Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The p53 tumor suppressor is found to be mutated and abundant in a wide variety of tumors. Within tumors showing rapid growth, the Type II isoform of hexokinase is also highly expressed to facilitate high rates of glucose catabolism, which in turn promote their rapid proliferation. We previously reported isolation of the proximal promoter of the Type II hexokinase gene from the highly glycolytic hepatoma AS-30D (Mathupala, S. P., Rempel, A., and Pedersen, P. L. (1995) J. Biol. Chem. 270, 16918-16925). Here, we show that a p53 protein, exhibiting two point mutations in its cDNA, is abundantly expressed in the AS-30D hepatoma. Co-expression studies showed that p53 overexpression significantly and reproducibly activated the Type II hexokinase promoter. Two functional p53 motifs were identified within this promoter by footprint and gel retardation analyses. Presence of functional p53 response elements on the Type II hexokinase promoter and the positive regulatory effect on the promoter by the mutant p53 indicates that in rapidly growing liver tumors, and perhaps in many other tumors as well, this highly abundant p53 protein plays a role in maintaining a high glycolytic rate. This is the first report of a possible link between loss of cell cycle control in rapidly growing cancer cells and their high glycolytic phenotype.
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PMID:Glucose catabolism in cancer cells. The type II hexokinase promoter contains functionally active response elements for the tumor suppressor p53. 927 38

Cancer cells with a high glycolytic rate have an advantage in tumor growth. Hepatocellular carcinoma (HCC) often exhibits an aberrant expression of glycolytic enzymes, particularly type II hexokinase (HKII) and aldolase B (ALDOB). This study examined the aberrant expression of HKII and ALDOB in 203 surgically resected HCCs. A dramatic down-regulation of ALDOB was found in 116 HCCs (57%), while 43% of HCCs maintained the expression. HKII mRNA was overexpressed in 70 (35%) primary HCCs. The ALDOB down-regulation and HKII overexpression correlated with high-grade (grade II-IV) HCC (all ps<0.0001), portal vein invasion (stage IIIB-IV) (ps<1x10(-6)), early tumor recurrence (ETR) (p<0.001 and p<0.01, respectively) and a lower 5-year survival (p=0.000001 and p=0.0062, respectively). Notably, in stage II HCC which had no vascular invasion, the ALDOB down-regulation was associated with ETR (p<0.05) and a lower 5-year survival (p=0.015). The down-regulation of ALDOB correlated with a high AFP (p=1x10(-8)), whereas the overexpression of HKII, which has two functional motifs for the mutant p53, correlated with the p53 mutation, p<0.01. The three factors (ALDOB down-regulation, HKII overexpression and p53 mutation) not only correlated with tumor progression, but also interacted with one another, leading to a more aggressive HCC with a portal vein invasion and various extent of intrahepatic metastasis by more than four-fold (ps<1x10(-6)) and frequent ETR by more than two-fold (ps<0.0001) compared with HCCs without the events. In conclusion, the aberrant expression of ALDOB and HKII is associated with advanced disease, ETR and poor prognosis, and ALDOB down-regulation in stage II HCC is a predictive marker of ETR and an unfavorable outcome.
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PMID:Aberrant expression of the glycolytic enzymes aldolase B and type II hexokinase in hepatocellular carcinoma are predictive markers for advanced stage, early recurrence and poor prognosis. 1835 95