Macrophage inflammatory factors promote epithelial-mesenchymal transition in breast cancer

Inhibition of MMP-2 and MMP-9 by Dietary Antioxidants in THP-1 Macrophages and Sera from Patients with Breast Cancer

Polyphenols, the main antioxidants of diet, have shown anti-inflammatory, antioxidant and anticarcinogenic activities. Here, we compared the effects of four polyphenolic compounds on ROS production and on the levels of matrix metalloproteinase (MMP)-2 and -9, which represent important pathogenetic factors of breast cancer. THP-1 differentiated macrophages were activated by LPS and simultaneously treated with different doses of a green tea extract (GTE), resveratrol (RSV), curcumin (CRC) and an olive fruit extract (oliplus). By using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, we found that all of the tested compounds showed antioxidant activity in vitro. In addition, GTE, RSV and CRC were able to counteract ROS production induced by H2O2 in THP-1 cells. As assessed by a zymographic analysis of THP-1 supernatants and by an "in-gel zymography" of a pool of sera from patients with breast cancer, the antioxidant compounds used in this study inhibited both the activity and expression of MMP-2 and MMP-9 through different mechanisms related to their structures and to their ability to scavenge ROS. The results of this study suggest that the used antioxidants could be promising agents for the prevention and complementary treatment of breast cancer and other diseases in which MMPs play a pivotal role.

Dual-Sensitive Fluorescent Nanoprobes for Simultaneously Monitoring In Situ Changes in pH and Matrix Metalloproteinase Expression in Stiffness-Tunable Three-Dimensional In Vitro Scaffolds

A tumor microenvironment often presents altered physicochemical characteristics of the extracellular matrix (ECM) including changes in matrix composition, stiffness, protein expression, pH, temperature, or the presence of certain stromal and immune cells. Of these, overexpression of matrix metalloproteinases (MMPs) and extracellular acidosis are the two major hallmarks of cancer that can be exploited for tumor detection. The change in matrix stiffness and the release of certain cytokines (TNF-α) in the tumor microenvironment play major roles in inducing MMP-9 expression in cancerous cells. This study highlights the role of mechanical cues in upregulating MMP-9 expression in cancerous cells using stiffness-tunable matrix compositions and dual-sensitive fluorescent nanoprobes. Ionically cross-linked 3D alginate/gelatin (AG) scaffolds with three stiffnesses were chosen to reflect the ECM stiffnesses corresponding to healthy and pathological tissues. Moreover, a dual-sensitive nanoprobe, an MMP-sensitive peptide conjugated to carbon nanoparticles with intrinsic pH fluorescence properties, was utilized for in situ monitoring of the two cancer hallmarks in the 3D scaffolds. This platform was further utilized for designing a 3D core-shell platform for spatially mapping tumor margins and for visualizing TNF-α-induced MMP-9 expression in cancerous cells.

5-Oxo-ETE/OXER1: A Link between Tumor Cells and Macrophages Leading to Regulation of Migration

Chronic inflammation is an important factor in the development of cancer. Macrophages found in tumors, known as tumor associated macrophages (TAMs), are key players in this process, promoting tumor growth through humoral and cellular mechanisms. 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE), an arachidonic acid metabolite, has been described to possess a potent chemoattractant activity for human white blood cells (WBCs). The biological actions of 5-oxo-ETE are mediated through the GPCR 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid receptor (OXER1). In addition, we have previously reported OXER1 as one of the membrane androgen receptors with testosterone antagonizing 5-oxo-ETE's actions. OXER1 is highly expressed in inflammatory cells and many normal and cancer tissues and cells, including prostate and breast cancer, promoting cancer cell survival. In the present study we investigate the expression and role of OXER1 in WBCs, THP-1 monocytes, and THP-1 derived macrophages, as well as its possible role in the interaction between macrophages and cancer cells (DU-145 and T47D). We report that OXER1 is differentially expressed between WBCs and macrophages and that receptor expression is modified by LPS treatment. Our results show that testosterone and 5-oxo-ETE can act in an antagonistic way affecting Ca2+ movements, migration, and cytokines' expression in immune-related cells, in a differentiation-dependent manner. Finally, we report that 5-oxo-ETE, through OXER1, can attract macrophages to the tumor site while tumor cells' OXER1 activation in DU-145 prostate and T47D breast cancer cells, by macrophages, induces actin cytoskeletal changes and increases their migration.

The transcriptome signature analysis of the epithelial-mesenchymal transition and immune cell infiltration in colon adenocarcinoma

The epithelial-mesenchymal transition (EMT) process is tightly connected to tumors' immune microenvironment. In colon adenocarcinoma (COAD), both the EMT and immune cell infiltration contribute to tumor progression; however, several questions regarding the mechanisms governing the interaction between EMT and the immune response remain unanswered. Our study aims to investigate the cross-talk between these two processes in cases of COAD and identify the key regulators involved. We utilized the EMT and immune signatures of samples from the COAD-TCGA database to identify three subtypes of COAD: high mesenchymal, medium mesenchymal, and low mesenchymal. We observed that EMT was associated with increased tumor immune response and infiltration mediated by pro-inflammatory cytokines. However, EMT was also linked to immunosuppressive activity that involved regulatory T cells, dendritic cells, and the upregulated expression of multiple immune checkpoints, such as PD-1, PDL-1, CTLA-4, and others. Finally, we employed the multivariate random forest feature importance method to identify key genes, such as DOK2 and MSRB3, that may play crucial roles in both EMT and the intratumoral immune response.

