Breast Cancer Drug Shrinks Mesothelioma Tumors in Mice

There is new evidence that a drug used to fight breast cancer may offer a new way to treat the intractable lung-related cancer, malignant pleural mesothelioma. Scientists at Rome’s Regina Elena National Cancer Institute have recently published some encouraging findings on the drug Aromasin (exemestane) in the journal Molecular Cancer.

Aromasin is designed to block the enzyme aromatase, which is critical for the synthesis of estrogen. For cancers that are sensitive to estrogen, such a breast cancer, reducing the amount of the hormone in the body by inhibiting aromatase has been shown to curb cancer growth.

Based on recent evidence that aromatase may also play a role in malignant mesothelioma, the Italian scientists tested the aromatase inhibitor Aromasin on mesothelioma cells in the lab and in live mice. “We show a significant reduction of cell proliferation, survival, migration and block of cells in S phase of cell cycle in mesothelioma cells upon exemestane (Aromasin) treatment,” reports lead author Barbara Nuvoli. Dr. Nuvoli notes that, as a breast cancer treatment, oral Aromasin is well-tolerated at 25 mg daily, has no major toxicity, and displays anti-inflammatory properties.

In their discussion of the findings, Nuvoli and her team note that Aromasin appears to work in part by inhibiting CD44, a cell surface glycoprotein involved in cell migration. Most importantly, according to the researchers, mice infected with human mesothelioma cells experienced “a significant decrease in tumor size” when they were treated with a combination of the standard mesothelioma drug pemetrexed (Alimta) and Aromasin. The combination proved to be even more effective than the most common mesothelioma chemotherapy combination, Alimta and cisplatin.

In fact, according to the team’s published report in Molecular Cancer the Alimta/Aromasin combination was so effective at shrinking mesothelioma tumors in mice that researchers could not obtain a large enough tumor sample to determine exactly how the treatment worked. They conclude that Aromasin might be a promising new agent for mesothelioma treatment and suggest the need for clinical trials. Because Aromasin has already been FDA approved for breast cancer, the researchers say they are hopeful that clinical trials in mesothelioma could happen quickly.

Source:

Nuvoli, B et al, “Exemestane blocks mesothelioma growth through downregulation of cAMP, pCREB and CD44 implicating new treatment option in patients affected by this disease”, March 21, 2014, Molecular Cancer, Epub ahead of print