VEGF concentration from plasma-activated platelets rich correlates with microvascular density and grading in canine mast cell tumour spontaneous model

Immunohistochemical, pharmacovigilance, and omics analyses reveal the involvement of ATP-sensitive K+ channel subunits in cancers: role in drug-disease interactions

Background: ATP-sensitive-K+ channels (KATP) are involved in diseases, but their role in cancer is poorly described. Pituitary macroadenoma has been observed in Cantu' syndrome (C.S.), which is associated with the gain-of-function mutations of the ABCC9 and KCNJ8 genes. We tested the role of the ABCC8/Sur1, ABCC9/Sur2A/B, KCNJ11/Kir6.2, and KCNJ8/Kir6.1 genes experimentally in a minoxidil-induced renal tumor in male rats and in the female canine breast cancer, a spontaneous animal model of disease, and in the pharmacovigilance and omics databases. Methods: We performed biopsies from renal tissues of male rats (N = 5) following a sub-chronic high dosing topical administration of minoxidil (0.777-77.7 mg/kg/day) and from breast tissues of female dogs for diagnosis (N = 23) that were analyzed by immunohistochemistry. Pharmacovigilance and omics data were extracted from EudraVigilance and omics databases, respectively. Results: An elevated immunohistochemical reactivity to Sur2A-mAb was detected in the cytosol of the Ki67+/G3 cells other than in the surface membrane in the minoxidil-induced renal tumor and the breast tumor samples. KCNJ11, KCNJ8, and ABCC9 genes are upregulated in cancers but ABCC8 is downregulated. The Kir6.2-Sur2A/B-channel opener minoxidil showed 23 case reports of breast cancer and one case of ovarian cancer in line with omics data reporting, respectively, and the negative and positive prognostic roles of the ABCC9 gene in these cancers. Sulfonylureas and glinides blocking the pancreatic Kir6.2-Sur1 subunits showed a higher risk for pancreatic cancer in line with the positive prognostic role of the ABCC8 gene but low risks for common cancers. Glibenclamide, repaglinide, and glimepiride show a lower cancer risk within the KATP channel blockers. The Kir6.2-Sur1 opener diazoxide shows no cancer reactions. Conclusion: An elevated expression of the Sur2A subunit was found in proliferating cells in two animal models of cancer. Immunohistochemistry/omics/pharmacovigilance data reveal the role of the Kir6.1/2-Sur2A/B subunits as a drug target in breast/renal cancers and in C.S.

Inflammatory Related Reactions in Humans and in Canine Breast Cancers, A Spontaneous Animal Model of Disease

Inflammatory cells are emerging markers in various cancers in human trials. The relationship between the inflammatory cells response, cancer grade, and progression has been investigated experimentally in a spontaneous canine model of breast cancer and in the unselected population (18–64 years.o.) under anti-HER2 treatments that represent the most prevalent population in this cancer type. The canine data (N samples = 101) were collected retrospectively for diagnosis in our regional area and evaluated by immunohistochemistry and haemato-chemistry. The inflammatory and immune-related adverse reactions (ADR) in humans were evaluated using EudraVigilance. The “Proportional Reporting Ratio” (PRR) of the mabs was calculated for each ADR with values >2 indicative of high risk. In dogs, we found elevated immunostaining of CD68-macrophages in the lymph node of the aggressive cancer G3 and infiltrating CD20+-lymphocyte. A high density of CD20 + lymphocytes was observed in G1 and a decrease in the density was observed with the histological degree of the tumors. The animals with the sample in G1 showed reduced serum platelet and neutrophil count and elevated lymphocytes and the opposite in severely affected animals. Inflammatory reactions with edema, skin reactions, extravasation, loss of effectiveness, and platelet count decrease (PRR > 13) were found with trastuzumab emtansine in humans, in the absence of immune system reactions. Trastuzumab i.v.-s.c. showed immune system reactions, loss of effectiveness, intolerances with drug withdrawal, technological issues (PRR > 7), and neutrophil count decrease reports. These reactions were less frequently reported for pertuzumab i.v. Case reports of platelet and neutrophil count decrease were not associated with disease progression with a better outcome in humans as in canine breast cancer. Therefore, infiltrating CD68-macrophages are associated with G3, while infiltrating CD20⁺ and elevated serum lymphocytes in parallel with reduced platelet and neutrophil count play a favorable role in human and canine breast cancer.

Differences in Post-ischemic Motor Recovery and Angiogenesis of MCAO Rats Following Electroacupuncture at Different Acupoints

BACKGROUND

Electroacupuncture (EA) can promote nerve and vascular regeneration, confer neuroprotection, inhibit apoptosis and inflammatory reactions, reduce oxidative stress injury, regulate neurochemicals and inhibit the formation of brain oedema in cerebral ischemic. However, the precise site of EA stimulation in the treatment of cerebral ischemic is unclear.

OBJECTIVE

In the present study, we investigated the effect of EA at the acupoints of different meridians in motor function recovery and the involvement of Vascular Endothelial Growth Factor (VEGF), phosphorylated Protein Kinase B (P-Akt), phosphorylated endothelial nitric oxide synthase (p-eNOS) and Platelet Endothelial Cell Adhesion Molecule-1(CD31) were examined in the peri-infarction cortex of rats.

METHODS

The Middle cerebral artery occlusion (MCAO) model or sham surgery was performed in a total of Ninety male Sprague-Dawley rats. Rats were randomly divided into five groups: a sham group, a middle cerebral artery occlusion (MCAO) group, a Yang meridian group, a Yin meridian group and a combined Yang and Yin meridian group. EA stimulus was given during the middle cerebral artery occlusion. The neurobehavioural function was measured using Modified Neurological Severity Scores (mNSS), the rotarod test and the ladder rung walking test, and the protein expression of VEGF, P-Akt, p-eNOS in the peri-infarction cortex was detected by Western blot. Immunofluorescence was used to measure the vascular density of the peri-infarction cortex.

