Abstract: PD33-07
Sources of Funding: MOST103-2320-B-038-039-MY3, MOHW105-TDU-B-212-134001

Introduction

To evaluate the expression level of chemokine receptors in response to chemokines released by reactive stroma, quantitative PCR to evaluate the mRNA level of chemokine receptors was performed.

Methods

To check the expression level of CCRL2, we performed qRT-PCR and western blot analysis. Cell tracking assays were performed to analyze its role in chemoattraction. Proximity ligation assays were conducted to analyze the co-localization of CCRL2 and CCR5. To analyze the role of CCRL2 in regulation of cancer cell metastasis, we conducted in vivo analysis. Stromal cell overexpressed CCL5 were inoculated in renal capsule, followed by intra-peritoneal injection of prostate cancer cell overexpressed CCRL2 to determine the organ specific metastasis. To analyze the population of cells expression CCRL2, cell sorting assays was conducted.

Results

We noticed the significant increasing of CCRL2 (86-fold) in androgen insensitive prostate cancer cells. Knockdown of CCRL2 declined 75% of migration activities induced by CCL5, suggests CCRL2 involve in CCL5 induce cancer migratory activities. IHC analysis of CCRL2 in paired prostate cancer patients was performed and revealed increasing of CCRL2 expression in malignant prostate cancer locus, whereas no CCRL2 can be detected in the benign region of same patient. Proximity ligation assays (PLAs) of benign, high grade tumor and tissues collected from patients less than 5-year survive demonstrated the PLA signals only in the lethal progression on patients. In vivo xenograft mice model studies demonstrated the organ specific cancer metastasis can be enhanced after overexpressed CCRL2 in cancer cells. Cell sorting assays indicated that CCRL2 only expressed in less than 10% population of prostate cancer cells. Molecular analysis of CCRL2 demonstrated that CCRL2 regulated EZH2 expression in prostate cancer cells.

Conclusions

Our studies indicated the increased expression of CCRL2 play a central role in cancer cell migration induced by chemokine CCL5. CCL5, secreted by bone stromal cells after interaction with dormancy cancer cell, may induce directional migration and invasion of circulating cancer cells. Clinical analyses demonstrated increased of CCRL2 in malignant prostate cancer. Inhibition of these homing mechanisms might significantly decreased cancer cell metastatic activities of AIPC patients.

Funding

MOST103-2320-B-038-039-MY3, MOHW105-TDU-B-212-134001