MOFs-Based Nanoagents Enable Sequential Damage to Cancer-Associated Fibroblast and Tumor Cells for Phototriggered Tumor Microenvironment Regulation.

A composite nanoagent capable of phototriggered tumor microenvironment (TME) regulation is developed based on copper (II) metal-organic frameworks (MOFs) with encapsulation of blebbistatin (Bb) and surface modification of fibroblast activation protein-αtargeted peptide (Tp). Tp enables active targeting of the nanoagents to cancer-associated fibroblast (CAF) while near-infrared light triggers Cu2+ -to-Cu+ photoreduction in MOFs, which brings about the collapse of MOFs and the release of Bb and Cu+ . Bb mediates photogeneration of hydroxyl radicals (•OH) and therefore inhibits extracellular matrix production by inducing CAF apoptosis, which facilitates the penetration of nanoagent to deep tumor tissue. The dual-channel generation of •OH based on Bb and the Cu+ species, via distinct mechanisms, synergistically reinforces oxidative stress in TME capable of inducing immunogenic cell death, which activates the antitumor immune response and therefore reverses the immunosuppressive TME. The synergistic antitumor phototherapy efficacy of such a type of nanoagent based on the abovementioned TME remodeling is unequivocally verified in a cell-derived tumor xenograft model.

Bruceine D suppresses CAF-promoted TNBC metastasis under TNF-α stimulation by inhibiting Notch1-Jagged1/NF-κB(p65) signaling.

BACKGROUND: Triple-negative breast cancer (TNBC) has a poor prognosis because of its high degree of malignancy and the lack of effective treatment options. Cancer-associated fibroblasts (CAFs) comprise the most abundant stromal cells in the tumor microenvironment (TME), leading to functional impairments and facilitating tumor metastasis. Excessive TNF-α further promotes cross-talk between different cells in TME. Therefore, there is an urgent need to develop more effective therapies and potential drugs that target the key factors that promote TNBC metastasis. PURPOSE: The study aimed to evaluate the efficacy of Bruceine D, an active compound derived from the Chinese herb Brucea javanica, in inhibiting metastasis and elucidate the underlying mechanism of action in TNBC. METHODS: In vitro, the clonogenic and the Transwell assays were used to assess the effects of Bruceine D on the proliferation, migration and invasion abilities of co-cultured CAFs and MDA-MB-231 (4T1) cells under TNF-α stimulation. TNF-α, IL-6, CXCL12, TGF-ß1, and MMP9 levels in the supernatant of co-cultured cells were determined using ELISA. Western blotting was utilized to detect the expression levels of proteins related to the Notch1-Jagged1/NF-κB(p65) pathway. In vivo, the anti-tumor growth and anti-metastatic effectiveness of Bruceine D was evaluated by determining tumor weight, number of metastatic lesions, and pathological changes in the tumor and lung/liver tissues. The inhibitory effect of Bruceine D on α-SMA+ CAFs activation and CAF-medicated extracellular matrix remodeling was accessed using immunohistochemistry, immunofluorescence, and Masson and Sirius Red staining. The expression levels of Notch1, Jagged1 and p-NF-κB(p65) proteins in the primary tumors were measured by immunohistochemistry and western blotting. RESULTS: In vitro, Bruceine D significantly inhibited the migration and invasion of co-cultured CAFs and MDA-MB-231 (4T1) cells under TNF-α stimulation, reduced the expression of tumor-promoting and matrix-remodeling cytokines secreted by CAFs, and hindered the mutual activation of Notch1-Jagged1 and NF-κB(p65). In vivo, Bruceine D significantly suppressed tumor growth and the formation of lung and liver metastases by decreasing TNF-α stimulated α-SMA+ CAFs activation, collagen fibers, MMPs production, and inhibited Notch1-Jagged1/NF-κB(p65) signaling in TNBC-bearing mice. CONCLUSION: Bruceine D effectively weakened the "tumor-CAF-inflammation" network by inhibiting the mutual activation of Notch1-Jagged1 and NF-κB(p65) and thereby suppressed TNBC metastasis. This study first explored that Bruceine D disrupted the cross-talk between CAFs and tumor cells under TNF-α stimulation to inhibit the metastasis of TNBC, and highlighted the potential of Bruceine D as therapeutic agent for suppressing tumor metastasis.

Shikonin reverses cancer-associated fibroblast-induced gemcitabine resistance in pancreatic cancer cells by suppressing monocarboxylate transporter 4-mediated reverse Warburg effect.

