TGF-beta receptor type-2 expression in cancer-associated fibroblasts regulates breast cancer cell growth and survival and is a prognostic marker in pre-menopausal breast cancer

Snail1 as a key prognostic biomarker of cancer-associated fibroblasts in breast tumors

Accurate cancer diagnosis is crucial for selecting optimal treatments, yet current classification systems often include non-responders who receive ineffective therapies. Cancer-associated fibroblasts (CAFs) play a central role in tumor progression, and CAF biomarkers are increasingly recognized for their prognostic value. Recent studies have revealed significant heterogeneity within CAF populations, with distinct subtypes linked to different tumors and stages of disease. In this review, we summarize recent findings from patient samples and mouse models of breast cancer, focusing on gene signatures identified by single-cell RNA sequencing that define CAF subtypes and predict cancer prognosis. Additionally, we explore the genes and pathways regulated by Snail1, a transcription factor whose expression in breast and colon CAFs is associated with malignancy. Altogether these data emphasize the fibrotic and immunosuppressive roles of Snail1-expressing fibroblasts and unveil an undescribed streamlined Snail1-related gene signature in CAFs with prognostic potential in breast cancer and other solid tumors.

Deciphering the heterogeneity and plasticity of the tumor microenvironment in liver cancer provides insights for prognosis

Liver cancer exhibits diverse molecular characteristics and distinct immune cell infiltration patterns, which significantly influence patient outcomes. In this study, we thoroughly examined the liver cancer tumor environment by analyzing data from 419,866 individual cells across nine datasets involving 99 patients. By categorizing patients into different groups based on their immune cell profiles, including immune deficiency, B cells-enriched, T cells-enriched and macrophages-enriched, we better understood how these cells change in various patient subgroups. Our investigation of liver metastases from intestinal cancer uncovered a group of mast cells that might promote metastasis through pathways like inositol phosphate metabolism. Using genomic and clinical data from The Cancer Genome Atlas, we identified specific cell components linked to tumor characteristics and genetics. Our detailed study of cancer-associated fibroblasts (CAFs) revealed how they adapt and acquire new functions in the tissue environment, highlighting their flexibility. Additionally, we found a significant connection between CAF-related genes and the prognosis of hepatocellular carcinoma patients. This research provides valuable insights into the makeup of the liver cancer tumor environment and its profound impact on patient outcomes, offering fresh perspectives for managing this challenging disease.

Comparison of differences in immune cells and immune microenvironment among different kinds of oncolytic virus treatments

Oncolytic viruses are either naturally occurring or genetically engineered viruses that can activate immune cells and selectively replicate in and destroy cancer cells without damaging healthy tissues. Oncolytic virus therapy (OVT) represents an emerging treatment approach for cancer. In this review, we outline the properties of oncolytic viruses and then offer an overview of the immune cells and tumor microenvironment (TME) across various OVTs. A thorough understanding of the immunological mechanisms involved in OVTs could lead to the identification of novel and more effective therapeutic targets for cancer treatment.

Molecular mechanism of PARP inhibitor resistance

Poly (ADP-ribose) polymerases (PARP) inhibitors (PARPi) are the first-approved anticancer drug designed to exploit synthetic lethality. PARPi selectively kill cancer cells with homologous recombination repair deficiency (HRD), as a result, PARPi are widely employed to treated BRCA1/2-mutant ovarian, breast, pancreatic and prostate cancers. Currently, four PARPi including Olaparib, Rucaparib, Niraparib, and Talazoparib have been developed and greatly improved clinical outcomes in cancer patients. However, accumulating evidences suggest that required or de novo resistance emerged. In this review, we discuss the molecular mechanisms leading to PARPi resistances and review the potential strategies to overcome PARPi resistance.

Core needle biopsy changes the expression of TGFβ1 and TGFβRII at protein level, and the distribution of CD4 and CD8 positive T cells in primary breast cancer

Core needle biopsy (CNB) has become a paradigm in preoperative breast cancer (BC) diagnosis. Although considered safe, it is an invasive procedure, which changes the tumor microenvironment. It facilitates a tumor supportive immune response, induces epithelial-mesenchymal transition (EMT), and enables the release of circulating tumor cells. The cytokine Transforming Growth Factor β (TGFβ) with its pleiotropic immunologic functions has an important role in this process. The aim of this study was to clarify the specific impact of CNB on the activity of the TGFβ pathway in early BC. We compared formalin fixed paraffin embedded samples from CNBs to the corresponding surgical resection specimens (SRSs) of 49 patients with BC. We found that the expression of TGFβ1 at protein level was significantly higher in both tumor epithelial and benign stromal cells in the SRSs (p=0.001), whereas the expression of TGFβRII in tumor cells was lower (p=0.001). The frequency of intra tumoral CD8 and CD4 positive T lymphocytes was lower in SRSs (p=0081 and p=0001, respectively), while in the peripheral stroma their prevalence was increased (p=0001 and p=0012, respectively). Our results show that CNB changes the hallmarks of the TGFβ path way in early BC. These CNB-induced changes in the tumor and in its microenvironment suggest that the procedure may change the immunological anti-tumor response of the host.

Molecular and Histopathological Characterization of Metastatic Cutaneous Squamous Cell Carcinomas: A Case-Control Study

BACKGROUND

A subset of patients affected by cutaneous squamous cell carcinoma (cSCC) can exhibit locally invasive or metastatic tumors. Different staging classification systems are currently in use for cSCC. However, precise patient risk stratification has yet to be reached in clinical practice. The study aims to identify specific histological and molecular parameters characterizing metastatic cSCC.

METHODS

Patients affected by metastatic and non-metastatic cSCC (controls) were included in the present study and matched for clinical and histological characteristics. Skin samples from primary tumors were revised for several histological parameters and also underwent gene expression profiling with a commercially available panel testing 770 different genes.

RESULTS

In total, 48 subjects were enrolled in the study (24 cases, 24 controls); 67 genes were found to be differentially expressed between metastatic and non-metastatic cSCC. Most such genes were involved in immune regulation, skin integrity, angiogenesis, cell migration and proliferation.

CONCLUSION

The combination of histological and molecular profiles of cSCCs allows the identification of features specific to metastatic cSCC, with potential implications for more precise patient risk stratification.

Targeting the Tumor Microenvironment in Breast Cancer: Prognostic and Predictive Significance and Therapeutic Opportunities

Breast cancer is one of the most prevalent tumors among women. Its prognosis and treatment outcomes depend on factors related to tumor cell biology. However, recent studies have revealed the critical role of the tumor microenvironment (TME) in the development, progression, and treatment response of breast cancer. In this review, we explore the different components of the TME and their relevance as prognostic and predictive biomarkers in breast cancer. In addition, techniques for assessing the tumor microenvironment, such as immunohistochemistry or gene expression profiling, and their clinical utility in therapeutic decision-making are examined. Finally, therapeutic strategies targeting the TME are reviewed, highlighting their potential clinical benefits. Overall, this review emphasizes the importance of the TME in breast cancer and its potential as a clinical tool for better patient stratification and the design of personalized therapies.

