Alternatively activated macrophage-derived secretome stimulates ovarian cancer spheroid spreading through a JAK2/STAT3 pathway

Hyperinflammatory repolarisation of ovarian cancer patient macrophages by anti-tumour IgE antibody, MOv18, restricts an immunosuppressive macrophage:Treg cell interaction

Ovarian cancer is the most lethal gynaecological cancer and treatment options remain limited. In a recent first-in-class Phase I trial, the monoclonal IgE antibody MOv18, specific for the tumour-associated antigen Folate Receptor-α, was well-tolerated and preliminary anti-tumoural activity observed. Pre-clinical studies identified macrophages as mediators of tumour restriction and pro-inflammatory activation by IgE. However, the mechanisms of IgE-mediated modulation of macrophages and downstream tumour immunity in human cancer remain unclear. Here we study macrophages from patients with epithelial ovarian cancers naive to IgE therapy. High-dimensional flow cytometry and RNA-seq demonstrate immunosuppressive, FcεR-expressing macrophage phenotypes. Ex vivo co-cultures and RNA-seq interaction analyses reveal immunosuppressive associations between patient-derived macrophages and regulatory T (Treg) cells. MOv18 IgE-engaged patient-derived macrophages undergo pro-inflammatory repolarisation ex vivo and display induction of a hyperinflammatory, T cell-stimulatory subset. IgE reverses macrophage-promoted Treg cell induction to increase CD8+ T cell expansion, a signature associated with improved patient prognosis. On-treatment tumours from the MOv18 IgE Phase I trial show evidence of this IgE-driven immune signature, with increased CD68+ and CD3+ cell infiltration. We demonstrate that IgE induces hyperinflammatory repolarised states of patient-derived macrophages to inhibit Treg cell immunosuppression. These processes may collectively promote immune activation in ovarian cancer patients receiving IgE therapy.

A positive feedback loop of OTUD1 and c-Jun driven by leptin expedites stemness maintenance in ovarian cancer

Cancer stem cells (CSCs) are closely associated with drug resistance and recurrence in ovarian cancer patients. Although leptin is a high-risk factor for ovarian cancer and promotes stemness maintenance, a therapeutic strategy that counteracts the downstream signaling pathway of leptin remains elusive. Herein, the deubiquitinase OTUD1 was identified as a critical regulator of leptin in maintaining OCSCs properties. Mechanistically, leptin treatment significantly increased the chromatin enrichment of the transcription factor c-Jun, including the OTUD1 gene enhancer, which was sufficient to increase the OTUD1 protein level and subsequently cause OTUD1 aggresome formation, ASK1 recruitment and JNK/c-Jun pathway activation. The resultant positive feedback loop of c-Jun and OTUD1 was required for OCSCs stemness maintenance. Notably, the disruption of the positive feedback loop by targeting c-Jun or ASK1/JNK with T-5224, selonsertib, or ibrutinib markedly inhibited the leptin-induced stemness maintenance of OCSCs and tumorigenicity. Our findings reveal a crucial mechanism for leptin-mediated stemness maintenance and indicate that targeting c-Jun or the identified positive feedback loop has translational potential for ovarian cancer patients.

Enhanced Expression of TRIM46 in Ovarian Cancer Cells Induced by Tumor-Associated Macrophages Promotes Invasion via the Wnt/β-Catenin Pathway

Metastasis presents significant challenges in ovarian cancer treatment. Tumor-associated macrophages (TAMs) within the tumor microenvironment (TME) facilitate metastasis through epithelial-mesenchymal transition, yet the molecular underlying mechanisms are not fully understood. Here, we identified that tripartite motif-containing 46 (TRIM46) is significantly upregulated in ovarian cancer cells treated with a conditioned medium derived from macrophages stimulated by ovarian cancer cells (OC-MQs). Furthermore, TRIM46 was highly expressed in late-stage ovarian cancer patients and was associated with poor prognosis. Silencing of TRIM46 suppressed cancer cell invasion stimulated by OC-MQ and mesenchymal marker expression without affecting cell viability. Gene set enrichment analysis showed that the Wnt/β-catenin pathway is enriched in the high-TRIM46 expression group. Importantly, the inhibition of TRIM46-mediated β-catenin nuclear translocation and ovarian cancer cell invasion was reversed by CHIR99021, a Wnt/β-catenin activator. Additionally, C-X-C motif chemokine ligand 8 (CXCL8) was identified as being highly expressed in peritoneal MQs from the ascites of ovarian cancer patients and was positively correlated with C-X-C chemokine receptor 1/2 (CXCR1/2) expression in tumor cells. Notably, pre-treatment with reparixin, a CXCR1/2 inhibitor, blocked OC-MQ-induced TRIM46 expression and cell invasion. These results suggest that CXCL8 derived from TAMs promotes human ovarian cancer cell invasion via the Wnt/β-catenin pathway by upregulating TRIM46.

