Loss of E-cadherin promotes ovarian cancer metastasis via alpha 5-integrin, which is a therapeutic target

Adipocyte derived exosomes promote cell invasion and challenge paclitaxel efficacy in ovarian cancer

BACKGROUND

Epithelial ovarian cancer (EOC) is the deadliest gynaecological cancer with high mortality rates driven by the common development of resistance to chemotherapy. EOC frequently invades the omentum, an adipocyte-rich organ of the peritoneum and omental adipocytes have been implicated in promoting disease progression, metastasis and chemoresistance. The signalling mechanisms underpinning EOC omentum tropism have yet to be elucidated.

METHODS

Three-dimensional co-culture models were used to explore adipocyte-EOC interactions. The impact of adipocytes on EOC proliferation, response to therapy and invasive capacity was assessed. Primary adipocytes and omental tissue were isolated from patients with ovarian malignancies and benign ovarian neoplasms. Exosomes were isolated from omentum tissue conditioned media and the effect of omentum-derived exosomes on EOC evaluated. Exosomal microRNA (miRNA) sequencing was used to identify miRNAs abundant in omental exosomes and EOC cells were transfected with highly abundant miRNAs miR-21, let-7b, miR-16 and miR-92a.

RESULTS

We demonstrate the capacity of adipocytes to induce an invasive phenotype in EOC populations through driving epithelial-to-mesenchymal transition (EMT). Exosomes secreted by omental tissue of ovarian cancer patients, as well as patients without malignancies, induced proliferation, upregulated EMT markers and reduced response to paclitaxel therapy in EOC cell lines and HGSOC patient samples. Analysis of the omentum-derived exosomes from cancer patients revealed highly abundant miRNAs that included miR-21, let-7b, miR-16 and miR-92a that promoted cancer cell proliferation and protection from chemotherapy when transfected in ovarian cancer cells.

CONCLUSIONS

These observations highlight the capacity of omental adipocytes to generate a pro-tumorigenic and chemoprotective microenvironment in ovarian cancer and other adipose-related malignancies.

Enhancing PKA-dependent mesothelial barrier integrity reduces ovarian cancer transmesothelial migration via inhibition of contractility

Cancer-mesothelial cell interactions are critical for multiple solid tumors to colonize the surface of peritoneal organs. Understanding mechanisms of mesothelial barrier dysfunction that impair its protective function is critical for discovering mesothelial-targeted therapies to combat metastatic spread. Here, we utilized a live cell imaging-based assay to elucidate the dynamics of ovarian cancer spheroid transmesothelial migration and mesothelial-generated mechanical forces. Treatment of mesothelial cells with the adenylyl cyclase agonist forskolin strengthens cell-cell junctions, reduces actomyosin fibers, contractility-driven matrix displacements, and cancer spheroid transmigration in a protein kinase A (PKA)-dependent mechanism. We also show that inhibition of the cytoskeletal regulator Rho-associated kinase in mesothelial cells phenocopies the anti-metastatic effects of forskolin. Conversely, upregulation of contractility in mesothelial cells disrupts cell-cell junctions and increases the clearance rates of ovarian cancer spheroids. Our findings demonstrate the critical role of mesothelial cell contractility and mesothelial barrier integrity in regulating metastatic dissemination within the peritoneal microenvironment.

Integrins as the pivotal regulators of cisplatin response in tumor cells

Cisplatin (CDDP) is a widely used first-line chemotherapeutic drug in various cancers. However, CDDP resistance is frequently observed in cancer patients. Therefore, it is required to evaluate the molecular mechanisms associated with CDDP resistance to improve prognosis among cancer patients. Integrins are critical factors involved in tumor metastasis that regulate cell-matrix and cell-cell interactions. They modulate several cellular mechanisms including proliferation, invasion, angiogenesis, polarity, and chemo resistance. Modification of integrin expression levels can be associated with both tumor progression and inhibition. Integrins are also involved in drug resistance of various solid tumors through modulation of the tumor cell interactions with interstitial matrix and extracellular matrix (ECM). Therefore, in the present review we discussed the role of integrin protein family in regulation of CDDP response in tumor cells. It has been reported that integrins mainly promoted the CDDP resistance through interaction with PI3K/AKT, MAPK, and WNT signaling pathways. They also regulated the CDDP mediated apoptosis in tumor cells. This review paves the way to suggest the integrins as the reliable therapeutic targets to improve CDDP response in tumor cells.

Deregulated circRNAs in Epithelial Ovarian Cancer With Activity in Preclinical In Vivo Models: Identification of Targets and New Modalities for Therapeutic Intervention

Epithelial ovarian cancer (EOC) is associated with a dismal prognosis due to development of resistance to chemotherapy and metastasis in the peritoneal cavity and distant organs. In order to identify new targets and treatment modalities we searched the literature for up- and and down-regulated circRNAs with efficacy in preclinical EOC-related in vivo systems. Our search yielded circRNAs falling into the following categories: cisplatin and paclitaxel resistance, transmembrane receptors, secreted factors, transcription factors, RNA splicing and processing factors, RAS pathway-related components, proteolysis and cell-cycle regulation, signaling-related proteins, and circRNAs regulating proteins in additional categories. These findings can be potentially translated by validation and manipulation of the corresponding targets, inhibition of circRNAs with antisense oligonucleotides (ASO), small interfering RNAs (siRNA) or small hairpin RNA (shRNA) or by reconstituting their activity.

E-cadherin and NF-κB expression in the vagina after ovarian ischemia and reperfusion

PURPOSE

To investigate inflammation and cell adhesion molecules in the vagina after ovarian ischemia-reperfusion (IR) injury.

METHODS

20 Wistar albino female rats were divided into two groups: control, and IR groups. In IR group, blood flow was restricted for 2 hours for ovarian ischemia. Then, tissues were re-blood 2 hours for reperfusion. Vagina tissues were excised and processed for histopathological analysis. Histopathological and biochemical follow-ups were performed.

RESULTS

Both malondialdehyde and myeloperoxidase values were increased in IR group compared to control group. Glutathione content was decreased in IR group compared to control group. Epithelial degeneration, inflammation, dilatation, and nuclear factor-κB (NF-κB) expression were increased in IR group compared to control group. E-cadherin expression was significantly decreased in IR group. In the IR group, E-cadherin showed a positive reaction in adenomas, gland-like cryptic structures, cellular junctions with clustered inflammatory cells. In the IR group, NF-κB expression was increased in basement membrane, inflammatory cells, in blood vessels.

CONCLUSIONS

Ovarian ischemia caused degeneration of epithelial cells in the vaginal region and disruptions in the cell junction complex, which leads to activation of E-cadherin and NF-κB signaling pathway and alterations in reproductive and embryonal development in the vaginal region.

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.

5-Hydroxymethylcytosine signals in serum are a predictor of chemoresistance in high-grade serous ovarian cancer

OBJECTIVE

The genome-wide profiling of 5-hydroxymethylcytosines (5hmC) on circulating cell-free DNA (cfDNA) has revealed promising biomarkers for various diseases. The purpose of this study was to investigate 5hmC signals in serum cfDNA and identify novel predictive biomarkers for the development of chemoresistance in high-grade serous ovarian cancer (HGSOC). We hypothesized that 5hmC profiles in cfDNA reflect the development of chemoresistance and elucidate pathways that may drive chemoresistance in HGSOC. Moreover, we sought to identify predictors that would better stratify outcomes for women with intermediate-sensitive HGSOC.

