Utility of pVHL, maspin, IMP3, S100P and Ki67 in the distinction of autoimmune pancreatitis from pancreatic ductal adenocarcinoma.

Morphology plays an important role in the distinction of autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC). However, we aimed to determine the utility of immunohistochemical tumor markers to contribute in the distinction of these entities. In surgical specimens with AIP (n = 20), PDAC (n = 20) and normal pancreas (n = 20), the expression of pVHL, maspin, IMP3, S100P and Ki67 was examined. We evaluated intralobular reactive ducts / acinoductal metaplasia (ILDs) and extralobular ducts (ELDs) in AIP, neoplastic glands in PDAC, and ductal epithelium in the normal pancreas, using a five-tiered scoring system. The Ki67 hot spot index (Ki67-HSPI) was determined manually and using automated digital imaging analysis of virtual double stains of Ki67 and CK8. Besides, sequential dual-immunohistochemical staining of maspin/pVHL, maspin/IMP3 and Ki67/maspin was performed in a subset of the specimens. Strong overexpression of IMP3, maspin, S100P and Ki67 and loss of pVHL was observed in PDAC compared to AIP and normal pancreas. In AIP however, focal and weak aberrant expression was observed with the following proportions in ILDs/ELDs: pVHL in 45 %/85 %, maspin in 30 %/70 %, IMP3 in 55 %/5%, S100P in 10 %/35 % and Ki67-HSPI >20 % in 15 %/70 %. At least two markers were aberrantly expressed in ILDs/ELDs in 45 %/60 %. The aberrant expression was more pronounced in type 2 AIP compared to type 1. In conclusion, our data indicate that pVHL, maspin, IMP3, S100P and Ki67 can be focal and weak aberrantly expressed in AIP. However, when used as a panel, these markers seem to be useful for the differentiation of AIP from PC.

Case report on two diabetic donor eyes with no retinopathy: Clinicopathological and molecular studies.

We were intrigued to analyze donor eyes of two individuals without retinopathy even after 40 years of type 2 diabetes mellitus. Targeted molecular factors associated with angiogenesis and the key antioxidant enzymes in retinal tissue were analyzed. Accordingly PEDF, Adiponectin and Paraoxonase 2 showed augmented mRNA expression in both the retina with no significant change in VEGF expression. Vitreous showed increased PEDF protein in donor 1 and Adiponectin in donor 2 with no change in VEGF protein. This study highlights the profile of specific molecular factors that contribute to the non-development of diabetic retinopathy changes in these individuals.

PEDF increases GLUT4-mediated glucose uptake in rat ischemic myocardium via PI3K/AKT pathway in a PEDFR-dependent manner.

BACKGROUND: Targeted increase in glucose uptake of ischemic myocardium is a potential therapeutic strategy for myocardial ischemia. PEDF presents a profound moderating effect on glucose metabolism of cells, but its role is still controversial. Here, we try to demonstrate the direct effect of PEDF on glucose uptake in ischemic myocyte and to elucidate its underlying mechanism. METHODS AND RESULTS: Lentivirus vectors carrying PEDF gene were delivered into the myocardium to locally overexpress PEDF in a myocardial ischemia/reperfusion rat model. PET imaging showed that PEDF local overexpression increased [18F]-FDG uptake of ischemic myocardium. In vitro, PEDF directly increased the glucose uptake in hypoxic cardiomyocytes. The expression of glucose transporter 4 (GLUT4) on plasma membrane of hypoxic cardiomyocytes was significantly upregulated by PEDF, but its total amount was not changed. The increased glucose uptake and cardioprotective effects induced by PEDF were blocked by the GLUT4 inhibitor indinavir. PEDF-mediated GLUT4 translocation and glucose uptake increase in hypoxic cardiomyocytes were prevented by phosphatidyl-inositol-3 kinase (PI3K) inhibitor or AKT inhibitor. The PEDF-mediated glucose uptake was also diminished when PEDF receptor (PEDFR) was downregulated or potent phospholipase A2 enzymatic activity was inhibited. CONCLUSIONS: PEDF can increase glucose uptake in ischemic myocardium through a PEDFR-dependent mechanism, involving PI3K/AKT signaling and GLUT4 translocation.