Campylobacter jejuni-derived cytolethal distending toxin promotes colorectal cancer metastasis

Various forms of solid tumors harbor intracellular bacteria, but the physiological consequences of these microorganisms are poorly understood. We show that Campylobacter is significantly enriched in primary colorectal cancer (CRC) lesions from patients with metastasis. Campylobacter jejuni-derived cytolethal distending toxin (CDT) promotes CRC metastasis through JAK2-STAT3-MMP9 signaling in liver or pulmonary metastatic mice models, as confirmed in C. jejuni-infected human colonic tissue and CDT-treated colonic tumoroids from patients. Genetic deletion of cdtB (ΔcdtB) or purified CdtB protein demonstrates that the genotoxin is essential for C. jejuni's pro-metastatic property. In C.-jejuni-colonized mice, increased translocation of CDT-producing C. jejuni to extraintestinal implanted tumors potentially leads to accelerated metastasis of these tumors. Overall, these findings demonstrate that an intratumor-bacteria-derived genotoxin accelerates tumor metastasis, potentially opening a new diagnostic and therapeutic avenue for cancer management.

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.

Paracrine Ovarian Cancer Cell-Derived CSF1 Signaling Regulates Macrophage Migration Dynamics in a 3D Microfluidic Model that Recapitulates In Vivo Infiltration Patterns in Patient-Derived Xenografts

A high density of macrophages in the ovarian cancer microenvironment is associated with disease progression and poor outcomes. Understanding cancer-macrophage interaction mechanisms that establish this pro-tumorigenic microenvironment is critical for developing macrophage-targeted therapies. Here, 3D microfluidic assays and patient-derived xenografts are utilized to define the role of cancer-derived colony stimulating factor 1 (CSF1) on macrophage infiltration dynamics toward ovarian cancer cells. It is demonstrated that multiple ovarian cancer models promote the infiltration of macrophages into a 3D extracellular matrix in vitro in a cell density-dependent manner. Macrophages exhibit directional migration and increased migration speed under both direct interactions with cancer cells embedded within the matrix and paracrine crosstalk with cancer cells seeded in an independent microchannel. It is also found that platinum-based chemotherapy increases macrophage recruitment and the levels of cancer cell-derived CSF1. Targeting CSF1 signaling under baseline or chemotherapy-treatment conditions reduces the number of infiltrated macrophages. It is further shown that results obtained with the 3D microfluidic model reflect the recruitment profiles of macrophages in patient-derived xenografts in vivo. These findings highlight the role of CSF1 signaling in establishing macrophage-rich ovarian cancer microenvironments, as well as the utility of microfluidic models in recapitulating 3D tumor ecosystems and dissecting cancer-macrophage signaling.

Design and development of in-vitro co-culture device for studying cellular crosstalk in varied tissue microenvironment

Despite of being in different microenvironment, breast cancer cells influence the bone cells and persuade cancer metastasis from breast to bone. Multiple co-culture approaches have been explored to study paracrine signaling between these cells and to study the progression of cancer. However, lack of native tissue microenvironment remains a major bottleneck in existing co-culture technologies. Therefore, in the present study, a tumorigenic and an osteogenic microenvironment have been sutured together to create a multi-cellular environment and has been appraised to study cancer progression in bone tissue. The PCL-polystyrene and PCL-collagen fibrous scaffolds were characterized for tumorigenic and osteogenic potential induction on MDA-MB-231 and MC3T3-E1 cells respectively. Diffusion ability of crystal violet, glucose, and bovine serum albumin across the membrane were used to access the potential paracrine interaction facilitated by device. While in co-cultured condition, MDA-MB-231 cells showed EMT phenotype along with secretion of TNFα and PTHrP which lower down the expression of osteogenic markers including alkaline phosphatase, RUNX2, Osteocalcin and Osteoprotegerin. The cancer progression in bone microenvironment demonstrated the role and necessity of creating multiple tissue microenvironment and its contribution in studying multicellular disease progression and therapeutics.

Bridging systems biology and tissue engineering: Unleashing the full potential of complex 3D in vitro tissue models of disease

Rapid advances in tissue engineering have resulted in more complex and physiologically relevant 3D in vitro tissue models with applications in fundamental biology and therapeutic development. However, the complexity provided by these models is often not leveraged fully due to the reductionist methods used to analyze them. Computational and mathematical models developed in the field of systems biology can address this issue. Yet, traditional systems biology has been mostly applied to simpler in vitro models with little physiological relevance and limited cellular complexity. Therefore, integrating these two inherently interdisciplinary fields can result in new insights and move both disciplines forward. In this review, we provide a systematic overview of how systems biology has been integrated with 3D in vitro tissue models and discuss key application areas where the synergies between both fields have led to important advances with potential translational impact. We then outline key directions for future research and discuss a framework for further integration between fields.

