CML - Molecular Biology


Chronic myelogenous leukemia (CML) is characterised by the Philadelphia (Ph) chromosome which is seen in over 95% of patients. The Ph chromosome results from a reciprocal translocation between the long arms of chromosomes 9 and 22, this fuses the ABL1 from chromosome 9 to the BCR gene on chromosome 22. The median age of patients with Ph+ CML is 67 years of age, it can occasionally occur in children (2-3% of all childhood leukaemias).

See also: Chronic Myeloid Leukemia (CML) - clinical resources (24)

Literature Analysis

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Tag cloud generated 29 August, 2019 using data from PubMed, MeSH and CancerIndex

Mutated Genes and Abnormal Protein Expression (74)

How to use this data tableClicking on the Gene or Topic will take you to a separate more detailed page. Sort this list by clicking on a column heading e.g. 'Gene' or 'Topic'.

BCR 22q11.23 ALL, CML, PHL, BCR1, D22S11, D22S662 Translocation
-BCR-ABL Translocation in Chronic Myeloid Leukaemia
-BCR and Chronic Myelogenous Leukemia
CD34 1q32.2 -CD34 and Chronic Myelogenous Leukemia
ARHGEF1 19q13.2 LSC, GEF1, LBCL2, SUB1.5, P115-RHOGEF -ARHGEF1 and Chronic Myelogenous Leukemia
CD33 19q13.41 p67, SIGLEC3, SIGLEC-3 -CD33 and Chronic Myelogenous Leukemia
TET2 4q24 MDS, KIAA1546 -TET2 and Chronic Myelomonocytic Leukemia
CRKL 22q11.21 -CRKL and Chronic Myelogenous Leukemia
HOXA9 7p15.2 HOX1, ABD-B, HOX1G, HOX1.7 -HOXA9 and Chronic Myelogenous Leukemia
-t(7;11)(p15;p15) in Chronic Myelogenous Leukaemia
MECOM 3q26.2 EVI1, MDS1, KMT8E, PRDM3, RUSAT2, MDS1-EVI1, AML1-EVI-1 -MECOM and Chronic Myelogenous Leukemia
GALE 1p36.11 SDR1E1 -GALE and Chronic Myelogenous Leukemia
NUP98 11p15.4 ADIR2, NUP96, NUP196 -NUP98 and Chronic Myelogenous Leukemia
-t(7;11)(p15;p15) in Chronic Myelogenous Leukaemia
ASXL1 20q11.21 MDS, BOPS -ASXL1 and Chronic Myelogenous Leukemia
ELN 7q11.23 WS, WBS, SVAS -ELN and Chronic Myelogenous Leukemia
LYN 8q12.1 JTK8, p53Lyn, p56Lyn -LYN and Chronic Myelogenous Leukemia
GRB2 17q25.1 ASH, Grb3-3, MST084, NCKAP2, MSTP084, EGFRBP-GRB2 -GRB2 and Chronic Myelogenous Leukemia
JUNB 19p13.13 AP-1 -JUNB and Chronic Myelogenous Leukemia
PRAME 22q11.22 MAPE, OIP4, CT130, OIP-4 -PRAME and Chronic Myelogenous Leukemia
STAT5A 17q21.2 MGF, STAT5 -STAT5A and Chronic Myelogenous Leukemia
WARS 14q32.2 IFI53, IFP53, GAMMA-2 -WARS and Chronic Myelogenous Leukemia
MYB 6q23.3 efg, Cmyb, c-myb, c-myb_CDS -Genes, myb and Chronic Myelogenous Leukemia
ITCH 20q11.22 AIF4, AIP4, ADMFD, NAPP1 -ITCH and Chronic Myelogenous Leukemia
CD36 7q21.11 FAT, GP4, GP3B, GPIV, CHDS7, PASIV, SCARB3, BDPLT10 -CD36 and Chronic Myelogenous Leukemia
POU2F1 1q24.2 OCT1, OTF1, oct-1B -POU2F1 and Chronic Myelogenous Leukemia
G6PD Xq28 G6PD1 -G6PD and Chronic Myelogenous Leukemia
IRF8 16q24.1 ICSBP, IRF-8, ICSBP1, IMD32A, IMD32B, H-ICSBP -IRF8 and Chronic Myelogenous Leukemia
IL2RG Xq13.1 P64, CIDX, IMD4, CD132, SCIDX, IL-2RG, SCIDX1 -IL2RG and Chronic Myelogenous Leukemia
MDS1 3q26 PRDM3, MDS1-EVI1 -MDS1 and Chronic Myelogenous Leukemia
CD83 6p23 BL11, HB15 -CD83 and Chronic Myelogenous Leukemia
PCM1 8p22 PTC4, RET/PCM-1 -PCM1 and Chronic Myelogenous Leukemia
SALL4 20q13.2 DRRS, HSAL4, ZNF797 -SALL4 and Chronic Myelogenous Leukemia
SLCO1B3 12p12.2 LST3, HBLRR, LST-2, OATP8, OATP-8, OATP1B3, SLC21A8, LST-3TM13 -SLCO1B3 and Chronic Myelogenous Leukemia
U2AF1 21q22.3 RN, FP793, U2AF35, U2AFBP, RNU2AF1 -U2AF1 and Chronic Myelogenous Leukemia
IRF4 6p25.3 MUM1, LSIRF, SHEP8, NF-EM5 -IRF4 Expression in Chronic Myeloid Leukemia
HCK 20q11.21 JTK9, p59Hck, p61Hck -HCK and Chronic Myelogenous Leukemia
MSI2 17q22 MSI2H -MSI2 and Chronic Myelogenous Leukemia
GAB2 11q14.1 -GAB2 and Chronic Myelogenous Leukemia
GUSB 7q11.21 BG, MPS7 -GUSB and Chronic Myelogenous Leukemia
SLC9A1 1p36.11 APNH, NHE1, LIKNS, NHE-1, PPP1R143 -SLC9A1 and Chronic Myelogenous Leukemia
ESPL1 12q13.13 ESP1, SEPA -ESPL1 and Chronic Myelogenous Leukemia
ZRSR2 Xp22.2 URP, ZC3H22, U2AF1L2, U2AF1RS2, U2AF1-RS2 -ZRSR2 and Chronic Myelogenous Leukemia
BACH2 6q15 BTBD25 -BACH2 and Chronic Myelogenous Leukemia
PRDM16 1p36.32 MEL1, KMT8F, LVNC8, PFM13, CMD1LL -PRDM16 and Chronic Myelogenous Leukemia
CD59 11p13 1F5, EJ16, EJ30, EL32, G344, MIN1, MIN2, MIN3, MIRL, HRF20, MACIF, MEM43, MIC11, MSK21, 16.3A5, HRF-20, MAC-IP, p18-20 -CD59 and Chronic Myelogenous Leukemia
TRA 14q11.2 IMD7, TCRA, TCRD, TRA@, TRAC -TRA and Chronic Myelogenous Leukemia
ATG7 3p25.3 GSA7, APG7L, APG7-LIKE -ATG7 and Chronic Myelogenous Leukemia
RAC2 22q13.1 Gx, EN-7, HSPC022, p21-Rac2 -RAC2 and Chronic Myelogenous Leukemia
HDGF 1q23.1 HMG1L2 -HDGF and Chronic Myelogenous Leukemia
RIN1 11q13.2 -RIN1 and Chronic Myelogenous Leukemia
PDCD5 19q13.11 TFAR19 -PDCD5 and Chronic Myelogenous Leukemia
ARHGAP26 5q31.3 GRAF, GRAF1, OPHN1L, OPHN1L1 -ARHGAP26 and Chronic Myelogenous Leukemia
CD55 1q32.2 CR, TC, DAF, CROM, CHAPLE -CD55 and Chronic Myelogenous Leukemia
IRF2 4q35.1 IRF-2 -IRF2 and Chronic Myelogenous Leukemia
RPN1 3q21.3 OST1, RBPH1 -RPN1 and Chronic Myelogenous Leukemia
ABI2 2q33 ABI-2, ABI2B, AIP-1, AblBP3, argBP1, SSH3BP2, argBPIA, argBPIB -ABI2 and Chronic Myelogenous Leukemia
SRSF2 17q25.1 SC35, PR264, SC-35, SFRS2, SFRS2A, SRp30b -SRSF2 and Chronic Myelogenous Leukemia
XPO1 2p15 emb, CRM1, exp1 -XPO1 and Chronic Myelogenous Leukemia
RNF217-AS1 6q22.31 STL -STL and Chronic Myelogenous Leukemia
PLCD1 3p22.2 NDNC3, PLC-III -PLCD1 and Chronic Myelogenous Leukemia
CBLB 3q13.11 Cbl-b, RNF56, Nbla00127 -CBLB and Chronic Myelogenous Leukemia
HLA-DPB1 6p21.32 DPB1, HLA-DP, HLA-DPB, HLA-DP1B -HLA-DPB1 and Chronic Myelogenous Leukemia
PDCD1LG2 9p24.1 B7DC, Btdc, PDL2, CD273, PD-L2, PDCD1L2, bA574F11.2 -PDCD1LG2 and Chronic Myelogenous Leukemia
MAFG 17q25.3 hMAF -MAFG and Chronic Myelogenous Leukemia
ENDOU 12q13.1 P11, PP11, PRSS26 -ENDOU and Chronic Myelogenous Leukemia
SEPTIN5 22q11.21 H5, SEPT5, CDCREL, PNUTL1, CDCREL1, CDCREL-1, HCDCREL-1 -SEPT5 and Chronic Myelogenous Leukemia
CBLC 19q13.32 CBL-3, RNF57, CBL-SL -CBLC and Chronic Myelogenous Leukemia
ZNF384 12p13.31 NP, CIZ, NMP4, CAGH1, ERDA2, TNRC1, CAGH1A -ZNF384 and Chronic Myelogenous Leukemia
CEACAM3 19q13.2 CEA, CGM1, W264, W282, CD66D -CEACAM3 and Chronic Myelogenous Leukemia
HINT1 5q23.3 HINT, NMAN, PKCI-1, PRKCNH1 -HINT1 and Chronic Myelogenous Leukemia
FGFR1OP 6q27 FOP -FGFR1OP and Chronic Myelogenous Leukemia
HOXC11 12q13.13 HOX3H -HOXC11 and Chronic Myelogenous Leukemia
IFNA2 9p21.3 IFNA, INFA2, IFNA2B, IFN-alphaA -IFNA2 and Chronic Myelogenous Leukemia
PRTN3 19p13.3 MBN, MBT, NP4, P29, PR3, ACPA, AGP7, NP-4, PR-3, CANCA, C-ANCA -PRTN3 and Chronic Myelogenous Leukemia
IFNA7 9p21.3 IFNA-J, IFN-alphaJ -IFNA7 and Chronic Myelogenous Leukemia
IFNA17 9p21.3 IFNA, INFA, LEIF2C1, IFN-alphaI -IFNA17 and Chronic Myelogenous Leukemia
ABL1 9q34.12 ABL, JTK7, p150, c-ABL, v-abl, c-ABL1, bcr/abl Translocation
-BCR-ABL Translocation in Chronic Myeloid Leukaemia

