Caveolin-1 Levels Research Articles

Curcumin enhances vascular contractility via induction of myocardin in mouse smooth muscle cells.

A variety of cardiovascular diseases is accompanied by the loss of vascular contractility. This study sought to investigate the effects of curcumin, a natural polyphenolic compound present in turmeric, on mouse vascular contractility and the underlying mechanisms. After mice were administered curcumin (100 mg·kg-1·d-1, ig) for 6 weeks, the contractile responses of the thoracic aorta to KCl and phenylephrine were significantly enhanced compared with the control group. Furthermore, the contractility of vascular smooth muscle (SM) was significantly enhanced after incubation in curcumin (25 μmol/L) for 4 days, which was accompanied by upregulated expression of SM marker contractile proteins SM22α and SM α-actin. In cultured vascular smooth muscle cells (VSMCs), curcumin (10, 25, 50 μmol/L) significantly increased the expression of myocardin, a "master regulator" of SM gene expression. Curcumin treatment also significantly increased the levels of caveolin-1 in VSMCs. We found that as a result of the upregulation of caveolin-1, curcumin blocked the activation of notch1 and thereby abolished Notch1-inhibited myocardin expression. Knockdown of caveolin-1 or activation of Notch1 signaling with Jagged1 (2 μg/mL) diminished these effects of curcumin in VSMCs. These findings suggest that curcumin induces the expression of myocardin in mouse smooth muscle cells via a variety of mechanisms, including caveolin-1-mediated inhibition of notch1 activation and Notch1-mediated repression of myocardin expression. This may represent a novel pathway, through which curcumin protects blood vessels via the beneficial regulation of SM contractility.

Sclareol inhibits cell proliferation and sensitizes cells to the antiproliferative effect of bortezomib via upregulating the tumor suppressor caveolin-1 in cervical cancer cells.

The anticancer effect of sclareol has long been reported, however, the exact mechanisms underlying the antitumorigenic effect of sclareol in cervical carcinoma remain to be fully elucidated. The present study analyzed cell proliferation and cell apoptosis by MTT and FITC-Annexin V assays. The protein levels of caveolin-1 (Cav-1) and copper-zinc superoxide dismutase (SOD)1 were determined by western blotting, and the interaction of Cav1 and HSC70 was investigated by co-immunoprecipitation experiments. The present study found that sclareol inhibited cell proliferation and induced apoptosis in HeLa cells. Two cancer-associated proteins, Cav1 and SOD1 were identified as potential targets of sclareol in HeLa cells. The expression of Cav1 increased when the cells were treated with sclareol, and the protein level of SOD1 was negatively correlated with Cav1. The overexpression of Cav1 enhanced the sensitivity of the HeLa cells to sclareol treatment and downregulated the protein level of SOD1, which exhibited potential associations between Cav1 and SOD1. In addition, sclareol significantly sensitized several cancer cells to the anticancer effect of bortezomib by targeting Cav1 and SOD1. Taken together, the results of the present study demonstrated that sclareol inhibited tumor cell growth through the upregulation of Cav1, and provides a potential therapeutic target for human cancer.

Role of caveolin-1/vascular endothelial growth factor pathway in basic fibroblast growth factor-induced angiogenesis and neurogenesis after treadmill training following focal cerebral ischemia in rats

Exercise is known to aid functional recovery following ischemia, though the mechanisms responsible for the beneficial effects of exercise on recovery from ischemic stroke are not fully understood. Basic fibroblast growth factor (bFGF) contributes to angiogenesis and promotes neurologic functional recovery after stroke. The present study aimed to investigate the possible mechanisms whereby treadmill exercise ameliorated impaired angiogenesis and neurogenesis following transient cerebral ischemia in middle cerebral artery occlusion (MCAO) rats. Treadmill exercise was started 2days after ischemia-reperfusion in MCAO rats and continued until 7 or 28days after MCAO, after which the animals were sacrificed. Changes in neurological deficit, infarction volume, neuronal morphology, expression levels of bFGF, caveolin-1, and vascular endothelial growth factor (VEGF), and angiogenesis and neurogenesis in the ischemic penumbra were examined by reverse transcription-polymerase chain reaction, western blots, and/or double immunofluorescence. The results suggested that treadmill exercise promoted the expression of bFGF, improved neurological recovery, and reduced infarct volume compared with non-exercised rats, and also enhanced the expression of caveolin-1, VEGF, VEGF receptor 2(FIK-1)/CD34, and Brdu/nestin staining. Small interfering RNA targeting bFGF blocked the protective effects of bFGF. In addition, 4weeks of post-stroke recovery still ameliorated ischemia-induced damage without bFGF shRNA. These findings suggest a novel mechanism underlying the beneficial effects of bFGF following stroke, and indicate that treadmill exercise may aid stroke recovery by regulating the caveolin-1/VEGF pathway in the ischemic zone.