Mesenchymal Stromal Cells and Natural Killer Cells: A Complex Story of Love and Hate.

Mesenchymal stromal cells (MSCs), characterized by both multidifferentiation potential and potent immunomodulatory capacity, represent a promising, safe and powerful cell based-therapy for repairing tissue damage and/or treating diseases associated with aberrant immune responses. Natural killer (NK) cells are granular lymphocytes of the innate immune system that function alone or in combination with other immune cells to combat both tumors and virally infected cells. After their infusion, MSCs are guided by host inflammatory elements and can interact with different immune cells, particularly those of the innate immune system. Although some breakthroughs have been achieved in understanding these interactions, much remains to be determined. In this review, we discuss the complex interactions between NK cells and MSCs, particularly the importance of improving the therapeutic value of MSCs.

Forkhead box protein O1 (FoxO1) regulates hepatic serine protease inhibitor B1 (serpinB1) expression in a non-cell-autonomous fashion.

FoxO proteins are major targets of insulin action, and FoxO1 mediates the effects of insulin on hepatic glucose metabolism. We reported previously that serpinB1 is a liver-secreted factor (hepatokine) that promotes adaptive ß-cell proliferation in response to insulin resistance in the liver-specific insulin receptor knockout (LIRKO) mouse. Here we report that FoxO1 plays a critical role in promoting serpinB1 expression in hepatic insulin resistance in a non-cell-autonomous manner. Mice lacking both the insulin receptor and FoxO1 (LIRFKO) exhibit reduced ß-cell mass compared with LIRKO mice because of attenuation of ß-cell proliferation. Although hepatic expression of serpinB1 mRNA and protein levels was increased in LIRKO mice, both the mRNA and protein levels returned to control levels in LIRFKO mice. Furthermore, liver-specific expression of constitutively active FoxO1 in transgenic mice induced an increase in hepatic serpinB1 mRNA and protein levels in refed mice. Conversely, serpinB1 mRNA and protein levels were reduced in mice lacking FoxO proteins in the liver. ChIP studies demonstrated that FoxO1 binds to three distinct sites located ∼9 kb upstream of the serpinb1 gene in primary mouse hepatocytes and that this binding is enhanced in hepatocytes from LIRKO mice. However, adenoviral expression of WT or constitutively active FoxO1 and insulin treatment are sufficient to regulate other FoxO1 target genes (IGFBP-1 and PEPCK) but not serpinB1 expression in mouse primary hepatocytes. These results indicate that liver FoxO1 promotes serpinB1 expression in hepatic insulin resistance and that non-cell-autonomous factors contribute to FoxO1-dependent effects on serpinB1 expression in the liver.

Epigallocatechin gallate inhibits corneal neovascularization in ratalkaline burn model.

To evaluate the effectiveness of epigallocatechin gallate (EGCG) in inhibiting corneal neovascularization in rat alkaline burn model. Corneal neovascularization model was induced by sodium hydroxide alkaline burn injury in SD rats. Rats were randomly divided into two groups and were given intraperitoneal injection with EGCG or PBS per day for up to 14 days respectively. Corneal inflammation and neovascularization area were assessed on days 3, 7, and 14 after cauterization with digital photographs. Vascular endothelial growth factor (VEGF) and pigment epithelium derived factor (PEDF) mRNA levels were measured by reverse transcription-polymerase chain reaction (qRT-PCR). The nuclear transfactor-Κb (NF-κB) subunit P65 protein was assayed by immunohistochemistry. The differences of corneal inflammation scores between two groups were significant. The area of CNV between two groups had no significant difference on day 3 but have significant difference on days 7 and 14.The PDEF mRNA expression in EGCG group was significantly higher and the expression of VEGF mRNA was lower than those in PBS group. The results of immunohistochemistry showed from day 7, expression of NF-κB P65protein was suppressed considerably in EGCG group. This study demonstrates that EGCG inhibits corneal neovascularization in a rat model induced by alkali burn.

