Sprouty2 inhibits amphiregulin-induced down-regulation of E-cadherin and cell invasion in human ovarian cancer cells

Amphiregulin Downregulates E-cadherin Expression by Activating YAP/Egr-1/Slug Signaling in SKOV3 Human Ovarian Cancer Cells

Amphiregulin (AREG) stimulates human epithelial ovarian cancer (EOC) cell invasion by downregulating E-cadherin expression. YAP is a transcriptional cofactor that has been shown to regulate tumorigenesis. This study aimed to examine whether AREG activates YAP in EOC cells and explore the roles of YAP in AREG-induced downregulation of E-cadherin and cell invasion. Analysis of the Cancer Genome Atlas (TCGA) showed that upregulation of AREG and EGFR were associated with poor survival in human EOC. Treatment of SKOV3 human EOC cells with AREG induced the activation of YAP. In addition, AREG downregulated E-cadherin, upregulated Egr-1 and Slug, and stimulated cell invasion. Using gain- and loss-of-function approaches, we showed that YAP was required for the AREG-upregulated Egr-1 and Slug expression. Furthermore, YAP was also involved in AREG-induced downregulation of E-cadherin and cell invasion. This study provides evidence that AREG stimulates human EOC cell invasion by downregulating E-cadherin expression through the YAP/Egr-1/Slug signaling.

Enhanced amphiregulin exposure promotes modulation of the high grade serous ovarian cancer tumor immune microenvironment

High grade serous ovarian cancer (HGSOC) is a lethal gynecologic malignancy in which chemoresistant recurrence rates remain high. Furthermore, HGSOC patients have demonstrated overall low response rates to clinically available immunotherapies. Amphiregulin (AREG), a low affinity epidermal growth factor receptor ligand is known to be significantly upregulated in HGSOC patient tumors following neoadjuvant chemotherapy exposure. While much is known about AREG's role in oncogenesis and classical immunity, it is function in tumor immunology has been comparatively understudied. Therefore, the objective of this present study was to elucidate how increased AREG exposure impacts the ovarian tumor immune microenvironment (OTIME). Using NanoString IO 360 and protein analysis, it was revealed that treatment with recombinant AREG led to prominent upregulation of genes associated with ovarian pathogenesis and immune evasion (CXCL8, CXCL1, CXCL2) along with increased STAT3 activation in HGSOC cells. In vitro co-culture assays consisting of HGSOC cells and peripheral blood mononuclear cells (PBMCs) stimulated with recombinant AREG (rAREG) led to significantly enhanced tumor cell viability. Moreover, PBMCs stimulated with rAREG exhibited significantly lower levels of IFNy and IL-2. In vivo rAREG treatment promoted significant reductions in circulating levels of IL-2 and IL-5. Intratumoral analysis of rAREG treated mice revealed a significant reduction in CD8+ T cells coupled with an upregulation of PD-L1. Finally, combinatorial treatment with an AREG neutralizing antibody and carboplatin led to a synergistic reduction of cell viability in HGSOC cell lines OVCAR8 and PEA2. Overall, this study demonstrates AREG's ability to modulate cytotoxic responses within the OTIME and highlights its role as a novel HGSOC immune target.

The role of amphiregulin in ovarian function and disease

Amphiregulin (AREG) is an epidermal growth factor (EGF)-like growth factor that binds exclusively to the EGF receptor (EGFR). Treatment with luteinizing hormone (LH) and/or human chorionic gonadotropin dramatically induces the expression of AREG in the granulosa cells of the preovulatory follicle. In addition, AREG is the most abundant EGFR ligand in human follicular fluid. Therefore, AREG is considered a predominant propagator that mediates LH surge-regulated ovarian functions in an autocrine and/or paracrine manner. In addition to the well-characterized stimulatory effect of LH on AREG expression, recent studies discovered that several local factors and epigenetic modifications participate in the regulation of ovarian AREG expression. Moreover, aberrant expression of AREG has recently been reported to contribute to the pathogenesis of several ovarian diseases, such as ovarian hyperstimulation syndrome, polycystic ovary syndrome, and epithelial ovarian cancer. Furthermore, increasing evidence has elucidated new applications of AREG in assisted reproductive technology. Collectively, these studies highlight the importance of AREG in female reproductive health and disease. Understanding the normal and pathological roles of AREG and elucidating the molecular and cellular mechanisms of AREG regulation of ovarian functions will inform innovative approaches for fertility regulation and the prevention and treatment of ovarian diseases. Therefore, this review summarizes the functional roles of AREG in ovarian function and disease.

