Expression of phosphorylated p21-activated kinase 4 is associated with aggressive histologic characteristics and poor prognosis in patients with surgically treated renal cell carcinoma

Purpose

P21-activated kinase 4 (PAK4), a serine/threonine kinase that regulates a number of fundamental cellular processes, has been suggested as a prognostic factor for various human tumors. The aim of the present study was to evaluate the clinical implications of phospho-Ser474 PAK4 (pPAK4^S474), an activated form of PAK4, in surgically treated renal cell carcinoma (RCC).

Materials and Methods

Samples from 131 patients with surgically treated RCC were immunostained to detect PAK4 and pPAK4^S474. Expression of PAK4 and pPAK4^S474 was compared with clinicopathological characteristics and survival after nephrectomy.

Results

PAK4 and pPAK4^S474 were expressed predominantly in the nucleus. Overall, 57.3% (75/131) and 24.4% (29/119) of specimens exhibited high expression of pPAK4^S474 and PAK4, respectively. High expression of pPAK4^S474 was associated with adverse pathologic characteristics, including advanced tumor stage and grade (p=0.036 and p=0.002, respectively), whereas this association was not significant for PAK4 expression (each p>0.05). Kaplan-Meier estimates showed that high expression of pPAK4^S474 was associated with shorter recurrence-free survival in a subgroup with localized RCC and with cancer-specific survival in the total RCC cohort (log-rank test: p=0.001 and p=0.005, respectively), whereas PAK4 expression was not. Multivariate Cox regression analysis identified that high pPAK4^S474 expression was an independent predictor of recurrence in the subgroup with localized RCC.

Conclusions

pPAK4^S474 may be a more accurate prognostic factor than total PAK4 in RCC patients. This marker would be useful for identifying patients with pathologically localized disease who may require further interventions.

Implant survival and risk factor analysis in regenerated bone: results from a 5-year retrospective study

Purpose

The aims of this study were to evaluate the 5-year cumulative survival rate (CSR) of implants placed with guided bone regeneration (GBR) compared to implants placed in native bone, and to identify factors contributing to implant failure in regenerated bone.

Methods

This retrospective cohort study included 240 patients who had implant placement either with a GBR procedure (regenerated bone group) or with pristine bone (native bone group). Data on demographic features (age, sex, smoking, and medical history), location of the implant, implant-specific features, and grafting procedures and materials were collected. The 5-year CSRs in both groups were estimated using Kaplan-Meier analysis. Risk factors for implant failure were analyzed with a Cox proportional hazards model.

Results

In total, 264 implants in the native bone group and 133 implants in the regenerated bone group were analyzed. The 5-year CSRs were 96.4% in the regenerated bone group and 97.5% in the native bone group, which was not a significant difference. The multivariable analysis confirmed that bone status was not an independent risk factor for implant failure. However, smoking significantly increased the failure rate (hazard ratio, 10.7; P=0.002).

Conclusions

The 5-year CSR of implants placed in regenerated bone using GBR was comparable to that of implants placed in native bone. Smoking significantly increased the risk of implant failure in both groups.

Antiangiogenesis Effect of Albendazole on the Cornea

Purpose: To investigate the anti-(lymph)angiogenic and anti-inflammatory effects of albendazole and to study whether these effects are additive with bevacizumab therapy in a murine corneal suture model. Methods: Corneal neovascularization (NV) and lymphangiogenesis (LY) were compared in a corneal suture model after administration of a subconjunctival injection of albendazole, bevacizumab, dexamethasone, or phosphate-buffered saline (PBS). Immunohistochemical staining and analysis were performed in each group. Real-time polymerase chain reaction (RT-PCR) was performed to quantify the expression of inflammatory cytokines (tumor necrosis factor [TNF]-alpha and interleukin-6), vascular endothelial growth factor (VEGF)-A, VEGF-C, vascular endothelial growth factor receptor (VEGFR)-2, and VEGFR-3. To evaluate the additive effect of albendazole, corneal NV and LY were also analyzed in a combined group of albendazole and bevacizumab therapy and the additive effect was compared with that in the group of double dose of bevacizumab. Results: The albendazole group showed less NV and less LY compared with the PBS control group (P < 0.01). When albendazole was combined with bevacizumab therapy, a significant decrease in NV and LY was seen compared with bevacizumab treatment alone, and with albendazole alone (all P values <0.05). The combination group showed better antilymphangiogenesis effect than the group of double dose bevacizumab. The albendazole-treated group showed reduced expression of VEGF-A, VEGF-C, TNF-alpha, and VEGFR-2 compared with corneas from the PBS group (P value <0.05 in all respective comparisons). Conclusion: Albendazole significantly decreased NV and LY in the cornea. This beneficial effect is additively enhanced when combined with bevacizumab treatment.

