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

Advances in the treatment of malignant ascites in China

PURPOSE

Malignant ascites (MA) often occurs in recurrent abdominal malignant tumors, and the large amount of ascites associated with cancerous peritonitis not only leads to severe abdominal distension and breathing difficulties, but also reduces the patient's quality of life and ability to resist diseases, which usually makes it difficult to carry out anti-cancer treatment. The exploration of MA treatment methods is also a key link in MA treatment. This article is going to review the treatment of MA, to provide details for further research on the treatment of MA, and to provide some guidance for the clinical treatment of MA.

METHOD

This review analyzes various expert papers and summarizes them to obtain the paper.

RESULT

There are various treatment methods for MA, including systemic therapy and local therapy. Among them, systemic therapy includes diuretic therapy, chemotherapy, immunotherapy, targeted therapy, anti angiogenic therapy, CAR-T, and vaccine. Local therapy includes puncture surgery, peritoneal vein shunt surgery, acellular ascites infusion therapy, radioactive nuclide intraperitoneal injection therapy, tunnel catheter, and intraperitoneal hyperthermia chemotherapy. And traditional Chinese medicine treatment has also played a role in enhancing efficacy and reducing toxicity to a certain extent.

CONCLUSION

Although there has been significant progress in the treatment of MA, it is still one of the clinical difficulties. Exploring the combination or method of drugs with the best therapeutic effect and the least adverse reactions to control MA is still an urgent problem to be solved.

Defining the Role of Metastasis-Initiating Cells in Promoting Carcinogenesis in Ovarian Cancer

Ovarian cancer is the deadliest gynecological malignancy with a high prevalence of transcoelomic metastasis. Metastasis is a multi-step process and only a small percentage of cancer cells, metastasis-initiating cells (MICs), have the capacity to finally establish metastatic lesions. These MICs maintain a certain level of stemness that allows them to differentiate into other cell types with distinct transcriptomic profiles and swiftly adapt to external stresses. Furthermore, they can coordinate with the microenvironment, through reciprocal interactions, to invade and establish metastases. Therefore, identifying, characterizing, and targeting MICs is a promising strategy to counter the spread of ovarian cancer. In this review, we provided an overview of OC MICs in the context of characterization, identification through cell surface markers, and their interactions with the metastatic niche to promote metastatic colonization.

Stromal DDR2 Promotes Ovarian Cancer Metastasis through Regulation of Metabolism and Secretion of Extracellular Matrix Proteins

Ovarian cancer is the leading cause of gynecologic cancer-related deaths. The propensity for metastasis within the peritoneal cavity is a driving factor for the poor outcomes associated with this disease, but there is currently no effective therapy targeting metastasis. In this study, we investigate the contribution of stromal cells to ovarian cancer metastasis and identify normal stromal cell expression of the collagen receptor, discoidin domain receptor 2 (DDR2), that acts to facilitate ovarian cancer metastasis. In vivo, global genetic inactivation of Ddr2 impairs the ability of Ddr2-expressing syngeneic ovarian cancer cells to spread throughout the peritoneal cavity. Specifically, DDR2 expression in mesothelial cells lining the peritoneal cavity facilitates tumor cell attachment and clearance. Subsequently, omentum fibroblast expression of DDR2 promotes tumor cell invasion. Mechanistically, we find DDR2-expressing fibroblasts are more energetically active, such that DDR2 regulates glycolysis through AKT/SNAI1 leading to suppressed fructose-1,6-bisphosphatase and increased hexokinase activity, a key glycolytic enzyme. Upon inhibition of DDR2, we find decreased protein synthesis and secretion. Consequently, when DDR2 is inhibited, there is reduction in secreted extracellular matrix proteins important for metastasis. Specifically, we find that fibroblast DDR2 inhibition leads to decreased secretion of the collagen crosslinker, LOXL2. Adding back LOXL2 to DDR2 deficient fibroblasts rescues the ability of tumor cells to invade. Overall, our results suggest that stromal cell expression of DDR2 is an important mediator of ovarian cancer metastasis.

IMPLICATIONS

DDR2 is highly expressed by stromal cells in ovarian cancer that can mediate metastasis and is a potential therapeutic target in ovarian cancer.