Connexin-43 hemichannels orchestrate NOD-like receptor protein-3 (NLRP3) inflammasome activation and sterile inflammation in tubular injury

BACKGROUND

Without a viable cure, chronic kidney disease is a global health concern. Inflammatory damage in and around the renal tubules dictates disease severity and is contributed to by multiple cell types. Activated in response to danger associated molecular patterns (DAMPs) including ATP, the NOD-like receptor protein-3 (NLRP3) inflammasome is integral to this inflammation. In vivo, we have previously observed that increased expression of Connexin 43 (Cx43) is linked to inflammation in chronic kidney disease (CKD) whilst in vitro studies in human proximal tubule cells highlight a role for aberrant Cx43 hemichannel mediated ATP release in tubule injury. A role for Cx43 hemichannels in priming and activation of the NLRP3 inflammasome in tubule epithelial cells remains to be determined.

METHODS

Using the Nephroseq database, analysis of unpublished transcriptomic data, examined gene expression and correlation in human CKD. The unilateral ureteral obstruction (UUO) mouse model was combined with genetic (tubule-specific Cx43 knockout) and specific pharmacological blockade of Cx43 (Peptide5), to explore a role for Cx43-hemichannels in tubule damage. Human primary tubule epithelial cells were used as an in vitro model of CKD.

RESULTS

Increased Cx43 and NLRP3 expression correlates with declining glomerular filtration rate and increased proteinuria in biopsies isolated from patients with CKD. Connexin 43-tubule deletion prior to UUO protected against tubular injury, increased expression of proinflammatory molecules, and significantly reduced NLRP3 expression and downstream signalling mediators. Accompanied by a reduction in F4/80 macrophages and fibroblast specific protein (FSP1+) fibroblasts, Cx43 specific hemichannel blocker Peptide5 conferred similar protection in UUO mice. In vitro, Peptide5 determined that increased Cx43-hemichannel activity primes and activates the NLRP3 inflammasome via ATP-P2X7 receptor signalling culminating in increased secretion of chemokines and cytokines, each of which are elevated in individuals with CKD. Inhibition of NLRP3 and caspase 1 similarly decreased markers of tubular injury, whilst preventing the perpetual increase in Cx43-hemichannel activity.

CONCLUSION

Aberrant Cx43-hemichannel activity in kidney tubule cells contributes to tubule inflammation via activation of the NLRP3 inflammasome and downstream paracrine mediated cell signalling. Use of hemichannel blockers in targeting Cx43-hemichannels is an attractive future therapeutic target to slow or prevent disease progression in CKD. Video Abstract.

CXCL8 Promotes Endothelial-to-Mesenchymal Transition of Endothelial Cells and Protects Cells from Erastin-Induced Ferroptosis via CXCR2-Mediated Activation of the NF-κB Signaling Pathway

CXCL8-CXCR1/CXCR2 signaling pathways might form complex crosstalk among different cell types within the ovarian tumor microenvironment, thereby modulating the behaviors of different cells. This study aimed to investigate the expression pattern of CXCL8 in the ovarian tumor microenvironment and its impact on both endothelial-to-mesenchymal transition (EndMT) and ferroptosis of endothelial cells. The human monocytic cell line THP-1 and the human umbilical vein endothelial cell line PUMC-HUVEC-T1 were used to conduct in vitro studies. Erastin was used to induce ferroptosis. Results showed that tumor-associated macrophages are the major source of CXCL8 in the tumor microenvironment. CXCL8 treatment promoted the nucleus entrance of NF-κB p65 and p65 phosphorylation via CXCR2 in endothelial cells, suggesting activated NF-κB signaling. Via the NF-κB signaling pathway, CXCL8 enhanced TGF-β1-induced EndMT of PUMC-HUVEC-T1 cells and elevated their expression of SLC7A11 and GPX4. These trends were drastically weakened in groups with CXCR2 knockdown or SB225002 treatment. TPCA-1 reversed CXCL8-induced upregulation of SLC7A11 and GPX4. CXCL8 protected endothelial cells from erastin-induced ferroptosis. However, these protective effects were largely canceled when CXCR2 was knocked down. In summary, CXCL8 can activate the NF-κB signaling pathway in endothelial cells in a CXCR2-dependent manner. The CXCL8-CXCR2/NF-κB axis can enhance EndMT and activate SLC7A11 and GPX4 expression, protecting endothelial cells from ferroptosis.

