Inflammatory factors of the tumor microenvironment induce plasticity in nontransformed breast epithelial cells: EMT, invasion, and collapse of normally organized breast textures

Chemokine receptors and their ligands in breast cancer: The key roles in progression and metastasis

Chemokines and their receptors are a family of chemotactic cytokines with important functions in the immune response in both health and disease. Their known physiological roles such as the regulation of leukocyte trafficking and the development of immune organs generated great interest when it was found that they were also related to the control of early and late inflammatory stages in the tumor microenvironment. In fact, in breast cancer, an imbalance in the synthesis of chemokines and/or in the expression of their receptors was attributed to be involved in the regulation of disease progression, including invasion and metastasis. Research in this area is progressing rapidly and the development of new agents based on chemokine and chemokine receptor antagonists are emerging as attractive alternative strategies. This chapter provides a snapshot of the different functions reported for chemokines and their receptors with respect to the potential to regulate breast cancer progression.

MiRNAs Overexpression and Their Role in Breast Cancer: Implications for Cancer Therapeutics

MicroRNAs have a plethora of roles in various biological processes in the cells and most human cancers have been shown to be associated with dysregulation of the expression of miRNA genes. MiRNA biogenesis involves two alternative pathways, the canonical pathway which requires the successful cooperation of various proteins forming the miRNA-inducing silencing complex (miRISC), and the non-canonical pathway, such as the mirtrons, simtrons, or agotrons pathway, which bypasses and deviates from specific steps in the canonical pathway. Mature miRNAs are secreted from cells and circulated in the body bound to argonaute 2 (AGO2) and miRISC or transported in vesicles. These miRNAs may regulate their downstream target genes via positive or negative regulation through different molecular mechanisms. This review focuses on the role and mechanisms of miRNAs in different stages of breast cancer progression, including breast cancer stem cell formation, breast cancer initiation, invasion, and metastasis as well as angiogenesis. The design, chemical modifications, and therapeutic applications of synthetic anti-sense miRNA oligonucleotides and RNA mimics are also discussed in detail. The strategies for systemic delivery and local targeted delivery of the antisense miRNAs encompass the use of polymeric and liposomal nanoparticles, inorganic nanoparticles, extracellular vesicles, as well as viral vectors and viruslike particles (VLPs). Although several miRNAs have been identified as good candidates for the design of antisense and other synthetic modified oligonucleotides in targeting breast cancer, further efforts are still needed to study the most optimal delivery method in order to drive the research beyond preclinical studies.

AEBP1 Is One of the Epithelial-Mesenchymal Transition Regulatory Genes in Colon Adenocarcinoma

Epithelial-mesenchymal transition (EMT) is involved in various tumor processes, including tumorigenesis, tumor cell migration and metastasis, tumor stemness, and therapeutic resistance. Therefore, it is important to identify the genes most associated with EMT and develop them as therapeutic targets. In this work, we first analyzed EMT hallmark gene expression profiles among 10,535 pan-cancer samples from The Cancer Genome Atlas (TCGA) and divided them into EMT high and EMT low groups according to the metagene scores. Then, we identified 12 genes that were most associated with high EMT metagene score (R > 0.9) in 329 colon adenocarcinoma (COAD) patients. Among them, only 4 genes (AEBP1, KCNE4, GFPT2, and FAM26E) had statistically significant differences in prognosis (P < 0.05). Next, we selected AEBP1 as a candidate and showed that AEBP1 mRNA levels and EMT biomarkers strongly coexpressed in 329 COAD samples. In addition, AEBP1 was highly expressed and associated with poor clinical outcomes and prognosis in COAD patients. Finally, to explore whether AEBP1-mediated EMT was related to the tumor microenvironment (TME), we examined AEBP1 expression levels at the single-cell levels. Our results showed that AEBP1 levels were extremely high in tumor-associated fibroblasts, which may induce EMT. AEBP1 expression was also positively correlated with the expression of fibroblast biomarkers and also with EMT metascores, suggesting that AEBP1-mediated EMT may be associated with the stimulation of fibroblast activation. Therefore, AEBP1 may be a promising target for EMT inhibition, which reduces cancer metastasis and drug resistance in COAD patients.

Tumor Microenvironment: Involved Factors and Signaling Pathways in Epithelial-Mesenchymal Transition

Context: Metastasis is a main cause of death in patients with cancer, whereby tumor cells withdraw from the primary site of the tumor mass and produce secondary tumor mass in new sites. Primary tumor cells depart collectively and individually to invade closed and distant sites. Evidence Acquisition: This review considers TME-derived factors that actuate signaling pathways to induce epithelial-mesenchymal transition (EMT). National Center for Biotechnology Information (NCBI) was the main resource. Google Scholar and Scopus were other databases for finding articles. Keywords that were inserted into the search box of databases to identify related articles were ‘metastasis’, ‘invasion’, ‘epithelial-mesenchymal transition’, ‘EMT’, ‘tumor microenvironment’, ‘TME’, ‘TME cells’, and ‘signaling pathway in EMT’. Titles and abstracts of the articles were studied to choose the right articles. Finally, 107 articles were selected to study in detail and use as references. Results: EMT is a type of metastasis that deprives epithelial single-cells of their characteristic features and acquires mesenchymal features facilitating the departure from the primary tumor mass. During EMT, cell-adhesion and apical-basal polarity rapture and cells obtain movement capability. The tumor microenvironment (TME) leads EMT through secretion factors and signaling pathways. As a result of activating these pathways, transcription factors that abolish epithelial gene expressions and augment mesenchymal gene expression are induced. Conclusions: In this review, recent research published in TME and EMT fields were highlighted and critically appraised. Effect of factors-derived TME cells on EMT were manifested that propose favorite targets for a therapeutic goal to inhibit metastasis. However, data about the effect of the combination of TME cells on metastasis have a small part in the literature.