Profiling ovarian cancer tumor and microenvironment during disease progression for cell-based immunotherapy design

Ovarian cancer (OC) is highly lethal due to late detection and frequent recurrence. Initial treatments, comprising surgery and chemotherapy, lead to disease remission but are invariably associated with subsequent relapse. The identification of novel therapies and an improved understanding of the molecular and cellular characteristics of OC are urgently needed. Here, we conducted a comprehensive analysis of primary tumor cells and their microenvironment from 16 chemonaive and 10 recurrent OC patient samples. Profiling OC tumor biomarkers allowed for the identification of potential molecular targets for developing immunotherapies, while profiling the microenvironment yielded insights into its cellular composition and property changes between chemonaive and recurrent samples. Notably, we identified CD1d as a biomarker of the OC microenvironment and demonstrated its targeting by invariant natural killer T (iNKT) cells. Overall, our study presents a comprehensive immuno-profiling of OC tumor and microenvironment during disease progression, guiding the development of immunotherapies for OC treatment, especially for recurrent disease.

The interaction of β-arrestin1 with talin1 driven by endothelin A receptor as a feature of α5β1 integrin activation in high-grade serous ovarian cancer

Dissemination of high-grade serous ovarian cancer (HG-SOC) in the omentum and intercalation into a mesothelial cell (MC) monolayer depends on functional α5β1 integrin (Intα5β1) activity. Although the binding of Intα5β1 to fibronectin drives these processes, other molecular mechanisms linked to integrin inside-out signaling might support metastatic dissemination. Here, we report a novel interactive signaling that contributes to Intα5β1 activation and accelerates tumor cells toward invasive disease, involving the protein β-arrestin1 (β-arr1) and the activation of the endothelin A receptor (ET_AR) by endothelin-1 (ET-1). As demonstrated in primary HG-SOC cells and SOC cell lines, ET-1 increased Intβ1 and downstream FAK/paxillin activation. Mechanistically, β-arr1 directly interacts with talin1 and Intβ1, promoting talin1 phosphorylation and its recruitment to Intβ1, thus fueling integrin inside-out activation. In 3D spheroids and organotypic models mimicking the omentum, ET_AR/β-arr1-driven Intα5β1 signaling promotes the survival of cell clusters, with mesothelium-intercalation capacity and invasive behavior. The treatment with the antagonist of ET_AR, Ambrisentan (AMB), and of Intα5β1, ATN161, inhibits ET-1-driven Intα5β1 activity in vitro, and tumor cell adhesion and spreading to intraperitoneal organs and Intβ1 activity in vivo. As a prognostic factor, high EDNRA/ITGB1 expression correlates with poor HG-SOC clinical outcomes. These findings highlight a new role of ET_AR/β-arr1 operating an inside-out integrin activation to modulate the metastatic process and suggest that in the new integrin-targeting programs might be considered that ET_AR/β-arr1 regulates Intα5β1 functional pathway.

Prognostic and Predictive Role of Tumor-Infiltrating Lymphocytes (TILs) in Ovarian Cancer

In the last decade, tumor-infiltrating lymphocytes (TILs) have been recognized as clinically relevant prognostic markers for improved survival, providing the immunological basis for the development of new therapeutic strategies and showing a significant prognostic and predictive role in several malignancies, including ovarian cancer (OC). In fact, many OCs show TILs whose typology and degree of infiltration have been shown to be strongly correlated with prognosis and survival. The OC histological subtype with the higher presence of TILs is the high-grade serous carcinoma (HGSC) followed by the endometrioid subtype, whereas mucinous and clear cell OCs seem to contain a lower percentage of TILs. The abundant presence of TILs in OC suggests an immunogenic potential for this tumor. Despite the high immunogenic potential, OC has been described as a highly immunosuppressive tumor with a high expression of PD1 by TILs. Although further studies are needed to better define their role in prognostic stratification and the therapeutic implication, intraepithelial TILs represent a relevant prognostic factor to take into account in OC. In this review, we will discuss the promising role of TILs as markers which are able to reflect the anticancer immune response, describing their potential capability to predict prognosis and therapy response in OC.