In vivo expression of proteases and protease inhibitor, a serpin, by periodontal pathogens at teeth and implants.

Porphyromonas gingivalis and Tannerella forsythia secrete proteases, gingipains and KLIKK-proteases. In addition, T. forsythia produces a serpin (miropin) with broad inhibitory spectrum. The aim of this pilot study was to determine the level of expression of miropin and individual proteases in vivo in periodontal and peri-implant health and disease conditions. Biofilm and gingival crevicular fluid (GCF)/ peri-implant sulcular fluid (PISF) samples were taken from healthy tooth and implant sites (n = 10), gingivitis and mucositis sites (n = 12), and periodontitis and peri-implantitis sites (n = 10). Concentration of interleukin-8 (IL-8), IL-1ß and IL-10 in GCF was determined by enzyme-linked immunosorbent assay. Loads of P. gingivalis and T. forsythia and the presence of proteases and miropin genes were assessed in biofilm by quantitative PCR, whereas gene expression was estimated by quantitative RT-PCR. The presence of P. gingivalis and T. forsythia, as well as the level of IL-8 and IL-1ß, were associated with disease severity in the periodontal and peri-implant tissues. In biofilm samples harboring T. forsythia, genes encoding proteases were found to be present at 72.4% for karilysin and 100% for other KLIKK-protease genes and miropin. At the same time, detectable mRNA expression of individual genes ranged from 20.7% to 58.6% of samples (for forsylisin and miropsin-1, respectively). In comparison with the T. forsythia proteases, miropin and the gingipains were highly expressed. The level of expression of gingipains was associated with those of miropin and certain T. forsythia proteases around teeth but not implants. Cumulatively, KLIKK-proteases and especially miropin, might play a role in pathogenesis of both periodontal and peri-implant diseases.

Secretome analysis of rat osteoblasts during icariin treatment induced osteogenesis.

Osteoporosis is a serious public health problem and icariin (ICA) is the active component of the Epimedium sagittatum, a traditional Chinese medicinal herb. The present study aimed to investigate the effects and underlying mechanisms of ICA as a potential therapy for osteoporosis. Calvaria osteoblasts were isolated from newborn rats and treated with ICA. Cell viability, apoptosis, alkaline phosphatase activity and calcium deposition were analyzed. Bioinformatics analyses were performed to identify differentially expressed proteins (DEPs) in response to ICA treatment. Western blot analysis was performed to validate the expression of DEPs. ICA administration promoted osteoblast viability, alkaline phosphatase activity, calcium deposition and inhibited osteoblast apoptosis. Secretome analysis of ICA­treated cells was performed using two­dimensional gel electrophoresis and matrix­assisted laser desorption/ionization time­of­flight mass spectrometry. A total of 56 DEPs were identified, including serpin family F member 1 (PEDF), protein disulfide isomerase family A, member 3 (PDIA3), nuclear protein, co­activator of histone transcription (NPAT), c­Myc and heat shock protein 70 (HSP70). These proteins were associated with signaling pathways, including Fas and p53. Bioinformatics and western blot analyses confirmed that the expression levels of the six DEPs were upregulated following ICA treatment. These genes may be directly or indirectly involved in ICA­mediated osteogenic differentiation and osteogenesis. It was demonstrated that ICA treatment promoted osteogenesis by modulating the expression of PEDF, PDIA3, NPAT and HSP70 through signaling pathways, including Fas and p53.

Comparative expression of PEDF and VEGF in human epidermal keratinocytes and dermal fibroblasts: from normal skin to psoriasis.

Vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) have been shown to keep angiogenesis activation and inhibition in balance in normal and pathological conditions. In this study, we examined the expression of VEGF and PEDF in keratinocytes and fibroblasts from normal and psoriatic skin to evaluate their potential roles and interactions in the development of psoriasis. The expression of VEGF and PEDF was detected in normal and psoriatic skin ex vivo and in co-cultured keratinocytes and fibroblasts in vitro, and increased in keratinocytes and fibroblasts from psoriatic skin compared with those cells from normal skin. Our results suggest that PEDF act as a multipotent factor in the skin and the imbalance of PEDF and VEGF may be responsible for the transformation from normal skin to psoriasis.

Maspin Enhances the Anticancer Activity of Curcumin in Hormone-refractory Prostate Cancer Cells.

BACKGROUND/AIM: Androgen deprivation therapy remains the principal treatment for patients with advanced prostate cancer, though, most patients will eventually develop hormone-refractory prostate cancer (HRPC). Androgen ablation mediated maspin-induction has been identified in cancer patients. However, the role of maspin on the anticancer activity of curcumin derived from turmeric (Curcuma longa) in HRPC cells has not been elucidated. MATERIALS AND METHODS: The anticancer action of curcumin in hormone-independent prostate cancer cells (DU145, and PC-3) was determined by measures of cell survival rate. The cause of maspin silencing on the anti-tumor abilities of curcumin in PC-3 cells was evaluated by measures of cell survival rate, cell-cycle distribution, and apoptosis signaling analysis. RESULTS: Our present study showed that PC-3 cells (with higher maspin expression) were more sensitive than DU145 cells to curcumin treatment (with lower maspin expression). RNA interference-mediated maspin silencing reduced curcumin sensitivity of PC-3 cells, as evidenced by reduced apoptotic cell death. After exposure to curcumin, maspin-knockdown cells showed lower expression levels of pro-apoptotic proteins, Bad and Bax, as compared with control cells. CONCLUSION: Maspin can enhance the sensitivity of HRPC cells to curcumin treatment.

Tumour size, volume, and marker expression during radiation therapy can predict survival of cervical cancer patients: a multi-institutional retrospective analysis of KROG 16-01.

OBJECTIVE: The aim of this multi-institutional study was to determine the prognostic impact of tumour parameters, such as tumour size (TS), tumour volume (TV), and marker expression, on survival during radiation therapy (RT) for cervical cancer patients. METHODS: A total of 231 patients with histologically confirmed cervical cancer, classified as Federation of Gynecology and Obstetrics (FIGO) Ib2-IVa, were enrolled in this study. Pre- and mid-RT pelvic magnetic resonance imaging (MRI) and squamous cell carcinoma antigen (SCC-ag) analysis were performed twice, during RT and just before brachytherapy. RESULTS: The median follow-up time was 27.8months (range, 2-116months). Multivariate analysis revealed that stage (odds ratio [OR], 2.936 and 95% confidence interval [CI], 1.119-7.707; P=0.029), tumour volume reduction rate (TVRR) (OR, 3.435 and 95% CI, 1.062-11.106; P=0.039), and SCC-ag reduction rate (SCCRR) (OR, 5.104 and 95% CI, 1.769-14.727; P=0.003) were independently associated with overall survival (OS), while pre-RT TS (OR, 2.148 and 95% CI, 1.221-3.810; P=0.009), mid-RT TV (OR, 3.106 and 95% CI, 1.685-5.724; P<0.0001) and SCCRR (OR, 1.954 and 95% CI, 1.133-3.369; P=0.016) were associated with progression-free survival (PFS). Based on the prognostic factor analysis, patients with the highest prognostic risk score of 3 showed poorer overall survival and progression free survival than patients with lower prognostic risk scores. CONCLUSION: We identified that tumour parameters such as TVRR, SCCRR, pre-RT TS, and mid-RT TV areindependent and strong prognostic parameters for patients with cervical cancer receiving RT. This scoring system-based prognostic factor analysis could be used to help develop optimized treatment plans for cervical cancer patients during RT.

