Hepatocyte growth factor secreted by ovarian cancer cells stimulates peritoneal implantation via the mesothelial-mesenchymal transition of the peritoneum

Beyond tumor‑associated macrophages involved in spheroid formation and dissemination: Novel insights for ovarian cancer therapy (Review)

Ovarian cancer (OC) is the most common and deadly malignant tumor of the female reproductive system. When OC cells detach from the primary tumor and enter the ascitic microenvironment, they are present as individual cells or multicellular spheroids in ascites. These spheroids, composed of cancer and non‑malignant cells, are metastatic units and play a crucial role in the progression of OC. However, little is known about the mechanism of spheroid formation and dissemination. Tumor‑associated macrophages (TAMs) in the center of spheroids are key in spheroid formation and metastasis and provide a potential target for OC therapy. The present review summarizes the key biological features of spheroids, focusing on the role of TAMs in spheroid formation, survival and peritoneal metastasis, and the strategies targeting TAMs to provide new insights in treating OC.

Progress of antibody-drug conjugates (ADCs) targeting c-Met in cancer therapy; insights from clinical and preclinical studies

The cell-surface receptor tyrosine kinase c-mesenchymal-epithelial transition factor (c-Met) is overexpressed in a wide range of solid tumors, making it an appropriate target antigen for the development of anticancer therapeutics. Various antitumor c-Met-targeting therapies (including monoclonal antibodies [mAbs] and tyrosine kinases) have been developed for the treatment of c-Met-overexpressing tumors, most of which have so far failed to enter the clinic because of their efficacy and complications. Antibody-drug conjugates (ADCs), a new emerging class of cancer therapeutic agents that harness the target specificity of mAbs to deliver highly potent small molecules to the tumor with the minimal damage to normal cells, could be an attractive therapeutic approach to circumvent these limitations in patients with c-Met-overexpressing tumors. Of great note, there are currently nine c-Met-targeting ADCs being examined in different phases of clinical studies as well as eight preclinical studies for treating various solid tumors. The purpose of this study is to present a broad overview of clinical- and preclinical-stage c-Met-targeting ADCs.

Therapeutic advances of targeting receptor tyrosine kinases in cancer

Receptor tyrosine kinases (RTKs), a category of transmembrane receptors, have gained significant clinical attention in oncology due to their central role in cancer pathogenesis. Genetic alterations, including mutations, amplifications, and overexpression of certain RTKs, are critical in creating environments conducive to tumor development. Following their discovery, extensive research has revealed how RTK dysregulation contributes to oncogenesis, with many cancer subtypes showing dependency on aberrant RTK signaling for their proliferation, survival and progression. These findings paved the way for targeted therapies that aim to inhibit crucial biological pathways in cancer. As a result, RTKs have emerged as primary targets in anticancer therapeutic development. Over the past two decades, this has led to the synthesis and clinical validation of numerous small molecule tyrosine kinase inhibitors (TKIs), now effectively utilized in treating various cancer types. In this manuscript we aim to provide a comprehensive understanding of the RTKs in the context of cancer. We explored the various alterations and overexpression of specific receptors across different malignancies, with special attention dedicated to the examination of current RTK inhibitors, highlighting their role as potential targeted therapies. By integrating the latest research findings and clinical evidence, we seek to elucidate the pivotal role of RTKs in cancer biology and the therapeutic efficacy of RTK inhibition with promising treatment outcomes.

Ovarian cancer ascites confers platinum chemoresistance to ovarian cancer cells

Ovarian cancer (OC), the second most common form of gynecologic malignancy, has a poor prognosis and is often discovered in the late stages. Platinum-based chemotherapy is the first line of therapy. Nevertheless, treatment OC has proven challenging due to toxicity and the development of acquired resistance to therapy. Tumor microenvironment (TME) has been associated with platinum chemoresistance. Malignant ascites has been used as OC tumor microenvironment and its ability to induce platinum chemoresistance has been investigated. Our results suggest that exposure to OC ascites induces platinum chemoresistance in 11 of 13 cases (85 %) on OC cells. In contrast, 75 % of cirrhotic ascites (3 of 4) failed to confer platinum chemoresistance to OC cells. Cytokine array analysis revealed that IL -6 and to a lesser extent HGF were enriched in OC ascites, whereas IL -22 was enriched in cirrhotic ascites. Pharmaceutical inhibitors targeting the IL -6/ JAK pathway were mildly effective in overcoming platinum chemoresistance induced by malignant ascites. In contrast, crizotinib, an HGF/c- MET inhibitor, and 2-hydroxyestradiol (2HE2) were effective in restoring platinum chemosensitivity to OC. Our results demonstrate the importance of OC ascites in supporting platinum chemoresistance and the potential of combination therapy to restore chemosensitivity of OC cells.

The biological role of extracellular vesicles in gastric cancer metastasis

Gastric cancer (GC) is a tumor characterized by high incidence and mortality, with metastasis being the primary cause of poor prognosis. Extracellular vesicles (EVs) are an important intercellular communication medium. They contain bioactive substances such as proteins, nucleic acids, and lipids. EVs play a crucial biological role in the process of GC metastasis. Through mechanisms such as remodeling the tumor microenvironment (TME), immune suppression, promoting angiogenesis, and facilitating epithelial-mesenchymal transition (EMT) and mesothelial-mesenchymal transition (MMT), EVs promote invasion and metastasis in GC. Further exploration of the biological roles of EVs will contribute to our understanding of the mechanisms underlying GC metastasis and may provide novel targets and strategies for the diagnosis and treatment of GC. In this review, we summarize the mechanisms by which EVs influence GC metastasis from four aspects: remodeling the TME, modulating the immune system, influencing angiogenesis, and modulating the processes of EMT and MMT. Finally, we briefly summarized the organotropism of GC metastasis as well as the potential and limitations of EVs in GC.

Intraperitoneal metastasis of ovarian cancer: new insights on resident macrophages in the peritoneal cavity

Ovarian cancer metastasis occurs primarily in the peritoneal cavity. Orchestration of cancer cells with various cell types, particularly macrophages, in the peritoneal cavity creates a metastasis-favorable environment. In the past decade, macrophage heterogeneities in different organs as well as their diverse roles in tumor settings have been an emerging field. This review highlights the unique microenvironment of the peritoneal cavity, consisting of the peritoneal fluid, peritoneum, and omentum, as well as their own resident macrophage populations. Contributions of resident macrophages in ovarian cancer metastasis are summarized; potential therapeutic strategies by targeting such cells are discussed. A better understanding of the immunological microenvironment in the peritoneal cavity will provide a stepping-stone to new strategies for developing macrophage-based therapies and is a key step toward the unattainable eradication of intraperitoneal metastasis of ovarian cancer.

The role of cancer-associated mesothelial cells in the progression and therapy of ovarian cancer

Ovarian cancer is currently one of the most common malignant tumors in females with poor survival rates around the world, killing about 200,000 women each year. Although great progress has been made in treatment, most patients receiving first-line therapy experience tumor recurrence. The tumor microenvironment plays an important role in regulating the progression and prognosis of ovarian cancer. Cancer-associated mesothelial cells are the main cell population in the tumor microenvironment, which affect the progression, prognosis and chemical resistance of ovarian cancer. Cancer-associated mesothelial cells can also interact with other microenvironmental components, such as exosomes, macrophages, and adipocytes. Some studies have developed drugs targeting cancer-associated mesothelial cells in ovarian cancer to evaluate the therapeutic efficiency. In this review we highlighted the key role of cancer-associated mesothelial cells in the progression and prognosis of ovarian cancer. We also described the progress of cancer-associated mesothelial cells targeted therapy for ovarian cancer. Continued insight into the role of cancer-associated mesothelial cells in ovarian cancer will potentially contribute to the development of new and effective therapeutic regiments.

