Acetazolamide, which is sold under the trade name Diamox and used to treat altitude sickness, is considered inexpensive to manufacture and easy to administer.
Acetazolamide is a studied to be a carbonic anhydrase inhibitor drug that can restore another drug's ability to eradicate tumor cells.
More specifically, acetazolamide when added to a drug called temozolomide (TMZ), it was seen to slow down the progression of glioblastoma in mouse models.
Acetazolamide enables TMZ to damage the DNA present in tumor cells in order to inhibit its growth.
Researchers discovered that glioblastoma patients with increased levels of a protein called BCL-3 (B cell CLL/lymphoma 3) were unresponsive to the effects exerted by the chemotherapeutic drug, TMZ. In particular, BCL-3 protects cancer cells from TMZ damage by activating a protective enzyme known as carbonic anhydrase II.
"We tested this combination treatment strategy in several animal models," Yamini said. “It cured some of them. Others had a 30 to 40 percent increase in survival time.”
By studying those pathways, carbonic anhydrase inhibitors were identified, such as acetazolamide, as a way to decrease the resistance to temozolomide.
Additionally, the authors believe that repurposing the use of acetazolamide along with temozolamide might be particularly effective for patients with tumors that have high BCL-3 expression.