METHODS

Women diagnosed with HGSOC and known platinum sensitivity status were selected for this study. Nano-hmC-Seal was performed on cfDNA isolated from archived serum samples, and differential 5hmC features were identified using DESeq2 to establish a model predictive of chemoresistance.

RESULTS

A multivariate model consisting of three features (preoperative CA-125, largest residual implant after surgery, 5hmC level of OSGEPL), stratified samples from intermediate sensitive, chemo-naive women diagnosed with HGSOC into chemotherapy-resistant- and sensitive-like strata with a significant difference in overall survival (OS). Independent analysis of The Cancer Genome Atlas data further confirmed that high OSGEPL1 expression is a favorable prognostic factor for HGSOC.

CONCLUSIONS

We have developed a novel multivariate model based on clinico-pathologic data and a cfDNA-derived 5hmC modified gene, OSGEPL1, that predicted response to platinum-based chemotherapy in intermediate-sensitive HGSOC. Our multivariate model applies to chemo-naïve samples regardless if the patint was treated with adjuvant or neoadjuvant chemotherapy. These results merit further investigation of the predictive capability of our model in larger cohorts.

Modelling the complex nature of the tumor microenvironment: 3D tumor spheroids as an evolving tool

Cancer remains a serious burden in society and while the pace in the development of novel and more effective therapeutics is increasing, testing platforms that faithfully mimic the tumor microenvironment are lacking. With a clear shift from animal models to more complex in vitro 3D systems, spheroids emerge as strong options in this regard. Years of development have allowed spheroid-based models to better reproduce the biomechanical cues that are observed in the tumor-associated extracellular matrix (ECM) and cellular interactions that occur in both a cell-cell and cell-ECM manner. Here, we summarize some of the key cellular interactions that drive tumor development, progression and invasion, and how successfully are these interactions recapitulated in 3D spheroid models currently in use in the field. We finish by speculating on future advancements in the field and on how these can shape the relevance of spherical 3D models for tumor modelling.

Recent Progress in the Application of Exosome Analysis in Ovarian Cancer Management

Exosomes are very small (nano-sized) vesicles participating in tumor development by involvement in intercellular communication mediated by transferring biocomponents. Exosomes appear to play vital roles in various cancer development, such as ovarian cancer, a common malignancy in women. Several hallmarks of ovarian cancer are reported to be affected by the exosomemediated cellular cross-talk, including modulating peritoneal dissemination and chemoresistance. Since the expression of some biomolecules, such as miRNAs and mRNA, is changed in ovarian cancer, these exo-biomolecules can be applied as prognostic, diagnostic, and therapeutic biomarkers. Also, the selective loading of specific chemotherapeutic agents into exosomes highlights these biocarries as potential delivery devices. Exosomes could be artificially provided and engineered to better target the site of interest in ovarian cancer. In the present review, we summarize the notable achievement of exosome application in ovarian cancer management to gain applicable transitional insight against this cancer.

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.

Progress in the Treatment of Peritoneal Metastatic Cancer and the Application of Therapeutic Nanoagents

Peritoneal metastatic cancer is a cancer caused by the direct growth of cancer cells from the primary site through the bloodstream, lymph, or peritoneum, which is a difficult part of current clinical treatment. In the abdominal cavity of patients with metastatic peritoneal cancer, there are usually nodules of various sizes and malignant ascites. Among them, nodules of different sizes can obstruct intestinal movement and form intestinal obstruction, while malignant ascites can cause abdominal distension and discomfort, and even cause patients to have difficulty in breathing. The pathology and physiology of peritoneal metastatic cancer are complex and not fully understood. The main hypothesis is "seed" and "soil"; i.e., cells from the primary tumor are shed and implanted in the peritoneal cavity (peritoneal metastasis). In the last two decades, the main treatment modalities used clinically are cytoreductive surgery (CRS), systemic chemotherapy, intraperitoneal chemotherapy, and combined treatment, all of which help to improve patient survival and quality of life (QOL). However, the small-molecule chemotherapeutic drugs used clinically still have problems such as rapid drug metabolism and systemic toxicity. With the rapid development of nanotechnology in recent years, therapeutic nanoagents for the treatment of peritoneal metastatic cancer have been gradually developed, which has improved the therapeutic effect and reduced the systemic toxicity of small-molecule chemotherapeutic drugs to a certain extent. In addition, nanomaterials have been developed not only as therapeutic agents but also as imaging agents to guide peritoneal tumor CRS. In this review, we describe the etiology and pathological features of peritoneal metastatic cancer, discuss in detail the clinical treatments that have been used for peritoneal metastatic cancer, and analyze the advantages and disadvantages of the different clinical treatments and the QOL of the treated patients, followed by a discussion focusing on the progress, obstacles, and challenges in the use of therapeutic nanoagents in peritoneal metastatic cancer. Finally, therapeutic nanoagents and therapeutic tools that may be used in the future for the treatment of peritoneal metastatic cancer are prospected.

Matriptase drives dissemination of ovarian cancer spheroids by a PAR-2/PI3K/Akt/MMP9 signaling axis

The transmembrane serine protease matriptase is a key regulator of both barrier-disruptive and protective epithelial cell-cell interactions. Elevated matriptase is a consistent feature of epithelial ovarian cancers (OvCa), where multicellular spheroids shed from the primary tumor into the peritoneal cavity are critical drivers of metastasis. Dynamic cell-to-cell adhesive contacts are required for spheroid formation and maintenance. Here, we show that overactive matriptase, reflected in an increased ratio of matriptase to its inhibitor hepatocyte growth factor activator inhibitor 1 (HAI-1), disrupts cell-cell contacts to produce loose prometastatic spheroids that display increased mesothelial cell adhesion and submesothelial invasion. We show that these activities are dependent on the matriptase activation of a protease-activated receptor-2 (PAR-2) signaling pathway involving PI3K/Akt and MMP9-induced disruption of cell-cell adhesion by the release of the soluble E-cadherin ectodomain. These data reveal a novel pathological connection between matriptase activation of PAR-2 and disruption of cell-cell adhesion, and support the clinical investigation of this signaling axis as a therapeutic strategy for aggressive metastatic OvCa.

Lineage specific extracellular vesicle-associated protein biomarkers for the early detection of high grade serous ovarian cancer

High grade serous ovarian carcinoma (HGSOC) accounts for ~ 70% of ovarian cancer cases. Non-invasive, highly specific blood-based tests for pre-symptomatic screening in women are crucial to reducing the mortality associated with this disease. Since most HGSOCs typically arise from the fallopian tubes (FT), our biomarker search focused on proteins found on the surface of extracellular vesicles (EVs) released by both FT and HGSOC tissue explants and representative cell lines. Using mass spectrometry, 985 EV proteins (exo-proteins) were identified that comprised the FT/HGSOC EV core proteome. Transmembrane exo-proteins were prioritized because these could serve as antigens for capture and/or detection. With a nano-engineered microfluidic platform, six newly discovered exo-proteins (ACSL4, IGSF8, ITGA2, ITGA5, ITGB3, MYOF) plus a known HGSOC associated protein, FOLR1 exhibited classification performance ranging from 85 to 98% in a case-control study using plasma samples representative of early (including stage IA/B) and late stage (stage III) HGSOCs. Furthermore, by a linear combination of IGSF8 and ITGA5 based on logistic regression analysis, we achieved a sensitivity of 80% with 99.8% specificity and a positive predictive value of 13.8%. Importantly, these exo-proteins also can accurately discriminate between ovarian and 12 types of cancers commonly diagnosed in women. Our studies demonstrate that these lineage-associated exo-biomarkers can detect ovarian cancer with high specificity and sensitivity early and potentially while localized to the FT when patient outcomes are more favorable.

