Hypoxia regulates ANXA1 expression to support prostate cancer cell invasion and aggressiveness

The role of ANXA1 in the tumor microenvironment

Annexin A1 (ANXA1) is widely expressed in a variety of body tissues and cells and is also involved in tumor development through multiple pathways. The invasion, metastasis, and immune escape of tumor cells depend on the interaction between tumor cells and their surrounding environment. Research shows that ANXA1 can act on a variety of cells in the tumor microenvironment (TME), and subsequently affect the proliferation, invasion and metastasis of tumors. This article describes the role of ANXA1 in the various components of the tumor microenvironment and its mechanism of action, as well as the existing clinical treatment measures related to ANXA1. These findings provide insight for the further design of strategies targeting ANXA1 for the diagnosis and treatment of malignant tumors.

Molecular Insights into the Breast and Prostate Cancer Cells in Response to the Change of Extracellular Zinc

Zinc dyshomeostasis is manifested in breast and prostate cancer cells. This study attempted to uncover the molecular details prodded by the change of extracellular zinc by employing a panel of normal and cancerous breast and prostate cell lines coupled with the top-down proteomics with two-dimensional gel electrophoresis followed by liquid chromatography-tandem mass spectrometry. The protein samples were generated from MCF-7 breast cancer cells, MCF10A normal breast cells, PC3 prostate cancer cells, and RWPE-1 normal prostate cells with or without exogenous zinc exposure in a time course (T0 and T120). By comparing the cancer cells vs respective normal epithelial cells without zinc treatment (T0), differentially expressed proteins (23 upregulated and 18 downregulated in MCF-7 cells; 14 upregulated and 30 downregulated in PC3 cells) were identified, which provides insights into the intrinsic differences of breast and prostate cancer cells. The dynamic protein landscapes in the cancer cells prodded by the extracellular zinc treatment reveal the potential roles of the identified zinc-responsive proteins (e.g., triosephosphate isomerase, S100A13, tumour proteins hD53 and hD54, and tumour suppressor prohibitin) in breast and prostate cancers. This study, for the first time, simultaneously investigated the two kinds of cancer cells related to zinc dyshomeostasis, and the findings shed light on the molecular understanding of the breast and prostate cancer cells in response to extracellular zinc variation.

Faecalibacterium prausnitzii promotes intestinal epithelial IL-18 production through activation of the HIF1α pathway

Introduction

Intestinal epithelial cells produce interleukin-18 (IL-18), a key factor in promoting epithelial barrier integrity. Here, we analyzed the potential role of gut bacteria and the hypoxia-inducible factor 1α (HIF1α) pathway in regulating mucosal IL18 expression in inflammatory bowel disease (IBD).

Methods

Mucosal samples from patients with IBD (n = 760) were analyzed for bacterial composition, IL18 levels and HIF1α pathway activation. Wild-type Caco-2 and CRISPR/Cas9-engineered Caco-2-HIF1A-null cells were cocultured with Faecalibacterium prausnitzii in a "Human oxygen-Bacteria anaerobic" in vitro system and analyzed by RNA sequencing.

Results

Mucosal IL18 mRNA levels correlated positively with the abundance of mucosal-associated butyrate-producing bacteria, in particular F. prausnitzii, and with HIF1α pathway activation in patients with IBD. HIF1α-mediated expression of IL18, either by a pharmacological agonist (dimethyloxallyl glycine) or F. prausnitzii, was abrogated in Caco-2-HIF1A-null cells.

Conclusion

Butyrate-producing gut bacteria like F. prausnitzii regulate mucosal IL18 expression in a HIF1α-dependent manner that may aid in mucosal healing in IBD.

The pro-healing effects of heparan sulfate and growth factors are enhanced by the heparinase enzyme: New association for skin wound healing treatment

Effective treatment strategies for skin wound repair are the focus of numerous studies. New pharmacological approaches appear necessary to guarantee a correct and healthy tissue regeneration. For these reasons, we purposed to investigate the effects of the combination between heparan sulfate and growth factors further adding the heparinase enzyme. Interestingly, for the first time, we have found that this whole association retains a marked pro-healing activity when topically administered to the wound. In detail, this combination significantly enhances the motility and activation of the main cell populations involved in tissue regeneration (keratinocytes, fibroblasts and endothelial cells), compared with single agents administered without heparinase. Notably, using an experimental C57BL/6 mouse model of skin wounding, we observed that the topical treatment of skin lesions with heparan sulfate + growth factors + heparinase promotes the highest closure of wounds compared to each substance mixed with the other ones in all the possible combinations. Eosin/hematoxylin staining of skin biopsies revealed that treatment with the whole combination allows the formation of a well-structured matrix with numerous new vessels. Confocal analyses for vimentin, FAP1α, CK10 and CD31 have highlighted the presence of activated fibroblasts, differentiated keratinocytes and endothelial cells at the closed region of wounds. Our results encourage defining this combined treatment as a new and appealing therapy expedient in skin wound healing, as it is able to activate cell components and promote a dynamic lesions closure.