MiR-124-3p attenuates hyperphosphorylation of Tau protein-induced apoptosis via caveolin-1-PI3K/Akt/GSK3β pathway in N2a/APP695swe cells.

Hyperphosphorylation of Tau forming neurofibrillary tangles has been considered as a crucial event in the pathogenesis of Alzheimer's disease (AD). MiR-124-3p belongs to microRNA (miRNA) family and was markedly decreased in AD, however, the functions of miR-124-3p in the pathogenesis of AD remain unknown. We observed that the expression of miR-124-3p was significantly decreased in N2a/APP695swe cells; and transfection of miR-124-3p mimics not only attenuated cell apoptosis and abnormal hyperphosphorylation of Tau protein without any changes of total Tau protein, but also increased expression levels of Caveolin-1, phosphoinositide 3-kinase (PI3K), phospho-Akt (Akt-Ser473)/Akt, phospho-glycogen synthase kinase-3 beta (GSK-3β-Ser9)/GSK-3β in N2a/APP695swe cells. We further found that miR-12-3p directly targeted Caveolin-1; miR-124-3p inhibited abnormal hyperphosphorylation of Tau by regulating Caveolin-1-PI3K/Akt/GSK3β pathway in AD. This study reveals that miR-124-3p may play a neuroprotective role in AD, which may provide new ideas and therapeutic targets for AD.

Abstract 110: Caveolin-1 and Arterial Remodeling in Adult Moyamoya Disease

Background and purpose: Moyamoya disease (MMD) is a unique cerebrovascular occlusive disease that is characterized by progressive stenosis and negative remodeling of the distal internal carotid artery (ICA). We hypothesized that caveolin-1, a protein that controls the regulation of endothelial vesicular trafficking and signal transduction, is associated with negative remodeling in MMD. Methods: We prospectively recruited 77 consecutive patients with MMD (49 bilateral and 28 unilateral MMD) diagnosed by conventional angiography. Seventeen patients with intracranial atherosclerotic stroke and no RNF213 mutation served as controls. Distal ICA outer diameters were examined with high-resolution MRI. We evaluated whether the degree of negative remodeling in MMD patients was associated with RNF213 polymorphism, caveolin-1 levels, or various clinical and vascular risk factors. Results: The RNF213 variant was observed in 49 (63.6%) patients with MMD. The serum caveolin-1 (ng/mL) level was lower in MMD patients than in controls (0.47±0.29 vs. 0.86±0.68, P =0.034). The mean ICA diameter was 2.48±0.98 mm (range 0.00-4.76) for the 126 affected distal ICAs in MMD patients and 3.84±0.42 mm for asymptomatic ICAs in controls. After adjusting for possible confounders, male sex (coefficient, 0.396; P =0.029), clinical presentation with ischemic stroke (coefficient, -0.733; P <0.001), and caveolin-1 level (coefficient, 1.018; P <0.001) were independently associated with distal ICA diameter in MMD patients. Conclusion: Our findings suggest that caveolin-1 may play a major role in arterial negative remodeling in MMD patients. Future studies exploring caveolin-1 as a therapeutic target in MMD are warranted.

Serum caveolin-1 and fibronectin levels as clinical markers for patients with malignant melanoma

Serum caveolin-1 and fibronectin levels as clinical markers for patients with malignant melanoma

Abstract B02: Open multi-microwell array for the study of paracrine signaling in tumors