Adaptive transcriptomic and immune infiltrate responses in the tumor immune microenvironment following neoadjuvant chemotherapy in high grade serous ovarian cancer reveal novel prognostic associations and activation of pro-tumorigenic pathways

The high rate of ovarian cancer recurrence and chemoresistance necessitates further research into how chemotherapy affects the tumor immune microenvironment (TIME). While studies have shown that immune infiltrate increases following neoadjuvant (NACT) chemotherapy, there lacks a comprehensive understanding of chemotherapy-induced effects on immunotranscriptomics and cancer-related pathways and their relationship with immune infiltrate and patient responses. In this study, we performed NanoString nCounter^® PanCancer IO360 analysis of 31 high grade serous ovarian cancer (HGSOC) patients with matched pre-treatment biopsy and post-NACT tumor. We observed increases in pro-tumorigenic and immunoregulatory pathways and immune infiltrate following NACT, with striking increases in a cohort of genes centered on the transcription factors ATF3 and EGR1. Using quantitative PCR, we analyzed several of the top upregulated genes in HGSOC cell lines, noting that two of them, ATF3 and AREG, were consistently upregulated with chemotherapy exposure and significantly increased in platinum resistant cells compared to their sensitive counterparts. Furthermore, we observed that pre-NACT immune infiltrate and pathway scores were not strikingly related to platinum free interval (PFI), but post-NACT immune infiltrate, pathway scores, and gene expression were. Finally, we found that higher levels of a cohort of proliferative and DNA damage-related genes was related to shorter PFI. This study underscores the complex alterations in the ovarian TIME following chemotherapy exposure and begins to untangle how immunologic factors are involved in mediating chemotherapy response, which will allow for the future development of novel immunologic therapies to combat chemoresistance.

Pharmacological inhibition of 17β-hydroxysteroid dehydrogenase impairs human endometrial cancer growth in an orthotopic xenograft mouse model

Endometrial cancer (EC) is the most common gynaecological tumor in developed countries and its incidence is increasing. Approximately 80% of newly diagnosed EC cases are estrogen-dependent. Type 1 17β-hydroxysteroid dehydrogenase (17β-HSD-1) is the enzyme that catalyzes the final step in estrogen biosynthesis by reducing the weak estrogen estrone (E1) to the potent estrogen 17β-estradiol (E2), and previous studies showed that this enzyme is implicated in the intratumoral E2 generation in EC. In the present study we employed a recently developed orthotopic and estrogen-dependent xenograft mouse model of EC to show that pharmacological inhibition of the 17β-HSD-1 enzyme inhibits disease development. Tumors were induced in one uterine horn of athymic nude mice by intrauterine injection of the well-differentiated human endometrial adenocarcinoma Ishikawa cell line, modified to express human 17β-HSD-1 in levels comparable to EC, and the luciferase and green fluorescent protein reporter genes. Controlled estrogen exposure in ovariectomized mice was achieved using subcutaneous MedRod implants that released either the low active estrone (E1) precursor or vehicle. A subgroup of E1 supplemented mice received daily oral gavage of FP4643, a well-characterized 17β-HSD-1 inhibitor. Bioluminescence imaging (BLI) was used to measure tumor growth non-invasively. At sacrifice, mice receiving E1 and treated with the FP4643 inhibitor showed a significant reduction in tumor growth by approximately 65% compared to mice receiving E1. Tumors exhibited metastatic spread to the peritoneum, to the lymphovascular space (LVI), and to the thoracic cavity. Metastatic spread and LVI invasion were both significantly reduced in the inhibitor-treated group. Transcriptional profiling of tumors indicated that FP4643 treatment reduced the oncogenic potential at the mRNA level. In conclusion, we show that 17β-HSD-1 inhibition represents a promising novel endocrine treatment for EC.