Exosome-derived ANXA9 functions as an oncogene in breast cancer

Breast cancer (BCA) is one of the most prevalent cancers among women. Emerging evidence has revealed that Annexin A-9 (ANXA9) plays a crucial function in the development of some cancers. Notably, ANXA9 has been reported to be a new prognostic biomarker for gastric and colorectal cancers. However, its expression and biological function in BCA have not yet been investigated. Using online bioinformatics tools such as TIMER, GEPIA, HPA, and UALCAN, we predicted ANXA9 expression and its correlation with the clinicopathological characteristics of BCA patients. RT-qPCR and western blot were utilized to measure ANXA9 mRNA and ANXA9 protein expression in BCA patient tissues and cells. BCA-derived exosomes were identified by transmission electron microscopy. Functional assays were employed to evaluate the biological role of ANXA9 in BCA cell proliferation, migration, invasion, and apoptosis. A tumor xenograft in vivo model was utilized to assess the role of ANXA9 in tumor growth in mice. Bioinformatics and functional screening analysis revealed that ANXA9 was highly expressed in BCA patient tissues, with median ANXA9 expression 1.5- to 2-fold higher than in normal tissues (p < 0.05). RT-qPCR confirmed that ANXA9 expression in BCA tissues was around 1.5-fold higher than the adjacent normal tissues (p < 0.001). ANXA9 expression in different subtypes of BCA also showed a difference, and ANXA9 was found to be mostly significantly upregulated in luminal BCA relative to normal tissues or other histological subtypes (p < 0.001). Moreover, ANXA9 expression was elevated in different races, ages, clinical stages, node metastasis status, and menopause status groups relative to the normal group (p < 0.001). Furthermore, ANXA9 was found to be secreted by BCA tissue-derived exosomes and its expression was upregulated 1- to 7-fold in BCA cells treated with exosomes (p < 0.001), while its expression in MCF10A cells was not significantly altered by treatment with exosomes (p > 0.05). ANXA9 silencing induced a significant decrease of around 30% in the colony number of BCA cells (p < 0.01). The number of migrated and invaded BCA cells also decreased by around 65 and 68%, respectively, after silencing ANXA9 (p < 0.01). Tumor size was significantly reduced (nearly half) in the LV-sh-ANXA9 group relative to the LV-NC group in the xenograft model (p < 0.01), suggesting that ANXA9 silencing repressed tumor progression in BCA progression in vitro and in vivo. In conclusion, exosome-derived ANXA9 functions as an oncogene that facilitates the proliferation, migration, and invasiveness of BCA cells and enhances tumor growth in BCA development, which may provide a new prognostic and therapeutic biomarker for BCA patients.

The role of hypoxia on prostate cancer progression and metastasis

Prostate cancer is the second most common cancer diagnosed in men and the fifth-leading cause of cancer death in men worldwide. Like any solid tumor, the hypoxic microenvironment of prostatic cancer drives hypoxia-inducible factors (HIFs) to mediate cell adaptions to hypoxic conditions. HIFs direct different signaling pathways such as PI3K/Akt/mTOR, NOX, and Wnt/β-Catenin to tumor progression depending on the degree of hypoxia. HIFs regulate cytoskeleton protein expression, promoting epithelial-mesenchymal transition (EMT), which occurs when cancer cells lose cell-to-cell adhesions and start invasion and metastasis. Through activating pathways, the hypoxic microenvironment maintains the self-renewal, potency, and anti-apoptotic function of prostate cancer cells and induces tumor metastasis and transformation. These pathways could serve as a potential target for prostate cancer therapy. HIFs increase the expression of androgen receptors on cancer cells maintaining the growth and survival of prostate cancer and the development of its castration resistance. In this review, we elaborate on the role of hypoxia in prostatic cancer pathogenesis and different hypoxia-induced mechanisms.

Targeting Annexin A1 as a Druggable Player to Enhance the Anti-Tumor Role of Honokiol in Colon Cancer through Autophagic Pathway

Colon cancer is one of the most common digestive tract malignancies, having the second highest mortality rate among all tumors, with a five-year survival of advanced patients of only 10%. Efficient, targeted drugs are still lacking in treating colon cancer, so it is urgent to explore novel druggable targets. Here, we demonstrated that annexin A1 (ANXA1) was overexpressed in tumors of 50% of colon cancer patients, and ANXA1 overexpression was significantly negatively correlated with the poor prognosis of colon cancer. ANXA1 promoted the abnormal proliferation of colon cancer cells in vitro and in vivo by regulating the cell cycle, while the knockdown of ANXA1 almost totally inhibited the growth of colon cancer cells in vivo. Furthermore, ANXA1 antagonized the autophagic death of honokiol in colon cancer cells via stabilizing mitochondrial reactive oxygen species. Based on these results, we speculated that ANXA1 might be a druggable target to control colon cancer and overcome drug resistance.

An Oxidative Stress-Related Gene Signature in Granulosa Cells Is Associated with Ovarian Aging

Ovarian aging is associated with a decrease in fecundity. Increased oxidative stress of granulosa cells (GCs) is an important contributor. We thus asked whether there is an oxidative stress-related gene signature in GCs associated with ovarian aging. Public nonhuman primate (NHP) single-cell transcriptome was processed to identify GC cluster. Then, a GC signature for ovarian aging was established based on six oxidative stress-related differentially expressed genes (MAPK1, STK24, AREG, ATG7, ANXA1, and PON2). Receiver operating characteristic (ROC) analysis confirmed good discriminating capacity in both NHP single-cell and human bulk transcriptome datasets. Gene expression levels were investigated using qPCR in the human ovarian granulosa-like tumor cell line (KGN) and mouse GCs. In an oxidative stress model, KGN cells were treated with menadione (7.5 μM, 24 h) to induce oxidative stress, after which upregulation of MAPK1, STK24, ATG7, ANXA1, and PON2 and downregulation of AREG were observed (p < 0.05). In an aging model, KGN cells were continuously cultured for 3 months, leading to increased expressions of all genes (p < 0.05). In GCs of reproductively aged (8-month-old) Kunming mice, upregulated expression of Mapk1, Stk24, Atg7, and Pon2 and downregulated expression of Anxa1 and Areg were observed (p < 0.01). We therefore here identify a six-gene GC signature associated with oxidative stress and ovarian aging.

Formation of pre-metastatic bone niche in prostate cancer and regulation of traditional chinese medicine

Prostate cancer with bone metastasis has a high cancer-specific mortality. Thus, it is essential to delineate the mechanism of bone metastasis. Pre-metastatic niche (PMN) is a concept in tumor metastasis, which is characterized by tumor-secreted factors, reprogramming of stromal cells, and immunosuppression by myeloid-derived suppressor cells (MDSC), which is induced by bone marrow-derived cells (BMDC) in the target organ. However, PMN does not explain the predilection of prostate cancer towards bone metastasis. In this review, we discuss the initiation of bone metastasis of prostate cancer from the perspective of PMN and tumor microenvironment in a step-wise manner. Furthermore, we present a new concept called pre-metastatic bone niche, featuring inherent BMDC, to interpret bone metastasis. Moreover, we illustrate the regulation of traditional Chinese medicine on PMN.