Sindbis Virus Vaccine Platform: A Promising Oncolytic Virus-Mediated Approach for Ovarian Cancer Treatment

This review article provides a comprehensive overview of a novel Sindbis virus vaccine platform as potential immunotherapy for ovarian cancer patients. Ovarian cancer is the most lethal of all gynecological malignancies. The majority of high-grade serous ovarian cancer (HGSOC) patients are diagnosed with advanced disease. Current treatment options are very aggressive and limited, resulting in tumor recurrences and 50-60% patient mortality within 5 years. The unique properties of armed oncolytic Sindbis virus vectors (SV) in vivo have garnered significant interest in recent years to potently target and treat ovarian cancer. We discuss the molecular biology of Sindbis virus, its mechanisms of action against ovarian cancer cells, preclinical in vivo studies, and future perspectives. The potential of Sindbis virus-based therapies for ovarian cancer treatment holds great promise and warrants further investigation. Investigations using other oncolytic viruses in preclinical studies and clinical trials are also presented.

Friend and foe: the regulation network of ascites components in ovarian cancer progression

The tumor microenvironment (TME) and its complex role in cancer progression have been hotspots of cancer research in recent years. Ascites, which occurs frequently in patients with ovarian cancer especially in advanced stages, represents a unique TME. Malignant ascites contains abundant cellular and acellular components that play important roles in tumorigenesis, growth, metastasis, and chemoresistance of ovarian cancer through complex molecular mechanisms and signaling pathways. As a valuable liquid biopsy sample, ascites fluid is also of great significance for the prognostic analysis of ovarian cancer. The components of ovarian cancer ascites are generally considered to comprise tumor-promoting factors; however, in recent years studies have found that ascites also contains tumor-suppressing factors, raising new perspectives on interactions between ascites and tumors. Malignant ascites directly constitutes the ovarian cancer microenvironment, therefore, the study of its components will aid in the development of new therapeutic strategies. This article reviews the current research on tumor-promoting and tumor-suppressing factors and molecular mechanisms of their actions in ovarian cancer-derived ascites and therapeutic strategies targeting ascites, which may provide references for the development of novel therapeutic targets for ovarian cancer in the future.

Matrix Metalloproteinase 9 Induced in Esophageal Squamous Cell Carcinoma Cells via Close Contact with Tumor-Associated Macrophages Contributes to Cancer Progression and Poor Prognosis

Tumor-associated macrophages (TAMs) contribute to disease progression in various cancers, including esophageal squamous cell carcinoma (ESCC). We have previously used an indirect co-culture system between ESCC cell lines and macrophages to analyze their interactions. Recently, we established a direct co-culture system to closely simulate actual ESCC cell-TAM contact. We found that matrix metalloproteinase 9 (MMP9) was induced in ESCC cells by direct co-culture with TAMs, not by indirect co-culture. MMP9 was associated with ESCC cell migration and invasion, and its expression was controlled by the Stat3 signaling pathway in vitro. Immunohistochemical analyses revealed that MMP9 expression in cancer cells at the invasive front ("cancer cell MMP9") was related to high infiltration of CD204 positive M2-like TAMs (p < 0.001) and was associated with worse overall and disease-free survival of patients (p = 0.036 and p = 0.038, respectively). Furthermore, cancer cell MMP9 was an independent prognostic factor for disease-free survival. Notably, MMP9 expression in cancer stroma was not associated with any clinicopathological factors or patient prognoses. Our results suggest that close interaction with TAMs infiltrating in cancer stroma or cancer nests induces MMP9 expression in ESCC cells, equipping them with more malignant features.

Extracellular Matrix in High-Grade Serous Ovarian Cancer: Advances in Understanding of Carcinogenesis and Cancer Biology

High-grade serous ovarian cancer (HGSOC) is notoriously known as the "silent killer" of post-menopausal women as it has an insidious progression and is the deadliest gynaecological cancer. Although a dual origin of HGSOC is now widely accepted, there is growing evidence that most cases of HGSOC originate from the fallopian tube epithelium. In this review, we will address the fallopian tube origin and involvement of the extracellular matrix (ECM) in HGSOC development. There is limited research on the role of ECM at the earliest stages of HGSOC carcinogenesis. Here we aim to synthesise current understanding on the contribution of ECM to each stage of HGSOC development and progression, beginning at serous tubal intraepithelial carcinoma (STIC) precursor lesions and proceeding across key events including dissemination of tumourigenic fallopian tube epithelial cells to the ovary, survival of these cells in peritoneal fluid as multicellular aggregates, and colonisation of the ovary. Likewise, as part of the metastatic series of events, serous ovarian cancer cells survive travel in peritoneal fluid, attach to, migrate across the mesothelium and invade into the sub-mesothelial matrix of secondary sites in the peritoneal cavity. Halting cancer at the pre-metastatic stage and finding ways to stop the dissemination of ovarian cancer cells from the primary site is critical for improving patient survival. The development of drug resistance also contributes to poor survival statistics in HGSOC. In this review, we provide an update on the involvement of the ECM in metastasis and drug resistance in HGSOC. Interplay between different cell-types, growth factor gradients as well as evolving ECM composition and organisation, creates microenvironment conditions that promote metastatic progression and drug resistance of ovarian cancer cells. By understanding ECM involvement in the carcinogenesis and chemoresistance of HGSOC, this may prompt ideas for further research for developing new early diagnostic tests and therapeutic strategies for HGSOC with the end goal of improving patient health outcomes.

