A causal link from ALK to hexokinase II overexpression and hyperactive glycolysis in EML4-ALK-positive lung cancer

Abstract

A high rate of aerobic glycolysis is a hallmark of malignant transformation. Accumulating evidence suggests that diverse regulatory mechanisms mediate this cancer-associated metabolic change seen in a wide spectrum of cancer. The echinoderm microtubule associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion protein is found in approximately 3-7% of non-small cell lung carcinomas (NSCLC). Molecular evidence and therapeutic effectiveness of FDA-approved ALK inhibitors indicated that EML4-ALK is a driving factor of lung tumorigenesis. A recent clinical study showed that NSCLC harboring EML4-ALK rearrangements displayed higher glucose metabolism compared to EML4-ALK-negative NSCLC. In the current work, we presented evidence that EML4-ALK is coupled to overexpression of hexokinase II (HK2), one of the rate-limiting enzymes of the glycolytic pathway. The link from EML4-ALK to HK2 upregulation is essential for a high rate of glycolysis and proliferation of EML4-ALK-rearranged NSCLC cells. We identified hypoxia-inducible factor 1α (HIF1α) as a key transcription factor to drive HK2 gene expression in normoxia in these cells. EML4-ALK induced hypoxia-independent but glucose-dependent accumulation of HIF1α protein via both transcriptional activation of HIF1α mRNA and the PI3K-AKT pathway to enhance HIF1α protein synthesis. The EML4-ALK-mediated upregulation of HIF1α, HK2 and glycolytic metabolism was also highly active in vivo as demonstrated by FDG-PET imaging of xenografts grown from EML4-ALK-positive NSCLC cells. Our data reveal a novel EML4-ALK-HIF1α-HK2 cascade to enhance glucose metabolism in EML4-ALK-positive NSCLC.

The miR-125a/HK2 axis regulates cancer cell energy metabolism reprogramming in hepatocellular carcinoma

“…The three servers consistently predicted HK2, a key glycolytic gene in the Warburg effect 14, 22, 23 as the potential target of miR-125a. Thus, HK2 was chosen for further experimental validation.…”

The lignan manassantin is a potent and specific inhibitor of mitochondrial complex I and bioenergetic activity in mammals

“…During glycolysis, one molecule of water is released when 2-phosphoglycerate is converted to phosphoenolpyruvate. By labeling cells with [5-3 H]glucose, we were able to quantitate the glycolytic rate by measuring generation of [ 3 H]water (32,33). As demonstrated in Fig.…”

“…Several groups have previously reported that manassantin inhibits expression of HIF-1␣ (11)(12)(13)). Because HIF-1␣ is a master regulator of a myriad of glycolytic enzymes (32,34), one may anticipate that manassantin will down-regulate glycolysis as a result of its inhibition of HIF-1␣. To clarify the roles of manassantin in regulation of HIF-1␣ and in glycolysis, we revisited the effect of MNS-B on HIF-1␣.…”

“…Glycolysis in cultured cells was measured as we described (32,33). Briefly, cells were plated in 12-well plates and treated with vehicle or MNS-B for 16 h. [5-3 H]Glucose was added to a concentration of 2.5 Ci/ml and incubated for an additional 6 h. Hydrochloric acid was then added to the medium at a final concentration of 0.2 N to terminate all biological reactions.…”

Self-assembly of mitochondria-specific peptide amphiphiles amplifying lung cancer cell death through targeting the VDAC1–hexokinase-II complex

“…[22][23][24][25][26][27][28] Hexokinase-II (HK-II) is increasingly regarded as an attractive therapeutic target for cancer therapy based on its key role in glycolysis as a part of the cell energy metabolism. 29,30 The mitochondrial metabolism of cancer cells is deregulated, the glucose metabolism being enhanced and the mitochondrial oxidative phosphorylation reduced. HK-II is the enzyme that catalyses the phosphorylation of glucose, which is the rate-limiting first step of glycolysis (i.e.…”