BACKGROUND: Gemcitabine is a first-line chemotherapeutic agent for pancreatic cancer (PC); however, most patients who receive adjuvant gemcitabine rapidly develop resistance and recurrence. Cancer-associated fibroblasts (CAFs) are a crucial component of the tumor stroma that contribute to gemcitabine-resistance. There is thus an urgent need to find a novel therapeutic strategy to improve the efficacy of gemcitabine in PC cells under CAF-stimulation. PURPOSE: To investigate if shikonin potentiates the therapeutic effects of gemcitabine in PC cells with CAF-induced drug resistance. METHODS: PC cell-stimulated fibroblasts or primary CAFs derived from PC tissue were co-cultured with PC cells to evaluate the ability of shikonin to improve the chemotherapeutic effects of gemcitabine in vitro and in vivo. Glucose uptake assay, ATP content analysis, lactate measurement, real-time PCR, immunofluorescence staining, western blot, and plasmid transfection were used to investigate the underlying mechanism. RESULTS: CAFs were innately resistant to gemcitabine, but shikonin suppressed the PC cell-induced transactivation and proliferation of CAFs, reversed CAF-induced resistance, and restored the therapeutic efficacy of gemcitabine in the co-culture system. In addition, CAFs underwent a reverse Warburg effect when co-cultured with PC cells, represented by enhanced aerobic glycolytic metabolism, while shikonin reduced aerobic glycolysis in CAFs by reducing their glucose uptake, ATP concentration, lactate production and secretion, and glycolytic protein expression. Regarding the mechanism underlying these sensitizing effects, shikonin suppressed monocarboxylate transporter 4 (MCT4) expression and cellular membrane translocation to inhibit aerobic glycolysis in CAFs. Overexpression of MCT4 accordingly reversed the inhibitory effects of shikonin on PC cell-induced transactivation and aerobic glycolysis in CAFs, and reduced its sensitizing effects. Furthermore, shikonin promoted the effects of gemcitabine in reducing the growth of tumors derived from PC cells and CAF co-inoculation in BALB/C mice, with no significant systemic toxicity. CONCLUSION: These results indicate that shikonin reduced MCT4 expression and activation, resulting in inhibition of aerobic glycolysis in CAFs and overcoming CAF-induced gemcitabine resistance in PC. Shikonin is a promising chemosensitizing phytochemical agent when used in combination with gemcitabine for PC treatment. The results suggest that disrupting the metabolic coupling between cancer cells and stromal cells might provide an attractive strategy for improving gemcitabine efficacy.

Neutralizing tumor-related inflammation and reprogramming of cancer-associated fibroblasts by Curcumin in breast cancer therapy.

Tumor-associated inflammation plays a vital role in cancer progression. Among the various stromal cells, cancer-associated fibroblasts are promising targets for cancer therapy. Several reports have indicated potent anti-inflammatory effects attributed to Curcumin. This study aimed to investigate whether inhibiting the inflammatory function of cancer-associated fibroblasts (CAFs) with Curcumin can restore anticancer immune responses. CAFs were isolated from breast cancer tissues, treated with Curcumin, and co-cultured with patients' PBMCs to evaluate gene expression and cytokine production alterations. Blood and breast tumor tissue samples were obtained from 12 breast cancer patients with stage II/III invasive ductal carcinoma. Fibroblast Activation Protein (FAP) + CAFs were extracted from tumor tissue, treated with 10 µM Curcumin, and co-cultured with corresponding PBMCs. The expression of smooth muscle actin-alpha (α-SMA), Cyclooxygenase-2(COX-2), production of PGE2, and immune cell cytokines were evaluated using Real-Time PCR and ELISA, respectively. Analyzes showed that treatment with Curcumin decreased the expression of genes α-SMA and COX-2 and the production of PGE2 in CAFs. In PBMCs co-cultured with Curcumin-treated CAFs, the expression of FoxP3 decreased along with the production of TGF-ß, IL-10, and IL-4. An increase in IFN-γ production was observed that followed by increased T-bet expression. According to our results, Curcumin could reprogram the pro-tumor phenotype of CAFs and increase the anti-tumor phenotype in PBMCs. Thus, CAFs, as a component of the tumor microenvironment, are a suitable target for combination immunotherapies of breast cancer.

Polysaccharides from Lentinus edodes prevent acquired drug resistance to docetaxel in prostate cancer cells by decreasing the TGF-ß1 secretion of cancer-associated fibroblasts.