Adipogenesis in triple-negative breast cancer is associated with unfavorable tumor immune microenvironment and with worse survival

Cancer-associated adipocytes are known to cause inflammation; however, the role of adipogenesis, the formation of adipocytes, in breast cancer is unclear. We hypothesized that intra-tumoral adipogenesis reflects a different cancer biology than abundance of intra-tumoral adipocytes. The Molecular Signatures Database Hallmark adipogenesis gene set of gene set variant analysis was used to quantify adipogenesis. Total of 5,098 breast cancer patients in multiple cohorts (training; GSE96058 (n = 3273), validation; TCGA (n = 1069), treatment response; GSE25066 (n = 508) and GSE20194 (n = 248)) were analyzed. Adipogenesis did not correlate with abundance of adipocytes. Adipogenesis was significantly lower in triple negative breast cancer (TNBC). Elevated adipogenesis was significantly associated with worse survival in TNBC, but not in the other subtypes. High adipogenesis TNBC was significantly associated with low homologous recombination deficiency, but not with mutation load. High adipogenesis TNBC enriched metabolism-related gene sets, but neither of cell proliferation- nor inflammation-related gene sets, which were enriched to adipocytes. High adipogenesis TNBC was infiltrated with low CD8⁺ T cells and high M2 macrophages. Although adipogenesis was not associated with neoadjuvant chemotherapy response, high adipogenesis TNBC was significantly associated with low expression of PD-L1 and PD-L2 genes, and immune checkpoint molecules index. In conclusion, adipogenesis in TNBC was associated with cancer metabolism and unfavorable tumor immune microenvironment, which is different from abundance of adipocytes.

Design of New Improved Curcumin Derivatives to Multi-targets of Cancer and Inflammation

BACKGROUND

Curcumin is a major active principle of Curcuma longa. There are more than 1700 citations in the Medline, reflecting various biological effects of curcumin. Most of these biological activities are associated with the antioxidant, anti-inflammatory and antitumor activity of the molecule. Several reports suggest various targets of natural curcumin that include growth factors, growth factor receptor, cytokines, enzymes and gene regulators of apoptosis. This review focuses on the improved curcumin derivatives that target the cancer and inflammation.

METHODOLOGY

In this present review, we explored the anticancer drugs with curcumin-based drugs under pre-clinical and clinical studies with critical examination. Based on the strong scientific reports of patentable and non-patented literature survey, we have investigated the mode of the interactions of curcumin-based molecules with the target molecules.

RESULTS

Advanced studies have added new dimensions of the molecular response of cancer cells to curcumin at the genomic level. However, poor bioavailability of the molecule seems to be the major limitation of the curcumin. Several researchers have been involved to improve the curcumin derivatives to overcome this limitation. Sufficient data of clinical trials to various cancers that include multiple myeloma, pancreatic cancer and colon cancer, have also been discussed.

CONCLUSION

The detailed analysis of the structure-activity relationship (SAR) and common synthesis of curcumin-based derivatives have been discussed in the review. Utilising the predictions of in silico coupled with validation reports of in vitro and in vivo studies have concluded many targets for curcumin. Among them, cancer-related inflammation genes regulating curcumin-based molecules are a very promising target to overcome hurdles in the multimodality therapy of cancer.

Inflammation-Driven Breast Tumor Cell Plasticity: Stemness/EMT, Therapy Resistance and Dormancy

Cellular heterogeneity poses an immense therapeutic challenge in cancer due to a constant change in tumor cell characteristics, endowing cancer cells with the ability to dynamically shift between states. Intra-tumor heterogeneity is largely driven by cancer cell plasticity, demonstrated by the ability of malignant cells to acquire stemness and epithelial-to-mesenchymal transition (EMT) properties, to develop therapy resistance and to escape dormancy. These different aspects of cancer cell remodeling are driven by intrinsic as well as by extrinsic signals, the latter being dominated by factors of the tumor microenvironment. As part of the tumor milieu, chronic inflammation is generally regarded as a most influential player that supports tumor development and progression. In this review article, we put together recent findings on the roles of inflammatory elements in driving forward key processes of tumor cell plasticity. Using breast cancer as a representative research system, we demonstrate the critical roles played by inflammation-associated myeloid cells (mainly macrophages), pro-inflammatory cytokines [such as tumor necrosis factor α (TNFα) and interleukin 6 (IL-6)] and inflammatory chemokines [primarily CXCL8 (interleukin 8, IL-8) and CXCL1 (GROα)] in promoting tumor cell remodeling. These inflammatory components form a common thread that is involved in regulation of the three plasticity levels: stemness/EMT, therapy resistance, and dormancy. In view of the fact that inflammatory elements are a common denominator shared by different aspects of tumor cell plasticity, it is possible that their targeting may have a critical clinical benefit for cancer patients.

