RESUMO
Allogeneic haematopoietic stem cell transplantation (allo-HSCT) can potentially cure malignant blood disorders and benign conditions such as haemoglobinopathies and immunologic diseases. However, allo-HSCT is associated with significant complications. The most common and debilitating among them is graft-versus-host disease (GVHD). In GVHD, donor-derived T cells mount an alloimmune response against the recipient. The alloimmune response involves several steps, including recognition of recipient antigens, activation and proliferation of T cells in secondary lymphoid organs, and homing into GVHD-targeted organs. Adhesion molecules on T cells and endothelial cells mediate homing of T cells into lymphoid and non-lymphoid tissues. In this study, we showed that Von Willebrand factor (VWF), an adhesion molecule secreted by activated endothelial cells, plays an important role in mouse models of GVHD. We investigated the effect of the VWF-cleaving protease ADAMTS13 on GVHD. We found that ADAMTS13 reduced the severity of GVHD after bone marrow transplantation from C57BL6 donor to BALB/C recipient mice. A recombinant VWF-A2 domain peptide also reduced GVHD in mice. We showed that ADAMTS13 and recombinant VWF-A2 reduced the binding of T cells to endothelial cells and VWF in vitro, and reduced the number of T cells in lymph nodes, Peyer's patches and GVHD-targeted organs in vivo. We identified LFA-1 (αLß2) as the binding site of VWF on T cells. Our results showed that blocking T-cell homing by ADAMTS13 or VWF-A2 peptide reduced the severity of the GVHD after allo-HSCT, a potentially novel method for treating and preventing GVHD.
Assuntos
Proteína ADAMTS13 , Doença Enxerto-Hospedeiro , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Linfócitos T , Fator de von Willebrand , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/imunologia , Animais , Proteína ADAMTS13/metabolismo , Camundongos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Fator de von Willebrand/metabolismo , Humanos , Transplante Homólogo , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Modelos Animais de Doenças , Transplante de Medula Óssea , Células Endoteliais/metabolismoRESUMO
BACKGROUND: Many patients with glioblastoma multiforme (GBM) develop deep venous thrombosis or pulmonary emboli. Cell-free circulating mitochondria increase after brain injury and are associated with coagulopathy. OBJECTIVES: This study evaluated whether mitochondria play a role in the GBM-induced hypercoagulable state. METHODS: We examined the correlation between cell-free circulating mitochondria and venous thrombosis in patients with GBM and the impact of mitochondria on venous thrombosis in mice with inferior vena cava stenosis. RESULTS: Using plasma samples of 82 patients with GBM, we found that patients with GBM had a higher number of mitochondria in their plasma (GBM with venous thromboembolism [VTE],: 2.8 × 107 mitochondria/mL; GBM without VTE, 1.9 × 107 mitochondria/mL) than that in healthy control subjects (n = 17) (0.3 × 107 mitochondria/mL). Interestingly, patients with GBM and VTE (n = 41) had a higher mitochondria concentration than patients with GBM without VTE (n = 41). In a murine model of inferior vena cava stenosis, intravenous delivery of mitochondria resulted in an increased rate of venous thrombosis compared with that in controls (70% and 28%, respectively). Mitochondria-induced venous thrombi were neutrophil-rich and contained more platelets than those in control thrombi. Furthermore, as mitochondria are the only source of cardiolipin in circulation, we compared the concentration of anticardiolipin immunoglobulin G in plasma samples of patients with GBM and found a higher concentration in patients with VTE (optical density, 0.69 ± 0.04) than in those without VTE (optical density, 0.51 ± 0.04). CONCLUSION: We concluded that mitochondria might play a role in the GBM-induced hypercoagulable state. We propose that quantifying circulating mitochondria or anticardiolipin antibody concentrations in patients with GBM might identify patients at increased risk of VTE.
Assuntos
Glioblastoma , Tromboembolia Venosa , Trombose Venosa , Animais , Camundongos , Glioblastoma/complicações , Constrição Patológica/complicações , Fatores de Risco , Trombose Venosa/complicaçõesRESUMO
Platelets, the primary operatives of hemostasis that contribute to blood coagulation and wound healing after blood vessel injury, are also involved in pathological conditions, including cancer. Malignancy-associated thrombosis is common in ovarian cancer patients and is associated with poor clinical outcomes. Platelets extravasate into the tumor microenvironment in ovarian cancer and interact with cancer cells and non-cancerous elements. Ovarian cancer cells also activate platelets. The communication between activated platelets, cancer cells, and the tumor microenvironment is via various platelet membrane proteins or mediators released through degranulation or the secretion of microvesicles from platelets. These interactions trigger signaling cascades in tumors that promote ovarian cancer progression, metastasis, and neoangiogenesis. This review discusses how interactions between platelets, cancer cells, cancer stem cells, stromal cells, and the extracellular matrix in the tumor microenvironment influence ovarian cancer progression. It also presents novel potential therapeutic approaches toward this gynecological cancer.
