A VEGF-dependent gene signature enriched in mesenchymal ovarian cancer predicts patient prognosis

Histopathological subtyping of high-grade serous ovarian cancer using whole slide imaging

OBJECTIVE

We have established 4 histopathologic subtyping of high-grade serous ovarian cancer (HGSOC) and reported that the mesenchymal transition (MT) type has a worse prognosis than the other subtypes. In this study, we modified the histopathologic subtyping algorithm to achieve high interobserver agreement in whole slide imaging (WSI) and to characterize the tumor biology of MT type for treatment individualization.

METHODS

Four observers performed histopathological subtyping using WSI of HGSOC in The Cancer Genome Atlas data. As a validation set, cases from Kindai and Kyoto Universities were independently evaluated by the 4 observers to determine concordance rates. In addition, genes highly expressed in MT type were examined by gene ontology term analysis. Immunohistochemistry was also performed to validate the pathway analysis.

RESULTS

After algorithm modification, the kappa coefficient, which indicates interobserver agreement, was greater than 0.5 (moderate agreement) for the 4 classifications and greater than 0.7 (substantial agreement) for the 2 classifications (MT vs. non-MT). Gene expression analysis showed that gene ontology terms related to angiogenesis and immune response were enriched in the genes highly expressed in the MT type. CD31 positive microvessel density was higher in the MT type compared to the non-MT type, and tumor groups with high infiltration of CD8/CD103 positive immune cells were observed in the MT type.

CONCLUSION

We developed an algorithm for reproducible histopathologic subtyping classification of HGSOC using WSI. The results of this study may be useful for treatment individualization of HGSOC, including angiogenesis inhibitors and immunotherapy.

Circulating Angiogenic Markers in Gastroenteropancreatic Neuroendocrine Neoplasms: A Systematic Review

Background: Neuroendocrine neoplasms are a heterogeneous group of tumors that raise challenges in terms of diagnosis, treatment and monitoring. Despite continuous efforts, no biomarker has showed satisfying accuracy in predicting outcome or response to treatment. Methods: We conducted a systematic review to determine relevant circulating biomarkers for angiogenesis in neuroendocrine tumors. We searched three databases (Pubmed, Embase, Web of Science) using the keywords “neuroendocrine” and “biomarkers”, plus specific biomarkers were searched by full and abbreviated name. From a total of 2448 publications, 11 articles met the eligibility criteria. Results: VEGF is the most potent and the most studied angiogenic molecule, but results were highly controversial. Placental growth factor, Angiopoietin 2 and IL-8 were the most consistent markers in predicting poor outcome and aggressive disease behavior. Conclusions: There is no robust evidence so far to sustain the use of angiogenic biomarkers in routine practice, although the results show promising leads.

Identification of GNA12-driven gene signatures and key signaling networks in ovarian cancer

With the focus on defining the oncogenic network stimulated by lysophosphatidic acid (LPA) in ovarian cancer, the present study sought to interrogate the oncotranscriptome regulated by the LPA-mediated signaling pathway. LPA, LPA-receptor (LPAR) and LPAR-activated G protein 12 α-subunit, encoded by G protein subunit α 12 (GNA12), all serve an important role in ovarian cancer progression. While the general signaling mechanism regulated by LPA/LPAR/GNA12 has previously been characterized, the global transcriptomic network regulated by GNA12 in ovarian cancer pathophysiology remains largely unknown. To define the LPA/LPAR/GNA12-orchestrated oncogenic networks in ovarian cancer, transcriptomic and bioinformatical analyses were conducted using SKOV3 cells, in which the expression of GNA12 was silenced. Array analysis was performed in Agilent SurePrint G3 Human Comparative Genomic Hybridization 8×60 microarray platform. The array results were validated using Kuramochi cells. Gene and functional enrichment analyses were performed using Database for Annotation, Visualization and Integrated Discovery, Search Tool for Retrieval of Interacting Genes and Cytoscape algorithms. The results indicated a paradigm in which GNA12 drove ovarian cancer progression by upregulating a pro-tumorigenic network with AKT1, VEGFA, TGFB1, BCL2L1, STAT3, insulin-like growth factor 1 and growth hormone releasing hormone as critical hub and/or bottleneck nodes. Moreover, GNA12 downregulated a growth-suppressive network involving proteasome 20S subunit (PSM) β6, PSM α6, PSM ATPase 5, ubiquitin conjugating enzyme E2 E1, PSM non-ATPase 10, NDUFA4 mitochondrial complex-associated, NADH:ubiquinone oxidoreductase subunit B8 and anaphase promoting complex subunit 1 as hub or bottleneck nodes. In addition to providing novel insights into the LPA/LPAR/GNA12-regulated oncogenic networks in ovarian cancer, the present study identified several potential nodes in this network that could be assessed for targeted therapy.

