Establishment of COS-JC cells persistently producing archetype JC polyomavirus.

JC polyomavirus (JCPyV) is the causative agent of progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the central nervous system in immunocompromised patients. Archetype JCPyV circulates in the human population. There have been several reports of archetype JCPyV replication in cultured cells, in which propagation was not enough to produce high titers of archetype JCPyV. In this study, we carried out cultivation of the transfected cells with archetype JCPyV DNA MY for more than 2 months to establish COS-7 cells (designated COS-JC cells) persistently producing archetype JCPyV. Moreover, JCPyV derived from COS-JC cells was characterized by analyzing the viral propagation, size of the viral genome, amount of viral DNA, production of viral protein, and structure of the non-coding control region (NCCR). Southern blotting using a digoxigenin-labeled JCPyV probe showed two different sizes of the JCPyV genome in COS-JC cells. For molecular cloning, four of five clones showed a decrease in the size of complete JCPyV genome. Especially, clone No. 10 was generated the large deletion within the Large T antigen. On the other hand, the archetype structure of the NCCR was maintained in COS-JC cells, although a few point mutations occurred. Quantitative PCR analysis of viral DNA in COS-JC cells indicated that a high copy number of archetype JCPyV DNA was replicated in COS-JC cells. These findings suggest that COS-JC cells could efficiently propagate archetype JCPyV MY and offer a useful tool to study persistent infection of archetype JCPyV in a kidney-derived system.

CPT11 prevents virus replication in JCI cells persistently infected with JC polyomavirus.

JC polyomavirus (JCPyV) is the causative agent of the demyelinating disease of the central nervous system known as progressive multifocal leukoencephalopathy (PML), which occurs in immunocompromised patients. Moreover, patients treated with natalizumab for multiple sclerosis or Crohn disease can develop PML, which is then termed natalizumab-related PML. Because few drugs are currently available for treating PML, many antiviral agents are being investigated. It has been demonstrated that the topoisomerase I inhibitors topotecan and ß-lapachone have inhibitory effects on JCPyV replication in IMR-32 cells. However, both of these drugs have marginal inhibitory effects on virus propagation in JC1 cells according to RT-PCR analysis. In the present study, the inhibitory effect of another topoisomerase I inhibitor, 7-ethy-10-[4-(1-piperidino)-1-piperidino] carbonyloxy camptothecin (CPT11), was assessed by investigating viral replication, propagation, and viral protein 1 (VP1) production in cultured cells. JCPyV replication was assayed using real-time PCR combined with Dpn I treatment in IMR-32 cells transfected with JCPyV DNA. It was found that JCPyV replicates less in IMR-32 cells treated with CPT11 than in untreated cells. Moreover, CPT11 treatment of JCI cells persistently infected with JCPyV led to a dose-dependent reduction in JCPyV DNA and VP1 production. Additionally, the inhibitory effect of CPT11 was found to be stronger than those of topotecan and ß-lapachone. These findings suggest that CPT11 may be a potential anti-JCPyV agent that could be used to treat PML.

Impaired Japanese encephalitis virus replication in p62/SQSTM1 deficient mouse embryonic fibroblasts.

The role of the autophagy adaptor protein p62/SQSTM1 in Japanese encephalitis virus (JEV) replication in mouse embryonic fibroblasts (MEFs) was investigated. Amounts of JEV RNA and E protein were significantly smaller in p62-deficient cells than wild-type cells at 24 hr post-infection (p.i.). JEV RNA quantitation and viral plaque assays showed significant reductions in viral titers in p62-deficient cell culture fluid. Our results indicate that JEV replication is impaired in p62-deficient MEFs, suggesting that p62 positively regulates JEV replication in host cells.

Suppressive effect of topoisomerase inhibitors on JC polyomavirus propagation in human neuroblastoma cells.