Crosstalk and plasticity driving between cancer-associated fibroblasts and tumor microenvironment: significance of breast cancer metastasis

Cancer-associated fibroblasts (CAFs) are the most abundant stromal cell population in breast tumors. A functionally diverse population of CAFs increases the dynamic complexity of the tumor microenvironment (TME). The intertwined network of the TME facilitates the interaction between activated CAFs and breast cancer cells, which can lead to the proliferation and invasion of breast cells. Considering the special transmission function of CAFs, the aim of this review is to summarize and highlight the crosstalk between CAFs and breast cancer cells in the TME as well as the relationship between CAFs and extracellular matrix (ECM), soluble cytokines, and other stromal cells in the metastatic state. The crosstalk between cancer-associated fibroblasts and tumor microenvironment also provides a plastic therapeutic target for breast cancer metastasis. In the course of the study, the inhibitory effects of different natural compounds on targeting CAFs and the advantages of different drug combinations were summarized. CAFs are also widely used in the diagnosis and treatment of breast cancer. The cumulative research on this phenomenon supports the establishment of a targeted immune microenvironment as a possible breakthrough in the prevention of invasive metastasis of breast cancer.

The Role of the Transforming Growth Factor-β Signaling Pathway in Gastrointestinal Cancers

Transforming growth factor-β (TGF-β) has attracted attention as a tumor suppressor because of its potent growth-suppressive effect on epithelial cells. Dysregulation of the TGF-β signaling pathway is considered to be one of the key factors in carcinogenesis, and genetic alterations affecting TGF-β signaling are extraordinarily common in cancers of the gastrointestinal system, such as hereditary nonpolyposis colon cancer and pancreatic cancer. Accumulating evidence suggests that TGF-β is produced from various types of cells in the tumor microenvironment and mediates extracellular matrix deposition, tumor angiogenesis, the formation of CAFs, and suppression of the anti-tumor immune reaction. It is also being considered as a factor that promotes the malignant transformation of cancer, particularly the invasion and metastasis of cancer cells, including epithelial-mesenchymal transition. Therefore, elucidating the role of TGF-β signaling in carcinogenesis, cancer invasion, and metastasis will provide novel basic insight for diagnosis and prognosis and the development of new molecularly targeted therapies for gastrointestinal cancers. In this review, we outline an overview of the complex mechanisms and functions of TGF-β signaling. Furthermore, we discuss the therapeutic potentials of targeting the TGF-β signaling pathway for gastrointestinal cancer treatment and discuss the remaining challenges and future perspectives on targeting this pathway.

Regulations of Tumor Microenvironment by Prostaglandins

Prostaglandins, the bioactive lipids generated from the metabolism of arachidonic acid through cyclooxygenases, have potent effects on many constituents of tumor microenvironments. In this review, we will describe the formation and activities of prostaglandins in the context of the tumor microenvironment. We will discuss the regulation of cancer-associated fibroblasts and immune constituents by prostaglandins and their roles in immune escapes during tumor progression. The review concludes with future perspectives on improving the efficacy of immunotherapy through repurposing non-steroid anti-inflammatory drugs and other prostaglandin modulators.

Cancer-associated fibroblasts and its derived exosomes: a new perspective for reshaping the tumor microenvironment

Cancer-associated fibroblasts (CAFs) are the most abundant stromal cells within the tumor microenvironment (TME). They extensively communicate with the other cells. Exosome-packed bioactive molecules derived from CAFs can reshape the TME by interacting with other cells and the extracellular matrix, which adds a new perspective for their clinical application in tumor targeted therapy. An in-depth understanding of the biological characteristics of CAF-derived exosomes (CDEs) is critical for depicting the detailed landscape of the TME and developing tailored therapeutic strategies for cancer treatment. In this review, we have summarized the functional roles of CAFs in the TME, particularly focusing on the extensive communication mediated by CDEs that contain biological molecules such as miRNAs, proteins, metabolites, and other components. In addition, we have also highlighted the prospects for diagnostic and therapeutic applications based on CDEs, which could guide the future development of exosome-targeted anti-tumor drugs.

The "Self-eating" of cancer-associated fibroblast: A potential target for cancer

Autophagy helps maintain energy homeostasis and protect cells from stress effects by selectively removing misfolded/polyubiquitylated proteins, lipids, and damaged mitochondria. Cancer-associated fibroblasts (CAFs) are cellular components of tumor microenvironment (TME). Autophagy in CAFs inhibits tumor development in the early stages; however, it has a tumor-promoting effect in advanced stages. In this review, we aimed to summarize the modulators responsible for the induction of autophagy in CAFs, such as hypoxia, nutrient deprivation, mitochondrial stress, and endoplasmic reticulum stress. In addition, we aimed to present autophagy-related signaling pathways in CAFs, and role of autophagy in CAF activation, tumor progression, tumor immune microenvironment. Autophagy in CAFs may be an emerging target for tumor therapy. In summary, autophagy in CAFs is regulated by a variety of modulators and can reshape tumor immune microenvironment, affecting tumor progression and treatment.

Cancer-associated fibroblasts: Versatile mediators in remodeling the tumor microenvironment

Current cancer therapeutic strategies are generally not sufficient to eradicate malignancy, as cancer stroma cells contribute to tumor evasion and therapeutic resistance. Cancer-associated fibroblasts (CAFs) constitute a largely heterogeneous type of stromal cell population and are important components of the tumor microenvironment (TME). CAFs are the most abundant stromal cell type and are actively involved in tumor progression through complex mechanisms involving effects on other cell types. Research conducted in recent years has emphasized an emerging function of CAFs in the remodeling of the TME that promotes tumor progression with effects on response to treatment by various molecular mechanisms. A comprehensive mechanism of tumor-promoting activities of CAFs could facilitate the development of novel diagnostic and therapeutic approaches. In this review, the biological characterization of CAFs and the mechanisms of their effects on TME remodeling are summarized. Furthermore, we also highlight currently available therapeutic strategies targeting CAF in the context of optimizing the success of immunotherapies and briefly discuss possible future perspectives and challenges related to CAF studies.

The Tumor Microenvironment in Tumorigenesis and Therapy Resistance Revisited

Tumorigenesis is a complex and dynamic process involving cell-cell and cell-extracellular matrix (ECM) interactions that allow tumor cell growth, drug resistance and metastasis. This review provides an updated summary of the role played by the tumor microenvironment (TME) components and hypoxia in tumorigenesis, and highlight various ways through which tumor cells reprogram normal cells into phenotypes that are pro-tumorigenic, including cancer associated- fibroblasts, -macrophages and -endothelial cells. Tumor cells secrete numerous factors leading to the transformation of a previously anti-tumorigenic environment into a pro-tumorigenic environment. Once formed, solid tumors continue to interact with various stromal cells, including local and infiltrating fibroblasts, macrophages, mesenchymal stem cells, endothelial cells, pericytes, and secreted factors and the ECM within the tumor microenvironment (TME). The TME is key to tumorigenesis, drug response and treatment outcome. Importantly, stromal cells and secreted factors can initially be anti-tumorigenic, but over time promote tumorigenesis and induce therapy resistance. To counter hypoxia, increased angiogenesis leads to the formation of new vascular networks in order to actively promote and sustain tumor growth via the supply of oxygen and nutrients, whilst removing metabolic waste. Angiogenic vascular network formation aid in tumor cell metastatic dissemination. Successful tumor treatment and novel drug development require the identification and therapeutic targeting of pro-tumorigenic components of the TME including cancer-associated- fibroblasts (CAFs) and -macrophages (CAMs), hypoxia, blocking ECM-receptor interactions, in addition to the targeting of tumor cells. The reprogramming of stromal cells and the immune response to be anti-tumorigenic is key to therapeutic success. Lastly, this review highlights potential TME- and hypoxia-centered therapies under investigation.