Structural analysis of peptide binding to integrins for cancer detection and treatment

Integrins are cell receptors involved in several metabolic pathways often associated with cell proliferation. Some of these integrins are downregulated during human physical development, but when these integrins are overexpressed in adult humans, they can be associated with several diseases, such as cancer. Molecules that specifically bind to these integrins are useful for cancer detection, diagnosis, and treatment. This review focuses on the structures of integrin-peptidic ligand complexes to dissect how the binding occurs and the molecular basis of the specificity and affinity of these peptidic ligands. Understanding these interactions at the molecular level is fundamental to be able to design new peptides that are more specific and more sensitive to a particular integrin. The integrin complexes covered in this review are α5β1, αIIbβ3, αvβ3, αvβ6, and αvβ8, because the molecular structures of the complex have been experimentally determined and their presence on tumor cancer cells are associated with a poor prognosis, making them targets for cancer detection and treatment.

Bioflavonoid luteolin prevents sFlt-1 release via HIF-1α inhibition in cultured human placenta

Preeclampsia (PE) is a serious hypertensive complication of pregnancy and is a leading cause of maternal death and major contributor to maternal and perinatal morbidity, including establishment of long-term complications. The continued prevalence of PE stresses the need for identification of novel treatments which can target prohypertensive factors implicated in the disease pathophysiology, such as soluble fms-like tyrosine kinase 1 (sFlt-1). We set out to identify novel compounds to reduce placental sFlt-1 and determine whether this occurs via hypoxia-inducible factor (HIF)-1α inhibition. We utilized a commercially available library of natural compounds to assess their ability to reduce sFlt-1 release from primary human placental cytotrophoblast cells (CTBs). Human placental explants from normotensive (NT) and preeclamptic (PE) pregnancies were treated with varying concentrations of luteolin. Protein and mRNA expression of sFlt-1 and upstream mediators were evaluated using ELISA, western blot, and real-time PCR. Of the natural compounds examined, luteolin showed the most potent inhibition of sFlt-1 release, with >95% reduction compared to vehicle-treated. Luteolin significantly inhibited sFlt-1 in cultured placental explants compared to vehicle-treated in a dose- and time-dependent manner. Additionally, significant decreases in HIF-1α expression were observed in luteolin-treated explants, suggesting a mechanism for sFlt-1 downregulation. The ability of luteolin to inhibit HIF-1α may be mediated through the Akt pathway, as inhibitors to Akt and its upstream regulator phosphatidylinositol-3 kinase (PI3K) resulted in significant HIF-1α reduction. Luteolin reduces anti-angiogenic sFlt-1 through inhibition of HIF-1α, making it a novel candidate for the treatment of PE.

Lineage specific extracellular vesicle-associated protein biomarkers for the early detection of high grade serous ovarian cancer

High grade serous ovarian carcinoma (HGSOC) accounts for ~ 70% of ovarian cancer cases. Non-invasive, highly specific blood-based tests for pre-symptomatic screening in women are crucial to reducing the mortality associated with this disease. Since most HGSOCs typically arise from the fallopian tubes (FT), our biomarker search focused on proteins found on the surface of extracellular vesicles (EVs) released by both FT and HGSOC tissue explants and representative cell lines. Using mass spectrometry, 985 EV proteins (exo-proteins) were identified that comprised the FT/HGSOC EV core proteome. Transmembrane exo-proteins were prioritized because these could serve as antigens for capture and/or detection. With a nano-engineered microfluidic platform, six newly discovered exo-proteins (ACSL4, IGSF8, ITGA2, ITGA5, ITGB3, MYOF) plus a known HGSOC associated protein, FOLR1 exhibited classification performance ranging from 85-98% in a case-control study using plasma samples representative of early (including stage IA/B) and late stage (stage III) HGSOCs. Furthermore, by linear combination of IGSF8 and ITGA5 based on logistic regression analysis, we achieved a sensitivity of 80% (99.8% specificity). These lineage-associated exo-biomarkers have potential to detect cancer while localized to the FT when patient outcomes are more favorable.

Nanotechnology-integrated ovarian cancer metastasis therapy: Insights from the metastatic mechanisms into administration routes and therapy strategies

Ovarian cancer is a kind of malignant tumour which locates in the pelvic cavity without typical clinical symptoms in the early stages. Most patients are diagnosed in the late stage while about 60 % of them have suffered from the cancer cells spreading in the abdominal cavity. The high recurrence rate and mortality seriously damage the reproductive needs and health of women. Although recent advances in therapeutic regimes and other adjuvant therapies improved the overall survival of ovarian cancer, overcoming metastasis has still been a challenge and is necessary for achieving cure of ovarian cancer. To present potential targets and new strategies for curbing the occurrence of ovarian metastasis and the treatment of ovarian cancer after metastasis, the first section of this paper explained the metastatic mechanisms of ovarian cancer comprehensively. Nanomedicine, not limited to drug delivery, offers opportunities for metastatic ovarian cancer therapy. The second section of this paper emphasized the advantages of various administration routes of nanodrugs in metastatic ovarian cancer therapy. Furthermore, the third section of this paper focused on advances in nanotechnology-integrated strategies for targeting metastatic ovarian cancer based on the metastatic mechanisms of ovarian cancer. Finally, the challenges and prospects of nanotherapeutics for ovarian cancer metastasis therapy were evaluated. In general, the greatest emphasis on using nanotechnology-based strategies provides avenues for improving metastatic ovarian cancer outcomes in the future.

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.

Tumor microenvironment in ovarian cancer peritoneal metastasis

Ovarian cancer (OC) is one of the most common gynecological malignancies with high morbidity and mortality. The peritoneum is one of the most common metastatic sites in ovarian cancer, involving large amounts of ascites. However, its mechanism is unclear. The peritoneal microenvironment composed of peritoneal effusion and peritoneum creates favorable conditions for ovarian cancer progression and metastasis. Here, we reviewed the peritoneal metastasis patterns and molecular mechanisms of ovarian cancer, as well as major components of the peritoneal microenvironment, peritoneal effusion, and immune microenvironment, and investigated the relationship between the peritoneal microenvironment and ovarian cancer metastasis.

LACTB exerts tumor suppressor properties in epithelial ovarian cancer through regulation of Slug

Epithelial-mesenchymal transition (EMT) is a cellular mechanism used by cancer cells to acquire migratory and stemness properties. In this study, we show, through in vitro, in vivo, and 3D culture experiments, that the mitochondrial protein LACTB manifests tumor suppressor properties in ovarian cancer. We show that LACTB is significantly down-regulated in epithelial ovarian cancer cells and clinical tissues. Re-expression of LACTB negatively effects the growth of cancer cells but not of non-tumorigenic cells. Mechanistically, we show that LACTB leads to differentiation of ovarian cancer cells and loss of their stemness properties, which is achieved through the inhibition of the EMT program and the LACTB-dependent down-regulation of Snail2/Slug transcription factor. This study uncovers a novel role of LACTB in ovarian cancer and proposes new ways of counteracting the oncogenic EMT program in this model system.

