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Chemotherapy May Strengthen Tumor Resistance, Growth

August 7, 2012

Connie K. Ho for redOrbit.com – Your Universe Online

90 percent. This is the percentage of solid cancer patients who have gradual resistance to chemotherapy, according to BBC News. Researchers recently revealed that chemotherapy, a treatment for cancer, could possibly damage healthy cells and trigger a protein that would strengthen tumor resistance and growth.

Chemotherapy is described as a treatment that can stop reproduction of fast-dividing cells and is given in various dosages. According to Yahoo News Canada, the investigators made the “completely unexpected” discovery while studying why cancer cells were defensive in the human body but easily eliminated in the lab. They were examining the impact of chemotherapy on healthy connective tissue, known as fibroblasts, of men who had developed prostate cancer and found “evidence of DNA damage” in the healthy cells following treatment. The findings of the study were recently featured in the journal Nature Medicine.

“Cancer cells inside the body live in a very complex environment or neighborhood,” lead scientist Dr. Peter Nelson, member of the Fred Hutchinson Cancer Research Center, told the Daily Mail. “Where the tumor cell resides and who its neighbors are influence its response and resistance to therapy.”

The findings showed that healthy cells affected by chemotherapy emitted 30 more times of WNT16B, a protein that increased cancer cell survival, than necessary.

“The increase in WNT16B was completely unexpected,” explained co-author Nelson of the Fred Hutchinson Cancer Research Center in an AFP article.

The scientists found that the protein was absorbed by tumor cells in nearby damaged cells.

“WNT16B, when secreted, would interact with nearby tumor cells and cause them to grow, invade, and importantly, resist subsequent therapy,” noted Nelson in the Yahoo Canada News article.

With chemotherapy treatments, tumors usually respond to the treatments but then regrow quickly and show continued resistances against chemotherapy.

“But this work confirms that healthy cells surrounding the tumor can also help the tumor to become resistant to treatment. The next step is to find ways to target these resistance mechanisms to help make chemotherapy more effective,” Professor Fran Balwill of Cancer Research UK mentioned in an article by the Daily Mail.

The findings also demonstrated that the rate of tumor cell reproduction increased between treatments.

“Our results indicate that damage responses in benign cells… may directly contribute to enhanced tumor growth kinetics,” wrote the team in a response to Yahoo Canada News.

Furthermore, the researchers compared their results with breast and ovarian cancer tumors and believe that there is the possibility for new cancer treatments to be developed. If researchers block the treatment response of the fibroblasts, they could possibly boost the effectiveness of chemotherapy.

“For example, an antibody to WNT16B, given with chemotherapy, may improve responses (kill more tumor cells),” commented Nelson in an email to Yahoo Canada News. “Alternatively, it may be possible to use smaller, less toxic doses of therapy.”

The results provided by the study align with other projects done on tumors.

“This work fits with other research showing that cancer treatments don’t just affect cancer cells, but can also target cells in and around tumors. Sometimes this can be good – for instance, chemotherapy can stimulate surrounding healthy immune cells to attack tumors,” commented Balkwill in a BBC article. “But this work confirms that healthy cells surrounding the tumor can also help the tumor to become resistant to treatment. The next step is to find ways to target these resistance mechanisms to help make chemotherapy more effective.”


Source: Connie K. Ho for redOrbit.com - Your Universe Online



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