Exosomes-mediated tumor metastasis through reshaping tumor microenvironment and distant niche

Tumor-derived exosomes (TDEs) are the particular communicator and messenger between tumor cells and other cells containing cancer-associated genetic materials and proteins. And TDEs who are also one of the important components consisting of the tumor microenvironment (TME) can reshape and interact with TME to promote tumor development and metastasis. Moreover, due to their long-distance transmission by body fluids, TDEs can facilitate the formation of pre-metastatic niche to support tumor colonization. We discuss the main characteristics and mechanism of TDE-mediated tumor metastasis by reshaping TME and pre-metastatic niche as well as the potential of TDEs for diagnosing tumor and predicting future metastatic development.

Biological Effects of Human Exposure to Environmental Cadmium

Cadmium (Cd) is a toxic metal for the human organism and for all ecosystems. Cd is naturally found at low levels; however, higher amounts of Cd in the environment result from human activities as it spreads into the air and water in the form of micropollutants as a consequence of industrial processes, pollution, waste incineration, and electronic waste recycling. The human body has a limited ability to respond to Cd exposure since the metal does not undergo metabolic degradation into less toxic species and is only poorly excreted. The extremely long biological half-life of Cd essentially makes it a cumulative toxin; chronic exposure causes harmful effects from the metal stored in the organs. The present paper considers exposure and potential health concerns due to environmental cadmium. Exposure to Cd compounds is primarily associated with an elevated risk of lung, kidney, prostate, and pancreatic cancer. Cd has also been linked to cancers of the breast, urinary system, and bladder. The multiple mechanisms of Cd-induced carcinogenesis include oxidative stress with the inhibition of antioxidant enzymes, the promotion of lipid peroxidation, and interference with DNA repair systems. Cd²⁺ can also replace essential metal ions, including redox-active ones. A total of 12 cancer types associated with specific genes coding for the Cd-metalloproteome were identified in this work. In addition, we summarize the proper treatments of Cd poisoning, based on the use of selected Cd detoxifying agents and chelators, and the potential for preventive approaches to counteract its chronic exposure.

Receptor-Mediated Redox Imbalance: An Emerging Clinical Avenue against Aggressive Cancers

Cancer cells are more vulnerable to abnormal redox fluctuations due to their imbalanced antioxidant system, where cell surface receptors sense stress and trigger intracellular signal relay. As canonical targets of many targeted therapies, cell receptors sensitize the cells to specific drugs. On the other hand, cell target mutations are commonly associated with drug resistance. Thus, exploring effective therapeutics targeting diverse cell receptors may open new clinical avenues against aggressive cancers. This paper uses focused case studies to reveal the intrinsic relationship between the cell receptors of different categories and the primary cancer hallmarks that are associated with the responses to external or internal redox perturbations. Cold atmospheric plasma (CAP) is examined as a promising redox modulation medium and highly selective anti-cancer therapeutic modality featuring dynamically varying receptor targets and minimized drug resistance against aggressive cancers.

Dual Role of Fibroblasts Educated by Tumour in Cancer Behavior and Therapeutic Perspectives

Tumours are complex systems with dynamic interactions between tumour cells, non-tumour cells, and extracellular components that comprise the tumour microenvironment (TME). The majority of TME's cells are cancer-associated fibroblasts (CAFs), which are crucial in extracellular matrix (ECM) construction, tumour metabolism, immunology, adaptive chemoresistance, and tumour cell motility. CAF subtypes have been identified based on the expression of protein markers. CAFs may act as promoters or suppressors in tumour cells depending on a variety of factors, including cancer stage. Indeed, CAFs have been shown to promote tumour growth, survival and spread, and secretome changes, but they can also slow tumourigenesis at an early stage through mechanisms that are still poorly understood. Stromal-cancer interactions are governed by a variety of soluble factors that determine the outcome of the tumourigenic process. Cancer cells release factors that enhance the ability of fibroblasts to secrete multiple tumour-promoting chemokines, acting on malignant cells to promote proliferation, migration, and invasion. This crosstalk between CAFs and tumour cells has given new prominence to the stromal cells, from being considered as mere physical support to becoming key players in the tumour process. Here, we focus on the concept of cancer as a non-healing wound and the relevance of chronic inflammation to tumour initiation. In addition, we review CAFs heterogeneous origins and markers together with the potential therapeutic implications of CAFs "re-education" and/or targeting tumour progression inhibition.

NETWORK DIFFERENTIAL CONNECTIVITY ANALYSIS

Identifying differences in networks has become a canonical problem in many biological applications. Existing methods try to accomplish this goal by either directly comparing the estimated structures of two networks, or testing the null hypothesis that the covariance or inverse covariance matrices in two populations are identical. However, estimation approaches do not provide measures of uncertainty, e.g., p-values, whereas existing testing approaches could lead to misleading results, as we illustrate in this paper. To address these shortcomings, we propose a qualitative hypothesis testing framework, which tests whether the connectivity structures in the two networks are the same. our framework is especially appropriate if the goal is to identify nodes or edges that are differentially connected. No existing approach could test such hypotheses and provide corresponding measures of uncertainty. Theoretically, we show that under appropriate conditions, our proposal correctly controls the type-I error rate in testing the qualitative hypothesis. Empirically, we demonstrate the performance of our proposal using simulation studies and applications in cancer genomics.

Tumor microenvironment in non-melanoma skin cancer resistance to photodynamic therapy

Non-melanoma skin cancer has recently seen an increase in prevalence, and it is estimated that this grow will continue in the coming years. In this sense, the importance of therapy effectiveness has increased, especially photodynamic therapy. Photodynamic therapy has attracted much attention as a minimally invasive, selective and repeatable approach for skin cancer treatment and prevention. Although its high efficiency, this strategy has also faced problems related to tumor resistance, where the tumor microenvironment has gained a well-deserved role in recent years. Tumor microenvironment denotes a wide variety of elements, such as cancer-associated fibroblasts, immune cells, endothelial cells or the extracellular matrix, where their interaction and the secretion of a wide diversity of cytokines. Therefore, the need of designing new strategies targeting elements of the tumor microenvironment to overcome the observed resistance has become evident. To this end, in this review we focus on the role of cancer-associated fibroblasts and tumor-associated macrophages in the resistance to photodynamic therapy. We are also exploring new approaches consisting in the combination of new and old drugs targeting these cells with photodynamic therapy to enhance treatment outcomes of non-melanoma skin cancer.

TGFβ2 is a Prognostic Biomarker for Gastric Cancer and is Associated With Methylation and Immunotherapy Responses

TGFβ signaling plays a key role in cancer progression and by shaping tumor architecture and inhibiting the anti-tumor activity of immune cells. It was reported that high expression of TGFβ can promote the invasion and metastasis of cancer cells in a variety of tumors. However, there are few studies on TGFβ2 and its methylation in gastric cancer. We analyzed the Harbin Medical University Cancer Hospital (HMUCH) sequencing data and used public data to explore the potential function and prognostic value of TGFβ2 and its methylation in gastric cancer. In this study, we used the ssGSEA algorithm to quantify 23 methylation sites related to TGFβ2. Survival analysis showed that high expression of TGFβ2 and hypomethylation levels of TGFβ2 were negative factors in the prognosis of gastric cancer. Functional enrichment analysis of methylation revealed that methylation of different TGFβ2 methylation scores was mainly involved in energy metabolism, extracellular matrix formation and cell cycle regulation. In the gastric cancer microenvironment TGFβ2 was associated with high levels of multiple immune cell infiltration and cytokine expression, and high TGFβ2 expression was significantly and positively correlated with stemness markers, stromalscore and EMT. Gene set enrichment analysis also revealed an important role of TGFβ2 in promoting EMT. In addition, we discussed the relationship between TGFβ2 and immunotherapy. The expression of PD-1, PD-L1 and CTLA-4 was elevated in the TGFβ2 high expression group. Also when TGFβ2 was highly expressed, the responsiveness of immune checkpoint blockade (ICB) was significantly enhanced. This indicates that TGFβ2 may become an indicator for predicting the efficacy of immunosuppressive agents and a potential target for immunotherapy.

