Quantitative analysis of tryptase and chymase containing mast cells in benign and malignant breast lesions

Tumor signaling to the bone marrow changes the phenotype of monocytes and pulmonary macrophages during urethane-induced primary lung tumorigenesis in A/J mice

Little is known about how the composition of stromal cells within the lung cancer microenvironment varies during tumor progression. We examined by immunohistochemistry each of six different stromal cell populations during the development of chemically induced primary lung cancer in mice. Blood vessels were seen even in microscopic lesions, and their numbers increased with tumor size. Neutrophils infiltrated the alveoli of tumor-bearing lungs and within the periphery of macroscopic adenomas and adenocarcinomas. The numbers of peritumoral lymphocytes and macrophages increased during oncogeny, but quantitative changes in mast cells and fibroblasts were not evident. Because macrophage depletion reduces tumor growth and these cells are thus important to tumorigenesis, we also investigated their phenotype. Pulmonary macrophages expressed arginase I (subtype M2) but not inducible nitric-oxide synthase in lungs with premalignant lesions, whereas macrophages in carcinoma-bearing lungs expressed inducible nitric-oxide synthase (subtype M1) but not arginase I. Local pulmonary stimuli did not seem responsible for this shift in macrophage activation state because monocytes still residing within the bone marrow adopted these expression patterns before entering the circulation, presumably in response to tumor-derived signals. These biochemical markers of macrophage activation states would have diagnostic and/or therapeutic value if analogous systemic shifts occur in humans.

Stromal mast cells in invasive breast cancer are a marker of favourable prognosis: a study of 4,444 cases

PURPOSE

We have previously demonstrated in a pilot study of 348 invasive breast cancers that mast cell (MC) infiltrates within primary breast cancers are associated with a good prognosis. Our aim was to verify this finding in a larger cohort of invasive breast cancer patients and examine the relationship between the presence of MCs and other clinical and pathological features.

EXPERIMENTAL DESIGN

Clinically annotated tissue microarrays (TMAs) containing 4,444 cases were constructed and stained with c-Kit (CD-117) using standard immunoperoxidase techniques to identify and quantify MCs. For statistical analysis, we applied a split-sample validation technique. Breast cancer specific survival was analyzed by Kaplan-Meier [KM] method and log rank test was used to compare survival curves.

RESULTS

Survival analysis by KM method showed that the presence of stromal MCs was a favourable prognostic factor in the training set (P = 0.001), and the validation set group (P = 0.006). X-tile plot generated to define the optimal number of MCs showed that the presence of any number of stromal MCs predicted good prognosis. Multivariate analysis showed that the MC effect in the training set (Hazard ratio [HR] = 0.804, 95% Confidence interval [CI], 0.653-0.991, P = 0.041) and validation set analysis (HR = 0.846, 95% CI, 0.683-1.049, P = 0.128) was independent of age, tumor grade, tumor size, lymph node, ER and Her2 status.

CONCLUSIONS

This study concludes that stromal MC infiltration in invasive breast cancer is an independent good prognostic marker and reiterates the critical role of local inflammatory responses in breast cancer progression.

Immunosurveillance function of human mast cell?

Mast cell (MC) is so widely recognized as a critical effector in allergic disorders that it can be difficult to think of MC in any other context. Indeed, MCs are multifunctional and recently shown that MCs can also act as antigen presenters as well as effector elements of human immune system. First observations of their possible role as anti-tumor cells in peri- or intra-tumoral tissue were mentioned five decades ago and a high content of MCs is considered as a favorable prognosis, consistent with this study. Believers of this hypothesis assumed them to be inhibitors of tumor development through their pro-apoptotic and -necrolytic granules e.g., granzymes and TNF-alpha. However, some still postulate them to be enhancers of tumor development through their effects on angiogenesis due to mostly tryptase. There are also some data suggesting increased MC density causes tumor development and indicates bad prognosis. Furthermore, since MC-associated mediators have shown to influence various aspects of tumor biology, the net effect of MCs on the development/progression of tumors has been difficult to evaluate. For instance, chymase induces apoptosis in targets; yet, tryptase, another MC protease, is a well-known mitogen. MCs with these various enzyme expression patterns may mediate different functions and the predominant MC type in tissues may be determined by the environmental needs. The coexistence of tryptase-expressing MCs (MC(T)) and chymase and tryptase-expressing MCs (MC(TC)) in physiological conditions reflects a naturally occurring balance that contributes to tissue homeostasis. We have recently discussed the role and relevance of MC serine proteases in different bone marrow diseases.

Mast cells and angiogenesis in canine melanomas: malignancy and clinicopathological factors

The biological significance of mast cells and angiogenesis in canine melanomas is unclear. Eighty canine melanomas (56 malignant and 24 benign), investigated to determine the relationship between mast cell count (MCC), microvessel density (MVD) and clinicopathology, revealed significantly higher MCC and MVD counts in malignant melanomas. Evaluation of the prognostic significance of MCC and MVD in malignant melanomas showed a significant correlation between MCC and MVD both within and at the edges of the tumour. Multivariate analysis indicated that MCC and MVD were independent predictors of survival but the former was a significantly better prognostic marker. Greater numbers of mast cells and microvessels were found in malignant melanomas of poor prognosis. The findings demonstrate a prognostic significance of MCC and MVD in canine melanocytic tumours.