RESULTS

EA at different meridian acupoints has no effect on the infarction volume, while EA at Yin meridian acupoints significantly promoted neurobehavioural functional recovery, increased the vascular density and enhanced protein kinase B/Endothelial nitric oxide synthase (Akt/eNOS) phosphorylation and VEGF expression.

CONCLUSION

In the early stage of stroke, EA at Yin meridian acupoints can improve neurobehavioural functional recovery and the mechanism of this effect may be related to the enhanced expression of VEGF, P-Akt and p-eNOS in the peri-infarction cortex of rats.

Prognostic value of immunohistochemical markers in canine cutaneous mast cell tumours: A systematic review and meta-analysis

Histological grading systems remain cornerstones in the prognosis of canine cutaneous mast cell tumours (MCTs), but the distinct biological behaviour of each tumour often necessitates the use of complementary markers. Although a plethora of immunohistochemical markers have been proposed as prognostic factors, few are presently applied in routine diagnosis. This systematic review and meta-analysis was designed to establish which immunohistochemical markers have verifiable prognostic value for cutaneous MCTs in dogs. A Boolean search of five databases identified 200 articles for screening, of which 73 were selected for full-text assessment and 24 ultimately included in the systematic review. Odds Ratio (OR) was adopted as the summary measure for subsequent meta-analysis but only 15 articles, relating to the immunomarkers Ki-67 (9), KIT (5), and BAX (2), provided either a value for OR or sufficient data to calculate this statistic. Meta-analysis verified that canine cutaneous MCTs with elevated expression of Ki-67 or BAX, as well aberrant immuno-expression of KIT, showed an increased odds of death, with respective OR values of 11.2 (95% CI 6.3-20.0; p < .01), 9.9 (95% CI 1.3-73.6; p = .03), and 4.1 (95% CI 1.1-15.3; p = .03). Despite KIT, Ki67, and BAX arise as suitable prognostic factor for canine MCTs, this study highlighted the lack of important clinical and statistical data in many published articles, rendering it impossible to complete the meta-analysis of several potentially valuable immunohistochemical markers.

Mast Cells Positive for c-Kit Receptor and Tryptase Correlate with Angiogenesis in Cancerous and Adjacent Normal Pancreatic Tissue

Background: Mast cells (MCs) contain proangiogenic factors, in particular tryptase, associated with increased angiogenesis in several tumours. With special reference to pancreatic cancer, few data have been published on the role of MCs in angiogenesis in both pancreatic ductal adenocarcinoma tissue (PDAT) and adjacent normal tissue (ANT). In this study, density of mast cells positive for c-Kit receptor (MCDP-c-KitR), density of mast cells positive for tryptase (MCDPT), area of mast cells positive for tryptase (MCAPT), and angiogenesis in terms of microvascular density (MVD) and endothelial area (EA) were evaluated in a total of 45 PDAT patients with stage T_2–3N_0–1M₀. Results: For each analysed tissue parameter, the mean ± standard deviation was evaluated in both PDAT and ANT and differences were evaluated by Student’s t-test (p ranged from 0.001 to 0.005). Each analysed tissue parameter was then correlated to each other one by Pearson t-test analysis (p ranged from 0.01 to 0.03). No other correlation among MCDP-c-KitR, MCDPT, MCAPT, MVD, EA and the main clinical–pathological characteristics was found. Conclusions: Our results suggest that tissue parameters increased from ANT to PDAT and that mast cells are strongly associated with angiogenesis in PDAT. On this basis, the inhibition of MCs through tyrosine kinase inhibitors, such as masitinib, or inhibition of tryptase by gabexate mesylate may become potential novel antiangiogenetic approaches in pancreatic cancer therapy.

The role of mast cells in human skin cancers

Mast cells (MCs) are immune cells derived from myeloid lineage present in all classes of vertebrates and have emerged preceding much time the development of adaptive immunity. MCs are involved in inflammatory processes, allergic reactions, and host responses to parasites and bacteria infectious diseases. MCs are located at the host-environment interface, at many sites of initial antigen entry, including skin, lung and gastrointestinal tract, and have part of a protective mechanism. Skin has an important role in protecting the host from invasion both as physical barriers and by employing an intricate network of resident immune and non-immune cells include macrophages, T and B lymphocytes, MCs, neutrophils, eosinophils, and Langerhans cells. In this review we discussed the role of MCs in human skin cancers.

Microvascular Density, Endothelial Area, and Ki-67 Proliferative Index Correlate Each Other in Cat Post-Injection Fibrosarcoma

Soft tissue sarcomas are a large group of different tumor types both in humans and in animals. Among them, fibrosarcoma is the most frequent malignant mesenchymal tumoral form in cats, representing up to 28% of all cat skin tumors, while human fibrosarcoma, fortunately, only represents 5% of all sarcomas and 0.025% of the world-wide burden of tumors. This low incidence in humans leads to consideration of this group of tumoral diseases as rare, so therapeutic options are few due to the difficulty of starting clinical trials. In this context, the identification of research models for fibrosarcomas could be of great interest to deepen knowledge in this field and recognize new or possible biological pathways involved in tumor progression and metastasis. Angiogenesis is considered a fundamental scattering cause of tumor aggressiveness and progression in all forms of cancer, but only a few research parameters were developed and reported to express them quantitatively and qualitatively. The role in angiogenesis of microenvironmental stromal cells, such as fibroblasts, lymphocytes, mast cells, and macrophages, was largely demonstrated since this topic was first approached, while quantification of new vessels and their blood capacity in tumoral area is a relatively recent approach that could be well developed thanks to expertise in immunohistochemistry and image analysis. In this paper, a crossing study evaluating microvascular density (MVD), endothelial area (EA), and Ki-67 proliferative index was reported for a series of formalin-fixed and paraffin-embedded tissue samples from 99 cat patients, affected by cat post-injection fibrosarcoma, by using a till ×400 magnification light microscopy. We aim to demonstrate that cat pets may be considered a useful animal model for better studying the correspondent human diseases and we report, for the first time to our knowledge, experimental data in terms of correlation among MVD, EA, and Ki-67 strictly involved in aggressiveness and tumoral progression.