Prostate cancer is one of the most prevalent lethal diseases among men globally. In the treatment of prostate cancer, the limited therapeutic efficacy of the standard non-hormonal systemic therapy docetaxel (DTX) represents an important challenge. Cancer-associated fibroblasts (CAFs) play a crucial role in resistance to therapy because of their prevalence and functional pleiotropy in tumor environments. Our previous research revealed that MPSSS, a novel polysaccharide extracted from Lentinus edodes, could significantly attenuate the immunosuppressive function of myeloid suppressor cells and CAFs. In this study, we investigated whether MPSSS could potentiate the efficacy of DTX against prostate cancer by inhibiting CAF-induced chemoresistance and elucidated its underlying mechanisms. The sensitivity of PC-3 prostate cancer cells cultured with conditioned medium derived from CAFs (CAF-CM) to DTX was assessed. The resistance effect induced by CAF-CM was abolished when CAFs were pretreated with MPSSS. Bioinformatic analysis of datasets from the Gene Expression Omnibus database revealed the activation of the transforming growth factor ß1 (TGF-ß1) signaling pathway in DTX-resistant cells. Based on this finding, we demonstrated that treatment with the TGF-ß1 receptor inhibitor SB525334 reversed DTX resistance in CAFs, suggesting that TGF-ß1 secreted by CAFs was a crucial intermediary in the development of DTX resistance in PC3 cells. Further research revealed that MPSSS decreases the secretion of TGF-ß1 by inhibiting the JAK2/STAT3 pathway via Toll-like receptor 4 in CAFs. Overall, MPSSS might be a potential adjuvant treatment for DTX resistance in prostate cancer.

Targeting MFAP5 in cancer-associated fibroblasts sensitizes pancreatic cancer to PD-L1-based immunochemotherapy via remodeling the matrix.

Highly desmoplastic and immunosuppressive tumor microenvironment (TME) in pancreatic ductal adenocarcinoma (PDAC) contributes to tumor progression and resistance to current therapies. Clues targeting the notorious stromal environment have offered hope for improving therapeutic response whereas the underlying mechanism remains unclear. Here, we find that prognostic microfibril associated protein 5 (MFAP5) is involved in activation of cancer-associated fibroblasts (CAFs). Inhibition of MFAP5highCAFs shows synergistic effect with gemcitabine-based chemotherapy and PD-L1-based immunotherapy. Mechanistically, MFAP5 deficiency in CAFs downregulates HAS2 and CXCL10 via MFAP5/RCN2/ERK/STAT1 axis, leading to angiogenesis, hyaluronic acid (HA) and collagens deposition reduction, cytotoxic T cells infiltration, and tumor cells apoptosis. Additionally, in vivo blockade of CXCL10 with AMG487 could partially reverse the pro-tumor effect from MFAP5 overexpression in CAFs and synergize with anti-PD-L1 antibody to enhance the immunotherapeutic effect. Therefore, targeting MFAP5highCAFs might be a potential adjuvant therapy to enhance the immunochemotherapy effect in PDAC via remodeling the desmoplastic and immunosuppressive microenvironment.

Biejiajian pill inhibits progression of hepatocellular carcinoma by downregulating PDGFRß signaling in cancer-associated fibroblasts.

ETHNOPHARMACOLOGICAL RELEVANCE: Biejiajian pill (BJJP) is a canonical formula that is clinically used to treat chronic liver disease, especially to decrease the incidence of hepatocellular carcinoma (HCC). However, the mechanisms underlying the prevention of HCC progression by BJJP remain unclear. AIM OF THE STUDY: This study aimed to determine whether BJJP inhibits HCC progression by downregulating platelet-derived growth factor receptor beta (PDGFRß) signaling in cancer-associated fibroblasts (CAFs) in a mouse model of diethylnitrosamine (DEN)/carbon tetrachloride (CCl4)-induced HCC. MATERIALS AND METHODS: C57BL/6 male mice were intraperitoneally injected with DEN 2 weeks after birth, followed by repeated injections of CCl4 weekly from 6 weeks of age onwards, to recapitulate features of HCC. At week 14, BJJP was orally administered to mice. The effects of BJJP on HCC progression were evaluated using histology, immunohistochemistry, and serum biochemical marker levels. Transcriptome analysis, molecular docking, quantitative real-time PCR, and Western blot were used to study the genes targeted by BJJP and the associated signaling pathway. The effects of BJJP on PDGFRß signaling in CAFs and the underlying mechanism were demonstrated. RESULTS: BJJP treatment significantly suppressed carcinogenesis and cancer progression, and it ameliorated liver inflammation in mice with HCC. A total of 176 genes, including PDGFRß, were significantly downregulated after BJJP treatment and five components of BJJP with high binding affinity to PDGFRß were identified. BJJP inhibited the phosphorylation of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), and glycogen synthase kinase 3 beta (GSK3ß) by suppressing PDGFRß expression in CAFs, and it also downregulated the expression of the downstream proteins hepatocyte growth factor (HGF) and vascular endothelial growth factor A (VEGF-A). Furthermore, BJJP-containing serum consistently reduced PDGFRß, HGF, and VEGF-A expression levels in HSC-derived CAFs in vitro. Importantly, PDGF-BB induced PDGFRß activation in CAFs and both BJJP and sunitinib (a kinase inhibitor) inhibited PDGF-BB/PDGFRß signaling. CONCLUSION: BJJP inhibits the progression of HCC through suppressing VEGF-A and HGF expression in CAFs by downregulating PDGFRß signaling.