In Vitro Derivation of Functional Sertoli-Like Cells from Mouse Embryonic Stem Cells

Sertoli cells (SCs) in the mammalian testes are well known as supporting cells of spermatogenesis, but have recently become an attractive source of cell therapy because of their capacity for immune modulation and trophic effects. In order to increase their applicable efficacy, we demonstrate a novel differentiation method for mouse embryonic stem cell (ESC)-derived Sertoli-like cells (SLCs) via the intermediate mesoderm (IM). We show that IM derived from an induction of 6 days expressed markers such as Wt1, Lhx1, Pax2 and Osr1, and that a sequential induction of 6 days resulted in ESC-SLCs. The SLCs expressed their marker genes ( Sf1, Sox9, Gata4, Wt1, Fshr and Scf), but the pluripotency-marker gene Oct4 was decreased. After sorting by FSHR expression, high-purity (> 90%) SLCs were collected that showed distinct characteristics of SCs such as high phagocytic and immune modulation activities as well as the expression of immune-related genes. In addition, when transplanted into the seminiferous tubule of busulfan-treated mice, SLCs re-located and were maintained in the basal region of the tubule. These results demonstrated that our robust sequential differentiation system produced functional SLCs from mouse ESCs in vitro.

The Effect of 0.5% Timolol Maleate on Corneal(Lymph)Angiogenesis in a Murine Suture Model

PURPOSE

To investigate the anti(lymph)angiogenic and anti-inflammatory effects of 0.5% timolol maleate in a murine corneal suture model.

METHODS

Corneal neovascularization and lymphangiogenesis were compared in groups of mice that underwent corneal suture and were subsequently administered a subconjunctival injection of 0.5% timolol maleate, dexamethasone, or phosphate-buffered saline (PBS). Immunohistochemical staining and analysis were performed in each group. Real-time polymerase chain reaction (RT-PCR) was performed to quantify the expression of inflammatory cytokines [TNF-alpha and interleukin (IL)-6], vascular endothelial growth factor (VEGF)-A, VEGF-C, vascular endothelial growth factor receptor (VEGFR)-2, and VEGFR-3.

RESULTS

When corneas from the timolol-treated group were compared to the PBS-treated group, we observed decreases in angiogenesis, lymphangiogenesis, and inflammatory infiltration in the timolol-treated group (P value <0.05 in all respective comparisons). Corneas from the timolol-treated group showed reduced expression of VEGF-A, VEGF-C, TNF-alpha, IL-6, VEGFR-2, and VEGFR-3 compared to corneas from the PBS group (P value <0.05 in all respective comparisons).

CONCLUSION

Blocking adrenergic signaling in the cornea with 0.5% timolol maleate decreased corneal neovascularization and lymphangiogenesis.

Astrocytic water channel aquaporin-4 modulates brain plasticity in both mice and humans: a potential gliogenetic mechanism underlying language-associated learning

The role of astrocytes in brain plasticity has not been extensively studied compared with that of neurons. Here we adopted integrative translational and reverse-translational approaches to explore the role of an astrocyte-specific major water channel in the brain, aquaporin-4 (AQP4), in brain plasticity and learning. We initially identified the most prevalent genetic variant of AQP4 (single nucleotide polymorphism of rs162008 with C or T variation, which has a minor allele frequency of 0.21) from a human database (n=60 706) and examined its functionality in modulating the expression level of AQP4 in an in vitro luciferase reporter assay. In the following experiments, AQP4 knock-down in mice not only impaired hippocampal volumetric plasticity after exposure to enriched environment but also caused loss of long-term potentiation after theta-burst stimulation. In humans, there was a cross-sectional association of rs162008 with gray matter (GM) volume variation in cortices, including the vicinity of the Perisylvian heteromodal language area (Sample 1, n=650). GM volume variation in these brain regions was positively associated with the semantic verbal fluency. In a prospective follow-up study (Sample 2, n=45), the effects of an intensive 5-week foreign language (English) learning experience on regional GM volume increase were modulated by this AQP4 variant, which was also associated with verbal learning capacity change. We then delineated in mice mechanisms that included AQP4-dependent transient astrocytic volume changes and astrocytic structural elaboration. We believe our study provides the first integrative evidence for a gliogenetic basis that involves AQP4, underlying language-associated brain plasticity.

