BM-MSCs promote prostate cancer progression via the conversion of normal fibroblasts to cancer-associated fibroblasts

War or peace: Viruses and metastasis

Metastasis, the dissemination of malignant cells from a primary tumor to secondary sites, poses a catastrophic burden to cancer treatment and is the predominant cause of mortality in cancer patients. Metastasis as one of the main aspects of cancer progression could be strongly under the influence of viral infections. In fact, viruses have been central to modern cancer research and are associated with a great number of cancer cases. Viral-encoded elements are involved in modulating essential pathways or specific targets that are implicated in different stages of metastasis. Considering the continuous emergence of new viruses and the establishment of their contribution to cancer progression, the warfare between viruses and cancer appears to be endless. Here we aimed to review the critical mechanism and pathways involved in cancer metastasis and the influence of viral machinery and various routes that viruses adopt to manipulate those pathways for their benefit.

Effect of Bioactive Black Phosphorus Nanomaterials on Cancer-Associated Fibroblast Heterogeneity in Pancreatic Cancer

Tumor-stromal interactions and stromal heterogeneity in the tumor microenvironment are critical factors that influence the progression, metastasis, and chemoresistance of pancreatic ductal adenocarcinoma (PDAC). Here, we used spatial transcriptome technology to profile the gene expression landscape of primary PDAC and liver metastatic PDAC after bioactive black phosphorus nanomaterial (bioactive BP) treatment using a murine model of PDAC (LSL-KrasG12D/+; LSL-Trp53R172H/+; and Pdx-1-Cre mice). Bioinformatic and biochemical analyses showed that bioactive BP contributes to the tumor-stromal interplay by suppressing cancer-associated fibroblast (CAF) activation. Our results showed that bioactive BP contributes to CAF heterogeneity by decreasing the amount of inflammatory CAFs and myofibroblastic CAFs, two CAF subpopulations. Our study demonstrates the influence of bioactive BP on tumor-stromal interactions and CAF heterogeneity and suggests bioactive BP as a potential PDAC treatment.

Cancer-associated fibroblasts: heterogeneity and their role in the tumor immune response

In recent decades, many reports have been published on the composition and function of the tumor microenvironment (TME), among which cancer-associated fibroblasts (CAFs) have received much attention. CAFs have different degrees of heterogeneity in terms of their origin, phenotype, and function and can be divided into different subpopulations. These subgroups may play different roles in the occurrence and development of tumors. In addition, CAFs are closely associated with tumor immunity and have been found to regulate immune cell activity and to suppress the tumor immune response. In this review, we systematize the heterogeneity and characteristics of CAFs, discuss how specific CAF subgroups contribute to cancer progression by inducing an immunosuppressive microenvironment, and finally, we examine the future clinical applications of CAF subgroups.

Targeting the tumor microenvironment, a new therapeutic approach for prostate cancer

BACKGROUND

A growing number of studies have shown that in addition to adaptive immune cells such as CD8 + T cells and CD4 + T cells, various other cellular components within prostate cancer (PCa) tumor microenvironment (TME), mainly tumor-associated macrophages (TAMs), cancer-associated fibroblasts (CAFs) and myeloid-derived suppressor cells (MDSCs), have been increasingly recognized as important modulators of tumor progression and promising therapeutic targets.

OBJECTIVE

In this review, we aim to delineate the mechanisms by which TAMs, CAFs and MDSCs interact with PCa cells in the TME, summarize the therapeutic advancements targeting these cells and discuss potential new therapeutic avenues.

METHODS

We searched PubMed for relevant studies published through December 10 2023 on TAMs, CAFs and MDSCs in PCa.

RESULTS

TAMs, CAFs and MDSCs play a critical role in the tumorigenesis, progression, and metastasis of PCa. Moreover, they substantially mediate therapeutic resistance against conventional treatments including anti-androgen therapy, chemotherapy, and immunotherapy. Therapeutic interventions targeting these cellular components have demonstrated promising effects in preclinical models and several clinical trials for PCa, when administrated alone, or combined with other anti-cancer therapies. However, the lack of reliable biomarkers for patient selection and incomplete understanding of the mechanisms underlying the interactions between these cellular components and PCa cells hinder their clinical translation and utility.

CONCLUSION

New therapeutic strategies targeting TAMs, CAFs, and MDSCs in PCa hold promising prospects. Future research endeavors should focus on a more comprehensive exploration of the specific mechanisms by which these cells contribute to PCa, aiming to identify additional drug targets and conduct more clinical trials to validate the safety and efficacy of these treatment strategies.

Molecular imaging reveals the heterogeneous progression of tumor cells and tumor stroma: a practice of FDG PET and FAPI PET in diagnosing PSMA-negative bone metastases of progressive prostate cancer

Tumors are often with complex and heterogeneous biological processes, such as glycometabolism and fibrosis, which are the main biochemical pathways that determine therapeutic effects. Specifically, this study aims to assess the diagnosing performance of 18F-FDG and 68Ga-FAPI-04 PET for different stages of progressive bone metastases with PSMA-negative pathology. Bone metastatic mouse model of prostate cancer was constructed via intra-bone injection of PSMA-negative prostate cancer PC3 cells. Cellular uptakes of 18F-FDG and 68Ga-FAPI-04 were separately performed on PC3, NIH-3T3 (FAP-positive) and a mixture. 68Ga-PSMA-11, 18F-FDG and 68Ga-FAPI-04 PET/CT imaging were performed at 2, 4 weeks after tumor cell transplantation. Furthermore, PSMA and FAP expression in bone metastases were assessed by immunohistochemistry, and then compared with the imageological findings. On the cellular level, the independent tracer uptake on the basis of glycometabolism and fibrosis was observed. For animal imaging, 68Ga-PSMA-11 imaging showed weak or absent tracer uptake in PSMA-negative bone metastatic lesions. In contrast, 68Ga-FAPI-04 PET of bone metastases had a higher uptake and tumor-to-muscle (T/M) ratio than 18F-FDG PET that was relative steady during the observation, but T/M ratio of fibrosis gradually decreased with increasing tumor growth, which ranged from 5.11 ± 1.26 at 2 weeks to 3.54 ± 0.23 at 4 weeks, revealing the delayed formation of tumor stroma in rapid proliferation. In addition, PET imaging results were corroborated by immunohistochemical assessment. In conclusion, molecular imaging approach revealed the heterogeneous progression of tumor cells and tumor stroma of bone metastasis of prostate cancer, and further confirming the necessity of multi-molecular imaging in cancer imaging.

