Researchers investigated the expression of CXCR5, a protein known to attract immune cells, in benign prostatic hyperplasia (BPH) and prostate cancer. Compared to a normal prostate, they found that CXCR5 was moderately increased in BPH but highly expressed in cancer tissue and cells. The results were published in a study entitled  “The Differential Expression and Function of the Inflammatory Chemokine Receptor CXCR5 in Benign Prostatic Hyperplasia and Prostate Cancer” in the International Journal of Medical Sciences.

CXCR5 is a receptor for chemokines, small molecules involved in the inflammatory response, expressed primarily by immune cells. Recent studies detected CXCR5 in tumors and also in prostate cancer cells, suggesting that the combination of CXCR5 with its ligand, CCXCL13, contributes to poor tumor prognosis. However, in prostate cancer and BPH, a benign condition in aging males, it remains unclear whether CXCR5 contribute to disease progression.

The researchers in this study investigated CXCR5 expression in tissue and cultured cells, finding that both cancer tissue and cells express high levels of CXCR5 when compared to BPH tissue and cells. Interestingly, upon in vitro culture, CXCR5 increased in BPH cells if they were allowed to interact with immune cells collected from the blood of volunteer patients. The team was able to show that inhibition of CXCR5 prevented  proliferation of cancer cells. “Chemokines are not only involved in the inflammatory response but also may participate in cancer tumorigenesis, progression and metastasis. Specific combinations of chemokine receptors may play an important role in tumor behavior,” explained the authors in their study.

In BPH subjects, although CXCR5 levels were observed as being low, their expression was up-regulated when BPH cells were incubated with inflammatory cells. Nevertheless, the role of CXCR5 and of other chemokine receptors in this benign malignancy require further confirmation in animal models.  “this study was mainly used in vitro approaches and thus additional in vivo studies are needed. Finally, this study focused on CXCR5, and hence the ligand, CXCL13, and the other chemokine receptors identified should be investigated in the future,” the authors concluded.