Science News: Researchers discover that tumors inhibit the formation of metastasis

Science News: A study found why do metastases typically only manifest themselves after the primary tumour has been surgically removed? Researchers discovered a cancer cell messenger chemical that locally encourages the growth of the original tumor. One of the messenger’s two fragments that are broken up into the blood prevents metastasis. Mice with tumours that were given the metastasis-inhibiting fragment fared better than untreated animals.

ANGPLT4 is produced by cells of the primary tumor and locally promotes its growth. If the messenger substance is released into the bloodstream, it is cleaved. For reasons not yet fully understood, the n-fragment is found almost exclusively in serum. Many cancer patients could benefit from drugs that effectively suppress metastatic outgrowth. Some of these agents have already failed in clinical trials.

A team of researchers at Johns Hopkins University has identified a key player in the development of tumors from implanted breast cancer or melanoma cells. They found reduced tumor growth and metastasis for both types of tumors in mice missing CXCR2 signaling in myeloid cells.

An in-depth analysis of immune cells and chemokine factors in the tumors revealed surprises, Ann Richmond said.

Researchers at the University of Maryland have shown that mice lacking CXCR2 receptor expression in myeloid cells led to depletion of MDSCs and suppression of CD8+ T cell antitumor activity. They found positive correlations among B cell markers, CXCL11 and a CD8-T cell marker in association with increased survival among breast cancer and melanoma patients. Researchers are exploring whether this axis may be important in breast cancer prognosis.