Antiangiogenesis Efficacy of Ethanol Extract from Amomum tsaoko in Ovarian Cancer through Inducing ER Stress to Suppress p-STAT3/NF-kB/IL-6 and VEGF Loop

Natural plants are considered as a huge treasure for anticancer. Amomum tsaoko, a plant of Zingiberaceae, is used widely as a food and traditional medicine in East Asia. In previous studies, Amomum tsaoko has antitumor effect on liver cancer cells, but the mechanism is not clear. Here, we demonstrated that ethanol extract from Amomum tsaoko (At-EE) could inhibit ovarian cancer and decrease angiogenesis in vivo. At-EE did not influence vascular endothelial cells directly, but decreased IL-6 and VEGF secreted by ovarian cancer cells to inhibit angiogenesis through inhibition of p-STAT3 and NF-kB activation. In addition, we demonstrated that p-STAT3 and NF-kB could adjust each other and IL-6 and VEGF also mediate p-STAT3 and NF-kB too, which created a loop. In addition, At-EE interrupted p-STAT3/NF-kB/IL-6 and VEGF loop through induced ER stress. These results reveal that p-STAT3/NF-kB/IL-6 and VEGF is a cascade amplification loop in ovarian cancer for angiogenesis, and induced ER stress can interrupt it. Taken together, this work explored the anticancer activities of Amomum tsaoko, which could be a potential therapeutic candidate in the treatment of ovarian cancer.

FSH receptor binding inhibitor depresses carcinogenesis of ovarian cancer via decreasing levels of K-Ras, c-Myc and FSHR

The present study aimed to explore FSH receptor binding inhibitor (FRBI) effects on the levels of c-Myc, K-Ras and VEGF related to ovarian cancer, to evaluate the mRNA and protein levels of FSHR in the cumulus-oocyte complex (COCs). COCs were cultured for 24 h in the in vitro maturation (IVM) media replenished with 0, 10, 20, 30 and 40 μg/mL FRBI. Contents of c-Myc, K-Ras, VEGF, cAMP and IP3 in IVM media were detected with ELISA kits, respectively. The results indicated that the levels of FSHR protein and mRNA were determined with Western blotting. C-Myc contents of four FRBI + FSH-treated groups (COM groups) were reduced after IVM of COCs. C-Myc concentrations of COM-3 group was lower than the FSH group (p < .05). K-Ras and IP3 contents of COM-4 were decreased as compared to FSH group (p < .05). Expression levels of FSHR mRNAs and proteins in COM-4 group were smaller than that of FSH group. This study revealed that FRBI treatment could decrease c-Myc and K-Ras levels in the IVM medium fluids, and depress the FSHR levels of COCs. Expression levels of FSHR mRNAs and proteins of COM-4 group were significantly decreased. FRBI exerted its action via the signal pathway of IP3 and cAMP.

PAX8 regulon in human ovarian cancer links lineage dependency with epigenetic vulnerability to HDAC inhibitors

PAX8 is a prototype lineage-survival oncogene in epithelial ovarian cancer. However, neither its underlying pro-tumorigenic mechanisms nor potential therapeutic implications have been adequately elucidated. Here, we identified an ovarian lineage-specific PAX8 regulon using modified cancer outlier profile analysis, in which PAX8-FGF18 axis was responsible for promoting cell migration in an autocrine fashion. An image-based drug screen pinpointed that PAX8 expression was potently inhibited by small-molecules against histone deacetylases (HDACs). Mechanistically, HDAC blockade altered histone H3K27 acetylation occupancies and perturbed the super-enhancer topology associated with PAX8 gene locus, resulting in epigenetic downregulation of PAX8 transcripts and related targets. HDAC antagonists efficaciously suppressed ovarian tumor growth and spreading as single agents, and exerted synergistic effects in combination with standard chemotherapy. These findings provide mechanistic and therapeutic insights for PAX8-addicted ovarian cancer. More generally, our analytic and experimental approach represents an expandible paradigm for identifying and targeting lineage-survival oncogenes in diverse human malignancies.