Sirtuin-dependent metabolic and epigenetic regulation of macrophages during tuberculosis

Macrophages are the preeminent phagocytic cells which control multiple infections. Tuberculosis a leading cause of death in mankind and the causative organism Mycobacterium tuberculosis (MTB) infects and persists in macrophages. Macrophages use reactive oxygen and nitrogen species (ROS/RNS) and autophagy to kill and degrade microbes including MTB. Glucose metabolism regulates the macrophage-mediated antimicrobial mechanisms. Whereas glucose is essential for the growth of cells in immune cells, glucose metabolism and its downsteam metabolic pathways generate key mediators which are essential co-substrates for post-translational modifications of histone proteins, which in turn, epigenetically regulate gene expression. Herein, we describe the role of sirtuins which are NAD+-dependent histone histone/protein deacetylases during the epigenetic regulation of autophagy, the production of ROS/RNS, acetyl-CoA, NAD+, and S-adenosine methionine (SAM), and illustrate the cross-talk between immunometabolism and epigenetics on macrophage activation. We highlight sirtuins as emerging therapeutic targets for modifying immunometabolism to alter macrophage phenotype and antimicrobial function.

Tissue-resident macrophages are major tumor-associated macrophage resources, contributing to early TNBC development, recurrence, and metastases

Triple-negative breast cancer (TNBC) is an aggressive and highly heterogenous disease with no well-defined therapeutic targets. Treatment options are thus limited and mortality is significantly higher compared with other breast cancer subtypes. Mammary gland tissue-resident macrophages (MGTRMs) are found to be the most abundant stromal cells in early TNBC before angiogenesis. We therefore aimed to explore novel therapeutic approaches for TNBC by focusing on MGTRMs. Local depletion of MGTRMs in mammary gland fat pads the day before TNBC cell transplantation significantly reduced tumor growth and tumor-associated macrophage (TAM) infiltration in mice. Furthermore, local depletion of MGTRMs at the site of TNBC resection markedly reduced recurrence and distant metastases, and improved chemotherapy outcomes. This study demonstrates that MGTRMs are a major TAM resource and play pivotal roles in the growth and malignant progression of TNBC. The results highlight a possible novel anti-cancer approach targeting tissue-resident macrophages.

Invasion characteristics and clinical significance of tumor-associated macrophages in gastrointestinal Krukenberg tumors

Background

Tumor-associated macrophages (TAMs) have been used as potential drug targets in preclinical research and clinical trials of various cancers. However, their distribution in Krukenberg tumors (KTs) remains unclear. We investigated the expression and prognostic value of TAMs in patients with gastrointestinal cancer with KTs.

Methods

The infiltration of various types of TAMs was detected in surgical tissues of 35 patients with KTs using immunohistochemical staining. The level of infiltration of TAMs in tumor nests (TN), tumor stroma (TS), and invasive margin (IM) areas was evaluated. The Kaplan-Meier method and univariate/multivariate Cox regression risk models were used to analyze the relationship between the degree of TAMs invasion and overall survival (OS) and progression-free survival (PFS).

Results

The distribution of TAMs exhibited spatial heterogeneity between TN, TS, and IM regions in primary tumor (PT) and KT tissues. TAMs infiltrated in the TN had greater prognostic value and were barely influenced by preoperative neoadjuvant therapy, despite similar grades of invasion in PT and KT tissues. Moreover, the number of CD68+ TAMs in TN of KT tissues was an independent risk factor affecting patient OS, whereas tumor resection scope might be an independent risk factor affecting patient PFS.

Conclusions

In view of the close relationship between TAMs, the tumor microenvironment and patient prognosis, targeting TAMs combined with chemotherapy is expected to become a new approach for the treatment of patients with KTs.

Breast cancers co-opt normal mechanisms of tolerance to promote immune evasion and metastasis

Normal developmental processes, such as those seen during embryonic development and postpartum mammary gland involution, can be reactivated by cancer cells to promote immune suppression, tumor growth, and metastatic spread. In mammalian embryos, paternal-derived antigens are at risk of being recognized as foreign by the maternal immune system. Suppression of the maternal immune response toward the fetus, which is mediated in part by the trophoblast, is critical to ensure embryonic survival and development. The postpartum mammary microenvironment also exhibits immunosuppressive mechanisms accompanying the massive cell death and tissue remodeling that occurs during mammary gland involution. These normal immunosuppressive mechanisms are paralleled during malignant transformation, where tumors can develop neoantigens that may be recognized as foreign by the immune system. To circumvent this, tumors can dedifferentiate and co-opt immune-suppressive mechanisms normally utilized during fetal tolerance and postpartum mammary involution. In this review, we discuss those similarities and how they can inform our understanding of cancer progression and metastasis.

Identification of Immune and Hypoxia Risk Classifier to Estimate Immune Microenvironment and Prognosis in Cervical Cancer

Purpose

Cervical cancer (CC) is one of the most common gynecologic neoplasms. Hypoxia is an essential trigger for activating immunosuppressive activity and initiating malignant tumors. However, the determination of the role of immunity and hypoxia on the clinical outcome of CC patients remains unclear.

Methods

The CC independent cohort were collected from TCGA database. Consensus cluster analysis was employed to determine a molecular subtype based on immune and hypoxia gene sets. Cox relevant analyses were utilized to set up a risk classifier for prognosis assessment. The underlying pathways of classifier genes were detected by GSEA. Moreover, we conducted CIBERSORT algorithm to mirror the immune status of CC samples.