L1CAM is required for early dissemination of fallopian tube carcinoma precursors to the ovary

Most ovarian high-grade serous carcinomas (HGSC) arise from Serous Tubal Intraepithelial Carcinoma (STIC) lesions in the distal end of the fallopian tube (FT). Formation of STIC lesions from FT secretory cells leads to seeding of the ovarian surface, with rapid tumor dissemination to other abdominal structures thereafter. It remains unclear how nascent malignant cells leave the FT to colonize the ovary. This report provides evidence that the L1 cell adhesion molecule (L1CAM) contributes to the ability of transformed FT secretory cells (FTSEC) to detach from the tube, survive under anchorage-independent conditions, and seed the ovarian surface. L1CAM was highly expressed on the apical cells of STIC lesions and contributed to ovarian colonization by upregulating integrins and fibronectin in malignant cells and activating the AKT and ERK pathways. These changes increased cell survival under ultra-low attachment conditions that mimic transit from the FT to the ovary. To study dissemination to the ovary, we developed a tumor-ovary co-culture model. We showed that L1CAM expression was important for FT cells to invade the ovary as a cohesive group. Our results indicate that in the early stages of HGSC development, transformed FTSECs disseminate from the FT to the ovary in a L1CAM-dependent manner.

Regulation of the aryl hydrocarbon receptor in cancer and cancer stem cells of gynecological malignancies: An update on signaling pathways

Gynecological malignancies are a female type of cancers that affects the reproductive system. Cancer metastasis or recurrence mediated by cellular invasiveness occurs at advanced stages of cancer progression. Cancer Stem Cells (CSCs) enrichment in tumors leads to chemoresistance, which results in cancer mortality. Exposure to environmental pollutants such as polycyclic aromatic hydrocarbons is associated with an increased the risk of CSC enrichment in gynecological cancers. One of the important pathways that mediates the metabolism and bioactivation of these environmental chemicals is the transcription factor, aryl hydrocarbon receptor (AhR). The present review explores the molecular mechanisms regulating the crosstalk and interaction of the AhR with cancer-related signaling pathways, such as apoptosis, epithelial-mesenchymal transition, immune checkpoints, and G-protein-coupled receptors in several gynecological malignancies such as ovarian, uterine, endometrial, and cervical cancers. The review also discusses the potential of targeting the AhR pathway as a novel chemotherapy for gynecological cancers.

Ovarian Cancer Metastasis to the Central Nervous System: A Literature Review

Ovarian cancer is one of the leading causes of cancer-related deaths among women in the United States. Metastasis to the central nervous system has become more frequent in the previous decades, however, treatment options remain limited. In this review, we discuss the pathophysiology of ovarian cancer and how metastasis to the central nervous system typically occurs. We then discuss cases of metastasis presented in the literature to evaluate current treatment regimens and protocols. Finally, we highlight emerging treatment options that are being utilized in clinics to provide personalized treatment therapy for a patient's unique diagnosis. This review aims to further the understanding of pathophysiology, stimulate further innovative treatments, and present accessible resources through tables and figures.

Reduced Graphene Oxide Modulates the FAK-Dependent Signaling Pathway in Glioblastoma Multiforme Cells In Vitro

Aggressive invasiveness is a common feature of malignant gliomas, despite their high level of tumor heterogeneity and possible diverse cell origins. Therefore, it is important to explore new therapeutic methods. In this study, we evaluated and compared the effects of graphene (GN) and reduced graphene oxides (rGOs) on a highly invasive and neoplastic cell line, U87. The surface functional groups of the GN and rGO flakes were characterized by X-ray photoelectron spectroscopy. The antitumor activity of these flakes was obtained by using the neutral red assay and their anti-migratory activity was determined using the wound healing assay. Further, we investigated the mRNA and protein expression levels of important cell adhesion molecules involved in migration and invasiveness. The rGO flakes, particularly rGO/ATS and rGO/TUD, were found highly toxic. The migration potential of both U87 and Hs5 cells decreased, especially after rGO/TUD treatment. A post-treatment decrease in mobility and FAK expression was observed in U87 cells treated with rGO/ATS and rGO/TUD flakes. The rGO/TUD treatment also reduced β-catenin expression in U87 cells. Our results suggest that rGO flakes reduce the migration and invasiveness of U87 tumor cells and can, thus, be used as potential antitumor agents.

Glycosphingolipids are mediators of cancer plasticity through independent signaling pathways

The molecular repertoire promoting cancer cell plasticity is not fully elucidated. Here, we propose that glycosphingolipids (GSLs), specifically the globo and ganglio series, correlate and promote the transition between epithelial and mesenchymal cells. The epithelial character of ovarian cancer remains stable throughout disease progression, and spatial glycosphingolipidomics reveals elevated globosides in the tumor compartment compared with the ganglioside-rich stroma. CRISPR-Cas9 knockin mediated truncation of endogenous E-cadherin induces epithelial-to-mesenchymal transition (EMT) and decreases globosides. The transcriptomics analysis identifies the ganglioside-synthesizing enzyme ST8SIA1 to be consistently elevated in mesenchymal-like samples, predicting poor outcome. Subsequent deletion of ST8SIA1 induces epithelial cell features through mTOR^S2448 phosphorylation, whereas loss of globosides in ΔA4GALT cells, resulting in EMT, is accompanied by increased ERK^Y202/T204 and AKT^S124. The GSL composition dynamics corroborate cancer cell plasticity, and further evidence suggests that mesenchymal cells are maintained through ganglioside-dependent, calcium-mediated mechanisms.

Pharmacologic Targeting of MMP2/9 Decreases Peritoneal Metastasis Formation of Colorectal Cancer in a Human Ex Vivo Peritoneum Culture Model

Simple Summary

We investigated the effects of matrix metalloproteinases (MMPs) on the peritoneal attachment of colorectal cancer cells in patient samples and in a human ex vivo peritoneum model. MMP2/9 overexpression and enhanced fibronectin cleavage occurred during peritoneal colonisation, which could be inhibited by specific MMP inhibition, thereby reducing cancer cell attachment.

Abstract

Background: Matrix metalloproteinases (MMPs) play a crucial role in tumour initiation, progression, and metastasis, including peritoneal carcinosis (PC) formation. MMPs serve as biomarkers for tumour progression in colorectal cancer (CRC), and MMP overexpression is associated with advanced-stage metastasis and poor survival. However, the molecular mechanisms of PC from CRC remain largely unclear. Methods: We investigated the role of MMPs during peritoneal colonisation by CRC cell lines in a human ex vivo peritoneum model and in patient-derived CRC and corresponding PC samples. MMP2 and MMP9 were inhibited using the small-molecule inhibitors batimastat and the specific MMP2/9 inhibitor III. Results: MMP2 and MMP9 were strongly upregulated in patient-derived samples and following peritoneal colonisation by CRC cells in the ex vivo model. MMP inhibition with batimastat reduced colonisation of HT29 and Colo205 cells by 36% and 68%, respectively (p = 0.0073 and p = 0.0002), while MMP2/9 inhibitor III reduced colonisation by 50% and 41%, respectively (p = 0.0003 and p = 0.0051). Fibronectin cleavage was enhanced in patient-derived samples of PC and during peritoneal colonisation in the ex vivo model, and this was inhibited by MMP2/9 inhibition. Conclusion: MMPs were upregulated in patient-derived samples and during peritoneal attachment of CRC cell lines in our ex vivo model. MMP2/9 inhibition prevented fibronectin cleavage and peritoneal colonisation by CRC cells. MMP inhibitors might thus offer a potential treatment strategy for patients with PC.

