CXCL12α/SDF-1 from perisynaptic Schwann cells promotes regeneration of injured motor axon terminals

The neuromuscular junction has retained through evolution the capacity to regenerate after damage, but little is known on the inter-cellular signals involved in its functional recovery from trauma, autoimmune attacks, or neurotoxins. We report here that CXCL12α, also abbreviated as stromal-derived factor-1 (SDF-1), is produced specifically by perisynaptic Schwann cells following motor axon terminal degeneration induced by α-latrotoxin. CXCL12α acts via binding to the neuronal CXCR4 receptor. A CXCL12α-neutralizing antibody or a specific CXCR4 inhibitor strongly delays recovery from motor neuron degeneration in vivo Recombinant CXCL12α in vivo accelerates neurotransmission rescue upon damage and very effectively stimulates the axon growth of spinal cord motor neurons in vitro These findings indicate that the CXCL12α-CXCR4 axis plays an important role in the regeneration of the neuromuscular junction after motor axon injury. The present results have important implications in the effort to find therapeutics and protocols to improve recovery of function after different forms of motor axon terminal damage.

Vascular Endothelial Growth Factor (Vegf) and Other Common Tissue Prognostic Indicators in Breast Cancer: A Case-Control Study

VEGF is a specific mitogen and survival factor for endothelial cells and a key promoter of angiogenesis in physiological and pathological conditions. Nevertheless, VEGF tissue evaluation in cancer patients as a prognostic factor compared to the conventional histological and biological parameters is still controversial. In this case-control study, tissue VEGF was retrospectively determined by immunohistochemistry and related to T, N, ER, PgR, c-erbB-2, p53, MIB-1 and cyclin D1 in 129 breast cancer patients. Seventy-four of these patients had developed distant metastases postoperatively. The remaining 55 patients had remained disease-free >10 years after surgery. In 17 (13%) of the 129 patients (six with distant metastases and eleven disease-free) tissue and plasma VEGF were concomitantly evaluated. In univariate analysis no significant differences in VEGF and tumor size were found between metastatic and disease-free patients, whereas there were significant differences in N, ER, PgR, c-erbB-2, p53, MIB-1 and cyclin D1 (p ranging from 0.001 to 0.0001). In multivariate analysis VEGF showed less significance than N, ER, c-erbB-2, MIB-1 and cyclin D1 (p=0.012, p=0.007, p=0.005, p=0.005, p=0.002 and p=0.001, respectively). VEGF was a significant unfavorable prognostic indicator only in the N+ subset (p=0.015), while ER (p=0.05 and p=0.021) and MIB-1 (p=0.031 and p=0.022) were significant in both the N+ and N– subgroups. In multivariate analysis in the 74 metastatic cases VEGF did not show any significance in relation to disease-free interval and overall survival from the time of mastectomy and from the time of relapse, whereas N and PgR did (p ranging from 0.018 to 0.001). In conclusion, tissue VEGF does not seem a suitable candidate to replace conventional histological and other common biological prognostic factors in breast cancer.

Role of circulating endothelial progenitor cells in the reparative mechanisms of stable ischemic myocardium

BACKGROUND

Mobilization of endothelial progenitor cells (EPCs) into circulation from bone marrow in patients with acute myocardial infarction has strong scientific evidence; less is known about EPC mobilization in patients with stable coronary artery disease (CAD). The aim of this study was to investigate the association of stable ischemic heart disease with EPC levels in tissue and blood.

METHODS

Fifty-five consecutive patients admitted to a single treatment center for valve or coronary artery bypass grafting (CABG) surgeries were included in the study. Blood samples were collected in the morning before surgery and analyzed by flow-cytometry to determine peripheral EPC levels (EPC/ml). Tissue EPC (CD34+VEGFR2+) levels were assessed on a right atrial appendage segment.

RESULTS

Mean age was 76±5years, 48% were men, and 53% had CAD The number of CD34+ VEGFR2+ cells in the tissue of patients with CAD was significantly higher (p<0.005) and circulating EPC showed a tendency to be reduced by approximately 20% in peripheral blood of patients with CAD when compared to those without CAD.