Combined Interaction of Cellular and Extracellular Components Causes Genetic Cascade Activation in Breast Cancer Metastasis

Breast cancer (BC) consists of malignant cells as well as surrounding non-malignant cells-Fibroblasts, macrophages, endothelial cells, lymphocytes, neutrophils, mesenchymal stem cells, and extracellular matrix (ECM). This surrounding stroma is referred to as the Breast Tumor Microenvironment (BTME). The components of BTME interact with cancerous breast cells for the promotion of BC. The reciprocal cross-talk between BTME and neoplastic breast cells, through the secretion of chemicals, growth factors and chemokines, may lead to cell proliferation, migration, metastasis as well as immune response suppression. Multiple genetic loci, in association with stromal components, are linked to immunological stimuli to induce BC in ductal cells. These genes participate in tumor activation pathways and promote carcinogenesis via Fibroblast, Leukocyte, and Endothelial Cells-mediated responses. The collaborative effect of the cellular components and BTME-associated genes plays vital role in tumor initiation and metastasis of breast cells. This process involves genes which cause degenerative changes in ECM leading to Epithelial-Mesenchymal Transitions (EMT), which finally causes metastatic BC. This shows that metastatic breast cancer results from combined activation of different cellular and extracellular components and their activity is primarily controlled by activation of genetic cascade. These components work simultaneously to cause metastatic BC.

Loss of function of BRCA1 promotes EMT in mammary tumors through activation of TGFβR2 signaling pathway

BRCA1 deficient breast cancers are aggressive and chemoresistant due, in part, to their enrichment of cancer stem cells that can be generated from carcinoma cells by an epithelial-mesenchymal transition (EMT). We previously discovered that BRCA1 deficiency activates EMT in mammary tumorigenesis. How BRCA1 controls EMT and how to effectively target BRCA1-deficient cancers remain elusive. We analyzed murine and human tumors and identified a role for Tgfβr2 in governing the molecular aspects of EMT that occur with Brca1 loss. We utilized CRISPR to delete Tgfβr2 and specific inhibitors to block Tgfβr2 activity and followed up with the molecular analysis of assays for tumor growth and metastasis. We discovered that heterozygous germline deletion, or epithelia-specific deletion of Brca1 in mice, activates Tgfβr2 signaling pathways in mammary tumors. BRCA1 depletion promotes TGFβ-mediated EMT activation in cancer cells. BRCA1 binds to the TGFβR2 locus to repress its transcription. Targeted deletion or pharmaceutical inhibition of Tgfβr2 in Brca1-deficient tumor cells reduces EMT and suppresses tumorigenesis and metastasis. BRCA1 and TGFβR2 expression levels are inversely related in human breast cancers. This study reveals for the first time that a targetable TGFβR signaling pathway is directly activated by BRCA1-deficiency in the induction of EMT in breast cancer progression.

Exploiting Canonical TGFβ Signaling in Cancer Treatment

Transforming growth factor β (TGFβ) is a pleiotropic cytokine that plays critical roles to define cancer cell phenotypes, construct the tumor microenvironment, and suppress anti-tumor immune responses. As such, TGFβ is a lynchpin for integrating cancer cell intrinsic pathways and communication among host cells in the tumor and beyond that together affect responses to genotoxic, targeted, and immune therapy. Despite decades of preclinical and clinical studies, evidence of clinical benefit from targeting TGFβ in cancer remains elusive. Here, we review the mechanisms by which TGFβ acts to oppose successful cancer therapy, the reported prognostic and predictive value of TGFβ biomarkers, and the potential impact of inhibiting TGFβ in precision oncology. Paradoxically, the diverse mechanisms by which TGFβ impedes therapeutic response are a principal barrier to implementing TGFβ inhibitors because it is unclear which TGFβ mechanism is functional in which patient. Companion diagnostic tools and specific biomarkers of TGFβ targeted biology will be the key to exploiting TGFβ biology for patient benefit.

Organotypic 3D decellularized matrix tumor spheroids for high-throughput drug screening

Decellularized extracellular matrix (dECM) is emerging as a valuable tool for generating 3D in vitro tumor models that better recapitulate tumor-stroma interactions. However, the development of dECM-3D heterotypic microtumors exhibiting a controlled morphology is yet to be materialized. Precisely controlling microtumors morphologic features is key to avoid an inaccurate evaluation of therapeutics performance during preclinical screening. To address this, herein we employed ultra-low adhesion surfaces for bioengineering organotypic 3D metastatic breast cancer-fibroblast models enriched with dECM microfibrillar fragments, as a bottom-up strategy to include major matrix components and their associated biomolecular cues during the early stages of 3D microtissue spheroids assembly, simulating pre-existing ECM presence in the in vivo setting. This biomimetic approach enabled the self-assembly of dECM-3D tumor-stroma spheroids with tunable size and reproducible morphology. Along time, dECM enriched and stroma-rich microtumors exhibited necrotic core formation, secretion of key biomarkers and higher cancer-cell specific resistance to different chemotherapeutics in comparison to standard spheroids. Exometabolomics profiling of dECM-Spheroid in vitro models further identified important breast cancer metabolic features including glucose/pyruvate consumption and lactate excretion, which suggest an intense glycolytic activity, recapitulating major hallmarks of the native microenvironment. Such organotypic dECM-enriched microtumors overcome the morphologic variability generally associated with cell-laden dECM models, while providing a scalable testing platform that can be foreseeable leveraged for high-throughput screening of candidate therapeutics.

Transformable Honeycomb-Like Nanoassemblies of Carbon Dots for Regulated Multisite Delivery and Enhanced Antitumor Chemoimmunotherapy

Tumor fibrotic stroma forms complex barriers for therapeutic nanomedicine. Although nanoparticle vehicles are promising in overcoming biological barriers for drug delivery, fibrosis causes hypoxia, immunosuppression and limited immunocytes infiltration, and thus reduces antitumor efficacy of nanosystems. Herein, we report the development of cancer-associated fibroblasts (CAFs) responsive honeycomb-like nanoassemblies of carbon dots (CDs) to spatially program the delivery of multiple therapeutics for enhanced antitumor chemoimmunotherapy. Doxorubicin (DOX) and immunotherapeutic enhancer (Fe ions) are immobilized on the surface of CDs, whereas tumor microenvironment modifier (losartan, LOS) is encapsulated within the mesopores. The drugs-loaded nanoassemblies disassociate into individual CDs to release LOS to mitigate stroma and hypoxia in response to CAFs. The individual CDs carrying DOX and Fe ion efficiently penetrate deep into tumor to trigger intensified immune responses. Our in vitro and in vivo studies show that the nanoassemblies exhibit effective T cells infiltration, tumor growth inhibition and lung metastasis prevention, thereby providing a therapeutic platform for desmoplasia solid tumor.