RESUMO
The interactions between platelets and cancer cells activate platelets and enhance tumor growth. Platelets increase proliferation and epithelial-mesenchymal transition in cancer cells, inhibit anoikis, enhance the extravasation of cancer cells, and protect circulating tumor cells against natural killer cells. Here, we have identified another mechanism by which platelets dampen the immune attack on cancer cells. We found that platelets can blunt the antitumor immune response by increasing the expression of inhibitory immune checkpoint (PD-L1) on ovarian cancer cells in vitro and in vivo. Platelets increased PD-L1 in cancer cells via contact-dependent (through NF-κB signaling) and contact-independent (through TFGßR1/Smad signaling) pathways. Inhibition of NF-κB or TGFßR1 signaling in ovarian cancer cells abrogated platelet-induced PD-L1 expression. Reducing platelet counts or inhibiting platelet functions reduced the expression of PD-L1 in ovarian cancer. On the other hand, an increase in platelet counts increased the expression of PD-L1 in tumor-bearing mice.
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Although radiologic imaging and histologic assessment of tumor tissues are classic approaches for diagnosis and monitoring of treatment response, they have many limitations. These include challenges in distinguishing benign from malignant masses, difficult access to the tumor, high cost of the procedures, and tumor heterogeneity. In this setting, liquid biopsy has emerged as a potential alternative for both diagnostic and monitoring purposes. The approaches to liquid biopsy include cell-free DNA/circulating tumor DNA, long and micro noncoding RNAs, proteins/peptides, carbohydrates/lectins, lipids, and metabolites. Other approaches include detection and analysis of circulating tumor cells, extracellular vesicles, and tumor-activated platelets. Ultimately, reliable use of liquid biopsies requires bioinformatics and statistical integration of multiple datasets to achieve approval in a Clinical Laboratory Improvement Amendments setting. This review provides a balanced and critical assessment of recent discoveries regarding tumor-derived biomarkers in liquid biopsies along with the potential and pitfalls for cancer detection and longitudinal monitoring.
Assuntos
Ácidos Nucleicos Livres , Vesículas Extracelulares , MicroRNAs , Células Neoplásicas Circulantes , Biomarcadores Tumorais/genética , Vesículas Extracelulares/metabolismo , Humanos , Biópsia Líquida/métodos , MicroRNAs/metabolismo , Células Neoplásicas Circulantes/metabolismoRESUMO
BACKGROUND: Podoplanin (PDPN) is a sialylated membrane glycoprotein that binds to C-type lectin-like receptor 2 on platelets resulting in platelet activation. PDPN is expressed on lymphatic endothelial cells, perivascular fibroblasts/pericytes, cancer cells, cancer-associated fibroblasts, and tumor stromal cells. PDPN's expression on malignant epithelial cells plays a role in metastasis. Furthermore, the expression of PDPN in brain tumors (high-grade gliomas) was found to correlate with an increased risk of venous thrombosis. OBJECTIVE: We examined the expression of PDPN and its role in tumor progression and venous thrombosis in ovarian cancer. METHODS: We used mouse models of ovarian cancer and venous thrombosis. RESULTS: Ovarian cancer cells express PDPN and release PDPN-rich extracellular vesicles (EVs), and cisplatin and topotecan (chemotherapies commonly used in ovarian cancer) increase the expression of podoplanin in cancer cells. The expression of PDPN in ovarian cancer cells promotes tumor growth in a murine model of ovarian cancer and that knockdown of PDPN gene expression results in smaller primary tumors. Both PDPN-expressing ovarian cancer cells and their EVs cause platelet aggregation. In a mouse model of venous thrombosis, PDPN-expressing EVs released from HeyA8 ovarian cancer cells produce more frequent thrombosis than PDPN-negative EVs derived from PDPN-knockdown HeyA8 cells. Blood clots induced by PDPN-positive EVs contain more platelets than those in blood clots induced by PDPN-negative EVs. CONCLUSIONS: In summary, our findings demonstrate that the expression of PDPN by ovarian cancer cells promotes tumor growth and venous thrombosis in mice.
