LMO2 (LIM domain only 2) is expressed in a subset of acute myeloid leukaemia and correlates with normal karyotype

Histopathology. 2014 Jan;64(2):226-33. doi: 10.1111/his.12242. Epub 2013 Nov 6.

Abstract

Aim: LMO2 is a transcription factor that plays a key role in haematopoiesis. Expression of LMO2 has been demonstrated in germinal centre B cells, various B cell lymphomas and T lymphoblastic lymphoma/leukaemia (T-ALL), but has not been studied extensively in acute myeloid leukaemia (AML).

Methods: We studied LMO2 expression by immunohistochemistry in biopsies from a cohort of AML patients (n = 196) and correlated it with established prognostic factors such as age, bone marrow morphology and cytogenetic findings.

Results: Forty per cent (79 of 196) of the samples from AML patients showed moderate/strong expression of LMO2 protein. LMO2 expression showed a significant positive correlation with normal cytogenetics (65% versus 24%, P < 0.0001) and a moderately negative correlation with complex karyotype [rs (98) = -0.218, P < 0.002]. AML associated with core binding factor [(t(8;21)/inv(16)/t(16;16)] had low LMO2 expression compared to diploid karyotype (29% versus 65%; P = 0.013). Expression of LMO2 protein exhibited an insignificant association with age (P = 0.197). Lower expression of LMO2 protein was noted in AML associated with myelodysplasia-related changes, compared to AML subtypes based on FAB classification (M0-M7) (21% versus 44%, P = 0.0187).

Conclusions: LMO2 is expressed in a subset of AML patients and is associated with normal karyotype, which is different from T-ALL, where specific translocation (11p13) mediates protein expression.

Keywords: LMO2; acute myeloid leukaemia; cytogenetics.

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Bone Marrow / pathology
  • Child
  • Child, Preschool
  • Cytogenetics
  • Female
  • Germinal Center / metabolism
  • Germinal Center / pathology
  • Humans
  • Karyotype
  • Karyotyping
  • LIM Domain Proteins / metabolism*
  • Leukemia, Myeloid, Acute / metabolism*
  • Leukemia, Myeloid, Acute / pathology
  • Male
  • Middle Aged
  • Proto-Oncogene Proteins / metabolism*
  • Young Adult

Substances

  • Adaptor Proteins, Signal Transducing
  • LIM Domain Proteins
  • LMO2 protein, human
  • Proto-Oncogene Proteins