Targeting LRRC15 Inhibits Metastatic Dissemination of Ovarian Cancer

Dissemination of ovarian cancer cells can lead to inoperable metastatic lesions in the bowel and omentum that cause patient death. Here we show that LRRC15, a type-I 15-leucine-rich repeat-containing membrane protein, highly overexpressed in ovarian cancer bowel metastases compared with matched primary tumors and acts as a potent promoter of omental metastasis. Complementary models of ovarian cancer demonstrated that LRRC15 expression leads to inhibition of anoikis-induced cell death and promotes adhesion and invasion through matrices that mimic omentum. Mechanistically, LRRC15 interacted with β1-integrin to stimulate activation of focal adhesion kinase (FAK) signaling. As a therapeutic proof of concept, targeting LRRC15 with the specific antibody-drug conjugate ABBV-085 in both early and late metastatic ovarian cancer cell line xenograft models prevented metastatic dissemination, and these results were corroborated in metastatic patient-derived ovarian cancer xenograft models. Furthermore, treatment of 3D-spheroid cultures of LRRC15-positive patient-derived ascites with ABBV-085 reduced cell viability. Overall, these data uncover a role for LRRC15 in promoting ovarian cancer metastasis and suggest a novel and promising therapy to target ovarian cancer metastases.

Significance: This study identifies that LRRC15 activates β1-integrin/FAK signaling to promote ovarian cancer metastasis and shows that the LRRC15-targeted antibody-drug conjugate ABBV-085 suppresses ovarian cancer metastasis in preclinical models.

Gynecologic Cancer, Cancer Stem Cells, and Possible Targeted Therapies

Gynecologic cancer is one of the main causes of death in women. In this type of cancer, several molecules (oncogenes or tumor suppressor genes) contribute to the tumorigenic process, invasion, metastasis, and resistance to treatment. Based on recent evidence, the detection of molecular changes in these genes could have clinical importance for the early detection and evaluation of tumor grade, as well as the selection of targeted treatment. Researchers have recently focused on cancer stem cells (CSCs) in the treatment of gynecologic cancer because of their ability to induce progression and recurrence of malignancy. This has highlighted the importance of a better understanding of the molecular basis of CSCs. The purpose of this review is to focus on the molecular mechanism of gynecologic cancer and the role of CSCs to discover more specific therapeutic approaches to gynecologic cancer treatment.

The proprotein convertase furin in cancer: more than an oncogene

Furin is the first discovered proprotein convertase member and is present in almost all mammalian cells. Therefore, by regulating the maturation of a wide range of proproteins, Furin expression and/or activity is involved in various physiological and pathophysiological processes ranging from embryonic development to carcinogenesis. Since many of these protein precursors are involved in initiating and maintaining the hallmarks of cancer, Furin has been proposed as a potential target for treating several human cancers. In contrast, other studies have revealed that some types of cancer do not benefit from Furin inhibition. Therefore, understanding the heterogeneous functions of Furin in cancer will provide important insights into the design of effective strategies targeting Furin in cancer treatment. Here, we present recent advances in understanding how Furin expression and activity are regulated in cancer cells and their influences on the activity of Furin substrates in carcinogenesis. Furthermore, we discuss how Furin represses tumorigenic properties of several cancer cells and why Furin inhibition leads to aggressive phenotypes in other tumors. Finally, we summarize the clinical applications of Furin inhibition in treating human cancers.

Ex Vivo Ovarian Culture to Model the Initial Metastasis in Ovarian Cancer

Being able to accurately model metastasis is an important tool in cancer research. Several in vitro and ex vivo models have been developed to model metastasis from the ovary to the omentum, the most frequent metastatic site after leaving the ovary. However, the recent discovery that high-grade serous ovarian cancer (HGSOC) can originate in the fallopian tube and then metastasize to the ovary has necessitated the development of assays that can quantify the adhesion of tumor cells to the ovary. Here we describe a protocol for accessing the adhesion of fluorescent cells to mouse ovaries. This assay can be used to investigate the role of ovarian function, hormones, and adhesion molecules in metastasis of cancer cells originating in the fallopian tube to the ovary, an important step in the progression of HGSOC.

Construction of a prognostic classifier and prediction of the immune landscape and immunosuppressive molecules in gliomas based on combination of inflammatory response-related genes and angiogenesis-associated genes

Objective:We aimed to combine inflammatory response-related genes (IRRGs) and angiogenesis-associated genes (AAGs) to build a prognostic classifier and to predict immune landscapes and immunosuppressive molecules in gliomas.

Introduction: Gliomas, the commonest primary brain tumors, account for about 80% of cancerous tumors in the central nervous system (CNS), featuring rapid progression, high malignancy, and extremely poor prognosis. The induction of inflammatory responses and angiogenesis have been considered to be closely related to tumors. However, there are little publications systematically elaborating on their impacts on gliomas.

Methods: We downloaded the data of IRRGs and AAGs from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) databases, and retrieved 68 differentially expressed genes (DEGs), of which 13 DEGs pertained to the prognosis of glioma cases. Next, 9 DEGs were screened from the 13 major DEGs with predictive significance and utilized to build a 9-gene signature as a prognostic risk score model (PRSM) with the aid of univariate Cox regression analyses (CRA) and least absolute shrinkage and selection operator (LASSO)-CRA. On this basis, glioma patients fell into high-risk (HR) group and low-risk (LR) group. Later, we implemented Gene Set Enrichment Analysis (GSEA, Gene Set: WP_ANGIOGENESIS) and calculate the scores of cell infiltration and immune-associated function by harnessing single-sample GSEA (ssGSEA).

Results: The prognosis was compared between the two groups by introducing Kaplan-Meier (KM) analysis, which yielded that HR group exhibited poorer prognosis. Additionally, the predictive capacity and independent characteristics were proven by the receiver operating characteristic curve (ROC) and multivariate CRA. Further, We took an evaluation of immune profiles, which unraveled that immunosuppressive cell count was distinctively larger in HS group. Finally, a protein-protein interaction (PPI) network of DEGs was built, and 10 hub genes were obtained, of which epidermal growth factor receptor (EGFR) was closely related to poor prognosis.

Conclusion: A 9-gene signature was established on the strength of IRRGs and AAGs for predicting glioma prognosis, tumor microenvironment (TME), immune landscapes and immunosuppressive molecules. However, the molecular mechanism developed by this signature to function in tumor immunity needs further experimental research in the future and is expected to be a research target for glioma immunotherapy strategies.

c-Met-integrin cooperation: Mechanisms, tumorigenic effects, and therapeutic relevance

c-Met is a receptor tyrosine kinase which upon activation by its ligand, the hepatocyte growth factor, mediates many important signalling pathways that regulate cellular functions such as survival, proliferation, and migration. Its oncogenic and tumorigenic signalling mechanisms, greatly contributing to cancer development and progression, are well documented. Integrins, heterogeneous adhesion receptors which facilitate cell-extracellular matrix interactions, are important in biomechanically sensitive cell adhesion and motility but also modulate diverse cell behaviour. Here we review the studies which reported cooperation between c-Met and several integrins, particularly β1 and β4, in various cell models including many tumour cell types. From the various experimental models and results analysed, we propose that c-Met-integrin cooperation occurs via inside-out or outside-in signalling. Thus, either c-Met activation triggers integrin activation and cell adhesion or integrin adhesion to its extracellular ligand triggers c-Met activation. These two modes of cooperation require the adhesive function of integrins and mostly lead to cell migration and invasion. In a third, less conventional, mode of cooperation, the integrin plays the role of a signalling adaptor for c-Met, independently from its adhesive property, leading to anchorage independent survival. Recent studies have revealed the influence of endocytic trafficking in c-Met-integrin cooperation including the adaptor function of integrin occurring on endomembranes, triggering an inside-in signalling, believed to promote survival of metastatic cells. We present the evidence of the cooperation in vivo and in human tissues and highlight its therapeutic relevance. A better understanding of the mechanisms regulating c-Met-integrin cooperation in cancer progression could lead to the design of new therapies targeting this cooperation, providing more effective therapeutic approaches than c-Met or integrin inhibitors as monotherapies used in the clinic.