Mesenchymal stem cells and their extracellular vesicles in urological cancers: Prostate, bladder, and kidney

Mesenchymal stem cells (MSCs) are recognized for their remarkable ability to differentiate into multiple cell types. They are also known to possess properties that can fight cancer, leading to attempts to modify MSCs for use in anticancer treatments. However, MSCs have also been found to participate in pathways that promote tumor growth. Many studies have been conducted to explore the potential of MSCs for clinical applications, but the results have been inconclusive, possibly due to the diverse nature of MSC populations. Furthermore, the conflicting roles of MSCs in inhibiting tumors and promoting tumor growth hinder their adaptation to anticancer therapies. Antitumorigenic and protumorigenic properties of MSCs in urological cancers such as bladder, prostate, and renal are not as well established, and data comparing them are still limited. MSCs hold significant promise as a vehicle for delivering anticancer agents and suicide genes to tumors. Presently, numerous studies have concentrated on the products derived from MSCs, such as extracellular vesicles (EVs), as a form of cell-free therapy. This work aimed to review and discuss the current knowledge of MSCs and their EVs in urological cancer therapy.

Type VII Collagen Deficiency in the Oncogenesis of Cutaneous Squamous Cell Carcinoma in Dystrophic Epidermolysis Bullosa

Dystrophic epidermolysis bullosa is a rare genetic skin disorder caused by COL7A1 sequence variations that result in type VII collagen deficits and cutaneous and extracutaneous manifestations. One serious complication of dystrophic epidermolysis bullosa is cutaneous squamous cell carcinoma, a leading driver of morbidity and mortality, especially among patients with recessive dystrophic epidermolysis bullosa. Type VII collagen deficits alter TGFβ signaling and evoke multiple other cutaneous squamous cell carcinoma progression-promoting activities within epidermal microenvironments. This review examines cutaneous squamous cell carcinoma pathophysiology in dystrophic epidermolysis bullosa with a focus on known oncogenesis pathways at play and explores the idea that therapeutic type VII collagen replacement may reduce cutaneous squamous cell carcinoma risk.

Manipulating TGF-β signaling to optimize immunotherapy for cervical cancer

Cervical cancer is a serious threat to women's health globally. Therefore, identifying key molecules associated with cervical cancer progression is essential for drug development, disease monitoring, and precision therapy. Recently, TGF-β (transforming growth factor-beta) has been identified as a promising target for cervical cancer treatment. For advanced cervical cancer, TGF-β participates in tumor development by improving metastasis, stemness, drug resistance, and immune evasion. Accumulating evidence demonstrates that TGF-β blockade effectively improves the therapeutic effects, especially immunotherapy. Currently, agents targeting TGF-β and immune checkpoints such as PD-L1 have been developed and tested in clinical studies. These bispecific antibodies might have the potential as therapeutic agents for cervical cancer treatment in the future.

Forces exerted and transduced by cancer-associated fibroblasts during cancer progression

Although it is well-known that cancer-associated fibroblasts (CAFs) play a key role in regulating tumor progression, the effects of mechanical tissue changes on CAFs are understudied. Myofibroblastic CAFs (myCAFs), in particular, are known to alter tumor matrix architecture and composition, heavily influencing the mechanical forces in the tumor microenvironment (TME), but much less is known about how these mechanical changes initiate and maintain the myCAF phenotype. Additionally, recent studies have pointed to the existence of CAFs in circulating tumor cell clusters, indicating that CAFs may be subject to mechanical forces beyond the primary TME. Due to their pivotal role in cancer progression, targeting CAF mechanical regulation may provide therapeutic benefit. Here, we will discuss current knowledge and summarize existing gaps in how CAFs regulate and are regulated by matrix mechanics, including through stiffness, solid and fluid stresses, and fluid shear stress.

Fibroblasts as Turned Agents in Cancer Progression

Differentiated epithelial cells reside in the homeostatic microenvironment of the native organ stroma. The stroma supports their normal function, their G0 differentiated state, and their expansion/contraction through the various stages of the life cycle and physiologic functions of the host. When malignant transformation begins, the microenvironment tries to suppress and eliminate the transformed cells, while cancer cells, in turn, try to resist these suppressive efforts. The tumor microenvironment encompasses a large variety of cell types recruited by the tumor to perform different functions, among which fibroblasts are the most abundant. The dynamics of the mutual relationship change as the sides undertake an epic battle for control of the other. In the process, the cancer "wounds" the microenvironment through a variety of mechanisms and attracts distant mesenchymal stem cells to change their function from one attempting to suppress the cancer, to one that supports its growth, survival, and metastasis. Analogous reciprocal interactions occur as well between disseminated cancer cells and the metastatic microenvironment, where the microenvironment attempts to eliminate cancer cells or suppress their proliferation. However, the altered microenvironmental cells acquire novel characteristics that support malignant progression. Investigations have attempted to use these traits as targets of novel therapeutic approaches.

LRRC superfamily expression in stromal cells predicts the clinical prognosis and platinum resistance of ovarian cancer

BACKGROUND

Leucine-rich repeat sequence domains are known to mediate protein‒protein interactions. Recently, some studies showed that members of the leucine rich repeat containing (LRRC) protein superfamily may become new targets for the diagnosis and treatment of tumours. However, it is not known whether any of the LRRC superfamily genes is expressed in the stroma of ovarian cancer (OC) and is associated with prognosis.

METHODS

The clinical data and transcriptional profiles of OC patients from the public databases TCGA (n = 427), GTEx (n = 88) and GEO (GSE40266 and GSE40595) were analysed by R software. A nomogram model was also generated through R. An online public database was used for auxiliary analysis of prognosis, immune infiltration and protein‒protein interaction (PPI) networks. Immunohistochemistry and qPCR were performed to determine the protein and mRNA levels of genes in high-grade serous ovarian cancer (HGSC) tissues of participants and the MRC-5 cell line induced by TGF-β.

RESULTS

LRRC15 and LRRC32 were identified as differentially expressed genes from the LRRC superfamily by GEO transcriptome analysis. PPI network analysis suggested that they were most enriched in TGF-β signalling. The TCGA-GTEx analysis results showed that only LRRC15 was highly expressed in both cancer-associated fibroblasts (CAFs) and the tumour stroma of OC and was related to clinical prognosis. Based on this, we developed a nomogram model to predict the incidence of adverse outcomes in OC. Moreover, LRRC15 was positively correlated with CAF infiltration and negatively correlated with CD8 + T-cell infiltration. As a single indicator, LRRC15 had the highest accuracy (AUC = 0.920) in predicting the outcome of primary platinum resistance.

CONCLUSIONS

The LRRC superfamily is related to the TGF-β pathway in the microenvironment of OC. LRRC15, as a stromal biomarker, can predict the clinical prognosis of HGSC and promote the immunosuppressive microenvironment. LRRC15 may be a potential therapeutic target for reversing primary resistance in OC.

Biology of cancer; from cellular and molecular mechanisms to developmental processes and adaptation

Cancer research has been largely focused on the cellular and molecular levels of investigation. Recent data show that not only the cell but also the extracellular matrix plays a major role in the progression of malignancy. In this way, the cells and the extracellular matrix create a specific local microenvironment that supports malignant development. At the same time, cancer implies a systemic evolution which is closely related to developmental processes and adaptation. Consequently, there is currently a real gap between the local investigation of cancer at the microenvironmental level, and the pathophysiological approach to cancer as a systemic disease. In fact, the cells and the matrix are not only complementary structures but also interdependent components that act synergistically. Such relationships lead to cell-matrix integration, a supracellular form of biological organization that supports tissue development. The emergence of this supracellular level of organization, as a structure, leads to the emergence of the supracellular control of proliferation, as a supracellular function. In humans, proliferation is generally involved in developmental processes and adaptation. These processes suppose a specific configuration at the systemic level, which generates high-order guidance for local supracellular control of proliferation. In conclusion, the supracellular control of proliferation act as an interface between the downstream level of cell division and differentiation, and upstream level of developmental processes and adaptation. Understanding these processes and their disorders is useful not only to complete the big picture of malignancy as a systemic disease, but also to open new treatment perspectives in the form of etiopathogenic (supracellular or informational) therapies.