Corneal Mesenchymal Stromal Cells Are Directly Antiangiogenic via PEDF and sFLT-1.

Purpose: To evaluate the angiogenic properties of corneal derived mesenchymal stromal cells (Co-MSC). Methods: Co-MSCs were extracted from human cadaver, and wild-type (C57BL/6J) and SERPINF1-/- mice corneas. The MSC secretome was collected in a serum-free medium. Human umbilical vein endothelial cell (HUVEC) tube formation and fibrin gel bead assay (FIBA) sprout formation were used to assess the angiogenic properties of Co-MSC secretome. Complete corneal epithelial debridement was used to induce corneal neovascularization in wild-type mice. Co-MSCs embedded in fibrin gel was applied over the debrided cornea to evaluate the angiogenic effects of Co-MSCs in vivo. Immunoprecipitation was used to remove soluble fms-like tyrosine kinase-1 (sFLT-1) and pigment epithelium-derived factor (PEDF, SERPINF1 gene) from the Co-MSC secretome. Results: Co-MSC secretome significantly inhibited HUVECs tube and sprout formation. Co-MSCs from different donors consistently contained high levels of antiangiogenic factors including sFLT-1 and PEDF; and low levels of the angiogenic factor VEGF-A. In vivo, application of Co-MSCs to mouse corneas after injury prevented the development of corneal neovascularization. Removing PEDF or sFLT-1 from the secretome significantly diminished the antiangiogenic effects of Co-MSCs. Co-MSCs isolated from SERPINF1-/- mice had significantly reduced antiangiogenic effects compared to SERPINF1+/+ (wild-type) Co-MSCs. Conclusions: These results illustrate the direct antiangiogenic properties of Co-MSCs, the importance of sFLT-1 and PEDF, and their potential clinical application for preventing pathologic corneal neovascularization.

Nuclear maspin expression: A biomarker for budding assessment in colorectal cancer specimens.

AIM: To evaluate the maspin expression in colorectal carcinomas (CRC) and its possible role in quantification of the tumor budding. METHODS: The tumor budding was prospectively quantified in 49 consecutive cases of patients that underwent surgical resection for CRC. The cases were divided in two groups: group A (n=23) - low budding (<5 tumor buds per high microscopic field) and group B (n=26) - high budding CRCs (≥5 buds). Maspin expression was evaluated in the tumor core and the buds from the hot spot area in 44 of the microsatellite stable adenocarcinomas. Its expression was quantified as negative, cytoplasmic only, nuclear only or mixed expression (cytoplasm and nucleus). RESULTS: Compared with group A, a higher pT (p <0.0001) and pN stage (p=0.0001) and infiltrating aspect at macroscopic evaluation (p=0.0081) was identified in group B. No correlation between the maspin expression in the tumore core and the budding grade was noted (p=0.14). Compared with the tumor core, the cytoplasm to nuclear translocation of maspin was more frequently observed in cases from group B than A (n=0.0063). CONCLUSION: For the colorectal carcinomas, the infiltrative aspect at macroscopic evaluation and nuclear maspin in the buds might be used as indicators of risk for lymph node metastases. Maspin nuclear expression in the buds may be helpful for a proper budding assessment and may serve as a negative prognostic factor.

Synthesis, localization and possible function of serine (or cysteine) peptidase inhibitor, clade B, member 6a (Serpinb6a) in mouse submandibular gland.

The granular convoluted tubule (GCT) in the duct system of the submandibular gland (SMG) develops preferentially in male mice and produces a number of bioactive peptides including proteases such as renin and kallikrein. We examine the synthesis and localization of the serine (or cysteine) peptidase inhibitor, clade B, member 6a (Serpinb6a), the mouse ortholog of the human intracellular serine protease inhibitor SERPINB6, in the mouse SMG by using reverse transcription plus the polymerase chain reaction, in situ hybridization, immunoblotting and immunohistochemistry. Serpinb6a mRNA expression was more abundant in the male than in the female SMG and in the GCT than in other duct portions or acini. Within GCT cells, immunoreactivity for Serpinb6a was localized in the nucleus and cytosol but was absent in the secretory granules. The binding target of Serpinb6a in the SMG was investigated by using a mass spectrometric analysis of immunoprecipitation products and kallikrein-1-related peptidase b26 (Klk1b26), a serine protease, was identified. These results raise the possibility that Serpinb6a functions in the protection of GCT cells from intracellular kallikreins that may leak from secretory granules.