Calcipotriol abrogates cancer-associated fibroblast-derived IL-8-mediated oxaliplatin resistance in gastric cancer cells via blocking PI3K/Akt signaling.

Activation of vitamin D receptor (VDR) in cancer-associated fibroblasts (CAFs) has been implicated in hesitating tumor progression and chemoresistance of several human malignancies. Yet, the role of VDR in CAF-induced chemotherapy resistance of gastric cancer (GC) cells remains elusive. In this study we first conducted immunohistochemistry analysis on tissue microarrays including 88 pairs of GC and normal mucosa samples, and provided clinical evidence that VDR was mainly expressed in gastric mucous cells but almost invisible in CAFs, and VDR expression was negatively correlated with malignant clinical phenotype and advanced stages, low VDR expression confers to poor overall survival rate of patients with GC. In a co-culture system of primary CAFs and cancer cells, we showed that treatment of HGC-27 and AGS GC cells with VDR ligand calcipotriol (Cal, 500 nM) significantly inhibited CAF-induced oxaliplatin resistance. By using RNA-sequencing and Human Cytokine Antibody Array, we demonstrated that IL-8 secretion from CAFs induced oxaliplatin resistance via activating the PI3K/AKT pathway in GC, whereas Cal treatment greatly attenuated the tumor-supportive effect of CAF-derived IL-8 on GC cells. Taken together, this study verifies the specific localization of VDR in GC tissues and demonstrates that activation of VDR abrogates CAF-derived IL-8-mediated oxaliplatin resistance in GC via blocking PI3K/Akt signaling, suggesting vitamin D supplementation as a potential strategy of enhancing the anti-tumor effect of chemotherapy in GC.

Inclusion of cancer-associated fibroblasts in drug screening assays to evaluate pancreatic cancer resistance to therapeutic drugs.

Pancreatic ductal adenocarcinoma (PDAC) is characterised by a pro-inflammatory stroma and multi-faceted microenvironment that promotes and maintains tumorigenesis. However, the models used to test new and emerging therapies for PDAC have not increased in complexity to keep pace with our understanding of the human disease. Promising therapies that pass pre-clinical testing often fail in pancreatic cancer clinical trials. The objective of this study was to investigate whether changes in the drug-dosing regimen or the addition of cancer-associated fibroblasts (CAFs) to current existing models can impact the efficacy of chemotherapy drugs used in the clinic. Here, we reveal that gemcitabine and paclitaxel markedly reduce the viability of pancreatic cell lines, but not CAFs, when cultured in 2D. Following the use of an in vitro drug pulsing experiment, PDAC cell lines showed sensitivity to gemcitabine and paclitaxel. However, CAFs were less sensitive to pulsing with gemcitabine compared to their response to paclitaxel. We also identify that a 3D co-culture model of MIA PaCa-2 or PANC-1 with CAFs showed an increased chemoresistance to gemcitabine when compared to standard 2D mono-cultures a difference to paclitaxel which showed no measurable difference between the 2D and 3D models, suggesting a complex interaction between the drug in study and the cell type used. Changes to standard 2D mono-culture-based assays and implementation of 3D co-culture assays lend complexity to established models and could provide tools for identifying therapies that will match clinically the success observed with in vitro models, thereby aiding in the discovery of novel therapies.

Jianpi Jiedu Recipe inhibits colorectal cancer liver metastasis via regulating ITGBL1-rich extracellular vesicles mediated activation of cancer-associated fibroblasts.