Immunohistochemical Expression of Vascular Endothelial Growth Factor as a Prognostic Marker for Canine Mast Cell Tumors

Strong to moderate vascular endothelial growth factor (VEGF) expression may be a negative prognostic factor in canine mast cell tumors (MCTs). This study set out to determine the prognostic value of combined analysis of VEGF-A immunoreactivity, clinical presentation, patient staging, and tumor histologic grade in canine MCTs. In this study, intense VEGF staining was significantly associated with decreased survival (P = .025). Immunohistochemical expression of VEGF is not routinely employed as a prognostic factor in canine MCT workup. However, results of this study support the inclusion of this marker in the MCT prognostic panel. Investigation of VEGF expression may assist in the development of anti-VEGF drugs.

Thymidine Phosphorylase Expression and Microvascular Density Correlation Analysis in Canine Mammary Tumor: Possible Prognostic Factor in Breast Cancer

Purpose: The thymidine phosphorylase (TP) is a key enzyme involved in the metabolism of pyrimidines. Inhibition or downregulation of this enzyme causes accumulation of metabolites with consequences in DNA replication. TP regulates angiogenesis and chemotactic activity of endothelial cells. Different studies showed the presence of TP upregulation in human cancer but the correlation between TP expression and the microvascular density (MVD) in canine mammary tumors is unknown. The aim of this study was to investigate a possible correlation between the MVD and TP expression in tumor cells of canine mammary tumors of different degree of severity (G1–G3) by immunohistochemical analysis.

Methods: Sixty-eight samples of spontaneous mammary neoplasia of 5–12 cm in diameter were collected from purebred and mixed-breed dogs (mean aged = 9.5 ± 7), not subject to chemotherapy treatments in veterinary clinics. Histopathological analysis and immunostaining were performed.

Results: Carcinoma simple samples have been classified as 72.06% of tubule-papillary, 20.59% cysto-papillary, and 7.35% tubular carcinomas. Immunostainings revealed a marked cytoplasmic expression of TP in 30.88% of samples, mild in 32.35%, weaker in 22.07%, and negative in 14.70%. The correlation analysis and two-way ANOVA showed a linear correlation between MVD and TP with a coefficient of correlation (r) > 0.5 (p < 0.05) in G2 and G3. No correlation between variables was found in G1.

Conclusions: These findings suggest that cytoplasmic TP overexpression is correlated with microvascular density in canine mammary tumors, in severe grade, and it can be a potential prognostic factor in breast cancer.

An evaluation of masitinib for treating systemic mastocytosis

Introduction: Systemic Mastocytosis (SM) is a complex family of rare diseases, against which pharmacological therapies are still very few. It is a c-kit driven disease, whose disregulation leads to uncontrolled activation and proliferation of mast cells (MCs) with consequent release of effector molecules which are responsible for its clinical manifestations. Areas covered: Masitinib is a relatively new potential drug against SM and its chemical structure strictly derives from imatinib, the first tyrosine kinase inhibitor which entered the pharmaceutical market about 15 years ago. In this review, the authors present masitinib in all its properties, from chemistry to pharmacology and toxicity to its potential clinical application in SM, focusing the discussion on the few clinical trials in which it has been involved, with a particular attention on the still open challenge to determine how to measure the response to therapy. Expert opinion: In spite of their similarity in chemistry and biological activity against submolecular targets, masitinib is much more selective towards c-kit receptors than other tyrosine kinases, such as Bcl-Abl. Furthermore, its ability to inhibit degranulation, cytokine production and MCs migration from bone marrow gives it a great chance to become an important therapeutic option for selected SM patients.

The Correlation of Clinicopathological Findings and Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios in Papillary Thyroid Carcinoma

Objectives:

Inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been recently introduced as potential biomarkers for tumor pathogenesis, development and prognosis in solid tumors. Our aim was to assess the correlation of clinicopathological features and NLR and PLR in patients with papillary thyroid carcinoma (PTC).

Methods:

A total of 201 papillary thyroid carcinoma patients were divided into groups with a cut-off preoperative median NLR and PLR value of 1,92 and 123.9, respectively. The correlation of NLR and PLR and clinicopathological features including age, tumor size, extra-thyroidal extension, thyroid capsule invasion, surgical margin positivity, multifocality, bilaterality of the patients were analyzed.

Results:

The mean NLR and PLR were 2.11±0.94, 129.69±42.81, respectively. Larger tumor size and higher positivity of extra-thyroidal spread were correlated with higher NLR values. No significant relationship was found between NLR and age, presence of thyroid capsule invasion, surgical margin positivity, multifocality, bilaterality, and lymph node metastasis. Also no significant association was observed between the clinicopathological features and PLR.

Conclusion:

High NLR was found to correlate with tumor size and extra-thyroidal extension. NLR may be used as a marker to determine the clinical behavior of disease in patients with papillary thyroid carcinoma (PTC).