Identification of Key Modules and Hub Genes of Annulus Fibrosus in Intervertebral Disc Degeneration

Background: Intervertebral disc degeneration impairs the quality of patients lives. Even though there has been development of many therapeutic strategies, most of them remain unsatisfactory due to the limited understanding of the mechanisms that underlie the intervertebral disc degeneration. Questions/purposes: This study is meant to identify the key modules and hub genes related to the annulus fibrosus in intervertebral disc degeneration (IDD) through: (1) constructing a weighted gene co-expression network; (2) identifying key modules and hub genes; (3) verifying the relationships of key modules and hub genes with IDD; and (4) confirming the expression pattern of hub genes in clinical samples. Methods: The Gene Expression Omnibus provided 24 sets of annulus fibrosus microarray data. Differentially expressed genes between the annulus fibrosus of degenerative and non-degenerative intervertebral disc samples have gone through the Gene Ontology (GO) and pathway analysis. The construction of a gene network and classification of genes into different modules were conducted through performing Weighted Gene Co-expression Network Analysis. The identification of modules and hub genes that were most related to intervertebral disc degeneration was proceeded. In order to verify the relationships of the module and hub genes with intervertebral disc degeneration, Ingenuity Pathway Analysis was operated. Clinical samples were adopted to help verify the hub gene expression profile. Results: One thousand one hundred ninety differentially expressed genes were identified. Terms and pathways associated with intervertebral disc degeneration were presented by GO and pathway analysis. The construction of a Weighted Gene Coexpression Network was completed and clustering differentially expressed genes into four modules was also achieved. The module with the lowest P-value and the highest absolute correlation coefficient was selected and its relationship with intervertebral disc degeneration was confirmed by Ingenuity Pathway Analysis. The identification of hub genes and the confirmation of their expression profile were also realized. Conclusions: This study generated a comprehensive overview of the gene networks underlying annulus fibrosus in intervertebral disc degeneration. Clinical Relevance: Modules and hub genes identified in this study are highly associated with intervertebral disc degeneration, and may serve as potential therapeutic targets for intervertebral disc degeneration.

Cancer-Associated Fibroblasts: Understanding Their Heterogeneity

The tumor microenvironment (TME) plays a critical role in tumor progression. Among its multiple components are cancer-associated fibroblasts (CAFs) that are the main suppliers of extracellular matrix molecules and important contributors to inflammation. As a source of growth factors, cytokines, chemokines and other regulatory molecules, they participate in cancer progression, metastasis, angiogenesis, immune cell reprogramming and therapeutic resistance. Nevertheless, their role is not fully understood, and is sometimes controversial due to their heterogeneity. CAFs are heterogeneous in their origin, phenotype, function and presence within tumors. As a result, strategies to target CAFs in cancer therapy have been hampered by the difficulties in better defining the various populations of CAFs and by the lack of clear recognition of their specific function in cancer progression. This review discusses how a greater understanding of the heterogeneous nature of CAFs could lead to better approaches aimed at their use or at their targeting in the treatment of cancer.

Lipoproteins and the Tumor Microenvironment

The tumor microenvironment (TME) plays a key role in enhancing the growth of malignant tumors and thus contributing to "aggressive phenotypes," supporting sustained tumor growth and metastasis. The precise interplay between the numerous components of the TME that contribute to the emergence of these aggressive phenotypes is yet to be elucidated and currently under intense investigation. The purpose of this article is to identify specific role(s) for lipoproteins as part of these processes that facilitate (or oppose) malignant growth as they interact with specific components of the TME during tumor development and treatment. Because of the scarcity of literature reports regarding the interaction of lipoproteins with the components of the tumor microenvironment, we were compelled to explore topics that were only tangentially related to this topic, to ensure that we have not missed any important concepts.

A System Biology-Based Approach for Designing Combination Therapy in Cancer Precision Medicine

In this paper, we have used an agent-based stochastic tumor growth model and presented a mathematical and theoretical perspective to cancer therapy. This perspective can be used to theoretical study of precision medicine and combination therapy in individuals. We have conducted a series of in silico combination therapy experiments. Based on cancer drugs and new findings of cancer biology, we hypothesize relationships between model parameters which in some cases represent individual genome characteristics and cancer drugs, i.e., in our approach, therapy players are delegated by biologically reasonable parameters. In silico experiments showed that combined therapies are more effective when players affect tumor via different mechanisms and have different physical dimensions. This research presents for the first time an algorithm as a theoretical viewpoint for the prediction of effectiveness and classification of therapy sets.

Distinct prognostic values and antitumor effects of tumor growth factor β1 and its receptors in gastric cancer

Gastric cancer (GC) is one of the most common malignancies and is the second leading cause of cancer-associated mortality world-wide. In the present study, the prognostic value and antitumor effects of transforming growth factor β1 (TGFβ1) and its receptors in GC were explored. The online Kaplan-Meier plotter database was used to investigate the prognostic values of TGFβ1 and its receptors. The present study demonstrated that low mRNA expression levels of TGFβ1 and its 3 receptors, transforming growth factor β1 (TGFβR1), TGFβR2 and TGFβR3, was associated with improved overall survival time in patients with GC. Cell Counting Kit-8 and Transwell assays were used to confirm the effects of TGFβ1, TGFβR1, TGFβR2 and TGFβR3 on the proliferation, migration and invasiveness of the AGS and MKN45 GC cell lines. It was found that the knockdown of these genes blocked cell proliferation, migration and invasion in GC cells. To the best of our knowledge, the present study is the first to determine the role of TGFβR1 and TGFβR3 in GC cells. The results indicate that in addition to TGFβ1 and TGFβR2, TGFβR1 also plays a specific role in the occurrence and development of tumors. Thus, these markers may be considered as potential prognostic indicators in human GC. The findings of the present study indicate that not only TGFβ1 and TGFβR2, but also TGFβR1 is involved in the progression of GC. The findings of the present study provide new ideas and approaches for the treatment of patients with GC.

Dualism of FGF and TGF-β Signaling in Heterogeneous Cancer-Associated Fibroblast Activation with ETV1 as a Critical Determinant

Heterogeneity of cancer-associated fibroblasts (CAFs) can result from activation of distinct signaling pathways. We show that in primary human dermal fibroblasts (HDFs), fibroblast growth factor (FGF) and transforming growth factor β (TGF-β) signaling oppositely modulate multiple CAF effector genes. Genetic abrogation or pharmacological inhibition of either pathway results in induction of genes responsive to the other, with the ETV1 transcription factor mediating the FGF effects. Duality of FGF/TGF-β signaling and differential ETV1 expression occur in multiple CAF strains and fibroblasts of desmoplastic versus non-desmoplastic skin squamous cell carcinomas (SCCs). Functionally, HDFs with opposite TGF-β versus FGF modulation converge on promoting cancer cell proliferation. However, HDFs with increased TGF-β signaling enhance invasive properties and epithelial-mesenchymal transition (EMT) of SCC cells, whereas HDFs with increased FGF signaling promote macrophage infiltration. The findings point to a duality of FGF versus TGF-β signaling in distinct CAF populations that promote cancer development through modulation of different processes.

