Cancer-associated fibroblasts induce high mobility group box 1 and contribute to resistance to doxorubicin in breast cancer cells

Abstract

BackgroundCancer-associated fibroblasts and high mobility group box 1 (HMGB1) protein have been suggested to mediate cancer progression and chemotherapy resistance. The role of such fibroblasts in HMGB1 production in breast cancer is unclear. This study aimed to investigate the effects of cancer-associated fibroblasts on HMGB1 expression in breast cancer cells and its role in chemotherapeutic response.MethodsBreast cancer-associated fibroblasts (BCFs) and non-tumor-associated fibroblasts (NTFs) were isolated from human breast cancers or adjacent normal tissues and established as primary cultures in vitro. After confirmation of the activated status of these fibroblasts, conditioned-media (CM) were collected and applied to MDA-MB-231 human triple negative breast cancer cells. The levels of intracellular and extracellular HMGB1 were measured by real-time PCR and/or Western blot. The response of BCF-CM-pre-treated cancer cells to doxorubicin (Dox) was compared with those pre-treated with NTF-CM or control cultures. The effect of an HMGB1 neutralizing antibody on Dox resistance induced by extracellular HMGB1 from non-viable Dox-treated cancer cells or recombinant HMGB1 was also investigated.ResultsImmunocytochemical analysis revealed that BCFs and NTFs were alpha-smooth muscle actin (ASMA) positive and cytokeratin 19 (CK19) negative cells: a phenotype consistent with that of activated fibroblasts. We confirmed that the CM from BCFs (but not NTFs), could significantly induce breast cancer cell migration. Intracellular HMGB1 expression was induced in BCF-CM-treated breast cancer cells and also in Dox-treated cells. Extracellular HMGB1 was strongly expressed in the CM after Dox-induced MDA-MB-231 cell death and was higher in cells pre-treated with BCF-CM than NTF-CM. Pre-treatment of breast cancer cells with BCF-CM induced a degree of resistance to Dox in accordance with the increased level of secreted HMGB1. Recombinant HMGB1 was shown to increase Dox resistance and this was associated with evidence of autophagy. Anti-HMGB1 neutralizing antibody significantly reduced the effect of extracellular HMGB1 released from dying cancer cells or of recombinant HMGB1 on Dox resistance.ConclusionsThese findings highlight the potential of stromal fibroblasts to contribute to chemoresistance in breast cancer cells in part through fibroblast-induced HMGB1 production.

Taxotere-induced elevated expression of IL8 in carcinoma-associated fibroblasts of breast invasive ductal cancer

“…It was reported that IL-17A was overexpressed by colorectal CAFs in response to chemotherapy, with expression validated directly in patient-derived specimens without culture, suggesting that chemotherapy promotes tumor microenvironment remodeling to support the tumor cellular hierarchy through secreted factors (5). Amornsupak et al (17) reported that pre-treatment of breast cancer cells with breast cancer-associated fibroblasts induced a degree of resistance to doxorubicin in accordance with the increased level of secreted high mobility group box 1 (HMGB1), highlighting the potential of stromal fibroblasts to contribute to chemoresistance in breast cancer cells partially through fibroblast-induced HMGB1 production (17).…”

Metronomic chemotherapy remodel cancer‑associated fibroblasts to decrease chemoresistance of gastric cancer in nude mice

“…In vitro assays have also demonstrated that CAFs induce resistance to chemotherapy via secreting cytokines (16,22,23). Besides chemotherapy agents, inhibiting CAFs may also enhance the effects of bevacizumab (rhuMab VEGF, Avastin) even in bevacizumab-resistant GC cells (24), which is similar to the selective susceptibility of α-SMA-deficient vessels to bevacizumab (25).…”

“…Therefore, the stromal response in the MTD and LDM groups treated with 5-Fu or capecitabine was examined. CAFs were investigated on the basis of their proposed roles in supporting drug-resistance (16). As the characteristics of CAFs are rather distinctive in different tumor types and stages, without homogeneity, in order to compare the CAF evolution in GC following different patterns of chemotherapies, matched samples from identical xenografts of the control, MTD, and LDM groups were stained for the CAF marker α-SMA to reflect the difference (Fig.…”

“…The increased expression of CAFs in the tissue of patients receiving conventional therapy suggests the possibility of drug resistance (16). Thus, it was speculated that CAFs may rebuild the vessel in the microenvironment via the production of VEGF, leading to drug resistance following chemotherapy.…”

Predictive value of inflammatory indexes on the chemotherapeutic response in patients with unresectable lung cancer: A retrospective study

“…High levels of-tumor-associated macrophages (TAM), one of the most important types of inflammatory leukocytes (9), exhibit a crucial role in the chemotherapy-resistance of patients with lung cancer (10). Furthermore, cancer-associated fibroblasts have been demonstrated to contribute to the doxorubicin-resistance of breast cancer cells (11). Gene polymorphisms in DNA repair pathways and multi-drug resistance gene 1 (MDR1) could also contribute to the response of non-small cell lung cancer (NSCLC) to chemotherapy (12).…”