Results

We observed two cluster related to immune and hypoxia status and found the significant difference in outcome of patients between the two clusters. A total of 251 candidate genes were extracted from the two clusters and enrolled into Cox relevant analyses. Then, seven hub genes (CCL20, CXCL2, ITGA5, PLOD2, PTGS2, TGFBI, and VEGFA) were selected to create an immune and hypoxia-based risk classifier (IHBRC). The IHBRC can precisely distinguish patient risk and estimate clinical outcomes. In addition, IHBRC was closely bound up with tumor associated pathways such as hypoxia, P53 signaling and TGF β signaling. IHBRC was also tightly associated with numerous types of immunocytes.

Conclusion

This academic research revealed that IHBRC can be served as predictor for prognosis assessment and cancer treatment estimation in CC.

P4HA2: A link between tumor-intrinsic hypoxia, partial EMT and collective migration

Epithelial-to-mesenchymal transition (EMT), a well-established phenomenon studied across pan-cancer types, has long been known to be a major player in driving tumor invasion and metastasis. Recent studies have highlighted the importance of partial EMT phenotypes in metastasis. Initially thought as a transitional state between epithelial and mesenchymal phenotypic states, partial EMT state is now widely recognized as a key driver of intra-tumoral heterogeneity and phenotypic plasticity, further accelerating tumor metastasis and therapeutic resistance. However, how tumor microenvironment regulates partial EMT phenotypes remains unclear. We have developed unique size-controlled three-dimensional microtumor models that recapitulate tumor-intrinsic hypoxia and the emergence of collectively migrating cells. In this study, we further interrogate these microtumor models to understand how tumor-intrinsic hypoxia regulates partial EMT and collective migration in hypoxic large microtumors fabricated from T47D breast cancer cells. We compared global gene expression profiles of hypoxic, migratory microtumors to that of non-hypoxic, non-migratory microtumors at early and late time-points. Using our microtumor models, we identified unique gene signatures for tumor-intrinsic hypoxia (early versus late), partial EMT and migration (pre-migratory versus migratory phenotype). Through differential gene expression analysis between the microtumor models with an overlap of hypoxia, partial EMT and migration signatures, we identified prolyl 4-hydroxylase subunit 2 (P4HA2), a hypoxia responsive gene, as a central regulator common to hypoxia, partial EMT and collective migration. Further, the inhibition of P4HA2 significantly blocked collective migration in hypoxic microtumors. Thus, using the integrated computational-experimental analysis, we identify the key role of P4HA2 in tumor-intrinsic hypoxia-driven partial EMT and collective migration.

Plasticity towards Rigidity: A Macrophage Conundrum in Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic, and ultimately fatal diffuse parenchymal lung disease. The molecular mechanisms of fibrosis in IPF patients are not fully understood and there is a lack of effective treatments. For decades, different types of drugs such as immunosuppressants and antioxidants have been tested, usually with unsuccessful results. Although two antifibrotic drugs (Nintedanib and Pirfenidone) are approved and used for the treatment of IPF, side effects are common, and they only slow down disease progression without improving patients’ survival. Macrophages are central to lung homeostasis, wound healing, and injury. Depending on the stimulus in the microenvironment, macrophages may contribute to fibrosis, but also, they may play a role in the amelioration of fibrosis. In this review, we explore the role of macrophages in IPF in relation to the fibrotic processes, epithelial–mesenchymal transition (EMT), and their crosstalk with resident and recruited cells and we emphasized the importance of macrophages in finding new treatments.

Macrophage induced ERK-TGF-β1 signaling in MCF7 breast cancer cells result in reversible cancer stem cell plasticity and epithelial mesenchymal transition

BACKGROUND

Breast cancer is a heterogenous disease composed of multiple clonal populations and the mechanism by which the tumor microenvironment induces cancer stem cell plasticity is not fully understood.

METHODS

MCF7 breast cancer cells were treated with macrophage conditioned medium (MɸCM). PD98059 and SB431542 were used for ERK and TGF-βR inhibition respectively. Epithelial-mesenchymal transition (EMT) and cancer stem cell markers (CSC) were studied using qRT-PCR and flowcytometry. SCID mice were used for animal experiments.

RESULTS

MɸCM- induced ERK/TGF-β1 signaling led to enrichment of CSC and EMT in MCF7 cells and mammospheres. These effects were abrogated by both MEK inhibitor PD98059 (TGF-β1 synthesis) and SB431542 (TGF-β1 signaling). The increase in CSC was both hybrid (ALDH1⁺) and mesenchymal (CD44⁺ CD24^- cells). Increase in hybrid E/M state was at a single cell level as confirmed by the increase in both claudin-1 (E) and vimentin (M). This did not have any growth advantage in SCID mice and monitoring of CSC and EMT markers before and after growth in SCID mice indicated reversal of these markers in tumor cells recovered from mice. Removal of MɸCM and neutralization of TNF-α, IL-6 and IL-1β in MɸCM abrogated ERK phosphorylation, TGF-β and CSC enrichment indicating the requirement of continuous signaling for maintenance.