Cancer-Associated Fibroblasts: Mechanisms of Tumor Progression and Novel Therapeutic Targets

Simple Summary

The tumor microenvironment plays an important role in determining the biological behavior of several of the more aggressive malignancies. Among the various cell types evident in the tumor “field”, cancer-associated fibroblasts (CAFs) are a heterogenous collection of activated fibroblasts secreting a wide repertoire of factors that regulate tumor development and progression, inflammation, drug resistance, metastasis and recurrence. Insensitivity to chemotherapeutics and metastatic spread are the major contributors to cancer patient mortality. This review discusses the complex interactions between CAFs and the various populations of normal and neoplastic cells that interact within the dynamic confines of the tumor microenvironment with a focus on the involved pathways and genes.

Abstract

Cancer-associated fibroblasts (CAFs) are a heterogenous population of stromal cells found in solid malignancies that coexist with the growing tumor mass and other immune/nonimmune cellular elements. In certain neoplasms (e.g., desmoplastic tumors), CAFs are the prominent mesenchymal cell type in the tumor microenvironment, where their presence and abundance signal a poor prognosis in multiple cancers. CAFs play a major role in the progression of various malignancies by remodeling the supporting stromal matrix into a dense, fibrotic structure while secreting factors that lead to the acquisition of cancer stem-like characteristics and promoting tumor cell survival, reduced sensitivity to chemotherapeutics, aggressive growth and metastasis. Tumors with high stromal fibrotic signatures are more likely to be associated with drug resistance and eventual relapse. Clarifying the molecular basis for such multidirectional crosstalk among the various normal and neoplastic cell types present in the tumor microenvironment may yield novel targets and new opportunities for therapeutic intervention. This review highlights the most recent concepts regarding the complexity of CAF biology including CAF heterogeneity, functionality in drug resistance, contribution to a progressively fibrotic tumor stroma, the involved signaling pathways and the participating genes.

The Transcoelomic Ecosystem and Epithelial Ovarian Cancer Dissemination

Epithelial ovarian cancer (EOC) is considered the deadliest gynecological disease and is normally diagnosed at late stages, at which point metastasis has already occurred. Throughout disease progression, EOC will encounter various ecosystems and the communication between cancer cells and these microenvironments will promote the survival and dissemination of EOC. The primary tumor is thought to develop within the ovaries or the fallopian tubes, both of which provide a microenvironment with high risk of causing DNA damage and enhanced proliferation. EOC disseminates by direct extension from the primary tumors, as single cells or multicellular aggregates. Under the influence of cellular and non-cellular factors, EOC spheroids use the natural flow of peritoneal fluid to reach distant organs within the peritoneal cavity. These cells can then implant and seed distant organs or tissues, which develop rapidly into secondary tumor nodules. The peritoneal tissue and the omentum are two common sites of EOC metastasis, providing a microenvironment that supports EOC invasion and survival. Current treatment for EOC involves debulking surgery followed by platinum-taxane combination chemotherapy; however, most patients will relapse with a chemoresistant disease with tumors developed within the peritoneum. Therefore, understanding the role of the unique microenvironments that promote EOC transcoelomic dissemination is important in improving patient outcomes from this disease. In this review article, we address the process of ovarian cancer cellular fate at the site of its origin in the secretory cells of the fallopian tube or in the ovarian surface epithelial cells, their detachment process, how the cells survive in the peritoneal fluid avoiding cell death triggers, and how cancer- associated cells help them in the process. Finally, we report the mechanisms used by the ovarian cancer cells to adhere and migrate through the mesothelial monolayer lining the peritoneum. We also discuss the involvement of the transcoelomic ecosystem on the development of chemoresistance of EOC.

Ovarian Cancer-Driven Mesothelial-to-Mesenchymal Transition is Triggered by the Endothelin-1/β-arr1 Axis

Transcoelomic spread of serous ovarian cancer (SOC) results from the cooperative interactions between cancer and host components. Tumor-derived factors might allow the conversion of mesothelial cells (MCs) into tumor-associated MCs, providing a favorable environment for SOC cell dissemination. However, factors and molecular mechanisms involved in this process are largely unexplored. Here we investigated the tumor-related endothelin-1 (ET-1) as an inducer of changes in MCs supporting SOC progression. Here, we report a significant production of ET-1 from MCs associated with the expression of its cognate receptors, ET_A and ET_B, along with the protein β-arrestin1. ET-1 triggers MC proliferation via β-arrestin1-dependent MAPK and NF-kB pathways and increases the release of cancer-related factors. The ET_A/ET_B receptor activation supports the genetic reprogramming of mesothelial-to-mesenchymal transition (MMT), with upregulation of mesenchymal markers, as fibronectin, α-SMA, N-cadherin and vimentin, NF-kB-dependent Snail transcriptional activity and downregulation of E-cadherin and ZO-1, allowing to enhanced MC migration and invasion, and SOC transmesothelial migration. These effects are impaired by either blockade of ET_AR and ET_BR or by β-arrestin1 silencing. Notably, in peritoneal metastases both ET_AR and ET_BR are co-expressed with MMT markers compared to normal control peritoneum. Collectively, our report shows that the ET-1 axis may contribute to the early stage of SOC progression by modulating MC pro-metastatic behaviour via MMT.

Mesothelial-to-Mesenchymal Transition and Exosomes in Peritoneal Metastasis of Ovarian Cancer

Most patients with ovarian cancer (OvCA) present peritoneal disseminated disease at the time of diagnosis. During peritoneal metastasis, cancer cells detach from the primary tumor and disseminate through the intraperitoneal fluid. The peritoneal mesothelial cell (PMC) monolayer that lines the abdominal cavity is the first barrier encountered by OvCA cells. Subsequent progression of tumors through the peritoneum leads to the accumulation into the peritoneal stroma of a sizeable population of carcinoma-associated fibroblasts (CAFs), which is mainly originated from a mesothelial-to-mesenchymal transition (MMT) process. A common characteristic of OvCA patients is the intraperitoneal accumulation of ascitic fluid, which is composed of cytokines, chemokines, growth factors, miRNAs, and proteins contained in exosomes, as well as tumor and mesothelial suspended cells, among other components that vary in proportion between patients. Exosomes are small extracellular vesicles that have been shown to mediate peritoneal metastasis by educating a pre-metastatic niche, promoting the accumulation of CAFs via MMT, and inducing tumor growth and chemoresistance. This review summarizes and discusses the pivotal role of exosomes and MMT as mediators of OvCA peritoneal colonization and as emerging diagnostic and therapeutic targets.

Role of Exosomal Non-coding RNAs in Gastric Cancer: Biological Functions and Potential Clinical Applications

Gastric cancer (GC) is one of the most common fatal cancers worldwide. The communication between GC and other cells in the GC microenvironment directly affects GC progression. Recently, exosomes have been revealed as new players in intercellular communication. They play an important role in human health and diseases, including cancer, owing to their ability to carry various bioactive molecules, including non-coding RNAs (ncRNAs). NcRNAs, including micro RNAs, long non-coding RNAs, and circular RNAs, play a significant role in various pathophysiological processes, especially cancer. Increasing evidence has shown that exosomal ncRNAs are involved in the regulation of tumor proliferation, invasion, metastasis, angiogenesis, immune regulation, and treatment resistance in GC. In addition, exosomal ncRNAs have promising potential as diagnostic and prognostic markers for GC. Considering the biocompatibility of exosomes, they can also be used as biological carriers for targeted therapy. This review summarizes the current research progress on exosomal ncRNAs in gastric cancer, focusing on their biological role in GC and their potential as new biomarkers for GC and therapeutics. Our review provides insight into the mechanisms involved in GC progression, which may provide a new point cut for the discovery of new diagnostic markers and therapeutic strategies.