Exosomal ANXA1 derived from thyroid cancer cells is associated with malignant transformation of human thyroid follicular epithelial cells by promoting cell proliferation

Exosomes are nano-sized extracellular vesicles that can be released from cancer cells. It has been shown that cancer cell-derived exosomes may be associated with carcinogenesis by transferring signaling proteins from malignant to neighboring non-malignant cells. In addition, annexin A1 (ANXA1) is a well-known oncogene, that can be released from extracellular vesicles by cancer cells. However, the role of exosomal ANXA1 in the cell-to-cell communication of thyroid cancer and thyroid follicular epithelial cells remains unclear. In the present study, the protein expression levels of ANXA1 in thyroid cancer cells and thyroid cancer cell-derived exosomes were analyzed using western blot analysis. In addition, Cell Counting Kit-8 and Transwell assays were used to determine cell viability and invasion, respectively. The protein expression levels of ANXA1 were increased in thyroid cancer tissues and thyroid cancer cell lines. In addition, overexpression of ANXA1 significantly increased the proliferation and invasion of the SW579 cells, while knockdown of ANXA1 expression exerted the opposite results. Furthermore, ANXA1 was transferred from the SW579 cells to the Nthy-ori3-1 cells via exosomes. Exosomal ANXA1 markedly promoted the proliferation, invasion and epithelial-to-mesenchymal transition of the Nthy-ori3-1 cells. In addition, SW579 cell-derived exosomal ANXA1 promoted tumor growth in a xenograft mouse model. Collectively, these findings indicated that SW579 cell-derived exosomal ANXA1 promoted thyroid cancer development and Nthy-ori3-1 cell malignant transformation. Therefore, these findings may aid in the development of effective treatment methods for thyroid cancer.

ANXA1 Contained in EVs Regulates Macrophage Polarization in Tumor Microenvironment and Promotes Pancreatic Cancer Progression and Metastasis

The tumor microenvironment (TME) is a dynamic system where nontumor and cancer cells intercommunicate through soluble factors and extracellular vesicles (EVs). The TME in pancreatic cancer (PC) is critical for its aggressiveness and the annexin A1 (ANXA1) has been identified as one of the oncogenic elements. Previously, we demonstrated that the autocrine/paracrine activities of extracellular ANXA1 depend on its presence in EVs. Here, we show that the complex ANXA1/EVs modulates the macrophage polarization further contributing to cancer progression. The EVs isolated from wild type (WT) and ANXA1 knock-out MIA PaCa-2 cells have been administrated to THP-1 macrophages finding that ANXA1 is crucial for the acquisition of a protumor M2 phenotype. The M2 macrophages activate endothelial cells and fibroblasts to induce angiogenesis and matrix degradation, respectively. We have also found a significantly increased presence of M2 macrophage in mice tumor and liver metastasis sections previously obtained by orthotopic xenografts with WT cells. Taken together, our data interestingly suggest the relevance of ANXA1 as potential diagnostic/prognostic and/or therapeutic PC marker.

Deciphering the Molecular Machinery-Influence of sE-Cadherin on Tumorigenic Traits of Prostate Cancer Cells

Simple Summary

Despite recent advances in the therapeutic management of metastasized prostate cancer, disease progression is still inevitable, with often fatal outcomes. Elucidating molecular mechanisms crucial to cancer development and progression is therefore necessary to find ways to interfere in metastatic processes and ultimately improve prognosis. Since soluble (s)E-cadherin is elevated in the serum of patients with prostate cancer, we investigated its influence on prostate cancer cell behavior in vitro. Exposure to sE-cadherin increased the systemic spread of the cells. Thus, targeting sE-cadherin might be a novel and innovative concept to treat advanced PCa.

Abstract

The serum level of soluble (s)E-cadherin is elevated in several malignancies, including prostate cancer (PCa). This study was designed to investigate the effects of sE-cadherin on the behavior of PCa cells in vitro, with the aim of identifying a potential therapeutic target. Growth as well as adhesive and motile behavior were evaluated in PC3, DU-145, and LNCaP cells. Flow cytometry was used to assess cell cycle phases and the surface expression of CD44 variants as well as α and β integrins. Confocal microscopy was utilized to visualize the distribution of CD44 variants within the cells. Western blot was applied to investigate expression of α3 and β1 integrins as well as cytoskeletal and adhesion proteins. Cell growth was significantly inhibited after exposure to 5 µg/mL sE-cadherin and was accompanied by a G0/G1-phase arrest. Adhesion of cells to collagen and fibronectin was mitigated, while motility was augmented. CD44v4, v5, and v7 expression was elevated while α3 and β1 integrins were attenuated. Blocking integrin α3 reduced cell growth and adhesion to collagen but increased motility. sE-cadherin therefore appears to foster invasive tumor cell behavior, and targeting it might serve as a novel and innovative concept to treat advanced PCa.

Crosstalk Between RPE Cells and Choroidal Endothelial Cells via the ANXA1/FPR2/SHP2/NLRP3 Inflammasome/Pyroptosis Axis Promotes Choroidal Neovascularization

One type of age-related macular degeneration (AMD), neovascular (nAMD), characterized by choroidal neovascularization (CNV), accounts for the majority of the severe central vision impairment associated with AMD. Endothelial cells (ECs) in direct contact with retinal pigment epithelial (RPE) cells are more prone to the pathological angiogenesis involved in CNV. Herein, we investigated the effect of crosstalk between RPE cells and choroidal endothelial cells (CECs) via the ANXA1/FPR2/NLRP3 inflammasome/pyroptosis axis on the development of choroidal neovascularization (CNV) in vitro and in vivo. ANXA1 expression and secretion from ARPE-19 cells were upregulated by hypoxia. FPR2 expression, especially on the plasma membrane, in HCECs was upregulated under hypoxic conditions. ANXA1 secreted from ARPE-19 cells inhibited NLRP3 inflammasome activation and NLRP3 inflammasome-mediated pyroptosis in HCECs by activating the FPR2/SHP2 axis. Moreover, ANXA1 secreted by ARPE-19 cells promoted behaviors of HCECs, including proliferation, migration, and tube formation, by activating the FPR2/SHP2 axis and inhibiting NLRP3 inflammasome-mediated pyroptosis. Inhibiting the upregulated ANXA1/FPR2/SHP2/NLRP3 inflammasome/pyroptosis axis decreased the volume of CNV. Our data suggest that the crosstalk between RPE cells and CECs via the ANXA1/FPR2/NLRP3 inflammasome/pyroptosis axis promotes CNV. This finding could identify a potential target for the prevention and treatment of CNV.

