There is much evidence that hypoxia in the tumor microenvironment enhances tumor progression. In an earlier study, we reported abnormal phenotypes of tumor-associated endothelial cells such as those ...resistant to chemotherapy and chromosomal instability. Here we investigated the role of hypoxia in the acquisition of chromosomal abnormalities in endothelial cells. Tumor-associated endothelial cells isolated from human tumor xenografts showed chromosomal abnormalities, >30% of which were aneuploidy. Aneuploidy of the tumor-associated endothelial cells was also shown by simultaneous in-situ hybridization for chromosome 17 and by immunohistochemistry with anti-CD31 antibody for endothelial staining. The aneuploid cells were surrounded by a pimonidazole-positive area, indicating hypoxia. Human microvascular endothelial cells expressed hypoxia-inducible factor 1 and vascular endothelial growth factor A in response to either hypoxia or hypoxia-reoxygenation, and in these conditions, they acquired aneuploidy in 7 days. Induction of aneuploidy was inhibited by either inhibition of vascular endothelial growth factor signaling with vascular endothelial growth factor receptor 2 inhibitor or by inhibition of reactive oxygen species by N-acetyl-L-cysteine. These results indicate that hypoxia induces chromosomal abnormalities in endothelial cells through the induction of reactive oxygen species and excess signaling of vascular endothelial growth factor in the tumor microenvironment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Recent studies have reported that stromal cells contribute to tumor progression. We previously demonstrated that tumor endothelial cells (TEC) characteristics were different from those of normal ...endothelial cells (NEC). Furthermore, we performed gene profile analysis in TEC and NEC, revealing that suprabasin (SBSN) was upregulated in TEC compared with NEC. However, its role in TEC is still unknown. Here we showed that SBSN expression was higher in isolated human and mouse TEC than in NEC. SBSN knockdown inhibited the migration and tube formation ability of TEC. We also showed that the AKT pathway was a downstream factor of SBSN. These findings suggest that SBSN is involved in the angiogenic potential of TEC and may be a novel TEC marker.
We showed that Suprabasin (SBSN) was highly expressed in human TECs isolated from colon cancer and renal cell carcinoma (RCC). Immunostaining of these two human tumor blood vessels also revealed strong SBSN expression in vivo. To analyze the function of SBSN, TECs were isolated from human tumor xenografts in nude mice. We also found that, SBSN contributed to proangiogenic phenotype of TEC by promoting migration and tube formation through the activation of AKT. This is the first report about the expression and function of SBSN in TEC. This study suggests that SBSN is a novel target for anti‐angiogenic therapy, which is specific for tumor blood vessels.
Oral squamous cell carcinoma (OSCC) impairs functionality and sensuousness resulting in poor quality of life. Biomarkers can predict disease trajectory and lead to effective treatments. ...Transcriptomics have identified genes that are upregulated in tumor endothelial cells (TECs) compared with normal endothelial cells (NECs). Among them, chemokine receptor 7 (CXCR7) is highly expressed in TECs of several cancers and involved in angiogenesis of TECs. However, levels of CXCR7 in OSCC blood vessels have not been fully investigated. In this study, we analyzed the correlation between CXCR7 expression in TECs and clinicopathological factors in OSCC. Immunohistochemistry for CXCR7 and CD34 was performed on 59 OSCC tissue specimens resected between 1996 and 2008 at Hokkaido University Hospital. CXCR7 expression in blood vessels was evaluated by the ratio of CXCR7+/CD34+ blood vessels. CXCR7 expression was 42% and 19% in tumor and non‐tumor parts, respectively, suggesting that CXCR7 expression is higher in TECs than in NECs. CXCR7 expression in TECs correlated with advanced T‐stage and cancer stage. Overall survival and disease‐free survival rates were higher in low‐expressing CXCR7 patients than in high‐expressing. These results suggest that CXCR7 expression in blood vessels may be a useful diagnostic and prognostic marker for OSCC patients.
Bone is a highly vascularized organ that not only plays multiple roles in supporting the body and organs but also endows the microstructure, enabling distinct cell lineages to reciprocally interact. ...Recent studies have uncovered relevant roles of the bone vasculature in bone patterning, morphogenesis, homeostasis, and pathological bone destruction, including osteoporosis and tumor metastasis. This review provides an overview of current topics in the interactive molecular events between endothelial cells and bone cells during bone ontogeny and discusses the future direction of this research area to find novel ways to treat bone diseases.