Exosomes Promote Pre-Metastatic Niche Formation in Gastric Cancer

Gastric cancer has a high rate of metastasis, during which pre-metastatic niches (PMN) provide a supportive environment for the upcoming tumor cells. Exosomes are bilayer vesicles secreted by cells containing biological information that mediates communication between cells. Using exosomes, gastric cancer cells establish PMN remotely in multifarious perspectives, including immunosuppression, stroma remodeling, angiogenesis, mesothelial mesenchymal transformation, and organotropism. In turn, the cell components in PMN secrete exosomes that interact with each other and provide onco-promoting signals. In this review, we highlight the role of exosomes in PMN formation in gastric cancer and discuss their potential values in gastric cancer metastasis diagnosis, prevention, and treatment.

Prognostic relevance of longitudinal HGF levels in serum of patients with ovarian cancer

The pleiotropic protein hepatocyte growth factor (HGF) is the only known ligand of the tyrosine kinase mesenchymal–epithelial transition (cMET) receptor. The HGF/cMET pathway mediates invasion and migration of ovarian cancer cells, and upregulation of HGF/cMET pathway components has been associated with poor prognosis. This study investigated the clinical relevance of circulating HGF in serum of patients with ovarian cancer. Serum HGF (sHGF) was determined by enzyme‐linked immunosorbent assay in a total of 471 serum samples from 82 healthy controls and 113 patients with ovarian cancer (88.5% with ≥ FIGO III). Patient samples were collected at primary diagnosis and at four follow‐up time points throughout treatment and at disease recurrence. Patients with ovarian cancer showed elevated median sHGF levels at primary diagnosis, and sHGF levels transiently increased after surgery and normalized in the course of chemotherapy, even dropping below initial baseline. Higher levels of sHGF were an independent predictor for shorter overall survival (OS) (a) at primary diagnosis (HR = 0.41, 95% CI: 0.22–0.78, P = 0.006), (b) at longitudinal follow‐up time points (after surgery and before/during/after chemotherapy), (c) along the patients’ individual dynamics (HR = 0.21, 95% CI: 0.07–0.63, P = 0.005), and (d) among a subgroup analysis of patients with BRCA1/2 wild‐type ovarian cancer. This is the first study proposing sHGF as an independent prognostic biomarker for ovarian cancer at primary diagnosis and in the course of platinum‐based chemotherapy, irrespective of the postoperative residual disease after surgical debulking. sHGF could be implemented into clinical diagnostics as a CA125 auxiliary tumor marker for individualized prognosis stratification and sHGF‐guided therapy monitoring.

Ovarian Cancer-Associated Mesothelial Cells: Transdifferentiation to Minions of Cancer and Orchestrate Developing Peritoneal Dissemination

Ovarian cancer has one of the poorest prognoses among carcinomas. Advanced ovarian cancer often develops ascites and peritoneal dissemination, which is one of the poor prognostic factors. From the perspective of the "seed and soil" hypothesis, the intra-abdominal environment is like the soil for the growth of ovarian cancer (OvCa) and mesothelial cells (MCs) line the top layer of this soil. In recent years, various functions of MCs have been reported, including supporting cancer in the OvCa microenvironment. We refer to OvCa-associated MCs (OCAMs) as MCs that are stimulated by OvCa and contribute to its progression. OCAMs promote OvCa cell adhesion to the peritoneum, invasion, and metastasis. Elucidation of these functions may lead to the identification of novel therapeutic targets that can delay OvCa progression, which is difficult to cure.

Isoliquiritigenin Reverses Epithelial-Mesenchymal Transition Through Modulation of the TGF-β/Smad Signaling Pathway in Endometrial Cancer

Simple Summary

The high recurrence risk and poor prognosis of metastatic endometrial cancer are the main focus of interventional therapy. In view of this, we established in vitro and in vivo metastasis models and explored the underlying mechanisms of the epithelial-mesenchymal transition (EMT) process, cell migration ability, and metastasis in response to isoliquiritigenin (ISL). The presented in vitro and in vivo preclinical studies both demonstrated that ISL efficiently suppressed endometrial cancer cell migration and reduced the HEC-1A-LUC tumor metastasis in nude mice through inhibiting TGF-β/Smad signaling pathway. These findings shed the light for further research to highlight the ISL potential in endometrial cancer metastasis.

Abstract

Endometrial cancer is a common gynecological cancer with a poor prognosis, mostly attributed to tumor metastasis. Epithelial–mesenchymal transition (EMT) can be mediated via transforming growth factor beta (TGF-β) signaling pathway, facilitating the ability of cancer cell invasion and migration. Isoliquiritigenin (ISL) is a flavonoid derived from licorice with reported antineoplastic activities. This study aims to investigate the anti-metastatic potential of ISL on endometrial cancer both in vitro and in vivo. First, human endometrial cancer cell lines (HEC-1A, Ishikawa, and RL95-2) were treated with ISL and then subjected to functional assays such as migration assay as well as molecular analyses including immunoblotting, immunofluorescence and RT-qPCR. In addition, HEC-1A-LUC cells were implanted into female nude mice and treated with ISL by intraperitoneal injection for four weeks. Results showed that ISL inhibited cell migration and reversed the effect of TGF-β on the expression of E-cadherin, N-cadherin, vimentin, α-SMA, p-Smad3, and TWIST1/2 In vitro. Interestingly, In vivo study revealed that ISL reduced peritoneal dissemination and serum level of TGF-β1, as well as decreased the expression levels of N-cadherin, p-Smad2/3, TWIST1/2, while increased E-cadherin. Overall, ISL reverses the EMT through targeting the TGF-β/Smad signaling pathway and features a potential therapeutic treatment for metastatic endometrial cancer.

Exosomal miR-106a derived from gastric cancer promotes peritoneal metastasis via direct regulation of Smad7

Peritoneal metastasis develops in more than half of patients with gastric cancer but influencing factors are poorly characterized. Exosomes are increasingly recognized as a new mediator in cancer directional metastasis through the transfer of nucleic acids or proteins to neighboring or distant cells. The role of exosomes in peritoneal metastasis and whether it could establish pre-metastatic milieu are largely unknown. Here, we assessed the migration of gastric cancer (GC) cells and identified that PKH26-labeled exosomes from GC cells can be ingested by peritoneal mesothelial cells (MCs). Additionally, miRNA (miR-106a) that highly enriched in GC-derived exosomes (GC-exos) and essential for destroying the mesothelial barrier was demonstrated through the observation of the injury of the MCs including migratory enhancement and imbalance of apoptosis and proliferation. Moreover, either stimulating miR-106a or treatment with GC-exos could inhibit the expression of Smad7, accompanied by the concurrent elevated α-SMA and fibronectin in MCs. Silencing of miR-106a abolished GC-exos-induced gene expression in MCs. The MCs regain the viability, apoptosis reduction and Smad7 expression after rescue experiment conducted in miR-106a-enriched GC-exos. Xenograft model suggested that exosomal miR-106a had a potential to promote tumor growth through targeting Smad7. Collectively, we revealed that the delivery of miR-106a from GC-exos plays a crucial role in gastric cancer peritoneal metastasis.Abbreviations: MiR-106a: microRNA-106a; Smad7: small mothers against decapentaplegic 7; GC: gastric cancer; MCs: mesothelial cells; Exos: exosomes; HG: high-differentiated gastric cancer cells; LG: low-differentiated gastric cancer cells.