CONCLUSION

Patients with stable CAD had higher EPC density values (EPC/mm2) and were more likely to have lower EPC blood levels when compare with normal controls.

Loss of c-KIT expression in thyroid cancer cells

Papillary thyroid carcinoma is the most frequent histologic type of thyroid tumor. Few studies investigated the role of c-KIT expression in thyroid tumors, suggesting a role for this receptor and its ligand in differentiation and growth control of thyroid epithelium and a receptor loss following malignant transformation. We investigated and correlated c-KIT expression levels and two known markers of thyrocytes differentiation, PAX8 and TTF-1, in malignant and benign cytological thyroid samples. Moreover, we performed functional studies on human papillary thyroid carcinoma cell line to associated c-KIT expression to thyrocytes differentiation and tumor proliferation. c-KIT and PAX8 expression resulted higher in benign samples compared to the malignant ones, and the expression levels of these two genes were significantly correlated to each other. We also observed that c-KIT overexpression led to an increase of PAX8 expression level together with a decrease of proliferation. Furthermore, c-KIT overexpressing cells showed a regression of typical morphological features of malignancy. Taken together these results suggest that c-KIT could be involved in the differentiation of thyroid cells and in tumor progression.

Micro-RNA-21 (biomarker) and global longitudinal strain (functional marker) in detection of myocardial fibrotic burden in severe aortic valve stenosis: a pilot study

Aims

Myocardial fibrosis (MF) is a deleterious consequence of aortic valve stenosis (AVS). Global longitudinal strain (GLS) is a novel left ventricular (LV) functional parameter potentially useful to non-invasively estimate MF. MicroRNAs (miRNAs) are non-coding small ribonucleic acids (RNA) modulating genes function, mainly through RNA degradation. miRNA-21 is a biomarker associated with MF in pressure overload. The aim of the present study was to find an integrated algorithm for detection of MF using a combined approach with both bio- and functional markers.

Methods

Thirty-six patients (75.2 ± 8 y.o.; 63 % Female) with severe AVS and preserved LV ejection fraction (EF), candidate to surgical aortic valve replacement (sAVR) were enrolled. Clinical, bio-humoral evaluation (including plasmatic miRNA-21 collected using specific tubes, PAXgene, for stabilization of peripheral RNA) and a complete echocardiographic study, including GLS and septal strain, were performed before sAVR. Twenty-eight of those patients underwent sAVR and, in 23 of them, an inter-ventricular septum biopsy was performed. Tissues were fixed in formalin and embedded in paraffin. Sections were stained with Hematoxylin and Eosin for histological evaluation and with histochemical Masson trichrome for collagen fibers. The different components were calculated and expressed as micrometers². To evaluate tissue miRNA components, sections 2-μm thick were cut using a microtome blade for each slide. Regression analysis was performed to test association between dependent variable and various predictors included in the model.

Results

Despite a preserved EF (66 ± 11 %), patients presented altered myocardial deformation parameters (GLS −14,02 ± 3.8 %; septal longitudinal strain, SSL −9.63 ± 2.9 %; septal longitudinal strain rate, SL-Sr −0.58 ± 0.17 1/s; Septal Longitudinal early-diastolic strain rate, SL-SrE 0.62 ± 0.32 1/s). The extent of MF showed an inverse association with both GLS and septal longitudinal deformation indices (GLS: R² = 0.30; p = 0.02; SSL: R² = 0.36; p = 0.01; SL-Sr: R² = 0.39; p < 0.001; SL-SrE: R² = 0.35; p = 0.001). miRNA-21 was mainly expressed in fibrous tissue (p < 0.0001). A significant association between MF and plasmatic miRNA-21, alone and weighted for measures of structural (LVMi R² = 0.50; p = 0.0005) and functional (SSL R² = 0.35; p = 0.006) remodeling, was found.

