Enjing Jin

Prognostic significance of vascular endothelial growth factor expression in human ovarian carcinoma

The influence of vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) on prognosis and the relationship between VEGF expression and MVD in ovarian carcinoma are not well defined. We studied VEGF expression in parallel with MVD by immunohistochemistry in 94 ovarian tumours (64 malignant, 13 borderline, and 17 benign) and correlated the results with the clinicopathologic prognostic factors of the disease to clarify their significance in this disease. Assessment of VEGF mRNA isoforms by RT-PCR was also performed. Of the malignant, borderline, and benign ovarian tumours respectively, two (3%), four (31%) and 16 (94%) were negative, 31 (48%), seven (54%) and one (6%) had low expressions, and 31 (48%), two (15%) and none (0%) had high expressions of VEGF. There were significant associations between the VEGF expression and disease stage (P = 0.002), histologic grade (P = 0.0004), and patient outcome (P = 0.0002). MVD did not correlate significantly with the clinicopathologic parameters. Likewise, no correlation was found between MVD and VEGF expression. The survival of patients with high VEGF expression was significantly worse than that of patients with low and negative VEGF expression (P = 0.0004). Multivariate analysis revealed that disease stage and VEGF expression were significant and independent prognostic indicators of overall survival time (P = 0.008 and P = 0.006 respectively). These findings suggest that in conjunction with the established clinicopathologic prognostic parameters of ovarian carcinoma, VEGF expression may enhance the predictability of patients at high risk for tumour progression who are potential candidates for further aggressive therapy.

Amplification, up‐regulation and over‐expression of DVL‐1, the human counterpart of the Drosophila disheveled gene, in primary breast cancers

Wnt proteins form a family of highly conserved, secreted signaling molecules that regulate cell‐to‐cell interactions during embryogenesis. Wnt genes and Wnt signaling are also implicated in cancer. It has been shown that Wnt proteins bind to receptors of the frizzled family on the cell surface. Through several cytoplasmic relay components including DVL‐1, the human counterpart of the Drosophila disheveled gene, the signal is transduced to β‐catenin, which then enters the nucleus and forms a complex with T‐cell factor (TCP) to activate transcription of Wnt target genes. We describe here the amplification of DVL‐1 in 13 of 24 primary breast cancers examined, and increased expression of this gene in 11 of those tumors in comparison to corresponding non‐cancerous breast tissues. Immunohistochemical staining demonstrated that DVL‐1 protein was prominent in the cytoplasm of cancer cells, but not in normal epithelial cells of the mammary duct or in myoepithelial cells. These data indicate that amplification and increased expression of the DVL‐1 gene may play some role in human breast carcinogenesis through derangement of the Wnt signaling pathway.

Hypermethylation associated with inactivation of the SOCS-1 gene, a JAK/STAT inhibitor, in human hepatoblastomas

AbstractWe recently demonstrated inactivation in hepatocellular carcinomas (HCCs) of the gene encoding SOCS1/JAB1/SSI-1, a JAK-binding protein that regulates the JAK/STAT signal-transduction pathway. In a follow-up immunochemical investigation of expression of SOCS-1 in hepatoblastomas (HBLs), the protein was markedly reduced in half of the HBL tumors we examined. CpG-rich regions upstream of the SOCS-1 gene were hypermehylated in 7 of the 15 HBL cases. The results suggest that hypermethylation may play an important role in silencing the SOCS-1 gene, not only in adult HCCs, but also in liver tumors arising in childhood.

Changes in coagulation-fibrinolysis marker and neutrophil elastase following the use of tourniquet during total knee arthroplasty and the influence of neutrophil elastase on thromboembolism

Background:  To clarify in detail the mechanism underlying the development and exacerbation of deep venous thrombosis (DVT) and/or pulmonary thromboembolism (PTE), we focused on the following factors: the thrombin‐antithrombin III complex (TAT), D‐dimer and neutrophil elastase (NE). We basically investigated whether NE played an important role in the development of PTE I a mice model.