The role of the peritoneal microenvironment in the pathogenesis of colorectal peritoneal carcinomatosis

Recent insights have implicated mesothelial-to-mesenchymal transition (MMT) as a mechanism by which mesothelial cells can transdifferentiate into cancer-associated fibroblasts (CAFs) in several cancers metastasizing to the peritoneum. However, this was not evaluated extensively in colorectal cancer. We examined the presumed mesothelial origin of CAFs in three types of colorectal carcinoma: conventional type adenocarcinoma, mucinous carcinoma and signet ring cell carcinoma. We evaluated the expression of mesothelial, mesenchymal, angiogenesis and colorectal cancer-related markers in peritoneal samples of twelve colorectal cancer patients with peritoneal carcinomatosis and four control patients by immunohistochemistry. We observed morphological and immunohistochemical changes in the vicinity of tumor implants in all studied colorectal cancer types. Mesothelial cells acquired a spindle-shaped myofibroblast-like morphology, lost expression of mesothelial markers, and gained expression of mesenchymal markers. Analysis of consecutive tissue sections and double staining for mesothelial and mesenchymal markers revealed overlap in expression of mesothelial and CAF markers. These findings are highly suggestive of a mesothelial origin of CAFs in peritoneal carcinomatosis in colorectal cancer. Interfering with the process of MMT might be a valuable approach in treating and preventing peritoneal carcinomatosis. Differences observed between colorectal cancer types suggest that one single strategy might not be applicable.

The exosomal integrin α5β1/AEP complex derived from epithelial ovarian cancer cells promotes peritoneal metastasis through regulating mesothelial cell proliferation and migration

PURPOSE

Epithelial ovarian cancer (EOC) is one of the most malignant cancers in the gynecologic system. Many patients are diagnosed at an advanced stage with disseminated intra-peritoneal metastases. EOC spreads via both direct extension and trans-coelomic spread. However, the interplay between human peritoneal mesothelial cells (HPMCs) and EOC cells is still ambiguous. We hypothesize that integrins (ITG) in HPMCs may play important roles in EOC metastasis.

METHODS

The expression of different integrin subtypes from HPMCs was assessed using Western blotting. The expression of integrin α5β1 (ITGA5B1) and its co-localization with asparaginyl endopeptidase (AEP) in HPMCs derived from EOC patients (EOC-HPMCs) were assessed using immunofluorescence. The role and mechanism of the exosomal ITGA5B1/AEP complex in HPMCs was assessed using both in vitro and in vivo assays. A retrospective study involving 234 cases was carried out to assess ITGA5B1 and AEP levels in circulating sera and ascites of EOC patients, as well as associations between ITGA5B1/AEP expression and overall survival.

RESULTS

We found that ITGA5B1was highly expressed and co-localized with AEP in EOC cells, and that the exosomal ITGA5B1/AEP complex secreted by EOC cells played an important role in the proliferation and migration of HPMCs. High levels of exosomal ITGA5B1/AEP were also found in circulating sera and ascites of EOC patients, and the expression of ITGA5B1/AEP in EOC tissues was found to be negatively associated with overall survival.

CONCLUSIONS

Our data indicate that EOCs may regulate the function of HPMCs through exosomal ITGA5B1/AEP, which may be crucial for peritoneal metastasis.

miR-17-5p and miR-20a-5p suppress postoperative metastasis of hepatocellular carcinoma via blocking HGF/ERBB3-NF-κB positive feedback loop

Dysregulation of microRNA (miRNA) is a frequent event in hepatocellular carcinoma (HCC), but little is known whether it is a bystander or an actual player on residual HCC metastasis during liver microenvironment remodeling initiated by hepatectomy. Methods: The differently expressed miRNAs and mRNAs were identified from RNA-seq data. Western blot, qRT-PCR, fluorescence in situ hybridization, immunofluorescence and immunohistochemical were used to detect the expression of miRNA and mRNA in cell lines and patient tissues. The biological functions were investigated in vitro and in vivo. Chromatin immunoprecipitation, proximity ligation and luciferase reporter assay were used to explore the specific binding of target genes. The expression of HGF/ERBB3 signaling was detected by Western blot. Results: In this study, HGF induced by hepatectomy was shown to promote metastasis of residual HCC cells. miR-17-5p and miR-20a-5p were confirmed to play inhibitory roles on HCC metastasis. And ERBB3 was found to be the common target of miR-17-5p and miR-20a-5p. HCC cells with lower levels of miR-17-5p and miR-20a-5p or higher level of ERBB3 were often more sensitive to response HGF stimuli and to facilitate metastatic colonization both in vitro and in vivo experimental systems. Furthermore, HGF reinforced ERBB3 expression by NF-κB transcriptional activity in a positive feedback loop. Of particular importance, HCC patients with lower levels of miR-17-5p and miR-20a-5p or higher level of ERBB3 had significantly shorter OS and PFS survivals after surgical resection. Conclusion: miR-17-5p and miR-20a-5p could suppress postoperative metastasis of hepatocellular carcinoma via blocking HGF/ERBB3-NF-κB positive feedback loop and offer a new probable strategy for metastasis prevention after HCC resection.

CircWHSC1 promotes ovarian cancer progression by regulating MUC1 and hTERT through sponging miR-145 and miR-1182

Background

Circular RNAs are key regulators in human cancers, however, there is a lack of studies on circRNAs’ specific functions in ovarian cancer.

Methods

Our study used qRT-PCR to detect the differentially expressed circRNAs between normal ovaries and ovarian cancer tissues. Cell function experiments were performed to verify the role of overexpression and silence of circWHSC1, including MTT assay, cell apoptosis assay, wound healing and Matrigel-coated Transwell assay. In vivo tumorigenesis model was constructed by subcutaneous injection in nude mice. Bioinformatics analysis predicted the possible binding sites of circWHSC1 with miRNAs, and confirmed with dual-luciferase reporter assay and RNA pull-down assay. The exosomes were extracted with ultracentrifugation. HE staining was also used to detect morphology of nude mice peritoneum.

Results

We found that circWHSC1 was up-regulated in ovarian cancer tissues, and circWHSC1 expression was higher in moderate & poor differentiation ovarian cancer tissues than in well differentiation ovarian cancer tissues. Overexpression of circWHSC1 increased cell proliferation, migration and invasion, and inhibited cell apoptosis. Silence of circWHSC1 exerted the opposite effects. Additionally, circWHSC1 could sponge miR-145 and miR-1182 and up-regulate the expression of downstream targets MUC1 and hTERT. Exosomal circWHSC1 can be transferred to peritoneal mesothelial cells and promotes peritoneal dissemination.

Conclusions

Our study demonstrates the highly expressed circWHSC1 in ovarian cancer promotes tumorigenesis by sponging miR-145 and miR-1182, and its exosome forms induce tumor metastasis through acting on peritoneal mesothelium.

circPUM1 Promotes Tumorigenesis and Progression of Ovarian Cancer by Sponging miR-615-5p and miR-6753-5p

Circular RNAs (circRNAs) have been reported to participate in the molecular mechanism of human cancers. The PUM1 gene has been confirmed to be closely related to tumorigenesis and progression of ovarian cancer. In the present study, we explored the function and underlying molecular mechanism of circPUM1 in ovarian cancer. qRT-PCR analysis showed upregulation of circPUM1 in ovarian cancer tissues compared with normal ovaries. Gain- and loss-of-function experiments indicated that circPUM1 increased cell proliferation, migration, and invasion and inhibited cell apoptosis. Intraperitoneal injection of circPUM1-knockout tumor cells in nude mice resulted in a decrease in the metastatic ability of the tumor. Bioinformatics analysis and dual-luciferase reporter assays revealed that circPUM1 upregulated the expression of nuclear factor kappa B (NF-κB) and MMP2 by sponging miR-615-5p and miR-6753-5p. Further studies showed that exosomal circPUM1 acted on peritoneal mesothelial cells and increased tumor metastasis. In conclusion, our study indicates that circPUM1 not only promotes ovarian cancer proliferation, migration and invasion, but also acts on the peritoneum and contributes to metastasis of cancer in the form of cancer-derived exosomes.