Intratumoral Adipocyte-High Breast Cancer Enrich for Metastatic and Inflammation-Related Pathways but Associated with Less Cancer Cell Proliferation

Cancer-associated adipocytes are known to cause inflammation, leading to cancer progression and metastasis. The clinicopathological and transcriptomic data from 2256 patients with breast cancer were obtained based on three cohorts: The Cancer Genome Atlas (TCGA), GSE25066, and a study by Yau et al. For the current study, we defined the adipocyte, which is calculated by utilizing a computational algorithm, xCell, as "intratumoral adipocyte". These intratumoral adipocytes appropriately reflected mature adipocytes in a bulk tumor. The amount of intratumoral adipocytes demonstrated no relationship with survival. Intratumoral adipocyte-high tumors significantly enriched for metastasis and inflammation-related gene sets and are associated with a favorable tumor immune microenvironment, especially in the ER+/HER2- subtype. On the other hand, intratumoral adipocyte-low tumors significantly enriched for cell cycle and cell proliferation-related gene sets. Correspondingly, intratumoral adipocyte-low tumors are associated with advanced pathological grades and inversely correlated with MKI67 expression. In conclusion, a high amount of intratumoral adipocytes in breast cancer was associated with inflammation, metastatic pathways, cancer stemness, and favorable tumor immune microenvironment. However, a low amount of adipocytes was associated with a highly proliferative tumor in ER-positive breast cancer. This cancer biology may explain the reason why patient survival did not differ by the amount of adipocytes.

Partners in crime: TNFα-based networks promoting cancer progression

Current therapeutic approaches in malignancy are often based on combination therapies, reflecting present understanding of the way different players act together in cancer. The cooperative activity of several elements can potentiate the pro-metastatic functions of the cancer cells and of the tumor microenvironment (TME), together leading to a more aggressive disease phenotype. The design of improved therapeutic modalities requires better identification of networks that act at specific cancer-related settings, and of the molecular mechanisms involved. Such studies will indicate if therapies that co-target several factors or their receptors, simultaneously, could apply. Also, by delineating the intracellular pathways that are activated under such cooperative activities, it will be possible to determine whether to inhibit one specific molecular route that is shared by the different partners, or alternatively, design modalities that jointly target intracellular components acting in concert. This Focused Research Review illuminates the therapeutic relevance of this research field by describing our published findings in breast cancer-related publications, which identified networks that are established by the pro-inflammatory/pro-metastatic cytokine TNFα. It describes the additive/synergistic activities of TNFα with other soluble factors residing at the TME (e.g., IL-1β, TGFβ1, estrogen, EGF), with intracellular components such as the Ras oncogene, and with the tumor-stroma contexture through the activation of molecular cascades (Notch). The roles of the p65 (NF-κB) pathway-acting alone or in intricate relationships with other intracellular mechanisms-are described, the "TNFα-based network" is discussed as a general paradigm in malignancy and its clinical implications in cancer therapy are addressed.

Importance of EMT Factor ZEB1 in cDC1 "MutuDC Line" Mediated Induction of Th1 Immune Response

The role of Epithelial to Mesenchymal Transition (EMT) factor Zeb1 is well defined in metastasis and cancer progression but it's importance in dendritic cells (DCs) is unexplored until now. For the first time we report here that Zeb1 controls immunogenic responses of CD8α⁺ conventional Type-I (cDC1) DCs. We found that ZEB1 expression increases significantly after TLR9 stimulation and its depletion impairs activation, co-stimulation and secretion of important cytokines like IL-6, IL-10 and IL-12 in cDC1 MutuDC line. We further confirmed our findings in primary cDC1 DCs derived from bone marrow. Co-culture of these Zeb1 knock down (KD) DCs with OT-II CD4⁺ T helper cells skewed their differentiation toward Th2 subtype. Moreover, adoptive transfer of activated Zeb1 KD DCs cleared intestinal worms in helminth infected mice by increasing Th2 responses in vivo. Integrative genomic analysis showed Zeb1 as an activator of immune response genes in cDC1 MutuDCs as compared to other pathway genes. In addition, differentially regulated genes in Zeb1 KD RNA-seq showed significant enrichment of Th2 activation pathways supporting our in vitro findings. Mechanistically, we showed that decreased IL-12 secreted by Zeb1 KD DCs is the plausible mechanism for increased Th2 differentiation. Collectively our data demonstrate that Zeb1 could be targeted in DCs to modulate T-cell mediated adaptive immune responses.

