Reactive stromal cells are an integral part of tumor microenvironment (TME) and interact with cancer cells to regulate their growth. Although targeting stromal cells could be a viable therapy to ...regulate the communication between TME and cancer cells, identification of stromal targets that make cancer cells vulnerable has remained challenging and elusive. Here, we identify a previously unrecognized mechanism whereby metabolism of reactive stromal cells is reprogrammed through an upregulated glutamine anabolic pathway. This dysfunctional stromal metabolism confers atypical metabolic flexibility and adaptive mechanisms in stromal cells, allowing them to harness carbon and nitrogen from noncanonical sources to synthesize glutamine in nutrient-deprived conditions existing in TME. Using an orthotopic mouse model for ovarian carcinoma, we find that co-targeting glutamine synthetase in stroma and glutaminase in cancer cells reduces tumor weight, nodules, and metastasis. We present a synthetic lethal approach to target tumor stroma and cancer cells simultaneously for desirable therapeutic outcomes.
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•CAFs have an upregulated glutamine anabolic pathway compared to NOFs•CAFs harness atypical carbon and nitrogen sources for glutamine synthesis•Crosstalk between stromal-epithelial cells augments dysregulated metabolism in CAFs•Targeting stromal GS in an orthotopic ovarian cancer model induces tumor regression
Yang et al. reveal that cancer-associated fibroblasts boost glutamine production by harnessing carbon and nitrogen from atypical nutrient sources to maintain cancer cell growth when glutamine is scarce. Co-targeting stromal glutamine synthetase and cancer cell glutaminase disrupts this metabolic crosstalk, inducing tumor regression in an ovarian carcinoma mouse model.
Advanced ovarian cancer usually spreads to the visceral adipose tissue of the omentum. However, the omental stromal cell-derived molecular determinants that modulate ovarian cancer growth have not ...been characterized. Here, using next-generation sequencing technology, we identify significantly higher levels of microRNA-21 (miR21) isomiRNAs in exosomes and tissue lysates isolated from cancer-associated adipocytes (CAAs) and fibroblasts (CAFs) than in those from ovarian cancer cells. Functional studies reveal that miR21 is transferred from CAAs or CAFs to the cancer cells, where it suppresses ovarian cancer apoptosis and confers chemoresistance by binding to its direct novel target, APAF1. These data suggest that the malignant phenotype of metastatic ovarian cancer cells can be altered by miR21 delivered by exosomes derived from neighbouring stromal cells in the omental tumour microenvironment, and that inhibiting the transfer of stromal-derived miR21 is an alternative modality in the treatment of metastatic and recurrent ovarian cancer.
Ovarian cancer is the most lethal gynecological malignancy. It is usually diagnosed at a late stage, with a 5-yr survival rate of <30%. The majority of ovarian cancer cases are diagnosed after tumors ...have widely spread within the peritoneal cavity, limiting the effectiveness of debulking surgery and chemotherapy. Owing to a substantially lower survival rate at late stages of disease than at earlier stages, the major cause of ovarian cancer deaths is believed to be therapy-resistant metastasis. Although metastasis plays a crucial role in promoting ovarian tumor progression and decreasing patient survival rates, the underlying mechanisms of ovarian cancer spread have yet to be thoroughly explored. For many years, researchers have believed that ovarian cancer metastasizes via a passive mechanism by which ovarian cancer cells are shed from the primary tumor and carried by the physiological movement of peritoneal fluid to the peritoneum and omentum. However, the recent discovery of hematogenous metastasis of ovarian cancer to the omentum via circulating tumor cells instigated rethinking of the mode of ovarian cancer metastasis and the importance of the "seed-and-soil" hypothesis for ovarian cancer metastasis. In this review we discuss the possible mechanisms by which ovarian cancer cells metastasize from the primary tumor to the omentum, the cross-talk signaling events between ovarian cancer cells and various stromal cells that play crucial roles in ovarian cancer metastasis, and the possible clinical implications of these findings in the management of this deadly, highly metastatic disease.
The molecular mechanism by which cancer-associated fibroblasts (CAFs) confer chemoresistance in ovarian cancer is poorly understood. The purpose of the present study was to evaluate the roles of CAFs ...in modulating tumor vasculature, chemoresistance, and disease progression. Here, we found that CAFs upregulated the lipoma-preferred partner (LPP) gene in microvascular endothelial cells (MECs) and that LPP expression levels in intratumoral MECs correlated with survival and chemoresistance in patients with ovarian cancer. Mechanistically, LPP increased focal adhesion and stress fiber formation to promote endothelial cell motility and permeability. siRNA-mediated LPP silencing in ovarian tumor-bearing mice improved paclitaxel delivery to cancer cells by decreasing intratumoral microvessel leakiness. Further studies showed that CAFs regulate endothelial LPP via a calcium-dependent signaling pathway involving microfibrillar-associated protein 5 (MFAP5), focal adhesion kinase (FAK), ERK, and LPP. Thus, our findings suggest that targeting endothelial LPP enhances the efficacy of chemotherapy in ovarian cancer. Our data highlight the importance of CAF-endothelial cell crosstalk signaling in cancer chemoresistance and demonstrate the improved efficacy of using LPP-targeting siRNA in combination with cytotoxic drugs.