Exosomes Secreted from Mesenchymal Stem Cells Carry miR-486-5p to Inhibit Cell Proliferation and the Epithelial-Mesenchymal Transition Process to Treat Human Lung Cancer by Down-Regulating MIER3

Exosomes are nano-vesicles that can shuttle active cargoes. Mesenchymal stem cells play a complex function in tumour progression.We investigated the effect of miR-486-5p, an exosome of human bone marrow-derived MSCs on lung cancer. We found that miR-486-5p, carried in mesenchymal stem cells and mesenchymal stem cell-derived exosomes, regulates MIER3 expression by binding to its 3’UTR, thereby inhibiting the epithelial-mesenchymal transition process of A549 cells. In vivo, we demonstrated that exosome treatment reduced the area of tumour necrosis, increased the expression of miR-486-5p and inhibited the epithelial–mesenchymal transition process in mice. In conclusion, mesenchymal stem cell-derived exosomal miR-486-5p directly and negatively targets MIER3 to inhibit lung cancer.

Immunosuppressive Tumor Microenvironment and Immunotherapy of Epstein–Barr Virus-Associated Malignancies

The Epstein–Barr virus (EBV) can cause different types of cancer in human beings when the virus infects different cell types with various latent patterns. EBV shapes a distinct and immunosuppressive tumor microenvironment (TME) to its benefit by influencing and interacting with different components in the TME. Different EBV-associated malignancies adopt similar but slightly specific immunosuppressive mechanisms by encoding different EBV products to escape both innate and adaptive immune responses. Strategies reversing the immunosuppressive TME of EBV-associated malignancies have been under evaluation in clinical practice. As the interactions among EBV, tumor cells, and TME are intricate, in this review, we mainly discuss the epidemiology of EBV, the life cycle of EBV, the cellular and molecular composition of TME, and a landscape of different EBV-associated malignancies and immunotherapy by targeting the TME.

The Changing Landscape of Systemic Treatment for Cervical Cancer: Rationale for Inhibition of the TGF-β and PD-L1 Pathways

Cervical cancer is one of the most common and lethal cancers among women worldwide. Treatment options are limited in patients with persistent, recurrent, or metastatic cervical cancer, with <20% of women living >5 years. Persistent human papillomavirus (HPV) infection has been implicated in almost all cases of cervical cancer. HPV infection not only causes normal cervical cells to transform into cancer cells, but also creates an immunosuppressive environment for cancer cells to evade the immune system. Recent clinical trials of drugs targeting the PD-(L)1 pathway have demonstrated improvement in overall survival in patients with cervical cancer, but only 20% to 30% of patients show overall survival benefit beyond 2 years, and resistance to these treatments remains common. Therefore, novel treatment strategies targeting HPV infection-associated factors are currently being evaluated in clinical trials. Bintrafusp alfa is a first-in-class bifunctional fusion protein composed of the extracellular domain of the TGF-βRII receptor (a TGF-β "trap") fused to a human immunoglobulin G1 monoclonal antibody that blocks PD-L1. Early clinical trials of bintrafusp alfa have shown promising results in patients with advanced cervical cancer.

CaMKII Mediates TGFβ1-Induced Fibroblasts Activation and Its Cross Talk with Colon Cancer Cells

INTRODUCTION

Cancer-associated fibroblasts (CAFs), as the activated fibroblasts in tumor stroma, are important modifiers of tumor progression. TGFβ1 has been the mostly accepted factor to fuel normal fibroblasts transformation into CAFs. Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) is thought to play an important role in fibroblasts activation induced by TGFβ1. The aim of this study is to investigate the potential role of CaMKII in TGFβ1-induced fibroblasts activation and CAF-like differentiation. Cross talk between CaMKII-dependent fibroblasts and colon cancer in colon cancer progression also was addressed RESULTS: Immunostaining demonstrated that in colon cancer stroma, CaMKII overexpressed in stromal CAFs. In vitro, TGFβ1 increased CAF markers expression in human colon fibroblasts CCD-18Co, but not in CaMKII depletion fibroblasts. CaMKII knockdown by CaMKII shRNA significantly inhibited TGFβ1-induced fibroblasts activation and CAF-like differentiation. Smad3, AKT, and MAPK were targeted in TGFβ1-CaMKII-mediated pathway. Human colon cancer cell line HCT-116 activated fibroblasts directly, whereas CaMKII depletion dragged CCD-18Co fibroblasts undergoing CAF-associated trans-differentiation. Furthermore, increased proliferation, migration, and invasion of colon cancer cells were stimulated when co-cultured with normal fibroblasts, but not with CaMKII depletion fibroblasts.

CONCLUSIONS

These findings provide evidence that CaMKII is a critical mediator in TGFβ1-induced fibroblasts activation and is involved in the cross talk with colon cancer cells. CaMKII is a potentially effective target for future treatment of colon cancer.

Bone marrow mesenchymal stem cells promote the progression of prostate cancer through the SDF-1/CXCR4 axis in vivo and vitro

PURPOSE

The aim of this study was to investigate the involvement of the SDF-1/CXCR4 axis in the process of BMMSC homing in prostate cancer (PCa) in vivo and in vitro.

METHODS

After verification of BMMSCs, we fixed the concentration gradient of SDF-1 for BMMSC cultivation to analyze CXCR4 expression by qRT-PCR and flow cytometric analysis. Furthermore, we developed a non-contact co-culture system and explored the participation of the SDF-1/CXCR4 axis in PCa using qRT-PCR, flow cytometry, and ELISA. In addition, A green fluorescent protein (GFP)-transplanted methylnitrosourea (MNU)-induced PCa mouse model was established to investigate the CXCR4 expression in vivo.

RESULTS

The CXCR4 expression was up-regulated with the increase in SDF-1 concentrations, and elevated SDF-1 had a significant promoting effect on cell proliferation and migration in BMMSCs. Moreover, the CXCR4 expression of BMMSCs was significantly increased in the non-contact co-culture model with vascular endothelial cells (VECs), and analysis of this model also showed that the proliferation and migration of BMMSCs were promoted in the presence of VECs. The ELISA assay showed that the SDF-1 levels in the co-culture model at 48 h were significantly increased. Twenty of the GFP-transplanted mice were divided into a PCa group and a control group, and four GFP-transplanted mice were observed to have prostate tumorigenesis. It also showed that CXCR4 was obviously increased in the prostate tissue of PCa mice.

