Importance of OPG, RANKL and TRAIL in breast tumor growth.

MARTINEZ LM. ; LABOVSKY V,; FERNANDEZ VALLONE VB.; OTAEGUI J; CHASSEING NA.

Orlando

Conferencia; Tumor Microenvironment Complexity: Emerging Roles in Cancer Therapy, Special Conference.; 2011

AACR

We studied OPG, RANKL, TRAIL, and their receptors (R) in human breast cancer cell (BCC) lines: MCF-7 and MDA-MB-231. Also, we measured these factors levels in the conditioned media (CM) of colony forming unit- fibroblast (CFU-F) and mesenchymal stem cells (MSC) cultures from bone marrow (BM) of 10 healthy volunteers (HV). Finally, we studied the effect of these CM over proliferation and apoptosis of BCC. Factors were quantified by ELISA in CM of BM and of BCC arrested and stimulated (10% FBS). Expression of them and their R in BCC were analyzed by IF and ICH. Proliferation by MTS assay: after arrest, BCC were incubated for 48hs with 50 or 100% of CM, with or not1.25% FBS. Apoptosis by FAC with Anexin-V and Tunel: after the arrest, BCC were incubated 24hs with 50% of CM in TRAIL presence or not. RANKL and TRAIL were low 31.25pg/ml in BM-CM but in previous studies we have found that 100% HV-MSC expressed membrane (m) RANKL.OPG (pg/ml): CFU-F=1,422+/-264 and MSC=1,269+/-161. 100%BCC expressed OPG, cytoplasmic RANKL, mRANKL, TRAIL, RANK and TRAIL-R1 and R4, 30-50% TRAIL-R2 and 40-55% TRAIL-R3. Results: significant difference in OPG values was found between both BCC (pg/ml/106cells): MCF-7=2,782+/-343; MDA-MB-231=1,081+/-204. RANKL and TRAIL were low 31.25 pg/ml in BCC-CM. No proliferative effect was observed by any of the treatments over BCC. When MDA-MB-231 cells were treated with CFU-F-CM in TRAIL presence, the % of BCC in apoptosis was lower vs control values (early and late apoptosis evaluated by Anexin: p=0.0015 and p=0.0339, and total apoptosis by Tunel: p=0.027).