Adipose tissue contains a population of multipotent adipose stem cells (ASCs) that form tumor stroma and can promote tumor progression. Given the high rate of ovarian cancer metastasis to the omental ...adipose, we hypothesized that omental-derived ASC may contribute to ovarian cancer growth and dissemination.
We isolated ASCs from the omentum of three patients with ovarian cancer, with (O-ASC4, O-ASC5) and without (O-ASC1) omental metastasis. BM-MSCs, SQ-ASCs, O-ASCs were characterized with gene expression arrays and metabolic analysis. Stromal cells effects on ovarian cancer cells proliferation, chemoresistance and radiation resistance was evaluated using co-culture assays with luciferase-labeled human ovarian cancer cell lines. Transwell migration assays were performed with conditioned media from O-ASCs and control cell lines. SKOV3 cells were intraperitionally injected with or without O-ASC1 to track in-vivo engraftment.
O-ASCs significantly promoted in vitro proliferation, migration chemotherapy and radiation response of ovarian cancer cell lines. O-ASC4 had more marked effects on migration and chemotherapy response on OVCA 429 and OVCA 433 cells than O-ASC1. Analysis of microarray data revealed that O-ASC4 and O-ASC5 have similar gene expression profiles, in contrast to O-ASC1, which was more similar to BM-MSCs and subcutaneous ASCs in hierarchical clustering. Human O-ASCs were detected in the stroma of human ovarian cancer murine xenografts but not uninvolved ovaries.
ASCs derived from the human omentum can promote ovarian cancer proliferation, migration, chemoresistance and radiation resistance in-vitro. Furthermore, clinical O-ASCs isolates demonstrate heterogenous effects on ovarian cancer in-vitro.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Identification of gene expression profiles of cancer stem cells may have significant implications in the understanding of tumor biology and for the design of novel treatments targeted toward these ...cells. Here we report a potential ovarian cancer stem cell gene expression profile from isolated side population of fresh ascites obtained from women with high-grade advanced stage papillary serous ovarian adenocarcinoma. Affymetrix U133 Plus 2.0 microarrays were used to interrogate the differentially expressed genes between side population (SP) and main population (MP), and the results were analyzed by paired T-test using BRB-ArrayTools. We identified 138 up-regulated and 302 down-regulated genes that were differentially expressed between all 10 SP/MP pairs. Microarray data was validated using qRT-PCR and17/19 (89.5%) genes showed robust correlations between microarray and qRT-PCR expression data. The Pathway Studio analysis identified several genes involved in cell survival, differentiation, proliferation, and apoptosis which are unique to SP cells and a mechanism for the activation of Notch signaling is identified. To validate these findings, we have identified and isolated SP cells enriched for cancer stem cells from human ovarian cancer cell lines. The SP populations were having a higher colony forming efficiency in comparison to its MP counterpart and also capable of sustained expansion and differentiation in to SP and MP phenotypes. 50,000 SP cells produced tumor in nude mice whereas the same number of MP cells failed to give any tumor at 8 weeks after injection. The SP cells demonstrated a dose dependent sensitivity to specific γ-secretase inhibitors implicating the role of Notch signaling pathway in SP cell survival. Further the generated SP gene list was found to be enriched in recurrent ovarian cancer tumors.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Recent studies show that colorectal tumors with high microsatellite instability (MSI-H) have increased immunogenicity and response to immunotherapy compared with microsatellite-stable (MSS) tumors. ...It is not yet clear whether MSI-H endometrial cancer may also benefit from these therapies. It is also unknown whether immune response is equivalent in MSI-H endometrial cancer with sporadic or inherited Lynch syndrome origins.
Multiplexed fluorescent IHC was used to compare matched MSI-H (
= 60) and MSS (
= 96) endometrial cancer specimens by evaluating immune cell populations in tumor and stroma compartments. Sporadic MSI-H and Lynch syndrome-associated (LS) MSI-H endometrial cancers were also directly compared.
Increased immune cells were present in stroma of MSI-H endometrial cancer compared with MSS, including granzyme B
cells, activated CTLs (CD8
granzyme B
), and PD-L1
cells. Granzyme B
cells and activated CTLs were also increased in the tumor compartment of MSI-H endometrial cancers. Comparing sporadic and LS MSI-H endometrial cancer showed distinct differences in immune cell populations, indicating that mechanisms underlying microsatellite instability alter immune response. Specifically, LS MSI-H endometrial cancer showed increased CD8
cells and activated CTLs in stroma, with reduced macrophages in stroma and tumor compared with sporadic MSI-H. Sporadic MSI-H had increased PD-L1
macrophages in stroma and tumor compared with LS MSI-H endometrial cancer.