JC polyomavirus (JCPyV) causes progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system, in immunocompromised patients. Because no drugs have been approved for treating PML, many antiviral agents are currently being investigated for this purpose. The inhibitory effects of the topoisomerase I inhibitors topotecan and ß-lapachone were assessed by investigating viral replication, propagation and viral protein 1 (VP1) production in cultured cells. JCPyV replication was assayed using the human neuroblastoma cell line IMR-32 transfected with the JCPyV plasmid and RT- PCR combined with Dpn I treatment. Dpn I digests the input plasmid DNA containing methylated adenosine, but not newly replicated JCPyV DNA, in IMR-32 cells. It was found that JCPyV replicates less in IMR-32 cells treated with topotecan or ß-lapachone than in untreated cells. Moreover, drug treatment of JCI cells, which are IMR-32 cells persistently infected with JCPyV, led to a reduction in the amount of JCPyV DNA and population of VP1-positive cells. These results demonstrate that topotecan and ß-lapachone affects JCPyV propagation in human neuroblastoma cell lines, suggesting that topotecan and ß-lapachone could potentially be used to treat PML.

Replication of IMR-32-adapted JC virus clones in human embryonic kidney cells.

It has been difficult to study JCV replication because of its restricted host range. In this study, JCV replication was examined using different clones in 293 cells. RT-PCR assay revealed that large T antigen expression in cells transfected with IMR-32-adapted JCVs was significantly greater than in those transfected with Mad-1 or CY. DNA replication assay and viral load verified that the IMR-32-adapted JCVs were replication-competent in 293 cells, but not Mad-1 or CY JCVs. These results suggest that a 293 culture system with IMR-32-adapted JCVs may be a useful tool for assessing replication of JCV in vitro.

TNF-α stimulates efficient JC virus replication in neuroblastoma cells.

JC polyomavirus (JCV) causes progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system (CNS) in immunocompromised patients, and particularly in the severe immunosuppression associated with acquired immunodeficiency syndrome (AIDS). HIV-1 can lead to the production of tumor necrosis factor-alpha (TNF-α) in the CNS. Our aim was to examine the effects of TNF-α on JCV gene expression and replication using a human neuroblastoma cell line, IMR-32, transfected with JCV DNA, M1-IMRb. Quantitative RT-PCR analysis of JCV large T antigen and VP1 mRNA, the viral DNA replication assay, and the DNase protection assay were carried out. TNF-α treatment of IMR-32 cells transfected with JCV DNA induced large T antigen mRNA and JCV DNA replication, while other effects on VP1 mRNA expression and virus production were marginal. In addition, ELISA analysis of the nuclear p65 subunit of nuclear factor κB (NF-κB), which is a hallmark of NF-κB pathway activation, of IMR-32 cells upon TNF-α treatment showed that TNF-α treatment activated the NF-κB pathway in IMR-32 cells. Taken together, our results suggest that TNF-α stimulation could induce JCV replication associated with the induction of JCV large T antigen mRNA through the NF-κB pathway in IMR-32 cells transfected with JCV DNA. Our findings may contribute to further understanding of the pathogenesis of AIDS-related PML.

Suppressive effect of PARP-1 inhibitor on JC virus replication in vitro.

The incidence of progressive multifocal leukoencephalopathy (PML) has increased due to the AIDS pandemic, hematological malignancies, and immunosuppressive therapies. Recently, the number of cases of monoclonal antibody-associated PML has increased in patients treated with immunomodulatory drugs such as natalizumab. However, no common consensus regarding PML therapy has been reached in clinical studies. In order to examine the suppression of JC virus (JCV) replication by 3-aminobenzamide (3-AB), a representative PARP-1 inhibitor, a DNA replication assay was carried out using the neuroblastoma cell line IMR-32 and IMR-adapted JCV. The suppression of JCV propagation by 3-AB was also examined using JCI cells, which are a carrier culture producing continuously high JCV titers. The results indicated that PARP-1 inhibitors, such as 3-aminobenzamide (3-AB), suppress JCV replication and propagation significantly in vitro, as judged by DNA replication assay, hemagglutination, and real-time PCR analysis. It has been also shown that 3-AB reduced PARP-1 activity in IMR-32 cells. According to the results of the MTT assay, the enzyme activity of 3-AB-treated cells was slightly lower than that of DMSO-treated cells. However, the significant suppression of JCV propagation is not related to the slight decrease in cell growth. To our knowledge, this is the first report that PARP-1 inhibitor suppresses the replication of JCV significantly in neuroblastoma cell lines via the reduction of PARP-1 activity. Thus, PARP-1 inhibitors also may be a novel therapeutic drug for PML.