Unraveling the Catha edulis Extract Effects on the Cellular and Molecular Signaling in SKOV3 Cells

Khat (Catha edulis (Vahl) Endl.) is an evergreen flowering shrub used as a stimulant in many regions worldwide including East Africa, the Arabian Peninsula, Europe, and the United States. Chewing leaves of khat induces excitement and euphoria, which are primarily attributed to two major constituents, cathinone and cathine. Khat also contains other important constituents such as cathedulins. A considerable number of studies reported side effects induced by the khat extracts to both embryos and adults. These include teratogenicity and developmental retardation, oral cancer and ulcers, high blood pressure, and myocardial infarction. So far, little attention has been paid to the effects of khat extracts on the molecular signaling interactions. We aimed in this study to investigate this through evaluating the effects of khat extracts on SKOV3, a human ovarian adenocarcinoma cell line. We show, by in vitro assays, that khat induces several cellular defects including reduced cell size, cell membrane damage, and apoptosis. At high khat extract concentrations, the cell metabolic activity, cell cycle, and cellular proliferation were affected. RT-qPCR analysis showed an increase in the gene expression of the apoptotic marker BAX, the tumor suppressor p53, and the inflammatory cytokine IL-6. Protein expression analysis by immunostaining showed downregulation of β-catenin, E-cadherin, and Ki-67 and upregulation of FZD8 and SPRY2, suggesting that Wnt and FGF signaling were implicated. SwissTargetPrediction in silico analysis showed that khat constituents cathine, cathinone, catheduline K2, and catheduline E5 bind to family A G-protein-coupled receptor, cause many neurological diseases and disorders such as Alzheimer's, schizophrenia, depression, and anxiety, and induce many ovarian cancer-related diseases. The analysis also showed that important signaling pathways such as CREB, Wnt, FGF, IL-6, and ERK/MAPK, and that of the endometrial cancer, and cell cycle were implicated. Upstream regulators of cathine and cathinone were found to potentially target several molecules including interleukin-8, MMP2, PLAU, and micro-RNAs. In conclusion, khat induces significant cellular and molecular changes that could potentially cause a wide range of serious diseases and syndromes. Such an impact could have a heavy burden on the health care system in the countries where khat is consumed.

ADAM17 Inhibition Increases the Impact of Cisplatin Treatment in Ovarian Cancer Spheroids

Simple Summary

Ovarian cancer (OvCa) treatment is still a challenge, mainly due to acquired resistance mechanisms during the course of chemotherapy. Here, we show the enhanced cytotoxicity of the combined treatment with the ADAM17 inhibitor GW280264X and cisplatin in comparison with cisplatin monotherapy. This effect was visible in five of five ovarian cancer cell lines grown as a monolayer and two of three tested cell lines in three-dimensional tumor spheroids. Tumor spheroids derived from primary tumor and ascites cells were sensitized to cisplatin treatment by GW280264X. In summary, the combination of ADAM17 inhibition with conventional chemotherapy seems to be a promising strategy to overcome chemotherapy resistance in OvCa.

Abstract

Chemotherapy resistance is a major challenge in ovarian cancer (OvCa). Thus, novel treatment combinations are highly warranted. However, many promising drug candidates tested in two-dimensional (2D) cell culture have not proved successful in the clinic. For this reason, we analyzed our drug combination not only in monolayers but also in three-dimensional (3D) tumor spheroids. One potential therapeutic target for OvCa is A disintegrin and metalloprotease 17 (ADAM17). ADAM17 can be activated by chemotherapeutics, which leads to enhanced tumor growth due to concomitant substrate cleavage. Therefore, blocking ADAM17 during chemotherapy may overcome resistance. Here, we tested the effect of the ADAM17 inhibitor GW280264X in combination with cisplatin on ovarian cancer cells in 2D and 3D. In 2D, the effect on five cell lines was analyzed with two readouts. Three of these cell lines formed dense aggregates or spheroids (HEY, SKOV-3, and OVCAR-8) in 3D and the treatment effect was analyzed with a multicontent readout (cytotoxicity, viability, and caspase3/7 activation). We tested the combined therapy on tumor spheroids derived from primary patient cells. In 2D, we found a significant reduction in the half minimal (50%) inhibitory concentration (IC₅₀) value of the combined treatment (GW280264X plus cisplatin) in comparison with cisplatin monotherapy in all five cell lines with both 2D readout assays (viability and caspase activation). In contrast, the combined treatment only showed an IC₅₀ reduction in HEY and OVCAR-8 3D tumor spheroid models using caspase3/7 activity or Celltox^TM Green as the readout. Finally, we found an improved effect of GW280264X with cisplatin in tumor spheroids derived from patient samples. In summary, we demonstrate that ADAM17 inhibition is a promising treatment strategy in ovarian cancer.