The mesenchymal transition subtype more responsive to dose dense taxane chemotherapy combined with carboplatin than to conventional taxane and carboplatin chemotherapy in high grade serous ovarian carcinoma: A survey of Japanese Gynecologic Oncology Group study (JGOG3016A1)

OBJECTIVE

Recently, we established new histopathological subtypes of high-grade serous ovarian cancer (HGSOC) that include the mesenchymal transition (MT) type, the immune reactive (IR) type, the solid and proliferative (SP) type and the papillo-glandular (PG) type. Furthermore, we identified that the mesenchymal transcriptome subtype might be sensitive to taxane. We investigated whether these different histopathological subtypes of HGSOC require individualized chemotherapy for optimal treatment.

METHODS

We conducted the Japanese Gynecologic Oncology Group (JGOG) 3016A1 study, wherein we collected hematoxylin and eosin slides (total n = 201) and performed a histopathological analysis of patients with HGSOC registered in the JGOG3016 study, which compared the efficacy of conventional paclitaxel and carboplatin (TC) and dose-dense TC (ddTC). We analyzed the differences in progression-free survival (PFS) and overall survival (OS) among the four histopathological subtypes. We then compared the PFS between the TC group and the ddTC group for each histopathological subtype.

RESULTS

There were significant differences in both PFS and OS among the four histopathological subtypes (p = 0.001 and p < 0.001, respectively). Overall, the MT subtype had the shortest PFS (median 1.4 y) and OS (median 3.6 y). In addition, the MT subtype had a longer PFS in the ddTC group (median 1.8 y) than in the TC group (median 1.2 y) (p = 0.01). Conversely, the other types had no significant difference in PFS when the two regimens were compared.

CONCLUSIONS

The MT type of HGSOC is sensitive to taxane; therefore, the ddTC regimen is recommended for this histopathological subtype.

Vascular endothelial growth factor receptor 2 (VEGFR2) correlates with long-term survival in patients with advanced high-grade serous ovarian cancer (HGSOC): a study from the Tumor Bank Ovarian Cancer (TOC) Consortium

OBJECTIVE

The impact of angiogenesis on long-term survival of high-grade serous ovarian cancer (HGSOC) patients remains unclear. This study investigated whether angiogenic markers correlated with 5-year progression-free survival (PFS) in a large cohort of matched advanced HGSOC tissue samples.

METHODS

Tumor samples from 124 primary HGSOC patients were retrospectively collected within the Tumor Bank Ovarian Cancer ( http://www.toc-network.de ). All patients were in advanced stages (FIGO stage III-IV). No patient had received anti-angiogenesis therapy. The cohort contains 62 long-term survivors and 62 controls matched by age and post-surgical tumor residuals. Long-term survivors were defined as patients with no relapse within 5 years after the end of first-line chemotherapy. Controls were patients who suffered from first relapse within 6-36 months after primary treatment. Samples were assessed for immunohistochemical expression of vascular endothelial growth factor (VEGF) A and VEGF receptor 2 (VEGFR2). Expression profiles of VEGFA and VEGFR2 were compared between the two groups.

RESULTS

Significant correlation between VEGFA and VEGFR2 expression was observed (p < 0.0001, Spearman coefficient 0.347). A high expression of VEGFR2 (VEGFR2^high) was found more frequently in long-term survivors (77.4%, 48/62) than in controls (51.6%, 30/62, p = 0.001), independent of FIGO stage and VEGFA expression in multivariate analysis (p = 0.005). Also, VEGFR2^high was found the most frequently in women with PFS ≥ 10 years (p = 0.001) among all 124 patients. However, no significant association was detected between VEGFA expression and 5-year PFS (p = 0.075).

