• Clinical and Experimental Pediatrics
• /
• v.56 no.6
• /
• pp.247-253
• /
• 2013

Purpose: In children with acute leukemia, bone marrow genetic abnormalities (GA) have prognostic significance, and may be the basis for minimal residual disease monitoring. Since April 2007, we have used a multiplex reverse transcriptase-polymerase chain reaction tool (HemaVision) to detect of GA. Methods: In this study, we reviewed the results of HemaVision screening in 270 children with acute leukemia, newly diagnosed at The Catholic University of Korea from April 2007 to December 2011, and compared the results with those of fluorescence in situ hybridization (FISH), and G-band karyotyping. Results: Among the 270 children (153 males, 117 females), 187 acute lymphoblastic leukemia and 74 acute myeloid leukemia patients were identified. Overall, GA was detected in 230 patients (85.2%). HemaVision, FISH, and G-band karyotyping identified GA in 125 (46.3%), 126 (46.7%), and 215 patients (79.6%), respectively. TEL-AML1 (20.9%, 39/187) and AML1-ETO (27%, 20/74) were the most common GA in ALL and AML, respectively. Overall sensitivity of HemaVision was 98.4%, with false-negative results in 2 instances: 1 each for TEL-AML1 and MLL-AF4. An aggregate of diseases-specific FISH showed 100% sensitivity in detection of GA covered by HemaVision for actual probes utilized. G-band karyotype revealed GA other than those covered by HemaVison screening in 133 patients (49.3%). Except for hyperdiplody and hypodiploidy, recurrent GA as defined by the World Health Organizationthat were not screened by HemaVision, were absent in the karyotype. Conclusion: HemaVision, supported by an aggregate of FISH tests for important translocations, may allow for accurate diagnosis of GA in Korean children with acute leukemia.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.4
• /
• pp.1603-1609
• /
• 2014

Background: The response to treatment and overall survival (OS) of patients with acute myeloid leukemia (AML) is variable, with a median ranging from 6 months to 11.5 years. TP53 is associated with old age, chemotherapy resistance, and worse OS. Using genetic sequencing, we set out to look at our own experience with AML, and hypothesized that both TP53 mutations and SNPs at codon 72 would mimic the literature by occurring in a minority of patients, and conferring a worse OS. Materials and Methods: We performed a pilot study of randomly selected, newly diagnosed AML patients at Mount Sinai Medical Center, diagnosed from 2005-2008 (n=10). TP53 PCR sequencing was performed using DNA from bone marrow smears. Analysis was accomplished using Mutation Surveyor software with confirmation of the variants using the COSMIC and dbSNP databases. Results: Fewer than half of the patients harbored TP53 mutations (40%). There was no significant difference in OS based on gender, AML history, risk-stratified karyotype, or TP53 mutation. There were possible trends toward improved survival among patients less than 60 (11 vs 4 months, p=0.09), Hispanics (8 vs 1 months, p=0.11), and those not harboring SNP P72R (8 vs 2 months, p=0.10). There was a significant improvement in survival among patients with better performance status (28 vs 4 months, p=0.01) and those who did not have a complex karyotype (8 vs 1 months, p=0.03). The most commonly observed TP53 mutation was a missense N310K (40%) and the most commonly observed SNP was P72R (100.0%). Conclusions: Our study confirms previous reports that poor PS and the presence of a complex karyotype are associated with a decreased OS. In our cohort, TP53 mutations were relatively common, occurring more frequently in male patients with an adverse karyotype. Although there was no significant difference in survival between TP53 mutated and un-mutated patients, there was a possible trend toward worse OS among patients with SNP P72R. Larger studies are needed to validate these findings.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.1
• /
• pp.431-437
• /
• 2016