Integration of Transcriptome and Epigenome to Identify and Develop Prognostic Markers for Ovarian Cancer

DNA methylation is a widely researched epigenetic modification. It is associated with the occurrence and development of cancer and has helped evaluate patients' prognoses. However, most existing DNA methylation prognosis models have not simultaneously considered the changes of the downstream transcriptome. Methods. The RNA-Sequencing data and DNA methylation omics data of ovarian cancer patients were downloaded from The Cancer Genome Atlas (TCGA) database. The Consensus Cluster Plus algorithm was used to construct the methylated molecular subtypes of the ovary. Lasso regression was employed to build a multi-gene signature. An independent data set was applied to verify the prognostic value of the signature. The Gene Set Variation Analysis (GSVA) was used to carry out the enrichment analysis of the pathways linked to the gene signature. The IMvigor 210 cohort was used to explore the predictive efficacy of the gene signature for immunotherapy response. Results. We distinguished ovarian cancer samples into two subtypes with different prognosis, based on the omics data of DNA methylation. Differentially expressed genes and enrichment analysis among subtypes indicated that DNA methylation was related to fatty acid metabolism and the extracellular matrix (ECM)-receptor. Furthermore, we constructed an 8-gene signature, which proved to be efficient and stable in predicting prognostics in ovarian cancer patients with different data sets and distinctive pathological characteristics. Finally, the 8-gene signature could predict patients' responses to immunotherapy. The polymerase chain reaction experiment was further used to verify the expression of 8 genes. Conclusion. We analyzed the prognostic value of the related genes of methylation in ovarian cancer. The 8-gene signature predicted the prognosis and immunotherapy response of ovarian cancer patients well and is expected to be valuable in clinical application.

Omentum-on-a-chip: A multicellular, vascularized microfluidic model of the human peritoneum for the study of ovarian cancer metastases

Epithelial ovarian cancer has the highest mortality rate of any gynecologic malignancy and most frequently metastasizes to the peritoneal cavity. Intraperitoneal metastases are highly associated with ascites, the pathologic accumulation of peritoneal fluid due to impaired drainage, increased peritoneal permeability, and tumor and stromal cytokine secretion. However, the relationship between ascites, vascular and mesothelial permeability, and ovarian cancer intraperitoneal metastases remains poorly understood. In this study, a vascularized in vitro model of the human peritoneal omentum and ovarian tumor microenvironment (TME) was employed to study stromal cell effects on tumor cell (TC) attachment and growth, as well as TC effects on vascular and mesothelial permeability in models of both early- and late-stage metastases. Control over the number of TCs seeded in the vascularized peritoneum revealed a critical cell density requirement for tumor growth, which was further enhanced by stromal adipocytes and endothelial cells found in the peritoneal omentum. This tumor growth resulted in both a physically-mediated decrease and cytokine-mediated increase in microvascular permeability, emphasizing the important and potentially opposing roles of tumor cells in ascites formation. This system provides a robust platform to elucidate TC-stromal cell interactions during intraperitoneal metastasis of ovarian cancer and presents the first in vitro vascularized model of the human peritoneum and ovarian cancer TME.

The Entanglement between Mitochondrial DNA and Tumor Metastasis

Simple Summary

Mitochondrial dysfunction is one of the main features of cancer cells. As genetic material in mitochondria, mitochondrial DNA (mtDNA) variations and dysregulation of mitochondria-encoded genes have been shown to correlate with survival outcomes in cancer patients. Cancer metastasis is often a major cause of treatment failure, which is a multi-step cascade process. With the development of gene sequencing and in vivo modeling technology, the role of mtDNA in cancer metastasis has been continuously explored. Our review systematically provides a summary of the multiple roles of mtDNA in cancer metastasis and presents the broad prospects for mtDNA in cancer prediction and therapy.

Abstract

Mitochondrial DNA, the genetic material in mitochondria, encodes essential oxidative phosphorylation proteins and plays an important role in mitochondrial respiration and energy transfer. With the development of genome sequencing and the emergence of novel in vivo modeling techniques, the role of mtDNA in cancer biology is gaining more attention. Abnormalities of mtDNA result in not only mitochondrial dysfunction of the the cancer cells and malignant behaviors, but regulation of the tumor microenvironment, which becomes more aggressive. Here, we review the recent progress in the regulation of cancer metastasis using mtDNA and the underlying mechanisms, which may identify opportunities for finding novel cancer prediction and therapeutic targets.