PAR1 signaling on tumor cells limits tumor growth by maintaining a mesenchymal phenotype in pancreatic cancer

Protease activated receptor-1 (PAR1) expression is associated with disease progression and overall survival in a variety of cancers. However, the importance of tumor cell PAR1 in pancreatic ductal adenocarcinomas (PDAC) remains unexplored. Utilizing orthotopic models with wild type and PAR1-targeted PDAC cells, we show that tumor cell PAR1 negatively affects PDAC growth, yet promotes metastasis. Mechanistically, we show that tumor cell-specific PAR1 expression correlates with mesenchymal signatures in PDAC and that PAR1 is linked to the maintenance of a partial mesenchymal cell state. Indeed, loss of PAR1 expression results in well-differentiated pancreatic tumors in vivo, with enhanced epithelial characteristics both in vitro and in vivo. Taken together, we have identified a novel growth inhibitory role of PAR1 in PDAC, which is linked to the induction, and maintenance of a mesenchymal-like phenotype. The recognition that PAR1 actively limits pancreatic cancer cell growth suggest that the contributions of PAR1 to tumor growth differ between cancers of epithelial origin and that its targeting should be applied with care.

MicroRNAs in regulation of triple-negative breast cancer progression

PURPOSE

Dysregulation of miRNA profile has been associated with a broad spectrum of cellular processes underlying progression of various human malignancies. Increasing evidence suggests that specific microRNA clusters might be of clinical utility, especially in triple-negative breast carcinoma (TNBC), devoid of both predictive markers and potential therapeutic targets. Here we provide a comprehensive review of the existing data on microRNAs in TNBC, their molecular targets, a putative role in invasive progression with a particular emphasis on the epithelial-to-mesenchymal transition (EMT) and acquisition of stem-cell properties (CSC), regarded both as prerequisites for metastasis, and significance for therapy.

METHODS

PubMed and Medline databases were systematically searched for the relevant literature. 121 articles have been selected and thoroughly analysed.

RESULTS

Several miRNAs associated with EMT/CSC and invasion were identified as significantly (1) upregulated: miR-10b, miR-21, miR-29, miR-9, miR-221/222, miR-373 or (2) downregulated: miR-145, miR-199a-5p, miR-200 family, miR-203, miR-205 in TNBC. Dysregulation of miR-10b, miR-21, miR-29, miR-145, miR-200 family, miR-203, miR-221/222 was reported of prognostic value in TNBC patients.

CONCLUSION

Available data suggest that specific microRNA clusters might play an important role in biology of TNBC, understanding of which should assist disease prognostication and therapy.

Role of extracellular matrix in breast cancer development: a brief update

Evidence is increasing on the crucial role of the extracellular matrix (ECM) in breast cancer progression, invasion and metastasis with almost all mortality cases owing to metastasis. The epithelial-mesenchymal transition is the first signal of metastasis involving different transcription factors such as Snail, TWIST, and ZEB1. ECM remodeling is a major event promoting cancer invasion and metastasis; where matrix metalloproteinases (MMPs) such as MMP-2, -9, -11, and -14 play vital roles degrading the matrix proteins for cancer spread. The β-D mannuronic acid (MMP inhibitor) has anti-metastatic properties through inhibition of MMP-2, and -9 and could be a potential therapeutic agent. Besides the MMPs, the enzymes such as LOXL2, LOXL4, procollagen lysyl hydroxylase-2, and heparanase also regulate breast cancer progression. The important ECM proteins like integrins (b1-, b5-, and b6- integrins), ECM1 protein, and Hic-5 protein are also actively involved in breast cancer development. The stromal cells such as tumor-associated macrophages (TAMs), cancer-associated fibroblasts (CAFs), and adipocytes also contribute in tumor development through different processes. The TAMs become proangiogenic through secretion of VEGF-A and building vessel network for nourishment and invasion of the tumor mass. The latest developments of ECM involvement in breast cancer progression has been discussed in this review and this study will help researchers in designing future work on breast cancer pathogenesis and developing therapy targeted to the ECM components.

Musashi-1 regulates AKT-derived IL-6 autocrinal/paracrinal malignancy and chemoresistance in glioblastoma

Glioblastoma multiform (GBM) is one of the most lethal human malignant brain tumors with high risks of recurrence and poor treatment outcomes. The RNA-binding protein Musashi-1 (MSI1) is a marker of neural stem/progenitor cells. Recent study showed that high expression level of MSI1 positively correlates with advanced grade of GBM, where MSI1 increases the growth of GBM. Herein, we explore the roles of MSI1 as well as the underlying mechanisms in the regulation of drug resistance and tumorigenesis of GBM cells. Our results demonstrated that overexpression of MSI1 effectively protected GBM cells from drug-induced apoptosis through down-regulating pro-apoptotic genes; whereas inhibition of AKT withdrew the MSI1-induced anti-apoptosis and cell survival. We further showed that MSI1 robustly promoted the secretion of the pro-inflammatory cytokine IL-6, which was governed by AKT activity. Autonomously, the secreted IL-6 enhanced AKT activity in an autocrine/paracrine manner, forming a positive feedback regulatory loop with the MSI1-AKT pathway. Our results conclusively demonstrated a novel drug resistance mechanism in GBM cells that MSI1 inhibits drug-induced apoptosis through AKT/IL6 regulatory circuit. MSI1 regulates both cellular signaling and tumor-microenvironmental cytokine secretion to create an intra- and intercellular niche for GBM to survive from chemo-drug attack.