Productive Cross-Talk with the Microenvironment: A Critical Step in Ovarian Cancer Metastasis

Most ovarian cancer patients present with disseminated disease at the time of their diagnosis, which is one of the main reasons for their poor prognosis. Metastasis is a multi-step process and a clear understanding of the mechanism of regulation of these steps remains elusive. Productive reciprocal interactions between the metastasizing ovarian cancer cells and the microenvironment of the metastatic site or the tumor microenvironment play an important role in the successful establishment of metastasis. Much progress has been made in the recent past in our understanding of such interactions and the role of the cellular and acellular components of the microenvironment in establishing the metastatic tumors. This review will outline the role of the microenvironmental components of the ovarian cancer metastatic niche and their role in helping establish the metastatic tumors. Special emphasis will be given to the mesothelial cells, which are the first cells encountered by the cancer cells at the site of metastasis.

Transcriptome Profiling Reveals Matrisome Alteration as a Key Feature of Ovarian Cancer Progression

BACKGROUND

Ovarian cancer is the most lethal gynecologic malignancy. There is a lack of comprehensive investigation of disease initiation and progression, including gene expression changes during early metastatic colonization.

METHODS

RNA-sequencing (RNA-seq) was done with matched primary tumors and fallopian tubes (n = 8 pairs) as well as matched metastatic and primary tumors (n = 11 pairs) from ovarian cancer patients. Since these are end point analyses, it was combined with RNA-seq using high-grade serous ovarian cancer cells seeded on an organotypic three-dimensional (3D) culture model of the omentum, mimicking early metastasis. This comprehensive approach revealed key changes in gene expression occurring in ovarian cancer initiation and metastasis, including early metastatic colonization.

RESULTS

2987 genes were significantly deregulated in primary tumors compared to fallopian tubes, 845 genes were differentially expressed in metastasis compared to primary tumors and 304 genes were common to both. An assessment of patient metastasis and 3D omental culture model of early metastatic colonization revealed 144 common genes that were altered during early colonization and remain deregulated even in the fully developed metastasis. Deregulation of the matrisome was a key process in early and late metastasis.

CONCLUSION

These findings will help in understanding the key pathways involved in ovarian cancer progression and eventually targeting those pathways for therapeutic interventions.

Expression of connective tissue growth factor as a prognostic indicator and its possible involvement in the aggressive properties of epithelial ovarian carcinoma

Recently, connective tissue growth factor (CTGF) was demonstrated to be associated with aggressive characteristics, including proliferation, invasion and metastasis, in a number of malignancies. Here, we investigated the expression and function of CTGF in epithelial ovarian carcinoma (EOC) to clarify its molecular mechanism and clinical significance. Paraffin sections from clinical samples of EOC (N=104) were immunostained with the CTGF antibody, and then the staining positivity was semiquantitatively examined. Moreover, we explored the role of CTGF expression in the migration-promoting effect on and chemoresistance of EOC cells. The results revealed that of the 104 EOC patients, the low and high CTGF staining expression rates were 65 (62.5%) and 39 (37.5%), respectively. Patients belonging to the higher-level CTGF group showed poorer progression-free (PFS) and overall survival (OS) rates than those in the lower-level group [PFS (log-rank: P=0.0076) and OS (log-rank: P=0.0078), respectively]. Multivariable analysis showed that CTGF expression was a significant predictor of poorer PFS and OS [PFS: HR (high vs. low): 1.837, 95% CI: 1.023–3.289 (P=0.0418); OS: HR: 2.141, 95% CI: 1.077–4.296 (P=0.0300)]. In in vitro studies, in acquired paclitaxel (PTX)-resistant EOC cells, the silencing of CTGF expression led to the restoration of PTX sensitivity. Furthermore, we confirmed that the TGF-β-dependent migration-promoting effect on these CTGF-depleted cells was completely inhibited. In conclusion, the results of the present study suggest the possible involvement of CTGF in the migration-promoting effect and chemoresistance of EOC, suggesting that it may be a target for overcoming the malignant properties of EOC.

Humanized Anti-hepatocyte Growth Factor Monoclonal Antibody (YYB-101) Inhibits Ovarian Cancer Progression

Current chemotherapy regimens have certain limitations in improving the survival rates of patients with advanced ovarian cancer. Hepatocyte growth factor (HGF) is important in ovarian cancer cell migration and invasion. This study assessed the effects of YYB-101, a humanized monoclonal anti-HGF antibody, on the growth and metastasis of ovarian cancer cells. YYB-101 suppressed the phosphorylation of the HGF receptor c-MET and inhibited the migration and invasion of SKOV3 and A2780 ovarian cancer cells. Moreover, the combination of YYB-101 and paclitaxel synergistically inhibited tumor growth in an in vivo ovarian cancer mouse xenograft model and significantly increased the overall survival (OS) rate compared with either paclitaxel or YYB-101 alone. Taken together, these findings suggest that YYB-101 has therapeutic potential in ovarian cancer when combined with conventional chemotherapy agents.

The supernatant of cervical carcinoma cells lines induces a decrease in phosphorylation of STAT-1 and NF-κB transcription factors associated with changes in profiles of cytokines and growth factors in macrophages derived from U937 cells

Macrophages are presents in the tumor microenvironment and acquire different phenotypic and functional characteristics in response to microenvironmental signals. Macrophages can be differentiated into two phenotypes: M1 or pro-inflammatory (classically activated), and M2 or anti-inflammatory macrophage (alternatively activated). In response to the microenvironment, macrophages activate transcription factors as STAT1 and NF-κB-p65 for M1 macrophages or STAT3 and STAT6 for M2 macrophages; activation impacts on the profile of cytokine, chemokines and growth factors secreted by macrophages. We evaluated the effect of the supernatant of cervical-derived carcinoma cell lines HeLa, SiHa, and C-33A on the phosphorylation of transcriptional factors STAT1, NF-κB-p65, and STAT6, and their impact in the profile of secretion of cytokines and growth factors by macrophages derived from the U937 cell line. The results show that in macrophages, these supernatants induce a decrease in the phosphorylation of NF-κB-p65 and STAT1 in U937-macrophages accompanied by an increase in the secretion of IL-10, IL-6, MCP-1, and IL-8, as well as GM-CSF, G-CSF, PDGF-AA, PDGF-BB, and VEGF. Our results suggest that HeLa, SiHa, and C-33A cell lines down-regulate the activation of transcription factors characteristic of M1 macrophages (STAT1, NF-κB-p65) and induce the secretion of factors that favor tumor growth.