CONCLUSION

Our findings suggest that BMMSCs could home and promote the proliferation and migration of PCa through the SDF-1/CXCR4 axis in vivo and in vitro.

Metformin and sodium dichloroacetate effects on proliferation, apoptosis, and metabolic activity tested alone and in combination in a canine prostate and a bladder cancer cell line

An important approach in tumor therapy is combining substances with different action mechanisms aiming to enhance the antineoplastic effect, decrease the therapeutic dosage, and avoid resistance mechanisms. Moreover, evaluating compounds already approved for the treatment of non-neoplastic diseases is promising for new antineoplastic therapies. Sodium dichloroacetate (DCA) reactivates oxidative phosphorylation in the cancer cell mitochondria, reducing apoptosis resistance in cancer cells. Furthermore, metformin inhibits the proliferation of tumor cells and CD133+ cancer -stem-like cells. In the present study, we evaluated the independent and synergistic effect of metformin and DCA on the metabolic activity, cell proliferation, and apoptosis of a canine prostate adenocarcinoma (Adcarc1258) and a transitional cell carcinoma cell line (TCC1506) in comparison to a primary canine fibroblast culture. Determining metformin uptake in tumor cells was performed by quantitative HPLC. Depending on the dosage, metformin as a single agent inhibited the metabolic activity and cell proliferation of the tumor cells, showing only minor effects on the fibroblasts. Furthermore, 1 mM metformin increased apoptosis over 96 h in the tumor cell lines but not in fibroblasts. Additionally, metformin uptake into the tumor cells in vitro was measurable by quantitative HPLC. Synergistic effects for the combination therapy were observed in both neoplastic cell lines as well as in the fibroblasts. Based on these results, metformin might be a promising therapeutic agent for canine urogenital tumors. Further studies on kinetics, toxicology, bioavailability, and application of metformin in dogs are necessary.

The EBV-Encoded Oncoprotein, LMP1, Recruits and Transforms Fibroblasts via an ERK-MAPK-Dependent Mechanism

Latent membrane protein 1 (LMP1), the major oncoprotein encoded by Epstein–Barr virus (EBV), is expressed at widely variable levels in undifferentiated nasopharyngeal carcinoma (NPC) biopsies, fueling intense debate in the field as to the importance of this oncogenic protein in disease pathogenesis. LMP1-positive NPCs are reportedly more aggressive, and in a similar vein, the presence of cancer-associated fibroblasts (CAFs) surrounding “nests” of tumour cells in NPC serve as indicators of poor prognosis. However, there is currently no evidence linking LMP1 expression and the presence of CAFs in NPC. In this study, we demonstrate the ability of LMP1 to recruit fibroblasts in vitro in an ERK-MAPK-dependent mechanism, along with enhanced viability, invasiveness and transformation to a myofibroblast-like phenotype. Taken together, these findings support a putative role for LMP1 in recruiting CAFs to the tumour microenvironment in NPC, ultimately contributing to metastatic disease.

LAMC1 upregulation via TGFβ induces inflammatory cancer-associated fibroblasts in esophageal squamous cell carcinoma via NF-κB-CXCL1-STAT3

Cancer‐associated fibroblasts (CAF) are a heterogeneous cell population within the tumor microenvironment,and play an important role in tumor development. By regulating the heterogeneity of CAF, transforming growth factor β (TGFβ) influences tumor development. Here, we explored oncogenes regulated by TGFβ1 that are also involved in signaling pathways and interactions within the tumor microenvironment. We analyzed sequencing data of The Cancer Genome Atlas (TCGA) and our own previously established RNA microarray data (GSE53625), as well as esophageal squamous cell carcinoma (ESCC) cell lines with or without TGFβ1 stimulation. We then focused on laminin subunit gamma 1 (LAMC1), which was overexpressed in ESCC cells, affecting patient prognosis, which could be upregulated by TGFβ1 through the synergistic activation of SMAD family member 4 (SMAD4) and SP1. LAMC1 directly promoted the proliferation and migration of tumor cells, mainly via Akt–NFκB–MMP9/14 signaling. Additionally, LAMC1 promoted CXCL1 secretion, which stimulated the formation of inflammatory CAF (iCAF) through CXCR2–pSTAT3. Inflammatory CAF promoted tumor progression. In summary, we identified the dual mechanism by which the upregulation of LAMC1 by TGFβ in tumor cells not only promotes ESCC proliferation and migration, but also indirectly induces carcinogenesis by stimulating CXCL1 secretion to promote the formation of iCAF. This finding suggests that LAMC1 could be a potential therapeutic target and prognostic marker for ESCC.

TGF-β1-mediated transition of resident fibroblasts to cancer-associated fibroblasts promotes cancer metastasis in gastrointestinal stromal tumor

Cancer-associated fibroblasts (CAFs) are the most abundant cells in the tumor microenvironment. Crosstalk between tumor cells and CAFs contributes to tumor survival in most epithelial cancers. Recently, utilizing gastrointestinal stromal tumor (GIST) as a model for sarcomas, we identified paracrine networks by which CAFs promote tumor progression and metastasis. However, the mechanisms by which CAFs arise in sarcomas remain unclear. Here, RNA sequencing analysis revealed that transforming growth factor-β1 (TGF-β1) is highly expressed in both tumor cells and CAFs. To determine the functional role of TGF-β1, we treated normal gastric fibroblasts (GFs) with recombinant TGF-β1, which caused the GFs to adopt a more stellate morphology, as well as increased the mRNA expression of CAF-mediated genes (CCL2, RAB3B, and TNC) and genes encoding fibroblast growth factors (FGFs). Moreover, while either GIST or CAF conditioned media enhanced the transition from GFs to CAFs, a TGF-β1-blocking antibody attenuated this effect. Transwell migration assays revealed that the TGF-β1-mediated transition from GFs to CAFs enhanced tumor cell migration. This migratory effect was abrogated by an anti-TGF-β1 antibody, suggesting that TGF-β1 secreted from GIST cells or CAFs is associated with GIST migration via GF-to-CAF transition. In addition, the murine spleen-to-liver metastasis model showed that GF pre-treated with TGF-β1 promoted GIST metastasis. Collectively, these findings reveal unappreciated crosstalk among tumor cells, CAFs, and normal resident fibroblasts in the stroma of sarcomas, which enhances a GF-to-CAF transition associated with tumor migration and metastasis.