Assuntos
Glioma , Neoplasias Ovarianas , Trombose Venosa , Animais , Modelos Animais de Doenças , Células Endoteliais , Camundongos , Agregação Plaquetária , Trombose Venosa/genéticaRESUMO
Induction of nucleic acid sensing-mediated type I interferon (IFN) has emerged as a novel approach to activate the immune system against cancer. Here we show that the depletion of DEAD-box RNA helicase 3X (DDX3X) triggers a tumor-intrinsic type I IFN response in breast cancer cells. Depletion or inhibition of DDX3X activity led to aberrant cytoplasmic accumulation of cellular endogenous double-stranded RNAs (dsRNA), which triggered type I IFN production through the melanoma differentiation-associated gene 5 (MDA5)-mediated dsRNA-sensing pathway. Furthermore, DDX3X interacted with dsRNA-editing ADAR1 and dual depletion of DDX3X and ADAR1 synergistically activated the cytosolic dsRNA pathway in breast cancer cells. Loss of DDX3X in mouse mammary tumors enhanced antitumor activity by increasing the tumor-intrinsic type I IFN response, antigen presentation, and tumor infiltration of cytotoxic T and dendritic cells. These findings may lead to the development of a novel therapeutic approach for breast cancer by targeting DDX3X in combination with immune-checkpoint blockade. SIGNIFICANCE: This study elucidates the novel role of DDX3X in regulating endogenous cellular dsRNA homeostasis and type I IFN signaling in breast cancer. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/13/3607/F1.large.jpg.
Assuntos
Neoplasias da Mama/imunologia , RNA Helicases DEAD-box/antagonistas & inibidores , Regulação Neoplásica da Expressão Gênica , Imunidade Inata/imunologia , Interferon Tipo I/imunologia , Helicase IFIH1 Induzida por Interferon/metabolismo , RNA de Cadeia Dupla/genética , Animais , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/prevenção & controle , Proliferação de Células , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Feminino , Humanos , Interferon Tipo I/metabolismo , Helicase IFIH1 Induzida por Interferon/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We and other investigators have shown that platelets promote metastasis and the growth of tumors. Our rationale for conducting this study is that platelets' prometastatic and progrowth effects depend on a close encounter between platelets and cancer cells. This interaction occurs inside blood vessels with circulating tumor cells and outside blood vessels with cancer cells residing in the tumor parenchyma. Our hypothesis was that platelet extravasation is required for the effect of platelets on tumor growth. Platelets respond to environmental stimuli by activation of G protein-coupled receptors on their surface. We investigated the impact of various platelet G proteins on the growth of ovarian cancer tumors and platelet extravasation. We used mice with platelet-specific deficiency of Gαi2 (Gi), Gα13 (G13), or Gαq (Gq) in a syngeneic ovarian cancer model. We measured the total weight of tumor nodules resected from tumor-bearing mice. We developed methods for automated whole-slide image acquisition and unbiased computerized image analysis to quantify extravasated platelets. We compared the number of platelets inside tumor nodules of platelet G protein-deficient tumor-bearing mice. We found that deficiency of Gi and G13, but not Gq, in platelets resulted in smaller tumors compared with those in corresponding littermates. Deficiency of Gi and G13 in platelets reduced the number of extravasated platelets by >90%, but deficiency of Gq did not reduce the number of extravasated platelets significantly. The lack of Gi or G13 in platelets reduced platelet extravasation into the tumor and tumor growth.
Assuntos
Plaquetas , Neoplasias Ovarianas , Animais , Modelos Animais de Doenças , Feminino , Proteínas de Ligação ao GTP , Humanos , CamundongosRESUMO
Paxillin (PXN), a key component of the focal adhesion complex, has been associated with cancer progression, but the underlying mechanisms are poorly understood. The purpose of this study was to elucidate mechanisms by which PXN affects cancer growth and progression, which we addressed using cancer patient data, cell lines, and orthotopic mouse models. We demonstrated a previously unrecognized mechanism whereby nuclear PXN enhances angiogenesis by transcriptionally regulating SRC expression. SRC, in turn, increases PLAT expression through NF-ĸB activation; PLAT promotes angiogenesis via LRP1 in endothelial cells. PXN silencing in ovarian cancer mouse models reduced angiogenesis, tumor growth, and metastasis. These findings provide a new understanding of the role of PXN in regulating tumor angiogenesis and growth.