CONCLUSIONS

ERK signaling plays an important role in MɸCM- induced EMT and CSC plasticity which is completely reversible upon withdrawal of signals.

GENERAL SIGNIFICANCE

Our experimental observations support the semi-independent nature of EMT-stemness connection which is very dynamic and reversible depending on the microenvironment.

Inflammatory Breast Cancer: The Secretome of HCMV+ Tumor-Associated Macrophages Enhances Proliferation, Invasion, Colony Formation, and Expression of Cancer Stem Cell Markers

Inflammatory breast cancer (IBC) is a highly aggressive phenotype of breast cancer that is characterized by a high incidence early metastasis. We previously reported a significant association of human cytomegalovirus (HCMV) DNA in the carcinoma tissues of IBC patients but not in the adjacent normal tissues. HCMV-infected macrophages serve as “mobile vectors” for spreading and disseminating virus to different organs, and IBC cancer tissues are highly infiltrated by tumor-associated macrophages (TAMs) that enhance IBC progression and promote breast cancer stem cell (BCSC)-like properties. Therefore, there is a need to understand the role of HCMV-infected TAMs in IBC progression. The present study aimed to test the effect of the secretome (cytokines and secreted factors) of TAMs derived from HCMV⁺ monocytes isolated from IBC specimens on the proliferation, invasion, and BCSC abundance when tested on the IBC cell line SUM149. HCMV⁺ monocytes were isolated from IBC patients during modified radical mastectomy surgery and tested in vitro for polarization into TAMs using the secretome of SUM149 cells. MTT, clonogenic, invasion, real-time PCR arrays, PathScan Intracellular Signaling array, and cytokine arrays were used to characterize the secretome of HCMV⁺ TAMs for their effect on the progression of SUM149 cells. The results showed that the secretome of HCMV⁺ TAMs expressed high levels of IL-6, IL-8, and MCP-1 cytokines compared to HCMV^- TAMs. In addition, the secretome of HCMV⁺ TAMs induced the proliferation, invasion, colony formation, and expression of BCSC-related genes in SUM149 cells compared to mock untreated cells. In addition, the secretome of HCMV⁺ TAMs activated the phosphorylation of intracellular signaling molecules p-STAT3, p-AMPKα, p-PRAS40, and p-SAPK/JNK in SUM149 cells. In conclusion, this study shows that the secretome of HCMV⁺ TAMs enhances the proliferation, invasion, colony formation, and BCSC properties by activating the phosphorylation of p-STAT3, p-AMPKα, p-PRAS40, and p-SAPK/JNK intracellular signaling molecules in IBC cells.

The role of senescence in cellular plasticity: Lessons from regeneration and development and implications for age-related diseases

Senescence is a cellular state which involves cell cycle arrest and a proinflammatory phenotype, and it has traditionally been associated with cellular and organismal aging. However, increasing evidence suggests key roles in tissue growth and regrowth, especially during development and regeneration. Conversely, cellular plasticity-the capacity of cells to undergo identity change, including differentiation and dedifferentiation-is associated with development and regeneration but is now being investigated in the context of age-related diseases such as Alzheimer disease. Here, we discuss the paradox of the role for cellular senescence in cellular plasticity: senescence can act as a cell-autonomous barrier and a paracrine driver of plasticity. We provide a conceptual framework for integrating recent data and use the interplay between cellular senescence and plasticity to provide insight into age-related diseases. Finally, we argue that age-related diseases can be better deciphered when senescence is recognized as a core mechanism of regeneration and development.

The Complex Biology of the Obesity-Induced, Metastasis-Promoting Tumor Microenvironment in Breast Cancer

Breast cancer is one of the most prevalent cancers in women contributing to cancer-related death in the advanced world. Apart from the menopausal status, the trigger for developing breast cancer may vary widely from race to lifestyle factors. Epidemiological studies refer to obesity-associated metabolic changes as a critical risk factor behind the progression of breast cancer. The plethora of signals arising due to obesity-induced changes in adipocytes present in breast tumor microenvironment, significantly affect the behavior of adjacent breast cells. Adipocytes from white adipose tissue are currently recognized as an active endocrine organ secreting different bioactive compounds. However, due to excess energy intake and increased fat accumulation, there are morphological followed by secretory changes in adipocytes, which make the breast microenvironment proinflammatory. This proinflammatory milieu not only increases the risk of breast cancer development through hormone conversion, but it also plays a role in breast cancer progression through the activation of effector proteins responsible for the biological phenomenon of metastasis. The aim of this review is to present a comprehensive picture of the complex biology of obesity-induced changes in white adipocytes and demonstrate the relationship between obesity and breast cancer progression to metastasis.

M1-like tumor-associated macrophages cascade a mesenchymal/stem-like phenotype of oral squamous cell carcinoma via the IL6/Stat3/THBS1 feedback loop

BACKGROUND

Tumor-associated macrophages (TAMs) have a leading position in the tumor microenvironment. Previously, we have demonstrated that M1-like TAMs activated by exosome-transferred THBS1 promote malignant migration in oral squamous cell carcinoma (OSCC). However, the functional roles and associated molecular mechanisms of the activated M1-like TAMs need to be further clarified in OSCC.