Chronic ingestion of ethanol induces hepatocellular carcinoma in mice without additional hepatic insult.

BACKGROUND: Chronic intake of alcohol increases the risk of gastrointestinal and hepatic carcinogenesis. The present study was focused to investigate the incidence and mechanism of pathogenesis of hepatocellular carcinoma (HCC) during chronic ingestion of alcohol without any additional hepatic injury. METHODS: Ethanol was administered to Institute for Cancer Research male mice through drinking water for 70 weeks at concentrations of 5 % (first week), 10 % (next 8 weeks), and 15 % thereafter. The animals were killed at 60 and 70 weeks, the livers were examined for hepatic tumors, and evaluated for foci of cellular alteration (FCA). Immunohistochemical staining was performed in the liver sections for cytochrome P4502E1 (CYP2E1), 4-hydroxy-nonenal (4-HNE), and proto-oncogene, c-Myc. RESULTS: At the 60th week, 40 % of the mice in the ethanol group had visible white nodules (5-10 mm) in the liver, but not in the control mice. At the 70th week, several larger nodules (5-22 mm) were present in the livers of 50 % mice in the ethanol group. In the control group, one mouse developed a single nodule. All nodules were histologically trabecular HCC composed of eosinophilic and vacuolated cells. In the livers of both control and ethanol group, several foci with cellular alteration were present, which were significantly higher in ethanol group. Staining for CYP2E1, 4-HNE and c-Myc depicted marked upregulation of all these molecules in the FCA. CONCLUSIONS: Our data demonstrated that upregulation of CYP2E1 and subsequent production of reactive oxygen species along with the persistent expression of c-Myc play a significant role in the pathogenesis of HCC during chronic ingestion of ethanol.

AT motif binding factor 1 (ATBF1) is highly phosphorylated in embryonic brain and protected from cleavage by calpain-1.

ATBF1 is a transcription factor that regulates genes responsible for repairing tissues and the protection of cells from oxidative stress. Therefore reduction of ATBF1 promotes susceptibility to varieties of human diseases including neurodegenerative diseases and malignant tumors. The instability of the protein was found to be an important background of diseases. Because ATBF1 is composed of a large 404-kDa protein, it can be easily targeted by proteinases. The protein instability should be a serious problem for the function in the cells and practically for our biochemical study of ATBF1. We have found that calpain-1 is a protease responsible for the degeneration of ATBF1. We observed distinct difference between embryo and adult brain derived ATBF1 regarding the sensitivity to calpain-1. The comparative study showed that eight phosphorylated serine residues (Ser1600, Ser2634, Ser2795, Ser2804, Ser2900, Ser3431, Ser3613, Ser3697) in embryonic brain, but only one site (Ser2634) in adult brain. As long as these amino acids were phosphorylated, ATBF1 derived from embryonic mouse brain showed resistance to cleavage; however, treatment with calf intestine alkaline phosphatase sensitized ATBF1 to be digested by calpain-1. An inhibitor (FK506) against calcineurin, which is a serine/threonine specific phosphatase enhanced the resistance of ATBF1 against the digestion by calpain-1. Taken together, these results demonstrate that these phosphorylation sites on ATBF1 function as a defensive shield to calpain-1.

Exogenous human immunodeficiency virus-1 protein, Tat, enhances replication of JC virus efficiently in neuroblastoma cell lines.