[Research Progress of Cancer-associated Fibroblasts in Lung Cancer]

肿瘤间质在肿瘤复发和治疗抵抗中起着关键作用。肿瘤相关成纤维细胞（cancer-associated fibroblasts, CAFs）是肺癌间质中最丰富、最关键的细胞成分之一，CAFs分泌多种炎性细胞因子及细胞外基质，形成纤维增生性小生境，在肺癌发生发展的各个方面都起着促进作用。肺癌CAFs具有多种不同的起源，主要由正常肺成纤维细胞在受到肿瘤源性细胞因子作用后所转化而来。不同CAFs亚群具有较大的异质性，其功能及作用机制也具有很大差异性；这给靶向CAFs的临床转化应用带来了很大的挑战。本综述重点阐述了CAFs的特性和功能研究中的新进展，同时强调CAFs在肺癌发生、发展中起到的作用及其特异性。

Hierarchically Releasing Bio-Responsive Nanoparticles for Complete Tumor Microenvironment Modulation via TGF-β Pathway Inhibition and TAF Reduction

The aggressive progression of breast cancer is impacted significantly by the tumor microenvironment (TME). The current chemotherapy normally causes cytotoxicity to tumor cells, while does not effectively modulate the TME. Thus, the chemotherapy effect of breast cancer is usually dissatisfactory. In this study, a kind of hierarchically releasing bio-responsive nanoparticles (R(D)/H(S) NPs), constructed by β-cyclodextrin-grafted heparin and pH-sensitive pseudorotaxane, were investigated to enhance the breast cancer chemotherapeutic efficacy through TME modulation. Doxorubicin (DOX) and transforming growth factor-β (TGF-β) receptor inhibitor (SB431542) loaded onto R(D)/H(S) NPs were released rapidly for the respective response to low pH in endosomes/lysosomes and heparanase (HPSE) in TME. Our results showed that R(D)/H(S) NPs effectively inhibited the formation of tumor-associated fibroblasts (TAFs) and reduced TGF-β and collagen I secretion. Besides, the immunosuppressive microenvironment was effectively reversed into immunogenic, characterized by increased CD8⁺ and CD4⁺ T cell infiltration, which distinctly inhibited breast cancer metastasis. Therefore, R(D)/H(S) NPs remodeled the TME by downregulating TAFs, TGF-β, and collagen I; activating the immune microenvironment; and then amplifying the chemotherapeutic efficacy of DOX.

Dysregulation of Transcription Factor Activity During Formation of Cancer-Associated Fibroblasts

The reciprocal interactions between cancer cells and the quiescent fibroblasts leading to the activation of cancer-associated fibroblasts (CAFs) serve an important role in cancer progression. Here, we investigated the activation of transcription factors (TFs) in prostate fibroblasts (WPMY cell line) co-cultured with normal prostate or tumorous cells (RWPE1 and RWPE2 cell lines, respectively). After indirect co-cultures, we performed mRNA-seq and predicted TF activity using mRNA expression profiles with the Systems EPigenomics Inference of Regulatory Activity (SEPIRA) package and the GTEx and mRNA-seq data of 483 cultured fibroblasts. The initial differential expression analysis between time points and experimental conditions showed that co-culture with normal epithelial cells mainly promotes an inflammatory response in fibroblasts, whereas with the cancerous epithelial, it stimulates transformation by changing the expression of the genes associated with microfilaments. TF activity analysis revealed only one positively regulated TF in the RWPE1 co-culture alone, while we observed dysregulation of 45 TFs (7 decreased activity and 38 increased activity) uniquely in co-culture with RWPE2. Pathway analysis showed that these 45 dysregulated TFs in fibroblasts co-cultured with RWPE2 cells may be associated with the RUNX1 and PTEN pathways. Moreover, we showed that observed dysregulation could be associated with FER1L4 expression. We conclude that phenotypic changes in fibroblast responses to co-culturing with cancer epithelium result from orchestrated dysregulation of signaling pathways that favor their transformation and motility rather than proinflammatory status. This dysregulation can be observed both at the TF and transcriptome levels.

Hypoxia theranostics of a human prostate cancer xenograft and the resulting effects on the tumor microenvironment

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Developed a hypoxia theranostic imaging strategy to eliminate hypoxic cells.

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Hypoxic cell elimination resulted in fewer cancer associated fibroblasts (CAFs)

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Collagen 1 fiber patterns were altered with hypoxic cell elimination.

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cDNA nanoparticles with HRE driven prodrug enzyme expression can target hypoxia.

Hypoxia is frequently observed in human prostate cancer, and is associated with chemoresistance, radioresistance, metastasis, and castrate-resistance. Our purpose in these studies was to perform hypoxia theranostics by combining in vivo hypoxia imaging and hypoxic cancer cell targeting in a human prostate cancer xenograft. This was achieved by engineering PC3 human prostate cancer cells to express luciferase as well as a prodrug enzyme, yeast cytosine deaminase, under control of hypoxic response elements (HREs). Cancer cells display an adaptive response to hypoxia through the activation of several genes mediated by the binding of hypoxia inducible factors (HIFs) to HRE in the promoter region of target gene that results in their increased transcription. HIFs promote key steps in tumorigenesis, including angiogenesis, metabolism, proliferation, metastasis, and differentiation. HRE-driven luciferase expression allowed us to detect hypoxia in vivo to time the administration of the nontoxic prodrug 5-fluorocytosine that was converted by yeast cytosine deaminase, expressed under HRE regulation, to the chemotherapy agent 5-fluorouracil to target hypoxic cells. Conversion of 5-fluorocytosine to 5-fluorouracil was detected in vivo by ¹⁹F magnetic resonance spectroscopy. Morphological and immunohistochemical staining and molecular analyses were performed to characterize tumor microenvironment changes in cancer-associated fibroblasts, cell viability, collagen 1 fiber patterns, and HIF-1α. These studies expand our understanding of the effects of eliminating hypoxic cancer cells on the tumor microenvironment and in reducing stromal cell populations such as cancer-associated fibroblasts.

Three-Dimensional Culture System of Cancer Cells Combined with Biomaterials for Drug Screening

Simple Summary

For the research and development of drug discovery, it is of prime importance to construct the three-dimensional (3D) tissue models in vitro. To this end, the enhancement design of cell function and activity by making use of biomaterials is essential. In this review, 3D culture systems of cancer cells combined with several biomaterials for anticancer drug screening are introduced.

Abstract

Anticancer drug screening is one of the most important research and development processes to develop new drugs for cancer treatment. However, there is a problem resulting in gaps between the in vitro drug screening and preclinical or clinical study. This is mainly because the condition of cancer cell culture is quite different from that in vivo. As a trial to mimic the in vivo cancer environment, there has been some research on a three-dimensional (3D) culture system by making use of biomaterials. The 3D culture technologies enable us to give cancer cells an in vitro environment close to the in vivo condition. Cancer cells modified to replicate the in vivo cancer environment will promote the biological research or drug discovery of cancers. This review introduces the in vitro research of 3D cell culture systems with biomaterials in addition to a brief summary of the cancer environment.

Tumour-derived exosomal miR-3473b promotes lung tumour cell intrapulmonary colonization by activating the nuclear factor-κB of local fibroblasts

Tumour‐derived exosomes have been shown to induce pre‐metastatic niche formation, favoring metastatic colonization of tumour cells, but the underlying molecular mechanism is still not fully understood. In this study, we showed that exosomes derived from the LLC cells could indeed significantly enhance their intrapulmonary colonization. Circulating LLC‐derived exosomes were mainly engulfed by lung fibroblasts and led to the NF‐κB signalling activation. Further studies indicated that the exosomal miR‐3473b was responsible for that by hindering the NFKB inhibitor delta's (NFKBID) function. Blocking miR‐3473b could reverse the exosome‐mediated NF‐κB activation of fibroblasts and decrease intrapulmonary colonization of lung tumour cells. Together, this study demonstrated that the miR‐3473b in exosomes could mediate the interaction of lung tumour cells and local fibroblasts in metastatic sites and, therefore, enhance the metastasis of lung tumour cells.