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FGF and TGF-β signaling exert opposite control over multiple CAF effector genes

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ETV1 transcription factor mediates FGF effects and suppresses those of TGF-β

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Modulation of either pathway leads to different tumor-promoting CAF populations

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TGF-β-activated CAFs promote EMT, but FGF-activated CAFs increase inflammation

Connexin 43 Modulates the Cellular Resistance to Paclitaxel via Targeting β-Tubulin in Triple-Negative Breast Cancer

Background

Triple-negative breast cancer has become an intricate part and hotspot in the clinical and experimental research. Connexins, serving as functional proteins in gap junctions, play an important role in tumorigenesis, cell proliferation and metastasis.

Methods

We constructed and employed the Connexin 43 (Cx43) overexpression lentiviral vectors and Cx43 siRNA in paclitaxel-treated MDA-MB-231 cells. We performed the experiments of clonal formation and flow cytometry to gauge the effect of paclitaxel on cellular behaviors and immunofluorescence and subsequent quantitative RT-PCR and Western blot to examine the expression of genes and corresponding proteins. Experiments of scrape loading/dye transfer were utilized to explore the gap junctions. The targets of Cx43 were identified via the experiments of co-immunoprecipitation (Co-IP), GST pull-down assays and proximal ligation assay (PLA).

Results

The results showed that Cx43 hindered cell proliferation and promoted apoptosis in the paclitaxel-treated MDA-MB-231 cells. Overexpressed Cx43 suppressed the expression of resistance genes such as BRCP, Txr-1, α-tubulin and β-tubulin and promoted the expression of apoptosis gene as TSP-1 and Bcl-2. Cx43 was also positively related to ITGα9 and negatively related to ITGαV and ITGα11. The gap junctions altered magnificently under different expressions of Cx43, which indicated that Cx43 could promote the number of intercellular gap junctions. The immunofluorescent experiment revealed that both of Cx43 and β-tubulin were mainly localized in the cytoplasm. The assays of Co-IP and GST pull-down demonstrated that there existed a direct interaction between Cx43 and β-tubulin. Furthermore, the result of PLA also showed that Cx43 interacts with β-tubulin in MDA-MB-231 cells.

Conclusion

Overexpression of Cx43 could modulate the cellular resistance to paclitaxel via targeting β-tubulin in triple-negative breast cancer.

Novel Immunotherapy Combinations

PURPOSE OF REVIEW

The last decade witnessed an explosion in immunotherapeutic agent approvals for various malignancies. The success of immune checkpoint inhibitors (CTLA-4 and PD-1/PD-L1) in melanoma quickly sprung to other cancer types and are considered the emerging face of oncology.

RECENT FINDINGS

Antibodies to CTLA-4 were first to enter the field, quickly followed by PD-1/PD-L1 inhibitors. Combination anti-CTLA4 and anti-PD-1/PD-L1 therapies were investigated, and after demonstrating improved responses, rapidly gained approval. Certain tumor types previously considered non-immunogenic also demonstrated durable responses which has been a remarkable discovery. However, not all tumor types respond to immunotherapies and it is widely recognized that tumor-specific immune inflammatory status predicts the best responders. Ongoing translational work indicates specific upregulation in additional immune checkpoints that circumvent response to anti-CTLA4 and anti-PD-1/PD-L1 antibodies. Here, we provide a comprehensive review of promising therapies on the horizon with unique combinations designed to overcome resistance or expand the pool of treatment responders.

Phosphodiesterase 5 (PDE5) Is Highly Expressed in Cancer-Associated Fibroblasts and Enhances Breast Tumor Progression

The overexpression of phosphodiesterase (PDE) 5 is frequently found in various human cancers, such as those of the breast. However, PDE5’s role in the tumor microenvironment is still unknown. As PDE5 represents a high-value therapeutic target, we investigated whether the expression and function of PDE5 in breast cancer-associated fibroblasts (CAFs) may be clinically relevant to malignant progression. PDE5 expression was increased in human breast cancer stroma compared with normal stroma and was correlated to a shorter overall survival. Treatment of CAFs, isolated from breast tumor biopsies, with selective PDE5 inhibitors inhibited their proliferation, motility, and invasiveness, and negatively controlled tumor–stroma interactions in both ‘in vitro’ and ‘in vivo’ models. PDE5 stable overexpression transformed immortalized mouse embryonic fibroblasts (MEFs) towards an activated fibroblast phenotype, impacting their intrinsic characteristics and paracrine effects on breast cancer cell growth and migration through an enhanced production of the C-X-C motif chemokine 16 (CXCL16). On the other hand, CAF exposure to PDE5 inhibitors was associated with reduced CXCL16 expression and secretion. Importantly, CXCL16 levels in breast cancer stroma showed a strong correlation with PDE5 levels and poor patient outcomes. In conclusion, PDE5 is overexpressed in breast cancer stroma, enhances the tumor-stimulatory activities of fibroblasts, and impacts clinical outcomes; thus, we propose this enzyme as an attractive candidate for prognosis and a potential target for treatments in breast cancer patients.

Paracrine recruitment and activation of fibroblasts by c-Myc expressing breast epithelial cells through the IGFs/IGF-1R axis

Fibroblasts are among the most abundant stromal cells in the tumor microenvironment (TME), progressively differentiating into activated, motile, myofibroblast-like, protumorigenic cells referred to as Cancer-Associated Fibroblasts (CAFs). To investigate the mechanisms by which epithelial cells direct this transition, the early stages of tumorigenesis were exemplified by indirect cocultures of WI-38 or human primary breast cancer fibroblasts with human mammary epithelial cells expressing an inducible c-Myc oncogene (MCF10A-MycER). After c-Myc activation, the conditioned medium (CM) of MCF10A-MycER cells significantly enhanced fibroblast activation and mobilization. As this was accompanied by decreased insulin-like growth factor binding protein-6 (IGFBP-6) and increased insulin-like growth factor-1 and IGF-II (IGF-I, IGF-II) in the CM, IGFs were investigated as key chemotactic factors. Silencing IGFBP-6 or IGF-I or IGF-II expression in epithelial cells or blocking Insulin-like growth factor 1 receptor (IGF-1R) activity on fibroblasts significantly altered fibroblast mobilization. Exposure of WI-38 fibroblasts to CM from induced MCF10A-MycER cells or to IGF-II upregulated FAK phosphorylation on Tyr³⁹⁷ , as well as the expression of α-smooth muscle actin (α-SMA), features associated with CAF phenotype and increased cell migratory/invasive behavior. In three-dimensional (3D)-organotypic assays, WI-38 or human primary fibroblasts, preactivated with either CM from MCF10A-MycER cells or IGFs, resulted in a permissive TME that enabled nontransformed MCF10A matrix invasion. This effect was abolished by inhibiting IGF-1R activity. Thus, breast epithelial cell oncogenic activation and stromal fibroblast transition to CAFs are linked through the IGFs/IGF-1R axis, which directly promotes TME remodeling and increases tumor invasion.

Down-regulation of CCL17 in cancer-associated fibroblasts inhibits cell migration and invasion of breast cancer through ERK1/2 pathway

Objective

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment are involved in cancer development and progression, including breast cancer (BC). Up-regulation of CCL17 was observed in BC and predicted a decrease in overall survival, suggesting an important role of CCL17 in BC development. Nonetheless, little is known about the role of CCL17 in the interaction between CAFs and BC.