Mesenchymal traits at the convergence of tumor-intrinsic and -extrinsic mechanisms of resistance to immune checkpoint blockers

Targeting of immune checkpoint blockers (ICBs), such as cytotoxic T-lymphocyte antigen-4 and programmed-death 1/programmed-death ligand 1, has dramatically changed the landscape of cancer treatment. Seeing patients who were refractory to conventional therapy recover after immunotherapy, with high rates of objective durable responses and increased overall survival, has raised great enthusiasm in cancer care and research. However, to date, only a restricted portion of patients benefit from these therapies, due to natural and acquired resistance relying on the ever-evolving cross-talk between tumor and stromal cells. Here, we review the convergence of tumor-intrinsic and -extrinsic cues, both affecting tumor plasticity and tumor stroma leading to an immunosuppressive tumor microenvironment, which may account for the heterogeneous responses and resistance to ICB therapies. A deeper knowledge of the mechanisms and fingerprints involved in natural and acquired resistance is likely to bring clinical benefit to the majority of patients, offering important clues for overcoming drug resistance and boosting the effectiveness of treatment. We discuss the need to define tumor subtypes based on the tumor, immune and stromal gene signature and propose that the better we understand tumor mesenchymal traits, the more we will be able to identify predictive biomarkers of response to ICB treatments.

α-Mangostin inhibits DMBA/TPA-induced skin cancer through inhibiting inflammation and promoting autophagy and apoptosis by regulating PI3K/Akt/mTOR signaling pathway in mice

Skin cancer is the most common form of cancer responsible for considerable morbidity and mortality, the treatment progress of which remains slow though. Therefore, studies identifying anti-skin cancer agents that are innocuous are urgently needed. α-Mangostin, a natural product isolated from the pericarp of mangosteen fruit, has potent anti-cancer activity. However, its role in skin cancer remains unclear. The aim of this study was to evaluate the treatment effect of α-mangostin on skin tumorigenesis induced by 9,10-dimethylbenz[a]anthracene (DMBA)/TPA in mice and the potential mechanism. Treatment with α-mangostin significantly suppressed tumor formation and growth, and markedly reduced the incidence rate. α-Mangostin not only inhibited the expressions of pro-inflammatory factors, but also promoted the production of anti-inflammatory factors in tumor and blood. It induced autophagy of skin tumor and regulated the expressions of autophagy-related proteins. The protein expressions of LC3, LC3-II and Beclin1 increased whereas those of LC3-I and p62 decreased after treatment with α-mangostin. Moreover, α-mangostin promoted the apoptosis of skin tumor dose-dependently by up-regulating of Bax, cleaved caspase-3, cleaved PARP and Bad, and down-regulating of Bcl-2 and Bcl-xl. Furthermore, showed α-mangostin inhibited the PI3K/AKT/mTOR (mammalian target of rapamycin) signaling pathway, as evidenced by decreased expressions of phospho-PI3K (p-PI3K), p-Akt and p-mTOR, but did not affect the expressions of t-PI3K, t-Akt or t-mTOR. Collectively, α-mangostin suppressed murine skin tumorigenesis induced by DMBA/TPA through inhibiting inflammation and promoting autophagy and apoptosis by regulating the PI3K/Akt/mTOR signaling pathway, as a potential candidate for future clinical therapy.

Deciphering the loop of epithelial-mesenchymal transition, inflammatory cytokines and cancer immunoediting

Tumorigenesis and tumor progression relies on the dialectics between tumor cells, the extracellular matrix and its remodelling enzymes, neighbouring cells and soluble cues. The host immune response is crucial in eliminating or promoting tumor growth and the reciprocal coevolution of tumor and immune cells, during disease progression and in response to therapy, shapes tumor fate by activating innate and adaptive mechanisms. The phenotypic plasticity is a common feature of epithelial and immune cells and epithelial-mesenchymal transition (EMT) is a dynamic process, governed by microenvironmental stimuli, critical in tumor cell shaping, increased tumor cell heterogeneity and stemness. In this review we will outline how the dysregulation of microenvironmental signaling is crucial in determining tumor plasticity and EMT, arguing how therapy resistance hinges on these dynamics.

LFG-500, a novel synthetic flavonoid, suppresses epithelial-mesenchymal transition in human lung adenocarcinoma cells by inhibiting NLRP3 in inflammatory microenvironment

Increasing evidence indicates that inflammatory microenvironment facilitates tumor metastasis. Here, we found that LFG-500, a novel synthetic flavonoid, significantly inhibited epithelial-mesenchymal transition (EMT) in human lung adenocarcinoma A549 and H1299 cells co-cultured with LPS-challenged THP-1 cells or cultured in THP-1 cell-derived conditioned medium. Moreover, we found that TNF-α is a direct and decisive factor for promoting EMT and LFG-500 suppressed TNF-α-induced EMT and cell motility. NLRP3 knockdown inactivated NLRP3 inflammasome, which subsequently inhibited EMT and blocked cell migration, indicating that TNF-α-induced EMT requires the NLRP3 inflammasome. LFG-500 inhibited the activation of the NLRP3 inflammasome, thus inhibiting EMT. Moreover, LFG-500 treatment significantly inhibited metastasis in vivo by downregulating NLRP3 expression. Importantly, we found that NLRP3 was highly expressed in high-grade lung adenocarcinoma and that its expression was correlated with lymph node metastasis. NLRP3 and vimentin levels were significantly increased in matched metastatic lymph nodes. Moreover, a significant positive correlation was observed between their levels. Together, these results suggest that LFG-500 markedly suppresses EMT by inhibiting the NLRP3 inflammasome in the inflammatory microenvironment and that NLRP3 is a potential biomarker of lung adenocarcinoma metastasis.