Development of a 3D functional assay and identification of biomarkers, predictive for response of high-grade serous ovarian cancer (HGSOC) patients to poly-ADP ribose polymerase inhibitors (PARPis): targeted therapy

Background

Poly(ADP-ribose) polymerase inhibitors (PARPis) specifically target homologous recombination deficiency (HRD) cells and display good therapeutic effect in women with advanced-stage BRCA1/2-mutated breast and epithelial ovarian cancer (EOC). However, about 50% of high grade serous ovarian cancers (HGSOC) present with HRD due to epigenetic BRCA1 inactivation, as well as genetic/epigenetic inactivation(s) of other HR genes, a feature known as “BRCAness”. Therefore, there is a potential for extending the use of PARPis to these patients if HR status can be identified.

Methods

We have developed a 3D (spheroid) functional assay to assess the sensitivity of two PARPis (niraparib and olaparib) in ascites-derived primary cell cultures (AsPCs) from HGSOC patients. A method for AsPCs preparation was established based on a matrix (agarose), allowing for easy isolation and successive propagation of monolayer and 3D AsPCs. Based on this method, we performed cytotoxicity assays on 42 AsPCs grown both as monolayers and spheroids.

Results

The response to PARPis treatment in monolayer AsPCs, was significantly higher, compared to 3D AsPCs, as 88% and 52% of the monolayer AsPCs displayed sensitivity to niraparib and olaparib respectively, while 66% of the 3D AsPCs were sensitive to niraparib and 38% to olaparib, the latter being more consistent with previous estimates of HRD (40%–60%) in EOC. Moreover, niraparib displayed a significantly stronger cytotoxic effect in both in 3D and monolayer AsPCs, which was confirmed by consecutive analyses of the HR pathway activity (γH2AX foci formation) in PARPis-sensitive and resistant AsPCs. Global gene expression comparison of 6 PARPi-resistant and 6 PARPi-sensitive 3D AsPCs was indicative for the predominant downregulation of numerous genes and networks with previously demonstrated roles in EOC chemoresistance, suggesting that the PARPis-sensitive AsPCs could display enhanced sensitivity to other chemotherapeutic drugs, commonly applied in cancer management. Microarray data validation identified 24 potential gene biomarkers associated with PARPis sensitivity. The differential expression of 7 selected biomarkers was consecutively confirmed by immunohistochemistry in matched EOC tumor samples.

Conclusion

The application of this assay and the potential biomarkers with possible predictive significance to PARPis therapy of EOC patients now need testing in the setting of a clinical trial.

Liriopesides B from Liriope spicata var. prolifera inhibits metastasis and induces apoptosis in A2780 human ovarian cancer cells

Ovarian cancer is the most frequent cause of death among gynecological cancers. In the present study, the anti-cancer effect of liriopesides B, a steroidal saponin from Liriope spicata var. prolifera, against A2780 cells was investigated. Transwell chambers were adopted to assess its effect on cell invasion and chemotaxis abilities. Flow cytometry was used to analyze the cell cycle and apoptosis. Reverse transcription-quantitative PCR was employed to examine gene expression levels. Western blot analysis was performed to detect protein expression levels. Liriopesides B inhibited the invasion and chemotactic movement ability of A2780 cells in a dose-dependent manner. Furthermore, liriopesides B caused cell cycle arrest in A2780 cells at the G1 phase following incubation for 24, 48 and 72 h. Hoechst 33258 staining indicated that, following incubation for 48 h, liriopesides B induced cell apoptosis in a dose-dependent manner. Flow cytometry verified that liriopesides B induced apoptosis in A2780 cells and induced late apoptosis in a dose-dependent manner. Furthermore, liriopesides B significantly increased the mRNA expression levels of E-CADHERIN, p21 and p27 and decreased the gene expression levels of BCL-2, which was consistent with its protein expression levels. In conclusion, liriopesides B possess anti-cancer properties, including inhibition of metastasis-associated behaviors, cell cycle arrest and induction of apoptosis. Therefore, liriopesides B may be considered as a candidate drug against ovarian cancer.