A Subset of Secreted Proteins in Ascites Can Predict Platinum-Free Interval in Ovarian Cancer

The time between the last cycle of chemotherapy and recurrence, the platinum-free interval (PFI), predicts overall survival in high-grade serous ovarian cancer (HGSOC). To identify secreted proteins associated with a shorter PFI, we utilized machine learning to predict the PFI from ascites composition. Ascites from stage III/IV HGSOC patients treated with neoadjuvant chemotherapy (NACT) or primary debulking surgery (PDS) were screened for secreted proteins and Lasso regression models were built to predict the PFI. Through regularization techniques, the number of analytes used in each model was reduced; to minimize overfitting, we utilized an analysis of model robustness. This resulted in models with 26 analytes and a root-mean-square error (RMSE) of 19 days for the NACT cohort and 16 analytes and an RMSE of 7 days for the PDS cohort. High concentrations of MMP-2 and EMMPRIN correlated with a shorter PFI in the NACT patients, whereas high concentrations of uPA Urokinase and MMP-3 correlated with a shorter PFI in PDS patients. Our results suggest that the analysis of ascites may be useful for outcome prediction and identified factors in the tumor microenvironment that may lead to worse outcomes. Our approach to tuning for model stability, rather than only model accuracy, may be applicable to other biomarker discovery tasks.

The role of exosomal miR-181b in the crosstalk between NSCLC cells and tumor-associated macrophages

BACKGROUND

It has been reported that tumor-associated macrophages (TAMs) participate in modulating the progression of cancer in the tumor microenvironment. However, the crosstalk between TAMs and non-small cell lung cancer (NSCLC) is still unclear.

OBJECTIVE

We investigated whether NSCLC-derived exosomes could affect TAMs, which feedback modulated progression of NSCLC.

METHODS

MiR-181b expression was measured by RT-PCR. Human THP-1 monocyte was differentiated into macrophages with phorbol myristate acetate, which were further identified by transmission electron microscopy and western blot. Macrophage M1 and M2 polarizations were detected by flow cytometry, RT-PCR and western blot. Proliferation, migration, and invasion of NSCLC cells treated with conditioned mediums were detected by EdU and Transwell assays.

RESULTS

We demonstrated that miR-181b was up-regulated in exosomes derived from NSCLC patients' serum and NSCLC cells. MiR-181b could be transferred to macrophages via exosomes in the co-culture system of macrophages and NSCLC cells, which promoted macrophage M2 polarization. Further examinations revealed that exosomes derived from NSCLC cells could enhanced macrophage M2 polarizations by regulating miR-181b/JAK2/STAT3 axis, and silencing miR-181b in NSCLC cells and JAK2 inhibitor used in macrophages could reverse the effects. Importantly, the conditioned medium of macrophages treated with NSCLC cell-derived exosomes could promote NSCLC cell proliferation, migration, and invasion. Silencing miR-181b in NSCLC cells and JAK2 inhibitor used in macrophages could block the effects.

CONCLUSIONS

All of these results indicated that exosomal miR-181b participated in the crosstalk between NSCLC cells and TAMs, providing potential therapeutic targets for NSCLC.

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.

Macrophages in ovarian cancer and their interactions with monoclonal antibody therapies

The unmet clinical need for effective treatments in ovarian cancer has yet to be addressed using monoclonal antibodies (mAbs), which have largely failed to overcome tumour-associated immunosuppression, restrict cancer growth, and significantly improve survival. In recent years, experimental mAb design has moved away from solely targeting ovarian tumours and instead sought to modulate the wider tumour microenvironment (TME). Tumour-associated macrophages (TAMs) may represent an attractive therapeutic target for mAbs in ovarian cancer due to their high abundance and close proximity to tumour cells and their active involvement in facilitating several pro-tumoural processes. Moreover, the expression of several antibody crystallisable fragment (Fc) receptors and broad phenotypic plasticity of TAMs provide opportunities to modulate TAM polarisation using mAbs to promote anti-tumoural phenotypes. In this review, we discuss the role of TAMs in ovarian cancer TME and the emerging strategies to target the contributions of these cells in tumour progression through the rationale design of mAbs.

Molecular insights of metastasis and cancer progression derived using 3D cancer spheroid co-culture in vitro platform

The multistep metastasis process is carried out by the combinatorial effect of the stromal cells and the cancerous cells and plays vital role in the cancer progression. The scaffold/physical cues aided 3D cancer spheroid imitates the spatiotemporal organization and physiological properties of the tumor. Understanding the role of the key players in different stages of metastasis, the molecular cross-talk between the stromal cells and the cancer cells contributing in the advancement of the metastasis through 3D cancer spheroid co-culture in vitro platform is the center of discussion in the present review. This state-of-art in vitro platform utilized to study the cancer cell host defence and the role of exosomes in the cross talk leading to cancer progression has been critically examined here. 3D cancer spheroid co-culture technique is the promising next-generation in vitro approach for exploring potent treatments and personalized medicines to combat cancer metastasis leading to cancer progression.