ANXA1-GSK3β interaction and its involvement in NSCLC metastasis

Although initially discovered and extensively studied for its role in inflammation, Annexin A1 (ANXA1) has been reported to be closely related to cancer in recent years, and its role in cancer is specific to tumor types and tissues. In the present study, we identified ANXA1 as an interaction partner of glycogen synthase kinase 3 beta (GSK3β), a multi-functional serine/threonine kinase tightly associated with cell fate determination and cancer, and assessed the functional significance of GSK3β-ANXA1 interaction in the metastasis of non-small cell lung cancer (NSCLC). We confirmed the interaction between GSK3β and ANXA1 in vitro and in H1299 and A549 cells by Glutathione-S-transferase (GST) pull-down assay and co-immunoprecipitation. We found that ANXA1 negatively regulated the phosphorylation of GSK3β and inhibited the epithelial-mesenchymal transformation (EMT) process and migration and invasion of NSCLC cells. By functional rescue assay, we confirmed that ANXA1 inhibited EMT through the regulation of GSK3β activity and thereby inhibited the migration and invasion of NSCLC cells. Our study sheds light on the function of ANXA1 and GSK3β and provides new elements for the understanding of NSCLC pathogenesis.

New insight into the role of ANXA1 in melanoma progression: involvement of stromal expression in dissemination

ANXA1, first described in the context of inflammation, appears to be deregulated in many cancers and increased in melanomas compared with melanocytes. To date, few studies have investigated the role of ANXA1 in melanoma progression. Furthermore, this protein is expressed by various cell types, including immune and endothelial cells. We therefore analyzed the specific roles of ANXA1 using melanoma and stromal cells in two human cell lines (A375-MA2 and SK-MEL-28) in vitro and in Anxa1 null C57Bl6/J mice bearing B16Bl6 tumors. We report decreased proliferation in both ANXA1 siRNA A375-MA2 and SK-MEL-28, but cell-dependent effects of ANXA1 in migration in vitro. However, we also observed a significant decrease of B16Bl6 tumor growth associated with a reduction of Ki-67 positive cells in Anxa1 null mice compared with wild-type mice. Interestingly, we also found a significant reduction of spontaneous metastases, which can be attributed to decreased angiogenesis concomitantly with greater immune cell presence in the Anxa1 null stromal context. This study highlights the pejorative role of ANXA1 in both tumor and stromal cells in melanoma, due to its involvement in proliferation and angiogenesis.

Reorganization of Metabolism during Cardiomyogenesis Implies Time-Specific Signaling Pathway Regulation

Understanding the cell differentiation process involves the characterization of signaling and regulatory pathways. The coordinated action involved in multilevel regulation determines the commitment of stem cells and their differentiation into a specific cell lineage. Cellular metabolism plays a relevant role in modulating the expression of genes, which act as sensors of the extra-and intracellular environment. In this work, we analyzed mRNAs associated with polysomes by focusing on the expression profile of metabolism-related genes during the cardiac differentiation of human embryonic stem cells (hESCs). We compared different time points during cardiac differentiation (pluripotency, embryoid body aggregation, cardiac mesoderm, cardiac progenitor and cardiomyocyte) and showed the immature cell profile of energy metabolism. Highly regulated canonical pathways are thoroughly discussed, such as those involved in metabolic signaling and lipid homeostasis. We reveal the critical relevance of retinoic X receptor (RXR) heterodimers in upstream retinoic acid metabolism and their relationship with thyroid hormone signaling. Additionally, we highlight the importance of lipid homeostasis and extracellular matrix component biosynthesis during cardiomyogenesis, providing new insights into how hESCs reorganize their metabolism during in vitro cardiac differentiation.

The exosome-like vesicles derived from androgen exposed-prostate stromal cells promote epithelial cells proliferation and epithelial-mesenchymal transition

Benign prostatic hyperplasia (BPH) is an age-related disease in men. Mesenchymal /stromal and epithelial cells interactions are essential to prostate functions. In this study, human nonmalignant prostate epithelial RWPE-1 cells were cocultured with testosterone (TE) -exposed prostate stromal fibroblasts WPMY-1 cells (TE-WPMY-1). The survival rate, epithelial-mesenchymal transition (EMT) and collagen deposition of RWPE-1 were observed. The expression profiles of circRNAs, lncRNAs and mRNAs in WPMY-1-derived exosome-like vesicles (WPMY-1-exo) were explored by high-throughput RNA sequencing. Firstly, both TE-WPMY-1 and TE-WPMY-1-exo significantly promoted RWPE-1 cells proliferation. Secondly, 41 circRNAs, 132 lncRNAs and 1057 mRNAs were differentially expressed (DE) between TE-WPMY-1-exo and the control. Functional enrichment analyses, co-expression analyses and quantitative real-time PCR verification showed that the DE RNAs played important roles in cell proliferation, structure, phenotype and fibrosis. Lastly, blocking WPMY-1-exo biogenesis/release by GW4869 can attenuate TE-WPMY-1-stimulated RWPE-1 cells EMT and collagen deposition. Taken together, our results indicated that WPMY-1-exo modulated the phenotypes changes and collagen deposition of prostate epithelial cells. It provided a novel basis for understanding the underlying mechanisms of RWPE-1 cells EMT and fibrosis induced by WPMY-1 in BPH.

Annexin A1 is a potential biomarker of bone metastasis in small cell lung cancer

Small cell lung cancer (SCLC) is a subtype of lung cancer with a poor prognosis, with bone metastasis being one of the main causes of treatment failure. Therefore, investigating new biomarkers associated with bone metastasis may result in positive treatment outcomes. The present study detected the expression levels of annexin A1 (ANXA1) in the serum of 82 patients with SCLC using ELISA. ANXA1 expression in patients with SCLC with bone metastasis was significantly higher compared with that in patients without bone metastasis. Receiver operating characteristic analysis revealed that ANXA1 expression was significant in the diagnosis of bone metastasis in SCLC. ANXA1 was inhibited in SBC-5 cells and overexpressed in SBC-3 cells. Results revealed that ANXA1 was able to enhance SCLC cell proliferation, invasion, migration and bone adhesion in vitro. In vivo xenograft bone metastasis assays indicated that ANXA1 had the potential to promote the bone-metastasis ability of SCLC cells in NOD/SCID mice. Furthermore, ANXA1 increased parathyroid hormone-related protein secretion and enhanced Smad2 phosphorylation following TGF-β treatment in SCLC cells. Overall, ANXA1 may be involved in the pathogenesis of bone metastasis in SCLC and may be a potential biomarker for the diagnosis of SCLC.