Abstract The development and progression of tumors are modulated by the interaction among multiple cell types present at the tumor adjacent tissue. Few in vitro cell culture platforms allow one to test multi-cellular interactions and those suitable require high numbers of cells limiting studies to cell lines and excluding heterogeneous patient samples, and fail to provide tunable discrete adjacent compartments for the retrieval of independent cell population readouts. Mixing of cells in adjacent compartments and cell sorting after mixed culture represent a costly and time consuming procedure that often results is lost, reduction and/or damage of the recovered sample. To overcome some of these limitations we have developed an open multi-microwell array that enables co-culture of up to 4 cell populations in discrete adjacent wells using either 2- or 3-dimension culture conditions. The circular microwells are made of poly-dimethyl siloxane (PDMS) and placed on top of glass or tissue culture plastic. The open-well format allows cells and culture media to be manually loaded and replaced using a pipette independently of passive pumping method, and without the need of vacuum-assisted filling or syringe pumps. The microwell array is aligned to a 96well plate format for automated fluorescent readouts. The cell culture surface area of each microwell is 5.7mm2 (5ul) and can accommodate 5,000-10,000 cells but the design of each microwell can be scale-down to accommodate smaller cell samples. The adjacent microwells are contained within an outer-ring of 8mm diameter and 750um height. After cell seeding, adjacent compartments can be connected by dispensing a volume of 30-40ul inside the outer ring. A model of tumor-mesenchyme paracrine Hedgehog signaling was developed and characterized to show the feasibility of this array for multi-cell soluble factor signaling studies. Activation of Hedgehog (Hh) signaling in the mesenchyme promotes proliferation of tumor cells via secreted factors. As a source of mesenchymal cell sub-types we evaluated TGF-b treated fibroblasts and tumor epithelial cells that undergo epithelial-mesenchymal transition. Myofibroblast phenotype was confirmed based on overexpression of smooth muscle actin, vimentin and fibroblast activating protein, and reduce levels of caveolin-1. Active Hh signaling and pharmacological inhibition with cyclopamine were confirmed by up- and down- regulation of canonical Hh target genes Gli1 and Patch1. Active hedgehog signaling and cell viability was maintained over 5-7days 2-dimensional and collagen type I embedded mesenchymal cells. Breast-derived human epithelial and mesenchymal cells co-cultured in microwells and transwells showed similar increase in tumor cell proliferation rates but with a reduction of 80% or more in the total cells needed compared to transwells. Flow cytometer read-outs of proliferation and tumor cell distribution of CD44/CD24 cell surface receptors were similar among transwells and microwells. Adjacent culture of mouse derived fibroblasts (NIH-3T3) and human tumor cells showed recovery of genomic sample without cell-population mixing using primers for specific for human and mouse GAPDH. Doubling of the number of microwells with mesenchymal cells modulated the observed proliferative effect in tumor cells suggesting that mesenchymal cell ratios modulate tumor response to paracrine Hh signaling. This observation could not be replicated in macro-scale platforms as active Hh signaling in the mesenchyme is achieved via cell growth arrest using a combination of low serum and cell confluence. The open multi-microwell array represents a new user-friendly multi-culture microscale array with optimized capabilities for the study of paracrine signaling among discrete cell populations compared to macroscale culture technology. Citation Format: Karla P. Ramos, Fernando Boria, Maribella Domenech. Open multi-microwell array for the study of paracrine signaling in tumors. [abstract]. In: Proceedings of the AACR Special Conference on Engineering and Physical Sciences in Oncology; 2016 Jun 25-28; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2017;77(2 Suppl):Abstract nr B02.

Effects of At2 Receptor Agonist Novokinin on Oxidative Stress, Inflammation and Infarct Size Due to Myocardial Ischemia-Reperfusion

Aim: Ischemia and reperfusion (IR) injury is a serious problem that is occured during thrombolytic therapy, organ transplantation, coronary angioplasty, and cardiopulmonary bypass. There is an increase in the number of AT2 receptors in some pathological conditions such as cardiac hypertrophy, myocardial infarction, congestive heart failure. This study was designed to investigate the effects AT2 receptor agonist Novokinin on infarct size, caveolin-1 (CAV-1), HSP90, ADMA, NADPH oxidase and Rhokinase associated to endothelial dysfunction and oxidative stress, and NFκB and TLR-4 levels induced by inflammation on myocardial IR. Methods: The experimental groups: Sham (C), Novokinin (N), IR and IRN. Novokinin was performed with infusion pump before ischemia, and during IR. The left main coronary artery was occluded for 30 minutes ischemia followed by 120 minutes reperfusion in anesthetized rats. CAV-1, HSP90, and NFκB levels were measured by the quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), ADMA, TLR-4, NADPH oxidase, and Rhokinase levels were measured by ELISA, infarct size was measured by ImageJ, an image analysis software, in the heart tissue. Results: NFκB, HSP90, NADPH oxidase and TLR-4 levels increased with IR and significantly decreased with Novokinin. CAV-1 levels were not different between the groups. ADMA and Rhokinase levels were increased due to IR but decreased with Novokinin. Novokinin reduced infarct size due to IR. Conclusion: Our results showed that, ADMA, HSP90, NFκB, TLR-4, Rhokinase, and NADPH oxidase levels play important roles on IR injury. AT2 receptor agonist Novokinin may affect positively oxidative changes, inflammation, and endothelial function in myocardial IR injury.