Immunohistochemical and ultrastructural studies of basal cells, Clara cells and bronchiolar cuboidal cells in normal human airways

Immunohlstochemical studies were made of the distribution of various cytokeratins (CK), Clara cell secretory protein (CC10), surfactant proteln A (SP‐A) and type VII collagen in normal human alrways. Electron microscopic studies were made to Identify hemldesmosomes and anchoring fibrils on the basal surfaces of the epithelial cells. CK19 was detected In all epithelial cells, and CK17 in all basal cells. CK14 was coaxpressed in a few basal cells, and this coexpression was decreased in the distal airways. Two types of basal cells were recognized. One type, found mainly In large airways, was characterized by abundant intermediate filaments and well‐developed hemidesmosomes and anchoring fibrils. The second type contained few intermediate filaments and poorly developed hemidesmosomes and anchoring fibrils. Reactivity for type VII collagen was found along the basement membrane throughout the airways, but not in the alveoli. Clara cells were reactive for CC10 and CK17, but not for CK14 and SP‐A. The bronchiolar cuboidal cells in the respiratory bronchloles were positive only for CK19. Surfactant proteln A was present only in type II alveolar eplthellal cells. Thus, two types of basal cells are present in always, and the bronchiolar cuboidal cells appear distinct from these basal cells, Clara cells and type II alveolar epithelial cells.

Amplification, up-regulation and over-expression of C3G (CRK SH3 domain-binding guanine nucleotide-releasing factor) in non-small cell lung cancers

AbstractThe Ras-CRK-Rap1 cellular signal-transduction system is regulated by guanine nucleotide exchange factors (GEFs). Transcription of C3G on chromosome 9q34 and a key member of the GEF gene family is activated by the CRK-adaptor protein; the C3G product is a CRK SH3 domain-binding guanine nucleotide-releasing factor. We document here the amplification of C3G in five of 18 primary non-small cell lung cancers examined and its increased expression in 18 of 28 tumors in comparison to corresponding non-cancerous lung tissues. Immunohistochemical staining revealed prominent C3G protein in the cytoplasm of cancer cells, associated with faint staining at the nucleolar membrane, but C3G was not detectable in normal bronchial mucoepithelial cells or in broncholoalveolar cells of the bronchial/bronchiolar ducts or alveoli. These data indicate that amplification and increased expression of the C3G gene may play some role in human lung carcinogenesis through derangement of the CRK-Rap1 signaling pathway.

Mosaic-like distribution of endothelial cell antigens in capillaries and juxta-alveolar microvessels in the normal human lung

The distribution patterns of endothelial cell antigens, including thrombomodulin and von Willebrand factor (vWf), were studied in normal lung tissues obtained from distant areas of solitary nodules (seven adenocarcinomas and four hamartomas). By single immunoalkaline phosphatase and dual immunofluorescence stainings, the plasma membranes of alveolar capillary endothelium showed linear distribution of thrombomodulin, but their cytoplasm was rarely reactive for vWf (thrombomodulin‐dominant pattern). Microvessels with a diameter larger than 10 μm located in the connective tissue zones demonstrated band‐like reaction for vWf in their cytoplasm, and their plasma membranes often lacked reactivity for thrombomodulin (vWf‐dominant pattern). The juxta‐alveolar microvessels located along the borders between the alveolar‐ and connective‐tissue zones showed mosaic‐like pattern of distribution for these antigens. The pulmonary venules and peribronchial microvessels measuring up to 40 μm in diameter, demonstrated the expression of thrombomodulin along the plasma membrane, and that of vWf in the cytoplasm. Capillaries of the bronchial circulation were also characterized by mosaic‐like pattern of distribution. Both antigens were often expressed in a single cytoplasmic segment. The heterogeneous distribution pattern of these antigens suggests topographic difference in endothelial cell function to maintain coagulatory and anticoagulatory balance in the normal human lung.