Mesenchymal stem cells maintain the stemness of colon cancer stem cells via interleukin-8/mitogen-activated protein kinase signaling pathway

Mesenchymal stem cells (MSCs) can act as a carrier in tumor therapy, and tumor suppressor gene-modified MSCs can reach and suppress the tumor. However, in the colon cancer microenvironment, MSCs could promote tumor growth and create the environment that is conducive to the survival of cancer stem cells (CSCs). This study discovered MSCs from three sources (bone marrow, adipose, placenta) could induce the stemness and epithelial–mesenchymal transition (EMT) of HCT116 in vitro, meanwhile adipose- and placenta-derived MSCs increase the proportion of CD133+/CD44+ HCT116. Then, we explored the interaction mechanism between CD133+/CD44+ HCT116 and MSCs by the bioinformatics and in vitro assays. After CD133+/CD44+ HCT116 were co-cultured with MSCs, many cytokines in MSCs were stimulated, including interleukin-8 (IL-8). The binding of IL-8/CXCR2 activates the downstream mitogen-activated protein kinase (MAPK) signaling pathway in colon CSCs, thereby promoting the stemness and EMT. However, inhibition of IL-8/CXCR2/Erk1/2 could reverse the effect of MSCs on CSC stemness. In addition, MSCs co-cultured with CD133+/CD44+ HCT116 produce a carcinoma-associated fibroblast phenotype via intracellular FGF10–PKA–Akt–β-catenin signaling, which can be attenuated by IL-8 peptide inhibitor. To conclude, IL-8 promotes the interaction between colon CSCs and MSCs, and activates the MAPK signaling pathway in colon CSCs, which provides a theoretical basis for the application of MSCs in clinical practice.

IMPACT STATEMENT

MSCs have the property of chemotaxis and they can migrate to the tumor site by paracrine pathway in the tumor environment, and then interact with tumor cells. Although a mass of studies have been conducted about the impact of MSCs on tumors, it is still controversial whether the exogenous MSCs promote or inhibit tumor growth. In this work, we evaluated the effects of MSCs from three sources (bone marrow, adipose, placenta) on the proliferation, stemness, and metastasis of the colon cancer cells both in vitro and in vivo. Then, we proved the IL-8/CXCR2/MAPK and FGF10–PKA–Akt–β-catenin signaling pathway which mediate the interplay between MSC and CD133+/CD44+ colon cancer cell. This research aims to provide a theoretical basis for the safe application of MSCs in the clinical treatment of colon cancer.

YAP1 plays a key role of the conversion of normal fibroblasts into cancer-associated fibroblasts that contribute to prostate cancer progression

Background

Cancer-associated fibroblasts (CAFs) are an important part of the tumour microenvironment, and their functions are of great concern. This series of experiments aimed to explore how Yes-associated protein 1 (YAP1) regulates the function of stromal cells and how the normal fibroblasts (NFs) convert into CAFs in prostate cancer (PCa).

Methods

The effects of conditioned media from different fibroblasts on the proliferation and invasion of epithelial cells TrampC1 were examined. We then analysed the interaction between the YAP1/TEAD1 protein complex and SRC, as well as the regulatory function of the downstream cytoskeletal proteins and actins. A transplanted tumour model was used to explore the function of YAP1 in regulating tumour growth through stromal cells. The relationship between the expression of YAP1 in tumour stromal cells and the clinical characteristics of PCa patients was analysed.

Results

The expression level of YAP1 was significantly upregulated in PCa stromal cells. After the expression level of YAP1 was increased, NF was transformed into CAF, enhancing the proliferation and invasion ability of epithelial cells. The YAP1/TEAD1 protein complex had the capability to influence downstream cytoskeletal proteins by regulating SRC transcription; therefore, it converts NF to CAF, and CAF can significantly promote tumour growth and metastasis. The high expression of YAP1 in the tumour stromal cells suggested a poor tumour stage and prognosis in PCa patients.

Conclusion

YAP1 can convert NFs into CAFs in the tumour microenvironment of PCa, thus promoting the development and metastasis of PCa. Silencing YAP1 in tumour stromal cells can effectively inhibit tumour growth.

Recent progress in the research of suicide gene therapy for malignant glioma

Malignant glioma, which is characterized by diffuse infiltration into the normal brain parenchyma, is the most aggressive primary brain tumor with dismal prognosis. Over the past 40 years, the median survival has only slightly improved. Therefore, new therapeutic modalities must be developed. In the 1990s, suicide gene therapy began attracting attention for the treatment of malignant glioma. Some clinical trials used a viral vector for suicide gene transduction; however, it was found that viral vectors cannot cover the large invaded area of glioma cells. Interest in this therapy was recently revived because some types of stem cells possess a tumor-tropic migratory capacity, which can be used as cellular delivery vehicles. Immortalized, clonal neural stem cell (NSC) line has been used for patients with recurrent high-grade glioma, which showed safety and efficacy. Embryonic and induced pluripotent stem cells may be considered as sources of NSC because NSC is difficult to harvest, and ethical issues have been raised. Mesenchymal stem cells are alternative candidates for cellular vehicle and are easily harvested from the bone marrow. In addition, a new type of nonlytic, amphotropic retroviral replicating vector encoding suicide gene has shown efficacy in patients with recurrent high-grade glioma in a clinical trial. This replicating viral capacity is another possible candidate as delivery vehicle to tackle gliomas. Herein, we review the concept of suicide gene therapy, as well as recent progress in preclinical and clinical studies in this field.

Blocking TGF-β Signaling To Enhance The Efficacy Of Immune Checkpoint Inhibitor

During malignant transformation, a growing body of mutations accumulate in cancer cells which not only drive cancer progression but also endow cancer cells with high immunogenicity. However, because one or multiple steps in cancer-immunity cycle are impaired, anti-cancer immune response is too weak to effectively clear cancer cells. Therefore, how to restore robust immune response to malignant cells is a hot research topic in cancer therapeutics field. In the last decade, based on the deeper understanding of cancer immunity, great signs of progress have been made in cancer immunotherapies especially immune checkpoint inhibitors (ICIs). ICIs could block negative immune co-stimulatory pathways and reactivate tumor-infiltrating lymphocytes (TILs) from exhausted status. ICIs exhibit potent anti-cancer effect and have been approved for the treatment of numerous cancer types. Parallel with durable and effective tumor control, the actual response rate of ICIs is unsatisfactory. Although a subset of patients benefit from ICIs treatment, a large proportion of patients show primary or acquired resistance. Previously intensive studies indicated that the efficacy of ICIs was determined by a series of factors including tumor mutation burden, programmed death ligand-1 (PD-L1) expression, and TILs status. Recently, it was reported that transforming growth factor-beta (TGF-β) signaling pathway participated in cancer immune escape and ICI resistance. Concurrent TGF-β blockade might be a feasible strategy to enhance the efficacy of immunotherapy and relieve ICI resistance. In this mini-review, we summarized the latest understanding of TGF-β signaling pathway and cancer immunity. Besides, we highlighted the synergistic effect of TGF-β blockade and ICIs.