Conclusions

In AVS, MF is associated with alterations of regional and global strain. Plasmatic miRNA-21 is directly related to MF and associated with LV structural and functional impairment.

Abstract P1-03-07: The "panta rhei" of breast cancer: Gene expression timeline analysis during progression of microinvasive breast cancer microenvironment

Background. Tumors develop by progression through a series of stages. It is now widely accepted that cancer is attributed to the accumulation of genetic alterations in cells. Every cells of the tumor microenvironment is constantly changing in the flow of the cancer progression. A number of genes have been identified as having functions in various stages of progression in promoting cancer progression in experimental models. However, the association between gene expression alterations and resulting phenotypic alterations with respect to the aggressiveness and migration potential of cancer cells is not fully understood. Therefore, elucidation of genotype–phenotype correlation will be required to further understand the complex process of progression and invasion. All tumors require at least some stroma to meet their needs of nutrition, waste removal, and structure. It has become clear in recent years that stroma is essential for tumor maintenance and growth and has potential as a therapeutic target. Here, we aimed to give a chronological order of gene expression changes given in the dynamical framework of microinvasive breast cancer microenvironment.

Materials and Methods. RNA-seq (Ion Proton technology) was performed on three microinvasive breast cancers, applying new modifications to the usual protocol. For each of them we microdissected 7 different portions of the tumor (around 200 cells), 4 related to the breast epithelium and 3 to the stroma. The regions were selected on the basis of their grade of progression. Breast epithelium was chronologically subdivided in normal breast epithelium (NBE), carcinoma in situ (CIS), emerging invasive fingers (EIF) and invasive breast cancer (IBC). For each of the breast epithelium subdivisions we collected the adjacent stroma (S) except for the in situ portion: S-NBE, S-EIF and S-IBC.

Results: Whole transcriptome analysis performed on each microdissected regions reveals a series of gene expression changes occurring during cancer progression in the breast epithelium along with the adjacent stroma. The dendogram analysis, based on the whole gene expression data of each patient revealed a perfect group organization of the various microdissected portions of stroma and mammary epithelium. Within the dendogram, the organization of Normal, In Situ, EIF and Invasive tissue respected perfectly the biological assumptions.

Conclusions: More thorough analyses are needed to give a clear view of the flow of molecular events starting from the normal breast epithelium to the microinvasive stage, as well as to give a better understanding of the stroma-epithelium molecular means of communication. The analysis of all the molecular changes occuring in the breast epithelium and in the stroma of microinvasive cancer could lead to the development of new therapeutic targets.

Citation Format: Lessi F, Scatena C, Aretini P, Menicagli M, Franceschi S, Ortenzi V, La Ferla M, De Gregorio V, Bevilacqua G, Naccarato GA, Mazzanti CM. The "panta rhei" of breast cancer: Gene expression timeline analysis during progression of microinvasive breast cancer microenvironment. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-03-07.

VHL and HIF-1α: gene variations and prognosis in early-stage clear cell renal cell carcinoma

Von Hipple-Lindau gene (VHL) inactivation represents the most frequent abnormality in clear cell renal cell carcinoma (ccRCC). Hypoxia-inducible factor-1α (HIF-1α) expression is regulated by O2 level. In normal O2 conditions, VHL binds HIF-1α and allows HIF-1α proteasomal degradation. A single-nucleotide polymorphism (SNP) has been found located in the oxygen-dependent degradation domain at codon 582 (C1772T, rs11549465, Pro582Ser). In hypoxia, VHL/HIF-1α interaction is abolished and HIF-1α activates target genes in the nucleus. This study analyzes the impact of genetic alterations and protein expression of VHL and the C1772T SNP of HIF-1α gene (HIF-1α) on prognosis in early-stage ccRCC (pT1a, pT1b, and pT2). Mutational analysis of the entire VHL sequence and the genotyping of HIF-1α C1772T SNP were performed together with VHL promoter methylation analysis and loss of heterozygosis (LOH) analysis at (3p25) locus. Data obtained were correlated with VHL and HIF-1α protein expression and with tumor-specific survival (TSS). VHL mutations, methylation status, and LOH were detected in 51, 11, and 12% of cases, respectively. Our results support the association between biallelic alterations and/or VHL silencing with a worse TSS. Moreover, we found a significant association between the HIF-1α C1772C genotype and a worse TSS. The same association was found when testing the presence of HIF-1α protein in the nucleus. Our results highlight the role of VHL/HIF-1α pathway in RCC and support the molecular heterogeneity of early-stage ccRCC. More important, we show the involvement of HIF-1α C1772T SNP in ccRCC progression.