Role of cdk4, p16INK4, and Rb Expression in the Prognosis of Bronchioloalveolar Carcinomas

Background: The p16INK4 protein has been identified as a potent inhibitor of cyclin-dependent kinase (cdk)4 by blocking cdk4-mediated phosphorylation of the tumor suppressor retinoblastoma (Rb) protein, thus allowing Rb-mediated growth suppression. Objectives: Loss of p16INK4 has been associated with a poor cancer prognosis, but its potential significance in bronchioloalveolar carcinomas (BACs) has not been explored. Methods: We examined immunohistochemical expression of p16INK4, cdk4, and Rb proteins in 38 BACs and correlated their expression levels with known clinicopathological features of the disease. Results: All BACs expressed cdk4, while 89 and 82% expressed p16INK4 and Rb proteins, respectively. None of the clinicopathological factors correlated with p16INK4, cdk4, or Rb expression separately. A low p16INK4/cdk4 ratio was significantly associated with a high disease stage (p = 0.04), and the ratio tended to be lower in mucinous than nonmucinous tumors. BACs with a low p16INK4/cdk4 ratio showed significantly higher Rb expression levels (p = 0.02). Univariable survival analyses showed a significantly lower 5-year survival probability in patients with a high stage (p = 0.002) or low p16INK4/cdk4 ratio (p = 0.01). Conclusions: The results suggest a role of the cdk4/p16INK4 pathway in the prognosis of BACs. Further studies are warranted to clarify whether a low p16INK4/cdk4 ratio may identify tumors that are destined to behave unfavorably.

Angiogenesis and phenotypic alteration of alveolar capillary endothelium in areas of neoplastic cell spread in primary lung adenocarcinoma.

Normal alveolar capillary endothelium is quiescent in nature and displays anticoagulant thrombomodulin (TM) on its surface. The cytoplasms of these endothelial cells are ultrastructurally non‐fenestrated type, and they barely express von Willebrand factor (vWf). Alveolar fibrosis is accompanied by a capillary endothelium reactive for vWf, and a loss of TM expression. In primary lung adenocarcinoma, neovascularization occurs in association with alveolar fibrosis. In order to study basic factors related to angiogenesis and phenotypic changes of the capillaries located in tumor‐bearing alveolar walls, we examined 37 primary lung adenocarcinomas with electron microscopy and confocal laser scanning microscopy with antibodies for TM, vWf, vascular endothelial growth factor (VEGF), and its receptors (KDR and Flt‐1), and proliferating markers (Ki‐67/proliferating cell nuclear antigen). Tissues microdissected specifically from alveolar walls were used for reverse transcription–polymerase chain reaction (RT–PCR) to assess expressions of mRNA isoforms of VEGF and its receptors. New capillary branching was found by ultrastructural study in the alveolar walls in 12% of the patients. Nuclei of the capillary endothelial cells were reactive for proliferating cell markers. Endothelial fenestrae were developed in 65% of the patients, TM reactivity was lost in the alveolar capillaries, and their cell cytoplasms obtained a reactivity for vWf through a transitional mosaic‐like distribution pattern of both antigens. Besides cytoplasmic VEGF expression in neoplastic cells, tumor‐bearing alveolar walls showed significant expression of mRNA of VEGF165 and KDR. These findings imply that angiogenesis and phenotypic changes of the alveolar capillaries are closely related to a higher expression of tumor‐associated VEGF165 and of KDR in the alveolar walls in primary lung adenocarcinoma.

Differential expression of protease-activated receptors 1, 2, and 4 on human endothelial cells from different vascular sites.

Objective: Protease-activated receptors (PARs) mediate DNA synthesis in endothelial cells when activated by serine proteases. However, despite the existence of heterogeneity among endothelial cells from each tissue, the responses to PAR-1, PAR-2, and PAR-4 activation are poorly defined and compared between endothelial cells from different sites. The aim of this study was to investigate whether PAR-mediated DNA synthesis differed in various endothelial cell types. Methods: We examined the incorporation of BrdU by human pulmonary artery endothelial cells (HPAECs), human aortic endothelial cells (HAECs), and human umbilical vein endothelial cells (HUVECs). Results: When the endothelial cells were treated with the selective PAR-1-activating peptide, SFLLRN, HAECs showed the highest BrdU incorporation rate (182 ± 28%). In contrast, treatment with the PAR-2-activating peptide, SLIGKV, resulted in the highest BrdU incorporation rate (173 ± 37%) in HPAECs, when pretreated with TNF-α. The PAR-4-activating peptide, GYPGQV, induced DNA synthesis in HPAECs and HAECs, but not in HUVECs. Conclusion: These findings suggest that each PAR preferentially targets an endothelial cell type, and thus plays a distinct role in diverse physiological or pathological conditions.