Annexin A1 Released in Extracellular Vesicles by Pancreatic Cancer Cells Activates Components of the Tumor Microenvironment, through Interaction with the Formyl-Peptide Receptors

Pancreatic cancer (PC) is one of the most aggressive cancers in the world. Several extracellular factors are involved in its development and metastasis to distant organs. In PC, the protein Annexin A1 (ANXA1) appears to be overexpressed and may be identified as an oncogenic factor, also because it is a component in tumor-deriving extracellular vesicles (EVs). Indeed, these microvesicles are known to nourish the tumor microenvironment. Once we evaluated the autocrine role of ANXA1-containing EVs on PC MIA PaCa-2 cells and their pro-angiogenic action, we investigated the ANXA1 paracrine effect on stromal cells like fibroblasts and endothelial ones. Concerning the analysis of fibroblasts, cell migration/invasion, cytoskeleton remodeling, and the different expression of specific protein markers, all features of the cell switching into myofibroblasts, were assessed after administration of wild type more than ANXA1 Knock-Out EVs. Interestingly, we demonstrated a mechanism by which the ANXA1-EVs complex can stimulate the activation of formyl peptide receptors (FPRs), triggering mesenchymal switches and cell motility on both fibroblasts and endothelial cells. Therefore, we highlighted the importance of ANXA1/EVs-FPR axes in PC progression as a vehicle of intercommunication tumor cells-stroma, suggesting a specific potential prognostic/diagnostic role of ANXA1, whether in soluble form or even if EVs are captured in PC.

Application of small molecule FPR1 antagonists in the treatment of cancers

The formylpeptide receptor-1 (FPR1) is a member of the chemotactic GPCR-7TM formyl peptide receptor family, whose principle function is in trafficking of various leukocytes into sites of bacterial infection and inflammation. More recently, FPR1 has been shown to be expressed in different types of cancer and in this context, plays a significant role in their expansion, resistance and recurrence. ICT12035 is a selective and potent (30 nM in calcium mobilisation assay) small molecule FPR1 antagonist. Here, we demonstrate the efficacy of ICT12035, in a number of 2D and 3D proliferation and invasion in vitro assays and an in vivo model. Our results demonstrate that targeting FPR1 by a selective small molecule antagonist, such as ICT12035, can provide a new avenue for the treatment of cancers.

Inhibition of Androgen Receptor Signaling Promotes Prostate Cancer Cell Migration via Upregulation of Annexin A1 Expression

BACKGROUND

Recent studies indicate that androgen deprivation therapy (ADT), the main therapeutic approach for metastatic prostate cancer (PCa), accelerates PCa invasion and metastasis. Annexin A1 (ANXA1) is a Ca²⁺-regulated phospholipid-binding protein that can promote PCa migration and invasion.

AIM OF THE STUDY

The aim of this study is to determine whether ANXA1 is regulated by ADT and participates in PCa progression after ADT, and to explore the possible mechanism of ANXA1-mediated PCa migration.

METHODS

Expression of ANXA1 and androgen receptor (AR) in PCa cell lines and tissues was detected, and the association between these two proteins were analyzed. Expression of ANXA1 was evaluated after AR knockdown or AR inhibition in PCa cell lines. Cell migration of PCa cell liness after ANXA1 knockdown or overexpression was determined by in vitro migration assay. Transcriptome analysis was used to explore the possible mechanism of ANXA1-mediated PCa migration.

RESULTS

ANXA1 expression in PCa cell lines and tissues was reversely associated with AR. In vitro studies revealed an increase in ANXA1 expression after AR knockdown or treatment with AR antagonist. Moreover, functional assays indicated that ANXA1 knockdown in PCa cells significantly inhibited cell migration, while ANXA1 overexpression in PCa cells significantly accelerated cell migration. Transcriptome analysis showed that ANXA1 regulated multiple genes involved in cell junction organization, such as CADM1, LIMCH1 and PPM1F.

CONCLUSIONS

Our results indicate that ADT might accelerate PCa metastasis via ANXA1 expression and PCa cell migration.

Annexin A1 promotes the nuclear localization of the epidermal growth factor receptor in castration-resistant prostate cancer

Epidermal growth factor receptor is a cancer driver whose nuclear localization has been associated with the progression of prostate cancer to the castration-resistant phenotype. Previous reports indicated a functional interaction between this receptor and the protein Annexin A1, which has also been associated with aggressive tumors. The molecular pathogenesis of castration-resistant prostate cancer remains largely unresolved, and herein we have demonstrated the correlation between the expression levels and localization of the epidermal growth factor receptor and Annexin A1 in prostate cancer samples and cell lines. Interestingly, a higher expression of both proteins was detected in castration-resistant prostate cancer cell lines and the strongest correlation was seen at the nuclear level. We verified that Annexin A1 interacts with the epidermal growth factor receptor, and by using prostate cancer cell lines knocked down for Annexin A1, we succeeded in demonstrating that Annexin A1 promotes the nuclear localization of epidermal growth factor receptor. Finally, we showed that Annexin A1 activates an autocrine signaling in castration-resistant prostate cells through the formyl peptide receptor 1. The inhibition of such signaling by Cyclosporin H inhibits the nuclear localization of epidermal growth factor receptor and its downstream signaling. The present work sheds light on the functional interaction between nuclear epidermal growth factor receptor and nuclear Annexin A1 in castration-resistant prostate cancer. Therefore, strategies to inhibit the nuclear localization of epidermal growth factor receptor through the suppression of the Annexin A1 autocrine loop could represent an important intervention strategy for castration-resistant prostate cancer.

Overexpression of Annexin A1 Is an Independent Predictor of Longer Overall Survival in Epithelial Ovarian Cancer

BACKGROUND

Epithelial ovarian cancer (EOC) is the major gynecological cause of cancer deaths. Annexin A1 (ANXA1) protein has been implicated in the aggressiveness of several cancer types.