A Unique Pattern of Mesothelial-Mesenchymal Transition Induced in the Normal Peritoneal Mesothelium by High-Grade Serous Ovarian Cancer

The study was designed to establish whether high aggressiveness of high-grade serous ovarian cancer cells (HGSOCs), which display rapid growth, advanced stage at diagnosis and the highest mortality among all epithelial ovarian cancer histotypes, may be linked with a specific pattern of mesothelial-mesenchymal transition (MMT) elicited by these cells in normal peritoneal mesothelial cells (PMCs). Experiments were performed on primary PMCs, stable and primary ovarian cancer cells, tumors from patients with ovarian cancer, and laboratory animals. Results of in vitro and in vivo tests showed that MMT triggered by HGSOCs (primary cells and OVCAR-3 line) is far more pronounced than the process evoked by cells representing less aggressive ovarian cancer histotypes (A2780, SKOV-3). Mechanistically, HGSOCs induce MMT via Smad 2/3, ILK, TGF-β1, HGF, and IGF-1, whereas A2780 and SKOV-3 cells via exclusively Smad 2/3 and HGF. The conditioned medium from PMCs undergoing MMT promoted the progression of cancer cells and the effects exerted by the cells triggered to undergo MMT by the HGSOCs were significantly stronger than those related to the activity of their less aggressive counterparts. Our findings indicate that MMT in PMCs provoked by HGSOCs is stronger, proceeds via different mechanisms and has more procancerous characteristics than MMT provoked by less aggressive cancer histotypes, which may at least partly explain high aggressiveness of HGSOCs.

Malignant peritoneal effusion acting as a tumor environment in ovarian cancer progression: Impact and significance

Until recently, ovarian cancer research has mainly focused on the tumor cells themselves ignoring for the most part the surrounding tumor environment which includes malignant peritoneal effusions. However, one of the major conceptual advances in oncology over the last few years has been the appreciation that cancer progression cannot be explained by aberrations in cancer cells themselves and is strongly influenced by the surrounding tumor environment. The mechanisms of ovarian cancer progression differ from that of other solid tumors because ovarian cancer cells primarily disseminate within the peritoneal cavity. Malignant peritoneal effusion accumulates in the peritoneal cavity during ovarian cancer progression. These exudative fluids act as a unique tumor environment providing a framework that orchestrates cellular and molecular changes contributing to aggressiveness and disease progression. The composition of ascites, which includes cellular and acellular components, constantly adapts during the course of the disease in response to various cellular cues originating from both tumor and stromal cells. The tumor environment that represents peritoneal effusions closely constitute an ecosystem, with specific cell types and signaling molecules increasing and decreasing during the course of the disease progression creating a single complex network. Although recent advances aiming to understand the ovarian tumor environment have focused one at a time on components, the net impact of the whole environment cannot be understood simply from its parts or outside is environmental context.

Fibrosis of mesothelial cell-induced peritoneal implantation of ovarian cancer cells

Background

Peritoneal metastasis frequently occurs in patients with advanced ovarian cancer and is the main basis for a poor prognosis. The mechanism underlying preferential ovarian cancer spread to the peritoneum is not well understood.

Methods

Herein, we investigated the significance and mechanism underlying fibrosis of mesothelial cells promoting peritoneal implantation of ovarian cancer. We have assessed the mesothelial cell fibroblast transformation process in peritoneal tissues of omentum and fibrotic mesothelial cell release of chemokines to promote dissemination by scanning electron microscopy, ELISA, Western blot, and Transwell chamber assay.

Results

We showed that the fibrosis of mesothelial cells exists in the peritoneum of ovarian cancer patients with peritoneal metastasis. Fibrosis of the mesothelial cells was induced by TGF-β1, which upregulates the CXCL12–CXCR4 and CXCL16–CXCR6 axes of mesothelial cells.

Conclusion

CXCL12–CXCR4 and CXCL16–CXCR6 may be important signaling pathways closely involved in peritoneal metastasis of ovarian cancer that require further investigation. The findings may lead to developing alternative strategies aimed at preventing and treating the metastasis of ovarian cancer.

PAI-1 secreted from metastatic ovarian cancer cells triggers the tumor-promoting role of the mesothelium in a feedback loop to accelerate peritoneal dissemination

The mesothelium, covered by a continuous monolayer of mesothelial cells, is the first protective barrier against metastatic ovarian cancer. However, mesothelial cells release tumor-promoting factors that accelerate the process of peritoneal metastasis. We identified cancer-associated mesothelial cells (CAMs) that had tumor-promoting potential. Here, we found that plasminogen activator inhibitor-1 (PAI-1) induced the formation of CAMs, after which CAMs increasingly secreted the oncogenic factors interleukin-8 (IL-8) and C-X-C motif chemokine ligand 5 (CXCL5), further promoting the metastasis of ovarian cancer cells in a feedback loop. After the formation of CAMs, PAI-1 activated the nuclear factor kappa B (NFκB) pathway in the CAMs, thus transcriptionally upregulating the expression of the downstream NFκB targets IL-8 and CXCL5. Moreover, PAI-1 correlated with peritoneal metastasis in ovarian cancer patients and indicated a poor prognosis. In both ex vivo and in vivo models, after PAI-1 expression was knocked down, the metastasis of ovarian cancer cells decreased significantly. Therefore, targeting PAI-1 may provide a potential target for future therapeutics to prevent the formation of CAMs and alleviate peritoneal metastasis in ovarian cancer patients.

Exosomal miR-21-5p derived from gastric cancer promotes peritoneal metastasis via mesothelial-to-mesenchymal transition

Peritoneal metastasis is a primary metastatic route for gastric cancers, and the mechanisms underlying this process are still unclear. Peritoneal mesothelial cells (PMCs) undergo mesothelial-to-mesenchymal transition (MMT) to provide a favorable environment for metastatic cancer cells. In this study, we investigated how the exosomal miR-21-5p induces MMT and promotes peritoneal metastasis. Gastric cancer (GC)-derived exosomes were identified by transmission electron microscopy and western blot analysis, then the uptake of exosomes was confirmed by PKH-67 staining. The expression of miR-21-5p and SMAD7 were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, and the interactions between miR-21-5p and its target genes SMAD7 were confirmed by Luciferase reporter assays. The MMT of PMCs was determined by invasion assays, adhesion assays, immunofluorescent assay, and western blot. Meanwhile, mouse model of tumor peritoneal dissemination model was performed to investigate the role of exosomal miR-21-5p in peritoneal metastasis in vivo. We found that PMCs could internalize GC-derived exosomal miR-21-5p and led to increased levels of miR-21-5p in PMCs. Through various types of in vitro and in vivo assays, we confirmed that exosomal miR-21-5p was able to induce MMT of PMCs and promote tumor peritoneal metastasis. Moreover, our study revealed that this process was promoted by exosomal miR-21-5p through activating TGF-β/Smad pathway via targeting SMAD7. Altogether, our data suggest that exosomal miR-21-5p induces MMT of PMCs and promote cancer peritoneal dissemination by targeting SMAD7. The exosomal miR-21-5p may be a novel therapeutic target for GC peritoneal metastasis.

Genomics of Peritoneal Malignancies

The peritoneum protects the intraabdominal organs. This function is exploited by aggressive cancers originating from organs within the abdomen, resulting in peritoneal metastasis. We discuss genomic variants that may lead to peritoneal metastasis from multiple cancers. Peritoneal malignancies are attributed to epithelial-mesenchymal transition. These metastatic lesions harbor similar genetic mutations to the primary tumor yet may manifest clone-specific aberrations that promote propagation. Peritoneal metastasis are increasingly being treated with surgical resection as an adjunct to radiation, chemotherapy, and other biologic therapies. We describe genetic and genomic variances that are predictive markers for metastasis and burgeoning indicators for peritoneal malignancies.

Epithelial-to-Mesenchymal Transition in the Female Reproductive Tract: From Normal Functioning to Disease Pathology

Epithelial-to-mesenchymal transition (EMT) is a physiological process that is vital throughout the human lifespan. In addition to contributing to the development of various tissues within the growing embryo, EMT is also responsible for wound healing and tissue regeneration later in adulthood. In this review, we highlight the importance of EMT in the development and normal functioning of the female reproductive organs (the ovaries and the uterus) and describe how dysregulation of EMT can lead to pathological conditions, such as endometriosis, adenomyosis, and carcinogenesis. We also summarize the current literature relating to EMT in the context of ovarian and endometrial carcinomas, with a particular focus on how molecular mechanisms and the tumor microenvironment can govern cancer cell plasticity, therapy resistance, and metastasis.