The Safe and Efficacious Use of Secretome From Fibroblasts and Adipose-derived (but not Bone Marrow-derived) Mesenchymal Stem Cells for Skin Therapeutics

Stem cell-based products are rapidly emerging in the marketplace as topical skin care and wound care products. Confusion is prevalent among healthcare providers and end-users about these products. Adipose-derived stem cells, fibroblasts, platelets, and bone marrow-derived stem cells are the most common cells used for stem cell therapeutic development, medical procedures, and skin care products. In this review, the significant advantages of adipose-derived stem cells and fibroblasts in terms of safety and efficacy are highlighted and compared to relatively risky platelets and bone marrow stem cells.

Effect of mesenchymal stem cells-derived exosomes on tumor microenvironment: Tumor progression versus tumor suppression

Mesenchymal stem cells (MSCs) are multipotent cells with the potential to differentiate into different cell types. Owing to their immunosuppressive and anti-inflammatory properties, they are widely used in regenerative medicine, but they have a dual effect on cancer progression and exert both growth-stimulatory or -inhibitory effects on different cancer types. It has been proposed that these controversial effects of MSC in tumor microenvironment (TME) are mediated by their polarization to proinflammatory or anti-inflammatory phenotype. In addition, they can polarize the immune system cells that in turn influence tumor progression. One of the mechanisms involved in the TME communications is extracellular vesicles (EVs). MSCs, as one of cell populations in TME, produce a large amount of EVs that can influence tumor development. Similar to MSC, MSC-EVs can exert both anti- or protumorigenic effects. In the current study, we will investigate the current knowledge related to MSC role in cancer progression with a focus on the MSC-EV content in limiting tumor growth, angiogenesis, and metastasis. We suppose MSC-EVs can be used as safe vehicles for delivering antitumor agents to TME.

Cellular Constituents of the Prostate Stroma: Key Contributors to Prostate Cancer Progression and Therapy Resistance

Reciprocal signaling between prostate stroma and its epithelium are fundamental to organ development and homeostasis. Similarly, interactions between tumor cells and stromal constituents are central to key aspects of carcinogenesis and malignancy growth involving tumor cell invasion, dissemination, and growth in distant sites. The prostate stroma is complex with several distinct resident cell types, infiltrating nonresident cell types and an amalgam of structural matrix factors, matricellular proteins, metabolites, growth factors, and cytokines. Of importance, the stroma is dynamic with changes in composition as a cause or consequence of intrinsic and extrinsic factors. In the context of epithelial neoplasia, the prostate stroma undergoes phenotypic changes with a loss of well-differentiated smooth muscle cell population and the expansion of cancer-associated fibroblast populations. This reactive stroma further coevolves with tumor progression. Recent studies show the role of tumor microenvironment components in therapy resistance and highlight the importance of a thorough knowledge of cross talk between tumor cells and microenvironment niches to develop new therapeutic strategies.

Cancer-associated fibroblasts in tumor microenvironment - Accomplices in tumor malignancy

There is much cellular heterogeneity in the tumor microenvironment. The tumor epithelia and stromal cells co-evolve, and this reciprocal relationship dictates almost every step of cancer development and progression. Despite this, many anticancer therapies are designed around druggable features of tumor epithelia, ignoring the supportive role of stromal cells. Cancer-associated fibroblasts (CAFs) are the dominant cell type within the reactive stroma of many tumor types. Numerous previous studies have highlighted a pro-tumorigenic role for CAFs via secretion of various growth factors, cytokines, chemokines, and the degradation of extracellular matrix. Recent works showed that CAFs secrete H₂O₂ to effect stromal-mediated field cancerization, transform primary epithelial cells, and aggravate cancer cell aggressiveness, in addition to inflammatory and mitogenic factors. Molecular characterization of CAFs also underscores the importance of Notch and specific nuclear receptor signaling in the activation of CAFs. This review consolidates recent findings of CAFs and highlights areas for future investigations.

On metabolic reprogramming and tumor biology: A comprehensive survey of metabolism in breast cancer

Altered metabolism in tumor cells has been a focus of cancer research for as long as a century but has remained controversial and vague due to an inhomogeneous overall picture. Accumulating genomic, metabolomic, and lastly panomic data as well as bioenergetics studies of the past few years enable a more comprehensive, systems-biologic approach promoting deeper insight into tumor biology and challenging hitherto existing models of cancer bioenergetics. Presenting a compendium on breast cancer-specific metabolome analyses performed thus far, we review and compile currently known aspects of breast cancer biology into a comprehensive network, elucidating previously dissonant issues of cancer metabolism. As such, some of the aspects critically discussed in this review include the dynamic interplay or metabolic coupling between cancer (stem) cells and cancer-associated fibroblasts, the intratumoral and intertumoral heterogeneity and plasticity of cancer cell metabolism, the existence of distinct metabolic tumor compartments in need of separate yet simultaneous therapeutic targeting, the reliance of cancer cells on oxidative metabolism and mitochondrial power, and the role of pro-inflammatory, pro-tumorigenic stromal conditioning. Comprising complex breast cancer signaling networks as well as combined metabolomic and genomic data, we address metabolic consequences of mutations in tumor suppressor genes and evaluate their contribution to breast cancer predisposition in a germline setting, reasoning for distinct personalized preventive and therapeutic measures. The review closes with a discussion on central root mechanisms of tumor cell metabolism and rate-limiting steps thereof, introducing essential strategies for therapeutic targeting.

Prospects for combined use of oncolytic viruses and CAR T-cells

With the approval of talimogene laherparepvec (T-VEC) for inoperable locally advanced or metastatic malignant melanoma in the USA and Europe, oncolytic virotherapy is now emerging as a viable therapeutic option for cancer patients. In parallel, following the favourable results of several clinical trials, adoptive cell transfer using chimeric antigen receptor (CAR)-redirected T-cells is anticipated to enter routine clinical practice for the management of chemotherapy-refractory B-cell malignancies. However, CAR T-cell therapy for patients with advanced solid tumours has proved far less successful. This Review draws upon recent advances in the design of novel oncolytic viruses and CAR T-cells and provides a comprehensive overview of the synergistic potential of combination oncolytic virotherapy with CAR T-cell adoptive cell transfer for the management of solid tumours, drawing particular attention to the methods by which recombinant oncolytic viruses may augment CAR T-cell trafficking into the tumour microenvironment, mitigate or reverse local immunosuppression and enhance CAR T-cell effector function and persistence.