MATERIALS AND METHODS

This study retrospectively assessed ANXA1 expression in epithelial cells of 156 pre-chemotherapy EOC samples and 34 normal ovarian samples from patients treated at Salah Azaiez Institute. Using immunohistochemistry, ANXA1 expression was compared in normal versus cancer samples; correlations with clinicopathological features, including overall survival, were sought.

RESULTS

Fifty-two percent of tumor samples showed epithelial ANXA1 staining versus only 26% of normal samples (Fisher's exact test, p=0.00794). Epithelial ANXA1 expression was correlated with better overall survival in both univariate and multivariate analyses.

CONCLUSION

The possible contribution of ANXA1 overexpression to EOC outcome may be relevant to therapeutic strategies.

Suppression of TRPM7 Inhibited Hypoxia-Induced Migration and Invasion of Androgen-Independent Prostate Cancer Cells by Enhancing RACK1-Mediated Degradation of HIF-1α

Transient receptor potential melastatin subfamily member 7 (TRPM7) was essential in the growth and metastatic ability of prostate cancer cells. However, the effects and the relevant molecular mechanisms of TRPM7 on metastasis of prostate cancer under hypoxic atmosphere remain unclear. This study investigated the role of TRPM7 in the metastatic ability of androgen-independent prostate cancer cells under hypoxia. First, data mining was carried out to disclose the relationship between the TRPM7 gene level and the survival of prostate cancer patients. Specific siRNAs were used to knockdown target genes. Western blotting and qPCR were employed to determine protein and gene expression, respectively. The gene transcription activity was evaluated by luciferase activity assay of promoter gene. The protein interaction was determined by coimmunoprecipitation. Wound healing and transwell assays were employed to evaluated cell migration and invasion, respectively. Open access database results showed that high expression of TRPM7 was closely related to the poor survival of prostate cancer patients. Hypoxia simultaneously increased TRPM7 expression and induced HIF-1α accumulation in androgen-independent prostate cancer cells. Knockdown of TRPM7 significantly promoted HIF-1α degradation through the proteasome and inhibited EMT changes in androgen-independent prostate cancer cells under hypoxic condition. Moreover, TRPM7 knockdown increased the phosphorylation of RACK1 and strengthened the interaction between RACK1 and HIF-1α but attenuated the binding of HSP90 to HIF-1α. Whereas knockdown of RACK1 increased the binding of HSP90 to HIF-1α. Furthermore, both TRPM7 and HIF-1α knockdown significantly suppressed hypoxia-induced Annexin A1 protein expression, and suppression of HIF-1α/Annexin A1 signaling significantly inhibited hypoxia-induced cell migration and invasion of androgen-independent prostate cancer cells. Our findings demonstrate that TRPM7 knockdown promotes HIF-1α degradation via an oxygen-independent mechanism involving increased binding of RAKC1 to HIF-1α, and TRPM7-HIF-1α-Annexin A1 signaling axis plays a crucial role in the EMT, cell migration, and invasion of androgen-independent prostate cancer cells under hypoxic conditions.

Transcriptional regulation of FoxM1 by HIF‑1α mediates hypoxia‑induced EMT in prostate cancer

Hypoxia is a tumorigenesis-related microenvironment change which usually occurs in the earliest stage of prostate cancer (PCa) development. Accumulating evidence has demonstrated that hypoxia/hypoxia-inducing factor (HIF) is involved in the induction of epithelial-mesenchymal transition (EMT) and increased metastatic potential in PCa. However, the mechanism by which hypoxia/HIF regulates EMT remains unclear. In the present study, we demonstrated the molecular mechanisms of hypoxia-induced EMT in PCa, focusing on HIF-1α/Forkhead box M1 (FoxM1) signaling pathway. PCa PC3 and DU145 cell lines were used as the model system in vitro. Our data revealed that hypoxia induced EMT in PCa cells. Bioinformatics analysis identified the possible association between HIF-1α and FoxM1. Additionally, FoxM1 was significantly associated with PCa development and Gleason scores of PCa. Exposure to hypoxia resulted in the increased expression of HIF-1α and FoxM1. Genetic knockdown FoxM1 abolished hypoxia-induced EMT in PCa, while exogenous overexpression of FoxM1 facilitated hypoxia-induced EMT. Furthermore, the increase of FoxM1 during hypoxia was due to the transcriptional regulation on the FoxM1 promoter by HIF-1α. We also confirmed the binding site of HIF-1α on the FoxM1 promoter by different lengths promoter sequences. These findings provide new insights into how EMT is regulated in PCa under hypoxic stress. It is worthwhile to investigate in future that inhibition of FoxM1 as a potential target may be an effective therapeutic strategy against PCa.

Comparative RNA-seq analysis reveals dys-regulation of major canonical pathways in ERG-inducible LNCaP cell progression model of prostate cancer

Prostate Cancer (CaP) is the second leading cause of cancer related death in USA. In human CaP, gene fusion between androgen responsive regulatory elements at the 5'-untranslated region of TMPRSS2 and ETS-related genes (ERG) is present in at least 50% of prostate tumors. Here we have investigated the unique cellular transcriptome associated with over-expression of ERG in ERG-inducible LNCaP cell model system of human CaP. Comprehensive transcriptome analyses reveal a distinct signature that distinguishes ERG dependent and independent CaP in LNCaP cells. Our data highlight a significant heterogeneity among the transcripts. Out of the 526 statistically significant differentially expressed genes, 232 genes are up-regulated and 294 genes are down-regulated in response to ERG. These ERG-associated genes are linked to several major cellular pathways, cell cycle regulation being the most significant. Consistently our data indicate that ERG plays a key role in modulating the expression of genes required for G1 to S phase transition, particularly those that affect cell cycle arrest at G1 phase. Moreover, cell cycle arrest in response to ERG appears to be promoted by induction of p21 in a p53 independent manner. These findings may provide new insights into mechanisms that promote growth and progression of CaP.

