ABL1

Primary Author(s)*

Brian Davis, PhD etc.

Synonyms

ABL proto-oncogene 1, non-receptor tyrosine kinase; Abelson tyrosine-protein kinase 1; ABL; JTK7; p150; c-ABL; v-abl; CHDSKM; c-ABL1; bcr/abl

Genomic Location

Cytoband: 9q34.12

Genomic Coordinates:

chr9:130,713,881-130,887,675(GRCh38/hg38)

chr9:133,589,268-133,763,062(GRCh37/hg19)

Cancer Category/Type

Chronic Myeloid Leukemia with BCR-ABL1 (also referred as (Chronic Myelogenous Leukemia))

More than 90% of patients diagnosed with Chronic Myeloid Leukemia have a Philadelphia chromosome resulting from t(9;22)(q34.1;q11.2), which is a reciprocal translocation between chromosome 22 (BCR locus) and chromosome 9 (ABL1 locus) (see OMIM) [1]. The Drug Imatinib mesylate, also known as Gleevec, was the one of the first molecularly developed drugs, and has a remarkably high success rate in treatment of patients with Chronic Myeloid Leukemia by targeting the BCR/ABL1 fusion product [5].

Acute Lymphoblastic Leukemia

Approximately 20% of patients (25 - 30% of adults and 2 - 10% of children) diagnosed with Acute Lymphoblastic Leukemia have a Philadelphia chromosome resulting from t(9;22)(q34.1;q11.2), which is a reciprocal translocation between chromosome 22 (BCR locus) and chromosome 9 (ABL1 locus) (see OMIM) [1]. Treatment of Acute Lymphoblastic Leukemia patients with Gleevec does not have the same success as in Chronic Myeloid Leukemia patients because the genomic instability of ALL cells contributes to point mutations arising in the BRC-ABL1 kinase domain, leading to Gleevec resistance [4].

Mixed Phenotype Acute Leukemia (MPAL) with BCR-ABL1

BCR-ABL1 translocations (Ph+) are more prevalent in adult vs. pediatric patients diagnosed as Mixed Phenotype Acute Leukemia (MPAL) [12,13]. The BCR-ABL1 translocations are considered to be prognostic of poorer outcomes in the context of patients diagnosed with Mixed Phenotype Acute Leukemia (MPAL) [12]. However, a number of individual studies indicate that Ph+ MPAL patients can be treated successfully with tyrosine kinase inhibitors (TKI) such as Imatinab and second generation TKIs [14,15].

Acute Myeloid Leukemia with BCR-ABL1

This rare entity, accounting for <1% of AML and <1% of BCR-ABL1 positive acute and chronic leukemias, typically occurs in adults. AML with BCR-ABL1 is aggressive with poor response to traditional AML therapy or isolated tyrosine kinase (TK) therapy alone; TK therapy with subsequent allogeneic hematopoietic cell transplantation may improve survival [16].

Gene Overview

The ABL1 gene encodes a non-receptor tyrosine kinase that is ubiquitously expressed and involved in a large number of cellular processes (see "NCBI Gene). By far the most prevalent ABL1 alteration associated with cancer are the fusions of the ABL1 gene with a number of partners, but especially with the BCR gene in CML [1,2] and to a lesser extent in B-ALL and T-ALL. The head to tail arrangement of the BCR-ABL1 fusion gene results in an activated tyrosine kinase activity [6]. It appears that the N-terminal domain of BCR can cause oligomerization of the BCR-ABL1 protein product, thus activating the ABL1 tyrosine kinase domain of the fusion protein [6,10,11]. The ABL1 and ABL2 genes encode tyrosine kinases which share overlapping physiological roles, and ABL2 somatic or amplification mutations are more common than similar mutations in ABL1 [6].

See the "BCR gene" for additional details of the BCR-ABL1 gene fusion.

Common Alteration Types

By far the most common ABL1 alteration associated with cancer is the BCR-ABL1 fusion as described above in CML and ALL.

A number of other gene fusion partners have been identified with ABL1 that are linked to hematological cancers, but at a much smaller prevalence than BCR-ABL1.

• NUP214-ABL1 (associated with T-cell Acute Lymphoblastic Leukemia).

• ETV6-ABL1 (associated with Chronic Myeloid Leukemia, T-cell Acute Lymphoblastic Leukemia, B-cell Acute Lymphoblastic Leukemia and Acute Myeloid Leukemia), and EML (associated with T-cell Acute Lymphoblastic Leukemia).

Somatic mutations for ABL1 have been found in Lung Squamous Cell Carcinomas patients (2%), Uterine Corpus Endometrioid Carcinoma patients (3%) and in less than 1% of patients with Breast Invasive Carcinoma, Ovarian Serous Cystadenocarcinoma, and Lung Adenocarcinoma [6].

Resistance to tyrosine kinase inhibitors (e.g., Gleevec) are attributed to secondary mutations within the tyrosine kinase domain of ABL1, especially the "gatekeeper" T315I residue mutation [7,8].

Copy Number Loss	Copy Number Gain	LOH	Loss-of-Function Mutation	Gain-of-Function Mutation	Translocation/Fusion
				X	X

Internal Pages

Chronic Myeloid Leukemia

Acute Lymphoblastic Leukemia

Acute Myeloid Leukemia (AML) with BCR-ABL1

Mixed Phenotype Acute Leukemia (MPAL) with t(9;22)(q34.1;q11.2); BCR-ABL1

See the "BCR gene" for additional details of the BCR-ABL1 gene fusion.