Human-derived normal mesenchymal stem/stromal cells in anticancer therapies

The tumor microenvironment (TME) not only plays a pivotal role during cancer progression and metastasis, but also has profound effects on therapeutic efficacy. Stromal cells of the TME are increasingly becoming a key consideration in the development of active anticancer therapeutics. However, dispute concerning the role of stromal cells to fight cancer continues because the use of mesenchymal stem/stromal cells (MSCs) as an anticancer agent is dependent on the specific MSCs subtype, in vitro or in vivo conditions, factors secreted by MSCs, types of cancer cell lines and interactions between MSCs, cancer cells and host immune cells. In this review, we mainly focus on the role of human-derived normal MSCs in anticancer therapies. We first discuss the use of different MSCs in the therapies for various cancers. We then focus on their anticancer mechanism and clinical application.

Prostate cancer stem cells: the role of androgen and estrogen receptors

Prostate cancer is one of the most commonly diagnosed cancers in men, and androgen deprivation therapy still represents the primary treatment for prostate cancer patients. This approach, however, frequently fails and patients develop castration-resistant prostate cancer, which is almost untreatable.

Cancer cells are characterized by a hierarchical organization, and stem/progenitor cells are endowed with tumor-initiating activity. Accumulating evidence indicates that prostate cancer stem cells lack the androgen receptor and are, indeed, resistant to androgen deprivation therapy. In contrast, these cells express classical (α and/or β) and novel (GPR30) estrogen receptors, which may represent new putative targets in prostate cancer treatment.

In the present review, we discuss the still-debated mechanisms, both genomic and non-genomic, by which androgen and estradiol receptors (classical and novel) mediate the hormonal control of prostate cell stemness, transformation, and the continued growth of prostate cancer. Recent preclinical and clinical findings obtained using new androgen receptor antagonists, anti-estrogens, or compounds such as enhancers of androgen receptor degradation and peptides inhibiting non-genomic androgen functions are also presented. These new drugs will likely lead to significant advances in prostate cancer therapy.

IL-6/STAT3 axis initiated CAFs via up-regulating TIMP-1 which was attenuated by acetylation of STAT3 induced by PCAF in HCC microenvironment

Aberrant tumor microenvironment is involved closely in tumor initiation and progression, in which cancer associated fibroblasts (CAFs) play a pivotal role. Both IL-6/STAT3 signaling and TIMP-1 have been found to modulate the crosstalk between tumor cells and CAFs in tumor microenvironment, however, the underlying mechanism remains unclear. Here, we showed that IL-6/STAT3 signaling was activated aberrantly in HCC tissues and correlated with poor post-surgical outcome. The in vitro experiments confirmed that activation of IL-6/STAT3 pathway enhanced TIMP-1 expression directly via phosphorylated STATs (p-STAT3)-binding with TIMP-1 promoter in Huh7 cells. Furthermore, activation of IL-6/STAT3 pathway in HCC cells was shown to induce the transformation from normal liver fibroblasts (LFs) to CAFs via up-regulating TIMP-1 expression. Co-culture with CAFs promoted the growth of Huh7 cells both in vitro and in vivo. Finally, by co-Immunoprecipitation and immunoblotting assessments, PCAF, a well-known acetyltransferase, was revealed to acetylate cytoplasmic STAT3 protein directly and regulate TIMP-1 expression negatively in Huh7 cells. In summary, this investigation indicated that there was a positive IL-6/TIMP-1 feedback loop controlling the crosstalk between HCC cells and its neighbouring fibroblasts. The data here also identified that PCAF repressed TIMP-1 expression via acetylation of STAT3. In conclusion, this investigation demonstrated that CAFs promoted HCC growth via IL-6/STAT3/AKT pathway and TIMP-1 over-expression driven by IL-6/STAT3 pathway in HCC cells brought in more CAFs through activating LFs. Finally, PCAF could block this positive feedback by acetylating STAT3 in HCC cells.

CAF cellular glycolysis: linking cancer cells with the microenvironment

Cancers have long being hallmarked as cells relying heavily on their glycolysis for energy generation in spite of having functional mitochondria. The metabolic status of the cancer cells have been revisited time and again to get better insight into the overall carcinogenesis process which revealed the apparent crosstalks between the cancer cells with the fibroblasts present in the tumour microenvironment. This review focuses on the mechanisms of transformations of normal fibroblasts to cancer-associated fibroblasts (CAF), the participation of the CAF in tumour progression with special interest to the role of CAF cellular glycolysis in the overall tumorigenesis. The fibroblasts, when undergoes the transformation process, distinctly switches to a more glycolytic phenotype in order to provide the metabolic intermediates necessary for carrying out the mitochondrial pathways of ATP generation in cancer cells. This review will also discuss the molecular mechanisms responsible for this metabolic make over promoting glycolysis in CAF cells. A thorough investigation of the pathways and molecules involved will not only help in understanding the process of activation and metabolic reprogramming in CAF cells but also might open up new targets for cancer therapy.

Carcinoma-Associated Fibroblasts Lead the Invasion of Salivary Gland Adenoid Cystic Carcinoma Cells by Creating an Invasive Track

Carcinoma-associated fibroblasts (CAFs) are critical in determining tumor invasion and metastasis. However the role of CAFs in the invasion of salivary gland adenoid cystic carcinoma (ACC) is poorly understood. In this study, we isolated primary CAFs from two ACC patients. ACC-derived CAFs expressed typical CAF biomarkers and showed increased migration and invasion activity. Conditioned medium collected from CAFs significantly promoted ACC cell migration and invasion. Co-culture of CAFs with ACC cells in a microfluidic device further revealed that CAFs localized at the invasion front and ACC cells followed the track behind the CAFs. Interfering of both matrix metalloproteinase and CXCL12/CXCR4 pathway inhibited ACC invasion promoted by CAFs. Overall, our study demonstrates that ACC-derived CAFs exhibit the most important defining feature of CAFs by promoting cancer invasion. In addition to secretion of soluble factors, CAFs also lead ACC invasion by creating an invasive track in the ECM.

Cancer-Associated Fibroblasts: Their Characteristics and Their Roles in Tumor Growth

Cancer tissues are composed of cancer cells and the surrounding stromal cells (e.g., fibroblasts, vascular endothelial cells, and immune cells), in addition to the extracellular matrix. Most studies investigating carcinogenesis and the progression, invasion, metastasis, and angiogenesis of cancer have focused on alterations in cancer cells, including genetic and epigenetic changes. Recently, interactions between cancer cells and the stroma have attracted considerable attention, and increasing evidence has accumulated on this. Several researchers have gradually clarified the origins, features, and roles of cancer-associated fibroblasts (CAFs), a major component of the cancer stroma. CAFs function in a similar manner to myofibroblasts during wound healing. We previously reported the relationship between CAFs and angiogenesis. Interleukin-6 (IL-6), a multifunctional cytokine, plays a central role in regulating inflammatory and immune responses, and important roles in the progression, including proliferation, migration, and angiogenesis, of several cancers. We showed that CAFs are an important IL-6 source and that anti-IL-6 receptor antibody suppressed angiogenesis and inhibited tumor-stroma interactions. Furthermore, CAFs contribute to drug-resistance acquisition in cancer cells. The interaction between cancer cells and the stroma could be a potential target for anti-cancer therapy.