Assuntos
Biomarcadores Tumorais/metabolismo , Núcleo Celular/metabolismo , Regulação Neoplásica da Expressão Gênica , Neovascularização Patológica/patologia , Neoplasias Ovarianas/irrigação sanguínea , Paxilina/metabolismo , Animais , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Progressão da Doença , Feminino , Humanos , Masculino , Camundongos , Camundongos Nus , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Paxilina/antagonistas & inibidores , Paxilina/genética , Prognóstico , Taxa de Sobrevida , Ativador de Plasminogênio Tecidual/genética , Ativador de Plasminogênio Tecidual/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Quinases da Família src/genética , Quinases da Família src/metabolismoRESUMO
Purpose: VEGF-targeted therapies have modest efficacy in cancer patients, but acquired resistance is common. The mechanisms underlying such resistance are poorly understood.Experimental Design: To evaluate the potential role of immune cells in the development of resistance to VEGF blockade, we first established a preclinical model of adaptive resistance to anti-VEGF therapy. Additional in vitro and in vivo studies were carried out to characterize the role of macrophages in such resistance.Results: Using murine cancer models of adaptive resistance to anti-VEGF antibody (AVA), we found a previously unrecognized role of macrophages in such resistance. Macrophages were actively recruited to the tumor microenvironment and were responsible for the emergence of AVA resistance. Depletion of macrophages following emergence of resistance halted tumor growth and prolonged survival of tumor-bearing mice. In a macrophage-deficient mouse model, resistance to AVA failed to develop, but could be induced by injection of macrophages. Downregulation of macrophage VEGFR-1 and VEGFR-3 expression accompanied upregulation of alternative angiogenic pathways, facilitating escape from anti-VEGF therapy.Conclusions: These findings provide a new understanding of the mechanisms underlying the modest efficacy of current antiangiogenesis therapies and identify new opportunities for combination approaches for ovarian and other cancers. Clin Cancer Res; 23(22); 7034-46. ©2017 AACR.
Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Macrófagos/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Modelos Animais de Doenças , Feminino , Humanos , Macrófagos/imunologia , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Neovascularização Patológica/tratamento farmacológico , Regiões Promotoras Genéticas , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Thrombocytosis is present in more than 30% of patients with solid malignancies and correlates with worsened patient survival. Tumor cell interaction with various cellular components of the tumor microenvironment including platelets is crucial for tumor growth and metastasis. Although it is known that platelets can infiltrate into tumor tissue, secrete pro-angiogenic and pro-tumorigenic factors and thereby increase tumor growth, the precise molecular interactions between platelets and metastatic cancer cells are not well understood. Here we demonstrate that platelets induce resistance to anoikis in vitro and are critical for metastasis in vivo. We further show that platelets activate RhoA-MYPT1-PP1-mediated YAP1 dephosphorylation and promote its nuclear translocation which induces a pro-survival gene expression signature and inhibits apoptosis. Reduction of YAP1 in cancer cells in vivo protects against thrombocytosis-induced increase in metastasis. Collectively, our results indicate that cancer cells depend on platelets to avoid anoikis and succeed in the metastatic process.Platelets have been associated with increased tumor growth and metastasis but the mechanistic details of this interaction are still unclear. Here the authors show that platelets improve anoikis resistance of cancer cells and increase metastasis by activating Yap through a RhoA/MYPT-PP1 pathway.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Anoikis , Plaquetas/metabolismo , Neoplasias Ovarianas/metabolismo , Fosfoproteínas/metabolismo , Transdução de Sinais , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Plaquetas/citologia , Linhagem Celular Tumoral , Técnicas de Cocultura , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Camundongos Endogâmicos C57BL , Camundongos Nus , Metástase Neoplásica , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Fosfoproteínas/genética , Interferência de RNA , Fatores de Transcrição , Transplante Heterólogo , Proteínas de Sinalização YAPRESUMO
We investigated the effect of platelets on ovarian cancer and the role of adenosine diphosphate (ADP) receptors (P2Y12 and P2Y1) on platelets in the growth of primary ovarian cancer tumors. We showed that in murine models of ovarian cancer, a P2Y12 inhibitor (ticagrelor) reduced tumor growth by 60% compared with aspirin and by 75% compared with placebo. In P2Y12-/- mice, the growth of syngeneic ovarian cancer tumors was reduced by >85% compared with wild-type (WT) mice. In contrast, there was no difference in tumor growth between P2Y1-/- and WT mice. Reconstitution of hematopoiesis in irradiated P2Y12-/- mice by hematopoietic progenitor cells from WT mice (WTâP2Y12-/-) restored tumor growth in P2Y12-/- mice. Finally, knockdown of ecto-apyrase (CD39) on ovarian cancer cells increased tumor growth in tumor-bearing mice. Although in the absence of platelets, ADP, the P2Y12 inhibitor, recombinant apyrase, or knockdown of CD39 did not affect cancer cell proliferation, in the presence of platelets, the P2Y12 inhibitor and recombinant apyrase reduced and knockdown of CD39 increased platelet-enhanced cancer cell proliferation. These results suggest that P2Y12 on platelets and ADP concentration at the interface between cancer cells and platelets affect the growth of primary ovarian cancer tumors in mice. If additional studies in mice and in pilot human trials confirm our results, inhibition of P2Y12 might be a new therapeutic option that can be used in adjuvant to the traditional surgery and chemotherapy in patients with ovarian cancer.