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.

Amelioration of human peritoneal mesothelial cell co-culture-evoked malignant potential of ovarian cancer cells by acacetin involves LPA release-activated RAGE-PI3K/AKT signaling

Background

Ovarian cancer is a devastating gynecological malignancy and frequently presents as an advanced carcinoma with disseminated peritoneum metastasis. Acacetin exerts anti-cancerous effects in several carcinomas. Here, we sought to investigate acacetin function in ovarian cancer malignancy triggered by peritoneal mesothelial cells.

Methods

Peritoneal mesothelial cells were treated with acacetin, and then the conditioned medium was collected to treat ovarian cancer cells. Then, cell proliferation was analyzed by MTT assay. Transwell analysis was conducted to evaluate cell invasion. Protein expression was determined by western blotting. ELISA and qRT-PCR were applied to analyze inflammatory cytokine levels. The underlying mechanism was also explored.

Results

Acacetin suppressed cell proliferation and invasion, but enhanced cell apoptosis. Furthermore, mesothelial cell-evoked malignant characteristics were inhibited when mesothelial cells were pre-treated with acacetin via restraining cell proliferation and invasion, concomitant with decreases in proliferation-related PCNA, MMP-2 and MMP-9 levels. Simultaneously, acacetin reduced mesothelial cell-induced transcripts and production of pro-inflammatory cytokine IL-6 and IL-8 in ovarian cancer cells. Mechanically, acacetin decreased lysophosphatidic acid (LPA) release from mesothelial cells, and subsequent activation of receptor for advanced glycation end-products (RAGE)-PI3K/AKT signaling in ovarian cancer cells. Notably, exogenous LPA restored the above pathway, and offset the efficacy of acacetin against mesothelial cell-evoked malignancy in ovarian cancer cells, including cell proliferation, invasion and inflammatory cytokine production.

Conclusions

Acacetin may not only engender direct inhibition of ovarian cancer cell malignancy, but also antagonize mesothelial cell-evoked malignancy by blocking LPA release-activated RAGE-PI3K/AKT signaling. Thus, these findings provide supporting evidence for a promising therapeutic agent against ovarian cancer.

Graphical Abstract

Analysis of the signal cross talk via CCL26 in the tumor microenvironment in osteosarcoma

Interaction with surrounding healthy cells plays a major role in the growth and metastasis of osteosarcoma. In this study, we hypothesized that humoral factors, which do not require direct contact with cells, are involved in the interaction between osteosarcoma and the surrounding cells. We identified the humoral factor involved in the association between tumor cells and surrounding normal cells using a co-culture model and investigated the significance of our findings. When human osteosarcoma cells (MG63) and human mesenchymal stem cells (hMSCs) were co-cultured and comprehensively analyzed for changes in each culture group, we found that the expression of chemokine (CC motif) ligand 26 (CCL26) was significantly enhanced. We also analyzed the changes in cell proliferation in co-culture, enhanced interaction with administration of recombinant CCL26 (rCCL26), reduced interaction with administration of anti-CCL26 antibodies, changes in invasive and metastatic abilities. CCL26 levels, motility, and invasive capability increased in the co-culture group and the group with added rCCL26, compared to the corresponding values in the MG63 single culture group. In the group with added CCL26 neutralizing antibodies, CCL26 level decreased in both the single and co-culture groups, and motility and invasive ability were also reduced. In a nude mice lung metastasis model, the number of lung metastases increased in the co-culture group and the group with added rCCL26, whereas the number of tumors were suppressed in the group with added neutralizing antibodies compared to those in the MG63 alone. This study identified a possible mechanism by which osteosarcoma cells altered the properties of normal cells to favorably change the microenvironment proximal to tumors and to promote distant metastasis.

