Researchers found that a protein with anti-cancer activity, which is isolated from the bullfrog, may be a good treatment option for mesothelioma, including in standard-of-care chemotherapy-resistant cancers.
The protein, sialic acid-binding lectin (cSBL), has a toxic effect on cells and a preference to recognize, bind, and enter cancer cells rather than normal cells.
The study, “Synergistic anti-tumor effect of bullfrog sialic acid-binding lectin and pemetrexed in malignant mesothelioma,” was published in Oncotarget.
The authors compared the effect of cSBL on mesothelioma cells to the effect of standard-of-care chemotherapy for this type of cancer — a combination of Alimta (pemetrexed) and Platinol (cisplatin).
The bullfrog protein exhibited a higher cancer cell selection than the other two drugs and, when cSBL was given in combination with Alimta, it demonstrated a higher toxicity to mesothelioma cells than the normally used combination of Alimta and Platinol.
The research team explained that the cSBL-Alimta combo treatment obtains better results at eliminating cancer cells because of the double effect it produces in cells.
Alimta has a static effect on the cell’s life cycle because it does not allow cell division to occur and, therefore, stops the generation of new cancer cells.
The protein cSBL has a toxic effect on the cell because it stops protein formation through the degradation of the cell’s genetic material.
This study demonstrates the potential of this bullfrog protein with anti-cancer activity to “kill” mesothelioma cancer cells and presents cSBL as a possible future option for the treatment of mesothelioma patients.
“Pemetrexed + cSBL exhibited a strong synergistic effect that was comparable or even superior to the standard regimen of pemetrexed + cisplatin. We propose that the synergistic effect results from the combination of the cytostatic effect of pemetrexed and the cytotoxic effect of cSBL,” researchers wrote. “Therefore, cSBL has therapeutic potential for mesothelioma.”
Besides killing mesothelioma cells effectively, cSBL also shows a preference for cancer cells over normal cells more than other drugs, which translates into a less aggressive therapy for patients, causing less damage to healthy cells and fewer side effects.
When used together with Alimta, cSBL appears to be more efficient in neutralizing mesothelioma cancer cells. This means the amount of Alimta used in a chemotherapy dose with cSBL might be reduced and fewer healthy cells would be damaged by the drug.