METHODS

Conditioned Media (CM) were harvested from the exosome activated M1-like TAMs. We measured the malignant behaviors of OSCC under the treatment of CM from M1-like TAMs by performing colony forming assays, invasion assays, wound-healing assays, spheroid forming assays and in vivo xenograft experiments. The underlying mechanisms were investigated by RNA-seq, cytokines analysis, intracellular signaling pathway analysis, ChIP assays, bioinformatics analysis and validation.

RESULTS

M1-like TAMs significantly promoted the epithelial-mesenchymal transition (EMT) process, and induced the cancer-stem like cells (CSCs) by upregulating the expression of MME and MMP14 in OSCC cells. Cytokine analysis revealed a shark increase of IL6 secretion from M1-like TAMs. Blocking IL6 in the CM from M1-like TAMs could significantly weaken its effects on the colony forming, invasion, migration, microsphere forming and xenograft forming abilities of OSCC cells. Cellular signaling assays indicated the activation of Jak/Stat3 pathway in the OSCC cells treated by the CM from M1-like TAMs. Blocking the activation of the Jak/Stat3 pathway could significantly weaken the effects of M1-like TAMs on the colony forming, invasion, migration, microsphere forming and xenograft forming abilities of OSCC cells. Further RNA-seq analysis and bioinformatics analysis revealed an increased expression of THBS1 in the OSCC cells treated by M1-like TAMs. Bioinformatics prediction and ChIP assays revealed the activation of Stat3 by CM from M1-like TAMs could directly promote the transcription of THBS1 in OSCC cells.

CONCLUSIONS

We proposed that M1-like TAMs could cascade a mesenchymal/stem-like phenotype of OSCC via the IL6/Stat3/THBS1 feedback loop. A better understanding on the functional roles and associated molecular mechanisms of M1-like TAMs might facilitate the development of novel therapies for supplementing the current treatment strategies for OSCC patients.

Exploration of genes and tumor infiltrating lymphocytes in female lung adenocarcinoma microenvironment that predicted prognosis

The tumor microenvironment has an important impact on tumor growth, invasion, metastasis, anti-tumor immune tolerance, and prognosis. The present study aimed to explore female lung adenocarcinoma microenvironment-associated tumor infiltrating lymphocytes (TILs) and genes that predict prognosis in The Cancer Genome Atlas (TCGA) database. Gene expression profiles of female patients with lung adenocarcinoma were downloaded from TCGA. Base on the CIBERSORT algorithm, we determined the fractions of TILs. By applying the ESTIMATE algorithm, immune scores and stromal scores were derived. According to the immune and stromal scores, we categorized the female patients with lung adenocarcinoma into high and low score groups. We also identified the fractions of TILs and differentially expressed genes (DEGs) that were significantly related with prognosis. The proportion of M1 macrophages was significantly negatively related to overall survival in female patients with lung adenocarcinoma. There were 269 upregulated genes and 35 downregulated genes both in immune scores and stromal scores. PTPRC (protein tyrosine phosphatase receptor type C) and GIMAP6 (GTPase, IMAP family member 6) were not only hub genes, but also were significantly related to overall survival in the Kaplan-Meier Plotter online and TCGA databases. In summary, our study provided new insight into the tumor microenvironment-related cellular and molecular mechanisms of women with lung adenocarcinoma. The results will be useful for future clinical studies.

Interplay between tumor microenvironment and partial EMT as the driver of tumor progression

Epithelial-to-mesenchymal transition (EMT), an evolutionary conserved phenomenon, has been extensively studied to address the unresolved variable treatment response across therapeutic regimes in cancer subtypes. EMT has long been envisaged to regulate tumor invasion, migration, and therapeutic resistance during tumorigenesis. However, recently it has been highlighted that EMT involves an intermediate partial EMT (pEMT) phenotype, defined by incomplete loss of epithelial markers and incomplete gain of mesenchymal markers. It has been further emphasized that pEMT transition involves a spectrum of intermediate hybrid states on either side of pEMT spectrum. Emerging evidence underlines bi-directional crosstalk between tumor cells and surrounding microenvironment in acquisition of pEMT phenotype. Although much work is still ongoing to gain mechanistic insights into regulation of pEMT phenotype, it is evident that pEMT plays a critical role in tumor aggressiveness, invasion, migration, and metastasis along with therapeutic resistance. In this review, we focus on important role of tumor-intrinsic factors and tumor microenvironment in driving pEMT and emphasize that engineered controlled microenvironments are instrumental to provide mechanistic insights into pEMT biology. We also discuss the significance of pEMT in regulating hallmarks of tumor progression i.e. cell cycle regulation, collective migration, and therapeutic resistance. Although constantly evolving, current progress and momentum in the pEMT field holds promise to unravel new therapeutic targets to halt tumor progression at early stages as well as tackle the complex therapeutic resistance observed across many cancer types.