CONCLUSIONS

VEGFR2 overexpression significantly correlated with long-term PFS in HGSOC patients, independent of age, FIGO stage, tumor residual and VEGFA expression.

Characterisation of tumour microvessel density during progression of high-grade serous ovarian cancer: clinico-pathological impact (an OCTIPS Consortium study)

BACKGROUND

High-grade serous ovarian cancer (HGSOC) intratumoural vasculature evolution remains unknown. The study investigated changes in tumour microvessel density (MVD) in a large cohort of paired primary and recurrent HGSOC tissue samples and its impact on patients' clinico-pathological outcome.

METHODS

A total of 222 primary (pOC) and recurrent (rOC) intra-patient paired HGSOC were assessed for immunohistochemical expression of angiogenesis-associated biomarkers (CD31, to evaluate MVD, and VEGF-A). Expression profiles were compared between pOCs and rOCs and correlated with patients' data.

RESULTS

High intratumoural MVD and VEGF-A expression were observed in 75.7% (84/111) and 20.7% (23/111) pOCs, respectively. MVD^high and VEGF⁽⁺⁾ samples were detected in 51.4% (57/111) and 20.7% (23/111) rOCs, respectively. MVD^high/VEGF⁽⁺⁾ co-expression was found in 19.8% (22/111) and 8.1% (9/111) of pOCs and rOCs, respectively (p = 0.02). Pairwise analysis showed no significant change in MVD (p = 0.935) and VEGF-A (p = 0.121) levels from pOCs to rOCs. MVD^high pOCs were associated with higher CD3⁽⁺⁾ (p = 0.029) and CD8⁽⁺⁾ (p = 0.013) intratumoural effector TILs, while VEGF⁽⁺⁾ samples were most frequently encountered among BRCA-mutated tumours (p = 0.019). Multivariate analysis showed VEGF and MVD were not independent prognostic factors for OS.

CONCLUSIONS

HGSOC intratumoural vasculature did not undergo significant changes during disease progression. High concentration of CD31⁽⁺⁾ vessels seems to promote recruitment of effector TILs. The study also provides preliminary evidence of the correlation between VEGF-positivity and BRCA status.

FSH receptor binding inhibitor impacts K-Ras and c-Myc of ovarian cancer and signal pathway

The present study aimed to investigate FSHreceptor binding inhibitor (FRBI) effects on relative factors (K-Ras, c-Myc and Vascular endothelial growth factor (VEGF)) to ovarian cancer, and expression levels of FSH receptor (FSHR) mRNAs and proteins in the cumulus-oocyte complex (COCs), to determine changes of protein kinase A (PKA) in sheep granulosa cells, further to elucidate signaling pathway of FRBI action. COCs were cultured in vitro for 24h under supplementation of varying concentrations of FRBI (0, 10, 20, 30 and 40μg/mL) or FSH (10IU/mL). Concentrations of K-Ras, c-Myc, VEGF, cAMP and FSH were detected in IVM media fluids, respectively. The results showed that the concentrations of c-Myc, K-Ras and FSH of FRBI groups were gradually reduced with the increase of FRBI doses. VEGF level of the FRBI-4 group was significantly greater than control group (CG). Expression levels FSHR mRNA and protein and PKA of FRBI-3 and FRBI-4 groups were less than that of CG or FSH group (P<0.05 or P<0.01). Inositol trisphosphate (IP3) concentrations of FRBI-3 and FRBI-4 groups were less than FSH group (P<0.05). FRBI administration doses had significant negative correlations to levels or concentrations of K-Ras, c-Myc, VEGF, FSHR mRNA and protein and PKA protein. K-Ras had significant positive correlations with FSHR mRNA and protein and PKA protein. In conclusion, FRBI could promote the production of VEGF of sheep COCs. Higher doses of FRBI (30 and 40μg/mL) suppressed the production of c-Myc and K-Ras, and declined FSH concentrations in the IVM medium fluid, and decreased the expressions of FSHR at the gene and protein levels, additionally attenuated expression of PKA protein in the granulosa cells.