Granulocyte-macrophage colony-stimulating factor as an autocrine survival-growth factor in human gliomas

We studied the expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) and its receptors (GM-CSF.R) in 20 human brain gliomas with different tumor gradings and demonstrated constitutive high levels of both mRNA gene expression and protein production exclusively in the highest-grade tumors (WHO, III-IV grade). Five astrocytic cell lines were isolated in vitro from glioma cells, which had selectively adhered to plates pre-coated with rhGM-CSF. These cells were tumorigenic when xenografted to athymic mice, and produced GM-CSF constitutively in culture. Two lines, particularly lines AS1 and PG1, each from a patient with glioblastoma multiforme, constitutively over-expressed both GM-CSF and GM-CSF.R genes and secreted into their culture media biologically active GM-CSF. Different clones of the AS1 line, isolated after subsequent passages in vitro and then transplanted to athymic mice, demonstrated higher tumorigenic capacity with increasing passages in vivo. Cell proliferation was stimulated by rhGM-CSF in late-stage malignant clones, whereas apoptosis occurred at high frequency in the presence of blocking anti-GM-CSF antibodies. In contrast, rhGM-CSF did not induce any apparent effect in early-stage clones expressing neither GM-CSF nor GM-CSF.R. The addition of rhGM-CSF or rhIL-1β, to cultures induced the overproduction of both GM-CSF and its receptors and increased gene activation for several functional proteins (e.g. NGF, VEGF, VEGF.R1, G-CSF, MHC-II), indicating that these cells may undergo dynamic changes in response to environmental stimuli. These findings thus revealed: (1) that the co-expression of both autocrine GM-CSF and GM-CSF.R correlates with the advanced tumor stage; (2) that an important contribution of GM-CSF in malignant glioma cells is the prevention of apoptosis. These results imply that GM-CSF has an effective role in the evolution and pathogenesis of gliomas.

KLF4 is a novel candidate tumor suppressor gene in pancreatic ductal carcinoma

Ductal pancreatic carcinoma (DPC) is a deadly disease with an incidence of 9 cases in 100,000 people per year and a mortality rate close to 100%. Allelic losses in the long arm of chromosome 9 are commonly encountered in many human malignancies but no data are yet available about DPC. We screened 40 laser-microdissected DPC samples and 6 pre-invasive lesions for 9 microsatellite mapping markers of region 9q21.3 through 9q34.2. A small overlapping region of deletion, spanning 8 million base pairs, was identified between D9S127 and D9S105. Two genes, RSG3 and KLF4, mapped to 9q31.1 through 9q32, were further investigated. A highly significant association was found between KLF4 gene expression levels and genomic status. Similarly, absence of immunohistochemical expression of KLF4 protein was found in 86.8% cases of DPC (33/38). Overexpression of KLF4 in a human pancreatic carcinoma cell line induced a significant decrease in the proliferation associated with up-regulation of p21 and the down-regulation of cyclin D1. In conclusion, we identified a novel oncosuppressor region located at the 9q 31.1-3 locus that is lost in DPC at high frequency. Loss of KLF4 expression is closely related to the genomic loss, and its restoration inhibits cancer cell proliferation, suggesting a key suppressor role in pancreatic tumorigenesis.

