Phenotypically Screened Carbon Nanoparticles for Enhanced Combinatorial Therapy in Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is a highly aggressive type of breast cancer with high resistance to current standard therapies. We demonstrate that phenotypically stratified carbon nanoparticle is highly effective in delivering a novel combinatorial triple drug formulation for synergistic regression of TNBC in vitro and in vivo.

The combinatorial formulation is comprised of repurposed inhibitors of STAT3 (nifuroxazide), topoisomerase-II-activation-pathway (amonafide) and NFκb (pentoxifylline). Synergistic effect of drug combination was established in a panel of TNBC-lines comprising mesenchymal-stem-like, mesenchymal and basal-like cells along with non-TNBC-cells. The delivery of combinatorial drug formulation was achieved using a phenotypically screened carbon nanoparticles for TNBC cell lines.

Results indicated a remarkable five-fold improvement (IC50-6.75 µM) from the parent drugs with a combinatorial index <1 in majority of the TNBC cells. Multi-compartmental carbon nanoparticles were then parametrically assessed based on size, charge (positive/negative/neutral) and chemistry (functionalities) to study their likelihood of crossing endocytic barriers from phenotypical standpoint in TNBC lines. Interestingly, a combination of clathrin mediated, energy and dynamin dependent pathways were predominant for sulfonated nanoparticles, whereas pristine and phospholipid particles followed all the investigated endocytic pathways.

An exactitude 'omics' approach helps to predict that phospholipid encapsulated-particles will predominantly accumulate in TNBC comprising the drug-'cocktail'. We investigated the protein expression effects inducing synergistic effect and simultaneously suppressing drug resistance through distinct mechanisms of action.