Effect of itraconazole on the cornea in a murine suture model and penetrating keratoplasty model

AIM

To investigate the anti-(lymph)angiogenic and/or anti-inflammatory effect of itraconazole in a corneal suture model and penetrating keratoplasty (PK) model.

METHODS

Graft survival, corneal neovascularization, and corneal lymphangiogenesis were compared among itraconazole, amphotericin B, dexamethasone, phosphate buffered saline (PBS) and surgery-only groups following subconjunctival injection in mice that underwent PK and corneal suture. Immunohistochemical staining and analysis were performed in each group. Real-time polymerase chain reaction (RT-PCR) was performed to quantify the expression of inflammatory cytokines (TNF-alpha, IL-6) and vascular endothelial growth factor (VEGF)-A, VEGF-C, VEGFR-2, and VEGFR-3.

RESULTS

In the suture model, the itraconazole group showed less angiogenesis, less lymphangiogenesis, and less inflammatory infiltration than the PBS group (all P<0.05). The itraconazole group showed reduced expression of VEGF-A, VEGFR-2, TNF-alpha, IL-6 than the PBS group (all P<0.05). In PK model, the two-month graft survival rate was 28.57% in itraconazole group, 62.50% in dexamethasone group, 12.50% in PBS group, 0 in amphotericin B group and 0 in surgery-only group. Graft survival in the itraconazole group was higher than that in the amphotericin, PBS and surgery-only group (P=0.057, 0.096, 0.012, respectively). The itraconazole group showed less total angiogenesis and lymphangiogenesis than PBS group (all P<0.05).

CONCLUSION

Itraconazole decrease neovascularization, lymphangiogenesis, and inflammation in both a corneal suture model and PK model. Itraconazole has anti-(lymph)-angiogenic and anti-inflammatory effects in addition to its intrinsic antifungal effect and is therefore an alternative treatment option in cases where steroids cannot be used.

Anticancer Effects of Colchicine on Hypopharyngeal Cancer

Colchicine is an alkaloid widely used for the treatment of inflammatory diseases, such as gout. It suppresses cell division by inhibiting mitosis. We investigated the anticancer effects of colchicine on human hypopharyngeal cancer cells and the mechanisms underlying its anticancer effects. XTT cell proliferation assay showed that colchicine inhibited the growth and proliferation of human hypopharyngeal cancer cells (FaDu and SNU1041) in a dose- and time-dependent manner. Colchicine also inhibited the migration, invasion, and adhesion of hypopharyngeal cancer cells in a dose-dependent manner. The levels of mRNA expression and activity of matrix metalloproteinase-9 (MMP9) and urokinase-type plasminogen activator (uPA) decreased after treatment with colchicine. Further investigation revealed that colchicine inhibited the phosphorylation of the FAK/SRC complex and paxillin. Tumor volume ratios in colchicine-treated mice (0.1 mg/kg, every 2 days for 14 days) increased less than in control mice. To our knowledge, this is the first report showing that colchicine can suppress cell invasion, migration, and adhesion through reduced expression of MMP9, the uPA system, and the FAK/SRC complex. Colchicine has the potential to prevent disease progression in hypopharyngeal cancer and may have application as an adjunctive treatment.

Effect of sorafenib in a murine high risk penetrating keratoplasty model

AIM

To evaluate the effect of sorafenib in murine high risk keratoplasty model.