The high incidence of progressive multifocal leukoencephalopathy (PML) among individuals with acquired immunodeficiency syndrome (AIDS) is similar to the incidence of other immunocompromised diseases. The pathogenic JC virus (JCV) with rearranged regulatory regions (PML-type) causes PML, a demyelinating disease in the brains of immunocompromised patients. In a previous study, Tat protein, encoded by human immunodeficiency virus type 1 (HIV-1), markedly enhanced the expression of a reporter gene under control of the JCV late promoter. In order to examine the enhancement of JCV replication by Tat protein, the neuroblastoma cell line IMR-32 was used because it enables IMR-32-adapted JCV. The extent of JCV replication in IMR-32 cells treated with Tat protein was significantly higher than that in untreated IMR-32 cells. The enhancement of JCV propagation by Tat protein was also examined using IMR-32-derived JCV producing (JCI) cells which continuously produce JCV. Treatment of JCI cells with Tat protein led to a significant increase in the titers of progeny viruses. It has also been shown that Tat protein leads to a decrease in the expression of purine-rich element binding protein α (Purα) as an important mediator of JCV replication in IMR-32 cells. Thus, it is probable that Tat protein enhances JCV replication in IMR-32 cells via the down-regulation of Purα expression and cell proliferation. To our knowledge, this is the first report that exogenous Tat protein enhances the replication of JCV efficiently in neuroblastoma cell lines.

A novel clinical entity, IgG4-related disease (IgG4RD): general concept and details.

IgG4-related disease (IgG4RD) is a novel clinical disease entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells. IgG4RD may be present in a certain proportion of patients with a wide variety of diseases, including Mikulicz's disease, autoimmune pancreatitis, hypophysitis, Riedel thyroiditis, interstitial pneumonitis, interstitial nephritis, prostatitis, lymphadenopathy, retroperitoneal fibrosis, inflammatory aortic aneurysm, and inflammatory pseudotumor. Although IgG4RD forms a distinct, clinically independent disease category and is attracting strong attention as a new clinical entity, many questions and problems still remain to be elucidated, including its pathogenesis, the establishment of diagnostic criteria, and the role of IgG4. Here we describe the concept of IgG4RD and up-to-date information on this emerging disease entity.

Characterization of JC Polyomavirus Derived from COS-IMRb Cells.

JC polyomavirus (JCPyV) causes progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the central nervous system affecting immunocompromised patients. The study of PML-type JCPyV in vitro has been limited owing to the inefficient propagation of the virus in cultured cells. In this study, we carried out long-term culture of COS-7 cells (designated as COS-IMRb cells) transfected with PML-type M1-IMRb, an adapted viral DNA with a rearranged non-coding control region (NCCR). The JCPyV derived from COS-IMRb cells were characterized by analyzing the viral replication, amount of virus by hemagglutination (HA), production of viral protein 1 (VP1), and structure of the NCCR. HA assays indicated the presence of high amounts of PML-type JCPyV in COS-IMRb cells. Immunostaining showed only a small population of JCPyV carrying COS-IMRb cells to be VP1-positive. Sequencing analysis of the NCCR of JCPyV after long-term culture revealed that the NCCR of M1-IMRb was conserved in COS-IMRb cells without any point mutation. The JCPyV genomic DNA derived from a clone of COS-IMRb-3 cells was detected, via Southern blotting, as a single band of approximately 5.1 kbp without deletion. These findings suggest the potential of using COS-IMRb-3 cells as a useful tool for screening anti-JCPyV drugs.

Comprehensive analysis of protein-expression changes specific to immunoglobulin G4-related disease.