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Research Publications

Millett R, Aggarwal A, Tabbara I, Nassereddine S
Chronic Myeloid Leukemia as Secondary Malignancy Following the Treatment of Hodgkin Lymphoma: A Case Series.
Anticancer Res. 2019; 39(8):4333-4335 [PubMed] Related Publications
Secondary malignancies are relatively common and clinically important phenomena following both chemotherapy and radiotherapy. The majority of these cases are acute leukemias, the occurrence of which have been thoroughly documented and studied. More rarely, chronic myeloid leukemias (CML) may arise subsequent to treatment of a primary malignancy. Literature review on such developments following treatment of Hodgkin's Lymphoma (HL) is scant. Herein, the authors present three cases of CML diagnosed within five years of treatment initiation for Hodgkin's Lymphoma (HL); one of the three patients had CML with atypical variant carrying a rare mutation with BCR-JAK2 fusion.

Massimino M, Stella S, Tirrò E, et al.
Efficacy of Dasatinib in a Very Elderly CML Patient Expressing a Rare E13a3
Anticancer Res. 2019; 39(7):3949-3954 [PubMed] Related Publications
We report the case of an 89-year-old male diagnosed with chronic-phase CML and expressing a rare e13a3 BCR-ABL1 fusion transcript. His cytogenetic analysis showed the t(9;22) translocation generating the Philadelphia chromosome (Ph), with a multiplex RT-PCR detecting an atypical fragment. Using two primers complementary to exon 10 of BCR and exon 4 of ABL1, a larger PCR product was observed, where after Sanger sequencing, an e13a3 BCR-ABL1 transcript was revealed. Given the diagnosis, the patient received 100 mg of dasatinib every other day and was then monitored by measuring both hematological and cytogenetic parameters, while his BCR-ABL1 transcripts were examined by PCR and semi-nested-PCR. According to the 2013 European Leukemia Network criteria, after six months of dasatinib the patient's response was classified as warning as he displayed 20% of Philadelphia-positive metaphases. Sequencing of the ABL1 catalytic domain did not detect point mutations. A complete cytogenetic response was achieved after one year of dasatinib. However, semi-nested-PCR confirmed the presence of the e13a3 BCR-ABL1 fusion transcript that has persisted up to the latest follow-up visit.