Neovascularization and mast cells with tryptase activity increase simultaneously with pathologic progression in human endometrial cancer

OBJECTIVE

In vitro and in vivo studies have linked mast cell (MC) degranulation and activation with angiogenesis and neovascularization. This assumption is partially supported by the close anatomic association between MC and the vasculature and the recruitment of these cells during tumor growth. The aim of this study was to correlate the extent of angiogenesis with the number of MC expressing tryptase in human endometrial adenocarcinoma.

STUDY DESIGN

Tissues from human endometrial hyperplasia and endometrial adenocarcinoma were investigated immunohistochemically, using 2 murine monoclonal antibodies against the endothelial cell marker CD31 and the MC marker tryptase.

RESULTS

Angiogenesis, measured as microvessel counts, was highly correlated with MC tryptase-positive cell counts and that these parameters increase in agreement with tumor progression.

CONCLUSION

These results suggest that angiogenesis in endometrial cancer increases with tumor progression and that angiogenic tryptase secreted by host MC cooperate in its induction.

Degranulating mast cells in fibrotic regions of human tumors and evidence that mast cell heparin interferes with the growth of tumor cells through a mechanism involving fibroblasts

BACKGROUND

The purpose of this study was to test the hypothesis that mast cells that are present in fibrotic regions of cancer can suppress the growth of tumor cells through an indirect mechanism involving peri-tumoral fibroblasts.

METHODS

We first immunostained a wide variety of human cancers for the presence of degranulated mast cells. In a subsequent series of controlled in vitro experiments, we then co-cultured UACC-812 human breast cancer cells with normal fibroblasts in the presence or absence of different combinations and doses of mast cell tryptase, mast cell heparin, a lysate of the human mast cell line HMC-1, and fibroblast growth factor-7 (FGF-7), a powerful, heparin-binding growth factor for breast epithelial cells.

RESULTS

Degranulating mast cells were localized predominantly in the fibrous tissue of every case of breast cancer, head and neck cancer, lung cancer, ovarian cancer, non-Hodgkin's lymphoma, and Hodgkin's disease that we examined. Mast cell tryptase and HMC-1 lysate had no significant effect on the clonogenic growth of cancer cells co-cultured with fibroblasts. By contrast, mast cell heparin at multiple doses significantly reduced the size and number of colonies of tumor cells co-cultured with fibroblasts, especially in the presence of FGF-7. Neither heparin nor FGF-7, individually or in combination, produced any significant effect on the clonogenic growth of breast cancer cells cultured without fibroblasts.

CONCLUSION

Degranulating mast cells are restricted to peri-tumoral fibrous tissue, and mast cell heparin is a powerful inhibitor of clonogenic growth of tumor cells co-cultured with fibroblasts. These results may help to explain the well-known ability of heparin to inhibit the growth of primary and metastatic tumors.

Application of novel tissue microarrays to investigate expression of tryptase, chymase and KIT protein in placental mast cells

INTRODUCTION

Tissue microarrays comprise numerous small representative tissue samples from hundreds of different cases assembled on a single histologic slide, and therefore allow high throughput analysis of multiple specimens at the same time. Mast cells are paracrine cells found ubiquitously in connective tissue. Expression of the serine proteases tryptase and chymase, as well as KIT protein, the receptor for stem cell factor (SCF), has been demonstrated in mast cells. Because little is known about the role of mast cells in the placenta, we investigated the number and expression of chymase, tryptase, and KIT protein in placental mast cells using newly developed tissue microarrays.

MATERIALS AND METHODS

Tissue microarrays were prepared from archival paraffin tissue blocks of 90 placentae, including 15 normal ones as a control group. Gestational age of the placentae ranged from 7 to 42 weeks. Sections of formalin-fixed paraffin-embedded material were prepared on chemically activated cover-slides. The slides were cut in 4-mm(2) squares containing representative areas, and transferred to a tissue microarray. Hematoxylin and eosin (H&E), chloroacetate esterase (CAE), toluidine blue, periodic acid--Schiff (PAS), and immunohistochemical staining were performed. The number of mast cells and expression of chymase, tryptase, and KIT protein were evaluated in each case.

RESULTS

Mast cell numbers in placentae with inflammation/abortion exceeded that of normal placentae. Although statistically not significant, we furthermore observed an increase in chymase-positive mast cells in the group of placentae associated with fetal malformations/chromosomal aberrations compared with normal placentae.