Up-regulation of ANXA1 suppresses polymorphonuclear neutrophil infiltration and myeloperoxidase activity by activating STAT3 signaling pathway in rat models of myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) is recognized as a major cause of morbidity and mortality which is commonly associated with coronary artery disease. In recent studies, annexin A1 gene (ANXA1) has been discovered to be involved in the treatment for MIRI. In this study, the primary focus was on the molecular mechanism of ANXA1 in polymorphonuclear neutrophil (PMN) infiltration and myeloperoxidase (MPO) activity in rats with MIRI. Initially, microarray analysis was carried out in order to identify differentially expressed genes. Moreover, a rat model of MIRI was established for evaluating the expression of ANXA1, signal transducer and activator of transcription 3 (STAT3) and vascular endothelial growth factor (VEGF) in myocardial tissues. Following this, the ANXA1 vector, siRNA-ANXA1, and Stattic (inhibitor of STAT3 signaling pathway) were utilized for analyzing the regulatory role of ANXA1 in physiological indexes, hemodynamic parameters, inflammatory factors, myocardial infarct size, MPO activity, PMN infiltration, and apoptosis of PMNs. Furthermore, the relationship between ANXA1 and STAT3 signaling pathway was analyzed. Initially, a reduction in the expression of ANXA1, STAT3 and VEGF in myocardial tissues of MIRI rats was found. To elaborate, overexpressed ANXA1 inhibited levels of inflammatory factors, the activation of PMN infiltration, reduced the degree of PMN infiltration, and decreased the apoptosis of PMNs. More importantly, down-regulated ANXA1 inhibited the activation of STAT3 signaling pathway, which thereby suppressed VEGF expression. With this all taken into account, the present study presents that up-regulated ANXA1 inhibits PMN infiltration and MPO activity by activation of STAT3 signaling pathway in rats with MIRI.

Hypoxia Patterns in Primary and Metastatic Prostate Cancer Environments

Metastatic dissemination continues to be a major cause of prostate cancer (PCa) mortality, creating a compelling need to understand factors that play a role in the metastatic cascade. Since hypoxia plays an important role in PCa aggressiveness, we characterized patterns of hypoxia in the primary tumor and metastatic environments of a human PCa xenograft. We previously developed and characterized an imaging strategy based on the hypoxia response element (HRE)-driven expression of long-lived enhanced green fluorescent protein (EGFP) and short-lived luciferase (luc) fused to the oxygen-dependent degradation domain in human PCa PC-3 cells. Both reporter proteins were placed under the transcriptional control of a five-tandem repeat HRE sequence. PC-3 cells also constitutively expressed the tdTomato red fluorescent protein, allowing cancer cell detection in vivo. This "timer" strategy can provide information on the temporal evolution of HIF activity and hypoxia in tumors. Here, for the first time, we performed in vivo and ex vivo imaging of this dual HIF reporter system in PC-3 metastatic tumors implanted orthotopically in the prostate and PC-3 nonmetastatic tumors implanted subcutaneously. We observed distinct patterns of EGFP and luc expression in subcutaneous and orthotopic tumors, and in metastatic nodules, that provide new insights into the presence of hypoxia at primary and metastatic tumor sites, and of the role of hypoxia in metastasis.

Contribution of FPR and TLR9 to hypoxia-induced chemoresistance of ovarian cancer cells

Background/purpose

The aim of this study was to investigate the role and mechanisms of the formyl peptide receptor (FPR) and the toll-like receptor 9 (TLR9) in hypoxia-induced chemoresistance of human ovarian cancer cells.

Materials and methods

SKOV3 cells were exposed to hypoxia for 24 hours, the supernatant was collected to stimulate normoxia-cultured SKOV3, and the inhibition rate of cell growth was detected with CCK8 test. The agonist of TLR9 CpG ODN and the agonist of FPR fMLF were applied to investigate the chemosensitivity of SKOV3 cells to cisplatin. The cells were also treated with FPR antagonist t-Boc or TLR9 antagonist CQ. Western blot was applied to detect protein levels of FPR, TLR9, MRP, P-gp, p53 and Beclin-1. Immunofluorescence staining was applied to observe the distribution of TLR9 in SKOV3 cells.

Results

Hypoxia exposure reduced the inhibition rate of cisplatin on SKOV3 cells. WB showed that FPR and TLR9 were expressed in human ovarian cancer tissues and SKOV3 cells, and the levels were increased with longer hypoxia time. After SKOV3 was stimulated with fMLF or ODN2006, cisplatin-induced inhibition rate was significantly decreased. tBoc and CQ significantly attenuated hypoxia supernatant-induced chemoresistance of SKOV3 cells. Hypoxia supernatants significantly increased MRP, P-gp, p53 and Beclin-1 proteins in SKOV3 cells, which were significantly reduced by tBoc.

Conclusion

Hypoxia upregulates the expression of FPR and TLR9, and promotes the release of ligands for both receptors in human ovarian cancer cell line. FPR and TLR9 may be noval targets for chemosensitizing to ovarian cancer cells.

Annexin A1 May Induce Pancreatic Cancer Progression as a Key Player of Extracellular Vesicles Effects as Evidenced in the In Vitro MIA PaCa-2 Model System

Pancreatic Cancer (PC) is one of the most aggressive malignancies worldwide. As annexin A1 (ANXA1) is implicated in the establishment of tumour metastasis, the role of the protein in PC progression as a component of extracellular vesicles (EVs) has been investigated. EVs were isolated from wild type (WT) and ANXA1 knock-out (KO) PC cells and then characterised by multiple approaches including Western blotting, Field Emission-Scanning Electron Microscopy, and Dynamic Light Scattering. The effects of ANXA1 on tumour aggressiveness were investigated by Wound-Healing and invasion assays and microscopic analysis of the Epithelial to Mesenchymal Transition (EMT). The role of ANXA1 on angiogenesis was also examined in endothelial cells, using similar approaches. We found that WT cells released more EVs enriched in exosomes than those from cells lacking ANXA1. Notably, ANXA1 KO cells recovered their metastatic potential only when treated by WT EVs as they underwent EMT and a significant increase of motility. Similarly, human umbilical vein endothelial cells (HUVEC) migrated and invaded more rapidly when treated by WT EVs whereas ANXA1 KO EVs weakly induced angiogenesis. This study suggests that EVs-related ANXA1 is able to promote cell migration, invasion, and angiogenesis, confirming the relevance of this protein in PC progression.

Formyl-Peptide Receptors in Infection, Inflammation, and Cancer

Formyl-peptide receptors (FPRs) recognize bacterial and mitochondrial formylated peptides as well as endogenous non-formylated peptides and even lipids. FPRs are expressed on various host cell types but most strongly on neutrophils and macrophages. After the discovery of FPRs on leukocytes, it was assumed that these receptors predominantly govern a proinflammatory response resulting in chemotaxis, degranulation, and oxidative burst during infection. However, it is clear that the activation of FPRs has more complex consequences and can also promote the resolution of inflammation. Recent studies have highlighted associations between FPR function and inflammatory conditions, including inflammatory disorders, cancer, and infection. In this review we discuss these recent findings.