Tirrò E, Massimino M, Stella S, et al.
Efficacy of Nilotinib in a CML Patient Expressing the Three-way Complex Variant Translocation t(2;9;22).
Anticancer Res. 2019; 39(7):3893-3899 [PubMed] Related Publications
BACKGROUND/AIM: Chronic myelogenous leukemia (CML) is characterized by the presence of the Philadelphia chromosome, resulting from the reciprocal translocation involving chromosomes 9 and 22. About 5-10% of newly diagnosed patients in chronic-phase (CP) CML show complex additional chromosomal aberrations (ACA), that may involve one or more chromosomes in addition to 9 and 22. Data concerning the prognostic significance of ACA in CP-CML subjects at diagnosis are controversial. Furthermore, there is no evidence showing that selection of imatinib (IM) or second-generation tyrosine kinase inhibitors (2G-TKI) would be of benefit for these patients.
CASE REPORT: We report the three-way complex variant translocation t(2;9;22) in a CP-CML patient. Conventional cytogenetic analysis was employed to identify the ACA. Multiplex reverse transcription-PCR was used to identify the BCR-ABL1 transcript and its levels were measured using quantitative real-time-PCR. This rare ACA t(2;9;22) in our young patient displayed primary resistance to IM, but was responsive to second-line treatment with nilotinib.
CONCLUSION: CP-CML patients exhibiting this rare aberration at diagnosis may benefit from a 2G-TKI therapy compared to IM.

Zhang ZH, Lian XY, Li XX, et al.
[Clinical Study of SCIN Expression and Dromoter Methylation in Patients with Chronic Myeloid Leukemia].
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2019; 27(3):646-651 [PubMed] Related Publications
OBJECTIVE: To investigate the clinical significance of SCIN gene expression and promoter methylation in patients with chronic myeloid leukemia (CML).
METHODS: Real-time quantitative PCR was used to detect the expression level of SCIN in mononucleatr cells of bone marrow samples from 64 CML patients and 37 controls. The methylation levels of SCIN promoter in 65 patients with CML and 29 controls were detected by real-time quantitative methylation-specific PCR and bisulfite sequencing PCR.
RESULTS: The expression level of SCIN in CML patients was significantly down-regulated (P<0.05), compared with the control group. The down-regulation rate of SCIN expression in CML patients at chronic phase, accelerated phase and blast crisis was 61%, 67% and 75%, respectively. Spearman correlation analysis showed that the expression level of SCIN negatively correlated with the transcript level of BCR-ABL1 (R=-0.315, P<0.05). However, there was no significant difference in clinical parameters such as sex, age, white blood cell count, hemoglobin level, platelet count, chromosome, CML staging and BCL-ABL1 transcript level between low and high SCIN expression groups of CML patients (P>0.05). No significant difference in methylation of SCIN promoter between CML patients and controls, and no correlation between SCIN expression and promoter methylation were observed (P>0.05).
CONCLUSION: The SCIN expression is down-regulated in CML patients, which may relate with the pathogenesis that is, BCR-ABL1 fusion gene induces CML tumorigenesis. The down-regulation of SCIN expression may relate with the progression of CML.

Xu J, Wu M, Zhu S, et al.
Detecting the stable point of therapeutic effect of chronic myeloid leukemia based on dynamic network biomarkers.
BMC Bioinformatics. 2019; 20(Suppl 7):202 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Most researches of chronic myeloid leukemia (CML) are currently focused on the treatment methods, while there are relatively few researches on the progress of patients' condition after drug treatment. Traditional biomarkers of disease can only distinguish normal state from disease state, and cannot recognize the pre-stable state after drug treatment.
RESULTS: A therapeutic effect recognition strategy based on dynamic network biomarkers (DNB) is provided for CML patients' gene expression data. With the DNB criteria, the DNB with 250 genes is selected and the therapeutic effect index (TEI) is constructed for the detection of individual disease. The pre-stable state before the disease condition becomes stable is 1 month. Through functional analysis for the DNB, some genes are confirmed as key genes to affect the progress of CML patients' condition.
CONCLUSIONS: The results provide a certain theoretical direction and theoretical basis for medical personnel in the treatment of CML patients, and find new therapeutic targets in the future. The biomarkers of CML can help patients to be treated promptly and minimize drug resistance, treatment failure and relapse, which reduce the mortality of CML significantly.

Sheng Y, Ji Z, Zhao H, et al.
Downregulation of the histone methyltransferase SETD2 promotes imatinib resistance in chronic myeloid leukaemia cells.
Cell Prolif. 2019; 52(4):e12611 [PubMed] Related Publications
OBJECTIVES: Epigenetic modifiers were important players in the development of haematological malignancies and sensitivity to therapy. Mutations of SET domain-containing 2 (SETD2), a methyltransferase that catalyses the trimethylation of histone 3 on lysine 36 (H3K36me3), were found in various myeloid malignancies. However, the detailed mechanisms through which SETD2 confers chronic myeloid leukaemia progression and resistance to therapy targeting on BCR-ABL remain unclear.
MATERIALS AND METHODS: The level of SETD2 in imatinib-sensitive and imatinib-resistant chronic myeloid leukaemia (CML) cells was examined by immunoblotting and quantitative real-time PCR. We analysed CD34
RESULTS: SETD2 was found to act as a tumour suppressor in CML. The novel oncogenic targets MYCN and ERG were shown to be the direct downstream targets of SETD2, where their overexpression induced by SETD2 knockdown caused imatinib insensitivity and leukaemic stem cell enrichment in CML cell lines. Treatment with JIB-04, an inhibitor that restores H3K36me3 levels through blockade of its demethylation, successfully improved the cell imatinib sensitivity and enhanced the chemotherapeutic effect.
CONCLUSIONS: Our study not only emphasizes the regulatory mechanism of SETD2 in CML, but also provides promising therapeutic strategies for overcoming the imatinib resistance in patients with CML.

Luo N, Xia Q, Zhang L, et al.
One-step discrimination of BCR/ABL
Anal Chim Acta. 2019; 1067:129-136 [PubMed] Related Publications

Kizilors A, Crisà E, Lea N, et al.
Effect of low-level BCR-ABL1 kinase domain mutations identified by next-generation sequencing in patients with chronic myeloid leukaemia: a population-based study.
Lancet Haematol. 2019; 6(5):e276-e284 [PubMed] Related Publications
BACKGROUND: Kinase domain mutations in BCR-ABL1 are associated with resistance to tyrosine kinase inhibitors in patients with chronic myeloid leukaemia. Next-generation sequencing (NGS) allows detection of low-level kinase domain mutations, but its relevance in clinical practice remains debated. We aimed to examine the clinical effects of low-level kinase domain mutations identified using NGS in patients with chronic myeloid leukaemia.
METHODS: In this population-based study, we included consecutive patients newly diagnosed with chronic myeloid leukaemia treated with first-line tyrosine kinase inhibitors, and patients identified at the time of resistance to first-line treatment with imatinib at six institutions (teaching hospitals and district hospitals) in southeast England. We screened patients for BCR-ABL1 kinase domain mutations using NGS, irrespective of patient response to tyrosine kinase inhibitor therapy. When we detected a mutation with NGS, we retrospectively analysed all previous samples to establish the date of first occurrence and subsequent kinetics of the mutant subclone (or subclones). The primary endpoints of this study were progression-free and event-free survival at 5 years.
FINDINGS: Between Feb 1, 2007, and Dec 31, 2014, we screened 121 patients with chronic myeloid leukaemia for BCR-ABL1 kinase domain mutation. 99 consecutive patients were newly diagnosed, with available sequential RNA stored. The remaining 22 patients were diagnosed between June 1, 1999, and June 30, 2006, and were screened at the time of resistance to first-line treatment with imatinib. Imatinib was the first-line treatment for 111 patients, nilotinib for seven patients, and dasatinib for three patients. We detected a kinase domain mutation in 25 (21%) of 121 patients. Low-level kinase domain mutations were first identified in 17 (68%) of 25 patients with mutation. For patients with a complete cytogenetic response, 13 (14%) of 93 patients screened had a mutation. Five (71%) of the seven patients with a clinically relevant mutation lost complete cytogenetic response compared with 15 (17%) of 86 patients without a clinically relevant mutation (80 patients without mutation and six patients with a tyrosine kinase inhibitor-sensitive mutation, p=0·0031). Patients harbouring a mutant clone had poorer 5-year progression-free survival (65·3% [95% CI 40·5-81·8] vs 86·9% [75·8-93·2]; p=0·0161) and poorer 5-year event-free survival (22·2% [CI 5·6-45·9] vs 62·0% [50·4-71·6]; p<0·0001) than did patients without a mutation. We identified a kinase domain mutation in four (10%) of 41 patients with samples available at 3 months after starting first-line tyrosine kinase inhibitor treatment; all four subsequently progressed to accelerated phase disease compared with only three (8%) of 37 without a mutation (p<0·0001).
INTERPRETATION: NGS reliably and consistently detected early appearance of kinase domain mutations that would not otherwise be detected by Sanger sequencing. For the first time, to our knowledge, we report the presence of kinase domain mutations after only 3 months of therapy, which could have substantial clinical implications. NGS will allow early clinical intervention and our findings will contribute to the establishment of new recommendations on the frequency of kinase domain mutation analysis to improve patient clinical care.