A systematic CRISPR screen reveals an IL-20/IL20RA-mediated immune crosstalk to prevent the ovarian cancer metastasis

Transcoelomic spread of cancer cells across the peritoneal cavity occurs in most initially diagnosed ovarian cancer (OC) patients and accounts for most cancer-related death. However, how OC cells interact with peritoneal stromal cells to evade the immune surveillance remains largely unexplored. Here, through an in vivo genome-wide CRISPR/Cas9 screen, we identified IL20RA, which decreased dramatically in OC patients during peritoneal metastasis, as a key factor preventing the transcoelomic metastasis of OC. Reconstitution of IL20RA in highly metastatic OC cells greatly suppresses the transcoelomic metastasis. OC cells, when disseminate into the peritoneal cavity, greatly induce peritoneum mesothelial cells to express IL-20 and IL-24, which in turn activate the IL20RA downstream signaling in OC cells to produce mature IL-18, eventually resulting in the polarization of macrophages into the M1-like subtype to clear the cancer cells. Thus, we show an IL-20/IL20RA-mediated crosstalk between OC and mesothelial cells that supports a metastasis-repressing immune microenvironment.

Integrin α2β1 Represents a Prognostic and Predictive Biomarker in Primary Ovarian Cancer

Currently, the same first-line chemotherapy is administered to almost all patients suffering from primary ovarian cancer. The high recurrence rate emphasizes the need for precise drug treatment in primary ovarian cancer. Being crucial in ovarian cancer progression and chemotherapeutic resistance, integrins became promising therapeutic targets. To evaluate its prognostic and predictive value, in the present study, the expression of integrin α2β1 was analyzed immunohistochemically and correlated with the survival data and other therapy-relevant biomarkers. The significant correlation of a high α2β1-expression with the estrogen receptor alpha (ERα; p = 0.035) and epithelial growth factor receptor (EGFR; p = 0.027) was observed. In addition, high α2β1-expression was significantly associated with a low number of tumor-infiltrating immune cells (CD3 intratumoral, p = 0.017; CD3 stromal, p = 0.035; PD-1 intratumoral, p = 0.002; PD-1 stromal, p = 0.049) and the lack of PD-L1 expression (p = 0.005). In Kaplan–Meier survival analysis, patients with a high expression of integrin α2β1 revealed a significant shorter progression-free survival (PFS, p = 0.035) and platinum-free interval (PFI, p = 0.034). In the multivariate Cox regression analysis, integrin α2β1 was confirmed as an independent prognostic factor for both PFS (p = 0.021) and PFI (p = 0.020). Dual expression of integrin α2β1 and the hepatocyte growth factor receptor (HGFR; PFS/PFI, p = 0.004) and CD44v6 (PFS, p = 0.000; PFI, p = 0.001; overall survival [OS], p = 0.025) impaired survival. Integrin α2β1 was established as a prognostic and predictive marker in primary ovarian cancer with the potential to stratify patients for chemotherapy and immunotherapy, and to design new targeted treatment strategies.

MAPK Signaling Is Required for Generation of Tunneling Nanotube-Like Structures in Ovarian Cancer Cells

Simple Summary

Ovarian cancer is the 5th leading cause of cancer death in US women, due to late diagnosis. The vast majority of patients with ovarian cancer have metastatic disease at diagnosis, leading to poor survival. As the tumor cells metastasize, they are influenced by other cells they encounter. In particular, we found that macrophages induce a mechanism of communication in tumor cells called tunneling nanotubes. These tunneling nanotubes allow cells to share molecules that promote metastasis. We found that macrophages send signals to the tumor cells in order to activate oncogenic MAPKinase signaling, which is required for tunneling nanotubes to form. Our new understanding of these events will enable us to devise ways to target tunneling nanotubes and limit tumor spread.

Abstract

Ovarian cancer (OC) cells survive in the peritoneal cavity in a complex microenvironment composed of diverse cell types. The interaction between tumor cells and non-malignant cells is crucial to the success of the metastatic process. Macrophages activate pro-metastatic signaling pathways in ovarian cancer cells (OCCs), induce tumor angiogenesis, and orchestrate a tumor suppressive immune response by releasing anti-inflammatory cytokines. Understanding the interaction between immune cells and tumor cells will enhance our ability to combat tumor growth and dissemination. When co-cultured with OCCs, macrophages induce projections consistent with tunneling nanotubes (TnTs) to form between OCCs. TnTs mediate transfer of material between cells, thus promoting invasiveness, angiogenesis, proliferation, and/or therapy resistance. Macrophage induction of OCC TnTs occurs through a soluble mediator as macrophage-conditioned media potently induced TnT formation in OCCs. Additionally, EGFR-induced TnT formation in OCCs through MAPK signaling may occur. In particular, inhibition of ERK and RSK prevented EGFR-induced TnTs. TnT formation in response to macrophage-conditioned media or EGFR signaling required MAPK signaling. Collectively, these studies suggest that inhibition of ERK/RSK activity may dampen macrophage-OCC communication and be a promising therapeutic strategy.