METHODS

Graft survival, corneal neovascularization, and corneal lymphangiogenesis were compared among the sorafenib, dexamethasone, dimethyl sulfoxide (DMSO), and phosphate buffered saline (PBS) groups following subconjunctival injection in mice that underwent high risk penetrating keratoplasty (HRPK). Real-time polymerase chain reaction was performed to quantify the expression of inflammatory cytokines and vascular endothelial growth factor (VEGF)-A, VEGF-C, vascular endothelial growth factor receptor (VEGFR)-2, VEGFR-3.

RESULTS

The two-month graft survival rate for HRPK was 42.86% in sorafenib group, 37.50% in dexamethasone group, 0 in DMSO group, and 0 in PBS group. Sorafenib significantly increased graft survival compared to the DMSO and PBS group (P<0.05). The sorafenib didn't show significant effect in decreasing neovascularization compared with dexamethsone, DMSO, and PBS group. The sorafenib showed less total lymphangiogenesis than the dexamethasone, DMSO, and PBS group (P=0.011, P<0.001, P<0.001, respectively). The sorafenib group showed reduced expression of VEGF-C, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, VEGFR-2 and VEGFR-3 compared with DMSO group and PBS group (all P<0.05). The sorafenib group didn't show difference in the expression of VEGF-A compared with DMSO, neither with PBS. The sorafenib group showed reduced expression of VEGFR-3 compared with dexamethasone (P=0.051).

CONCLUSION

The subconjunctivally administered sorafenib shows significant anti-lymphangiogenic effect, resulting in increased transplant survival in a murine high risk keratoplasty model. We suggest that a close linkage between decreased VEGF-C/VEGFR-2 and -3 signaling and increased corneal graft survival by sorafenib seems to exist.

[Hospital Arrival Rate within Golden Time and Factors Influencing Prehospital Delays among Patients with Acute Myocardial Infarction]

PURPOSE

This research was done to identify the hospital arrival rate and factors related to prehospital delay in arriving at an emergency medical center within the golden time after symptom onset in patients with acute myocardial infarction (AMI).

METHODS

Data used in the research was from the National Emergency Department Information System of the National Emergency Medical Center which reported that in 2014, 9,611 patients went to emergency medical centers for acute myocardial infarction. Prehospital time is the time from onset to arrival at an emergency medical center and is analyzed by subdividing arrival and delay based on golden time of 2 hour.

RESULTS

After onset of acute myocardial infarction, arrival rate to emergency medical centers within the golden time was 44.0%(4,233), and factors related to prehospital delay were gender, age, region of residence, symptoms, path to hospital visit, and method of transportation.

CONCLUSION

Results of this study show that in 2014 more than half of AMI patients arrive at emergency medical centers after the golden time for proper treatment of AMI. In order to reduce prehospital delay, new policy that reflects factors influencing prehospital delay should be developed. Especially, public campaigns and education to provide information on AMI initial symptoms and to enhance utilizing EMS to get to the emergency medical center driectly should be implemented for patients and/or caregivers.

Effect of trapping vascular endothelial growth factor-A in a murine model of dry eye with inflammatory neovascularization

AIM

To evaluate whether trapping vascular endothelial growth factor A (VEGF-A) would suppress angiogenesis and inflammation in dry eye corneas in a murine corneal suture model.

METHODS

We established two groups of animals, one with non-dry eyes and the other with induced dry eyes. In both groups, a corneal suture model was used to induce inflammation and neovascularization. Each of two groups was again divided into three subgroups according to the treatment; subgroup I (aflibercept), subgroup II (dexamethasone) and subgroup III (phosphate buffered saline, PBS). Corneas were harvested and immunohistochemical staining was performed to compare the extents of neovascularization and CD11b+ cell infiltration. Real-time polymerase chain reaction was performed to quantify the expression of inflammatory cytokines and VEGF-A in the corneas.

RESULTS

Trapping VEGF-A with aflibercept resulted in significantly decreased angiogenesis and inflammation compared with the dexamethasone and PBS treatments in the dry eye corneas (all P<0.05), but with no such effects in non-dry eyes. The anti-inflammatory and anti-angiogenic effects of VEGF-A trapping were stronger than those of dexamethasone in both dry eye and non-dry eye corneas (all P<0.05). The levels of RNA expression of VEGF-A, TNF-alpha, and IL-6 in the aflibercept subgroup were significantly decreased compared with those in the PBS subgroup in the dry eye group.