Interleukin-17 activates JAK2/STAT3, PI3K/Akt and nuclear factor-κB signaling pathway to promote the tumorigenesis of cervical cancer

Interleukin (IL)-17 has been regarded as a significant factor in inflammation. In addition, IL-17 is known to be involved in the progression of cancers; however, the function of IL-17 in cervical cancer remains unclear. In the present study, cell viability was detected by Cell Counting Kit-8 assay. Quantitative PCR and western blotting were performed to detect gene and protein expression levels, respectively, in cancer cells or tissues. Ki-67 staining was used to evaluate cell proliferation. Wound-healing assay was used to detect cell migration. Moreover, Transwell assay was performed to investigate the invasion of cervical cancer cells. The results revealed that IL-17 significantly promoted the proliferation of cervical cancer cells. Additionally, IL-17 notably enhanced the migration and invasion of cervical cancer cells in vitro. IL-17 promoted the progression of cervical cancer via the activation of JAK2/STAT3 and PI3K/Akt/NF-κB signaling. In conclusion, IL-17 was a key regulator during the progression of cervical cancer through the JAK2/STAT3 and PI3K/Akt/nuclear factor-κB signaling pathway, which may serve as a novel target for the treatment of cervical cancer.

Cyy260, a novel small molecule inhibitor, suppresses non-small cell lung cancer cell growth via JAK2/STAT3 pathway

Non-small cell lung cancer (NSCLC) is a malignant tumor that accounts for the most new cancer cases and cancer-related deaths worldwide, and the proliferation and metastasis of NSCLC are the main reasons for treatment failure and patient death. Traditional chemotherapeutic drugs have low selectivity, which can kill cancer cells and cause damage to normal cells at the same time. Therefore, it is particularly important to study therapies that target cancer cells and to find low-toxicity, high-efficiency anticancer drugs. Cyy260 is a novel small molecule inhibitor that we synthesized for the first time. Here, we investigated the in vitro and in vivo antitumor activities of Cyy260 and explored the underlying mechanisms in NSCLC. Cyy260 had a concentration- and time-dependent inhibitory effect on NSCLC cells, but it was less toxic to normal cells. Cyy260 regulated apoptosis through intracellular and extracellular apoptotic pathways. In addition, Cyy260 could also induce cell cycle arrest, thereby inhibiting cell proliferation. Further analysis of molecular mechanisms showed that the JAK2/STAT3 signaling pathway was involved in the antitumor effect mediated by Cyy260. Analysis of subcutaneously transplanted tumors in mice showed that Cyy260 suppressed tumor growth in vivo. Our results proved that Cyy260 is a novel inhibitor of the JAK2/STAT3 pathway thus may have potential in therapy of NSCLC and other cancers.

Topological defects in the mesothelium suppress ovarian cancer cell clearance

We investigated an in vitro model for mesothelial clearance, wherein ovarian cancer cells invade into a layer of mesothelial cells, resulting in mesothelial retraction combined with cancer cell disaggregation and spreading. Prior to the addition of tumor cells, the mesothelial cells had an elongated morphology, causing them to align with their neighbors into well-ordered domains. Flaws in this alignment, which occur at topological defects, have been associated with altered cell density, motion, and forces. Here, we identified topological defects in the mesothelial layer and showed how they affected local cell density by producing a net flow of cells inward or outward, depending on the defect type. At locations of net inward flow, mesothelial clearance was impeded. Hence, the collective behavior of the mesothelial cells, as governed by the topological defects, affected tumor cell clearance and spreading. Importantly, our findings were consistent across multiple ovarian cancer cell types, suggesting a new physical mechanism that could impact ovarian cancer metastasis.

CC Chemokine Ligand 7 Derived from Cancer-Stimulated Macrophages Promotes Ovarian Cancer Cell Invasion

In the tumor microenvironment, macrophages have been suggested to be stimulated by tumor cells, becoming tumor-associated macrophages that promote cancer development and progression. We examined the effect of these macrophages on human ovarian cancer cell invasion and found that conditioned medium of macrophages stimulated by ovarian cancer cells (OC-MQs) significantly increased cell invasion. CC chemokine ligand 7 (CCL7) expression and production were significantly higher in OC-MQs than in the control macrophages. Peritoneal macrophages from patients with ovarian cancer showed higher CCL7 expression levels than those from healthy controls. Inhibition of CCL7 using siRNA and neutralizing antibodies reduced the OC-MQ-CM-induced ovarian cancer cell invasion. CC chemokine receptor 3 (CCR3) was highly expressed in human ovarian cancer cells, and a specific inhibitor of this receptor reduced the OC-MQ-CM-induced invasion. Specific signaling and transcription factors were associated with enhanced CCL7 expression in OC-MQs. CCL7-induced invasion required the expression of matrix metalloproteinase 9 via activation of extracellular signal-related kinase signaling in human ovarian cancer cells. These data suggest that tumor-associated macrophages can affect human ovarian cancer metastasis via the CCL7/CCR3 axis.

