All cancer drugs do not work

Washington, DC, July 02: All cancer drugs are not working on patients suffering from the deadly disease.

Otago University research findings shed light on the reasons for new immunologic checkpoint inhibitor therapies such as nivolumab and pembrolizumab, first approved in 2016 by the government. in New Zealand to treat metastatic melanoma, are not effective.

The new immunotherapeutic drugs announce a significant advance in the treatment of cancer. Although they may be effective for some melanoma patients, for others, the therapies do not work at all and most eventually become resistant to immunotherapy treatments.

One of the main components of the immune mechanism is a protein on the surface of the skin. cancerous cells called PD-L1 that can potentially be receptive or block immunotherapy.

The researchers were able to show that epigenetic modification – DNA modifications that do not directly alter the DNA sequence but change the frequency of use of a cell. specific genes – especially DNA methylation, influence if PD-L1 is expressed on the surface of cancer cells.

"Currently, there are no reliable biomarkers for predicting the benefits of immunotherapy in melanoma," said researcher Chris Jackson.

Jackson added that biomarkers help to select patients who are likely to benefit and who are not.

"Many groups in the world are s The discovery of an epigenetic marker by Otago seems very promising," he adds.

Jackson thinks the results will now have to be tested in people with melanoma being treated to see if this test can do it.

Another lead researcher, Aniruddha Chatterjee, says the findings suggest that epigenetic therapies could be used in clinical trials in combination with melanoma immunotherapy to treat patients. However, further trials would be needed before this becomes a possibility.

Due to the unavailability of robust biomarkers, it is difficult to predict a patient's response and also a relatively lesser understanding of resistance to immunologic treatment of melanoma.

Otago researchers believe that they have discovered a key piece of the puzzle

DNA methylation is an epigenetic mechanism that plays a key role in gene switching. "on" or "off" and helps determine cell function. "Our research provides evidence that this is the overall loss of DNA methylation that regulates the constitutive expression of the PD-L1 immune control point in melanoma," Chatterjee said. 19659004] The results have been announced by international research peers as "very innovative" and a major breakthrough in understanding the biology of melanoma.

The study appears in the journal iScience.