Tumor infiltrating lymphocytes but not serum pituitary antibodies are associated with poor clinical outcome after surgery in patients with pituitary adenoma

CONTEXT

Serum pituitary antibodies (Pit Abs) and tumor-infiltrating lymphocytes (TILs) have been described in pituitary adenomas, but their clinical significance remains unknown.

OBJECTIVE

The objective of the study was to assess Pit Abs and TILs prevalence in pituitary adenomas and their influence on clinical outcome.

DESIGN

This was a prevalence case-control study.

PATIENTS AND SETTING

Two hundred ninety-one pituitary adenoma cases (110 non-secreting, 30 ACTH-69 GH-71 prolactin- and 13 TSH-secreting adenoma; 177 operated and 114 untreated), 409 healthy controls, and 14 autoimmune hypophysitis were enrolled in a tertiary referral center.

INTERVENTION

Pit Abs were measured using immunofluorescence in all cases and controls (n = 714). The presence of TILs was evaluated using CD45 staining in a subset of adenomas surgically treated (n = 72).

MAIN OUTCOME MEASURE

Clinical response of pituitary adenoma after surgery was evaluated.

RESULTS

Pit Abs prevalence was higher in adenomas (5.1%) than healthy subjects (0.7%, P < 0.0001) and lower than in autoimmune hypophysitis patients (57%, P < 0.0001). Similarly, TILs prevalence was higher in adenomas than normal pituitary (P = 0.01) and lower than in autoimmune hypophysitis (P < 0.0001). No correlation between Pit Abs and TILs was found (P = 0.78). A poor clinical outcome was more common in adenoma patients with TILs (11 of 18, 61%) than in those without (17 of 54, 31%, P = 0.026). Multivariate regression analysis identified the presence of TILs as independent prognostic factor for persistence/recurrence of pituitary adenoma.

CONCLUSIONS

TILs and Pit Abs are present in a significant number of pituitary adenoma patients. Cell-mediated immunity appears to be predictive of a less favorable clinical outcome.

Prognostic role of histological necrosis for nonmetastatic clear cell renal cell carcinoma: correlation with pathological features and molecular markers

PURPOSE

We defined the prognostic role of tumor necrosis and its extent in nonmetastatic clear cell renal cell carcinoma. Also, we further investigated its pathogenesis by correlating this tumor feature with other pathological characteristics and molecular markers related to the von Hippel Lindau-hypoxia inducible factor pathway and to tumor proliferation.

MATERIALS AND METHODS

A total of 213 patients with nonmetastatic clear cell renal cell carcinoma were evaluated. Mean followup was 66 months. The presence and extent of histological necrosis were correlated with clinicopathological factors, Ki-67 antigen expression calculated by the MIB-1 (Ki-67 antibody) index, pVHL, HIF-1alpha, the tumor infiltrating lymphocyte subset and cancer specific survival.

RESULTS

Histological necrosis was present in 63.8% of clear cell renal cell carcinoma cases. Necrosis was significantly associated with grade and the degree of tumor infiltrating lymphocytes, while its extent correlated significantly with grade, the degree of tumor infiltrating lymphocytes and stage. Tumor necrosis was a significant prognostic factor, which was confirmed even when limiting analysis to patients with intracapsular renal cell carcinoma. On multivariate analysis histological necrosis was not an independent predictor of cancer specific survival. The extent of tumor necrosis was not a significant prognostic factor. The presence and extent of histological necrosis was not associated with high Ki-67 expression and it did not correlate with pVHL expression or with nuclear and cytoplasmic HIF-1alpha expression.

CONCLUSIONS

Based on our results we cannot support histological necrosis and its extent as prognostic factors for clear cell renal cell carcinoma. Efforts should be made to develop nomograms that use routinely available and objective predictor variables. The precise mechanism that causes tumor necrosis remains unknown but the host immune response might significantly contribute to its development.