In this investigation, global DNA methylation patterns and the specific methylation status of 5 genes were studied in DNA from peripheral blood (PB) and impact on progression free survival (PFS) and overall-survival (OS) in patients with de novo or relapsed acute myeloid leukemia (AML) treated with decitabine-based regimens waas assessed. DNA was isolated from PB samples at the time of -1, 1, and 7 days of chemotherapy. Global methylation was determined by ELISA, and the CpG island DNA methylation profile of 5 genes using a DNA methylation PCR system. Our data demonstrated that patients with a high level of 5-mC had a poor prognosis after demethylation therapy and those who have low levels of 5-mC in PB achieved higher CR and better SO, but there was no significant correlation found between the 5-mC levels and other clinical features before treatment except the disease status. Higher methylation status of Sox2 and Oct4 genes was associated with differential response to demethylation therapy. A relatively low methylation percentage in one or both of these two genes was also associated with longer OS after decitabine based chemotherapy. We also suggest that global DNA and Oct-4/Sox2 methylation might impact on the pathogenesis of leukemia and play an important role in the initiation and progression. Moreover, dynamic analysis of 5-mC and Oct-4/Sox2 in peripheral blood nucleated cells of leukemia patients may provide clues to important molecular diagnostic and prognostic targets.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.4
• /
• pp.1719-1723
• /
• 2014

Background: The current study was aimed to elucidate the association of thymidylate synthase (TYMS) 5'-UTR 28bp tandem repeat and cytosolic serine hydroxymethyltransferase (cSHMT) C1420T polymorphisms with acute leukemia in South Indian subjects. A total of 812 subjects [523 healthy controls, 148 acute lymphoblastic leukemia (ALL) cases and 141 acute myeloid leukemia (AML) cases] were screened for TYMS 5'-UTR 28bp tandem repeat and cSHMT C1420T using PCR-AFLP and PCR-with confronting two-pair primers (CTPP) approaches. TYMS 5'-UTR 2R allele frequencies of controls, ALL and AML cases were 35.3%, 28.0% and 30.1% respectively. This polymorphism conferred protection against ALL (OR: 0.71, 95%CI: 0.53-0.96) while showing no statistically significant association with AML (OR: 0.79, 95%CI: 0.58, 1.07). The cSHMT variant allele (T-) frequencies of ALL and AML cases (6.42% and 5.68% respectively) were significantly lower compared to controls (58.3%). This polymorphism conferred protection against ALL (OR: 0.049, 95%CI: 0.029-0.081) and AML (OR: 0.043, 95%CI: 0.025-0.074). The TYMS 5'-UTR 2R2R genotype was associated with a lower total leukocyte count, smaller percentage of blasts, and more adequate platelet count compared to 2R3R and 3R3R genotypes in ALL cases. No such genotype-dependent differences were observed in AML cases. ALL cases carrying the cSHMT C1420T polymorphism showed higher disease free survival compared to those with the wild genotype. To conclude, the TYMS 5'-UTR 28bp tandem repeat reduces risk for ALL while cSHMT C1420T reduces risk for both ALL and AML. Both also influence disease progression in ALL.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.2
• /
• pp.629-635
• /
• 2014

Background: Acute myeloid leukemia (AML) is a fatal hematological malignancy which is resistant to a variety of chemotherapy drugs. Myeloid cell leukemia-1 (Mcl-1), a death-inhibiting protein that regulates apoptosis, has been shown to be overexpressed in numerous malignancies. In addition, it has been demonstrated that the expression level of the Mcl-1 gene increases at the time of leukemic relapse following chemotherapy. The aim of this study was to target Mcl-1 by small interference RNA (siRNA) and analyze its effects on survival and chemosensitivity of acute myeloid leukemia cell line HL-60. Materials and Methods: siRNA transfection was performed with a liposome approach. The expression levels of mRNA and protein were measured by real-time quantitative PCR and Western blot analysis, respectively. Trypan blue assays were performed to evaluate tumor cell growth after siRNA transfection. The cytotoxic effects of Mcl-1 siRNA (siMcl-1) and etoposide were determined using MTT assay on their own and in combination. Apoptosis was quantified using a DNA-histone ELISA assay. Results: Transfection with siMcl-1 significantly suppressed the expression of Mcl-1 mRNA and protein in a time-dependent manner, resulting in strong growth inhibition and spontaneous apoptosis. Surprisingly, pretreatment with siMcl-1 synergistically enhanced the cytotoxic effect of etoposide. Furthermore, Mcl-1 down-regulation significantly increased apoptosis sensitivity to etoposide. No significant biological effects were observed with negative control siRNA treatment. Conclusions: Our results suggest that specific suppression of Mcl-1 by siRNA can effectively induce apoptosis and overcome chemoresistance of leukemic cells. Therefore, siMcl-1 may be a potent adjuvant in leukemia chemotherapy.

