Saturday, October 08, 2022

Enzyme Inhibition in Neutrophils Halts Cancer Progression and Metastasis

Good news! Cancer is history (soon)! This new approach seems to work across several different cancer types.

"Researchers ... have uncovered a novel mechanism by which protein arginine deiminase 4 (PAD4) in neutrophils promotes cancer progression. The paper also found that inhibition of this function of PAD4 reduces primary tumor growth and metastasis and enhances checkpoint inhibitor treatments. Jubilant Therapeutics Inc. is developing a novel small molecule PAD4 inhibitor that directly targets this mechanism. ...
"Tumor-associated neutrophils have long been implicated in cancer progression. Understanding the mechanisms by which these cells promote tumor growth and metastatic spread is critically important for the development of new treatments,”...
Both genetic deletion of PAD4 and pharmacological inhibition of PAD4 ... dramatically down-regulated chemokine CXCR2, reduced immune suppressive polymorphonuclear myeloid derived suppressor cells (PMN-MDSCs) at tumor and metastatic sites, activated T cells, and synergized with immune checkpoint blockade. 
All results point to a potent anti-tumor effect of PAD4 inhibition to target PMN-MDSCs in the tumor microenvironment. ...
“We are developing several highly selective oral, small molecule PAD4 inhibitors, with the goal of bringing this novel mechanism to the clinic as potential therapeutics for tumor metastasis in colorectal and pancreatic cancers, patients with liver metastasis as well as for both acute and chronic autoimmune/inflammatory diseases.”"

From the abstract:
"Neutrophils are closely involved in the regulation of tumor progression and formation of premetastatic niches. However, the mechanisms of their involvement and therapeutic regulation of these processes remain elusive. Here, we report a critical role of neutrophil peptidylarginine deiminase 4 (PAD4) in neutrophil migration in cancer. In several transplantable and genetically engineered mouse models, tumor growth was accompanied by significantly elevated enzymatic activity of neutrophil PAD4. Targeted deletion of PAD4 in neutrophils markedly decreased the intratumoral abundance of neutrophils and led to delayed growth of primary tumors and dramatically reduced lung metastases. PAD4-mediated neutrophil accumulation by regulating the expression of the major chemokine receptor CXCR2. PAD4 expression and activity as well as CXCR2 expression were significantly upregulated in neutrophils from patients with lung and colon cancers compared with healthy donors, and PAD4 and CXCR2 expression were positively correlated in neutrophils from patients with cancer. In tumor-bearing mice, pharmacologic inhibition of PAD4 with the novel PAD4 isoform-selective small molecule inhibitor JBI-589 resulted in reduced CXCR2 expression and blocked neutrophil chemotaxis. In mouse tumor models, targeted deletion of PAD4 in neutrophils or pharmacologic inhibition of PAD4 with JBI-589 reduced both primary tumor growth and lung metastases and substantially enhanced the effect of immune checkpoint inhibitors. Taken together, these results suggest a therapeutic potential of targeting PAD4 in cancer.
Significance:
PAD4 regulates tumor progression by promoting neutrophil migration and can be targeted with a small molecule inhibitor to suppress tumor growth and metastasis and increase efficacy of immune checkpoint blockade therapy. ..."

The Wistar Institute and Jubilant Therapeutics Inc. Find PAD4 Inhibition in Neutrophils Halts Cancer Progression and Metastasis 

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