Lipid Regulatory Proteins as Potential Therapeutic Targets for Ovarian Cancer in Obese Women

Obesity has become a recognized global epidemic that is associated with numerous comorbidities including type II diabetes, cardiovascular disease, hypertension, and cancer incidence and progression. Ovarian cancer (OvCa) has a unique mechanism of intra-peritoneal metastasis, already present in 80% of women at the time of diagnosis, making it the fifth leading cause of death from gynecological malignancy. Meta-analyses showed that obesity increases the risk of OvCa progression, leads to enhanced overall and organ-specific tumor burden, and adversely effects survival of women with OvCa. Recent data discovered that tumors grown in mice fed on a western diet (40% fat) have elevated lipid levels and a highly increased expression level of sterol regulatory element binding protein 1 (SREBP1). SREBP1 is a master transcription factor that regulates de novo lipogenesis and lipid homeostasis, and induces lipogenic reprogramming of tumor cells. Elevated SREBP1 levels are linked to cancer cell proliferation and metastasis. This review will summarize recent findings to provide a current understanding of lipid regulatory proteins in the ovarian tumor microenvironment with emphasis on SREBP1 expression in the obese host, the role of SREBP1 in cancer progression and metastasis, and potential therapeutic targeting of SREBPs and SREBP-pathway genes in treating cancers, particularly in the context of host obesity.

The fibrotic microenvironment promotes the metastatic seeding of tumor cells into the lungs via mediating the ZEB1-AS1/miR-200b-3p/ZEB1 signaling

Fibrotic microenvironment has been reported to have a pro-metastasis effect on tumor cells, but the mechanism remains unclear. The current study aimed to explore the underlying mechanism by which the fibrotic microenvironment affects tumor cells. A tumor metastasis model was established by injecting tumor cells containing GFP into mice with pulmonary fibrosis. Lung tissues and fibroblasts were harvested, and conditioned medium (CM) were collected from fibrotic lungs and fibroblasts. Hematoxylin & eosin staining and immunohistochemistry were used to detect pulmonary metastasis and FSP1 expression, respectively. Bioinformatics and dual-luciferase reporter assay proved that the target genes of ZEB1-AS1 and miR-200b-3p were miR-200b-3p and ZEB1, respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expressions of GFP, ZEB1-AS1, and miR-200b-3p. Transwell assay, Annexin V/PI assay, and colorimetry were performed to examine the effects of CM, ZEB1-AS1, miR-200b-3p, and ZEB1 on cell invasion, apoptosis, and the activity level of caspase-3/-9. Pulmonary metastasis was promoted and the expressions of FSP1 and GFP were increased in mice with pulmonary fibrosis. CM enhanced the invasion and inhibited the apoptosis of tumor cells. SiZEB1-AS1 and siZEB1 inhibited the invasion and apoptosis of tumor cells, while miR-200b-3p inhibitor had the opposite effect of SiZEB1-AS1 and siZEB1, and further reversed the effect of siZEB1 on tumor cell invasion and apoptosis. SiZEB1-AS1 reversed the effects of both miR-200b-3p inhibitor and miR-200b-3p inhibitor+siZEB1 on tumor cell invasion and apoptosis. Fibrotic microenvironment promoted the metastatic seeding of tumor cells into the lungs via mediating the ZEB1-AS1/miR-200b-3p/ZEB1 signaling.