Molecular and cellular mechanisms controlling integrin-mediated cell adhesion and tumor progression in ovarian cancer metastasis: a review

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy in the developed world. EOC metastasis is unique since malignant cells detach directly from the primary tumor site into the abdominal fluid and form multicellular aggregates, called spheroids, that possess enhanced survival mechanisms while in suspension. As such, altered cell adhesion properties are paramount to EOC metastasis with cell detachment from the primary tumor, dissemination as spheroids, and reattachment to peritoneal surfaces for secondary tumor formation. The ability for EOC cells to establish and maintain cell–cell contacts in spheroids is critical for cell survival in suspension. Integrins are a family of cell adhesion receptors that play a crucial role in cell–cell and cell-extracellular matrix interactions. These glycoprotein receptors regulate diverse functions in tumor cells and are implicated in multiple steps of cancer progression. Altered integrin expression is detected in numerous carcinomas, where they play a role in cell migration, invasion, and anchorage-independent survival. Like that observed for other carcinomas, epithelial-mesenchymal transition (EMT) occurs during metastasis and integrins can function in this process as well. Herein, we provide a review of the evidence for integrin-mediated cell adhesion mechanisms impacting steps of EOC metastasis. Taken together, targeting integrin function may represent a potential therapeutic strategy to inhibit progression of advanced EOC.

Integrin α5 mediates cancer cell-fibroblast adhesion and peritoneal dissemination of diffuse-type gastric carcinoma

Diffuse-type gastric carcinoma (DGC) has a poor prognosis due to its rapid diffusive infiltration and frequent peritoneal dissemination. DGC is associated with massive fibrosis caused by aberrant proliferation of cancer-associated fibroblasts (CAFs). Previously, we reported that direct heterocellular interaction between cancer cells and CAFs is important for the peritoneal dissemination of DGC. In this study, we aimed to identify and target the molecules that mediate such heterocellular interactions. Monoclonal antibodies (mAbs) against intact DGC cells were generated and subjected to high-throughput screening to obtain several mAbs that inhibit the adhesion of DGC cells to CAFs. Immunoprecipitation and mass spectrometry revealed that all mAbs recognized integrin α5 complexed with integrin β1. Blocking integrin α5 in DGC cells or fibronectin, a ligand of integrin α5β1, deposited on CAFs abrogated the heterocellular interaction. Administration of mAbs or knockout of integrin α5 in DGC cells suppressed their invasion led by CAFs in vitro and peritoneal dissemination in a mouse xenograft model. Altogether, these findings demonstrate that integrin α5 mediates the heterotypic cancer cell-fibroblast interaction during peritoneal dissemination of DGC and may thus be a therapeutic target.

Role of integrins in the metastatic spread of high-grade serous ovarian cancer

PURPOSE

Integrins may be involved in the metastatic spread of high-grade serous ovarian cancer (HGSOC) which determines the therapeutical approach and prognosis. We investigated the integrin expression in primary tumor and metastases of advanced HGSOC.

METHODS

The expression of integrin α2, α4, α5, α6, and β1 was assessed by immunostaining in tumor samples of the ovary, omentum, and peritoneum of each patient. Differences in integrin expression among tumor localizations and their association with clinicopathological parameters were examined by Fisher's exact test. The impact of integrin expression on progression-free survival (PFS) and overall survival (OS) was examined by Cox regression and Kaplan-Meier analyses.

RESULTS

Hundred and thirteen tumor samples of 40 HGSOC patients were examined. The expression of the integrins did not differ between the three tumor localizations (all p values > 0.05) with the exception of high expression of integrin α4 in primary tumor and omentum (52.5% versus 47.5%, p = 0.008) and primary tumor and peritoneum (52.5% versus 47.5%, p = 0.050). High expression of integrin α4 in peritoneum was associated with poorer PFS (HR 2.02 95% CI 1.01-4.05, p = 0.047), younger age (p = 0.047), and death (p = 0.046). Median PFS in patients with high expression of integrin α4 was 13.00 months, whereas median PFS in patients without high expression of integrin α4 was 21.00 months (p = 0.040). Expression of other integrins did not correlate with PFS or OS.

CONCLUSION

Expression of integrin α4 may be altered during the metastatic spread of HGSOC and affect prognosis, whereas expression of integrin α2, α5, α6, and β1 did not reveal any prognostic value.

Personalized models of heterogeneous 3D epithelial tumor microenvironments: Ovarian cancer as a model

Intractable human diseases such as cancers, are context dependent, unique to both the individual patient and to the specific tumor microenvironment. However, conventional cancer treatments are often nonspecific, targeting global similarities rather than unique drivers. This limits treatment efficacy across heterogeneous patient populations and even at different tumor locations within the same patient. Ultimately, this poor efficacy can lead to adverse clinical outcomes and the development of treatment-resistant relapse. To prevent this and improve outcomes, it is necessary to be selective when choosing a patient's optimal adjuvant treatment. In this review, we posit the use of personalized, tumor-specific models (TSM) as tools to achieve this remarkable feat. First, using ovarian cancer as a model disease, we outline the heterogeneity and complexity of both the cellular and extracellular components in the tumor microenvironment. Then we examine the advantages and disadvantages of contemporary cancer models and the rationale for personalized TSM. We discuss how to generate precision 3D models through careful and detailed analysis of patient biopsies. Finally, we provide clinically relevant applications of these versatile personalized cancer models to highlight their potential impact. These models are ideal for a myriad of fundamental cancer biology and translational studies. Importantly, these approaches can be extended to other carcinomas, facilitating the discovery of new therapeutics that more effectively target the unique aspects of each individual patient's TME. STATEMENT OF SIGNIFICANCE: In this article, we have presented the case for the application of biomaterials in developing personalized models of complex diseases such as cancers. TSM could bring about breakthroughs in the promise of precision medicine. The critical components of the diverse tumor microenvironments, that lead to treatment failures, include cellular- and extracellular matrix- heterogeneity, and biophysical signals to the cells. Therefore, we have described these dynamic components of the tumor microenvironments, and have highlighted how contemporary biomaterials can be utilized to create personalized in vitro models of cancers. We have also described the application of the TSM to predict the dynamic patterns of disease progression, and predict effective therapies that can produce durable responses, limit relapses, and treat any minimal residual disease.

Malignant Ascites in Ovarian Cancer: Cellular, Acellular, and Biophysical Determinants of Molecular Characteristics and Therapy Response

Ascites refers to the abnormal accumulation of fluid in the peritoneum resulting from an underlying pathology, such as metastatic cancer. Among all cancers, advanced-stage epithelial ovarian cancer is most frequently associated with the production of malignant ascites and is the leading cause of death from gynecologic malignancies. Despite decades of evidence showing that the accumulation of peritoneal fluid portends the poorest outcomes for cancer patients, the role of malignant ascites in promoting metastasis and therapy resistance remains poorly understood. This review summarizes the current understanding of malignant ascites, with a focus on ovarian cancer. The first section provides an overview of heterogeneity in ovarian cancer and the pathophysiology of malignant ascites. Next, analytical methods used to characterize the cellular and acellular components of malignant ascites, as well the role of these components in modulating cell biology, are discussed. The review then provides a perspective on the pressures and forces that tumors are subjected to in the presence of malignant ascites and the impact of physical stress on therapy resistance. Treatment options for malignant ascites, including surgical, pharmacological and photochemical interventions are then discussed to highlight challenges and opportunities at the interface of drug discovery, device development and physical sciences in oncology.