KCNQ1OT1 lncRNA affects the proliferation, apoptosis, and chemoresistance of small cell lung cancer cells via the JAK2/STAT3 axis

Background

Small cell lung cancer (SCLC) is a devastating and aggressive neuroendocrine carcinoma characterized by high cellular proliferation and early metastatic spread. Numerous studies have demonstrated that long noncoding RNAs (lncRNAs) can regulate tumor generation and development, including in SCLC. The current study aimed to assess the effect of the lncRNA, KCNQ1OT1, on the proliferation, apoptosis, and chemoresistance of SCLC and the potential underlying molecular mechanism.

Methods

Matched chemo-resistant and sensitive cells were applied to RNA isolation and followed by expression profiling by microarray analysis and subsequent quantitative polymerase chain reaction (qPCR) validation. Cell viability and apoptosis were determined by Cell Counting Kit-8 and flow cytometry to examine the chemoresistance and apoptosis of KCNQ1OT1 knockdown with lentivirus-mediated RNA interference. Furthermore, cell proliferation was studied by colony formation, and invasion and migration were tested by Transwell cell invasion and wound-healing assays, respectively. A tumor xenograft model was established to determine the role of KCNQ1OT1 in tumor growth and chemoresistance in response to KCNQ1OT1 knockdown in vivo. Western blot analysis, qPCR, and immunohistochemistry were used to detect the levels of messenger RNA (mRNA) Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway-related markers.

Results

Higher expression of KCNQ1OT1 was detected in SCLC chemo-resistant verso chemo-sensitive cells. Knockdown of KCNQ1OT1 inhibited SCLC cell viability and cloning ability, hindered cell migration and invasion, induced apoptosis in vitro, and suppressed tumor growth and chemoresistance in vivo, by activating the JAK2/STAT3 signaling pathway.

Conclusions

This is the first study to indicate that lncRNA KCNQ1OT1 promotes cell proliferation and invasion, and prevents apoptosis of SCLC by activating the JAK2/STAT3 pathway.

Extracellular Matrix: A Treasure Trove in Ovarian Cancer Dissemination and Chemotherapeutic Resistance

Late presentation and resistance to chemotherapeutic agents make a deadly combination for ovarian cancer patients. The treatment of these patients is thus challenging. This study explores the possible molecular mechanisms by which tumor cells interact with the extracellular matrix (ECM) constituents, forming metastatic implants and enhancing patients' sensitivity to drugs. For the literature review, PubMed was used as a database. The standard search was done using keywords "collagen, ovarian cancer, extracellular matrix, drug resistance" in different combinations, which finally yielded 32 studies meeting the inclusion/exclusion criteria. The studies included were published in the English language in the past seven years.

After analyzing, we found all of them to be histopathological studies. Nine studies also used murine cell lines besides human cell lines and tissue samples from ovarian cancer patients. One study has a retrospective analysis done. Eight studies demonstrate the role of hypoxia and matrix remodeling enzymes in ovarian cancer dissemination. Genetics playing a crucial role in cancer metastasis is demonstrated in eight studies. Ten studies included shows receptors, enzymes, and spheroid organization in disease progression. Six studies address chemotherapeutic resistance. Intraperitoneal dissemination of ovarian cancer and the development of chemotherapeutic resistance depends on certain molecular interactions, and they can be targeted to improve patients' overall survival.

Macrophages: an indispensable piece of ovarian health

Macrophages are the most abundant immune cells in the ovary. In addition to their roles in the innate immune system, these heterogeneous tissue-resident cells are responsive to tissue-derived signals, adapt to their local tissue environment, and specialize in unique functions to maintain tissue homeostasis. Research in the past decades has established a strong link between macrophages and various aspects of ovarian physiology, indicating a pivotal role of macrophages in ovarian health. However, unlike other intensively studied organs, the knowledge of ovarian macrophages dates back to the time when the heterogeneity of ontogeny, phenotype, and function of macrophages was not fully understood. In this review, we discuss the evolving understanding of the biology of ovarian tissue-resident macrophages, highlight their regulatory roles in normal ovarian functions, review the association between certain ovarian pathologies and disturbed macrophage homeostasis, and finally, discuss the technologies that are essential for addressing key questions in the field.

Biomaterial strategies to replicate gynecological tissue

Properties of native tissue can inspire biomimetic in vitro models of gynecological disease.

Ovarian cancer cells direct monocyte differentiation through a non-canonical pathway

BACKGROUND

Alternatively-activated macrophages (AAMs), an anti-inflammatory macrophage subpopulation, have been implicated in the progression of high grade serous ovarian carcinoma (HGSOC). Increased levels of AAMs are correlated with poor HGSOC survival rates, and AAMs increase the attachment and spread of HGSOC cells in vitro. However, the mechanism by which monocytes in the HGSOC tumor microenvironment are differentiated and polarized to AAMs remains unknown.