Epithelial-mesenchymal interconversions in ovarian cancer: The levels and functions of E-cadherin in intraabdominal dissemination

The metastatic process of ovarian cancer (OC) is almost exclusively defined by direct shedding of tumor cells into the abdominal cavity, followed by clustering into multicellular aggregates and posterior peritoneal anchorage. This process relies on dynamic intercellular interactions which are modified by epithelial- mesenchymal interconversions and, therefore, E-cadherin expression variability. Although widely accepted as a tumor suppressor in many types of cancer, E-cadherin is currently known to have a dynamic expression and a much more complex role in OC. First, high E-cadherin expression is considered a sign of metaplasia in the normal ovarian epithelium, due to its association with epithelial growth factor receptor (EGFR) mediated cell proliferation. Subsequently, it is the decreased expression of E-cadherin that allows the acquisition of a more invasive phenotype, leading to the spread of primary tumor cells into the peritoneal fluid. This downregulation seems to depend on complex regulatory mechanisms, from molecular proteolysis to microenvironment interference and epigenetic regulation. E-cadherin cleavage and its resulting fragments appear to be essential to the process of dissemination and even to the formation of multicellular aggregates. Paradoxically, the maintenance of some E-cadherin expression seems to promote intercellular adhesion, resistance, and survival while decreasing cancer response to chemotherapy. Multiple studies have shown that reversing epithelial-mesenchymal transaction (EMT) and increasing E-cadherin expression prevents OC intraperitoneal dissemination, but findings that simultaneously correlate E-cadherin downregulation to higher chemotherapy sensitivity should not be ignored. Nevertheless, EMT and E-cadherin seem to have a potential interest as therapeutic targets in novel approaches to OC treatment.

Immune profiling reveals prognostic genes in high-grade serous ovarian cancer

High-grade serous ovarian cancer (HGSOC) is a heterogeneous disease with diverse clinical outcomes, highlighting a need for prognostic biomarker identification. Here, we combined tumor microenvironment (TME) scores with HGSOC characteristics to identify immune-related prognostic genes through analysis of gene expression profiles and clinical patient data from The Cancer Genome Atlas and the International Cancer Genome Consortium public cohorts. We found that high TME scores (TMEscores) based on the fractions of immune cell types correlated with better overall survival. Furthermore, differential expression analysis revealed 329 differentially expressed genes between patients with high vs. low TMEscores. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that these genes participated mainly in immune-related functions and, among them, 48 TME-related genes predicted overall survival in HGSOC. Seven of those genes were associated with prognosis in an independent HGSOC database. Finally, the two genes with the lowest p-values in the prognostic analysis (GBP1, ETV7) were verified through in vitro experiments. These findings reveal specific TME-related genes that could serve as effective prognostic biomarkers for HGSOC.

Adipose-Derived Stem Cells Primed with Paclitaxel Inhibit Ovarian Cancer Spheroid Growth and Overcome Paclitaxel Resistance

Adipose-derived stem cells (ADSCs) primed with paclitaxel (PTX) are now hypothesized to represent a potential Trojan horse to vehicle and deliver PTX into tumors. We analyzed the anticancer activity of PTX released by ADSCs primed with PTX (PTX-ADSCs) (~20 ng/mL) in a panel of ovarian cancer (OvCa) cells sensitive or resistant to PTX. We used two (2D) and three dimensional (3D) in vitro models (multicellular tumor spheroids, MCTSs, and heterospheroids) to mimic tumor growth in ascites. The coculture of OvCa cells with PTX-ADSCs inhibited cell viability in 2D models and in 3D heterospheroids (SKOV3-MCTSs plus PTX-ADSCs) and counteracted PTX-resistance in Kuramochi cells. The cytotoxic effects of free PTX and of equivalent amounts of PTX secreted in PTX-ADSC-conditioned medium (CM) were compared. PTX-ADSC-CM decreased OvCa cell proliferation, was more active than free PTX and counteracted PTX-resistance in Kuramochi cells (6.0-fold decrease in the IC50 values). Cells cultivated as 3D aggregated MCTSs were more resistant to PTX than 2D cultivation. PTX-ADSC-CM (equivalent-PTX) was more active than PTX in MCTSs and counteracted PTX-resistance in all cell lines. PTX-ADSC-CM also inhibited OvCa-MCTS dissemination on collagen-coated wells. In conclusion, PTX-ADSCs and PTX-MSCs-CM may represent a new option with which to overcome PTX-resistance in OvCa.