Oncolytic Viruses for Canine Cancer Treatment

Oncolytic virotherapy has been investigated for several decades and is emerging as a plausible biological therapy with several ongoing clinical trials and two viruses are now approved for cancer treatment in humans. The direct cytotoxicity and immune-stimulatory effects make oncolytic viruses an interesting strategy for cancer treatment. In this review, we summarize the results of in vitro and in vivo published studies of oncolytic viruses in different phases of evaluation in dogs, using PubMed and Google scholar as search platforms, without time restrictions (to date). Natural and genetically modified oncolytic viruses were evaluated with some encouraging results. The most studied viruses to date are the reovirus, myxoma virus, and vaccinia, tested mostly in solid tumors such as osteosarcomas, mammary gland tumors, soft tissue sarcomas, and mastocytomas. Although the results are promising, there are issues that need addressing such as ensuring tumor specificity, developing optimal dosing, circumventing preexisting antibodies from previous exposure or the development of antibodies during treatment, and assuring a reasonable safety profile, all of which are required in order to make this approach a successful therapy in dogs.

Applications of Platelet-Rich Plasma in Lymphedema

Platelet-rich plasma (PRP) is an autologous concentrated preparation of human platelets contained in a small volume of plasma that is characterized by hemostatic and tissue-repairing effects. Being enriched by various kinds of growth factors, and their tissue-repairing effects have made them the focus of attention for use in tissue regeneration. PRP has been safely used and documented in many different fields, including orthopedics, sports injuries, dental and periodontal surgery, and cosmetic, plastic, cardiovascular, general, and maxillofacial surgery. The current evidence obtained from in vitro and animal studies pointed out that PRP may potentially be used to regenerate injured lymphatic vessels to treat or prevent lymphedema. Therefore, we have reviewed existing literature on the clinical uses of PRP in lymphedema and inquired whether there is enough evidence to support the use of PRP in clinical practice as a treatment option. In contrast to in vitro and animal models, there is no clinical trial regarding the use of PRP in lymphedema treatment. Only two animal studies matched to our research yielded positive and promising results in terms of the potential role of PRP in future for lymphedema therapies. In the light of these findings, it is clear that this is an important issue that should be studied in greater depth to clarify the efficacy of PRP in the management of lymphedema.

Immuno-PCR in cancer and non-cancer related diseases: a review

Polymerase chain reaction-amplified immunoassay (immuno-PCR, iPCR) is a method that combines the specificity of an immunological detection method and the sensitivity of a nucleic acid amplification method. In this way, immuno-PCR uses a minimum amount of sample, and allows the detection of rare diseases and those diseases in very early stage (i.e. infectious diseases, degenerative disorders, or neoplastic diseases). The present review was aimed to describe this new methodology and applications to the early detection of cancer and non-cancer related diseases, and discuss about the possibility to detect diverse biomarkers of oncology disorders, such as breast, gastric, colorectal and nasopharynx cancer, and other factors related to the growth of the neoplastic disease.

Receptor Tyrosine Kinase Expression Profiles in Canine Cutaneous and Subcutaneous Mast Cell Tumors

The receptor tyrosine kinase (RTK) KIT is a major focus of current research into canine mast cell tumors (MCTs). Little is known about the role of other RTKs, such as vascular endothelial growth factor receptors (VEGFRs) and platelet-derived growth factor receptors (PDGFRs). These RTKs are dysregulated in many human and animal cancers and are key regulators of tumor angiogenesis. The aims of this study were to assess the expression and activation (phosphorylation) status of KIT, VEGFR2, and PDGFR (α and β) in canine MCTs and to examine associations with various clinical outcomes. c- KIT mutational status and KIT cellular localization pattern were also evaluated for these tumors. Twenty-seven MCTs, consisting of 5 subcutaneous and 22 cutaneous tumors, from 25 dogs were evaluated. MCT biopsies, cultured mast cells, and skin from the surgical margin were analyzed through Western blotting. MCT biopsies were also used for KIT immunohistochemical labeling and polymerase chain reaction for c- KIT mutational analysis. MCT had heterogeneous expression profiles for all 3 RTKs, which varied in intensity and activation status. Statistical analyses showed phosphorylated KIT, VEGFR2, and KIT cellular localization to be predictive of decreased survival time, disease-free interval, and increased metastatic rate. Expression of VEGFR2 and KIT diffuse cytoplasmic labeling were also significantly associated with increased rate of local recurrence. The results of the study show that phosphorylated KIT, KIT, VEGFR2, and PDGFRβ, in addition to KIT localization, may be valuable prognostic determinants in MCTs and should be further studied to improve diagnostic and therapeutic modalities.

Cytokine Regulation of Microenvironmental Cells in Myeloproliferative Neoplasms

The term myeloproliferative neoplasms (MPN) refers to a heterogeneous group of diseases including not only polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), but also chronic myeloid leukemia (CML), and systemic mastocytosis (SM). Despite the clinical and biological differences between these diseases, common pathophysiological mechanisms have been identified in MPN. First, aberrant tyrosine kinase signaling due to somatic mutations in certain driver genes is common to these MPN. Second, alterations of the bone marrow microenvironment are found in all MPN types and have been implicated in the pathogenesis of the diseases. Finally, elevated levels of proinflammatory and microenvironment-regulating cytokines are commonly found in all MPN-variants. In this paper, we review the effects of MPN-related oncogenes on cytokine expression and release and describe common as well as distinct pathogenetic mechanisms underlying microenvironmental changes in various MPN. Furthermore, targeting of the microenvironment in MPN is discussed. Such novel therapies may enhance the efficacy and may overcome resistance to established tyrosine kinase inhibitor treatment in these patients. Nevertheless, additional basic studies on the complex interplay of neoplastic and stromal cells are required in order to optimize targeting strategies and to translate these concepts into clinical application.