Antibody detection methods for viral infections have received broad attention due to the COVID-19 pandemic. In addition, there remains an ever-increasing need to quantitatively evaluate the immune ...response to develop vaccines and treatments for COVID-19. Here, we report an analytical method for the rapid and quantitative detection of SARS-CoV-2 antibody in human serum by fluorescence polarization immunoassay (FPIA). A recombinant SARS-CoV-2 receptor binding domain (RBD) protein labeled with HiLyte Fluor 647 (F-RBD) was prepared and used for FPIA. When the anti-RBD antibody in human serum binds to F-RBD, the degree of polarization (P) increases by suppressing the rotational diffusion of F-RBD. The measurement procedure required only mixing a reagent containing F-RBD with serum sample and measuring the P value with a portable fluorescence polarization analyzer after 15 min incubation. We evaluated analytical performance of the developed FPIA system using 30 samples: 20 COVID-19 positive sera and 10 negative sera. The receiver operating characteristic curve drawn with the obtained results showed that this FPIA system had high accuracy for discriminating COVID-19 positive or negative serum (AUC = 0.965). The total measurement time was about 20 min, and the serum volume required for measurement was 0.25 μL. Therefore, we successfully developed the FPIA system that enables rapid and easy quantification of SARS-CoV-2 antibody. It is believed that our FPIA system will facilitate rapid on-site identification of infected persons and deepen understanding of the immune response to COVID-19.
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•The rapid and quantitative detection of SARS-CoV-2 antibody in human serum by FPIA.•SARS-CoV-2 RBD protein labeled with HiLyte Fluor 647 was used for FPIA.•High accuracy for discriminating COVID-19 positive or negative serum (AUC = 0.965).
Tumor blood vessels play an important role in tumor progression and metastasis. We previously reported that tumor endothelial cells (TEC) exhibit several altered phenotypes compared with normal ...endothelial cells (NEC). For example, TEC have chromosomal abnormalities and are resistant to several anticancer drugs. Furthermore, TEC contain stem cell‐like populations with high aldehyde dehydrogenase (ALDH) activity (ALDHhigh TEC). ALDHhigh TEC have proangiogenic properties compared with ALDHlow TEC. However, the association between ALDHhigh TEC and drug resistance remains unclear. In the present study, we found that ALDH mRNA expression and activity were higher in both human and mouse TEC than in NEC. Human NEC:human microvascular endothelial cells (HMVEC) were treated with tumor‐conditioned medium (tumor CM). The ALDHhigh population increased along with upregulation of stem‐related genes such as multidrug resistance 1, CD90, ALP, and Oct‐4. Tumor CM also induced sphere‐forming ability in HMVEC. Platelet‐derived growth factor (PDGF)‐A in tumor CM was shown to induce ALDH expression in HMVEC. Finally, ALDHhigh TEC were resistant to fluorouracil (5‐FU) in vitro and in vivo. ALDHhigh TEC showed a higher grade of aneuploidy compared with that in ALDHlow TEC. These results suggested that tumor‐secreting factor increases ALDHhigh TEC populations that are resistant to 5‐FU. Therefore, ALDHhigh TEC in tumor blood vessels might be an important target to overcome or prevent drug resistance.
There are TEC with high ALDH activity. ALDH expression was induced by tumor‐derived factor.TEC with high ALDH activity show drug resistance.
Multi-drug resistance (MDR) of cancers to chemotherapy including doxorubicin (DOX) is mediated by several factors. To design an effective therapy for the treatment of chemotherapy-resistant cancers, ...it is essential to explore the elements responsible for mediating MDR. However, exploring these factors in detail in a wide range of tumor types is challenging as several critical analytical steps are involved. Here, we demonstrated the way of exploring the factors mediating MDR in the tumor types without performing the analysis at the molecular level of cells. The sensitivities of 15 different types of cancer cells to DOX were evaluated, and the role of P-glycoprotein (P-gp), one of the major efflux-pumps, was explored. A correlation curve was developed between the intracellular amounts of DOX and the sensitivities of cells, and, based on this correlation, the cells were classified in response to the involvement of P-gp that mediates MDR. P-gp plays an active role in mediating MDR of cancer cells where a correlation between the sensitivities of cells and the accumulated DOX exists. In contrast, in cells that show a resistance to DOX but whose sensitivities are independent of the amount of accumulated drug, it was reasonably presumed that mechanisms other than P-gp are likely to be involved in mediating MDR. Based on the correlation between the availability of a drug and cell sensitivity, it would be reasonable to explore the factors governing cancer MDR, which is essential in designing an effective therapeutic approach for treating chemotherapy-resistant cancers using chemotherapeutic drugs.