The Therapeutic Potential of Targeting the HGF/cMET Axis in Ovarian Cancer

Survival rates for ovarian cancer have remained relatively stable for the past 2 decades despite advances in surgical techniques and cytotoxic chemotherapeutics, indicating a requirement for better therapies. One pathway currently proposed for targeting is the HGF/cMET pathway. Upregulated in a number of tumour types, cMET is a tyrosine kinase receptor expressed on epithelial cells. In ovarian cancer, it has been identified as highly expressed in the four major subtypes, with expression estimates ranging from 11 to 68 % of cases. HGF, the only known ligand for cMET, is found at high levels in both serum and ascites in women with ovarian cancer, and is proposed to induce both migration and metastasis. However, clinically validated biomarkers are not yet available for either HGF or cMET, preventing a clear understanding of the true rate of overexpression, or its correlation with prognosis. Despite this, a number of agents against HGF and cMET are currently being investigated in clinical trials for multiple tumour types, including ovarian. However, a lack of patient selection, biomarker usage, and post hoc analysis correlating response with expression has resulted in the majority of these trials showing little beneficial effect from these agents, indicating that additional research is required to determine their usefulness in patients with ovarian cancer.

Mesothelial-to-mesenchymal transition as a possible therapeutic target in peritoneal metastasis of ovarian cancer

Peritoneal dissemination is the primary metastatic route of ovarian cancer (OvCa), and is often accompanied by the accumulation of ascitic fluid. The peritoneal cavity is lined by mesothelial cells (MCs), which can be converted into carcinoma‐associated fibroblasts (CAFs) through mesothelial‐to‐mesenchymal transition (MMT). Here, we demonstrate that MCs isolated from ascitic fluid (AFMCs) of OvCa patients with peritoneal implants also undergo MMT and promote subcutaneous tumour growth in mice. RNA sequencing of AFMCs revealed that MMT‐related pathways – including transforming growth factor (TGF)‐β signalling – are differentially regulated, and a gene signature was verified in peritoneal implants from OvCa patients. In a mouse model, pre‐induction of MMT resulted in increased peritoneal tumour growth, whereas interfering with the TGF‐β receptor reduced metastasis. MC‐derived CAFs showed activation of Smad‐dependent TGF‐β signalling, which was disrupted in OvCa cells, despite their elevated TGF‐β production. Accordingly, targeting Smad‐dependent signalling in the peritoneal pre‐metastatic niche in mice reduced tumour colonization, suggesting that Smad‐dependent MMT could be crucial in peritoneal carcinomatosis. Together, these results indicate that bidirectional communication between OvCa cells and MC‐derived CAFs, via TGF‐β‐mediated MMT, seems to be crucial to form a suitable metastatic niche. We suggest MMT as a possible target for therapeutic intervention and a potential source of biomarkers for improving OvCa diagnosis and/or prognosis. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Preclinical development of a humanized neutralizing antibody targeting HGF

Hepatocyte growth factor (HGF) and its receptor, cMET, play critical roles in cell proliferation, angiogenesis and invasion in a wide variety of cancers. We therefore examined the anti-tumor activity of the humanized monoclonal anti-HGF antibody, YYB-101, in nude mice bearing human glioblastoma xenografts as a single agent or in combination with temozolomide. HGF neutralization, The extracellular signal-related kinases 1 and 2 (ERK1/2) phosphorylation, and HGF-induced scattering were assessed in HGF-expressing cell lines treated with YYB-101. To support clinical development, we also evaluated the preclinical pharmacokinetics and toxicokinetics in cynomolgus monkeys, and human and cynomolgus monkey tissue was stained with YYB-101 to test tissue cross-reactivity. We found that YYB-101 inhibited cMET activation in vitro and suppressed tumor growth in the orthotopic mouse model of human glioblastoma. Combination treatment with YYB-101 and temozolomide decreased tumor growth and increased overall survival compared with the effects of either agent alone. Five cancer-related genes (TMEM119, FST, RSPO3, ROS1 and NBL1) were overexpressed in YYB-101-treated mice that showed tumor regrowth. In the tissue cross-reactivity assay, critical cross-reactivity was not observed. The terminal elimination half-life was 21.7 days. Taken together, the in vitro and in vivo data demonstrated the anti-tumor efficacy of YYB-101, which appeared to be mediated by blocking the HGF/cMET interaction. The preclinical pharmacokinetics, toxicokinetics and tissue cross-reactivity data support the clinical development of YYB-101 for advanced cancer.

Progress of antibody-based inhibitors of the HGF-cMET axis in cancer therapy

Dysregulated receptor tyrosine kinase signaling in human cancer cells leads to tumor progression, invasion and metastasis. The receptor tyrosine kinase cMET is frequently overexpressed in cancer tissue, and activation of cMET signaling is related to drug resistance and the processes of carcinogenesis, invasion and metastasis. For that reason, cMET and its ligand, hepatocyte growth factor (HGF), are considered prime targets for the development of anticancer drugs. At least eight anti-cMET and four anti-HGF antibodies have been tested or are being tested in clinical trials. However, to date none of these HGF/cMET inhibitors have shown significant efficacy in clinical trials. Furthermore, no receptor tyrosine kinase inhibitors primarily targeting cMET have been approved. Given that neutralization of HGF or cMET does not cause significant adverse effects, inhibition of the HGF/cMET signaling pathway appears to be safe. In this review, we summarized the completed and ongoing clinical trials testing antibody- or protein-based anticancer drugs targeting cMET and HGF.

Effects of HGF gene polymorphisms and protein expression on transhepatic arterial chemotherapeutic embolism efficacy and prognosis in patients with primary liver cancer

OBJECTIVE

To investigate the correlations of two hepatocyte growth factor (HGF) gene polymorphisms (rs5745652 and rs2074725) and their protein expression levels with the efficacy of transhepatic arterial chemotherapeutic embolism (TACE) and prognosis in patients with primary liver cancer (PLC).

METHODS

From March 2011 to June 2012, 109 PLC patients (the case group) who chose TACE as primary treatment and 80 healthy people (the control group) who had undergone physical examination in The First Affiliated Hospital, Zhejiang University were selected during the same period. Gene polymorphisms of HGF rs5745652 and HGF rs2074725 were detected. Serum HGF level, treating efficacy, survival quality, and 3-year survival rate for PLC patients who received TACE were observed.

RESULTS

There were significant differences in genotype and allele frequencies of HGF rs5745652 and HGF rs2074725, between the case and control groups (all P<0.05). Compared with CT+TT genotype of HGF rs5745652, patients carrying CC genotype had lower serum HGF levels, higher efficacy, better survival quality, and prolonged 3-year survival rate (all P<0.05). In rs2074725, patients carrying CA+AA genotype had lower serum HGF levels, higher efficacy, better survival quality, and prolonged 3-year survival rate compared with patients carrying rs2074725 CC genotype (all P<0.05). Gene polymorphisms of HGF rs5745652 and HGF rs2074725, tumor size, and Barcelona Clinic Liver Cancer stage were independent prognostic factors for PLC (P<0.05).

CONCLUSION

Our results indicated that HGF gene polymorphisms affect TACE efficacy and survival quality of PLC patients. Patients with HGF CC genotype of rs5745652 and CA+AA genotype of rs2074725 had decreased HGF level, better curative effect, high survival quality, and a good prognosis after TACE treatment.

