CSF-1R as an inhibitor of apoptosis and promoter of proliferation, migration and invasion of canine mammary cancer cells

Abstract

BackgroundTumor-associated macrophages (TAMs) have high impact on the cancer development because they can facilitate matrix invasion, angiogenesis, and tumor cell motility. It gives cancer cells the capacity to invade normal tissues and metastasize. The signaling of colony-stimulating factor-1 receptor (CSF-1R) which is an important regulator of proliferation and differentiation of monocytes and macrophages regulates most of the tissue macrophages. However, CSF-1R is expressed also in breast epithelial tissue during some physiological stages i.g.: pregnancy and lactation. Its expression has been also detected in various cancers. Our previous study has showed the expression of CSF-1R in all examined canine mammary tumors. Moreover, it strongly correlated with grade of malignancy and ability to metastasis. This study was therefore designed to characterize the role of CSF-1R in canine mammary cancer cells proliferation, apoptosis, migration, and invasion. As far as we know, the study presented hereby is a pioneering experiment in this field of veterinary medicine.ResultsWe showed that csf-1r silencing significantly increased apoptosis (Annexin V test), decreased proliferation (measured as Ki67 expression) and decreased migration (“wound healing” assay) of canine mammary cancer cells. Treatment of these cells with CSF-1 caused opposite effect. Moreover, csf-1r knock-down changed growth characteristics of highly invasive cell lines on Matrigel matrix, and significantly decreased the ability of these cells to invade matrix. CSF-1 treatment increased invasion of cancer cells.ConclusionThe evidence of the expression and functional role of the CSF-1R in canine mammary cancer cells indicate that CSF-1R targeting may be a good therapeutic approach.

Expression and role of PGP, BCRP, MRP1 and MRP3 in multidrug resistance of canine mammary cancer cells

“…The RNAi gene silencing was highly successful (comparing to our previously published studies [19,21]), reaching even 100% of gene knock-down in case of bcrp in CMT-W2 cell line and mrp3 in case of CMT-U309 cell line. The results of gene knock-down were confirmed by the assay with rhodamine-123 efflux.…”

“…The siRNA transfection procedure used in canine mammary cancer cells was described in details in our previously published studies [19-21]. The cell density, transfection reagent toxicity and transfection efficacy were optimized according to the procedure described in our previous manuscript: [19].…”

Macrophage migration is controlled by Tribbles 1 through the interaction between C/EBPβ and TNF-α

“…Therefore Trib1 is potentially an important mediator of innate immunity. At some point, Trib1 expression in macrophages may provide a diagnosis marker in both human and veterinary medicine (Freitas Neto et al, 2013;Krol et al, 2013;Wiege et al, 2012).…”

miR‐1254 inhibits progression of glioma in vivo and in vitro by targeting CSF‐1

“…Besides, increased metastatic potential and a poor prognosis in breast cancer cells was indicated through the nuclear staining of CSF‐1 . In canine mammary cancer cells, CSF‐1R has been recognized as a promoter of migration, proliferation and invasion . Stalling CSF‐1R and CSF‐1 would limit metastasis and primary tumour growth by depleting TAMs (tumour‐associated macrophages) .…”