METHODS

Using an in vitro co-culture device, we cultured naïve, primary human monocytes with a panel of five HGSOC cell lines over the course of 7 days. An empirical Bayesian statistical method, EBSeq, was used to couple RNA-seq with observed monocyte-derived cell phenotype to explore which HGSOC-derived soluble factors supported differentiation to CD68+ macrophages and subsequent polarization towards CD163+ AAMs. Pathways of interest were interrogated using small molecule inhibitors, neutralizing antibodies, and CRISPR knockout cell lines.

RESULTS

HGSOC cell lines displayed a wide range of abilities to generate AAMs from naïve monocytes. Much of this variation appeared to result from differential ability to generate CD68+ macrophages, as most CD68+ cells were also CD163+. Differences in tumor cell potential to generate macrophages was not due to a MCSF-dependent mechanism, nor variance in established pro-AAM factors. TGFα was implicated as a potential signaling molecule produced by tumor cells that could induce macrophage differentiation, which was validated using a CRISPR knockout of TGFA in the OVCAR5 cell line.

CONCLUSIONS

HGSOC production of TGFα drives monocytes to differentiate into macrophages, representing a central arm of the mechanism by which AAMs are generated in the tumor microenvironment.

Ovarian Cells Have Increased Proliferation in Response to Heparin-Binding Epidermal Growth Factor as Collagen Density Increases

It is well known that during ovarian cancer progression, the omentum transforms from a thin lacy organ to a thick tougher tissue. However, the mechanisms regulating this transformation and the implications of the altered microenvironment on ovarian cancer progression remain unclear. To address these questions, the global and local concentrations of collagen I were determined for normal and metastatic human omentum. Collagen I was increased 5.3-fold in omenta from ovarian cancer patients and localized to areas of activated fibroblasts rather than regions with a high density of cancer cells. Transforming growth factor beta 1 (TGFβ1) was detected in ascites from ovarian cancer patients (4 ng/mL), suggesting a potential role for TGFβ1 in the observed increase in collagen. Treatment with TGFβ1 induced fibroblast activation, proliferation, and collagen deposition in mouse omental explants and an in vitro model with human omental fibroblasts. Finally, the impact of increased collagen I on ovarian cancer cells was determined by examining proliferation on collagen I gels formulated to mimic normal and cancerous omenta. While collagen density alone had no impact on proliferation, a synergistic effect was observed with collagen density and heparin-binding epidermal growth factor treatment. These results suggest that TGFβ1 induces collagen deposition from the resident fibroblasts in the omentum and that this altered microenvironment impacts cancer cell response to growth factors found in ascites. Impact statement Using quantitative analysis of patient samples, in vitro models of the metastatic ovarian cancer microenvironment were designed with pathologically relevant collagen densities and growth factor concentrations. Studies in these models support a mechanism where transforming growth factor β1 in the ascites fluid induces omental fibroblast proliferation, activation, and deposition of collagen I, which then impacts tumor cell proliferation in response to additional ascites growth factors such as heparin-binding epidermal growth factor. This approach can be used to dissect mechanisms involved in microenvironmental modeling in multiple disease applications.

Tumor associated macrophages in the molecular pathogenesis of ovarian cancer

The tumor microenvironment is a critical factor that enhances cancer progression, drug resistance, and failure of therapeutic approaches. Several cellular and non-cellular factors are involved in cancer promotion. Among the several cell populations in the tumor microenvironment, macrophages, as one of the most abundant innate immune cells within the tumor milieu, have attracted extensive attention among several researchers because of their critical role in innate pathophysiology of multiple disorders, as well as ovarian cancer. High plasticity and consequent high ability to adapt to environmental alternations by adjusting their cellular metabolism and immunological phenotype is the notable characteristic of macrophages. Therefore, the critical function of tumor-associated macrophages in ovarian cancer is highlighted in the growing body of recent studies. In this article, we will comprehensively focus on significant impacts of the macrophages on ovarian cancer progression, by discussing the role of macrophages as one of the fundamental immune cells present in tumor milieu, in metabolic reprogramming of transformed cells, and involvement of these cells in the ovarian cancer initiation, progression, invasion, and angiogenesis. Moreover, we will summarise recent studies evaluating the effects of targeting macrophages in ovarian cancer.

The Many Microenvironments of Ovarian Cancer

High-grade serous ovarian cancer (HGSOC) is the most common and deadly subtype of ovarian cancer as it is commonly diagnosed after substantial metastasis has already occurred. The past two decades have been an active era in HGSOC research, with new information on the origin and genomic signature of the tumor cell. Additionally, studies have begun to characterize changes in the HGSOC microenvironment and examine the impact of these changes on tumor progression and response to therapies. While this knowledge may provide valuable insight into better prognosis and treatments for HGSOCs, its collection, synthesis, and application are complicated by the number of unique microenvironments in the disease-the initiating site (fallopian tube), first metastasis (ovary), distal metastases (peritoneum), and recurrent/platinum-resistant setting. Here, we review the state of our understanding of these diverse sites and highlight remaining questions.