Missense mutations in the TGM2 gene encoding transglutaminase 2 are found in patients with early-onset type 2 diabetes. Mutation in brief no. 982. Online

Transglutaminase 2 (TG2 or TGM2) is a multi-functional enzyme which catalyzes transamidation reactions or acts as a G-protein in intracellular signalling. Tgm2-/- Mice lacking TG2 activity are glucose intolerant and show impairment of insulin secretion, suggesting an important physiological role for TG2 in the pancreatic beta cell. We have previously described a TGM2 heterozygous missense mutation ((c.998A>G, p.N333S) in a 14 year-old patient with insulin-treated diabetes and in his diabetic father. The aim of this study was to further investigate the role of TG2 in early-onset type 2 diabetes. We analysed the TGM2 gene in 205 patients with clinically defined Maturity Onset Diabetes of the Young (MODY) or early-onset type 2 diabetes. We found two novel heterozygous mutations (c.989T>G, p.M330R; c.992T>A, p.I331N), which were not detected in 300 normoglycemic controls. All mutations were in residues which are located close to the catalytic site and impaired transamidating activity in vitro. Gene expression of TGM family genes and localization of TG2 in normal human pancreas indicated that TG2 is the only transglutaminase significantly expressed in human pancreatic islet cells. We conclude that reduced TG2 activity can contribute to disorders of glucose metabolism possibly via an impairment of insulin secretion.

P53 gene status in patients with advanced serous epithelial ovarian cancer in relation to response to paclitaxel- plus platinum-based chemotherapy and long-term clinical outcome

BACKGROUND

The aim of this retrospective study was to assess whether p53 gene status has any predictive or prognostic relevance in patients with advanced, poorly-differentiated serous epithelial ovarian cancer treated with paclitaxel- plus platinum-based chemotherapy.

MATERIALS AND METHODS

The study was conducted on 46 patients who underwent surgery followed by paclitaxel- plus carboplatin-based chemotherapy. The tumor tissue samples were analyzed for p53 gene mutations. The median follow-up of survivors was 50.3 months.

RESULTS

Twenty-three patients (50%) showed p53 mutations at exons 5 to 9. Sixteen (34.8%) patients had a polymorphism at codon 72 in exon 4 (SNP codon 72): 10 were Pro/Pro homozygous and 6 Pro/Arg heterozygous. Four polymorphic patients had a second mutation at exons 5 to 9. An inverse correlation was evidenced between the SNP codon 72 and mutations at exons 5 to 9, with the latter more frequently found in wild-type (Arg/Arg) codon 72 (19/30 versus 4/16, 63.3% versus 25.0%; p=0.03) cases. A clear trend for a higher response rate and longer progression-free and overall survival was observed in wild-type p53 and Pro/Pro polymorphic patients as compared to patients with mutant p53.

CONCLUSION

The addition of paclitaxel to carboplatin does not appear to overcome the negative predictive and prognostic significance of p53 gene mutations in serous ovarian cancer. Nevertheless, the comprehensive analysis of p53 genotype, including the SNP codon 72, warrants further investigation in order to envisage individual responsiveness to cancer therapy.

Inflammatory cells contribute to the generation of an angiogenic phenotype in pancreatic ductal adenocarcinoma

BACKGROUND

Inflammatory cells contribute to the growth and spread of human malignancies by producing molecules that enhance tumour invasiveness.

AIMS

To characterise the inflammatory infiltrate in pancreatic ductal adenocarcinoma and to analyse its contribution to angiogenesis and its prognostic relevance.

METHODS

Immunohistochemistry was used to identify inflammatory cells and evaluate the expression of proangiogenic and prolymphangiogenic molecules (vascular endothelial growth factor A (VEGF-A), VEGF-C, and basic fibroblast growth factor (bFGF)) by inflammatory and cancer cells in 137 pancreatic cancers. Intratumorous microvessel density (IMD) was assessed using CD34 as an endothelial cell marker.