Defining the effects of storage on platelet bioenergetics: The role of increased proton leak

The quality of platelets decreases over storage time, shortening their shelf life and potentially worsening transfusion outcomes. The changes in mitochondrial function associated with platelet storage are poorly defined and to address this we measured platelet bioenergetics in freshly isolated and stored platelets. We demonstrate that the hypotonic stress test stimulates both glycolysis and oxidative phosphorylation and the stored platelets showed a decreased recovery to this stress. We found no change in aggregability between the freshly isolated and stored platelets. Bioenergetic parameters were changed including increased proton leak and decreased basal respiration and this was reflected in a lower bioenergetic health index (BHI). Mitochondrial electron transport, measured in permeabilized platelets, showed only minor changes which are unlikely to have a significant impact on platelet function. There were no changes in basal glycolysis between the fresh and stored platelets, however, glycolytic rate was increased in stored platelets when mitochondrial ATP production was inhibited. The increase in proton leak was attenuated by the addition of albumin, suggesting that free fatty acids could play a role in increasing proton leak and decreasing mitochondrial function. In summary, platelet storage causes a modest decrease in oxidative phosphorylation driven by an increase in mitochondrial proton leak, which contributes to the decreased recovery to hypotonic stress.

Preclinical Testing Oncolytic Vaccinia Virus Strain GLV-5b451 Expressing an Anti-VEGF Single-Chain Antibody for Canine Cancer Therapy

Virotherapy on the basis of oncolytic vaccinia virus (VACV) strains is a novel approach for canine cancer therapy. Here we describe, for the first time, the characterization and the use of VACV strain GLV-5b451 expressing the anti-vascular endothelial growth factor (VEGF) single-chain antibody (scAb) GLAF-2 as therapeutic agent against different canine cancers. Cell culture data demonstrated that GLV-5b451 efficiently infected and destroyed all four tested canine cancer cell lines including: mammary carcinoma (MTH52c), mammary adenoma (ZMTH3), prostate carcinoma (CT1258), and soft tissue sarcoma (STSA-1). The GLV-5b451 virus-mediated production of GLAF-2 antibody was observed in all four cancer cell lines. In addition, this antibody specifically recognized canine VEGF. Finally, in canine soft tissue sarcoma (CSTS) xenografted mice, a single systemic administration of GLV-5b451 was found to be safe and led to anti-tumor effects resulting in the significant reduction and substantial long-term inhibition of tumor growth. A CD31-based immuno-staining showed significantly decreased neo-angiogenesis in GLV-5b451-treated tumors compared to the controls. In summary, these findings indicate that GLV-5b451 has potential for use as a therapeutic agent in the treatment of CSTS.

In vivo model for mastocytosis: A comparative review

Human mastocytosis are heterogeneous group of neoplastic diseases characterized by a different degree of uncontrolled mast cell (MC) proliferation and activation. Interestingly, human mastocytosis share several biological and clinical features with canine mast cell disorders, so called canine mast cell tumors (CMCTs). These CMCTs are the most common spontaneous cutaneous tumors found in dogs representing a valid model to study neoplastic mast cell disorders. It has been discovered that the pathological activation of c-Kit receptor (c-KitR), expressed by MCs, has been involved in the pathogenesis of neoplastic MC disorders. In this review we have focused on human mastocytosis in terms of: (i) epidemiology and classification; (ii) pathogenesis at molecular levels; (iii) clinical presentation. In addition, we have summarized animal models useful to study neoplastic MC disorders including CMCTs and murine transgenic models. Finally, we have revised therapeutic approaches mostly common in human and canine MCTs and novel tyrosine kinase inhibitors approved for CMCTs and recently translated in human clinical trials.

Evaluation of a new recombinant oncolytic vaccinia virus strain GLV-5b451 for feline mammary carcinoma therapy

Virotherapy on the basis of oncolytic vaccinia virus (VACV) infection is a promising approach for cancer therapy. In this study we describe the establishment of a new preclinical model of feline mammary carcinoma (FMC) using a recently established cancer cell line, DT09/06. In addition, we evaluated a recombinant vaccinia virus strain, GLV-5b451, expressing the anti-vascular endothelial growth factor (VEGF) single-chain antibody (scAb) GLAF-2 as an oncolytic agent against FMC. Cell culture data demonstrate that GLV-5b451 virus efficiently infected, replicated in and destroyed DT09/06 cancer cells. In the selected xenografts of FMC, a single systemic administration of GLV-5b451 led to significant inhibition of tumor growth in comparison to untreated tumor-bearing mice. Furthermore, tumor-specific virus infection led to overproduction of functional scAb GLAF-2, which caused drastic reduction of intratumoral VEGF levels and inhibition of angiogenesis.

In summary, here we have shown, for the first time, that the vaccinia virus strains and especially GLV-5b451 have great potential for effective treatment of FMC in animal model.

Correlation between serum tryptase, mast cells positive to tryptase and microvascular density in colo-rectal cancer patients: possible biological-clinical significance

Background

Tryptase is a serin protease stored and released from mast cells (MCs) that plays a role in tumour angiogenesis. In this study we aimed to evaluate serum tryptase levels in colo-rectal cancer (CRC) patients before (STLBS) and after (STLAS) radical surgical resection. We also evaluated mast cell density positive to tryptase (MCDPT) and microvascular density (MVD) in primary tumour tissue.

Methods

A series of 61 patients with stage B and C CRC (according to the Astler and Coller staging system) were selected. Serum blood samples were collected from patients one day before and one day after surgery. Tryptase levels were measured using the UniCAP Tryptase Fluoroenzymeimmunoassay (Pharmacia, Uppsala, Sweden). Tumour sections were immunostained with a primary anti-tryptase antibody (clone AA1; Dako, Glostrup, Denmark) and an anti CD-34 antibody (QB-END 10; Bio-Optica Milan, Italy) by means of immunohistochemistry and then evaluated by image analysis methods.