External Links

ABL1 by Atlas of Genetics and Cytogenetics in Oncology and Haematology - detailed gene information

ABL1 by COSMIC - sequence information, expression, catalogue of mutations

ABL1 by CIViC - general knowledge and evidence-based variant specific information

ABL1 by St. Jude ProteinPaint mutational landscape and matched expression data.

ABL1 by Precision Medicine Knowledgebase (Weill Cornell) - manually vetted interpretations of variants and CNVs

ABL1 by Cancer Index - gene, pathway, publication information matched to cancer type

ABL1 by OncoKB - mutational landscape, mutation effect, variant classification

ABL1 by My Cancer Genome - brief gene overview

ABL1 by UniProt - protein and molecular structure and function

ABL1 by Pfam - gene and protein structure and function information

ABL1 by GeneCards - general gene information and summaries

ABL1 by NCBI Gene - general gene information

ABL1 by OMIM - compendium of human genes and genetic phenotypes

ABL1 by LOVD(3) - Leiden Open Variation Database

ABL1 by TICdb - database of Translocation breakpoints In Cancer

References

1. Drucker BJ, et al., (2001). Activity of a specific inhibitor of the BCR-ABL tyrosine kinase in the blast crisis of chronic myeloid leukemia and acute lymphoblastic leukemia with the Philadelphia chromosome. NEJM 344:1038-1042. PMID 11287973. DOI: 10.1056/NEJM200104053441402.

2. Faderl S, et al., (1999). The biology of chronic myeloid leukemia. NEJM 341:164-172, PMID 10403855. DOI: 10.1056/NEJM199907153410306.

3. Wong S and Witte ON, (2004). The BCR-ABL story: bench to bedside and back. Annu Rev Immunol 22:247-306, PMID 15032571. DOI: 10.1146/annurev.immunol.22.012703.104753.

4. Soverini S, et al., (2014). Drug resistance and BCR-ABL kinase domain mutations in Philadelphia chromosome-positive acute lymphoblastic leukemia from the imatinib to the second-generation tyrosine kinase inhibitor era: The main changes are in the type of mutations, but not in the frequency of mutation involvement. Cancer 120:1002-1009, PMID 24382642. DOI: 10.1002/cncr.28522.

5. Drucker BJ, et al., (2001). Efficacy and safety of a specific inhibitor of the BCR-ABL tyrosine kinase in chronic myeloid leukemia. New England Journal of Medicine 344:1031–1037, PMID 11287972. DOI: 10.1056/NEJM200104053441401.

6. Greuber EK, et al., (2013). Role of ABL family kinases in cancer: from leukaemia to solid tumours. Nat Rev Cancer 13:559–571, PMID 23842646. DOIi: 10.1038/nrc3563.

7. Quintás-Cardama A and Cortes J, (2008). Therapeutic Options Against BCR-ABL1 T315I-Positive Chronic Myelogenous Leukemia. Clinical Cancer Research 14:4392-4399, PMID 18628453. DOI: 10.1158/1078-0432.CCR-08-0117.

8. Redaelli S, et al., (2009). Activity of bosutinib, dasatinib, and nilotinib against 18 imatinib-resistant BCR/ABL mutants. J Clin Oncol 27:469-471, PMID 19075254. DOI: 10.1200/JCO.2008.19.8853.

9. Diekmann D, et al., (1991). Bcr encodes a GTPase-activating protein for p21rac. Nature 35:400-402, PMID 1903516. DOI: 10.1038/351400a0.

10. McWhirter JR and Wang JY, (1991). Activation of tyrosinase kinase and microfilament-binding functions of c-abl by bcr sequences in bcr/abl fusion proteins. Mol Cell Biol 11:1553-1565, PMID 1705008.

11. Muller AJ, et al., (1991). BCR first exon sequences specifically activate the BCR/ABL tyrosine kinase oncogene of Philadelphia chromosome-positive human leukemias. Mol Cell Biol 11:1785-1792, PMID 2005881.

12. Charles NJ and, Boyer DF. (2017). Mixed-Phenotype Acute Leukemia: Diagnostic Criteria and Pitfalls. Arch Pathol Lab Med 141:1462-1468. PMID 29072953. doi: 10.5858/arpa.2017-0218-RA.

13. Manola KN, (2013). Cytogenetic abnormalities in acute leukaemia of ambiguous lineage: an overview. Br J Haematol 163:24-39. PMID 23888868. doi: 10.1111/bjh.12484.

14. Wolach O and Stone RM, (2014). How I treat mixed-phenotype acute leukemia. Blood 125:2477-2485. PMID 25605373. DOI: 10.1182/blood-2014-10-551465.

15. Kawajiri C, et al., (2014). Successful treatment of Philadelphia chromosome-positive mixed phenotype acute leukemia by appropriate alternation of second-generation tyrosine kinase inhibitors according to BCR-ABL1 mutation status. Blood 99:513-518. PMID 24532437. DOI: 10.1007/s12185-014-1531-0.

16. Arber DA, et al., (2017). Acute myeloid leukaemia with recurrent genetic abnormalities, in World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues, Revised 4th edition. Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J, Arber DA, Hasserjian RP, Le Beau MM, Orazi A, and Siebert R, Editors. Revised 4th Edition. IARC Press: Lyon, France, p140.

Notes

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