IL-1β, IL-8, and Matrix Metalloproteinases-1, -2, and -10 Are Enriched upon Monocyte-Breast Cancer Cell Cocultivation in a Matrigel-Based Three-Dimensional System

Breast cancer remains the first cancer-related cause of death in women worldwide, particularly in developing countries in which most cases are diagnosed in late stages. Although most cancer studies are based in the genetic or epigenetic changes of the tumor cells, immune cells within the tumor stroma often cooperate with cancer progression. Particularly, monocytes are attracted to the tumor primary site in which they are differentiated into tumor-associated macrophages that facilitate tumor cell invasion and metastasis. In this study, we used three-dimensional cultures to form acini-like structures to analyze the inflammatory secretion profile of tumor cells individually or in co-culture with monocytes. Breast cancer cell lines and primary isolates from eight Mexican patients with breast cancer were used. We found high levels of RANTES/CCL5, MCP-1/CCL2, and G-CSF in the breast cancer individual cultures, supporting an important recruitment capacity of monocytes, but also of neutrophils. The co-cultures of the tumor cells and monocytes were significantly enriched with the potent pro-inflammatory cytokines interleukin (IL)-1β and IL-8, known to support malignant progression. We also found that the interaction of tumor cells with monocytes promoted high levels of matrix metalloproteinases (MMP)-1, MMP-2, and MMP-10. Our study supports that a key event for malignant progression is the recruitment of different immune cell populations, which help to sustain and enhance a chronic inflammatory microenvironment that highly favors tumor malignancy.

Re-evaluating the role of epithelial-mesenchymal-transition in cancer progression

Epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are essential for embryonic development and also important in cancer progression. In a conventional model, epithelial-like cancer cells transit to mesenchymal-like tumor cells with great motility via EMT transcription factors; these mesenchymal-like cells migrate through the circulation system, relocate to a suitable site and then convert back to an epithelial-like phenotype to regenerate the tumor. However, recent findings challenge this conventional model and support the existence of a stable hybrid epithelial/mesenchymal (E/M) tumor population. Hybrid E/M tumor cells exhibit both epithelial and mesenchymal properties, possess great metastatic and tumorigenic capacity and are associated with poorer patient prognosis. The hybrid E/M model and associated regulatory networks represent a conceptual change regarding tumor metastasis and organ colonization. It may lead to the development of novel treatment strategies to ultimately stop cancer progression and improve disease-free survival.

HRD1 suppresses the growth and metastasis of breast cancer cells by promoting IGF-1R degradation

HRD1 (3-hydroxy-3-methylglutaryl reductase degradation) is an E3 ubiquitin ligase. We found that HRD1 was significantly downregulated in 170 breast cancer tissues. Low tumoral HRD1 expression was correlated with clinicopathological characteristics and a shorter survival in breast cancer patients. P65 specifically bound to the HRD1 promoter and inhibited HRD1 expression. Suppression of NF-κB activity reversed IL-6-induced downregulation of HRD1 expression. HRD1 interacted with IGF-1R and promoted its ubiquitination and degradation by the proteasome. Overexpression of HRD1 resulted in the inhibition of growth, migration and invasion of breast cancer cells in vitro and in vivo. Furthermore, HRD1 attenuated IL-6-induced epithelial-mesenchymal transition in MCF10A cells. These findings uncover a novel role for HRD1 in breast cancer.

Helicobacter pylori CagA and IL-1β Promote the Epithelial-to-Mesenchymal Transition in a Nontransformed Epithelial Cell Model

Gastric cancer is the third cause of cancer death worldwide and infection by Helicobacter pylori (H. pylori) is considered the most important risk factor, mainly by the activity of its virulence factor CagA. H. pylori/CagA-induced chronic inflammation triggers a series of gastric lesions of increased severity, starting with gastritis and ending with cancer. IL-1β has been associated with tumor development and invasiveness in different types of cancer, including gastric cancer. Currently, it is not clear if there is an association between CagA and IL-1β at a cellular level. In this study, we analyzed the effects of IL-1β and CagA on MCF-10A nontransformed cells. We found evidence that both CagA and IL-1β trigger the initiation of the epithelial-to-mesenchymal transition characterized by β-catenin nuclear translocation, increased expression of Snail1 and ZEB1, downregulation of CDH1, and morphological changes during MCF-10A acini formation. However, only CagA induced MMP9 activity and cell invasion. Our data support that IL-1β and CagA target the β-catenin pathway, with CagA leading to acquisition of a stage related to aggressive tumors.