Results

The mean ± s.d. STLBS and STLAS was 5.63±2.61 µg/L, and 3.39±1.47 µg/L respectively and a significant difference between mean levels was found: p = 0.000 by t-test. The mean ± s.d. of MCDPT and MVD was 8.13±3.28 and 29.16±7.39 respectively. A strong correlation between STLBS and MVD (r = 0.83, p = 0.000); STLBS and MCDPT (r = 0.60, p = 0.003); and MCDPT and MVD (r = 0.73; p = 0.001) was found.

Conclusion

Results demonstrated higher STLBS in CRC patients, indicating an involvement of MC tryptase in CRC angiogenesis. Data also indicated lower STLAS, suggesting the release of tryptase from tumour-infiltrating MCs. Serum tryptase levels may therefore play a role as a novel bio-marker predictive of response to radical surgery. In this context tryptase inhibitors such as Gabexate and Nafamostat Mesilate might be evaluated in adjuvant clinical trials as a new anti-angiogenic approach.

c-Kit expression, angiogenesis, and grading in canine mast cell tumour: a unique model to study c-Kit driven human malignancies

Canine cutaneous mast cell tumour (CMCT) is a c-Kit driven tumour sharing similar c-Kit aberrations found in human gastrointestinal stromal tumour. CMCT is classified into three forms: well- (G1), intermediately (G2) (more benign diseases), and poorly (G3) differentiated (malignant) forms. We assess a correlation between c-Kit status, grading, and angiogenesis in CMCTs to explore their potential significance in humans. C-Kit receptor (c-KitR) expression, microvascular density (MVD), and mast cell granulated and degranulated status density (MCGD and MCDD, resp.) were analyzed in 97 CMCTs, by means of histochemistry, immunohistochemistry double staining, and image analysis system. Data showed that predominantly diffuse cytoplasmic- and predominantly focal paranuclear- (Golgi-like) c-Kit protein (PDC-c-Kit and PFP-c-Kit, resp.) expression correlate with high MVD, G3 histopathological grade, and MCDD. Moreover, predominant cell membrane-c-KitR (PCM-c-KitR) expression status correlates with low MVD, G1-G2 histopathological grade, and MCGD. These findings underline the key role of c-Kit in the biopathology of canine MCTs, indicating a link between aberrant c-Kit expression, increased angiogenesis, and higher histopathological grade. CMCT seems to be a model to study contributions of c-Kit activated MCs in tumour angiogenesis and to evaluate the inhibition of MCs activation by means of c-Kit tyrosine kinase inhibitors, currently translated in humans.

Masitinib (AB1010), from canine tumor model to human clinical development: where we are?

Masitinib mesylate (AB1010) is a novel potent and selective tyrosine kinase inhibitor, targeting mainly wild-type and mutated c-Kit receptor (c-KitR), Platelet Derived Growth Factor Receptor-alfa/beta (PDGFRa/ß), Lymphocyte-specific kinase (Lck), Lck/Yes-related protein (LYn), Fibroblast Growth Factor Receptor 3 (FGFR3) and Focal Adhesion Kinase (FAK). It is the first anticancer therapy approved in veterinary medicine for the treatment of unresectable canine mast cell tumors (CMCTs), harboring activating c-KitR mutations, at dose of 12.5mg/kg once daily. Considering its anti-proliferative action, principally given by inhibiting the MCs c-KitR anti-angiogenic pathway that leads cancer progression, and its role as chemosensitizer, masitinib is under clinical investigation in several human malignancies (Gastro-Intestinal Stromal Tumors, acute myeloid leukemia, systemic mastocytosis, pancreatic cancer, multiple myeloma, non-small cell lung cancer, melanoma, ovarian and prostate cancer), which are characterized by similar canine c-KIT proto-oncogene mutations. Here, we analyze masitinib structure activity, its pharmacokinetics compared to imatinib, the c-KitR pathway referring to the most frequent c-KIT mutations sensitive or resistant to this novel drug compared to imatinib, and masitinib safety profile. We, also, explore preclinical and clinical (completed and ongoing) trials with the aim to emphasize as this recent anti-angiogenic therapy, at first approved in CMCTs and, currently in development for the treatment of several human neoplasms, could be represent a milestone in translational oncology, in which the murine experimental model of cancer research could be integrated by canine spontaneous tumor model.

Stimulated mast cells promote maturation of myocardial microvascular endothelial cell neovessels by modulating the angiopoietin-Tie-2 signaling pathway

Angiopoietin (Ang)-1 and Ang-2 interact in angiogenesis to activate the Tie-2 receptor, which may be involved in new vessel maturation and regression. Mast cells (MCs) are also involved in formation of new blood vessels and angiogenesis. The present study was designed to test whether MCs can mediate angiogenesis in myocardial microvascular endothelial cells (MMVECs). Using a rat MMVEC and MC co-culture system, we observed that Ang-1 protein levels were very low even though its mRNA levels were increased by MCs. Interestingly, MCs were able to enhance migration, proliferation, and capillary-like tube formation, which were associated with suppressed Ang-2 protein expression, but not Tie-2 expression levels. These MCs induced effects that could be reversed by either tryptase inhibitor [N-tosyl-L-lysine chloromethyl ketone (TLCK)] or chymase inhibitor (N-tosyl-L-phenylalanyl chloromethyl ketone), with TLCK showing greater effects. In conclusion, our data indicated that MCs can interrupt neovessel maturation via suppression of the Ang-2/Tie-2 signaling pathway.

Tyrosine kinase inhibitors (TKIs) in human and pet tumours with special reference to breast cancer: a comparative review

Tyrosine kinase receptors (TKRs) play a key role in tumour cell proliferation and survival since they are involved in endothelial cell activation leading to tumour neoangiogenesis. In particular, vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptor (PDGFR), stem cell factor receptor (c-KitR), and colony-stimulating factor 1 (CSF-1) are overexpressed or constitutively activated in human and pet malignancies. A variety of small molecule inhibitors targeting specific tyrosine kinases (known as tyrosine kinase inhibitors or TKIs) have recently been approved, or are under investigation, for the treatment of human cancer. TKI application in animal cancer is however relatively recent. This review aims to illustrate the major aspects of tyrosine kinase dysfunctions, with special regard to human and animal cancer of the mammary gland, providing an update on the background of the anti-angiogenic and anti-neoplastic properties of TKIs in human and veterinary cancer.