CONCLUSION

Compared with non-dry eye corneas, dry eye corneas have greater amounts of inflammation and neovascularization and also have a more robust response to anti-inflammatory and anti-angiogenic agents after ocular surface surgery. Trapping VEGF-A is effective in decreasing both angiogenesis and inflammation in dry eye corneas after ocular surface surgery.

Colloidal Preparation of γ-Fe2O3@Au [core@shell] Nanoparticles

γ-Fe2O3@Au core-shell nanoparticles were prepared through a combined route, in which high temperature organic solution synthesis and colloidal microemulsion techniques were successively applied. High magnification of TEM reveals the core-shell structure. The presence of Au on the surface of as-prepared particles is also confirmed by UV-Vis absorption. The magnetic core-shell nanoparticles offer a promising application in bio- and medical systems.

Involvement of betaPIX in angiotensin II-induced migration of vascular smooth muscle cells

Angiotensin II (Ang II) stimulates migration of vascular smooth muscle cell (VSMC) in addition to its contribution to contraction and hypertrophy. It is well established that Rho GTPases regulate cellular contractility and migration by reorganizing the actin cytoskeleton. Ang II activates Rac1 GTPase, but its upstream guanine nucleotide exchange factor (GEF) remains elusive. Here, we show that Ang II-induced VSMC migration occurs in a betaPIX GEF-dependent manner. betaPIX-specific siRNA treatment significantly inhibited Ang II-induced VSMC migration. Ang II activated the catalytic activity of betaPIX towards Rac1 in dose- and time-dependent manners. Activity reached a peak at 10 min and declined close to a basal level by 30 min following stimulation. Pharmacological inhibition with specific kinase inhibitors revealed the participation of protein kinase C, Src family kinase, and phosphatidylinositol 3-kinase (PI3-K) upstream of betaPIX. Both p21-activated kinase and reactive oxygen species played key roles in cytoskeletal reorganization downstream of betaPIX-Rac1. Taken together, our results suggest that betaPIX is involved in Ang II-induced VSMC migration.

Lidocaine attenuates the expression of ERK1/2 and CREB in a neuropathic pain model of rats

BACKGROUND

In addition to causing the loss of voluntary sensory and motor function, spinal cord injury (SCI) often creates a state of central neuropathic pain. Rats given SCI display increases in the activated form of transcription factors ERK 1/2, p38 MAPK, and CREB in the spinal cord, which correspond to allodynia in a model of neuropathic pain. The current study was designed to determine if lidocaine had an effect on the development of neuropathic pain in response to SCI.

METHODS

Male Sprague Dawley rats were anesthetized and then received a L5-L6 spinal nerve ligation (neuropathic rats). The levels of intracellular cell-signaling protein, ERK 1/2 and CREB were then assessed by western blot analysis of samples collected from a sham operated (control) group, a neuropathic pain and normal saline (NP + NS) group, and a neuropathic pain and 5% lidocaine (NP + Lido) group.

RESULTS

The increased levels of ERK 1/2 and CREB protein that were observed in the neuropathic pain model were reduced by continuous infusion of 5% lidocaine.

CONCLUSIONS

The current results suggest that lidocaine therapy may be an effective method of preventing and treating central neuropathic pain following SCI, and that these effects may occur via the reduced expression of ERK 1/2 and CREB in the intracellular cell-signaling pathway.

Clusterin confers paclitaxel resistance in cervical cancer

OBJECTIVE

To measure clusterin expression in cervical cancer tissues and cell lines and to evaluate whether clusterin confers resistance to paclitaxel in cervical cancer cells.

METHODS

Immunohistochemical staining for clusterin was performed on 15 normal cervical tissues and 32 primary cervical cancer tissues, and clusterin expression in cervical cancer cell lines was quantified by Western blotting. The correlation between clusterin expression level and paclitaxel IC50 in cervical cancer cell lines was evaluated. The effect of clusterin siRNA on paclitaxel resistance was evaluated by XTT assays.

RESULTS

Cervical cancer tissues expressed significantly higher levels of clusterin than did normal cervical tissues (4.08 vs. 1.35, P<0.05). Clusterin expression levels were correlated with paclitaxel resistance in cervical cancer cell lines, and transfection of clusterin siRNA into HeLaS3 cells significantly decreased their resistance to paclitaxel (P<0.05).