Research Priorities for Endometriosis

The 3rd International Consensus Workshop on Research Priorities in Endometriosis was held in São Paulo on May 4, 2014, following the 12th World Congress on Endometriosis. The workshop was attended by 60 participants from 19 countries and was divided into 5 main sessions covering pathogenesis/pathophysiology, symptoms, diagnosis/classification/prognosis, disease/symptom management, and research policy. This research priorities consensus statement builds on earlier efforts to develop research directions for endometriosis. Of the 56 research recommendations from the 2011 meeting in Montpellier, a total of 41 remained unchanged, 13 were updated, and 2 were deemed to be completed. Fifty-three new research recommendations were made at the 2014 meeting in Sao Paulo, which in addition to the 13 updated recommendations resulted in a total of 66 new recommendations for research. The research recommendations published herein, as well as those from the 2 previous papers from international consensus workshops, are an attempt to promote high-quality research in endometriosis by identifying and agreeing on key issues that require investigation. New areas included in the 2014 recommendations include infertility, patient stratification, and research in emerging nations, in addition to an increased focus on translational research. A revised and updated set of research priorities that builds on this document will be developed at the 13th World Congress on Endometriosis to be held on May 17-20, 2017, in Vancouver, British Columbia, Canada.

Diagnostic Value of Serum Angiogenesis Markers in Ovarian Cancer Using Multiplex Immunoassay

As cancer development involves pathological vessel formation, 16 angiogenesis markers were evaluated as potential ovarian cancer (OC) biomarkers. Blood samples collected from 172 patients were divided based on histopathological result: OC (n = 38), borderline ovarian tumours (n = 6), non-malignant ovarian tumours (n = 62), healthy controls (n = 50) and 16 patients were excluded. Sixteen angiogenesis markers were measured using BioPlex Pro Human Cancer Biomarker Panel 1 immunoassay. Additionally, concentrations of cancer antigen 125 (CA125) and human epididymis protein 4 (HE4) were measured in patients with adnexal masses using electrochemiluminescence immunoassay. In the comparison between OC vs. non-OC, osteopontin achieved the highest area under the curve (AUC) of 0.79 (sensitivity 69%, specificity 78%). Multimarker models based on four to six markers (basic fibroblast growth factor-FGF-basic, follistatin, hepatocyte growth factor-HGF, osteopontin, platelet-derived growth factor AB/BB-PDGF-AB/BB, leptin) demonstrated higher discriminatory ability (AUC 0.80-0.81) than a single marker (AUC 0.79). When comparing OC with benign ovarian tumours, six markers had statistically different expression (osteopontin, leptin, follistatin, PDGF-AB/BB, HGF, FGF-basic). Osteopontin was the best single angiogenesis marker (AUC 0.825, sensitivity 72%, specificity 82%). A three-marker panel consisting of osteopontin, CA125 and HE4 better discriminated the groups (AUC 0.958) than HE4 or CA125 alone (AUC 0.941 and 0.932, respectively). Osteopontin should be further investigated as a potential biomarker in OC screening and differential diagnosis of ovarian tumours. Adding osteopontin to a panel of already used biomarkers (CA125 and HE4) significantly improves differential diagnosis between malignant and benign ovarian tumours.

Therapeutic Effects of Punicalagin Against Ovarian Carcinoma Cells in Association With β-Catenin Signaling Inhibition

AIM

The aim of this study was to investigate the effects of punicalagin, a polyphenol isolated from Punica granatum, on human A2780 ovarian cancer cells in vitro.

METHODS

The viability of human A2780 ovarian cells was evaluated using Cell Counting Kit-8 assay. Cell cycle was detected with flow cytometry analysis. The protein expression levels of Bcl-2, Bax, β-catenin, cyclin D1, survivin, tissue inhibitor of metalloproteinase (TIMP)-2, and TIMP-3 were measured using Western blot analysis. Matrix metalloproteinase (MMP)-2 and MMP-9 activity was determined with gelatin zymography. Wound healing assay was used to determine cell migration.

RESULTS

Punicalagin inhibited the cell viability of A2780 cells in a dose- and time-dependent manner, and the cell cycle of A2780 cells was arrested in G1/S phase transition. The treatment also induced apoptosis as shown by the up-regulation of Bax and down-regulation of Bcl-2. On the other hand, punicalagin treatment increased the expressions of TIMP-2 and TIMP-3, decreased the activities of MMP-2 and MMP-9, and inhibited cell migration. In addition, the β-catenin pathway was suppressed as shown by the down-regulations of β-catenin and its downstream factors including cyclin D1 and survivin.

CONCLUSIONS

Punicalagin may have cancer-chemopreventive as well as cancer-chemotherapeutic effects against human ovarian cancer in humans through the inhibition of β-catenin signaling pathway.

Therapeutic Effects of Punicalagin Against Ovarian Carcinoma Cells in Association With β-Catenin Signaling Inhibition

Aim

The aim of this study was to investigate the effects of punicalagin, a polyphenol isolated from Punica granatum, on human A2780 ovarian cancer cells in vitro.

Methods

The viability of human A2780 ovarian cells was evaluated using Cell Counting Kit-8 assay. Cell cycle was detected with flow cytometry analysis. The protein expression levels of Bcl-2, Bax, β-catenin, cyclin D1, survivin, tissue inhibitor of metalloproteinase (TIMP)-2, and TIMP-3 were measured using Western blot analysis. Matrix metalloproteinase (MMP)-2 and MMP-9 activity was determined with gelatin zymography. Wound healing assay was used to determine cell migration.

Results

Punicalagin inhibited the cell viability of A2780 cells in a dose- and time-dependent manner, and the cell cycle of A2780 cells was arrested in G1/S phase transition. The treatment also induced apoptosis as shown by the up-regulation of Bax and down-regulation of Bcl-2. On the other hand, punicalagin treatment increased the expressions of TIMP-2 and TIMP-3, decreased the activities of MMP-2 and MMP-9, and inhibited cell migration. In addition, the β-catenin pathway was suppressed as shown by the down-regulations of β-catenin and its downstream factors including cyclin D1 and survivin.

Conclusions

Punicalagin may have cancer-chemopreventive as well as cancer-chemotherapeutic effects against human ovarian cancer in humans through the inhibition of β-catenin signaling pathway.

The Mesothelial Origin of Carcinoma Associated-Fibroblasts in Peritoneal Metastasis

Solid tumors are complex and unstructured organs that, in addition to cancer cells, also contain other cell types. Carcinoma-associated fibroblasts (CAFs) represent an important population in the tumor microenviroment and participate in several stages of tumor progression, including cancer cell migration/invasion and metastasis. During peritoneal metastasis, cancer cells detach from the primary tumor, such as ovarian or gastrointestinal, disseminate through the peritoneal fluid and colonize the peritoneum. Tumor cells metastasize by attaching to and invading through the mesothelial cell (MC) monolayer that lines the peritoneal cavity, then colonizing the submesothelial compact zone where CAFs accumulate. CAFs may derive from different sources depending on the surrounding metastatic niche. In peritoneal metastasis, a sizeable subpopulation of CAFs originates from MCs through a mesothelial-to-mesenchymal transition (MMT), which promotes adhesion, invasion, vascularization and subsequent tumor growth. The bidirectional communication between cancer cells and MC-derived CAFs via secretion of a wide range of cytokines, growth factors and extracellular matrix components seems to be crucial for the establishment and progression of the metastasis in the peritoneum. This manuscript provides a comprehensive review of novel advances in understanding how peritoneal CAFs provide cancer cells with a supportive microenvironment, as well as the development of future therapeutic approaches by interfering with the MMT in the peritoneum.