Contact-dependent carcinoma aggregate dispersion by M2a macrophages via ICAM-1 and β2 integrin interactions

Tumor-associated macrophages (TAMs) can constitute up to 50% of the tumor mass and have strong implications in tumor progression and metastasis. Macrophages are plastic and can polarize to various subtypes that differ in terms of surface receptor expression as well as cytokine and chemokine production and effector function. Conventionally, macrophages are grouped into two major subtypes: the classically activated M1 macrophages and the alternatively activated M2 macrophages. M1 macrophages are pro-inflammatory, promote T helper (Th) 1 responses, and show tumoricidal activity, whereas M2 macrophages contribute to tissue repair and promote Th2 responses. Herein, we present a microfluidic system integrating tumor cell aggregates and subtypes of human monocyte-derived macrophages in a three-dimensional hydrogel scaffold, in close co-culture with an endothelial monolayer to create an in vitro tumor microenvironment. This platform was utilized to study the role of individual subtypes of macrophages (M0, M1, M2a, M2b and M2c) in human lung adenocarcinoma (A549) aggregate dispersion, as a representation of epithelial-mesenchymal transition (EMT). A significant difference was observed when M2a macrophages were in direct contact with or separated from A549 aggregates, suggesting a possible mechanism for proximity-induced, contact-dependent dissemination via ICAM-1 and integrin β2 interactions. Indeed, M2a macrophages tended to infiltrate and release cells from carcinoma cell aggregates. These findings may help in the development of immunotherapies based on enhancing the tumor-suppressive properties of TAMs.

The tumor microenvironment: An irreplaceable element of tumor budding and epithelial-mesenchymal transition-mediated cancer metastasis

Tumor budding occurs at the invasive front of cancer; the tumor cells involved have metastatic and stemness features, indicating a poor prognosis. Tumor budding is partly responsible for cancer metastasis, and its initiation is based on the epithelial-mesenchymal transition (EMT) process. The EMT process involves the conversion of epithelial cells into migratory and invasive cells, and is a profound event in tumorigenesis. The EMT, associated with the formation of cancer stem cells (CSCs) and resistance to therapy, results from a combination of gene mutation, epigenetic regulation, and microenvironmental control. Tumor budding can be taken to represent the EMT in vivo. The EMT process is under the influence of the tumor microenvironment as well as tumor cells themselves. Here, we demonstrate that the tumor microenvironment dominates EMT development and impacts cancer metastasis, as well as promotes CSC formation and mediates drug resistance. In this review, we mainly discuss components of the microenvironment, such as the extracellular matrix (ECM), inflammatory cytokines, metabolic products, and hypoxia, that are involved in and impact on the acquisition of tumor-cell motility and dissemination, the EMT, metastatic tumor-cell formation, tumor budding and CSCs, and cancer metastasis, including subsequent chemo-resistance. From our point of view, the tumor microenvironment now constitutes a promising target for cancer therapy.

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes.

Mycobacterium tuberculosis H37Rv infected THP-1 cells induce epithelial mesenchymal transition (EMT) in lung adenocarcinoma epithelial cell line (A549)

Chronic infections of Mycobacterium tuberculosis (MTB) cause oxidative stress, TLR activation and production of inflammatory cytokines and thus can create an environment reinforcing tumorigenesis, progression and metastasis. Epidemiological studies have established a relation between lung cancer and tuberculosis but cellular mechanism is still poorly understood. In present study, we have shown for the first time that MTB infection in human monocytic cell line (THP-1) enhances invasion and induces EMT characteristics in lung adenocarcinoma cell line (A549) during co-culture. After co-culture with MTB infected THP-1 cells A549 cells exhibited morphological and molecular signatures of EMT. During co-culture, expression of inflammatory cytokines like TNF-α, IL-1β and IL-6 was enhanced in the microenvironment of A549 cells in comparison to single culture of A549 cells. Using pharmacological inhibitors of JNK (SP-600125) and p38 MAPK (SB-203580), we demonstrated the involvement of JNK and p38 MAPK in MTB induced EMT induction in A549 cells. To the best of our knowledge this is the first report demonstrating the role of MTB infection in induction of metastasis associated EMT in lung cancer.

Chemokine-Derived Peptides: Novel Antimicrobial and Antineoplasic Agents

Chemokines are a burgeoning family of chemotactic cytokines displaying a broad array of functions such as regulation of homeostatic leukocyte traffic and development, as well as activating the innate immune system. Their role in controlling early and late inflammatory stages is now well recognized. An improper balance either in chemokine synthesis or chemokine receptor expression contributes to various pathological disorders making chemokines and their receptors a useful therapeutic target. Research in this area is progressing rapidly, and development of novel agents based on chemokine/chemokine receptors antagonist functions are emerging as attractive alternative drugs. Some of these novel agents include generation of chemokine-derived peptides (CDP) with potential agonist and antagonist effects on inflammation, cancer and against bacterial infections. CDP have been generated mainly from N- and C-terminus chemokine sequences with subsequent modifications such as truncations or elongations. In this review, we present a glimpse of the different pharmacological actions reported for CDP and our current understanding regarding the potential use of CDP alone or as part of the novel therapies proposed in the treatment of microbial infections and cancer.