Differentially expressed proteins in positive versus negative HNSCC lymph nodes

Background

Lymph node metastasis is one of the most important prognostic factors in head and neck squamous cell carcinomas (HNSCCs) and critical for delineating their treatment. However, clinical and histological criteria for the diagnosis of nodal status remain limited. In the present study, we aimed to characterize the proteomic profile of lymph node metastasis from HNSCC patients.

Methods

In the present study, we used one- and two-dimensional electrophoresis and mass spectrometry analysis to characterize the proteomic profile of lymph node metastasis from HNSCC.

Results

Comparison of metastatic and non-metastatic lymph nodes showed 52 differentially expressed proteins associated with neoplastic development and progression. The results reinforced the idea that tumors from different anatomical subsites have dissimilar behaviors, which may be influenced by micro-environmental factor including the lymphatic network. The expression pattern of heat shock proteins and glycolytic enzymes also suggested an effect of the lymph node environment in controlling tumor growth or in metabolic reprogramming of the metastatic cell. Our study, for the first time, provided direct evidence of annexin A1 overexpression in lymph node metastasis of head and neck cancer, adding information that may be useful for diagnosing aggressive disease.

Conclusions

In brief, this study contributed to our understanding of the metastatic phenotype of HNSCC and provided potential targets for diagnostic in this group of carcinomas.

Electronic supplementary material

The online version of this article (10.1186/s12920-018-0382-6) contains supplementary material, which is available to authorized users.

miR-196a Is Able to Restore the Aggressive Phenotype of Annexin A1 Knock-Out in Pancreatic Cancer Cells by CRISPR/Cas9 Genome Editing

Annexin A1 (ANXA1) is a Ca²⁺-binding protein that is involved in pancreatic cancer (PC) progression. It is able to mediate cytoskeletal organization maintaining a malignant phenotype. Our previous studies showed that ANXA1 Knock-Out (KO) MIA PaCa-2 cells partially lost their migratory and invasive capabilities and also the metastatization process appeared affected in vivo. Here, we investigated the microRNA (miRNA) profile in ANXA1 KO cells finding that the modification in miRNA expression suggests the significant involvement of ANXA1 in PC development. In this study, we focused on miR-196a which appeared down modulated in absence of ANXA1. This miRNA is a well known oncogenic factor in several tumour models and it is able to trigger the agents of the epithelial to mesenchymal transition (EMT), like ANXA1. Our results show that the reintroduction in ANXA1 KO cells of miR-196a through the mimic sequence restored the early aggressive phenotype of MIA PaCa-2. Then, ANXA1 seems to support the expression of miR-196a and its role. On the other hand, this miRNA is able to mediate cytoskeletal dynamics and other protein functions promoting PC cell migration and invasion. This work describes the correlation between ANXA1 and specific miRNA sequences, particularly miR-196a. These results could lead to further information on ANXA1 intracellular role in PC, explaining other aspects that are apart from its tumorigenic behaviour.

Analysis of differentially expressed genes, clinical value and biological pathways in prostate cancer

The present study aimed to investigate the gene expression changes in prostate cancer (PC) and screen the hub genes and associated pathways of PC progression. The authors employed integrated analysis of GSE46602 downloaded from the Gene Expression Omnibus and The Cancer Genome Atlas databases to identify 484 consensual differentially expressed genes (DEGs) in PC, when compared with adjacent normal tissue samples. Functional annotation and pathway analysis were performed. The protein-protein interaction (PPI) networks and module were constructed. RT-qPCR was used to validate the results in clinical PC samples. Survival analysis of hub genes was performed to explore their clinical value. GO analysis results revealed that DEGs were significantly enriched in negative regulation of nitrobenzene metabolic process, extracellular space and protein homodimerization activity. KEGG pathway analysis results revealed that DEGs were most significantly enriched in focal adhesion. The top 10 hub genes were identified to be hub genes from the PPI network, and the model revealed that these genes were enriched in various pathways, including neuroactive ligand-receptor interaction, p53 and glutathione metabolism signaling pathways. RT-qPCR results validated that expression levels of eight genes (PIK3R1, BIRC5, ITGB4, RRM2, TOP2A, ANXA1, LPAR1 and ITGB8) were consistent with the bioinformatics analysis. ITGB4 and RRM2 with genetic alterations exhibited association with a poorer survival rate, compared with those without alterations. These results revealed that PC-related genes and pathways have an important role in tumor expansion, metastasis and prognosis. In summary, these hub genes and related pathways may act as biomarkers or therapeutic targets for PC.

The Pharmaceutical Device Prisma® Skin Promotes in Vitro Angiogenesis through Endothelial to Mesenchymal Transition during Skin Wound Healing

Glycosaminoglycans are polysaccharides of the extracellular matrix supporting skin wound closure. Mesoglycan is a mixture of glycosaminoglycans such as chondroitin-, dermatan-, heparan-sulfate and heparin and is the main component of Prisma^® Skin, a pharmaceutical device developed by Mediolanum Farmaceutici S.p.a. Here, we show the in vitro effects of this device in the new vessels formation by endothelial cells, since angiogenesis represents a key moment in wound healing. We found a strong increase of migration and invasion rates of these cells treated with mesoglycan and Prisma^® Skin which mediate the activation of the pathway triggered by CD44 receptor. Furthermore, endothelial cells form longer capillary-like structures with a great number of branches, in the presence of the same treatments. Thus, the device, thanks to the mesoglycan, leads the cells to the Endothelial-to-Mesenchymal Transition, suggesting the switch to a fibroblast-like phenotype, as shown by immunofluorescence assays. Finally, we found that mesoglycan and Prisma^® Skin inhibit inflammatory reactions such as nitric oxide secretion and NF-κB nuclear translocation in endothelial cells and Tumor Necrosis Factor-α production by macrophages. In conclusion, based on our data, we suggest that Prisma^® Skin may be able to accelerate angiogenesis in skin wound healing, and regulate inflammation avoiding chronic, thus pathological, responses.