BACKGROUND AND AIMS: Immunoglobulin 4 (IgG4)-related disease (IgG4-RD) is a lymphoproliferative disorder characterized by elevated serum IgG4 levels and tissue infiltration of IgG4-positive plasma cells. We analyzed the serum proteins, whose levels varied based on the disease state and treatment. MATERIALS AND METHODS: Serum proteins from patients with IgG4-related disease and healthy subjects were resolved using two-dimensional electrophoresis, silver-stained, and scanned. Alternatively, the proteins were labeled with Cy2, Cy3, and Cy5 before electrophoresis. The proteins, whose expression differed significantly between patients and healthy individuals, and between before and after steroid treatment, were identified and validated using enzyme-linked immunosorbent assays. RESULTS: Pre-treatment sera from patients with IgG4-related disease was characterized by increased levels of immunoglobulins such as IgG1, IgG4; inflammatory factors such as α-1 antitrypsin (A1AT); and proteins associated with immune system regulation such as clusterin and leucine-rich α-2-glycoprotein (LRG-1). The serum levels of A1AT, LRG-1 and clusterin, during treatment with prednisolone for up to 12 months revealed that LRG-1 levels were halved after 1 month of treatment, comparable to those in healthy subjects; LRG-1 levels remained normal until the end of treatment. CONCLUSION: LRG-1 could serve as a novel biomarker of IgG4-related diseases.

Epidemiological study on Japanese encephalitis virus distribution in Ishikawa prefecture, Japan, by serological investigation using wild boar sera.

Thirty-seven specimens of wild boar sera were collected from August 2016 to March 2018 in Ishikawa prefecture, Japan. Thirty-two specimens (86.5%) were positive for neutralizing antibodies against Japanese encephalitis virus (JEV). Eight specimens (21.6%) were positive for IgM antibodies against JEV. One sample was obtained from a wild boar captured in February during the winter season. Four other serum specimens obtained during the winter season were positive using a JEV gene-specific PCR assay. Based on IgM and PCR assays, wild boars were infected with JEV during the winter season, suggesting that the prevalence of JEV antibodies in wild boars in Ishikawa is high and JEV activity is possible during winter in this region. In addition, wild boars may play an important role in the infection cycle of JEV.

Multiple shRNA expressions in a single plasmid vector improve RNAi against the XPA gene.

To improve the efficiency of stable knockdown with short hairpin RNA (shRNA), we inserted multiple shRNA expression sequences into a single plasmid vector. In this study, the DNA repair factor XPA was selected as a target gene since it is not essential for cell viability and it is easy to check the functional knockdown of this gene. The efficiency of knockdown was compared among single and triple expression vectors. The single shRNA-expressing vector caused limited knockdown of the target protein in stable transfectants, however, the multiple expression vectors apparently increased the frequency of knockdown transfectants. There were correlations between the knockdown level and marker expression in multiple-expressing transfectants, whereas poorer correlations were observed in single vector transfectants. Multiple-transfectants exhibited reduced efficiency of repair of UV-induced DNA damage and an increased sensitivity to ultraviolet light-irradiation. We propose that multiple shRNA expression vectors might be a useful strategy for establishing knockdown cells.

Morphology and gene analysis of hybrids between two congeneric sea stars with different modes of development.

The sea star Astropecten scoparius has feeding bipinnarian larvae, whereas its congener Astropecten latespinosus has nonfeeding barrel-shaped larvae. To investigate evolutionary changes in the development of asteroids, we performed reciprocal crosses between these two species with different larval forms. In the cross between A. scoparius eggs and A. latespinosus sperm, embryos developed into bipinnaria-like larvae. The larvae exhibited either a functional digestive system (a maternal feature) or a nonfunctional digestive system with the tip of the archenteron not connected to the stomodeum (a paternal characteristic). However, in the reciprocal cross between A. latespinosus eggs and A. scoparius sperm, barrel-shaped larvae resembling those of A. latespinosus were produced, in addition to bipinnaria-like larvae, some with functional digestive systems and some with nonfunctional ones. Juveniles were produced from all types of crosses. 18S rDNA was used as a gene marker in cycle sequencing analysis to investigate the genetic features of these juveniles. The sequences of juveniles from bipinnaria-like larvae showed double-peak nucleotide signals, indicating a biparental genome. On the other hand, juveniles from barrel-shaped larvae from A. latespinosus eggs and A. scoparius sperm showed the same sequence as A. latespinosus juveniles. This suggests that bipinnaria-like larvae of both crosses are always hybrids, whereas barrel-shaped larvae develop parthenogenetically.