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Partial EMT phenotype drives key hallmarks of tumor progression

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Role of tumor microenvironment in pEMT phenotype via cellular signaling pathways

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Engineering 3D in vitro models to study pEMT phenotype

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Opportunities and challenges in understanding pEMT phenotype

Ectopic expression of 35 kDa and knocking down of 78 kDa SG2NAs induce cytoskeletal reorganization, alter membrane sialylation, and modulate the markers of EMT

SG2NA is a protein of the striatin family that organizes STRIPAK complexes. It has splice variants expressing differentially in tissues. Its 78 kDa isoform regulates cell cycle, maintains homeostasis in the endoplasmic reticulum, and prevents oxidative injuries. The 35 kDa variant is devoid of the signature WD-40 repeats in the carboxy terminal, and its function is unknown. We expressed it in NIH 3T3 cells that otherwise express 78 kDa variant only. These cells (35 EE) have altered morphology, faster rate of migration, and enhanced growth as measured by the MTT assay. Similar phenotypes were also seen in cells where the endogenous 78 kDa isoform was downregulated by siRNA (78 KD). Proteomic analyses showed that several cancer-associated proteins are modulated in both 35 EE and 78 KD cells. The 35 EE cells have diffused actin fibers, distinctive ultrastructure, reduced sialylation, and increased expression of MMP2 & 9. The 78 KD cells also had diffused actin fibers and an upregulated expression of MMP2. In both cells, markers epithelial to mesenchymal transition (EMT) viz, E- & N-cadherins, β-catenin, slug, vimentin, and ZO-1 were modulated partially in tune with the EMT process. Since NIH 3T3 cells are mesenchymal, we also expressed 35 kDa SG2NA in MCF-7 cells of epithelial origin. In these cells (MCF-7-35), the actin fibers were also diffused and the modulation of the markers was more in tune with the EMT process. However, unlike in 35 EE cells, in MCF-7-35 cells, membrane sialylation rather increased. We infer that ectopic expression of 35 kDa and downregulation of 78 kDa SG2NAs partially induce transformed phenotypes.

Modeling of the immune response in the pathogenesis of solid tumors and its prognostic significance

BACKGROUND

Tumor initiation and subsequent progression are usually long-term processes, spread over time and conditioned by diverse aspects. Many cancers develop on the basis of chronic inflammation; however, despite dozens of years of research, little is known about the factors triggering neoplastic transformation under these conditions. Molecular characterization of both pathogenetic states, i.e., similarities and differences between chronic inflammation and cancer, is also poorly defined. The secretory activity of tumor cells may change the immunophenotype of immune cells and modify the extracellular microenvironment, which allows the bypass of host defense mechanisms and seems to have diagnostic and prognostic value. The phenomenon of immunosuppression is also present during chronic inflammation, and the development of cancer, due to its duration, predisposes patients to the promotion of chronic inflammation. The aim of our work was to discuss the above issues based on the latest scientific insights. A theoretical mechanism of cancer immunosuppression is also proposed.

CONCLUSIONS

Development of solid tumors may occur both during acute and chronic phases of inflammation. Differences in the regulation of immune responses between precancerous states and the cancers resulting from them emphasize the importance of immunosuppressive factors in oncogenesis. Cancer cells may, through their secretory activity and extracellular transport mechanisms, enhance deterioration of the immune system which, in turn, may have prognostic implications.

The Effect of a Fast-Releasing Hydrogen Sulfide Donor on Vascularization of Subcutaneous Scaffolds in Immunocompetent and Immunocompromised Mice

Islet transplantation into subcutaneous polymer scaffolds has shown to successfully induce normoglycemia in type 1 diabetes models. Vascularization of these scaffolds is imperative for optimal control of glucose levels. We studied the effect of the vascular stimulator hydrogen sulfide (H₂S) on the degree of vascularization of a scaffold and the role of the immune system in this process. Scaffolds were subcutaneously implanted in immunocompetent C57BL/6 and immunocompromised nude mice. Mice received twice-daily intraperitoneal injections of the fast-releasing H₂S donor sodium hydrosulfide (NaHS, 25 or 50 μmol/kg) or saline for 28 days. After 63 days the vascular network was analyzed by histology and gene expression. Here we showed that the vascularization of a subcutaneous scaffold in nude mice was significantly impaired by H₂S treatment. Both the CD31 gene and protein expression were reduced in these scaffolds compared to the saline-treated controls. In C57BL/6 mice, the opposite was found, the vascularization of the scaffold was significantly increased by H₂S. The mRNA expression of the angiogenesis marker CD105 was significantly increased compared to the controls as well as the number of CD31 positive blood vessels. In conclusion, the immune system plays an important role in the H₂S mediated effect on vascularization of subcutaneous scaffolds.