A model of study for human cancer: Spontaneous occurring tumors in dogs. Biological features and translation for new anticancer therapies

Murine cancer models have been extremely useful for analyzing the biology of pathways involved in cancer initiation, promotion, and progression. Interestingly, several murine cancer models also exhibit heterogeneity, genomic instability and an intact immune system. However, they do not adequately represent several features that define cancer in humans, including long periods of latency, the complex biology of cancer recurrence and metastasis and outcomes to novel therapies. Therefore, additional models that better investigate the human disease are needed. In the pet population, with special references to the dog, cancer is a spontaneous disease and dogs naturally develop cancers that share many characteristics with human malignancies. More than 40 years ago, optimization of bone marrow transplantation protocols was undertaken in dogs and recently novel targeted therapies such as liposomal muramyl tripeptide phosphatidylethanolamine and several tyrosine kinase inhibitors, namely masitinib (AB1010) and toceranib phosphate (SU11654), have been developed to treat dog tumors which have then been translated to human clinical trials. In this review article, we will analyze biological data from dog tumors and comparative features with human tumors, and new therapeutic approaches translated from dog to human cancer.

Tryptase-positive mast cells and angiogenesis in keloids: a new possible post-surgical target for prevention

Literature data indicate that mast cells (MCs) are involved in angiogenesis through the release of several pro-angiogenetic factors among which tryptase, a serine protease stored in MC granules, is one of the most active. However, no data are available concerning the role of MCs during keloids' angiogenesis. In this study, we evaluated the correlations of the number of MCs positive to tryptase (MCDPT) and microvascular density (MVD) within a series of 15 keloids and 10 normotrophic scars, by means of immunohistochemistry and image analysis methods. Data demonstrated a significant difference of MVD and MCDPT between keloids and normotrophic scars and a significant correlation between MVD and MCDPT in keloids. Our results suggest that tryptase-positive MCs might play a key role in keloids' angiogenesis. In this context, several tryptase inhibitors might be clinically evaluated as a possible new anti-angiogenetic approach to prevent keloid formation after surgery.

Virotherapy of canine tumors with oncolytic vaccinia virus GLV-1h109 expressing an anti-VEGF single-chain antibody

Virotherapy using oncolytic vaccinia virus (VACV) strains is one promising new strategy for cancer therapy. We have previously reported that oncolytic vaccinia virus strains expressing an anti-VEGF (Vascular Endothelial Growth Factor) single-chain antibody (scAb) GLAF-1 exhibited significant therapeutic efficacy for treatment of human tumor xenografts. Here, we describe the use of oncolytic vaccinia virus GLV-1h109 encoding GLAF-1 for canine cancer therapy. In this study we analyzed the virus-mediated delivery and production of scAb GLAF-1 and the oncolytic and immunological effects of the GLV-1h109 vaccinia virus strain against canine soft tissue sarcoma and canine prostate carcinoma in xenograft models. Cell culture data demonstrated that the GLV-1h109 virus efficiently infect, replicate in and destroy both tested canine cancer cell lines. In addition, successful expression of GLAF-1 was demonstrated in virus-infected canine cancer cells and the antibody specifically recognized canine VEGF. In two different xenograft models, the systemic administration of the GLV-1h109 virus was found to be safe and led to anti-tumor and immunological effects resulting in the significant reduction of tumor growth in comparison to untreated control mice. Furthermore, tumor-specific virus infection led to a continued production of functional scAb GLAF-1, resulting in inhibition of angiogenesis. Overall, the GLV-1h109-mediated cancer therapy and production of immunotherapeutic anti-VEGF scAb may open the way for combination therapy concept i.e. vaccinia virus mediated oncolysis and intratumoral production of therapeutic drugs in canine cancer patients.

Trans-arterial chemoembolization as a therapy for liver tumours: New clinical developments and suggestions for combination with angiogenesis inhibitors

The liver is the primary site of metastases for many malignancies. Gastrointestinal cancers are especially prone to spread to the liver and other tumours, as breast cancer and melanoma often spread to the liver. On the other hand, hepatocellular cancer (HCC) is the fifth most common malignancy in the world due to its common etiology from chronic liver damage caused by hepatitis or cirrhosis. Treatments of liver tumours vary according to histology and liver invasion and until now trans-arterial chemoembolization (TACE) has represented a main approach in the therapy of liver tumours. This review takes into consideration: (i) the background to utilizing TACE in liver tumours; (ii) TACE methods and the biological rationale for utilizing chemotherapeutic agents coated to a new micro-particle such as DC-Beads and HepaSphere; (iii) clinical experiences employing TACE in different liver tumours; (iv) the pivotal role of angiogenesis and hypoxia-induced angiogenesis following TACE with special references to HCC. Finally, the rationale for the combination of TACE with angiogenesis inhibitors is also discussed.

Vascular endothelial growth factor concentrations from platelets correlate with tumor angiogenesis and grading in a spontaneous canine non-Hodgkin lymphoma model

Published data strongly suggest that tumor progression and malignancy are associated with increased angiogenesis. However, no data have been published concerning the relationship between microvascular density (MVD), tumor cytosol, and blood vascular endothelial growth factor (VEGF) concentrations in canine non-Hodgkin lymphoma (C-NHL), a neoplasm that shares biological and clinical characteristics with human NHL. We have evaluated MVD and tumor cytosol, serum (S), platelet-poor plasma (P-PP), plasma-activated platelet rich (P-APR) VEGF concentration in a series of 63 B-cells C-NHL by means of immunohistochemistry and enzyme-linked immuno-sorbent assay (ELISA) detection of VEGF. We found that MVD, VEGF from cytosol, and VEGF from P-APR are significantly correlated (p ranging from 0.001 to 0.003) and that these parameters paralleled with the malignancy degree of NHL. Accordingly, spontaneous C-NHL seems to be an interesting model to study the role of angiogenesis as interspecies pathway of tumor malignancy and we suggest that VEGF from P-APR might be a novel useful circulating bio-marker of tumor angiogenesis.

