{'fraction_non_alphanumeric': 0.028970512157268494, 'fraction_numerical': 0.007242628039317123, 'mean_word_length': 5.3202614379084965, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Targeting Tumors' Energy Needs.

What’s old becomes new again: That adage appears to be true in tumor biology. Cancer researchers are beginning to focus on how tumors absorb and metabolize nutrients and how their metabolic processes differ from those of noncancerous cells. In 1924, Otto Warburg first observed that cancer cells process glucose differently from cells in healthy tissues (Biochem. Z. 1924;152:319). The energyproducing mitochondria in tumor cells appear to function just fine. So why cancer cells produce ATP, the cellular energy currency, through the less efficient pathway of aerobic glycolysis—converting glucose to lactic acid in the presence of oxygen—still is not clear. “The metabolism and utilization of nutrients of proliferating cells such as tumor cells is fundamentally different and potentially exploitable,” said Craig B. Thompson, M.D., who studies how signaling pathways regulate nutrient uptake at the Memorial Sloan Kettering Cancer Center in New York. “There are a lot of new ideas in the field, including targeting glucose metabolism.” What is starting to emerge is that oncogenes, genes that can cause cancer, are partly responsible for rewiring metabolic pathways. “Warburg posited that metabolism may be a way to target cancer cells, and that idea has been recently propelled by observations that oncogenes can be responsible, among other things, for changing tumor metabolic pathways through genetic rewiring,” said Susan M. Molineaux, Ph.D., CEO and founder of San Francisco–based Calithera Biosciences. Companies such as Calithera are now exploring whether using drug compounds to target the metabolic changes within tumors makes them vulnerable and whether these drugs could be effective treatments for cancer patients akin to therapies that target genetic driver mutations of tumor growth. “We’ve discovered that enzymes involved in metabolism, when mutated, can contribute to malignancy.”