RESULTS

There were significantly more mast cells and macrophages in pancreatic cancers than in normal pancreas and the number of mast cells directly correlated with the presence of lymph node metastases. However, there was no relation between numbers of infiltrating inflammatory cells and the presence of chronic pancreatitis (CP)-like changes in the parenchyma surrounding the tumour. Double immunostaining revealed that both pancreatic mast cells and macrophages express VEGF-A, VEGF-C, and bFGF. These factors were also expressed in the tumour cells in many cases. The numbers of VEGF-A expressing tumour cells and bFGF expressing tumour and inflammatory cells significantly correlated with IMD. Moreover, tumours with higher IMD had higher numbers of infiltrating mast cells and macrophages.

CONCLUSIONS

Mononuclear inflammatory cells of the non-specific immune response are recruited to pancreatic cancer tissues independent of the presence of CP-like changes, may influence the metastatic capacity of the cancer cells, and may contribute to the development of tumours with high angiogenic activity.

Angiogenesis in human normal and pathologic adrenal cortex

The angiogenic phenotype of 13 normal adrenal glands (N), 13 aldosterone-producing adenomas (APA), 12 cortisol-producing adenomas (CPA), 13 nonfunctioning adrenal cortical adenomas (NFA), and 13 adrenal cortical carcinomas (CA) was investigated. Intratumoral vascular density was explored by CD34, a marker of endothelial cells, and the angiogenic status was investigated by vascular endothelial growth factor (VEGF) expression, an important angiogenic factor expressed by tumoral cells. Vascular density, quantified as the number of vessels per square millimeter, was significantly lower (P < 0.0001) in CA (110.3 +/- 27.8) than in N (336.6 +/- 14.5), APA (322.8 +/- 19.1), CPA (288.5 +/- 14.3), and NFA (274.2 +/- 19.8). VEGF expression, calculated as the percentage of positive cells, was significantly greater (P < 0.0001) in CA (85.3 +/- 2.1) than in APA (56.5 +/- 7.5), CPA (38.5 +/- 7.0), N (33.1 +/- 6.1), and NFA (0.76 +/- 0.6). In APA, a negative relation between CD34 and plasma renin activity (P < 0.0002) and a positive association between CD34 and aldosterone levels (P < 0.05) was found. In conclusion, the angiogenic phenotype of CA is characterized by VEGF overexpression but low vascularization, a finding suggesting a dissociation between angiogenic potential and neoangiogenic capabilities of these tumors. The lack of VEGF expression in NFA and the close association between angiogenesis and functional status in APA also suggest a possible influence of the angiogenic phenotype on hormonal secretion of these endocrine tumors.

Pathological and immunohistochemical studies of choroid plexus carcinoma of the dog

Choroid plexus carcinomas in four dogs (three male, one female) aged small middle 2.5 to 10 years, were examined by light microscopy and immunohistochemistry. The dogs showed progressive neurological signs including ataxia, seizures, vestibular disease and cranial nerve deficits, lasting for several months in some cases. Primary tumours were localized in the lateral (one case), third (one case), and fourth (two cases) ventricles. Hydrocephalus was evident at post-mortem examination in one case. In two cases the neoplastic cells closely resembled the structure of normal choroid plexus, with a distinct papillary pattern, composed of well-differentiated columnar epithelium. In the other two cases, cellular pleomorphism, nuclear atypia, increased mitotic activity and necrosis were observed. In all cases, dissemination of neoplastic cell clusters was detected within the subarachnoid space or the ventricular cavity. Immunohistochemical examination showed a multifocal labelling pattern for pankeratin and cytokeratin AE1 and diffuse vimentin positivity in poorly differentiated tumours. Well-differentiated choroid plexus carcinomas showed multifocal immunoreactivity for cytokeratin AE3, multifocal to diffuse immunoreactivity for vimentin and occasional positivity for carcinoembryonic antigen. Epithelial membrane antigen, Ber EP4 and S-100 were negative in all cases. Glial fibrillary acidic protein labelling occurred only in a single, poorly differentiated tumour. Occasional reactions for proliferating cell nuclear antigen and MIB-1 were seen in two cases. It was concluded that at least two morphological and possibly phenotypic subtypes (well-differentiated and anaplastic) of choroid plexus carcinoma of the dog could be identified.