Prediction of blood-based biomarkers and subsequent design of bisulfite PCR-LDR-qPCR assay for breast cancer detection

Background

Interrogation of site-specific CpG methylation in circulating tumor DNAs (ctDNAs) has been employed in a number of studies for early detection of breast cancer (BrCa). In many of these studies, the markers were identified based on known biology of BrCa progression, and interrogated using methyl-specific PCR (MSP), a technique involving bisulfite conversion, PCR, and qPCR.

Methods

In this report, we are demonstrating the development of a novel assay (Multiplex Bisulfite PCR-LDR-qPCR) which can potentially offer improvements to MSP, by integrating additional steps such as ligase detection reaction (LDR), methylated CpG target enrichment, carryover protection (use of uracil DNA glycosylase), and minimization of primer-dimer formation (use of ribose primers and RNAseH2). The assay is designed to for breast cancer-specific CpG markers identified through integrated analyses of publicly available genome-wide methylation datasets for 31 types of primary tumors (including BrCa), as well as matching normal tissues, and peripheral blood.

Results

Our results indicate that the PCR-LDR-qPCR assay is capable of detecting ~ 30 methylated copies of each of 3 BrCa-specific CpG markers, when mixed with excess amount unmethylated CpG markers (~ 3000 copies each), which is a reasonable approximation of BrCa ctDNA overwhelmed with peripheral blood cell-free DNA (cfDNA) when isolated from patient plasma. The bioinformatically-identified CpG markers are located in promoter regions of NR5A2 and PRKCB, and a non-coding region of chromosome 1 (upstream of EFNA3). Additional bioinformatic analyses would reveal that these methylation markers are independent of patient race and age, and positively associated with signaling pathways associated with BrCa progression (such as those related to retinoid nuclear receptor, PTEN, p53, pRB, and p27).

Conclusion

This report demonstrates the potential utilization of bisulfite PCR-LDR-qPCR assay, along with bioinformatically-driven biomarker discovery, in blood-based BrCa detection.

LncRNA CASC9 Affects Cell Proliferation, Migration, and Invasion of Tongue Squamous cell Carcinoma via Regulating miR-423-5p/SOX12 Axes

Introduction

The incidence of tongue squamous cell carcinoma (TSCC) has increased in recent decades. However, the function of long non-coding RNA (lncRNA) CASC9 in the occurrence and progression of TSCC is unclear. In this work, we attempted to clarify the role of lncRNA CASC9 in determining the phenotype of TSCC cells, and to clarify the underlying mechanisms.

Methods

We used qRT-PCR analysis to identify the level of CASC9 mRNA expression in TSCC clinical samples and cell lines. We investigated cell proliferation, and cell migration and invasion of TSCC cells transfected with siCASC9 or siNC using CCK-8 and transwell assays. Bioinformatics analysis and a luciferase reporter assay were employed to predict and verify the target microRNA (miRNA).

Results

CASC9 was up-regulated in the TSCC tissues and cells, and predicted a poor prognosis. CASC9 silencing significantly inhibited cell proliferation, migration, and invasion of the TSCC cells compared with the non-targeting control small interfering RNA (siCtrl) treatment. miR-423-5p was predicted as the targeting miRNA of CASC9; this was verified by a luciferase reporter assay. CASC9 expression showed a negative correlation with miR-423-5p expression and a positive correlation with SOX12 expression. The miR-423-5p inhibitor can rescue the carcinogenesis effect of CASC9 on TSCC cells.

Conclusion

Our work indicates that CASC9 plays a role in TSCC tumorigenesis; this novel information will improve TSCC molecular targeting therapy.

miR-200c overexpression inhibits the invasion and tumorigenicity of epithelial ovarian cancer cells by suppressing lncRNA HOTAIR in mice

