novel model that would enable a more comprehensive evaluation of this population is therefore imperative.