BACKGROUND: Extracellular vesicles (EVs) contribute greatly to the formation of pre-metastatic niche and tumor metastasis. Our previous study has revealed that tumor-derived ITGBL1 (integrin beta- like 1)-rich EVs activate fibroblasts through the NF-κB signaling to promote colorectal cancer (CRC) metastasis. Targeting ITGBL1-loaded EVs may be a new and effective therapy for treating CRC metastasis. Simultaneously, our preliminary clinical trial has demonstrated that Jianpi Jiedu Recipe (JPJDR) was an ideal alternative traditional Chinese medicine for the prevention and treatment of CRC metastasis. However, the underlying mechanism of JPJDR in the prevention of CRC metastasis is not clear. In this study, we will investigate the regulatory effect of JPJDR on ITGBL1 levels in CRC-derived EVs, and to detect how JPJDR regulate ITGBL1-rich EVs mediated activation of fibroblasts to inhibit CRC metastasis. METHODS: EVs derived from CRC cells with/without JPJDR treatment were obtained by ultracentrifugation, following by characterization with electron microscopy, LM10 nanoparticle characterization system and western blot. The migration and growth of CRC cells were tested by transwell assay, wound healing assay and colony formation assay. The effect of JPJDR on the fibroblasts-activation associated inflammatory factors including IL-6, IL-8 and α-SMA was detected by real-time PCR. The levels of IL-6, IL-8 and α-SMA in the cell culture supernatant were detected by ELISA. The protein expressions of TNFAIP3, ITGBL1, p-NF-κB, IκBα and ß-actin were detected by western blot. Liver metastasis model in mice was established by injecting MC38 single cell suspension into the spleen of mice to observe the effect of JPJDR on CRC liver metastasis. Immunohistochemistry were applied to detect the expression of ITGBL1 and TNFAIP3 in the liver metastatic tissues. Tissue immunofluorescence detection was performed to observe the regulatory effect of JPJDR on the ITGBL1-NF-κB signaling pathway. Cancer-associated fibroblasts (CAFs) in the liver metastatic tissues were sorted and characterized by platelet-derived growth factor receptor ß (PDGFRß) with flow cytometry, following by the detection of inflammatory factors including IL-6, IL-8 and α-SMA using real-time PCR. RESULTS: JPJDR reduced the ITGBL1 levels in CRC cells-derived EVs. JPJDR inhibited the migration and growth of CRC cells via regulating ITGBL1-rich EVs mediated fibroblasts activity. Mechanically, JPJDR decreased fibroblasts activation by regulating ITGBL1-rich EVs mediated TNFAIP3-NF-κB signaling. Further in vivo experiments demonstrated that JPJDR reduced CRC liver metastasis by regulating ITGBL1-rich EVs secretion from CRC and blocked the fibroblasts activation by regulating ITGBL1-TNFAIP3- NF-κB signaling. CONCLUSION: Our research demonstrated that JPJDR preventd CRC liver metastasis via down-regulating CRC-derived ITGBL1-loaded EVs mediated activation of CAFs, providing the experimental evidence for the clinical application of JPJDR in the prevention and treatment of CRC metastasis. More importantly, our study confirmed the great benefits of therapeutic targeting the EVs-mediated metastasis and warranted future clinical validation.

The functional cross talk between cancer cells and cancer associated fibroblasts from a cancer mechanics perspective.

The function of biological tissues in health and disease is regulated at cellular level and is highly influenced by the physical microenvironment, through the interaction of forces between cells and ECM, which are perceived through mechanosensing pathways. In cancer, both chemical and physical signaling cascades and their interactions are involved during cell-cell and cell-ECM communications to meet requirements of tumor growth. Among stroma cells, cancer associated fibroblasts (CAFs) play key role in tumor growth and pave the way for cancer cells to initiate metastasis and invasion to other tissues, and without recruitment of CAFs, the process of cancer invasion is dysfunctional. This is through an intense chemical and physical cross talks with tumor cells, and interactive remodeling of ECM. During such interaction CAFs apply traction forces and depending on the mechanical properties, deform ECM and in return receive physical signals from the micromechanical environment. Such interaction leads to ECM remodeling by manipulating ECM structure and its mechanical properties. The results are in form of deposition of extra fibers, stiffening, rearrangement and reorganization of fibrous structure, and degradation which are due to a complex secretion and expression of different markers triggered by mechanosensing of tumor cells, specially CAFs. Such events define cancer progress and invasion of cancer cells. A systemic knowledge of chemical and physical factors provides a holistic view of how cancer process and enhances the current treatment methods to provide more diversity among targets that involves tumor cells and ECM structure.

ITGB2-mediated metabolic switch in CAFs promotes OSCC proliferation by oxidation of NADH in mitochondrial oxidative phosphorylation system.