Is plasma caveolin-1 level a prognostic biomarker in metastatic pancreatic cancer?

Background/Aims:To evaluate the prognostic significance of plasma caveolin (CAV)-1 and its association with survival and treatment response rates in metastatic pancreatic cancer (MPC).Patients and Methods:Plasma samples were prospectively collected from 41 patients with newly diagnosed MPC. Moreover, plasma samples were collected from 48 patients with chronic pancreatitis and 41 healthy individuals (control groups) for assessing Cav-1 levels. Plasma Cav-1 levels were evaluated at baseline and after three cycles of chemotherapy in the patients with MPC.Results:The median Cav-1 level was 13.8 ng/mL for the patients with MPC and 12.2 ng/mL for healthy individuals (P = 0.009). The Cav-1 cut-off level was calculated as 11.6 ng/mL by using the receiver operating characteristic curve. The median overall survival and progression-free survival rates were 5 and 2.4 months, respectively, for participants with a high basal plasma Cav-1 level; the corresponding values were 10.5 and 9.4 months for participants with a low plasma Cav-1 level (P = 0.011 and P = 0.003, respectively). Of the 41 patients with MPC, 23 completed at least three cycles of chemotherapy. The median Cav-1 level was 13 ng/mL for post-treatment MPC (r2: 0.917; P = 0.001). High basal plasma caveolin-1 level have continued to remain at high levels even after chemotherapy, showing a trend toward worse response rates (P = 0.086).Conclusion:High basal plasma Cav-1 levels seem to be associated with poor survival and tend to yield worse therapeutic outcomes in patients with MPC. This study is the first to evaluate the prognostic significance of plasma Cav-1 levels as a prognostic factor in patients with MPC. However, larger prospective clinical trials are warranted.

Expression of Concern: Induction of nitric oxide synthase-2 proceeds with the concomitant downregulation of the endogenous caveolin levels. J. Cell Sci. doi:10.1242/jcs.01002.

This Expression of Concern relates to the article ‘Induction of nitric oxide synthase-2 proceeds with the concomitant downregulation of the endogenous caveolin levels’ by Inmaculada Navarro-Lerida, Maria Teresa Portoles, Alberto Alvarez Barrientos, Francisco Gavilanes, Lisardo Bosca and

The serum protein profile of early parity which induces protection against breast cancer

Early parity reduces the risk of breast cancer in women while nulliparity and late parity increase the risk of breast cancer. In order to translate this protection to women where early pregnancy is not feasible, much work has focused on understanding how parity confers protection against breast cancer, the molecular mechanisms by which this occurs is still not well understood. Healthy parous and nulliparous women were recruited for this study. We assessed serum protein profiles of early parous, late parous, and nulliparous women using the Phospho Explorer antibody array. Significantly altered proteins identified were validated by Western blot analysis. In silico analysis was performed with the data obtained. Our findings indicate increased phosphorylation levels of CDK1, AKT1 and Epo-R increased cell cycle and cell proliferation in late/nulliparous women. Increased levels of LIMK1, paxillin, caveolin-1, and tyrosine hydroxylase in late/nulliparous women demonstrate enhanced cell stress while decreased activity of p-p53 and pRAD51 in late/nulliparous women indicates decreased apoptosis and increased genomic instability. Further, increased levels of pFAK, pCD3zeta, pSTAT5B, MAP3K8 in early parous women favor enhanced innate/adaptive immunity. Overall, we have identified a unique protein signature that is responsible for the decreased risk of breast cancer and these proteins can also serve as biomarkers to predict the risk of breast cancer.

Alterations of caveolin-1 expression in a mouse model of delayed cerebral vasospasm following subarachnoid hemorrhage.