Activation of platelet protease-activated receptor-1 induces epithelial-mesenchymal transition and chemotaxis of colon cancer cell line SW620

The aim of the present study was to examine the role of protease-activated receptor-1 (PAR1)-stimulated platelet activation in the epithelial-mesenchymal transition (EMT) and migration of colon cancer cells, and to identify the underlying mechanisms. TFLLR-NH₂, a PAR1 agonist, was used to activate platelets and the platelet supernatants were used to treat the SW620 colon cancer cell line. Expression of E-cadherin and vimentin on SW620 cells was detected by immunofluorescence and western blotting, and the level of the transforming growth factor β1 (TGF-β1) was measured using ELISA following the activation of platelets by TFLLR-NH₂. miR-200b expression was detected using quantitative PCR in SW620 cells. In order to investigate the chemotactic ability of the SW620 cells, the expression of CXC chemokine receptor type 4 (CXCR4) was measured by flow cytometry. Transwell migration assays were performed following exposure of the cells to the supernatant of PAR1-activated platelets. SW620 cells cultured in the supernatant of TFLLR-NH₂-activated platelets upregulated E-cadherin expression and downregulated the vimentin expression. In the in vitro platelet culture system, a TFLLR-NH₂ dose-dependent increase of secreted TGF-β1 was detected in the supernatant. The activation of PAR1 on the platelets led to the inhibition of miR-200b expression in the SW620 cells that were cultured in platelet-conditioned media. The number of SW620 cells that penetrated through the Transwell membrane increased with the dose of TFLLR-NH₂ used to treat the platelets. The percentage of CXCR4-positive SW620 cells was significantly higher when they were exposed to the supernatant of platelets cultured for 24 h with PAR1 agonist than when cultured in non-conditioned media (40.89±6.74 vs. 3.47±1.40%, P<0.01). Platelet activation with a PAR1 agonist triggered TGF-β secretion, which induced EMT of SW620 human colon cancer cells via the downregulation of miR-200b expression, and activated platelets had a chemotactic effect on colon cancer cells mediated by the upregulation of CXCR4 on the cell surface.

Synthesis of phenolic amides and evaluation of their antioxidant and anti-inflammatory activity in vitro and in vivo

15 phenolic amides (PAs) have been synthesized and examinedin vitrousing four tests: (1) prevention of Cu²⁺-induced human low-density lipoprotein oxidation, (2) scavenging of stable radicals, (3) anti-inflammatory activity, and (4) scavenging of superoxide radicals.

Crosstalk of Oncogenic Signaling Pathways during Epithelial-Mesenchymal Transition

Epithelial–mesenchymal transition (EMT) and cell transformation have been well-documented in multiple cancer cell models and are believed to be one of the earliest events in tumor progression. Genetic and epigenetic modifications shift cells toward either end of the EMT spectrum, and can be influenced by the microenvironment surrounding a tumor. EMT and mesenchymal–epithelial transition are critical to normal function and development and an intricate network of transcription factors and transcriptional regulators tightly regulates these processes. As evidenced in normal and transformed cell lines, many signaling pathways trigger EMT during development and differentiation. The signaling pathways include those triggered by different members of the transforming growth factor superfamily, epidermal growth factor, fibroblast growth factor, hepatocyte growth factor, hypoxia-inducible factor, Wnt, Notch, and many others. Functional redundancies allow cells to undergo EMT even if these key transcriptional regulators are lacking, but these same redundancies also make these pathways particularly susceptible to gain-of-function mutations or constitutive signal activation; the “forced” transition toward either a mesenchymal or epithelial phenotype.

Cancer subclonal genetic architecture as a key to personalized medicine

The future of personalized oncological therapy will likely rely on evidence-based medicine to integrate all of the available evidence to delineate the most efficacious treatment option for the patient. To undertake evidence-based medicine through use of targeted therapy regimens, identification of the specific underlying causative mutation(s) driving growth and progression of a patient's tumor is imperative. Although molecular subtyping is important for planning and treatment, intraclonal genetic diversity has been recently highlighted as having significant implications for biopsy-based prognosis. Overall, delineation of the clonal architecture of a patient's cancer and how this will impact on the selection of the most efficacious therapy remain a topic of intense interest.

Deconstructing breast cancer cell biology and the mechanisms of multidrug resistance

Cancer complexity constantly challenges the way that clinicians manage breast cancer therapy. Tumor heterogeneity and intratumoral stroma characteristics allow cells with different phenotypes and deregulated apoptotic, proliferative and migration abilities to co-exist contributing to a disappointing therapeutic response. While new approaches are being associated with conventional chemotherapy, such as hormonal therapy or target monoclonal antibodies, recurrence and metastasization are still observed. Membrane transporters are the cell's first line of contact with anticancer drugs having a major role in multidrug resistance events. This structural-based activity enables the cell to be drug-resistant by decreasing drug intracellular concentration through an efflux-transport mechanism, mainly associated with overexpression of ATP-binding cassette (ABC) proteins. This review focuses on some of the important structural and biological properties of the malignant cell and tumor microenvironment, addressing the role of the membrane ABC transporters in therapeutic outcomes, and highlighting related molecular pathways that may represent meaningful target therapies.