A Review of Principal Studies on the Development and Treatment of Epithelial Ovarian Cancer in the Laying Hen Gallus gallus

Often referred to as the silent killer, ovarian cancer is the most lethal gynecologic malignancy. This disease rarely shows any physical symptoms until late stages and no known biomarkers are available for early detection. Because ovarian cancer is rarely detected early, the physiology behind the initiation, progression, treatment, and prevention of this disease remains largely unclear. Over the past 2 decades, the laying hen has emerged as a model that naturally develops epithelial ovarian cancer that is both pathologically and histologically similar to that of the human form of the disease. Different molecular signatures found in human ovarian cancer have also been identified in chicken ovarian cancer including increased CA125 and elevated E-cadherin expression, among others. Chemoprevention studies conducted in this model have shown that decreased ovulation and inflammation are associated with decreased incidence of ovarian cancer development. The purpose of this article is to review the major studies performed in laying hen model of ovarian cancer and discuss how these studies shape our current understanding of the pathophysiology, prevention, and treatment of epithelial ovarian cancer.

Krüppel-like factor 9 upregulates E-cadherin transcription and represses breast cancer invasion and metastasis

Aberrant expression of Krüppel-like factor 9 (KLF9) is frequently found in some types of cancer and is implicated in cancer initiation and progression. However, the effects of KLF9 on cancer metastases and the underlying mechanisms still need to be understood. Here, we found that KLF9 evidently inhibited the capabilities of migration and invasion of breast cancer cells. The expression of KLF9 was markedly decreased in breast cancer patients compared with benign tumors, and was positively correlated with the expression of E-cadherin in the tissues of breast cancer patients. Mechanistically, chromatin immunoprecipitation combined with site-directed mutagenesis-luciferase assay revealed that KLF9 activated the E-cadherin promoter by binding to GT-box elements located +84 bp and -143 bp from the TSS in the E-cadherin promoter, leading to elevated expression of E-cadherin mRNA and protein. In vivo experiments confirmed that KLF9 strongly inhibited the lung metastasis of breast cancer and increased mouse E-cadherin expression in 4T1 mouse breast cancer cells. Taken together, our findings demonstrated that KLF9 could suppress breast cancer invasion and metastasis by upregulating E-cadherin, which provided new insight into aggressive treatment of breast cancer by targeting the KLF9/E-cadherin axis.

CDH6-activated αIIbβ3 crosstalks with α2β1 to trigger cellular adhesion and invasion in metastatic ovarian and renal cancers

Cadherin 6 (CDH6) is significantly overexpressed in advanced ovarian and renal cancers. However, the role of CDH6 in cancer metastasis is largely unclear. Here, we investigated the impact of CDH6 expression on integrin-mediated metastatic progression. CDH6 preferentially bound to αIIbβ3 integrin, a platelet receptor scarcely expressed in cancer cells, and this interaction was mediated through the cadherin Arginine-glycine-aspartic acid (RGD) motif. Furthermore, CDH6 and CDH17 were found to interact with α2β1 in αIIbβ3low cells. Transient silencing of CDH6, ITGA2B, or ITGB3 genes caused a significant loss of proliferation, adhesion, invasion, and lung colonization through the downregulation of SRC, FAK, AKT, and ERK signaling. In ovarian and renal cancer cells, integrin αIIbβ3 activation appears to be a prerequisite for proper α2β1 activation. Interaction of αIIbβ3 with CDH6, and subsequent αIIbβ3 activation, promoted activation of α2β1 and cell adhesion in ovarian and renal cancer cells. Additionally, monoclonal antibodies specific to the cadherin RGD motif and clinically approved αIIbβ3 inhibitors could block pro-metastatic activity in ovarian and renal tumors. In summary, the interaction between CDH6 and αIIbβ3 regulates α2β1-mediated adhesion and invasion of ovarian and renal cancer metastatic cells and constitutes a therapeutic target of broad potential for treating metastatic progression.

Sonosensitizer-Functionalized Graphene Nanoribbons for Adhesion Blocking and Sonodynamic Ablation of Ovarian Cancer Spheroids

Advanced stage ovarian cancer is challenging to treat due to widespread seeding of tumor spheroids throughout the mesothelial lining of the peritoneal cavity. In this work, a therapeutic strategy using graphene nanoribbons (GNR) functionalized with 4-arm polyethylene glycol (PEG) and chlorin e6 (Ce6), a sonosensitizer, to target metastatic ovarian cancer spheroids is reported. GNR-PEG-Ce6 adsorbs onto the spheroids and disrupts their adhesion to extracellular matrix proteins or LP-9 mesothelial cells. Furthermore, for spheroids that do adhere, GNR-PEG-Ce6 delays spheroid disaggregation and spreading as well as mesothelial clearance, key metastatic processes following adhesion. Owing to the sonodynamic effects of Ce6 and its localized delivery via the biomaterial, GNR-PEG-Ce6 can kill ovarian cancer spheroids adhered to LP-9 cell monolayers when combined with mild ultrasound irradiation. The interaction with GNR-PEG-Ce6 also loosens cell-cell adhesions within the spheroids, rendering them more susceptible to treatment with the chemotherapeutic agents cisplatin and paclitaxel, which typically have difficulty in penetrating ovarian cancer spheroids. Thus, this material can facilitate effective chemotherapeutic and sonodynamic combination therapies. Finally, the adhesion inhibiting and sonodynamic effects of GNR-PEG-Ce6 are also validated with tumor spheroids derived from the ascites fluid of ovarian cancer patients, providing evidence of the translational potential of this biomaterial approach.

Comprehensive understanding of anchorage-independent survival and its implication in cancer metastasis

Detachment is the initial and critical step for cancer metastasis. Only the cells that survive from detachment can develop metastases. Following the disruption of cell-extracellular matrix (ECM) interactions, cells are exposed to a totally different chemical and mechanical environment. During which, cells inevitably suffer from multiple stresses, including loss of growth stimuli from ECM, altered mechanical force, cytoskeletal reorganization, reduced nutrient uptake, and increased reactive oxygen species generation. Here we review the impact of these stresses on the anchorage-independent survival and the underlying molecular signaling pathways. Furthermore, its implications in cancer metastasis and treatment are also discussed.

Non-Coding RNAs as Biomarkers of Tumor Progression and Metastatic Spread in Epithelial Ovarian Cancer

Simple Summary

Despite advances in cancer research in recent years, efficient predictive biomarkers of tumor progression and metastatic spread for ovarian cancer are still missing. Therefore, we critically address recent findings in the field of non-coding RNAs (microRNAs and long non-coding RNAs) and DNA methylation in ovarian cancer patients as promising novel biomarkers of ovarian cancer progression.

Abstract

Ovarian cancer is one of the most common causes of death among gynecological malignancies. Molecular changes occurring in the primary tumor lead to metastatic spread into the peritoneum and the formation of distant metastases. Identification of these changes helps to reveal the nature of metastases development and decipher early biomarkers of prognosis and disease progression. Comparing differences in gene expression profiles between primary tumors and metastases, together with disclosing their epigenetic regulation, provides interesting associations with progression and metastasizing. Regulatory elements from the non-coding RNA families such as microRNAs and long non-coding RNAs seem to participate in these processes and represent potential molecular biomarkers of patient prognosis. Progress in therapy individualization and its proper targeting also rely upon a better understanding of interactions among the above-listed factors. This review aims to summarize currently available findings of microRNAs and long non-coding RNAs linked with tumor progression and metastatic process in ovarian cancer. These biomolecules provide promising tools for monitoring the patient’s response to treatment, and further they serve as potential therapeutic targets of this deadly disease.