CONCLUSION

Our finding that clusterin expression was significantly higher in cervical cancer than in normal cervical tissues suggests that clusterin may confer paclitaxel resistance in cervical cancer cells.

bPAK-interacting exchange factor may regulate actin cytoskeleton through interaction with actin

p21-activated kinase (PAK)-interacting exchange factor (PIX) is known to be involved in regulation of Cdc42/Rac GTPases and PAK activity. PIX binds to the proline-rich region of PAK, and regulates biological events through activation of Cdc42/Rac GTPase. To further investigate the role of PIX we produced monoclonal antibodies (Mab) against bPIX. Three clones; N-C6 against N-terminal half and C-A3 and C-B7 against C- terminal half of bPIX were generated and characterized. N-C6 Mab detected bPIX as a major band in most cell lines. C-A3 Mab recognizes GIT-binding domain (GBD), but it does not interfere with GIT binding to bPIX. Using C-A3 Mab possible bPIX interaction with actin in PC12 cells was examined. bPIX Mab (C-A3) specifically precipitated actin of the PC12 cell lysates whereas actin Mab failed to immunoprecipitate bPIX. Co-sedimentation of PC12 cell lysates with the polymerized F-actin resulted in the recovery of most of bPIX in the cell lysates. These results suggest that bPIX may not interact with soluble actin but with polymerized F-actin and revealed that bPIX constitutes a functional complex with actin. These data indicate real usefulness of the bPIX Mab in the study of bPIX role(s) in regulation of actin cyoskeleton.

Synthesis and PTP1B inhibition of 1,2-naphthoquinone derivatives as potent anti-diabetic agents

A new series of 1,2-naphthoquinone derivatives was synthesized by various synthetic methods and evaluated for their ability to inhibit protein tyrosine phosphatase 1B (PTP1B). 1,2-Naphthoquinone derivatives with substituent at R(4) position showed submicromolar inhibitory activity, and compound 24 demonstrated 10- to 60-fold selectivity against the tested phosphatases. Also, several 4-aryl-1,2-naphthoquinone derivatives with substituents at R(3), R(6), R(7), or/and R(8) showed submicromolar inhibitory activity and good plasma stability.

c-Jun N-terminal kinase is involved in motility of endothelial cell

Cell motility is essential for a wide range of cellular activities including anigogenesis as well as metastasis of tumor cells. Ras has been implicated in cell migration and invasion, and functions at upstream of mitogen-activated protein kinase (MAPK) families, which include extracellular-signal regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 MAPK. In the present study, we examined the role of JNK in endothelial cell motility using stable transfectant (DAR-ECV) of ECV304 endothelial cells expressing previously established oncogenic H-Ras (leu 61). DAR-ECV cells showed an enhanced angiogenic potential and motility (approximately 2-fold) compared to ECV304 cells. Western blot analysis revealed constitutive activation of JNK in DAR-ECV cells. Pretreatment of JNK specific inhibitors, curcumin and all trans-retinoic acid, decreased the basal motility of DAR-ECV cells in a dose-dependent manner. These inhibitors also suppressed the motility stimulated by known JNK agonists such as TNFalpha and anisomycin. To further confirm the role of JNK, ECV304 cells expressing dominant active SEK1 (DAS-ECV) were generated. Basal non-stimulated levels of the cellular migration were greater in DAS-ECV clones than those in control ECV304 cells. These results suggest that Ras-SEK1-JNK pathway regulates motility of endothelial cells during angiogenesis.

Involvement of phospholipase D in oxidative stress-induced necrosis of vascular smooth muscle cells

Phospholipase D (PLD) has been associated with necrosis. However, it is not clear whether PLD plays a causative role in this cellular process. We investigated the role of PLD in oxidative stress-induced necrosis of vascular smooth muscle cells (VSMCs). Pervanadate (hydrogen peroxide plus orthovanadate) but not hydrogen peroxide alone activated PLD in a dose- and time-dependent manner. Exposure of VSMCs to pervanadate resulted in necrosis. Pretreatment with butan-1-ol, a PLD inhibitor, attenuated both pervanadate-induced necrosis and increase of intracellular Ca(2+). Removal of extracellular Ca(2+) inhibited pervanadate-induced necrosis by 50%. These results suggest that PLD activation mediates pervanadate-induced necrosis of VSMCs, which is at least partly due to Ca(2+) toxicity.