Objectives: Integrins, the coordinator of extracellular and intracellular signaling, are often found to be aberrant in tumors and can reshape the tumor microenvironment. Although previous studies showed that integrin beta 2 (ITGB2) is important for host defense, its expression profile and role in tumors, especially in cancer associated fibroblasts (CAFs) are still unknown. Methods: Immunofluorescence stain and fluorescence activated cell sorting were used to analyze the ITGB2 expression profile in oral squamous cell carcinoma (OSCC). RT-PCR and western blot were used to compare ITGB2 expression in normal fibroblasts (NFs) and cancer associated fibroblasts (CAFs). Clinical data and function-based experiments were used to investigate the promoting tumor growth ability of ITGB2 expressing CAFs. Enhanced glycolysis activity was identified by using bioinformatics analyses and GC/MS assays. MCT1 knockdown OSCC cell lines were constructed to explore the pro-proliferative mechanisms of ITGB2 expressing CAFs in multiple in vitro and in vivo assays. Results: We found that CAFs exhibited significantly higher ITGB2 expression than the matched NFs. In addition, higher ITGB2 expression in CAFs was correlated with higher TNM stages and more Ki67+ tumor cells, indicating its ability to promote OSCC proliferation. Further, co-culture assay demonstrated that ITGB2-mediated lactate release in CAFs promoted OSCC cell proliferation. Mechanically, ITGB2 regulated PI3K/AKT/mTOR pathways to enhance glycolysis activity in CAFs. Accordingly, lactate derived from ITGB2-expressing CAFs was absorbed and metabolized in OSCC to generate NADH, which was then oxidized in the mitochondrial oxidative phosphorylation system (OXPHOS) to produce ATP. Notably, inhibiting the OXPHOS system with metformin delayed the proliferative capacity of OSCC cells cultured in the ITGB2-expressing CAFs medium. Conclusions: Our study uncovered the ITGB2high pro-tumoral CAFs that activated the PI3K/AKT/mTOR axis to promote tumor proliferation in OSCC by NADH oxidation in the mitochondrial oxidative phosphorylation system.

Establishment of an in vitro 3D model for neuroblastoma enables preclinical investigation of combined tumor-stroma drug targeting.

The majority of anti-cancer therapies target the proliferating tumor cells, while the tumor stroma, principally unaffected, survives, and provide a niche for surviving tumor cells. Combining tumor cell and stroma-targeting therapies thus have a potential to improve patient outcome. The neuroblastoma stroma contains cancer-associated fibroblasts expressing microsomal prostaglandin E synthase-1 (mPGES-1). mPGES-1-derived prostaglandin E2 (PGE2 ) is known to promote tumor growth through increased proliferation and survival of tumor cells, immune suppression, angiogenesis, and therapy resistance, and we, therefore, hypothesize that mPGES-1 constitutes an interesting stromal target. Here, we aimed to develop a relevant in vitro model to study combination therapies. Co-culturing of neuroblastoma and fibroblast cells in 3D tumor spheroids mimic neuroblastoma tumors with regard to the cyclooxygenase/mPGES-1/PGE2 pathway. Using the spheroid model, we show that the inhibition of fibroblast-derived mPGES-1 enhanced the cytotoxic effect of doxorubicin and vincristine and significantly reduced tumor cell viability and spheroid growth. Cyclic treatment with vincristine in combination with an mPGES-1 inhibitor abrogated cell repopulation. Moreover, inhibition of mPGES-1 potentiated the cytotoxic effect of vincristine on established neuroblastoma allografts in mice. In conclusion, we established a 3D neuroblastoma model, highlighting the potential of combining stromal targeting of mPGES-1 with tumor cell targeting drugs like vincristine.

Developing a 3D B Cell Lymphoma Culture System to Model Antibody Therapy.

Diffuse large cell B cell lymphoma (DLBCL) accounts for approximately 30%-40% of all non-Hodgkin lymphoma (NHL) cases. Current first line DLBCL treatment results in long-term remission in more than 60% of cases. However, those patients with primary refractory disease or early relapse exhibit poor prognosis, highlighting a requirement for alternative therapies. Our aim was to develop a novel model of DLBCL that facilitates in vitro testing of current and novel therapies by replicating key components of the tumor microenvironment (TME) in a three-dimensional (3D) culture system that would enable primary DLBCL cell survival and study ex vivo. The TME is a complex ecosystem, comprising malignant and non-malignant cells, including cancer-associated fibroblasts (CAF) and tumor-associated macrophages (TAM) whose reciprocal crosstalk drives tumor initiation and growth while fostering an immunosuppressive milieu enabling its persistence. The requirement to recapitulate, at least to some degree, this complex, interactive network is exemplified by the rapid cell death of primary DLBCL cells removed from their TME and cultured alone in vitro. Building on previously described methodologies to generate lymphoid-like fibroblasts from adipocyte derived stem cells (ADSC), we confirmed lymphocytes, specifically B cells, interacted with this ADSC-derived stroma, in the presence or absence of monocyte-derived macrophages (MDM), in both two-dimensional (2D) cultures and a 3D collagen-based spheroid system. Furthermore, we demonstrated that DLBCL cells cultured in this system interact with its constituent components, resulting in their improved viability as compared to ex-vivo 2D monocultures. We then assessed the utility of this system as a platform to study therapeutics in the context of antibody-directed phagocytosis, using rituximab as a model immunotherapeutic antibody. Overall, we describe a novel 3D spheroid co-culture system comprising key components of the DLBCL TME with the potential to serve as a testbed for novel therapeutics, targeting key cellular constituents of the TME, such as CAF and/or TAM.