Tumour growth is dependent on angiogenesis, and tumour blood vessels are recognized as an important target for cancer therapy. Tumour endothelial cells (TECs) are the main targets of anti-angiogenic ...therapy. Unlike the traditionally held view, some TECs may be genetically abnormal and might acquire drug resistance. Therefore, we investigated the drug resistance of TECs and the mechanism by which it is acquired. TECs show resistance to paclitaxel through greater mRNA expression of multidrug resistance 1, which encodes P-glycoprotein, as compared with normal endothelial cells. We found that high levels of vascular endothelial growth factor in tumour-conditioned medium may be responsible for upregulated P-glycoprotein expression. This is a novel mechanism for the acquisition of drug resistance by TECs in a tumour microenvironment. This review focuses on the possibility that TECs can acquire drug resistance.
Tumor endothelial cells (TECs) perform tumor angiogenesis, which is essential for tumor growth and metastasis. Tumor cells produce large amounts of lactic acid from glycolysis; however, the mechanism ...underlying the survival of TECs to enable tumor angiogenesis under high lactic acid conditions in tumors remains poorly understood.
The metabolomes of TECs and normal endothelial cells (NECs) were analyzed by capillary electrophoresis time-of-flight mass spectrometry. The expressions of pH regulators in TECs and NECs were determined by quantitative reverse transcription-PCR. Cell proliferation was measured by the MTS assay. Western blotting and ELISA were used to validate monocarboxylate transporter 1 and carbonic anhydrase 2 (CAII) protein expression within the cells, respectively. Human tumor xenograft models were used to access the effect of CA inhibition on tumor angiogenesis. Immunohistochemical staining was used to observe CAII expression, quantify tumor microvasculature, microvessel pericyte coverage, and hypoxia.
The present study shows that, unlike NECs, TECs proliferate in lactic acidic. TECs showed an upregulated CAII expression both in vitro and in vivo. CAII knockdown decreased TEC survival under lactic acidosis and nutrient-replete conditions. Vascular endothelial growth factor A and vascular endothelial growth factor receptor signaling induced CAII expression in NECs. CAII inhibition with acetazolamide minimally reduced tumor angiogenesis in vivo. However, matured blood vessel number increased after acetazolamide treatment, similar to bevacizumab treatment. Additionally, acetazolamide-treated mice showed decreased lung metastasis.
These findings suggest that due to their effect on blood vessel maturity, pH regulators like CAII are promising targets of antiangiogenic therapy. Video Abstract.
The polyphenol epigallocatechin‐3 gallate (EGCG) in green tea suppresses tumor growth by direct action on tumor cells and by inhibition of angiogenesis, but it is not known whether it specifically ...inhibits tumor angiogenesis. We examined the anti‐angiogenic effect of EGCG on tumor‐associated endothelial cells (TEC), endothelial progenitor cells (EPC), and normal endothelial cells (NEC). EGCG suppressed the migration of TEC and EPC but not NEC. EGCG also inhibited the phosphorylation of Akt in TEC but not in NEC. Furthermore, vascular endothelial growth factor‐induced mobilization of EPC into circulation was inhibited by EGCG. MMP‐9 in the bone marrow plasma plays key roles in EPC mobilization into circulation. We observed that expression of MMP‐9 mRNA was downregulated by EGCG in mouse bone marrow stromal cells. In an in vivo model, EGCG suppressed growth of melanoma and reduced microvessel density. Our study showed that EGCG has selective anti‐angiogenic effects on TEC and EPC. It is suggested that EGCG could be a promising angiogenesis inhibitor for cancer therapy. (Cancer Sci 2009; 100: 1963–1970)
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