Affiliations 

  • 1 Universiti Putra Malaysia
  • 2 Hospital Universiti Kebangsaan Malaysia
MyJurnal

Abstract

Introduction: The phenotype and genotype of cancer cells portray hallmarks of cancer which may
have clinical value. Cancer cell lines are ideal models to study and confirm these characteristics. We
previously established two subtracted cDNA libraries with differentially expressed genes from an
acute myeloid leukaemia patient with poor prognosis (PP) and good prognosis (GP). Objective: To
compare gene expression of the leukaemia associated genes with selected biological characteristics
in leukaemia cell lines and normal controls. Methodology: Expression of 28 PP genes associated
with early fetal/embryonic development, HOX-related genes, hematopoiesis and aerobic glycolysis/
hypoxia genes and 36 GP genes involved in oxidative phosphorylation, protein synthesis, chromatin
remodelling and cell motility were examined in B-lymphoid (BV173, Reh and RS4;11) and myeloid
(HL-60, K562) leukaemia cell lines after 72h in culture as well as peripheral blood mononuclear cells
from healthy controls (N=5) using semi-quantitative polymerase chain reaction (PCR) method. Cell
cycle profiles were analysed on flow cytometry while MTT cytotoxicity assay was used to determine
drug resistance to epirubicin. Results: Genes expressed significantly higher in B-lymphoid leukaemia
cell lines compared to healthy controls were mostly of the GP library i.e. oxidative phosphorylation
(3/10), protein synthesis (4/11), chromatin remodelling (3/3) and actin cytoskeleton genes (1/5). Only
two genes with significant difference were from the PP library. Cancer associated genes, HSPA9 and
PSPH (GP library) and BCAP31 (PP library) were significantly higher in the B-lymphoid leukemia cell
lines. No significant difference was observed between myeloid cell lines and healthy controls. This
may also be due heterogeneity of cell lines studied. PBMC from healthy controls were not in cell cycle.
G2/M profiles and growth curves showed B-lymphoid cells just reaching plateau after 72 hour culture
while myeloid cells were declining. IC50 values from cytotoxicity assay revealed myeloid cell lines had
an average 13-fold higher drug resistance to epirubicin compared to B-lymphoid cell lines. Only CCL1,
was expressed at least two-fold higher in myeloid compared to B-lymphoid cell lines. In contrast,
MTRNR2, EEF1A1, PTMA, HLA-DR, C6orf115, PBX3, ENPP4, SELL, and IL3Ra were expressed
more than 2-fold higher in B-lymphoid compared to myeloid cell lines studied here. Conclusion: Thus,
B-lymphoid leukaemia cell lines here exhibited active, proliferating characteristics closer to GP genes.
Higher expression of several genes in B-lymphoid compared to myeloid leukaemia cell lines may be
useful markers to study biological differences including drug resistance between lineages.