MSI-H endometrial cancer has increased immune cell infiltration compared with MSS endometrial cancer and the hereditary or sporadic origin of microsatellite instability impacts immune response. Clinical trials to determine the role of immunotherapy in patients with MSI-H endometrial cancer must evaluate Lynch syndrome-related and sporadic MSI-H tumors separately.
.
Cancer‐associated fibroblasts (CAFs) are the most abundant cell type in the tumor microenvironment and are responsible for producing the desmoplastic reaction that is a poor prognostic factor in ...ovarian cancer. Long non‐coding RNAs (lncRNAs) have been shown to play important roles in cancer. However, very little is known about the role of lncRNAs in the tumor microenvironment. We aimed to identify lncRNAs expressed in ovarian CAFs that were associated with patient survival and used computational approaches to predict their function. Increased expression of 9 lncRNAs and decreased expression of 1 lncRNA in ovarian CAFs were found to be associated with poorer overall survival. A “guilt‐by‐association” approach was used to predict the function of these lncRNAs. In particular, MIR155HG was predicted to play a role in immune response. Further investigation revealed high MIR155HG expression to be associated with higher infiltrates of immune cell subsets. In conclusion, these data indicate expression on several lncRNAs in CAFs are associated with patient survival and are likely to play an important role in regulating CAF function.
This manuscript shows that long noncoding RNAs (lncRNAs) are heterogeneously expressed in ovarian cancer‐associated fibroblasts and expression differences in several lncRNAs are associated with differences in patient survival. Expression profiles were analyzed from 67 microdissected ovarian cancer‐associated fibroblast samples, one of the largest cohorts available. One lncRNA, MIR155HG, was associated with increases in tumor‐infiltrating lymphocytes.
Advanced high-grade serous ovarian cancer (HGSC) is an aggressive disease that accounts for 70% of all ovarian cancer deaths. Nevertheless, 15% of patients diagnosed with advanced HGSC survive more ...than 10 years. The elucidation of predictive markers of these long-term survivors (LTS) could help identify therapeutic targets for the disease, and thus improve patient survival rates. To investigate the stromal heterogeneity of the tumor microenvironment (TME) in ovarian cancer, we used spatial transcriptomics to generate spatially resolved transcript profiles in treatment-naïve advanced HGSC from LTS and short-term survivors (STS) and determined the association between cancer-associated fibroblasts (CAF) heterogeneity and survival in patients with advanced HGSC. Spatial transcriptomics and single-cell RNA-sequencing data were integrated to distinguish tumor and stroma regions, and a computational method was developed to investigate spatially resolved ligand-receptor interactions between various tumor and CAF subtypes in the TME. A specific subtype of CAFs and its spatial location relative to a particular ovarian cancer cell subtype in the TME correlated with long-term survival in patients with advanced HGSC. Also, increased APOE-LRP5 cross-talk occurred at the stroma-tumor interface in tumor tissues from STS compared with LTS. These findings were validated using multiplex IHC. Overall, this spatial transcriptomics analysis revealed spatially resolved CAF-tumor cross-talk signaling networks in the ovarian TME that are associated with long-term survival of patients with HGSC. Further studies to confirm whether such cross-talk plays a role in modulating the malignant phenotype of HGSC and could serve as a predictive biomarker of patient survival are warranted.
Generation of spatially resolved gene expression patterns in tumors from patients with ovarian cancer surviving more than 10 years allows the identification of novel predictive biomarkers and therapeutic targets for better patient management. See related commentary by Kelliher and Lengyel, p. 1383.
TGF-β has limited effects on ovarian cancer cells, but its contributions to ovarian tumor growth might be mediated through elements of the tumor microenvironment. In the present study, we tested the ...hypothesis that TGF modulates ovarian cancer progression by modulating the contribution of cancer-associated fibroblasts (CAF) that are present in the microenvironment. Transcriptome profiling of microdissected stromal and epithelial components of high-grade serous ovarian tumors and TGF-β-treated normal ovarian fibroblasts identified versican (VCAN) as a key upregulated target gene in CAFs. Functional evaluations in coculture experiments showed that TGF-β enhanced the aggressiveness of ovarian cancer cells by upregulating VCAN in CAFs. VCAN expression was regulated in CAFs through TGF-β receptor type II and SMAD signaling. Upregulated VCAN promoted the motility and invasion of ovarian cancer cells by activating the NF-κB signaling pathway and by upregulating expression of CD44, matrix metalloproteinase-9, and the hyaluronan-mediated motility receptor. Our work identified a TGF-β-inducible gene signature specific to CAFs in advanced high-grade serous ovarian tumors, and showed how TGF-β stimulates ovarian cancer cell motility and invasion by upregulating the CAF-specific gene VCAN. These findings suggest insights to develop or refine strategies for TGF-β-targeted therapy of ovarian cancer.
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