• Molecules and Cells
• /
• v.43 no.2
• /
• pp.145-152
• /
• 2020

RUNX1 plays an important role in the regulation of normal hematopoiesis. RUNX1 mutations are frequently found and have been intensively studied in hematological malignancies. Germline mutations in RUNX1 cause familial platelet disorder with predisposition to acute myeloid leukemia (FPD/AML). Somatic mutations of RUNX1 are observed in various types of hematological malignancies, such as AML, acute lymphoblastic leukemia (ALL), myelodysplastic syndromes (MDS), myeloproliferative neoplasm (MPN), chronic myelomonocytic leukemia (CMML), and congenital bone marrow failure (CBMF). Here, we systematically review the clinical and molecular characteristics of RUNX1 mutations, the mechanisms of pathogenesis caused by RUNX1 mutations, and potential therapeutic strategies to target RUNX1-mutated cases of hematological malignancies.

• Molecules and Cells
• /
• v.39 no.4
• /
• pp.330-336
• /
• 2016

Long non-coding RNAs (lncRNAs) are involved in multiple cellular events, as well as in tumorigenesis. Colon cance-rassociated transcript-1 (CCAT1) gene encodes an lncRNA whose over-activation was observed in an expanding list of primary human solid tumors and tumor cell lines, however its biological roles in acute myeloid leukaemia (AML) has not been reported yet at present. In this study, the aberrant upregulation of CCAT1 was detected in French-American-British M4 and M5 subtypes of adult AML patients. By gain- and loss-of-function analysis, we determined that CCAT1 repressed monocytic differentiation and promoted cell growth of HL-60 by sequestering tumor suppressive miR-155. Accordingly, a significant decrease in miR-155 level was detected in AML patients. Reintroduction of miR-155 into HL-60 cells restored monocytic maturation and repressed cell proliferation. Furthermore, CCAT1 could up-regulated c-Myc via its competing endogenous RNA (ceRNA) activity on miR-155. In conclusion, these results revealed new mechanism of lncRNA CCAT1 in AML development, and suggested that the manipulation of CCAT1 expression could serve as a potential strategy in AML therapy.

• Molecules and Cells
• /
• v.41 no.5
• /
• pp.444-453
• /
• 2018

Aberrations in histone modifications are being studied in mixed-lineage leukemia (MLL)-AF9-driven acute myeloid leukemia (AML). In this study, we focused on the regulation of the differentiation of the MLL-AF9 type AML cell line THP-1. We observed that, upon phorbol 12-myristate 13-acetate (PMA) treatment, THP-1 cells differentiated into monocytes by down-regulating Aurora kinase A (AURKA), resulting in a reduction in H3S10 phosphorylation. We revealed that the AURKA inhibitor alisertib accelerates the expression of the H3K27 demethylase KDM6B, thereby dissociating AURKA and YY1 from the KDM6B promoter region. Using Flow cytometry, we found that alisertib induces THP-1 differentiation into monocytes. Furthermore, we found that treatment with the KDM6B inhibitor GSK-J4 perturbed the PMA-mediated differentiation of THP-1 cells. Thus, we discovered the mechanism of AURKA-KDM6B signaling that controls the differentiation of THP-1 cells, which has implications for biotherapy for leukemia.

• Biomedical Science Letters
• /
• v.24 no.4
• /
• pp.426-429
• /
• 2018

Chronic eosinophilic leukemia (CEL) is characterized by eosinophilia and organ damage. Imatinib is widely used for treating CEL, chronic myeloid leukemia (CML) and acute myeloid leukemia (AML). Unfortunately, the cancer cells gain resistance against the drug after prolonged molecular-targeted therapies. Imatinib-resistant EoL-1 (EoL-1-IR) cells were produced from chronic eosinophilic leukemia cells (EoL-1) after treatment with imatinib for a long duration. Two-dimensional electrophoresis (2-DE) analysis revealed numerous protein variations in the EoL-1 and EoL-1-IR sub-types. Compared to the EoL-1 cells, expression levels of TIP49, RBBP7, ${\alpha}$-enolase, adenosine deaminase, C protein, galactokinase, eukaryotic translation initiation factor, $IFN-{\gamma}$, and human protein homologous to DROER were increased, whereas core I protein, proteasome subunit p42, heterogeneous ribonuclear particle protein, chain B, and nucleoside diphosphate were decreased in the EoL-1-IR cells. Taken together, these results contribute to understanding the pathogenic mechanism of drug-resistant diseases.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.3
• /
• pp.1247-1253
• /
• 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.