Materials and methods

Real-time quantitative PCR, Western blot, and enzyme-linked immunosorbent assay were performed to examine C-C motif chemokine ligand 17 (CCL17) and C-C motif chemokine receptor 4 (CCR4) levels in BC tissues and CAFs. Cell proliferation, migration, and invasion of CAFs co-cultured with or without BC cell lines were measured by Cell Counting Kit-8 and Transwell analysis. Expression of CCL17, CCR4, dual specificity phosphatase 6 (DUSP6), matrix metallopeptidase 13 (MMP13), extracellular signal-regulated kinase (ERK) 1/2, and phosphor-ERK1/2 (p-ERK1/2) in BC cell lines co-cultured with or without CAFs was measured by Western blotting.

Results

We found that BC tissues and CAFs demonstrated higher levels of CCL17 compared with adjacent-normal breast tissues and adjacent-normal fibroblasts (NFs), respectively. CCL17 expression is correlated with lymph nodes, TNM stage and tumor size of BC patients. CCL17 knockdown significantly inhibited CCL17 release, CCR4 expression, and the cell proliferation of CAFs, while CCL17 overexpression demonstrated an inverse effect in NFs. Co-culture with CAFs induced the increases in cell proliferation, migration, invasion, and the expression of CCL17, CCR4, MMP13, and p-ERK1/2 in MCF-7 and MDA-MB-231 cells were markedly reversed by CCL17 knockdown in CAFs. Meanwhile, co-culture with NFs induced the malignant phenotype of MCF-7 cells was markedly enhanced by CCL17 overexpression in NFs. Moreover, DUSP6, a negative regulator of ERK1/2, was dose-dependent decrease in response to recombinant CCL17 and inhibited cell migration, invasion, MMP13 expression, and ERK1/2 activation in MCF-7 cells.

Conclusion

The findings of this study suggest that CCL17 may function as a novel biomarker as well as potential therapeutic target against BC and CAF-secreted CCL17 promotes BC cell migration and invasion through the DUSP6-dependent ERK1/2 pathway.

Effects of metformin and phenformin on apoptosis and epithelial-mesenchymal transition in chemoresistant rectal cancer

Recurrence and chemoresistance in colorectal cancer remain important issues for patients treated with conventional therapeutics. Metformin and phenformin, previously used in the treatment of diabetes, have been shown to have anticancer effects in various cancers, including breast, lung and prostate cancers. However, their molecular mechanisms are still unclear. In this study, we examined the effects of these drugs in chemoresistant rectal cancer cell lines. We found that SW837 and SW1463 rectal cancer cells were more resistant to ionizing radiation and 5‐fluorouracil than HCT116 and LS513 colon cancer cells. In addition, metformin and phenformin increased the sensitivity of these cell lines by inhibiting cell proliferation, suppressing clonogenic ability and increasing apoptotic cell death in rectal cancer cells. Signal transducer and activator of transcription 3 and transforming growth factor‐β/Smad signaling pathways were more activated in rectal cancer cells, and inhibition of signal transducer and activator of transcription 3 expression using an inhibitor or siRNA sensitized rectal cancer cells to chemoresistant by inhibition of the expression of antiapoptotic proteins, such as X‐linked inhibitor of apoptosis, survivin and cellular inhibitor of apoptosis protein 1. Moreover, metformin and phenformin inhibited cell migration and invasion by suppression of transforming growth factor β receptor 2‐mediated Snail and Twist expression in rectal cancer cells. Therefore, metformin and phenformin may represent a novel strategy for the treatment of chemoresistant rectal cancer by targeting signal transducer and activator of transcription 3 and transforming growth factor‐β/Smad signaling.

miR-665 expression predicts poor survival and promotes tumor metastasis by targeting NR4A3 in breast cancer

Cancer metastasis is the main cause of death in breast cancer (BC) patients. Therefore, prediction and treatment of metastasis is critical for enhancing the survival of BC patients. In this study, we aimed to identify biomarkers that can predict metastasis of BC and elucidate the underlying mechanism of the functional involvement of such markers in metastasis. miRNA expression profile was analyzed using a custom microarray system in 422 BC tissues. The relationship between the upregulated miR-665, metastasis and survival of BC was analyzed and verified in another set of 161 BC samples. The biological function of miR-665 in BC carcinogenesis was explored with in vitro and in vivo methods. The target gene of miR-665 and its signaling cascade were also analyzed. There are 399 differentially expressed miRNAs between BC and noncancerous tissues, of which miR-665 is the most upregulated miRNA in the BC tissues compared with non-tumor breast tissues (P < 0.001). The expression of miR-665 predicts metastasis and poor survival in 422 BC patients, which is verified in another 161 BC patients and 2323 BC cases from online databases. Ectopic miR-665 expression promotes epithelial–mesenchymal transition (EMT), proliferation, migration and invasion of BC cells, and increases tumor growth and metastasis of BC in mice. Bioinformatics, luciferase assay and other methods showed that nuclear receptor subfamily 4 group A member 3 (NR4A3) is a target of miR-665 in BC. Mechanistically, we demonstrated that miR-665 promotes EMT, invasion and metastasis of BC via inhibiting NR4A3 to activate MAPK/ERK kinase (MEK) signaling pathway. Our study demonstrates that miR-665 upregulation is associated with metastasis and poor survival in BC patients, and mechanistically, miR-665 enhances progression of BC via NR4A3/MEK signaling pathway. This study provides a new potential prognostic biomarker and therapeutic target for BC patients.

Impact of endocrine disruptor hexachlorobenzene on the mammary gland and breast cancer: The story thus far

Breast cancer incidence is increasing globally and exposure to endocrine disruptors has gained importance as a potential risk factor. Hexachlorobenzene (HCB) was once used as a fungicide and, despite being banned, considerable amounts are still released into the environment. HCB acts as an endocrine disruptor in thyroid, uterus and mammary gland and was classified as possibly carcinogenic to human. This review provides a thorough analysis of results obtained in the last 15 years of research and evaluates data from assays in mammary gland and breast cancer in diverse animal models. We discuss the effects of environmentally relevant HCB concentrations on the normal mammary gland and different stages of carcinogenesis, and attempt to elucidate its mechanisms of action at molecular level. HCB weakly binds to the aryl hydrocarbon receptor (AhR), activating both membrane (c-Src) and nuclear pathways. Through c-Src stimulation, AhR signaling interacts with other membrane receptors including estrogen receptor-α, insulin-like growth factor-1 receptor, epidermal growth factor receptor and transforming growth factor beta 1 receptors. In this way, several pathways involved in mammary morphogenesis and breast cancer development are modified, inducing tumor progression. HCB thus stimulates epithelial cell proliferation, preneoplastic lesions and alterations in mammary gland development as well as neoplastic cell migration and invasion, metastasis and angiogenesis in breast cancer. In conclusion, our findings support the hypothesis that the presence and bioaccumulation of HCB in high-fat tissues and during highly sensitive time windows such as pregnancy, childhood and adolescence make exposure a risk factor for breast tumor development.

Oncogenic Signaling in Tumorigenesis and Applications of siRNA Nanotherapeutics in Breast Cancer

Overexpression of oncogenes and cross-talks of the oncoproteins-regulated signaling cascades with other intracellular pathways in breast cancer could lead to massive abnormal signaling with the consequence of tumorigenesis. The ability to identify the genes having vital roles in cancer development would give a promising therapeutics strategy in combating the disease. Genetic manipulations through siRNAs targeting the complementary sequence of the oncogenic mRNA in breast cancer is one of the promising approaches that can be harnessed to develop more efficient treatments for breast cancer. In this review, we highlighted the effects of major signaling pathways stimulated by oncogene products on breast tumorigenesis and discussed the potential therapeutic strategies for targeted delivery of siRNAs with nanoparticles in suppressing the stimulated signaling pathways.

