Stimulation of brain hexokinase gene expression by recombinant brain insulin-like growth factor in C6 glial cells.

Glycolysis is essential for cerebral energy generation. Hence, expression and regulation of gene-encoding brain hexokinase (HK I), the exclusive brain glucose phosphorylating enzyme, can be a critical step in this process. The present study demonstrates the ability of recombinant brain insulin-like growth factor (BIGF, a closely related member of insulin superfamily) to stimulate HK I gene expression in a concentration- and time-dependent manner in C6 glial cells.

Expression of cell surface glycoprotein CD44 and integrins in breast cancers among Indian women.

Parsis, the sole surviving group of followers of Zoroaster who are settled in Bombay, have a fourfold higher incidence of breast cancer than the general population of Greater Bombay. CD44 expression was studied by immunohistochemistry in breast cancers of 50 non-Parsi and 35 Parsi women, 10 normal breast tissues, 10 proliferative lesions and 49 tissues adjoining a tumor mass. Alpha2 and beta1 integrins could be studied in only 42 malignant cases and five normal tissues.

Expression of two type II-like tumor hexokinase RNA transcripts in cancer cell lines.

To maintain an elevated glycolytic rate, cancerous or proliferating cells alter the expression pattern of rate limiting glycolytic enzymes. Since glucose phosphorylation is the first step in glycolysis, hexokinase (HK), the first rate limiting glycolytic enzyme, can play a key regulatory role in this process. A low-Km, mitochondrial type II-like tumor HK is described as the predominant form in hepatomas.

Insulin-like growth factor I induces tumor hexokinase RNA expression in cancer cells.

Increased glycolysis is a characteristic of cancer cells. Though less efficient in energy production, it ensures continuous supply of energy and phosphometabolites for biosynthesis enabling metastatic and less vascularized cancer cells to proliferate even under hypoxic conditions. Since hexokinase is the first rate limiting enzyme in the glycolytic pathway, elevated levels of Type II like hexokinase in tumors are of great significance in this context.