RGD-Binding Integrins Revisited: How Recently Discovered Functions and Novel Synthetic Ligands (Re-)Shape an Ever-Evolving Field

Integrins have been extensively investigated as therapeutic targets over the last decades, which has been inspired by their multiple functions in cancer progression, metastasis, and angiogenesis as well as a continuously expanding number of other diseases, e.g., sepsis, fibrosis, and viral infections, possibly also Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2). Although integrin-targeted (cancer) therapy trials did not meet the high expectations yet, integrins are still valid and promising targets due to their elevated expression and surface accessibility on diseased cells. Thus, for the future successful clinical translation of integrin-targeted compounds, revisited and innovative treatment strategies have to be explored based on accumulated knowledge of integrin biology. For this, refined approaches are demanded aiming at alternative and improved preclinical models, optimized selectivity and pharmacological properties of integrin ligands, as well as more sophisticated treatment protocols considering dose fine-tuning of compounds. Moreover, integrin ligands exert high accuracy in disease monitoring as diagnostic molecular imaging tools, enabling patient selection for individualized integrin-targeted therapy. The present review comprehensively analyzes the state-of-the-art knowledge on the roles of RGD-binding integrin subtypes in cancer and non-cancerous diseases and outlines the latest achievements in the design and development of synthetic ligands and their application in biomedical, translational, and molecular imaging approaches. Indeed, substantial progress has already been made, including advanced ligand designs, numerous elaborated pre-clinical and first-in-human studies, while the discovery of novel applications for integrin ligands remains to be explored.

Wnt5A modulates integrin expression in a receptor-dependent manner in ovarian cancer cells

Wnt5A signals through various receptors that confer versatile biological functions. Here, we used Wnt5A overexpressing human ovarian SKOV-3 and OVCAR-3 stable clones for assessing integrin expression, cell proliferation, migration, invasion, and the ability of multicellular aggregates (MCAs) formation. We found here, that Wnt5A regulates differently the expression of its receptors in the stable Wnt5A overexpressing clones. The expression levels of Frizzled (FZD)-2 and -5, were increased in different clones. However ROR-1, -2 expression levels were differently regulated in clones. Wnt5A overexpressing clones showed increased cell proliferation, migration, and clonogenicity. Moreover, Wnt5A overexpressing SKOV-3 clone showed increased MCAs formation ability. Cell invasion had been increased in OVCAR-3-derived clones, while this was decreased in SKOV-3-derived clone. Importantly, αv integrin expression levels were increased in all assessed clones, accompanied by increased cell attachment to fibronectin and focal adhesion kinase activity. Moreover, the treatment of clones with Box5 as a Wnt5A/FZD5 antagonist abrogates ITGAV increase, cell proliferation, migration, and their attachment to fibronectin. Accordingly, we observed significantly higher expression levels of ITGAV and ITGB3 in human high-grade serous ovarian cancer specimens and ITGAV correlated positively with Wnt5A in metastatic serous type ovarian cancer. In summary, we hypothesize here, that Wnt5A/FZD-5 signaling modulate αv integrin expression levels that could be associated with ovarian cancer cell proliferation, migration, and fibronectin attachment.

ITGA5 is a prognostic biomarker and correlated with immune infiltration in gastrointestinal tumors

BACKGROUND

Integrin Subunit Alpha 5 (ITGA5), belongs to the integrin alpha chain family, is vital for promoting cancer cell invasion, metastasis. However, the correlation between ITGA5 expression and immune infiltration in gastrointestinal tumors remain unclear.

METHODS

The expression level of ITGA5 was detected by Oncomine and Tumor Immune Estimation Resource (TIMER). The association between ITGA5 and prognosis of patients was identified by Kaplan-Meier plotter, Gene Expression Profiling Interactive Analysis 2 (GEPIA2) and PrognoScan. We evaluated the correlation between ITGA5 expression and immune infiltrating level via TIMER. Besides, TIMER, immunohistochemistry (IHC) staining and western blot were used to explore correlations between ITGA5 expression and markers of immune infiltrates cells. Furthermore, we constructed protein-protein interaction (PPI) network and performed functional enrichment by GeneMANIA and Metascape.

RESULTS

ITGA5 was generally overexpressed and correlated with worse prognosis in multiple types of gastrointestinal tumors. In addition, ITGA5 expression level was significantly associated with tumor purity and immune infiltration levels of different immune cells in gastrointestinal tumors. Interestingly, immune markers for monocytes, tumor - associated macrophages (TAMs), macrophages 2 (M2) cells and T-helper 2 (Th2) cells were found to be significantly and positively correlated with ITGA5 expression levels in colon and gastric cancer. Results from IHC staining and western blot further proved that markers of Th2 and M2 cell were significantly increased in gastric cancer patients with high ITGA5 expression levels. Lastly, interaction network and function enrichment analysis revealed ITGA5 was mainly involved in "integrin mediated signaling pathway", "leukocyte migration", "cell-substrate adhesion".

CONCLUTIONS

Our study demonstrated that ITGA5 may act as an essential regulator of tumor immune cell infiltration and a valuable prognostic biomarker in gastrointestinal tumors. Additional work is needed to fully elucidate the underlying mechanisms behind these observations.

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.

Mixtures of persistent organic pollutants increase ovarian granulosa tumor cell line migration and spheroid invasion by upregulating MMP2 expression and activity via IGF1R

Granulosa cell tumors (GCT) of the ovary have a good prognosis. Recurrence tends to be late; however, > 66 % of patients with recurrent GCT die from the disease. Most recurrences are abdominopelvic, although distant metastases have been documented. Here, we tested the hypothesis that a mixture of persistent endocrine-disrupting chemicals (EDCs) stimulates the invasion of GCT cells. We selected perfluorooctanoate (PFOA, 2 ng/mL), perfluorooctanesulfonate (PFOS, 8 ng/mL), 2,2-dichlorodiphenyldichloroethylene (p,p'-DDE, 1 ng/mL), polychlorinated biphenyl 153 (PCB153, 100 pg/mL), and hexachlorobenzene (HCB, 50 pg/mL), which have the highest measured concentrations in follicular fluid of women undergoing treatment with assisted reproductive technology. The human GCT cell lines COV434 and KGN have been used as in vitro models of juvenile (JGCT) and adult (AGCT) GCT subtypes, respectively. Cells were treated with a mixture of the test compounds for 15 min prior to analysis of protein phosphorylation; for 4 h prior to analysis in a circular chemorepellent-induced defect assay; for 6 h prior to analysis of matrix metalloproteinase 2 (MMP2) activity; for 24 h prior to analysis of migration, invasion, and gene expression; and for 48 h prior to analysis of protein expression. First, we showed that KGN cells migrated and exhibited invasive behavior. By contrast, COV434 cells lacked migration and invasion potential. Moreover, expression of mesenchymal genes and the gene encoding MMP2 was higher in KGN cells, and that of epithelial genes lower, than that in COV434 cells. Treatment of KGN cells with the EDC mixture stimulated cell migration, invasion, and lymphatic dissemination. The results suggest that the role of the EDC mixture in AGCT invasion is not related to changes in expression of epithelial and mesenchymal genes; rather, it is related to increased expression and activity of MMP2. Additionally, silencing insulin-like growth factor 1 (IGF1R) in AGCT abolished the stimulatory effect of the EDC mixture on KGN spheroid invasion. These results demonstrate that the EDC mixture increased KGN spheroid invasion by stimulating expression and activity of MMP2 via IGF1R.