Epithelial ovarian cancer (EOC) is a common ovarian cancer in gynecological cancers today. It has been found that microRNAs and long-chain noncoding RNA (lncRNA) regulate the gene transcriptional expression in cells. However, it is not well understood that the upstream and downstream regulatory molecules of lncRNA HOX antisense intergenic RNA (HOTAIR). The effects of miR-200c overexpression on the invasion and nude mouse tumorigenicity, as well as lncRNA HOTAIR and snail expression of EOC SKOV3 cells, should be further explored. The expression of miR-200c and lncRNA HOTAIR was detected by reverse transcription PCR (RT-PCR) in EOC SKOV3 cells. The whole miR-200c gene fragment was cloned into a lentiviral plasmid vector. The miR-200c expression in transducted SKOV3 cells with reconstructed miR-200c lentivirus was significantly higher than the negative control (P < .01). The lentivirus-miR-200c-SKOV3 cells show that the invasion ability was significantly decreased compared with the negative control (P < .01). The nude mouse tumorigenicity was significantly decreased compared with that of the control group (P < .01). The snail protein expression in lentivirus-miR-200c-SKOV3 xenograft tumor was significantly decreased compared with the negative control lentivirus-SKOV3 group (P < .05). The miR-200c overexpression significantly decreased the expressions of lncRNA HOTAIR and snail, but increased E-cadherin expression in the lentivirus-miR-200c transducted SKOV3 cells of xenograft tumor, compared with the negative control (P < .05). The miR-200c overexpression in SKOV3 cells with transducted lentivirus-miR-200c can inhibit lncRNA HOTAIR expression, decrease snail, increase E-cadherin and significantly reduce the invasion and tumorigenicity of EOC SKOV3 cells. These results suggest that the miR-200c and lncRNA HOTAIR could be effective therapeutic targets for human epithelial ovarian cancer treatment.

Ribophorin II promotes cell proliferation, migration, and invasion in esophageal cancer cells in vitro and in vivo

Esophageal cancer is a common digestive tract cancer, which is a serious threat to human health. Ribophorin II (RPN2) is a part of an N-oligosaccharyltransferase complex, which is excessively expressed in many kinds of cancers. In the present study, we explore the biological role of RNP2 in esophageal cancer. First, we found that the expression of RPN2 was higher in esophageal cancer tissues than in adjacent non-tumor tissues, and negatively correlated with E-cadherin expression. RPN2 expression levels in esophageal cancer tissues were positively associated with differentiation and tumor node metastasis (TNM) stage. Furthermore, the expression of RPN2 was increased significantly in esophageal cancer cell lines compared with normal cells. The effect of RPN2 down-regulation on cell proliferation, cell migration, and cell invasion was examined by cell counting kit-8 (CCK8), wound healing assay, and Transwell assay, respectively. Silencing RPN2 effectively inhibited cell proliferation of esophageal cancer cells in vitro and in vivo Cell migration and invasion were also weakened dramatically by siRPN2 treatment of esophageal cancer cells. In addition, protein expression of proliferating cell nuclear antigen (PCNA), matrix metalloproteinase (MMP-2), and E-cadherin in esophageal cancer cells was determined by Western blot analysis. PCNA, MMP-2, E-cadherin, Snail and phosphorylation-Smad2/3 expression was also regulated notably by siRPN2 treatment. These findings indicate that RPN2 exhibits oncogenetic capabilities in esophageal cancer, which could provide novel insights into esophageal cancer prevention and treatment.

Downregulation of ribophorin II suppresses tumor growth, migration, and invasion of nasopharyngeal carcinoma

Background

It has been reported that ribophorin II (RPN2) expression is increased in many cancers, but the role of RPN2 in nasopharyngeal carcinoma (NPC) remains unclear.

Patients and methods

This study found that the expression of RPN2 is increased dramatically in NPC tissues of patients compared with that in the adjacent normal tissues. This study attempted at understanding the effect of siRNA-RPN2 treatment on the migration and invasion of NPC cell lines CNE2 and HNE1.

Results

RT-PCR and Western blotting showed that RPN2 was highly expressed in CNE2 and HNE1 cells. siRNA-RPN2 treatment significantly inhibited cell viability at 24 and 48 h compared with the control group. Results of the transwell assay showed that, compared to the control groups, migration and invasion of the cells treated with siRNA-RPN2 decreased markedly. In addition, compared to the control groups, caspase-3, caspase-9, and E-cadherin expression levels increased and MMP 2 expression decreased significantly in the siRNA-RPN2-treated group. Phosphorylation of AKT and PI3K was also inhibited after siRNA-RPN2 treatment.

Conclusion

siRNA-RPN2 can effectively inhibit the invasion and migration of human NPC cells via AKT/PI3K signaling. This can serve as a novel strategy for NPC treatment.