Impact of pretreatment hematologic profile on survival of colorectal cancer patients

Pretreatment hematologic abnormalities have been reported to have prognostic value in patients with solid tumors. The aim of our study was to determine the prevalence of abnormalities in the hematologic profile in patients with colorectal cancer before treatment and to evaluate if such a profile could be used for prognostic evaluations. We identified all patients in Cancer Center of Sun Yat-Sen University who were diagnosed as colorectal cancers between May 2005 and August 2009. All subjects were investigated regarding levels of white blood cells, platelets, and hemoglobin concentration. Survival was compared by using the log-rank test on the Kaplan-Meier life table. Multivariate Cox regression analysis was used to evaluate if the pretreatment hematologic profile was independent prognostic factor. We identified 363 patients with colorectal cancer and 315 patients with benign diseases for the final analysis. The percentages of leukocytosis, anemia, and thrombocytosis were significantly higher in colorectal cancer patients than in patients with benign diseases. Univariate analysis showed that advanced tumor stages, leukocytosis, anemia, thrombocytosis, and low histological grade were all significantly associated with shorter survival. The multivariate Cox analysis revealed that low histological grade, tumor stage, pretreatment anemia, and thrombocytosis remained independent prognostic variables for survival. The cumulative effect of anemia and thrombocytosis yielded shorter survival. Anemia and thrombocytosis can be considered as useful prognostic markers in patients with colorectal cancer.

Antiangiogenic and antitumor effects of IMMUNEPOTENT CRP in murine melanoma

BACKGROUND

Skin cancers are common, and there has recently been a dramatic increase in their incidence, particularly in the occurrence of melanoma. Furthermore, relapse after curative surgical treatment of melanoma remains a significant clinical challenge and accounts for most of the mortality of this disease.

OBJECTIVE

The aim of this study was to determine whether IMMUNEPOTENT CRP affects B16F10 melanoma cells and tumors growth and vascular endothelial growth factor (VEGF) production in vivo and in vitro.

METHODS

B16F10 cells and B16F10-inoculated mice were treated with different concentrations of IMMUNEPOTENT CRP. Outcomes were then evaluated using MTT, TUNEL, Caspase-3, senescence, ELISA and colorimetric assays. Parameters related to survival and tumor weight were also assessed.

RESULTS

IMMUNEPOTENT CRP decreased the viability of B16F10 cells by increasing apoptosis of the treated cells, and VEGF production was decreased both in vitro and in vivo. Furthermore, treatment prevented metastasis, delayed the appearance of tumors, decreased tumor weight and improved the survival of tumor-bearing mice.

DISCUSSION

These observations suggest that IMMUNEPOTENT CRP can be used to suppress growth and metastasis by using targeting proteins such as VEGF.

Platelet alpha-granules: basic biology and clinical correlates

alpha-Granules are essential to normal platelet activity. These unusual secretory granules derive their cargo from both regulated secretory and endocytotic pathways in megakaryocytes. Rare, inheritable defects of alpha-granule formation in mice and man have enabled identification of proteins that mediate cargo trafficking and alpha-granule formation. In platelets, alpha-granules fuse with the plasma membrane upon activation, releasing their cargo and increasing platelet surface area. The mechanisms that control alpha-granule membrane fusion have begun to be elucidated at the molecular level. SNAREs and SNARE accessory proteins that control alpha-granule secretion have been identified. Proteomic studies demonstrate that hundreds of bioactive proteins are released from alpha-granules. This breadth of proteins implies a versatile functionality. While initially known primarily for their participation in thrombosis and hemostasis, the role of alpha-granules in inflammation, atherosclerosis, antimicrobial host defense, wound healing, angiogenesis, and malignancy has become increasingly appreciated as the function of platelets in the pathophysiology of these processes has been defined. This review will consider the formation, release, and physiologic roles of alpha-granules with special emphasis on work performed over the last decade.

Prognostic significance of a pretreatment hematologic profile in patients with head and neck cancer

BACKGROUND

The purpose of this retrospective study was to test whether the pretreatment hematologic profile can predict the prognosis of patients with head and neck cancer.

METHODS

Medical records from 278 patients with head and neck cancer were reviewed, and 270 cases were evaluable. Clinical data including age, gender, stage, pretreatment hematologic profile (including white blood cell, platelet, and differential counts, and hemoglobin level) were recorded. Statistical analyses were performed to determine the prognostic effect of these hematologic indicators, as well as clinical variables. The association between the hematologic indicators and clinical factors was also analyzed.

RESULTS

Pretreatment monocytes >1,000 cells/microl (P = 0.028), hemoglobin <11.0 g/dl (P = 0.022), and platelet count >400 x 10(3) cells/microl (P = 0.017) were identified as independent prognostic factors in addition to the nodal status and metastasis. A significant correlation between T-stage/monocyte or platelet count and metastasis/platelet count were shown. Monocytosis, anemia, and thrombocytosis were demonstrated to have a cumulative effect on the prognosis of head and neck cancer patients (normal vs. abnormality in one lineage, P = 0.001; abnormality in one vs. more than one lineage, P = 0.005).

CONCLUSIONS

A pretreatment hematologic profile can be considered as a useful prognostic marker in patients with head and neck cancer.