BB-Cl-Amidine as a novel therapeutic for canine and feline mammary cancer via activation of the endoplasmic reticulum stress pathway

Melissa M Ledet,Rebecca Harman,Robyn Anderson,Aaron Muth,Paul R Thompson,Scott A Coonrod,Gerlinde R Van De Walle

doi:10.1186/s12885-018-4323-8

Melissa M Ledet, Rebecca Harman + Show 5 more

Open Access

https://doi.org/10.1186/s12885-018-4323-8

Copy DOI

Abstract

BackgroundMammary cancer is highly prevalent in dogs and cats and results in a poor prognosis due to critically lacking viable treatment options. Recent human and mouse studies have suggested that inhibiting peptidyl arginine deiminase enzymes (PAD) may be a novel breast cancer therapy. Based on the similarities between human breast cancer and mammary cancer in dogs and cats, we hypothesized that PAD inhibitors would also be an effective treatment for mammary cancer in these animals.MethodsCanine and feline mammary cancer cell lines were treated with BB-Cl-Amidine (BB-CLA) and evaluated for viability and tumorigenicity. Endoplasmic reticulum stress was tested by western blot, immunofluorescence, and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Canine and feline mammary cancer xenograft models were created using NOD scid gamma (NSG) mice, and were treated with BB-CLA for two weeks.ResultsWe found that BB-CLA reduced viability and tumorigenicity of canine and feline mammary cancer cell lines in vitro. Additionally, we demonstrated that BB-CLA activates the endoplasmic reticulum stress pathway in these cells by downregulating 78 kDa Glucose-regulated Protein (GRP78), a potential target in breast cancer for molecular therapy, and upregulating the downstream target gene DNA Damage Inducible Transcript 3 (DDIT3). Finally, we established a mouse xenograft model of both canine and feline mammary cancer in which we preliminarily tested the effects of BB-CLA in vivo.ConclusionWe propose that our established mouse xenograft models will be useful for the study of mammary cancer in dogs and cats, and furthermore, that BB-CLA has potential as a novel therapeutic for mammary cancer in these species.

Highlights

Mammary cancer is highly prevalent in dogs and cats and results in a poor prognosis due to critically lacking viable treatment options
BB-CLA selectively inhibits growth of canine and feline mammary tumor cells compared to normal mammary epithelial cells To start exploring the potential of peptidyl arginine deiminase enzyme (PAD) inhibitors as anti-cancer drugs to treat canine and feline mammary cancer, the tumoral cell lines REM134 and K12–72.1 were incubated with increasing doses of BB-Cl-Amidine (BBCLA) for 48 h and evaluated for viability using MTT assays
A dose-dependent decrease in cell viability was observed in both tumoral cell lines and reached significance starting at 1 μM for both REM134 and K12–72.1 (Fig. 1a)

Summary

Introduction

Mammary cancer is highly prevalent in dogs and cats and results in a poor prognosis due to critically lacking viable treatment options. Recent human and mouse studies have suggested that inhibiting peptidyl arginine deiminase enzymes (PAD) may be a novel breast cancer therapy. Based on the similarities between human breast cancer and mammary cancer in dogs and cats, we hypothesized that PAD inhibitors would be an effective treatment for mammary cancer in these animals. There are five basic classes of mammary cancer treatments in dogs and cats: surgery, radiation therapy, chemotherapy, hormone therapy and immunotherapy. Because the effectiveness of the latter four therapies is uncertain, surgery remains the treatment of choice [3]. Recent human and mouse studies have suggested that peptidyl arginine deiminase enzymes (PAD) could represent a novel target for epigenetic cancer therapy. The PAD family is made up of 5 (PAD1–4 and PAD6)

Methods

Results

Discussion

Conclusion