Vatanmakanian M, Tavallaie M, Ghadami S
Imatinib independent aberrant methylation of NOV/CCN3 in chronic myelogenous leukemia patients: a mechanism upstream of BCR-ABL1 function?
Cell Commun Signal. 2019; 17(1):38 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The NOV gene product, CCN3, has been reported in a diverse range of tumors to serve as a negative growth regulator, while acting as a tumor suppressor in Chronic Myelogenous Leukemia (CML). However, the precise mechanism of its silencing in CML is poorly understood. In the current study, we aimed to query if the gene regulation of CCN3 is mediated by the promoter methylation in the patients with CML. In addition, to clarify whether the epigenetic silencing is affected by BCR-ABL1 inhibition, we assessed the methylation status in the patients at different time intervals following the tyrosine kinase inhibition using imatinib therapy, as the first-line treatment for this type of leukemia.
METHODS: To address this issue, we applied bisulfite-sequencing technique as a high-resolution method to study the regulatory segment of the CCN3 gene. The results were analyzed in newly diagnosed CML patients as well as following imatinib therapy. We also evaluated the correlation of CCN3 promoter methylation with BCR-ABL1 levels.
RESULTS: Our findings revealed that the methylation occurs frequently in the promoter region of CML patients showing a significant increase of the methylated percentage at the CpG sites compared to normal individuals. Interestingly, this hypermethylation was indicated to be independent of BCR-ABL1 titers in both groups, which might suggest a mechanism beyond the BCR-ABL1 function.
CONCLUSION: Despite suggesting that the CCN3 hypermethylation acts as a molecular mechanism independent of BCR-ABL1 function in CML patients, this scenario requires further validation by complementary experiments. In the case of acting upstream of BCR-ABL1 signaling, the methylation marker can provide early detection and a novel platform for targeted epigenetic modifiers for efficient treatment in imatinib resistant patients.

Sazawal S, Chhikara S, Singh K, et al.
Distribution of common BCR-ABL fusion transcripts and their impact on treatment response in Imatinib treated CML patients: A study from India.
Indian J Pathol Microbiol. 2019 Apr-Jun; 62(2):256-260 [PubMed] Related Publications
Background: Philadelphia chromosome (Ph): Hallmark of CML is caused by reciprocal translocation between chromosomes 9 and 22 resulting in BCR-ABL fusion protein. Most commonly associated breakpoint with CML is M-bcr in exon 13 or exon 14, producing splice variant b2a2 or b3a2 respectively. The distribution of these transcripts and their influence on clinico-hematological parameters is variable. Impact of the fusion transcripts on treatment outcome in Imatinib treated CML patients is still a matter of debate.
Aims/settings and design: We conducted this study on 400 CML-CP patients to look for the distribution of fusion transcripts i.e. b3a2 and b2a2, their clinico-hematological profile and impact on treatment response in patients treated with Imatinib.
Material and Methods: CML-CP was diagnosed by reverse transcriptase PCR (RT-PCR) for the BCR-ABL fusion transcript. Real-time quantitative PCR (RQ-PCR) was performed on peripheral blood every 3-6 monthly to look for treatment response.
Results: The overall frequency of b3a2 transcript was observed in 288 (72%) followed by b2a2 in 104 (26%) and hybrid fusion transcript (b3a2 + b2a2) was seen in 8 (2%) cases. MMR was attained in 198/288 (68.7%) patients with b3a2 transcript and 90/288 (31.3%) patients failed to achieve MMR after 12 months of Imatinib therapy. Among the patients with b2a2 transcript, 44/104 (42.3%) patients achieved MMR and 60/104 (57.7%) patients failed to achieve MMR after 12 months of Imatinib therapy.
Conclusions: In conclusion, the frequency of b3a2 transcript was more as compared to b2a2 transcript. MMR was significantly higher in patients with b3a2 transcript as compared to patients with b2a2.

Wang X, Yang J, Guo G, et al.
Novel lncRNA-IUR suppresses Bcr-Abl-induced tumorigenesis through regulation of STAT5-CD71 pathway.
Mol Cancer. 2019; 18(1):84 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Long noncoding RNAs (lncRNAs), defined as the transcripts longer than 200 nt without protein-coding capacity, have been found to be aberrantly expressed in diverse human diseases including cancer. A reciprocal translocation between chromosome 9 and 22 generates the chimeric Bcr-Abl oncogene, which is associated with several hematological malignancies. However, the functional relevance between aberrantly expressed lncRNAs and Bcr-Abl-mediated leukemia remains obscure.
METHODS: LncRNA cDNA microarray was used to identify novel lncRNAs involved in Bcr-Abl-mediated cellular transformation. To study the functional relevance of novel imatinib-upregulated lncRNA (IUR) family in Abl-induced tumorigenesis, Abl-transformed cell survival and xenografted tumor growth in mice was evaluated. Primary bone marrow transformation and in vivo leukemia transplant using lncRNA-IUR knockdown (KD) transgenic mice were further conducted to corroborate the role of lncRNA-IUR in Abl-induced tumorigenesis. Transcriptome RNA-seq, Western blot, RNA pull down and RNA Immunoprecipitation (RIP) were employed to determine the mechanisms by which lncRNA-IUR-5 regulates Bcr-Abl-mediated tumorigenesis.
RESULTS: We identified a conserved lncRNA-IUR family as a key negative regulator of Bcr-Abl-induced tumorigenesis. Increased expression of lncRNA-IUR was detected in both human and mouse Abl-transformed cells upon imatinib treatment. In contrast, reduced expression of lncRNA-IUR was observed in the peripheral blood lymphocytes derived from Bcr-Abl-positive acute lymphoblastic leukemia (ALL) patients compared to normal subjects. Knockdown of lncRNA-IUR remarkably promoted Abl-transformed leukemic cell survival and xenografted tumor growth in mice, whereas overexpression of lncRNA-IUR had opposite effects. Also, silencing murine lncRNA-IUR promoted Bcr-Abl-mediated primary bone marrow transformation and Abl-transformed leukemia cell survival in vivo. Besides, knockdown of murine lncRNA-IUR in transgenic mice provided a favorable microenvironment for development of Abl-mediated leukemia. Finally, we demonstrated that lncRNA-IUR-5 suppressed Bcr-Abl-mediated tumorigenesis by negatively regulating STAT5-mediated expression of CD71.
CONCLUSIONS: The results suggest that lncRNA-IUR may act as a critical tumor suppressor in Bcr-Abl-mediated tumorigenesis by suppressing the STAT5-CD71 pathway. This study provides new insights into functional involvement of lncRNAs in leukemogenesis.

