Abstract 1433: CCL4 alters migration and induces the expression of alpha smooth muscle actin.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Prostate cancer is the most common diagnosed and the second leading cause of cancer deaths in men in the United States. Inflammation has been linked to the initiation and metastatic progression of prostate cancer. CCL4 was reported as a chemokine that is differentially expressed in patients that had recurrence of prostate cancer. The aim of this study is to determine the role of CCL4, CX3CL1 and IL-15 using prostate cancer cell lines and a mouse orthotopic xenograft model. PC3 prostate cancer cells (androgen independent) and 22RV1 prostate cancer cells (androgen dependant) were treated in vitro with CCL4 (0.001 and 0.1 ng/mL), CX3CL1 (0.0029 and 0.1 ng/mL) and IL15 (0.0013 and 0.1 ng/mL) and subjected to adhesion and invasion assays. SCID mice prostates were injected orthotopically with 250,000 PC3 or 22RV1 cells combined with each chemokine. Mice were injected bi-weekly with CCL4 (0.001 and 0.1 ng/mL), CX3CL1 (0.0029 and 0.1 ng/mL) and IL15 (0.0013 and 0.1 ng/mL). Tissues were collected after eight weeks (PC3) and four weeks (22RV1) of treatment. Tumor volumes were calculated and tissues were processed and embedded for immunohistochemistry analysis. In vitro studies indicated that PC3 cells treated with CCL4 had significantly increased migration when compared to control (P<0.05). However, PC3 cells treated with IL-15 showed an opposite effect having decreased invasion when compared to control (P<0.05). 22RV1 cells treated with CCL-4 showed significantly decreased adhesion when compared to control (P<0.05). In vivo studies showed that mice injected with 22RV1 cells and treated with CCL4 had significantly bigger tumors when compared to control mice after 4 weeks of tumor development. Immunohistochemical analysis revealed that CCL4 treatment increased the expression levels of alpha smooth muscle actin in 22RV1 tumors when compared to control tumors. Moreover, phospho-histone 3 expression was increased in 22RV1 tumors treated with CCL4 when compared to control tumors. This study showed that CCL4 altered migration and adhesion of PC3 cells and 22RV1 cells in vitro. CCL4 treatment induced tumor growth of 22RV1 cells in vivo using a SCID mouse orthotopic model. Interestingly tumors treated with CCL4 were associated with increased levels of alpha smooth muscle actin and proliferation. Our results indicate that CCL4 may promote tumor growth and metastasis in vivo by increasing proliferation, altering migration, and changing the expression levels of alpha smooth muscle actin. Citation Format: Krizia Rohena-Rivera, Maria M. Sanchez-Vazquez, Joseph Casillas-Gonzalez, Nemesis Merly, Mariela Perez-Quintana, Magaly Martinez-Ferrer. CCL4 alters migration and induces the expression of alpha smooth muscle actin. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1433. doi:10.1158/1538-7445.AM2013-1433