[Recommendations for biomarker testing in epithelial ovarian cancer. A national consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology]

Advances in the understanding of the histological and molecular characteristics of ovarian cancer now allow 5subtypes to be identified, leading to a more refined therapeutic approach and improved clinical trials. Each of the subtypes has specific histological features and a particular biomarker expression, as well as mutations in different genes, some of which have prognostic and predictive value. CA125 and HE4 are examples of ovarian cancer biomarkers used in diagnosis and follow-up. Currently, somatic or germinal mutations on BRCA1 and BRCA2 genes are the most important biomarkers in epithelial ovarian cancer, having prognostic and predictive value. In this article, a group of experts from the Spanish Society of Medical Oncology and the Spanish Society of Pathology review the histological and molecular characteristics of the 5subtypes of ovarian cancer and describe the most useful biomarkers and mutations for diagnosis, screening and tailored treatment strategy.

The Prognostic 97 Chemoresponse Gene Signature in Ovarian Cancer

Patient diagnosis and care would be significantly improved by understanding the mechanisms underlying platinum and taxane resistance in ovarian cancer. Here, we aim to establish a gene signature that can identify molecular pathways/transcription factors involved in ovarian cancer progression, poor clinical outcome, and chemotherapy resistance. To validate the robustness of the gene signature, a meta-analysis approach was applied to 1,020 patients from 7 datasets. A 97-gene signature was identified as an independent predictor of patient survival in association with other clinicopathological factors in univariate [hazard ratio (HR): 3.0, 95% Confidence Interval (CI) 1.66–5.44, p = 2.7E-4] and multivariate [HR: 2.88, 95% CI 1.57–5.2, p = 0.001] analyses. Subset analyses demonstrated that the signature could predict patients who would attain complete or partial remission or no-response to first-line chemotherapy. Pathway analyses revealed that the signature was regulated by HIF1α and TP53 and included nine HIF1α-regulated genes, which were highly expressed in non-responders and partial remission patients than in complete remission patients. We present the 97-gene signature as an accurate prognostic predictor of overall survival and chemoresponse. Our signature also provides information on potential candidate target genes for future treatment efforts in ovarian cancer.

Recommendations for biomarker testing in epithelial ovarian cancer: a National Consensus Statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology

Because of advances in the understanding of histological and molecular characteristics in ovarian cancer, it is now possible to recognize the existence of five subtypes, which in turn has allowed a more refined therapeutic approach and better design of clinical trials. Each of these five subtypes has specific histological features and a particular biomarker expression, as well as mutations in different genes, some of which have prognostic and predictive value. CA125 and HE4 are examples of ovarian cancer biomarkers used in the diagnosis and follow-up of these malignancies. Currently, somatic or germinal mutations on BRCA1 and BRCA2 genes are the most important biomarkers in epithelial ovarian cancer having prognostic and predictive value. This article will review the histological and molecular characteristics of the five subtypes of ovarian cancer, describing the most important biomarkers and mutations that can guide in diagnosis, screening and tailored treatment strategy.

Identification of Pharmacologically Tractable Protein Complexes in Cancer Using the R-Based Network Clustering and Visualization Program MCODER

Current multiomics assay platforms facilitate systematic identification of functional entities that are mappable in a biological network, and computational methods that are better able to detect densely connected clusters of signals within a biological network are considered increasingly important. One of the most famous algorithms for detecting network subclusters is Molecular Complex Detection (MCODE). MCODE, however, is limited in simultaneous analyses of multiple, large-scale data sets, since it runs on the Cytoscape platform, which requires extensive computational resources and has limited coding flexibility. In the present study, we implemented the MCODE algorithm in R programming language and developed a related package, which we called MCODER. We found the MCODER package to be particularly useful in analyzing multiple omics data sets simultaneously within the R framework. Thus, we applied MCODER to detect pharmacologically tractable protein-protein interactions selectively elevated in molecular subtypes of ovarian and colorectal tumors. In doing so, we found that a single molecular subtype representing epithelial-mesenchymal transition in both cancer types exhibited enhanced production of the collagen-integrin protein complex. These results suggest that tumors of this molecular subtype could be susceptible to pharmacological inhibition of integrin signaling.