Möbius S, Schenk T, Himsel D, et al.
Results of the European survey on the assessment of deep molecular response in chronic phase CML patients during tyrosine kinase inhibitor therapy (EUREKA registry).
J Cancer Res Clin Oncol. 2019; 145(6):1645-1650 [PubMed] Related Publications
PURPOSE: The advent of tyrosine kinase inhibitor (TKI) therapies has revolutionized the treatment of chronic myeloid leukemia (CML). The European LeukemiaNet (ELN) recommends quantification of BCR-ABL1 transcripts by real-time quantitative PCR every 3 months during TKI treatment. Since a proportion of patients in deep molecular response (DMR: MR
METHODS: Data were collected on the standardized assessment of molecular response in the context of real-life practice. BCR-ABL1 transcript levels after > 2 years of TKI therapy were evaluated for DMR by local laboratories as well as standardized EUTOS laboratories. Since standardized molecular monitoring is a prerequisite for treatment discontinuation, central surveillance of the performance of the participating laboratories was carried out.
RESULTS: Between 2014 and 2017, 3377 peripheral blood samples from 1117 CML patients were shipped to 11 standardized reference laboratories in six European countries. BCR-ABL1 transcript types were b3a2 (41.63%), b2a2 (29.99%), b2a2/b3a2 (3.58%) and atypical (0.54%). For 23.72% of the patients, the initial transcript type had not been reported. Response levels (EUTOS laboratory) were: no MMR, n = 197 (6.51%); MMR, n = 496 (16.40%); MR
CONCLUSIONS: Multicenter DMR assessment is feasible in the context of real-life clinical practice in Europe. Information on the BCR-ABL1 transcript type at diagnosis is crucial to accurately monitor patients' molecular response during or after TKI therapy.

Hassan FM
OGG1 rs1052133 Polymorphism and Genetic Susceptibility to Chronic Myelogenous Leukaemia
Asian Pac J Cancer Prev. 2019; 20(3):925-928 [PubMed] Related Publications
Background: In some cancer cells, the OGG1 gene is somatically mutated and highly populated. This study was conducted to examine whether OGG1 rs1052133 polymorphism is associated with the genetic background of chronic myelogenous leukaemia (CML) in Sudan. Methods: A total of 332 CML patients and 70 healthy controls were included in this study. Overall, the genotypes (P=0.0000) and allele (C vs. G, P=0.0007) differed considerably in the frequencies of OGG1 rs1052133 polymorphism between CML patients and controls. Our study is the first to evaluate the association of polymorphism with CML risk with OGG1 rs1052133. Results: A statistically significant association was observed between the genotype distribution of OGG1 rs1052133 polymorphism and CML (P=0.0000) patients. A similar result was also observed in the allele distribution (C vs. G, P=0.0007) compared with healthy controls when compared OGG1 rs1052133 genotypes with CML stages. Results: Genotype and allele frequencies of OGG1 rs1052133 among CML patients. A statistically significant association was observed between the genotype distribution of the OGG1 rs1052133 polymorphism and CML patients (P=0.0000). A similar result was also observed in the allele distribution (C vs. G, P=0.0007) compared with healthy controls with stages of CML in OGG1 rs1052133 genotypes. Conclusion: The results suggest that single nucleotide polymorphism in the gene involved in the restoration of DNA base excision (OGG1 rs1052133) can play a key role in the risk of appearance of CML. To clarify the role of OGG1 in the genetic basis of CML, further case control with larger sample sizes and fine-mapping is required.

Grifoni FI, Sciumè M, Pravettoni V, et al.
A case report of systemic mastocytosis associated with multiple hematologic non-mast cell lineage diseases.
Hematol Oncol. 2019; 37(2):205-211 [PubMed] Related Publications
Systemic mastocytosis (SM) is a hematological malignancy characterized by extracutaneous infiltration by atypical mast cells. Together with indolent SM, aggressive SM, and mast cell leukemia, the World Health Organization (WHO) recognizes another major disease subgroup: SM with an associated hematological neoplasm, which is characterized by the presence of a concurrent neoplasm, more commonly, a chronic myelomonocytic leukemia. While KIT D816V is commonly regarded as the driver mutation, the clinical presentation of SM is extremely varied. Treatment of SM might not be simple, but now more specific therapies tailored toward prognostic subgroups of patients have been developed. Here, we report a detailed description of clinical management and biological features of a systemic mastocytocis case associated with multiple hematologic non-mast cell lineage diseases.

Gong J, Li J, Gai Y, et al.
[Co-occurrence of t(8;21)(q22;q22) and t(9;22)(q34;q11) in a case with chronic myelogenous leukemia].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2019; 36(3):253-256 [PubMed] Related Publications
OBJECTIVE: To delineate laboratory and clinical characteristics of a case with chronic myelogenous leukemia (CML) and co-occurrence of t(9;22)(q34;q11) and t(8;21)(q22;q22).
METHODS: The patient was subjected to cytogenetic, molecular, morphological and immunophenotypic analyses.
RESULTS: Cytogenetic analysis revealed presence of t(8;21)(q22;q22) in addition to t(9;22)(q34;q11) in the patient. Chimeric BCR/ABL and AML1/ETO genes were detected by fluorescence in situ hybridization (FISH). Transcripts of BCR/ABL210 and AML1/ETO fusion genes were detected by relative quantity PCR. Morphological study suggested that the patient was at the chronic phase of CML. No significant immunophenotypic abnormality was detected by flow cytometry.
CONCLUSION: Co-occurrence of t(8;21)(q22;q22) and t(9;22)(q34;q11) is rare in CML. Only 5 similar cases have been described previously. This case suggested that chromosomal alterations may precede morphological, flow cytometric and clinical changes and accelerate progression of the disease.

