Abstract 3060: Role of curcumin in targeting cancer-associated fibroblasts and modulation of tumor microenvironment in dendritic cell-based immunotherapy

Abstract

Abstract INTRODUCTION: Cancer associated fibroblasts (CAFs), main component of tumor microenvironment (TME), modulate the recruitment and functions of tumor-associated immune cells by secreting various growth hormones, miRNAs and cytokines; thus having an important role in generation of immunosuppressive TME which is yet to be elucidated. Curcumin is known to have various properties including capability to modulate numerous target proteins including transcription factors, receptors, kinases, cytokines, enzymes and growth factors. Thus, aim of the study was to evaluate the effect of miRNAs and cytokines released by lung cancer patients’ derived CAFs and to assess immunomodulatory potential of curcumin on DC maturation by targeting these CAFs through modulating their TME. METHODOLOGY: CAFs were cultured from lung cancer patient derived tumor tissue biopsy and characterised using CAF-specific markers. Further, immature DCs (imDCs) were differentiated in presence of rGM-CSF and rIL-4 for 5-6 days. These imDCs were cultured in the presence of conditioned media derived from CAFs (CAFs-CM) as well as NFs (Normal Fibroblasts, NFs-CM) at day 6 for 48 hours to evaluate the effect of CAFs on DC maturation. Mature DCs (mDCs) were characterized by the presence of maturation markers CD80, CD83, CD86 and CTLA4 using qRT-PCR. Moreover, expression of miR-221, miR-222, miR-155, miR-142-3p and miR-146a was assessed to evaluate the role of epigenetic regulators on DC maturation. Cytokine profiling of CAFs-CM as well as CAFs-CM treated with curcumin was conducted. RESULTS: α-SMA+Vimentin+ cells were considered as CAFs. A significant upregulation of CD80, CD83 and CD86 was observed when cultured in the presence of NFs-CM while a remarkable downregulation of these markers was found when cultured in CAFs-CM. CTLA-4 was down regulated in NFs-CM as compared to CAFs-CM, suggesting the role of CAFs in generation of regulatory DCs. Amongst all miRNAs, miR-146a was shown to be up regulated dramatically in CAF-DCs (DCs cultured in CAFs-CM) as well as in CAFs-CM, suggesting the immunosuppressive role of miR-146a. Further, an increased expression of miR-146a was positively correlated with increased expression of anti-inflammatory cytokines like IL-6, IL-10, TGF-β and decreased expression of TNF-α (pro-inflammatory) in CM derived from CAF-DCs. Moreover, curcumin had the potential to convert regulatory DCs facilitated by CAFs into mDCs, which were characterized by high expression of co-stimulatory molecules, low expression of CTLA4, lower levels of immune suppressive cytokines production, lower levels of miR-146a. CONCLUSION: These findings provide insight into understanding the immunomodulatory role of curcumin in targeting CAFs and modulating the tumor microenvironment, thus enhancing antitumor immune response in DC based therapy. Citation Format: Sheefa Mirza, Nayan Jain, Rakesh Rawal. Role of curcumin in targeting cancer-associated fibroblasts and modulation of tumor microenvironment in dendritic cell-based immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3060. doi:10.1158/1538-7445.AM2017-3060