Transgenic expression of a canonical Wnt inhibitor, kallistatin, is associated with decreased circulating CD19+ B lymphocytes in the peripheral blood.

Members of the family of serine proteinase inhibitors, such as kallistatin, have been shown to inhibit canonical Wnt-TCF/LEF-ß-catenin signaling via their interactions with the Wnt co-receptor LRP6. Yet the effects of transgenic overexpression of anti-Wnt serpins on hematopoiesis and lymphopoiesis are not well known. We studied the effects of human kallistatin (SERPINA4) on Wnt reporter activity in various cell types throughout the hematopoietic system and associated impacts on circulating white blood cell profiles. Transgenic overexpression of kallistatin suppressed Wnt-TCF/LEF-ß-catenin signaling in bone marrow, as demonstrated using a Wnt reporter mouse. Further, kallistatin overexpression and treatment were associated with reduced Wnt-TCF/LEF-ß-catenin activity in CD34+ c-kit+ bone marrow cells and CD19+ B lymphocytes, with reduced levels of these populations in bone marrow and peripheral circulation, respectively. The presence of CD3+CD4+, CD3+CD8+, and CD3- NK1.1+ T lymphocytes were not significantly affected. Our data suggest that overexpression of kallistatin interferes with lymphopoiesis, ultimately impacting the level of circulating CD19+ B lymphocytes.

The pigment epithelium-derived factor (PEDF): an important potential therapeutic agent for infantile hemangioma.

In previous studies, the expression and the role of proangiogenic factors in infantile hemangiomas have been well studied. However, the role of angiogenic inhibitors has been revealed rarely. The expression of PEDF, as the strongest and safe endogenous inhibitor, is still unrecognized until the current study. In order to investigate the expression and significance of the pigment epithelium-derived factor (PEDF) in the proliferating and regressing phases of infantile hemangiomas, the expression of PEDF, VEGF, Ki-67, and CD34 protein in hemangioma tissues was examined with immunohistochemical polymer HRP method in 42 cases during the proliferative phase, 40 cases during the regressing phase, and 11 cases of non-involuting congenital hemangiomas (NICHs). Meanwhile, the mRNA expression of these factors was detected with quantitative realtime RT-PCR. We found the protein and mRNA expression of PEDF in regressing phase was significantly higher than those in proliferative phase and NICHs (P < 0.001), while the protein and mRNA expression of VEGF were much lower (P < 0.001). The microvessel density (MVD), Ki-67 changes, and the expression of PEDF and VEGF were found significantly correlated. These results indicated that the reduction of VEGF and increase in PEDF are causative to the evolution of infantile hemangioma. PEDF may play a key role in the spontaneous regression of infantile hemangioma and may become an important potential therapeutic agent for infantile hemangioma.

Double immunostaining for maspin and p53 on cell blocks increases the diagnostic value of biliary brushing cytology.