Dulucq S, Etienne G, Morisset S, et al.
Impact of second decline rate of BCR-ABL1 transcript on clinical outcome of chronic phase chronic myeloid leukemia patients on imatinib first-line.
Ann Hematol. 2019; 98(5):1159-1168 [PubMed] Related Publications
Early molecular response has been associated with clinical outcome in chronic myeloid leukemia (CML) patients treated with tyrosine kinase inhibitors. The BCR-ABL1 transcript rate decline from baseline to 3 months has been demonstrated to be more predictive than a single BCR-ABL1 level at 3 months (M3). However, it cannot be used routinely because ABL1, as an internal gene control, is not reliable for BCR-ABL1 quantification above 10%. This study aimed to compare clinical outcome and molecular response of chronic phase CML patients, depending on the percentage of BCR-ABL1 transcript decrease from month 3 to month 6 using ABL1 as an internal control gene. Two hundred sixteen chronic phase CML patients treated with imatinib 400 mg for whom M3 and month 6 molecular data were available were included in the study. Associations with event-free (EFS), failure-free (FFS), progression-free (PFS), and overall survivals (OS) molecular response 4 log and 4.5 log were assessed. The percentage of BCR-ABL1 decline from month 3 to month 6 was significantly linked to the EFS and the FFS (p < 0.001). A common cut-off of 67% of decline predicted the better risk of event. Patients with a decrease below 67% have worse EFS and FFS as compared to those having a higher decrease (p < 0.001). The impact was confirmed by multivariate analysis. Since the slope between diagnosis and 3 months cannot be reliable using ABL1 as an internal gene control, the second decline rate of BCR-ABL1 transcript between month 3 and month 6 could efficiently identify patients at higher risk of event.

Ferri C, Weich N, Gutiérrez L, et al.
Single nucleotide polymorphism in PTEN-Long gene: A risk factor in chronic myeloid leukemia.
Gene. 2019; 694:71-75 [PubMed] Related Publications
The BCR-ABL1 oncogene is associated with chronic myeloid leukemia (CML) pathogenesis, but the molecular mechanisms that initiate leukemogenesis are still unclear. Cancer pathogenesis has been associated with genetic alterations that may lead to inactivation of tumor suppressor genes. Phosphatase and tensin homolog (PTEN) is frequently deleted or inactivated in various tumors. A recently discovered variant of PTEN, PTEN-Long (PTEN-L), results from an alternative translation initiation site located upstream of the canonic AUG and generates a protein of 576 amino acids instead the expected protein of 403 amino acids. A 16 bp perfect palindromic motif centered on the PTEN-L CUG

Baccarani M, Castagnetti F, Gugliotta G, et al.
The proportion of different BCR-ABL1 transcript types in chronic myeloid leukemia. An international overview.
Leukemia. 2019; 33(5):1173-1183 [PubMed] Related Publications
There are different BCR-ABL1 fusion genes that are translated into proteins that are different from each other, yet all leukemogenic, causing chronic myeloid leukemia (CML) or acute lymphoblastic leukemia. Their frequency has never been systematically investigated. In a series of 45503 newly diagnosed CML patients reported from 45 countries, it was found that the proportion of e13a2 (also known as b2a2) and of e14a2 (also known as b3a2), including the cases co-expressing e14a2 and e13a2, was 37.9% and 62.1%, respectively. The proportion of these two transcripts was correlated with gender, e13a2 being more frequent in males (39.2%) than in females (36.2%), was correlated with age, decreasing from 39.6% in children and adolescents down to 31.6% in patients ≥ 80 years old, and was not constant worldwide. Other, rare transcripts were reported in 666/34561 patients (1.93%). The proportion of rare transcripts was associated with gender (2.27% in females and 1.69% in males) and with age (from 1.79% in children and adolescents up to 3.84% in patients ≥ 80 years old). These data show that the differences in proportion are not by chance. This is important, as the transcript type is a variable that is suspected to be of prognostic importance for response to treatment, outcome of treatment, and rate of treatment-free remission.

Uzoma IC, Taiwo IA, Nna EO, et al.
Detection of
Niger J Clin Pract. 2019; 22(1):51-55 [PubMed] Related Publications
Background: The presence of BCR-ABL1 fusion gene resulting from a t(9; 22) reciprocal chromosome translocation is the molecular hallmark of chronic myeloid leukemia (CML). In the diagnosis and treatment of CML, peripheral blood or bone marrow samples are usually taken for analysis. However, both methods are invasive sample collection methods, thus a noninvasive saliva sample method for the detection of the fusion gene transcripts (BCR-ABL) was investigated in some Nigerians with CML.
Materials and Methods: Real-time (RT)-polymerase chain reaction (PCR) analysis was used to detect BCR-ABL1 fusion gene in the saliva and blood of 42 Nigerian CML patients. RNA was extracted using RNeasy kit and reverse transcribed by random hexamer priming using murine Moloney reverse transcriptase. BCR-ABL1 transcript types were first detected by multiplex PCR and then quantified by a duplex RT-PCR-TaqMan chemistry with MGB probe and Black Hole Quencher.
Results: Of the 42 subjects, transcript types were detected in 36 (85.7%) samples, e13a2 fusion transcript sub-type was detected in 9 (21.4%), whereas e14a2 subtype was found in 27 (67.3%); six (14.3%) of the samples did not reveal any of the fusion transcript subtypes. The median BCR-ABL1 messenger RNA values were 9.38 × 10
Conclusion: Saliva may offer an alternative easy-to-collect, readily available, and noninvasive sample for the diagnosis and treatment of CML.

Farawela HM, Zawam HM, Al-Wakeel HA, et al.
Expression pattern and prognostic implication of SALL4 gene in myeloid leukemias: a case-control study.
Scand J Clin Lab Invest. 2019 Feb - Apr; 79(1-2):65-70 [PubMed] Related Publications
SALL4 is a transcription factor that retains stem cells in an undifferentiated state and promotes its self-renewal. In addition, it is implicated in leukemogenesis via its effect on leukemic stem cells. This study aimed to characterize the expression pattern of SALL4 gene in acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) at different progression phases of the leukemic process and to assess its prognostic significance. Real-time PCR was used in 106 patients: 54 AML patients; 43 de novo and 11 in complete remission (CR), 52 CML patients; 31 in chronic phase (CP), 11 in deep molecular response (MR

Shvachko LP, Zavelevich MP, Gluzman DF, et al.
Vitamin Е activates expression of С/EBP alpha transcription factor and G-CSF receptor in leukemic K562 cells.
Exp Oncol. 2018; 40(4):328-331 [PubMed] Related Publications
BACKGROUND: Chronic myeloid leukemia (CML) is a clonal hematopoietic stem cell disorder associated with the activity of BCR-ABL fusion oncogene. Tyrosine kinase inhibitors are the current treatment of CML, but secondary mutations finally contribute to therapy resistance and blast crisis of the disease. The search for the novel compounds for the effective control of CML is now in the spotlight. The progression of CML to blast crisis is correlated with down-modulation of C/EBP alpha. Therefore, C/EBP alpha may be considered as a putative target in differentiation therapies in myeloid leukemias. The aim of the study was to assess the potential of vitamin E as the possible inducer of C/EBP alpha expression in BCR-ABL-positive CML K562 cells.
MATERIALS AND METHODS: RNA extracted from K562 cells cultured with valproic acid or vitamin E was converted to cDNA, RT-PCR reactions were carried out using HotStarTaq DNA polymerase with primers for C/EBP alpha and granulocyte colony-stimulating factor receptor (G-CSFR).
RESULTS: We have not found detectable expression of C/EBP alpha in K562 cells. Upon 48-h culture with vitamin E at a dose of 100 µM, K562 cells expressed both C/EBP alpha and G-CSFR.
CONCLUSION: Vitamin E restored the expression of C/EBP alpha mRNA in chronic myelogenous leukemia K562 cells. In this setting, G-CSFR expression in vitamin E treated K562 cells seems to suggest the activation to granulocytic differentiation. It should be further elucidated whether such effects of vitamin E on C/EBP alpha transcription factor are direct or mediated indirectly due to antioxidant properties of vitamin E.

