ACTREC Researchers Show Cancer Treatments May be Promoting its Spread

Standard cancer treatments can promote metastasis through the release of DNA- and protein-bearing particles from dying tumor cells, new study shows

MUMBAI, India, March 28, 2024 /PRNewswire/ -- Cancer spreads from its primary tumor to other parts of the body via blood or the lymphatic system in a process termed 'metastasis'. This usually represents an advanced stage in the disease's progression and tends to be fatal. Therefore, preventing metastasis remains a major goal in oncology.

In a step towards these efforts, Prof. Indraneel Mittra from the Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), India, has shed light on what causes metastasis.

Prof. Mittra's group focuses on cell-free chromatin particles (cfChPs)—small structures composed of DNA fragments and specialized proteins called histones—that are released when cells die. They have found that these particles, when released by dying cancer cells and reabsorbed by distant healthy cells, could be fundamental in the formation of new tumors.

Their findings, published in PLOS One result from experiments in mice grafted with human breast cancer cells (xenografts) to induce cancer. The researchers treated the primary tumors in these mice with chemotherapy, localized radiotherapy, or surgery and then searched for the presence of human DNA and human proteins in the mice's brains. "Using fluorescence microscopy techniques, we detected multiple co-localized signals of human DNA and eight human onco-proteins in mouse brain cells. Notably, the number of signals increased dramatically following either of the three types of treatment," remarks Prof. Mittra.

The researchers then tested whether blocking the effects of the cfChPs would change the results. As expected, the concentration of human DNA and oncoproteins in the mice's brain cells dropped significantly in mice that were treated with a cfChP-deactivating agent.

This study has important implications in reshaping cancer biology and treatment. Prof. Mittra concludes,"Future long-term experiments should explore whether cfChP-deactivating agents given concurrently with anti-cancer treatments could help prevent metastatic spread. When used as adjuncts to cancer treatment, these agents would have the added advantage of preventing some of the toxic side effects of chemotherapy and radiotherapy."

Reference
Title: Therapeutic interventions on human breast cancer xenografts promote systemic dissemination of oncogenes
Journal: PLOS One
DOI: 10.1371/journal.pone.0298042 

Media contact: 
Dr. Indraneel Mittra
Advance Centre for Treatment Research & Education in Cancer, Tata Memorial Centre (ACTREC)
Phone: +91 (022) 2740 5000/ 6873 5000 Extn-5136
Email: indraneel.mittra@gmail.com 
Website: http://www.actrec.gov.in/pi-webpages/DrIndraneelMittra/ 

Photo: https://mma.prnewswire.com/media/2371768/Circulating_cell_free_chromatin.jpg