An Ecological Survey of Mosquitoes and the Distribution of Japanese Encephalitis Virus in Ishikawa Prefecture, Japan, between 2010 and 2014.

Japanese encephalitis virus (JEV) is a flavivirus, responsible for over 30,000 annual cases of encephalitis worldwide, with a mortality rate of approximately 30%. Therefore, it is important to examine the distribution of mosquitos carrying JEV in the fields, even though recently, the number of Japanese encephalitis cases has been approximately 5 per year in Japan. We report the seasonal dynamics of mosquitoes between 2010 and 2014 in Ishikawa Prefecture, Japan. We collected 39,308 female adult mosquitoes, 98.2% of which were classified as Culex tritaeniorhynchus Giles. We identified JEV genomic RNA belonging to genotype 1 from the homogenate of Cx. tritaeniorhynchus, collected during our study using reverse transcription-PCR and nucleotide sequencing techniques. Our results indicate that mosquito vectors for JEV are distributed not only in areas in Ishikawa, but also throughout Japan, and the results suggest that we must be careful regarding JEV outbreaks in Japan in the future.

High FDG uptake on PET is associated with negative cell-to-cell adhesion molecule E-cadherin expression in lung adenocarcinoma.

OBJECTIVES: E-cadherin is a main cell-to-cell adhesion molecule. A negative expression of E-cadherin correlates with distant metastasis in lung cancer. Recently, it was reported that there is an association between FDG uptake on PET and epithelial-mesenchymal transition (EMT) in non-small cell lung cancer. Downregulation of E-cadherin is one of the best markers of EMT. The purpose of this study was to compare E-cadherin expression with FDG uptake on PET, cell differentiation, aggressiveness and post-operative recurrence in patients with lung adenocarcinoma, and to investigate whether FDG uptake on PET is associated with E-cadherin expression. METHODS: We retrospectively reviewed 40 lung adenocarcinoma patients who underwent thoracotomy and FDG PET before thoracotomy. These patients were evaluated FDG PET metrics such as standardized uptake value (SUV), the immunohistochemical expression of E-cadherin in surgical specimens, clinicopathological features, including tumor size, pathologic stage, cell differentiation, aggressiveness and post-operative recurrence. RESULTS: High FDG uptake correlated with negative E-cadherin expression (P = 0.043). SUVmax was higher in a negative E-cadherin expression lung adenocarcinoma than in a positive E-cadherin expression lung adenocarcinoma (P = 0.033). Patients with moderately poorly differentiated adenocarcinoma had frequent negative E-cadherin expression or high FDG uptake (P = 0.004, P = 0.0001, respectively). Patients with aggressive adenocarcinoma had frequent negative E-cadherin expression or high FDG uptake (P = 0.004, P = 0.001, respectively). Kaplan-Meier analysis revealed that negative E-cadherin expression or high FDG uptake were strongly correlated with shortened disease-free survival (P = 0.0153, P = 0.0001, respectively). CONCLUSION: High FDG uptake on PET was associated with negative E-cadherin expression in patients with lung adenocarcinoma. Both high FDG uptake and negative E-cadherin expression were strongly correlated with poor differentiation, aggressiveness, and post-operative recurrence. These findings may cause the association between high FDG uptake and negative E-cadherin expression.

RhoGDIbeta lacking the N-terminal regulatory domain suppresses metastasis by promoting anoikis in v-src-transformed cells.

