The Learning Blog

From PLoS ONE.

Italian researchers, in the Journal of Experimental and Clinical Cancer Research, investigated proton pump inhibitors, drugs used in the treatment of acid-related gastrointestinal disorders, as a new way of killing cancer cells.

In this report, the mechanism of destroying cancer cells focuses on the control of a pump that maintains the pH of cells. These so-called “V-ATPases” are pumps that maintain the neutral pH of the intracellular environment and the acidic extracellular environment. It is known that a low extracellular pH (an acidic environment) surrounding tumor or cancer cells contributes to invasion and spread of tumor cells by the secretion and activation of several proteases–enzymes that breakdown proteins. These proteases work as to develop new blood vessels supplying tumor cells the needed nutrients to grow rapidly–a phenomenon called “angiogenesis”.

Some studies tried various ways of neutralizing the above mechanism with only partial success. A 2005 study from China using a rat model pointed out that controlling the V-ATPases pump can prevent metastasis.

Proton pump inhibitors or PPIs such as omeprazole (Losec, Prilosec) works in an acidic environment. Using them in a highly acidic tumor environ have been shown in animals to be highly effective in controlling V-ATPases. In addition, using PPIs lower the risk of tumor-resistance to different anti-cancer drugs such as 5-fluorouracil, cisplatin, and doxorubicin.

The report concluded that PPIs can become a crucial addition to the armamentarium of oncologists due to their low-cost, low toxicity, and high efficacy, working best against malignant and drug-resistant tumors.

Click here for the study’s abstract.