The aim of the present study was to evaluate the expression levels of caveolin-1 in the basilar artery following delayed cerebral vasospasm (DCVS) in a rat model of subarachnoid hemorrhage (SAH), in order to investigate the association between caveolin-1 and DCVS, and its potential as a treatment for DCVS of SAH. A total of 150 Sprague Dawley rats were randomly allocated into blank, saline and SAH groups. The SAH and saline groups were subdivided into days 3, 5, 7 and 14 following the establishment of the model. The murine model of SAH was established by double injection of autologous arterial blood into the cisterna magana and DCVS was detected using Bederson neurological severity scores. Hematoxylin and eosin (HE) staining was used to observe the inner perimeter of the basilar artery pipe and variations in the thickness of the basilar artery wall. Alterations in the levels of caveolin-1 protein in the basilar artery were measured using immunofluorescence and western blot analysis; whereas alterations in the mRNA expression levels of caveolin-1 were detected by reverse transcription-quantitative polymerase chain reaction. In the present study, 15 mice succumbed to SAH-induced DCVS in the day 3 (n=3), 5 (n=5) and 7 (n=2) groups. No mortality was observed in the blank control and saline groups during the process of observation in the SAH group, All mice in the SAH groups exhibited Bederson neurological severity scores ≥1; whereas no neurological impairment was detected in the blank and normal saline groups, demonstrating the success of the model. HE staining was used to assess vasospasm and the results demonstrated that the inner perimeter of the basal artery pipe decreased at day 3 in the SAH group; whereas values peaked in the day 7 group. The thickness of the basal artery wall significantly increased (P<0.05), as compared with the blank and saline groups, in which no significant alterations in the wall thickness and the inner perimeter of the basal artery pipe were detected. As detected by immunofluorescence and western blot analysis, the expression levels of caveolin-1 protein significantly decreased in the day 7 of SAH group, as compared with the blank and saline groups (P<0.01), in which no significant alterations were detected. Caveolin-1 mRNA expression levels significantly increased at the day 7 in the SAH group, as compared with the blank and the saline groups (P<0.01), as detected by RT-qPCR. Furthermore, significant differences were detected at day 14 in the SAH group, as compared with the blank and the saline groups (P>0.05), in which no significant alterations were detected. Therefore, the results of the present study demonstrated that caveolin-1 protein was downregulated in the basilar artery of a rat modeling SAH, which may be associated with DCVS. This suggested that caveolin-1 may be a potential target for the treatment of DCVS.

Caveolin-1, Ring finger protein 213, and endothelial function in Moyamoya disease.

Moyamoya disease is a unique cerebrovascular occlusive disease of unknown etiology. Ring finger protein 213 (RNF213) was identified as a susceptibility gene for Moyamoya disease in East Asian countries. However, the pathogenesis of Moyamoya disease remains unclear. We prospectively analyzed clinical data for 139 patients with Moyamoya disease (108 bilateral Moyamoya disease, 31 unilateral Moyamoya disease), 61 patients with intracranial atherosclerotic stroke, and 68 healthy subjects. We compared the genetic (RNF213 variant) and protein biomarkers for caveolae (caveolin-1), angiogenesis (vascular endothelial growth factor (VEGF) and receptor (VEGFR2), and antagonizing cytokine (endostatin)) and endothelial dysfunction (asymmetric dimethylarginine (ADMA), and nitric oxide and its metabolites (nitrite and nitrate)) between patients with Moyamoya disease and intracranial atherosclerotic stroke. We then performed path analysis to evaluate whether a certain protein biomarker mediates the association between genes and Moyamoya disease. Caveolin-1 level was decreased in patients with Moyamoya disease and markedly decreased in RNF213 variant carriers. Circulating factors such as VEGF and VEGFR2 did not differ among the groups. Markers for endothelial dysfunction were significantly higher in patients with intracranial atherosclerotic stroke but normal in those with Moyamoya disease. Path analysis showed that the presence of the RNF213 variant was associated with caveolin-1 levels that could lead to Moyamoya disease. The level of combined marker of Moyamoya disease (caveolin-1) and intracranial atherosclerotic stroke (ADMA, an endothelial dysfunction marker) predicted Moyamoya disease with good sensitivity and specificity. Our results suggest that Moyamoya disease is a caveolae disorder but is not related to endothelial dysfunction or dysregulation of circulating cytokines.

