Abnormalities in Glucose Uptake and Metabolism in Imatinib-Resistant Human BCR-ABL–Positive Cells

Abstract

The development of imatinib resistance has become a significant therapeutic problem in which the etiology seems to be multifactorial and poorly understood. As of today, clinical criteria to predict the development of imatinib resistance in chronic myelogenous leukemia (CML), other than rebound of the myeloproliferation, are under development. However, there is evidence that the control of glucose-substrate flux is an important mechanism of the antiproliferative action of imatinib because imatinib-resistant gastrointestinal stromal KIT-positive tumors reveal highly elevated glucose uptake in radiologic images. We used nuclear magnetic resonance spectroscopy and gas chromatography mass spectrometry to assess 13 C glucose uptake and metabolism (glycolysis, TCA cycle, and nucleic acid ribose synthesis) during imatinib treatment in CML cell lines with different sensitivities to imatinib. Our results show that sensitive K562-s and LAMA84-s BCR-ABL-positive cells have decreased glucose uptake, decreased lactate production, and an improved oxidative TCA cycle following imatinib treatment. The resistant K562-r and LAMA84-r cells maintained a highly glycolytic metabolic phenotype with elevated glucose uptake and lactate production. In addition, oxidative synthesis of RNA ribose from 13 C-glucose via glucose-6-phosphate dehydrogenase was decreased, and RNA synthesis via the nonoxidative transketolase pathway was increased in imatinib-resistant cells. CML cells which exhibited a (oxidative/nonoxidative) flux ratio for nucleic acid ribose synthesis of >1 were sensitive to imatinib. The resistant K562-r and LAMA84-r exhibited a (oxidative/nonoxidative) flux ratio of <0.7. The changes in glucose uptake and metabolism were accompanied by intracellular translocation of GLUT-1 from the plasma membrane into the intracellular fraction in sensitive cells treated with imatinib, whereas GLUT-1 remained located at the plasma membrane in LAMA84-r and K562-r cells. The total protein load of GLUT-1 was unchanged among treated sensitive and resistant cell lines. In summary, elevated glucose uptake and nonoxidative glycolytic metabolic phenotype can be used as sensitive markers for early detection of imatinib resistance in BCR-ABL-positive cells.Chronic myelogenous leukemia (CML) is a myeloproliferative disorder associated with a t(9;22) chromosomal translocation which gives rise to the Philadelphia chromosome, resulting in the production of a BCR-ABL fusion protein (1, 2). A large portion of a proto-oncogene on chromosome 9, called ABL, is translocated to the BCR gene on chromosome 22 (2). The two gene segments are fused and ultimately produce a chimeric protein that is larger than the normal ABL protein (3).The development of novel targeted cancer-specific therapies is a major strategy in oncology, and the treatment of CML with imatinib mesylate (Gleevec or Glivec, formerly known as STI571) was the first successful proof of concept. Imatinib mesylate has revolutionized the way we treat CML its high level of activity, low toxicity...

Metabolic assessment of the action of targeted cancer therapeutics using magnetic resonance spectroscopy

“…Both the RAS-RAF-MEK-ERK1/2 and PI3K/Akt pathways are activated downstream of the chronic myeloid leukaemia BCR-ABL fusion protein. Inhibition of the BCR-ABL oncoprotein with imatinib in BCR-ABL-positive leukaemia cells resulted in decreased glucose uptake, lactate production and improved cellular energetics (Gottschalk et al, 2004), which were not recorded in their imatinib-resistant counterpart (Kominsky et al, 2009). These effects were coupled with translocation of the glucose transporter GLUT-1 from the plasma membrane to the cytoplasm in sensitive but not resistant lines, indicating an inhibition of glucose uptake following treatment with imatinib (Kominsky et al, 2009).…”

“…Inhibition of the BCR-ABL oncoprotein with imatinib in BCR-ABL-positive leukaemia cells resulted in decreased glucose uptake, lactate production and improved cellular energetics (Gottschalk et al, 2004), which were not recorded in their imatinib-resistant counterpart (Kominsky et al, 2009). These effects were coupled with translocation of the glucose transporter GLUT-1 from the plasma membrane to the cytoplasm in sensitive but not resistant lines, indicating an inhibition of glucose uptake following treatment with imatinib (Kominsky et al, 2009). As aberrant BCR promotes the expression of the proglycolytic protein C-MYC (Mahon et al, 2003), decreased glycolysis in response to imatinib treatment could be mediated through C-MYC suppression.…”

Exploiting tumor metabolism for non-invasive imaging of the therapeutic activity of molecularly targeted anticancer agents

“…However, and at least in the case of the inhibitors of BCR-ABL/platelet derived growth factor receptor (PDGFR) [73][74][75] and PI3K/mTOR, 59-61 similar anti-glycolytic effects were also observed in cells in vitro which were linked to downregulation of glucose metabolic enzymes (e.g., GLUT-1, LDH-A), thus ruling out the latter possibility.…”

HIF-1α and GLUT1 Gene Expression is Associated with Chemoresistance of Acute Myeloid Leukemia

“…In particular, the level of PKM2 showed an increasing tendency in both sera and tissues from CRC patients displaying no response to 5-FU-based chemotherapy, compared with that in complete or partial responders to 5-FU-based chemotherapy (Papageorgis et al, 2011). There is an evidence that the control of glucosesubstrate flux is an important mechanism of the antiproliferative action of imatinib because imatinib-resistant gastrointestinal stromal KIT-positive tumors reveal highly elevated glucose uptake in radiologic images (Kominsky et al, 2009). Similar results were also found in the imatinibresistant K562-r and LAMA84-r cells who maintained a highly glycolytic metabolic phenotype with elevated glucose uptake and lactate production (Kominsky et al, 2009).…”

“…There is an evidence that the control of glucosesubstrate flux is an important mechanism of the antiproliferative action of imatinib because imatinib-resistant gastrointestinal stromal KIT-positive tumors reveal highly elevated glucose uptake in radiologic images (Kominsky et al, 2009). Similar results were also found in the imatinibresistant K562-r and LAMA84-r cells who maintained a highly glycolytic metabolic phenotype with elevated glucose uptake and lactate production (Kominsky et al, 2009). The changes in glucose uptake and metabolism were accompanied by intracellular translocation of GLUT-1 from the plasma membrane into the intracellular fraction in sensitive cells treated with imatinib, whereas GLUT-1 remained located at the plasma membrane in LAMA84-r and K562-r cells (Kominsky et al, 2009).…”