The effects and the mechanisms of autophagy on the cancer-associated fibroblasts in cancer

Cancer-associated fibroblasts (CAFs) plays an essential role in cancer cell growth, metabolism and immunoreaction. Autophagy is an intracellular self-degradative process that balances cell energy source and regulates tissue homeostasis. Targeting autophagy has gained interest with multiple preclinical and clinical trials, such as the pharmacological inhibitor chloroquine or the inducer rapamycin, especially in exploiting its ability to modulate the secretory capability of CAFs to enhance drug delivery or inhibit it to prevent its influence on cancer cell chemoresistance. In this review, we summarize the reports on autophagy in cancer-associated fibroblasts by detailing the mechanism and role of autophagy in CAFs, including the hypoxic-autophagy positive feedback cycle, the metabolic cross-talk between CAFs and tumors induced by autophagy, CAFs secreted cytokines promote cancer survival by secretory autophagy, CAFs autophagy-induced EMT, stemness, senescence and treatment sensitivity, as well as the research of antitumor chemicals, miRNAs and lncRNAs. Additionally, we discuss the evidence of molecules in CAFs that are relevant to autophagy and the contribution to sensitive treatments as a potential target for cancer treatment.

Suppressive effect of exogenous miR-16 and miR-34a on tumorigenesis of breast cancer cells

Recent investigations have shown tumor-suppressive roles for miR-16 and miR-34a. They also share some features in regard to targeting cancer cell signaling pathways which they control. Therefore, in this study, we aimed to further scrutinize whether exogenous induction of mature miR-34a and miR-16 can collaborate in breast tumor suppression. MDA-MB-231 and SK-BR-3 human breast cancer cell lines were cultured and transfected twice with hsa-miR-16-5p and hsa-miR-34a-5p mimics individually or in combination. The cells were analyzed for apoptosis rate and cell cycle indices by flow cytometry. Also, the expression of several invasion and the epithelial-mesenchymal transition markers was evaluated at gene and protein levels by quantitative real-time polymerase chain reaction and western blot analysis, respectively. Assessment of invasiveness and migratory potential of the transfected cells was performed using three-dimensional spheroid formation and wound-healing assay, respectively. In both cell lines, miR-16 and miR-34a induced apoptosis and cell-cycle arrest and also suppressed invasion and migration. Some of these effects, like cell-cycle arrest and induction of apoptosis, were significantly higher when using both microRNAs than when using them individually for transfection of the cells. Our results are indicating that miR-16 and miR-34a can collaborate in breast tumor suppression.

Curcumin Suppresses Hepatic Stellate Cell-Induced Hepatocarcinoma Angiogenesis and Invasion through Downregulating CTGF

Microenvironment plays a vital role in tumor progression; we focused on elucidating the role of hepatic stellate cells (HSCs) in hepatocarcinoma (HCC) aggressiveness and investigated the potential protective effect of curcumin on HSC-driven hepatocarcinoma angiogenesis and invasion. Our data suggest that HSCs increase HCC reactive oxygen species (ROS) production to upregulate hypoxia-inducible factor-1α (HIF-1α) expression to promote angiogenesis, epithelial to mesenchymal transition (EMT) process and invasion. And HSCs could secrete soluble factors, such as interleukin-6 (IL-6), vascular endothelial cell growth factor (VEGF), and stromal-derived factor-1 (SDF-1) to facilitate HCC progression. Curcumin could significantly suppress the above HSC-induced effects in HCC and could abrogate ROS and HIF-1α expression in HCC. HIF-1α or connective tissue growth factor (CTGF) knockdown could abolish the aforementioned curcumin affection. Moreover, CTGF is a downstream gene of HIF-1α. In addition, nuclear factor E2-related factor 2 (Nrf2) and glutathione (GSH) are involved in curcumin protection of HCC. These data indicate that curcumin may induce ROS scavenging by upregulating Nrf2 and GSH, thus inhibiting HIF-1α stabilization to suppress CTGF expression to exhibit its protection on HCC. Curcumin has a promising therapeutic effect on HCC. CTGF is responsible for curcumin-induced protection in HCC.

Deregulated MicroRNAs in Cancer-Associated Fibroblasts from Front Tumor Tissues of Lung Adenocarcinoma as Potential Predictors of Tumor Promotion

Cancer-associated fibroblasts (CAFs) are the main component of the tumor stroma and promote tumor progression through several mechanisms. Recent evidence indicates that small noncoding RNAs, microRNAs (miRNAs), play key roles in CAF tumor-promoting properties; however, the role of miRNAs in lung cancer-associated fibroblasts remains poorly defined. We characterized the differential miRNA expression profile of fibroblasts isolated from matched tumor front (F-CAFs), inner tumor (In-CAFs), and normal adjacent (NFs) tissues from four lung adenocarcinoma patients (ADs) using microarray analysis. Proliferation and invasion assays of A549 human lung cancer cells in the presence of conditioned medium from F-CAFs, In-CAFs or NFs were performed to assess tumorigenic properties. Ten identified candidate miRNAs in F-CAFs, In-CAFs and NFs from 12 ADs were then validated by RT-PCR. Both F-CAFs and In-CAFs enhanced the proliferation and invasion of A549 cells compared with NFs; moreover, F-CAFs showed a significantly stronger effect than In-CAFs. RT-PCR validation demonstrated three downregulated miRNAs in F-CAFs compared with NFs (miR-145-3p, miR-299-3p, and miR-505-3p), two in F-CAFs compared with In-CAFs (miR-410-3p and miR-485-5p), but no differentially expressed miRNAs between In-CAFs and NFs. Further target-gene prediction and pathway enrichment analysis indicated that deregulated miRNAs in F-CAFs showed significant associations with "pathways in cancer" (miR-145-3p, miR-299-3p and miR-410-3p), "Wnt signaling pathway" (miR-410-3p and miR-505-3p), and "TGF-beta signaling pathway" (miR-410-3p). Importantly, a tumor-promoting growth factor targeted by those miRNAs, VEGFA, was upregulated in F-CAFs compared with NFs, as judged by RT-PCR. In conclusion, deregulated miRNAs in F-CAFs are potentially associated with CAF tumor-promoting properties.

Cancer Associated Fibroblasts: Naughty Neighbors That Drive Ovarian Cancer Progression

Ovarian cancer is the most lethal gynecologic malignancy, and patient prognosis has not improved significantly over the last several decades. In order to improve therapeutic approaches and patient outcomes, there is a critical need for focused research towards better understanding of the disease. Recent findings have revealed that the tumor microenvironment plays an essential role in promoting cancer progression and metastasis. The tumor microenvironment consists of cancer cells and several different types of normal cells recruited and reprogrammed by the cancer cells to produce factors beneficial to tumor growth and spread. These normal cells present within the tumor, along with the various extracellular matrix proteins and secreted factors, constitute the tumor stroma and can compose 10–60% of the tumor volume. Cancer associated fibroblasts (CAFs) are a major constituent of the tumor microenvironment, and play a critical role in promoting many aspects of tumor function. This review will describe the various hypotheses about the origin of CAFs, their major functions in the tumor microenvironment in ovarian cancer, and will discuss the potential of targeting CAFs as a possible therapeutic approach.