Stella S, Massimino M, Tirrò E, et al.
B-ALL Relapses After Autologous Stem Cell Transplantation Associated With a Shift from e1a2 to e14a2
Anticancer Res. 2019; 39(1):431-435 [PubMed] Related Publications
BACKGROUND/AIM: The Philadelphia chromosome is found in 30% of acute lymphoblastic leukemia (ALL) patients, a distinct ALL subgroup where the BCR-ABL fusion gene is associated with poor prognosis. Treatment with tyrosine kinase inhibitors (TKIs) often induces complete remission and these patients subsequently undergo an autologous stem cell transplantation (ASCT). However, 20% of subjects experience a relapse associated with the selection of point-mutations in the BCR-ABL kinase domain. We report the clinical evolution of a Philadelphia-positive ALL patient co-expressing the e1a2 and e14a2 BCR-ABL transcript at diagnosis.
MATERIALS AND METHODS: Multiplex reverse transcriptase (RT)-PCR was used to detect BCR-ABL transcripts and their levels were measured by quantitative Real Time PCR. Clonal sequencing and next-generation sequencing (NGS) were used to identify mutations.
RESULTS: Although the patient underwent ASCT following treatment with multiple TKIs, he relapsed twice. The first time he exhibited the e1a2 transcript and the second time he presented only the e14a2 variant. Mutation analysis, performed by clonal sequencing and NGS, detected two alterations after the first relapse and a single mutation at the time of the second relapse.
CONCLUSION: The observed shift from the e1a2 to the e14a2 variant and the selection of TKI-resistant clones heavily contributed to the fatal evolution of the disease.

Mat Yusoff Y, Abu Seman Z, Othman N, et al.
Prevalence of BCR-ABL T315I Mutation in Malaysian Patients with Imatinib-Resistant Chronic Myeloid Leukemia
Asian Pac J Cancer Prev. 2018; 19(12):3317-3320 [PubMed] Free Access to Full Article Related Publications
Objective: Chronic Myeloid Leukemia (CML) is caused by a reciprocal translocation between chromosomes 9 and 22, t(9;22) (q34;q11) which encodes for the BCR-ABL fusion protein. Discovery of Imatinib Mesylate (IM) as first line therapy has brought tremendous improvement in the management of CML. However, emergence of point mutations within the BCR-ABL gene particularly T315I mutation, affects a common BCR-ABL kinase contact residue which impairs drug binding thus contribute to treatment resistance. This study aims to investigate the BCR-ABL T315I mutation in Malaysian patients with CML. Methods: A total of 285 patients diagnosed with CML were included in this study. Mutation detection was performed using qualitative real-time PCR (qPCR). Results: Fifteen out of 285 samples (5.26%) were positive for T315I mutations after amplification with real-time PCR assay. From the total number of positive samples, six patients were in accelerated phase (AP), four in chronic phase (CP) and five in blast crisis (BC). Conclusion: Mutation testing is recommended for choosing various tyrosine kinase inhibitors (TKIs) to optimize outcomes for both cases of treatment failure or suboptimal response to imatinib. Therefore, detection of T315I mutation in CML patients are clinically useful in the selection of appropriate treatment strategies to prevent disease progression.

Padaro E, Magnang H, Layibo Y, et al.
[Types of bcr-abl and their correlations with the blood count in chronic myeloid leukemia (CML) in Togo].
Pan Afr Med J. 2018; 30:221 [PubMed] Free Access to Full Article Related Publications
This study aims to describe the different bcr-abl gene transcript variants in order to determine their frequency and to study their influence on CBC diagnostic test. We conducted a cross-sectional study of 34 patients with chronic myeloid leukemia in Togo. The search for fusion transcripts was performed in the laboratory of biological haematology at the Henri Mondor Hospital, Créteil (France). The average age of patients was 42,32±14,87 years ranging between 9 and 65 years. Most patients were male, with a sex- ratio of 1.61 (21 men and 13 women). Molecular examination showed b3-a2 transcript and b2-a2 transcript. Nineteen patients (55.88%) expressed b3-a2 transcript, 13 patients (38.24%) b2-a2 transcript (32.10%) and two patients expressed both b3-a2 and b2-a2 transcripts (5.88%). At diagnosis, mean hemoglobin level, the average number of white blood cells and the average number of platelets in patients expressing b3-a2 transcript were 99,2g/L; 207,63g/l and 451,28g/l respectively. In patients expressing b2-a2 transcript values were 104,6g/l, 114,32g/l and 486,11g/l. In patients with both transcripts, values were 67g/L, 867g/l and 780g/l respectively. CBC parameters are more significantly altered in patients with both transcripts b3-a2 and b2-a2.

Xie W, Wang SA, Hu S, et al.
Myeloproliferative neoplasm with ABL1/ETV6 rearrangement mimics chronic myeloid leukemia and responds to tyrosine kinase inhibitors.
Cancer Genet. 2018; 228-229:41-46 [PubMed] Related Publications
Myeloproliferative neoplasms (MPN) associated with ABL1-ETV6 fusions are rare and poorly characterized. To date, less than 20 cases of ABL1-ETV6+ MPN have been reported. We report a 47-year-old man who presented with MPN with clinicopathologic features resembling chronic myeloid leukemia, but there was no evidence of t(9;22)(p34.1;q11.2) or BCR-ABL1 fusion. Conventional cytogenetics and fluorescence in situ hybridization analysis showed ins(12;9)(p13;q34q34) that led to ETV6-ABL1 fusion. The patient responded well to tyrosine kinase inhibitor therapy and achieved remission for 7 years.

Liu R, Zhang G, Yang Z
Towards rapid prediction of drug-resistant cancer cell phenotypes: single cell mass spectrometry combined with machine learning.
Chem Commun (Camb). 2019; 55(5):616-619 [PubMed] Free Access to Full Article Related Publications
Combined single cell mass spectrometry and machine learning methods is demonstrated for the first time to achieve rapid and reliable prediction of the phenotype of unknown single cells based on their metabolomic profiles, with experimental validation. This approach can be potentially applied towards prediction of drug-resistant phenotypes prior to chemotherapy.

