A professor with University of California, Berkeley, is on a research team that paints lactate in a more sinister light -- as a key driver in the development and spread of cancer.

George Brooks, a renown researcher of the complex, often misunderstood molecule, spent two years working with Inigo San Millan, director of the sports performance department and physiology laboratory at the University ofColorado (CU) Sports Medicine and Performance Center at CU Boulder, on a paper recently published in the journal Carcinogenesis.

For decades, lactate has been studied largely in the context of exercise, painted as a nagging metabolic byproduct that accumulates in the tissues and blood during workouts, stiffening muscles and hindering performance.

As far back as 1923, German Nobel laureate Otto Warburg observed that cancer cells take in exponentially more sugar, or glucose, than normal cells. They inefficiently convert far less of it into energy, rather converting about 70 percent of it to lactate as a byproduct. The phenomenon, the first sign of a normal cell turning cancerous through abnormal cell metabolism, is known as the "Warburg effect."

With a heightened focus on genetics in recent decades, most researchers moved away from studying cancer metabolism, and the role of lactate became overshadowed, San Millan said.

The new study illuminates the role lactate plays in fueling angiogenesis, or the formation of new blood vessels in tumors; how it interferes with the body's immune response to cancer; and how it creates an acidic microenvironment, or the space outside the cancer cell, supportive of cancer metastases, or spread.