Melatonin Modulation of Radiation and Chemotherapeutics-induced Changes on Differentiation of Breast Fibroblasts.

Melatonin exerts oncostatic actions and sensitizes tumor cells to chemotherapeutics or radiation. In our study, we investigated the effects of docetaxel, vinorelbine, and radiation on human breast fibroblasts and its modulation by melatonin. Docetaxel or vinorelbine inhibits proliferation and stimulates the differentiation of breast preadipocytes, by increasing C/EBPα and PPARγ expression and by downregulating tumor necrosis factor α (TNFα), interleukin 6 (IL-6), and IL-11 expression. Radiation inhibits both proliferation and differentiation through the downregulation of C/EBPα and PPARγ and by stimulating TNFα expression. In addition, docetaxel and radiation decrease aromatase activity and expression by decreasing aromatase promoter II and cyclooxygenases 1 and 2 (COX-1 and COX-2) expression. Melatonin potentiates the stimulatory effect of docetaxel and vinorelbine on differentiation and their inhibitory effects on aromatase activity and expression, by increasing the stimulatory effect on C/EBPα and PPARγ expression and the downregulation of antiadipogenic cytokines and COX expression. Melatonin also counteracts the inhibitory effect of radiation on differentiation of preadipocytes, by increasing C/EBPα and PPARγ expression and by decreasing TNFα expression. Melatonin also potentiates the inhibitory effect exerted by radiation on aromatase activity and expression by increasing the downregulation of promoter II, and COX-1 and COX-2 expression. Our findings suggest that melatonin modulates regulatory effects induced by chemotherapeutic drugs or radiation on preadipocytes, which makes it a promising adjuvant for chemotherapy and radiotherapy sensibilization.

Photoimmunotherapy for cancer-associated fibroblasts targeting fibroblast activation protein in human esophageal squamous cell carcinoma.

Cancer-associated fibroblasts (CAFs) are strongly implicated in tumor progression, including in the processes of tumorigenesis, invasion, and metastasis. The targeting of CAFs using various therapeutic approaches is a novel treatment strategy; however, the efficacy of such therapies remains limited. Recently, near-infrared photoimmunotherapy (NIR-PIT), which is a novel targeted therapy employing a cell-specific mAb conjugated to a photosensitizer, has been introduced as a new type of phototherapy. In this study, we have developed a novel NIR-PIT technique to target CAFs, by focusing on fibroblast activation protein (FAP), and we evaluate the treatment efficacy in vitro and in vivo. Esophageal carcinoma cells exhibited enhanced activation of fibroblasts, with FAP over-expressed in the cytoplasm and on the cell surface. FAP-IR700-mediated PIT showed induced rapid cell death specifically for those cells in vitro and in vivo, without adverse effects. This novel therapy for CAFs, designed as local control phototherapy, was safe and showed a promising inhibitory effect on FAP+ CAFs. PIT targeting CAFs via the specific marker FAP may be a therapeutic option for CAFs in the tumor microenvironment in the future.

Elevated S100A8 protein expression in breast cancer cells and breast tumor stroma is prognostic of poor disease outcome.

PURPOSE: Elevated S100A8 expression has been observed in cancers of the bladder, esophagus, colon, ovary, and breast. S100A8 is expressed by breast cancer cells as well as by infiltrating immune and myeloid cells. Here we investigate the association of elevated S100A8 protein expression in breast cancer cells and in breast tumor stroma with survival outcomes in a cohort of breast cancer patients. PATIENTS AND METHODS: Tissue microarrays (TMA) were constructed from breast cancer specimens from 417 patients with stage I-III breast cancer treated at the University of Michigan Comprehensive Cancer Center between 2004 and 2006. Representative regions of non-necrotic tumor and distant normal tissue from each patient were used to construct the TMA. Automated quantitative immunofluorescence (AQUA) was used to measure S100A8 protein expression, and samples were scored for breast cancer cell and stromal S100A8 expression. S100A8 staining intensity was assessed as a continuous value and by exploratory dichotomous cutoffs. Associations between breast cancer cell and stromal S100A8 expression with disease-free survival and overall survival were determined using the Kaplan-Meier method and Cox proportional hazard models. RESULTS: High breast cancer cell S100A8 protein expression (as indicated by AQUA scores), as a continuous measure, was a significant prognostic factor for OS [univariable hazard ratio (HR) 1.24, 95% confidence interval (CI) 1.00-1.55, p = 0.05] in this patient cohort. Exploratory analyses identified optimal S100A8 AQUA score cutoffs within the breast cancer cell and stromal compartments that significantly separated survival curves for the complete cohort. Elevated breast cancer cell and stromal S100A8 expression, indicated by higher S100A8 AQUA scores, significantly associates with poorer breast cancer outcomes, regardless of estrogen receptor status. CONCLUSIONS: Elevated breast cancer cell and stromal S1008 protein expression are significant indicators of poorer outcomes in early stage breast cancer patients. Evaluation of S100A8 protein expression may provide additional prognostic information beyond traditional breast cancer prognostic biomarkers.