Shanmuganathan N, Hughes TP
Molecular monitoring in CML: how deep? How often? How should it influence therapy?
Hematology Am Soc Hematol Educ Program. 2018; 2018(1):168-176 [PubMed] Article available free on PMC after 30/11/2019 Related Publications
With the advent of tyrosine kinase inhibitors (TKIs), the goals of therapy in chronic myeloid leukemia (CML) are steadily shifting. Long-term disease control on TKI therapy has been the goal and expectation for most patients. More recently, treatment-free remission (TFR) has entered mainstream practice and is increasingly being adopted as the main goal of therapy. This therapeutic shift not only influences TKI selection but also, has necessitated the refinement and dissemination of highly sensitive and accurate molecular monitoring techniques. Measurement of BCR-ABL1 messenger RNA expression through reverse transcription quantitative polymerase chain reaction, reported according to the International Scale, has become the primary tool for response assessment in CML. Achieving specific time-dependent molecular milestones, as defined by global therapeutic guidelines, has been established as critical in maximizing optimal outcomes while identifying patients at risk of therapy failure. Depth and duration of a deep molecular response have become the new therapeutic targets in patients considered for TFR. Consequently, molecular monitoring in CML has become even more critical to ongoing response assessment, identifying patients with TKI resistance and poor drug adherence, and enabling TFR to be attempted safely and effectively.

Kang KH, Kim SH, Choi SY, et al.
Compound mutations involving T315I and P-loop mutations are the major components of multiple mutations detected in tyrosine kinase inhibitor resistant chronic myeloid leukemia.
Leuk Res. 2019; 76:87-93 [PubMed] Related Publications
To analyze the pattern of multiple mutations detected by Sanger sequencing (SS), we performed subcloning sequencing using 218 samples from 45 patients with tyrosine kinase inhibitor resistant chronic myeloid leukemia. At the first time of multiple mutation detection by SS (baseline), a total of 19 major mutations from 45 samples were detected; these mutations were found in the following order: T315I (68.9%), E255 K (33.3%), Y253H (13.3%), G250E (13.3%), and F317 L (11.1%). Subcloning sequencing of 900 baseline colonies identified 556 different mutant types, and 791 among the 900 were colonies with major mutations (87.9%). The mutations were found in the following order: T315I (36.4%), E255 K (16.2%), Y253H (7.0%), G250E (6.7%), M351 T (6.6%), and E255 V (5.3%). In subcloning sequencing with 4357 colonies of 218 serial samples, 2506 colonies (57.5%) had compound mutations, among which 2238 colonies (89.3%) had at least one major mutation. The median number of mutations in compound mutant colonies was 2 (range, 2-7), and most were double (52.9%) or triple (28.7%) mutations. Additionally, some mutations in allosteric binding sites were detected as low level mutation in 13 patients. With the available retrospective samples before baseline, subcloning sequencing identified low-level mutations of various frequencies (median, 10%) to be major mutations in 20 patients. Thus, compound mutations involving T315I and P-loop mutations were the major components of multiple mutations, and some low-level mutations with potential clinical significance were detected by subcloning sequencing. Hence, more sensitive sequencing assays are needed in patients with multiple mutations.

Yang ZY, Zhang YS, Liang CX, Zhou ZJ
[Relation between single Nucleotide Polymorphisms of CYP3A5 Gene and MDR1 Gene Loci and Risk of CML Cytogenetic Relapse].
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2018; 26(6):1644-1648 [PubMed] Related Publications
OBJECTIVE: To analyze the relation between the signle nucleotide polymorphisms (SNP) of CYP3A5 gene and MDR1 gene loci and the risk of cytogenetic relapse in chronic myeloid leukemia (CML).
METHODS: The clinical data of 90 patients with CML treated with imatinib in our hospital were collected.The patients were divided into 2 groups: non-relapse and relapse according to relapse and non-relapse, then the relation between the SNP of CYP3A5 gene and MRD1 gene loci and the risk of cytogenetic relapse in CML patients.
RESULTS: The grouping result showed that the patients with non cytogenetic relapse accounted for 41 cases those were enrolled in non-relapse group, and patient-with cytogenetic relapse accounted for 49 cases those were enrolled in relapse group. The follow-up time was 36 months. The detection showed that the incidence of cytogenetic relapse in the patients with CC genotype was significantly higher than that in the patients with TT+CT genotype of C3435T and C1236T at MDR1 gene loci (P<0.05).Compared with the patients with CT+CC genotype in C3435T locus of MDR1 gene, the rate of cytogenetic relapse in the patients with TT genotype decreased significantly (P<0.05). Compared with patients with CT+CC phemotype of C3435T in MDR1 gene locus, the non-relapse survival time of TT genotypes was significantly prolonged (P<0.05). Compared with non-relapse group, the incidence of neutropenia (29.27% vs 71.43%) and blood toxicity (39.02% vs 61.22%) in the relapse group increased significantly (P<0.05). The imatinib dose (OR=2 95, 95% CI:1.37~7.76) and the C3435T genotype in MDR1 genes (OR=0.09, 95% CI:0.05~0.72) were the factors affecting the cytogenetic relapse of the patients with CML (both P<0.05).
CONCLUSION: The therapeutic dose of imatinib and the C3435T and C1236T genotypes in MDR1 gene have a certain effect on the cytogenetic relapse of CML patients. C3435T genotypes in the.MDR1 gene showed a certain predictive value for evaluating the risk of cytogenetic relapse, which can be used as a clinical biomarker.

Zhang J, Jiang Y, Han X, et al.
Differential expression profiles and functional analysis of plasma miRNAs associated with chronic myeloid leukemia phases.
Future Oncol. 2019; 15(7):763-776 [PubMed] Related Publications
AIM: This study was aimed to investigate the expression profiles and biological function of plasma miRNAs at different phases of chronic myeloid leukemia (CML).
MATERIALS & METHODS: Differentially expressed miRNAs were identified by microarray. The candidate miRNAs were validated by quantitative real-time PCR at chronic phase, accelerated phase and blast crisis. The functional analysis of miRNAs was carried out by using DAVID.
RESULTS: The putative targets of dysregulated miRNAs were involved in important signaling pathways. Plasma let-7b-5p and miR-451a expression was lower in CML patients, and plasma miR-451a gradually decreased from chronic phase to accelerated phase and blast crisis.
CONCLUSION: Dysregulated plasma miRNAs maybe play regulatory roles in pathogenesis of CML. Let-7b-5p and miR-451a can be used as potential biomarkers for the diagnosis and prognosis of CML.

Recurring Structural Abnormalities

Selected list of common recurrent structural abnormalities

Abnormality Type Gene(s)
BCR-ABL Translocation in Chronic Myeloid LeukaemiaTranslocationABL1 (9q34.12)BCR (22q11.23)

This is a highly selective list aiming to capture structural abnormalies which are frequesnt and/or significant in relation to diagnosis, prognosis, and/or characterising specific cancers. For a much more extensive list see the Mitelman Database of Chromosome Aberrations and Gene Fusions in Cancer.

Disclaimer: This site is for educational purposes only; it can not be used in diagnosis or treatment.

Cite this page: Cotterill SJ. Chronic Myeloid Leukemia, Cancer Genetics Web: Accessed:

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