Our objective is to elucidate the usefulness of maspin/p53 double immunostaining on biliary brushing cytology specimens. We first examined the expression of maspin in the biliary epithelium with variable degrees of dysplasia using surgically resected specimens (n = 56). Maspin appeared to be overexpressed in a stepwise manner from benign to malignant cholangiocytes: the reactive epithelium (20%), biliary intraepithelial neoplasia (~50%), and invasive cholangiocarcinomas (>90%). Next, an automated sequential double immunostaining protocol for maspin and p53 was applied to paraffin-embedded cell blocks of the biliary brushing cytology specimens obtained from 58 consecutive patients. Cell block preparation was successful in 44 cases (76%), which were morphologically diagnosed as adenocarcinoma (n = 16), atypical cells not diagnostic for malignancy (n = 10), and benign (n = 18). Double positive cells were observed in 14/16 (88%) morphologically malignant, 6/10 (60%) borderline, and 0/18 benign cases. All 20 positive cases were proven to have pancreatobiliary malignancies by subsequent imaging or pathological analyses. A similar staining protocol for S100P and p53 was also applied to the same cohort; however, the positive frequency was slightly lower than those of maspin and p53 (36% vs. 45%). In conclusion, Maspin/p53 double immunostaining on cell blocks contributes to the detection of malignant cells in biliary brushing cytology specimens.

Squamous cell carcinoma antigen (SCCA) is up-regulated during Barrett's carcinogenesis and predicts esophageal adenocarcinoma resistance to neoadjuvant chemotherapy.

Squamous Cell Carcinoma Antigen (SCCA) is consistently overexpressed in many different solid tumors, and has been associated with both tumor aggressiveness and chemoresistance. No data, however, is currently available on SCCA expression during esophageal Barrett's carcinogenesis, nor on SCCA expression's role on esophageal adenocarcinoma chemoresistance. The SCCA immunohistochemical expression was assessed in a series of 100 biopsy samples covering the whole histological spectrum of Barrett's oncogenesis. Squamous native mucosa was characterized by a moderate to strong cytoplasmic and nuclear SCCA expression in suprabasal, medium, and superficial layers. On the other hand, almost half of the considered lesions did not express SCCA; the other half featured weak to moderate SCCA expression. The relationship between SCCA protein expression and tumor response to neoadjuvant chemotherapy was assessed in 90 esophageal adenocarcinoma specimens (40 biopsy and 50 surgery specimens), stratified according to Mandard tumor regression grade. As observed in other settings, the presence of SCCA expression clustered in the group of tumors characterized by a lower responsiveness to neoadjuvant treatments. The present results suggest an involvement of SCCA in a subset of Barrett-related tumors, and prompt to consider the SCCA-protein expression as response-predictive marker of neoadjuvant therapy in esophageal adenocarcinomas.

Opposing Effects of Oxygen Regulation on Kallistatin Expression: Kallistatin as a Novel Mediator of Oxygen-Induced HIF-1-eNOS-NO Pathway.

Oxidative stress has both detrimental and beneficial effects. Kallistatin, a key component of circulation, protects against vascular and organ injury. Serum kallistatin levels are reduced in patients and animal models with hypertension, diabetes, obesity, and cancer. Reduction of kallistatin levels is inversely associated with elevated thiobarbituric acid-reactive substance. Kallistatin therapy attenuates oxidative stress and increases endothelial nitric oxide synthase (eNOS) and NO levels in animal models. However, kallistatin administration increases reactive oxygen species formation in immune cells and bacterial killing activity in septic mice. High oxygen inhibits kallistatin expression via activating the JNK-FOXO1 pathway in endothelial cells. Conversely, mild oxygen/hyperoxia stimulates kallistatin, eNOS, and hypoxia-inducible factor-1 (HIF-1) expression in endothelial cells and in the kidney of normal mice. Likewise, kallistatin stimulates eNOS and HIF-1, and kallistatin antisense RNA abolishes oxygen-induced eNOS and HIF-1 expression, indicating a role of kallistatin in mediating mild oxygen's stimulation on antioxidant genes. Protein kinase C (PKC) activation mediates HIF-1-induced eNOS synthesis in response to hyperoxia/exercise; thus, mild oxygen through PKC activation stimulates kallistatin-mediated HIF-1 and eNOS synthesis. In summary, oxidative stress induces down- or upregulation of kallistatin expression, depending on oxygen concentration, and kallistatin plays a novel role in mediating oxygen/exercise-induced HIF-1-eNOS-NO pathway.