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Plaquetas/metabolismo , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/patologia , Receptores Purinérgicos P2Y12/metabolismo , Receptores Purinérgicos P2Y1/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacologia , Transferência Adotiva , Animais , Antígenos CD/metabolismo , Apoptose/efeitos dos fármacos , Apirase/metabolismo , Plaquetas/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Técnicas de Silenciamento de Genes , Hematopoese/efeitos dos fármacos , Humanos , Camundongos Endogâmicos C57BL , Neoplasias Ovarianas/metabolismo , TicagrelorRESUMO
Purpose: Transforming growth factor ß1 (Tgfß1) plays an important role in cancer. Most of Tgfß1 in plasma is from platelets; thus, we studied whether platelet Tgfß1 has any role in the progression of ovarian cancer, and whether this role is limited to metastasis or also involves the growth of primary tumors.Experimental Design: We compared the growth of murine ovarian cancer cell-induced tumors in platelet-specific Tgfß1-deficient mice and wild-type mice. Using resected tumor nodules, we studied the effect of platelet Tgfß1 on neoangiogenesis and on platelet extravasation into tumors. To investigate the effect of Tgfß1 at different stages of ovarian cancer, we reduced expression of Tgfß1 receptor (its TgfßR1 component) in tumors at different time points after injection of cancer cells, and compared the final tumor size.Results: Lack of platelet Tgfß1 in mice reduced tumor growth, neoangiogenesis, and platelet extravasation. Ovarian cancer tumors in platelet-specific Tgfß1-deficient mice reached less than half of their size in wild-type littermates. Knockdown of TgfßR1 on cancer cells in the first 2 weeks after their injection reduced tumor growth, but was less effective if initiated after 3 weeks.Conclusions: We showed that platelet Tgfß1 increased the growth of primary tumors in murine models of ovarian cancer. We also showed that inhibition of TgfßR1 is more effective in reducing the growth of ovarian cancer if initiated earlier. Our results supported a therapeutic benefit in preventing platelet activation, degranulation, and release of Tgfß1 in ovarian cancer. Clin Cancer Res; 23(18); 5611-21. ©2017 AACR.
Assuntos
Expressão Gênica , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Fator de Crescimento Transformador beta1/genética , Animais , Plaquetas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Modelos Animais de Doenças , Progressão da Doença , Feminino , Xenoenxertos , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neoplasias Ovarianas/metabolismo , RNA Interferente Pequeno/genética , Fatores de Tempo , Fator de Crescimento Transformador beta1/metabolismo , Carga TumoralRESUMO
Cyclooxygenase (COX) is the rate-limiting enzyme in conversion of arachidonic acid to prostanoids, and has two isoforms, COX1 and COX2, which share ~65% amino acid homology. COX1 is universally expressed in many cell types including platelets; however, expression of COX2 is known to be more limited. We examined expression of COX2 mRNA and protein in platelets and platelet-derived microparticles (MPs); using quantitative RT-PCR, immunostaining, and Western blotting. We have detected a significant amount of COX2 in platelets, both at mRNA and protein levels. We found that COX1/COX2 mRNA and protein ratios in platelets were 370:1 and 17:1, respectively. Expression level of COX2 in platelets was less than COX1, but comparable to the expression of COX2 in malignant epithelial cells. Considering the important role of COX2 in tumorigenesis and thrombosis, and the large number of circulating platelets, we propose that platelet COX2 may play an important role in physiologic and pathologic conditions.
