Expression of Myoglobin in Human Cancers

Myoglobin plays an important role in muscle cells by both transporting oxygen and preventing cell damage by scavenging free radicals. Tumor cells often survive in hypoxic (low oxygen), high free radical environments, despite these stresses on tumor growth.

Flonta et al hypothesized that certain cancers may express myoglobin to survive the conditions associated with tumor growth. Indeed, human epithelial tumors, including breast, lung, ovary, and colon carcinomas, expressed high levels of myoglobin at early stages of development. In addition, myoglobin was induced in cell lines subjected to hypoxia, oxidative stress, and mitogenic stimulation. Myoglobin expression in carcinomas may therefore protect against the stresses of tumor growth.

Dr. Bardelli and colleagues postulate that "should myoglobin prove to play a causative role in tumor progression, … it is tempting to speculate that targeting one or more of its multiple functions by pharmacological agents or more advanced molecular tools could represent a novel therapeutic strategy in oncology."