Caveolin-1 Mediates Low-Intensity Ultrasound-Induced Apoptosis via Downregulation of Signal Transducer and Activator of Transcription 3 Phosphorylation in Laryngeal Carcinoma Cells

Low-intensity ultrasound therapy has been found to be a potential tool in the management of malignant tumors in recent years. However, the molecular mechanism underlying low-intensity ultrasound-induced apoptosis is still not clear. In this study, we investigated the effects of low-intensity ultrasound-induced apoptosis in HEp-2 cells. We found that low-intensity ultrasound significantly induced apoptosis, and the expression level of caveolin-1 (Cav-1) was dramatically increased after ultrasound treatment of HEp-2 cells. After inhibiting the expression level of Cav-1 using siRNA transfection, we found that the cellular apoptosis induced by low-intensity ultrasound was significantly suppressed. In addition, inhibition of Cav-1 expression promoted phosphorylation of signal transducer and activator of transcription 3 (STAT3), suggesting that the STAT3 signaling pathway was involved in low-intensity ultrasound-induced apoptosis via Cav-1 regulation. Our results indicate that Cav-1/STAT3 signaling pathway may mediate low-intensity ultrasound-induced apoptosis, and this technology could potentially be used clinically for the treatment of cancers.

Plasma caveolin-1 level: A prognostic marker for pancreatic cancer.

e15706Background: Evaluation of the prognostic significance of plasma caveolin-1(cav1) and its relation with survival & response rates in metastatic pancreatic cancer(MPC). Methods: The patients fo...

Spatiotemporal expression of caveolin-1 and EMMPRIN during mouse tooth development.

Caveolin-1 is a scaffolding protein involved in the formation of cholesterol-rich caveolae lipid rafts within the plasma membrane and is capable of collecting signaling molecules into the caveolae and regulating their activity, including extracellular matrix metalloproteinase inducer (EMMPRIN). However, detailed expression patterns of caveolin-1 and EMMPRIN in the developing dental germ are largely unknown. The present study investigated the expression patterns of caveolin-1 and EMMPRIN in the developing mouse tooth germ by immunohistochemistry and real-time polymerase chain reaction. At the bud stage, caveolin-1 expression was initiated in the epithelium bud and mesenchymal cells, while EMMPRIN was weakly expressed at this stage. At the cap stage, caveolin-1 protein was located in the lingual part of the tooth germ; however, EMMPRIN protein was located in the labial part. From the bell stage to 2days postnatal, caveolin-1 expression was detected in the ameloblasts and cervical loop area; with EMMPRIN expression in the ameloblasts and odontoblasts. Real-time polymerase chain reaction results showed that both caveolin-1 and EMMPRIN mRNA levels increased gradually with progression of developmental stages, and peaked at day two postnatal. The current finding suggests that both caveolin-1 and EMMPRIN take part in mouse tooth development, especially in the differentiation and organization of odontogenic tissues.

Tu2072 The Changes of Expression Levels of Caveolin-1 in Tumor Microenvironment Promote the Proliferation of Gastric Cancer Cells

Tu2072 The Changes of Expression Levels of Caveolin-1 in Tumor Microenvironment Promote the Proliferation of Gastric Cancer Cells

DT(270-326) , a Truncated Diphtheria Toxin, Increases Blood-Tumor Barrier Permeability by Upregulating the Expression of Caveolin-1.

The nontoxic mutant of diphtheria toxin (DT) has been demonstrated to act as a receptor-specific carrier protein to delivery drug into brain. Recent research showed that the truncated "receptorless" DT was still capable of being internalized into cells. This study investigated the effects and potential mechanisms of DT(270-326) , a truncated "receptorless" DT, on the permeability of the blood-tumor barrier (BTB). BTB and GECs were subjected to DT(270-326) treatment. HRP flux assays, immunofluorescent, co-immunoprecipitation, Western blot, CCK-8, and Flow cytometry analysis were used to evaluate the effects of DT(270-326) administration. Our results revealed that 5 μM of DT(270-326) significantly increased the permeability of BTBin vitro, which reached its peak at 6 h. The permeability was reduced by pretreatment with filipinIII. DT(270-326) co-localized and interacted with caveolin-1 via its caveolin-binding motif. The mRNA and protein expression levels of caveolin-1 were identical with the changes of BTB permeability. The upregulated expression of caveolin-1 was associated with Src kinase-dependent tyrosine phosphorylation of caveolin-1, which subsequently induced phosphorylation and inactivation of the transcription factor Egr-1. The combination of DT(270-326) with doxorubicin significantly enhanced the loss of cell viability and apoptosis of U87 glioma cells in contrast to doxorubicin alone. DT(270-326) might provide a novel strategy to increase the delivery of macromolecular therapeutic agents across the BTB.