Assuntos
Plaquetas/metabolismo , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Expressão Gênica , Micropartículas Derivadas de Células/metabolismo , Ciclo-Oxigenase 1/genética , Ciclo-Oxigenase 1/metabolismo , Humanos , Imuno-Histoquímica , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
BACKGROUND: Ovarian cancer patients have a high risk of developing venous thrombosis. The membrane lipid bilayer of platelets and platelet-derived microparticles (PMP) provides a platform for assembly of coagulation proteins and generation of blood clots. METHODS: We compared the lipid composition of platelets and PMPs in patients with ovarian cancer to those in healthy subjects. We used shotgun lipidomics to quantify 12 classes and 177 species of lipids. RESULTS: We found a significant change in 2 classes of lipids in platelets and PMPs isolated from ovarian cancer patients: higher phosphatidylinositol and lower lyso-phosphatidylcholine. The level of 28 species of lipids was also significantly altered in the direction of an increase in the pro-coagulant and a reduction in the anticoagulant lipids. We found that cancer platelets expressed less lipid phosphate phosphatase 1 (LPP1), a key enzyme in phospholipid biosynthesis pathways, than normal platelets. The reduction in LPP1 might contribute to the changes in the lipid profile of cancer platelets. CONCLUSION: Our results support a procoagulant lipid profile of platelets in ovarian cancer patients that can play a role in the increased risk of venous thrombosis in these patients. GENERAL SIGNIFICANCE: As far as we are aware, our study is the first study on platelet lipidomics in ovarian cancer. The importance of our findings for the future studies are: 1) a similar change in lipid profile of platelets and PMP may be responsible for hypercoagulability in other cancers, and 2) plasma level of high-risk lipids for venous thrombosis may be useful biomarkers.
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Recent studies in patients with ovarian cancer suggest that tumor growth may be accelerated following cessation of antiangiogenesis therapy; however, the underlying mechanisms are not well understood. In this study, we aimed to compare the effects of therapy withdrawal to those of continuous treatment with various antiangiogenic agents. Cessation of therapy with pazopanib, bevacizumab, and the human and murine anti-VEGF antibody B20 was associated with substantial tumor growth in mouse models of ovarian cancer. Increased tumor growth was accompanied by tumor hypoxia, increased tumor angiogenesis, and vascular leakage. Moreover, we found hypoxia-induced ADP production and platelet infiltration into tumors after withdrawal of antiangiogenic therapy, and lowering platelet counts markedly inhibited tumor rebound after withdrawal of antiangiogenic therapy. Focal adhesion kinase (FAK) in platelets regulated their migration into the tumor microenvironment, and FAK-deficient platelets completely prevented the rebound tumor growth. Additionally, combined therapy with a FAK inhibitor and the antiangiogenic agents pazopanib and bevacizumab reduced tumor growth and inhibited negative effects following withdrawal of antiangiogenic therapy. In summary, these results suggest that FAK may be a unique target in situations in which antiangiogenic agents are withdrawn, and dual targeting of FAK and VEGF could have therapeutic implications for ovarian cancer management.
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Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Quinase 1 de Adesão Focal/metabolismo , Proteínas de Neoplasias/metabolismo , Neovascularização Patológica/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Microambiente Tumoral/efeitos dos fármacos , Difosfato de Adenosina/metabolismo , Animais , Anticorpos Antineoplásicos/farmacologia , Bevacizumab/farmacologia , Plaquetas/patologia , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/genética , Linhagem Celular Tumoral , Feminino , Quinase 1 de Adesão Focal/antagonistas & inibidores , Quinase 1 de Adesão Focal/genética , Humanos , Indazóis , Camundongos , Camundongos Knockout , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Neovascularização Patológica/enzimologia , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Pirimidinas/farmacologia , Sulfonamidas/farmacologia , Microambiente Tumoral/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We have previously shown that complement component 3 (C3) is secreted by malignant epithelial cells. To understand the mechanism of upregulation of C3 expression in tumor cells, we studied the C3 promoter and identified that twist basic helix-loop-helix transcription factor 1 (TWIST1) binds to the C3 promoter and enhances its expression. Because TWIST1 mediates epithelial-mesenchymal transition (EMT), we studied the effect of C3 on EMT and found that C3 decreased E-cadherin expression on cancer cells and promoted EMT. We showed that C3-induced reduction in E-cadherin expression in ovarian cancer cells was mediated by C3a and is Krüppel-like factor 5 dependent. We investigated the association between TWIST1 and C3 in malignant tumors and in murine embryos. TWIST1 and C3 colocalized at the invasive tumor edges, and in the neural crest and limb buds of mouse embryos. Our results identified TWIST1 as a transcription factor that regulates C3 expression during pathologic and physiologic EMT.