Production and characterization of monoclonal antibodies against amphiphysins

Amphiphysin I and II, proteins enriched in nerve terminals, form heterodimers and interact with dynamin and synaptojanin through their Src homology 3 (SH3) domain. In order to study the expression profile of Amphs in cells and tissues and the interaction state with other cellular molecules, we have prepared specific monoclonal antibodies (mAbs) designed to bait N-terminus, middle part, and C-terminus domains of Amph I, respectively by immunizing with the expressed smaller domain molecules using the GST gene fusion system. The expression of Amphs was found to be most abundant in PC12 cells, followed by B103 cells and vascular smooth muscle cells. Western blot analysis showed a relatively high level expression of Amphs that were found in both mouse and rat brain. There appeared to be some species difference in the expression pattern, i.e. Amphs are present more in the testis than in the lungs in rats, however, they are reversed in mice. Characterization of the mAbs revealed that clone 14-23 precipitated Amph I and II, whereas clone 8-2 could only precipitate Amph I. In addition, clathrin and dynamin in a complex with Amph were captured in the precipitate formed by mAbs and identified by the Western blot analysis. Cellular distribution of Amph was visualized with confocal immunofluorescence microscopy performed using the labeled-mAbs. Taken together, these results demonstrated that mAbs provided an excellent measure for studying Amphs' expression profile and their interacting proteins.

Up-regulation and co-expression of fibroblast growth factor receptors in human gastric cancer

Fibroblast growth factor (FGF), a key regulatory factor of cell growth and differentiation, is involved in embryonic development, angiogenesis, and tumorigenesis. To date, four different FGF receptors (FGFRs) have been cloned and characterized. We examined the expression of four FGFRs in human gastric cancer tissues and cell lines using Northern analysis, ribonuclease protection assay, and immunohistochemistry. The mRNAs of FGFR-1 (10/14), FGFR-2 (9/14), and FGFR-4 (9/14) were up-regulated in cancer compared with normal tissues. FGFR-3 mRNAs were barely detectable in both normal and cancer tissues. These FGFR mRNAs were co-expressed in various combinations of two or three in the same tissue. Immunohistochemistry confirmed specific staining of multiple FGFRs, except FGFR-3, in the cancer specimens. To investigate the functional significance of FGFR co-expression we examined the invasive property of SNU-16 cells, which exhibited gene amplification of FGFR-2, -3, and -4 as well as over-expression of keratinocyte growth factor receptor (KGFR), a splice variant of FGFR-2, and FGFR-4 mRNA. KGF plus acidic FGF (aFGF), KGF, and aFGF treatment enhanced the invasive potential of SNU-16 cells over the control by 100%, 107%, and 47%, respectively, indicating that neither additive nor synergistic effect was induced by stimulation with aFGF plus KGF. These results suggest that co-expression of FGFRs in various combinations may cause subtle changes in the progression of gastric cancer.

Enhancing effects of fatty acids on piroxicam permeation through rat skins

To increase the skin permeation of piroxicam from the Poloxamer 407 gel, fatty acid was added as a penetration enhancer to the Poloxamer 407 gel containing 1% piroxicam. The enhancing effects of the enhancer on the skin permeation of piroxicam were evaluated using Franz diffusion cells fitted with intact excised rat skins. To elucidate the modes of the action of enhancers, thermal analysis and histological examinations were conducted. Among fatty acids tested, linoleic acid showed the highest enhancing effects, with an enhancement factor (EF) of 1.76. From the thermal analysis results, fatty acids have fluidizing effects on the stratum corneum. The skin pretreated with the Poloxamer 407 gels containing piroxicam including linoleic acid showed a loosely layered stratum corneum and wide intercellular space.