Pre-clinical evaluation of small molecule LOXL2 inhibitors in breast cancer.

Lysyl Oxidase-like 2 (LOXL2), a member of the lysyl oxidase family of amine oxidases is known to be important in normal tissue development and homeostasis, as well as the onset and progression of solid tumors. Here we tested the anti-tumor properties of two generations of novel small molecule LOXL2 inhibitor in the MDA-MB-231 human model of breast cancer. We confirmed a functional role for LOXL2 activity in the progression of primary breast cancer. Inhibition of LOXL2 activity inhibited the growth of primary tumors and reduced primary tumor angiogenesis. Dual inhibition of LOXL2 and LOX showed a greater effect and also led to a lower overall metastatic burden in the lung and liver. Our data provides the first evidence to support a role for LOXL2 specific small molecule inhibitors as a potential therapy in breast cancer.

Astragaloside IV inhibits pathological functions of gastric cancer-associated fibroblasts.

AIM: To investigate the inhibitory effect of astragaloside IV on the pathological functions of cancer-associated fibroblasts, and to explore the underlying mechanism. METHODS: Paired gastric normal fibroblast (GNF) and gastric cancer-associated fibroblast (GCAF) cultures were established from resected tissues. GCAFs were treated with vehicle control or different concentrations of astragaloside IV. Conditioned media were prepared from GNFs, GCAFs, control-treated GCAFs, and astragaloside IV-treated GCAFs, and used to culture BGC-823 human gastric cancer cells. Proliferation, migration and invasion capacities of BGC-823 cells were determined by MTT, wound healing, and Transwell invasion assays, respectively. The action mechanism of astragaloside IV was investigated by detecting the expression of microRNAs and the expression and secretion of the oncogenic factor, macrophage colony-stimulating factor (M-CSF), and the tumor suppressive factor, tissue inhibitor of metalloproteinase 2 (TIMP2), in different groups of GCAFs. The expression of the oncogenic pluripotency factors SOX2 and NANOG in BGC-823 cells cultured with different conditioned media was also examined. RESULTS: GCAFs displayed higher capacities to induce BGC-823 cell proliferation, migration, and invasion than GNFs (P < 0.01). Astragaloside IV treatment strongly inhibited the proliferation-, migration- and invasion-promoting capacities of GCAFs (P < 0.05 for 10 µmol/L, P < 0.01 for 20 µmol/L and 40 µmol/L). Compared with GNFs, GCAFs expressed a lower level of microRNA-214 (P < 0.01) and a higher level of microRNA-301a (P < 0.01). Astragaloside IV treatment significantly up-regulated microRNA-214 expression (P < 0.01) and down-regulated microRNA-301a expression (P < 0.01) in GCAFs. Reestablishing the microRNA expression balance subsequently suppressed M-CSF production (P < 0.01) and secretion (P < 0.05), and elevated TIMP2 production (P < 0.01) and secretion (P < 0.05). Consequently, the ability of GCAFs to increase SOX2 and NANOG expression in BGC-823 cells was abolished by astragaloside IV. CONCLUSION: Astragaloside IV can inhibit the pathological functions of GCAFs by correcting their dysregulation of microRNA expression, and it is promisingly a potent therapeutic agent regulating tumor microenvironment.

Polysaccharides from Polygonatum Inhibit the Proliferation of Prostate Cancer-Associated Fibroblasts.

Inhibition of cancer-associated broblasts (CAFs) may improve the efficacy of cancer therapy. Polysaccharide extracted from polygonatum can selectively inhibit the growth of prostate-CAFs (<.001) without inhibiting the growth of normal broblasts (NAFs). Polysaccharides from polygonatum stimulate autophagy of prostate-CAFs. 3-methyl-adenine(3-MA) is an autophagy inhibitor. 3-MA was added to prostate-CAFs with polysaccharide from polygonatum to determine whether autophagy plays an important role in the restrained effect. Finally, polysaccharide from polygonatum treatment significantly increased the activation of Beclin-1 and LC3, key autophagy proteins. Polysaccharides from polygonatum stimulate autophagy of prostate-CAFs and inhibits prostate-CAF growth, indicating that a novel anti-cancer strategy involves inhibiting the growth of prostate- CAFs.