Assuntos
Complemento C3/biossíntese , Transição Epitelial-Mesenquimal/fisiologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Neoplasias/patologia , Proteínas Nucleares/metabolismo , Proteína 1 Relacionada a Twist/metabolismo , Animais , Western Blotting , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Complemento C3/genética , Feminino , Humanos , Imuno-Histoquímica , Camundongos , Mutagênese Sítio-Dirigida , Neoplasias/genética , Neoplasias/metabolismo , Proteínas Nucleares/genética , RNA Interferente Pequeno , Reação em Cadeia da Polimerase em Tempo Real , Transfecção , Proteína 1 Relacionada a Twist/genéticaRESUMO
While recombinant human erythropoietin (rhEpo) has been widely used to treat anemia in cancer patients, concerns about its adverse effects on patient survival have emerged. A lack of correlation between expression of the canonical EpoR and rhEpo's effects on cancer cells prompted us to consider the existence of an alternative Epo receptor. Here, we identified EphB4 as an Epo receptor that triggers downstream signaling via STAT3 and promotes rhEpo-induced tumor growth and progression. In human ovarian and breast cancer samples, expression of EphB4 rather than the canonical EpoR correlated with decreased disease-specific survival in rhEpo-treated patients. These results identify EphB4 as a critical mediator of erythropoietin-induced tumor progression and further provide clinically significant dimension to the biology of erythropoietin.
Assuntos
Neoplasias da Mama/genética , Eritropoetina/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Ovarianas/genética , Receptor EphB4/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Western Blotting , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Progressão da Doença , Eritropoetina/genética , Feminino , Humanos , Estimativa de Kaplan-Meier , Células MCF-7 , Camundongos Endogâmicos C57BL , Camundongos Nus , Pessoa de Meia-Idade , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Ligação Proteica/efeitos dos fármacos , Receptor EphB4/metabolismo , Receptores da Eritropoetina/genética , Receptores da Eritropoetina/metabolismo , Proteínas Recombinantes/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Adulto JovemRESUMO
PURPOSE: XPO1 inhibitors have shown promise for cancer treatment, and yet the underlying mechanisms for the antitumor effects are not well understood. In this study, we explored the usefulness of selective inhibitors of nuclear export (SINE) compounds that are specific inhibitors of XPO1. EXPERIMENTAL DESIGN: We used proteomic analysis in XPO1 inhibitor-treated ovarian cancer cell lines and examined antitumor effects in ovarian and breast cancer mouse models. We also studied the effects of XPO1 inhibitor in combination with chemotherapeutic agents. RESULTS: XPO1 inhibitor treatment substantially increased the percentage of apoptotic cells (60%) after 72 hours of incubation. XPO1 inhibitor promoted the accumulation of eIF5A in mitochondria, leading to cancer cell death. Topotecan showed the greatest synergistic effect with XPO1 inhibitor. XPO1 inhibitors prevented the translocation of IGF2BP1 from the nucleus to the cytoplasm, thereby permitting the localization of eIF5A in the mitochondria. This process was p53, RB, and FOXO independent. Significant antitumor effects were observed with XPO1 inhibitor monotherapy in orthotopic ovarian (P < 0.001) and breast (P < 0.001) cancer mouse models, with a further decrease in tumor burden observed in combination with topotecan or paclitaxel (P < 0.05). This mitochondrial accumulation of eIF5A was highly dependent on the cytoplasmic IGF2BP1 levels. CONCLUSIONS: We have unveiled a new understanding of the role of eIF5A and IGF2BP1 in XPO1 inhibitor-mediated cell death and support their clinical development for the treatment of ovarian and other cancers. Our data also ascertain the combinations of XPO1 inhibitors with specific chemotherapy drugs for therapeutic trials.