Abstract WP280: Caveolin-1, Ring Finger Protein 213, and Endothelial Function in Moyamoya Disease

Background: Moyamoya disease (MMD) is a unique cerebrovascular occlusive disease of unknown etiology. Ring finger protein 213 (RNF213) was identified as a susceptibility gene for MMD in East Asian. However, the pathogenesis of MMD is still unclear. Methods: We prospectively analyzed clinical data for 139 patients with MMD (108 definite MMD, 31 probable MMD) and 61 patients with intracranial atherosclerotic stroke (ICAS), and 68 healthy subjects. We compared the genetic (RNF213 variant) and protein biomarkers for caveolae (caveolin-1), angiogenesis (vascular endothelial growth factor [VEGF] and receptor [VEGFR2], and antagonizing cytokine [endostatin]) and endothelial dysfunction (asymmetric dimethylarginine [ADMA], nitric oxide and its metabolites [nitrite and nitrate]), between patients with MMD and ICAS. We then performed the path analysis to evaluate whether a certain protein biomarker mediates the association the genetic and MMD. Results: Caveolin-1 level was decreased in patients with MMD and this level was markedly decreased in RNF213 variant carriers. Circulating factor such as VEGF and receptor were not different among the groups. Markers for endothelial dysfunction were significantly higher in patients with ICAS, but normal in MMD. The path analysis showed that the presence of the RNF213 variant was associated with caveolin-1 level that led to MMD. The level of combined marker of MMD (caveolin-1) and ICAS (ADMA, marker for endothelial dysfunction) predicted MMD with a good sensitivity and specificity. Conclusions: Our results indicate that MMD is primarily caveolae disorder, dysregulation of endothelial vesicular trafficking and signal transduction, but not related to endothelial dysfunction or dysregulation of circulating cytokines.

Is Serum Caveolin-1 a Useful Biomarker for Progression in Patients with Colorectal Cancer?.

Colorectal cancer (CRC) is the third most common cause of cancer diagnosed in males and the second in females. Survival is strongly related to stage at diagnosis. There is an urgent need to find a noninvasive biomarker that can be commonly applied for screening diagnosis, early detection of recurrence, and monitoring of metastatic CRC. Protein caveolin-1 (CAV-1) has been known to be expressed abnormally in colon cancer and appears to contribute to aberrant signaling and protein trafficking. There are controversial results regarding the role of CAV-1 in cancer. We hypothesized that levels of CAV-1 in serum of patients with CRC might be important to estimate the progression of the disease. Therefore, the purpose of this study is to investigate whether serum CAV-1 might be used as a factor determining progression of CRC. A total of 61 patients with CRC (26 male, 35 female) and 46 controls (38 male, 8 female) were enrolled. Serum CAV-1 levels were measured by ELISA. The relationship between CAV-1 and progression-free survival (PFS) was analyzed with use of receiver operating characteristic (ROC) and Kaplan-Meier analysis. Results were given as median (95% CI). Mann-Whitney test was used for the comparison of groups. CAV-1 levels were found to be 11.5 ng/mL (10.4-12.9) in CRC and 11.9 ng/mL (10.7-14.4) in controls (p = 0.465). The serum CAV-1 levels in CRC patients with disease progression and without progression were respectively 10.0 ng/mL (8.5-11.3) and 12.2 ng/mL (11.1-14.8) (p = 0.023). In ROC analysis, if CAV-1 levels are equal or lesser than 10.73 ng/mL, it might show presence of progression with a sensitivity 73.3% and specificity 66.7% in patients with CRC (area under the ROC curve (AUC) = 0.697, p = 0.005). The mean PFS time was found to be 29.7 months (19.8-39.7, 95% CI for the mean) in patients who have CAV-1 level ≤ 10.73 ng/mL and 61.9 months (44.2-79.6) in patients who have CAV-1 level > 10.73 ng/mL [hazard ratios (HR) with 95% CI = 3.49 (1.26 - 9.68) (p = 0.017)]. Our results strongly suggest that CAV-1 levels might be used as a marker to determine progression of CRC. When considered in combination with other biomarkers of CRC, CAV-1 is clinically informative and instructive.