Expression of SET is modulated as a function of cell proliferation

We explored a biological role of SET as it relates to cell proliferation and differentiation. Immunohistochemical staining demonstrated that the expression of SET was ubiquitous and diffuse over the whole embryo on gestational day 15. At a later stage of development, SET was expressed at relatively lower levels and localized to specific tissues and cells. On embryonic day 19, specific SET immunoreactivity was found in the epithelium of skin, respiratory tract, intestine, and retina as well as in muscle and cartilage. In these cells SET was stained mostly in the nucleus, which was supported indirectly by nuclear transport of enhanced green fluorescence protein-SET fusion proteins in ECV304 endothelial cells. Set mRNA expression was further confirmed in various cultured cells, including NIH 3T3 cells, L6 myoblast cells, human umbilical vein endothelial cells, and ECV304 cells. Using F9 teratocarcinoma cell lines, which were stimulated to differentiate into the two different cell lineages of parietal and visceral endoderm, we have further examined the role of SET. The expression of set mRNA and SET protein was diminished about three-fold in both differentiated endoderm cells compared to the undifferentiated F9 cells. However, when F9 cells were subjected to serum starvation, reduction of set mRNA abundance also took place at a similar level to that observed in response to differentiation. Consistent with this, quiescent L6 myoblast showed a marked downregulation of set mRNA compared to proliferating cells. These results suggest that SET is involved mainly in the regulation of cell proliferation rather than differentiation during embryonic development.

Overexpressed alpha3beta1 and constitutively activated extracellular signal-regulated kinase modulate the angiogenic properties of ECV304 cells

ECV304, a spontaneously transformed cell line derived from the human umbilical vein endothelial cell (HUVEC) (Takahashi et al., 1990), has been developed as an in vitro angiogenesis model. In the present study, we further characterized the angiogenic properties of this cell line. Compared to HUVEC, ECV304 cells showed distinct features including a higher activity of cellular adhesion, slower but reproducible progression of angiogenesis on Matrigel, and resistance to apoptosis. Thus, the expression of integrin and activation of extracellular-signal regulated kinase 1/2 (Erk1/2), a downstream effector of the integrin pathway, were examined. Flow cytometry revealed that alpha3beta1 integrin was markedly upregulated in ECV304 cells, while alpha(v)beta1 and alpha5beta1 integrins were slightly downregulated. Consistent with this, the binding activity to collagen type IV and laminin, major extracellular matrices of Matrigel, was increased 1.4- and 1.9-fold in ECV304 cells, respectively. This tight binding may retard the initial stage of sprouting and migration in the angiogenesis of ECV304 cells. It has been further demonstrated that Erk1/2 is constitutively active in ECV304 cells, rendering them resistent to the inhibitory effect of PD98059 on proliferation. However, migration of both HUVEC and ECV304 cells was inhibited to a similar extent by PD98059 in a dose-dependent manner. Up to 50 microM of PD98059, no significant changes in cell binding and tubulogenesis on Matrigel was observed in ECV304 cells. In contrast, the tubulogenesis of HUVEC was severely impaired by PD98059. Elevated Erk1/2 activity in ECV304 cells was suppressed by dominant negative H-Ras, but not by cytochalasin D. These results suggest that the overexpression of alpha3beta1 integrin and the constitutive activation of Erk1/2 play a key role in the alteration of the angiogenic properties of ECV304 cells.

H-Ras is a negative regulator of alpha3beta1 integrin expression in ECV304 endothelial cells

We have examined the role of Ras in integrin expression in ECV304 endothelial cells. Among the integrins examined in stable ECV304 transfectants expressing dominant active H-Ras (DAR-ECV), expression of alpha3beta1 integrin showed a prominent reduction in all the DAR-ECV clones when compared to the parental ECV304 cells. This implies that H-Ras negatively regulates the expression of alpha3beta1 integrin in ECV304 cells. When treated with inhibitors of the Ras downstream pathway (LY294002, PD98059, SB203580), the expression of alpha3beta1 integrin was up-regulated most significantly by LY294002, suggesting that among the downstream pathways of Ras, phosphatidylinositol 3-kinase is a major determinant. With the application of blocking antibody to alpha3beta1 integrin (2 - 2 x 10(4) nM), migration of ECV304 cells was enhanced to maximal (18%) at 20 nM. These results suggest that migration of endothelial cells could be modulated by H-Ras via alteration of the expression levels of alpha3beta1 integrin.