Rho guanine nucleotide dissociation inhibitors (RhoGDIs) regulate the activity of Rho family GTPases. RhoGDIbeta (LyGDI/GDID4/RhoGDI2) has two caspase cleavage sites after Asp19 and Asp55. The resulting cleavage products, DeltaN(1-19)RhoGDIbeta and DeltaN(1-55)RhoGDIbeta, are expressed in cells under conditions that activate caspases. DeltaN(1-19)RhoGDIbeta, which can inhibit GDP dissociation, is implicated in the process of apoptosis, whereas the physiological roles for DeltaN(1-55)RhoGDIbeta, which lacks the ability to inhibit GDP dissociation, are largely unknown. To explore the roles of DeltaN(1-55)RhoGDIbeta, we examined the phenotypes of v-src-transformed metastatic fibroblasts transfected with plasmids for expressing DeltaN(1-55)RhoGDIbeta. Although the expression of DeltaN(1-55)RhoGDIbeta had no effect on the rate of growth in vitro, it suppressed experimental metastasis and decreased the rate of growth in vivo. In addition, DeltaN(1-55)RhoGDIbeta-expressing cells had enhanced adhesion to fibronectin, laminin, and collagens but reduced retention in the lung after intravenous injection. Also, the expression of DeltaN(1-55)RhoGDIbeta promoted anoikis without affecting the levels of activated Rac1 or Cdc42. Furthermore, DeltaN(1-55)RhoGDIbeta did not affect the expression or phosphorylation of focal adhesion kinase, p44/p42 mitogen-activated protein kinases, or Akt1 before or after induction of anoikis. Thus, DeltaN(1-55)RhoGDIbeta appears to promote anoikis by undefined mechanisms, thereby suppressing metastasis in v-src-transformed fibroblasts.

Microvessel density: correlation with 18F-FDG uptake and prognostic impact in lung adenocarcinomas.

UNLABELLED: Although researched for many years, the prognostic value of tumor angiogenesis reflected by microvessel density (MVD) is still controversial, and there have been no previous reports regarding the correlation with 18F-FDG uptake in lung adenocarcinomas. Therefore, in the present study, we investigated the correlation between MVD determined with different endothelial cell antibodies and 18F-FDG uptake and compared the prognostic impact of those factors in lung adenocarcinomas. METHODS: Forty-four patients with 45 lung adenocarcinomas underwent 18F-FDG PET before surgery. Consecutive paraffin-embedded sections obtained from each resected tumor were immunostained for CD31 (a panendothelial cell marker), CD105 (a proliferation-related endothelial cell marker), and CD34/alpha-SMA (for double labeling of endothelial cells and mural cells). Four high-power fields in the area with the highest MVD were selected for analysis. Computer-assisted image analysis was used to assess MVD. RESULTS: MVD staining results for panendothelial cell markers can be classified into 3 microvessel patterns: diffuse, alveolar, and mixed. The highly ordered alveolar pattern is believed to represent preexisting alveolar vessels trapped in lung adenocarcinomas and may have no significant meaning for the aggressiveness of tumors. Preexisting alveolar cells also do not contribute to 18F-FDG uptake. CD105 staining of MVD (CD105-MVD) showed a significantly positive correlation with 18F-FDG uptake (P < 0.0001), whereas CD31 staining of MVD (CD31-MVD) showed a marginally negative correlation with it (P = 0.057). Although CD105-MVD correlated negatively with prognosis, patients with low CD105-MVD, compared with those with high or moderate CD105-MVD, had a much better prognosis in both disease-free and overall survival analyses (P = 0.017 and P = 0.013, respectively). Patients with low CD31-MVD had the worst prognosis (P = 0.032 for disease-free survival analysis and P = 0.179 for overall survival analysis). CONCLUSION: There is no positive correlation between 18F-FDG uptake and MVD determined with panendothelial cell markers (CD31 and CD34); in contrast, there is a marginally negative correlation between them. MVD determined with CD105, which is a proliferation-related endothelial cell marker, reflects active angiogenesis, correlates positively with 18F-FDG uptake, and is a better indicator of prognosis in lung adenocarcinomas.