CAGE-miR-140-5p-Wnt1 Axis Regulates Autophagic Flux, Tumorigenic Potential of Mouse Colon Cancer Cells and Cellular Interactions Mediated by Exosomes

Although the cancer/testis antigen CAGE has been implicated in tumorigenesis, the molecular mechanisms of CAGE-promoted tumorigenesis remain largely unknown. CT26^Flag−CAGE cells, CT26 (mouse colon cancer cells) cells stably expressing CAGE, were established to investigate CAGE-promoted tumorigenesis. Down-regulation of CAGE led to decreased autophagic flux in CT26^Flag−CAGE cells. CAGE interacted with Beclin1, a mediator of autophagy. The CT26^Flag−CAGE cells showed enhanced autophagosome formation and displayed greater tumor spheroid-forming potential than CT26 cells. MicroRNA array analysis revealed that CAGE decreased the expression of various microRNAs, including miR-140-5p, in CT26 cells. CAGE was shown to bind to the promoter sequences of miR-140-5p. MiR-140-5p inhibition increased the tumorigenic potential of and autophagic flux in CT26 cells. A miR-140-5p mimic exerted negative effects on the tumorigenic potential of CT26^Flag−CAGE cells and autophagic flux in CT26^Flag−CAGE cells. MiR-140-5p was predicted to bind to the 3′-UTR of Wnt1. CT26^Flag−CAGE cells showed higher expression of Wnt1 than CT26 cells. Down-regulation of Wnt1 decreased autophagic flux. Luciferase activity assays showed the direct regulation of wnt1 by miR-140-5p. Tumor tissue derived from the CT26^Flag−CAGE cells revealed higher expressions of factors associated with activated mast cells and tumor-associated macrophages than tumor tissue derived from CT26 cells. Culture medium from the CT26^Flag−CAGE cells increased autophagic flux in CT26 cells, mast cells and macrophages. Culture medium from the CT26^Flag−CAGE cells increased CD163 and autophagic flux in CT26 cells, mast cells, and macrophages in a Wnt1-dependent manner. Exosomes from CT26^Flag−CAGE cells increased autophagc flux in CT26 cells, mast cells, and macrophages. Exosomes from CT26^Flag−CAGE cells increased the tumorigenic potential of CT26 cells. Wnt1 was shown to be present within the exosomes. Recombinant Wnt1 protein increased autophagic flux in CT26, mast cells, and macrophages. Recombinant wnt1 protein mediated interactions between the CT26 cells, mast cells, and macrophages. Our results showed novel roles for the CAGE-miR-140-5p-Wnt1 axis in autophagic flux and cellular interactions mediated by exosomes.

Tumor-Associated Macrophages (TAMs): A Critical Activator In Ovarian Cancer Metastasis

Tumor-associated macrophages (TAMs) that appear in every stage of cancer progression are usually tumor-promoting cells and are present abundantly in the tumor-associated microenvironment. In ovarian cancer, the overall and intratumoral M1/M2 ratio is a relatively efficient TAM parameter for predicting the prognosis of patients, especially for serous tissue type cancer. TAMs exhibit immunological checkpoint modulators, such as the B7 family and programmed death-ligand 1 (PD-L1), and play a key role in the development, metastasis and invasion of ovarian cancer, but the underlying mechanism is barely understood. Ovarian cancer is a severe gynecological malignancy with high mortality. Ovarian cancer-associated death can primarily be attributed to cancer metastasis. The majority of patients are diagnosed with wide dissemination in the peritoneum and omentum, limiting the effectiveness of surgery and chemotherapy. In addition, unlike other well-documented cancers, metastasis through vasculature is not a usual dissemination pathway in ovarian cancer. This review sheds light on TAMs and the main process and mechanism of ovarian cancer metastasis.

The Role of Cancer Stem Cells and Mechanical Forces in Ovarian Cancer Metastasis

Ovarian cancer is an extremely lethal gynecologic disease; with the high-grade serous subtype predominantly associated with poor survival rates. Lack of early diagnostic biomarkers and prevalence of post-treatment recurrence, present substantial challenges in treating ovarian cancers. These cancers are also characterized by a high degree of heterogeneity and protracted metastasis, further complicating treatment. Within the ovarian tumor microenvironment, cancer stem-like cells and mechanical stimuli are two underappreciated key elements that play a crucial role in facilitating these outcomes. In this review article, we highlight their roles in modulating ovarian cancer metastasis. Specifically, we outline the clinical relevance of cancer stem-like cells, and challenges associated with their identification and characterization and summarize the ways in which they modulate ovarian cancer metastasis. Further, we review the mechanical cues in the ovarian tumor microenvironment, including, tension, shear, compression and matrix stiffness, that influence (cancer stem-like cells and) metastasis in ovarian cancers. Lastly, we outline the challenges associated with probing these important modulators of ovarian cancer metastasis and provide suggestions for incorporating these cues in basic biology and translational research focused on metastasis. We conclude that future studies on ovarian cancer metastasis will benefit from the careful consideration of mechanical stimuli and cancer stem cells, ultimately allowing for the development of more effective therapies.