The interplay between cancer associated fibroblasts and immune cells in the context of radiation therapy

Fibroblasts are a key component of the tumor microenvironment (TME) that can serve as a scaffold for tumor cell migration and augment the tumor's ability to withstand harsh conditions. When activated by external or endogenous stimuli, normal fibroblasts become cancer associated fibroblasts (CAFs), a heterogeneous group of stromal cells in the tumor that are phenotypically and epigenetically different from normal fibroblasts. Dynamic crosstalk between cancer cells, immune cells, and CAFs through chemokines and surface signaling makes the TME conducive to tumor growth. When activated, CAFs promote tumorigenesis and metastasis through several phenomena including regulation of tumor immunity, metabolic reprogramming of the TME, extracellular matrix remodeling and contraction, and induction of therapeutic resistance. Ionizing radiation (radiation theraphy [RT]) is a potent immunological stimulant that has been shown to increase cytotoxic Teff infiltration and IFN-I stimulated genes. RT, however, is unable to overcome the infiltration and activation of immunosuppressive cells which can contribute to tumor progression. Another paradox of RT is that, while very effective at killing cancer cells, it can contribute to the formation of CAFs. This review examines how the interplay between CAFs and immune cells during RT contributes to organ fibrosis, immunosuppression, and tumor growth. We focus on targeting mechanistic pathways of CAF formation as a potentially effective strategy not only for preventing organ fibrosis, but also in hampering tumor progression in response to RT.

A novel 20-gene prognostic score in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal cancers. Known risk factors for this disease are currently insufficient in predicting mortality. In order to better prognosticate patients with PDAC, we identified 20 genes by utilizing publically available high-throughput transcriptomic data from GEO, TCGA and ICGC which are associated with overall survival and event-free survival. A score generated based on the expression matrix of these genes was validated in two independent cohorts. We find that this “Pancreatic cancer prognostic score 20 –PPS20” is independent of the confounding factors in multivariate analyses, is dramatically elevated in metastatic tissue compared to primary tumor, and is higher in primary tumors compared to normal pancreatic tissue. Transcriptomic analyses show that tumors with low PPS20 have overall more immune cell infiltration and a higher CD8 T cell/Treg ratio when compared to those with high PPS20. Analyses of proteomic data from TCGA PAAD indicated higher levels of Cyclin B1, RAD51, EGFR and a lower E-cadherin/Fibronectin ratio in tumors with high PPS20. The PPS20 score defines not only prognostic and biological sub-groups but can predict response to targeted therapy as well. Overall, PPS20 is a stronger and more robust transcriptomic signature when compared to similar, previously published gene lists.

Tumor-infiltrating CD4+ and CD8+ lymphocytes and macrophages are associated with prognostic factors in triple-negative canine mammary complex type carcinoma

This study aimed to evaluate the association of CD3⁺, CD4⁺, and CD8⁺ T cells and tumor-infiltrating macrophages (TIMs) with the clinical parameters of female dogs harboring mammary gland tumors. Thirty female dogs affected with mammary carcinomas were used, and all tumors were histologically classified as complex carcinoma and were triple-negative phenotype determined by immunohistochemistry. Freshly frozen sections were used to determine CD3⁺, CD4⁺ and CD8⁺ T cells by immunohistochemistry, and TIMs were determined by immunofluorescence assays. Ten out of the 30 dogs showed lymph node metastasis at diagnosis. Fifteen dogs had a tumor of grade I (15/30), nine (9/30) had a tumor of grade II and six (6/30) had a tumor of grade III. The mean overall survival was 680.5 days (± 200.4). Dogs with sentinel lymph node positivity (10/30) (P = .0035) and dogs that developed metastasis (P = .0001) showed a shorter survival time. In addition, dogs with a high level of inflammatory infiltrate in tumor tissues presented a shorter survival time (P = .0001) than that of other dogs. Dogs with tumors containing higher numbers of CD3+ T cells (P = .001), CD4+ T cells (P = .001), or TIM cells (P < .0001) showed a shorter survival time than that of other dogs. Our results suggested that characteristics of immune cell infiltrates, including CD3⁺ T cells, CD4⁺ T cells, and TIMs, can be used as potential prognostic indicators for predicting clinical outcomes in dogs with mammary gland tumors, particularly tumors with a complex histological subtype and triple-negative phenotype.

Consequences of EMT-Driven Changes in the Immune Microenvironment of Breast Cancer and Therapeutic Response of Cancer Cells

Epithelial-to-mesenchymal transition (EMT) is a process through which epithelial cells lose their epithelial characteristics and cell–cell contact, thus increasing their invasive potential. In addition to its well-known roles in embryonic development, wound healing, and regeneration, EMT plays an important role in tumor progression and metastatic invasion. In breast cancer, EMT both increases the migratory capacity and invasive potential of tumor cells, and initiates protumorigenic alterations in the tumor microenvironment (TME). In particular, recent evidence has linked increased expression of EMT markers such as TWIST1 and MMPs in breast tumors with increased immune infiltration in the TME. These immune cells then provide cues that promote immune evasion by tumor cells, which is associated with enhanced tumor progression and metastasis. In the current review, we will summarize the current knowledge of the role of EMT in the biology of different subtypes of breast cancer. We will further explore the correlation between genetic switches leading to EMT and EMT-induced alterations within the TME that drive tumor growth and metastasis, as well as their possible effect on therapeutic response in breast cancer.