DISCUSSION

Novel tissue microarray technique has been introduced into placental research, and allows multiple placental tissue samples to be effectively analyzed simultaneously. This study indicated an increased number of chymase-positive mast cells in placentae with fetal malformation/chromosomal aberration. Activation of angiotensin II by chymase may play a role in fetal malformation. Moreover, it has been speculated that mast cells may only express chymase (MC(C)). Our findings denote the presence of placental MC(C). However, further studies are needed to elucidate more precisely the role of mast cell chymase in the placenta.

Mast cell numbers and protease expression patterns in biopsy specimens following renal transplantation from living-related donors predict long-term graft function

In human kidney transplantation the main cause of declining long-term graft function is chronic allograft nephropathy (CAN). Recent studies have implicated human mast cells (MC) in chronic inflammation and fibrosis, MC can be subtyped according to protease content: MC(T) containing tryptase only and MC(TC) containing both tryptase and chymase. We investigated immunohistochemically whether numbers and subtypes of MC in biopsy specimens 100 d after transplantation could predict subsequent fibrosis and graft dysfunction. The total number of MC/high-power field at 100 d after transplantation correlated significantly with change in creatinine clearance (DeltaCcr), defined as (Ccr at 100 d) - (Ccr at 3 yr) (R = 0.597, p = 0.0021); fibrosis index (FI) at 100 d (R = 0.583, p = 0.0066); and DeltaFI, defined as (FI at 3 yr) - (FI at 100 d) (R = 0.406, p < 0.05). The ratio of MC(TC) to total MC at 100 d also correlated with DeltaCcr (R = 0.491, p = 0.0148), FI at 100 d (R = 0.527, p = 0.0081), and DeltaFI (R = 0.417, p < 0.05). Thus, increases in number of total MC and the ratio of MC(TC) to total MC in early biopsy specimens were related to decline of long-term graft function and fibrosis.

Characterization of mast cell subpopulations in lip cancer

BACKGROUND

Lip squamous cell carcinoma (SCC) is the most common form of oral cancer. Human mast cells (MCs), which are increased in lip SCC, are classified by their protease content in tryptase-positive (MC(T)) and tryptase/chymase-positive (MC(TC)). MC proteases are associated with tumor progression and angiogenesis. The aim of this study was to quantify and characterize MC subpopulations in lip SCC.

METHODS

Serial sections from lip SCC (n = 21) and normal lip vermilion (n = 8) biopsies were stained immunohistochemically for tryptase and enzymehistochemically for chymase to determine MC subpopulation density and distribution.

RESULTS

MC(T) and MC(TC) were increased in lip SCC when compared with normal lip (P < 0.0001), where MC(T) predominated over MC(TC) (P < 0.01). In lip SCC neither subpopulation predominated. Regarding distribution, MC(T) were higher than MC(TC) at the intratumoral stroma, whereas MC(TC) were higher than MC(T) at the peritumoral stroma (P < 0.01).

CONCLUSIONS

The results suggest that MC subpopulations may contribute to lip SCC progression. While intratumoral MC(T) may stimulate angiogenesis, peritumoral MC(TC) may promote extracellular matrix degradation and tumor progression at the invasion front.

Decreased susceptibility of mast cell-deficient Kit(W)/Kit(W-v) mice to the development of 1, 2-dimethylhydrazine-induced intestinal tumors

Administration of 1,2-dimethylhydrazine (DMH) induces intestinal epithelial tumors in mice. Increased numbers of mast cells have been reported to occur both within and near a variety of different neoplasms, including DMH-induced intestinal tumors. We investigated the role of the tyrosine kinase receptor, c-kit, and mast cells, in this model by administering DMH to c-kit mutant mast cell-deficient mice and the congenic normal mice. We attempted to induce colonic tumors by administering DMH (20 mg/kg body weight, s.c., weekly for 20 weeks) to WBB6F1-Kit+/+ (+/+) wild-type mice, the congenic mast cell-deficient WBB6F1-Kit(W)/Kit(W-v) (W/W(v)) mice and W/W(v) mice that had been repaired of their mast cell deficiency by adoptive transfer of bone marrow cells derived from the congenic +/+ mice. The susceptibility to the development of DMH-induced colonic tumors, and the numbers of mast cells associated with these tumors, was evaluated. Normal (+/+) mice exhibited significantly higher numbers of mast cells in DMH-induced intestinal tumors than in macroscopically normal colonic mucosa. Treatment with DMH induced development of colonic tumors in 97% of +/+ mice, but in only 32% of the W/W(v) mice. W/W(v) mice that had been repaired of their mast cell deficiency by transfer of +/+ bone marrow cells expressed susceptibility to the development of colonic tumors that was similar to that of wild-type mice. These results show that genetic impairment of c-kit function reduces the susceptibility of mice to DMH-induced colonic tumors, and that defects in bone marrow-derived cells in the W/W(v) mice contribute significantly to this result. Our findings also are consistent with the possibility that mast cells promote the development of DMH-induced colonic epithelial tumors in mice.

Quantitative analysis of mast cells in benign and malignant breast lesions. Immunohistochemical study on formalin-fixed, paraffin-embedded tissues

BACKGROUND

It has been reported that the number of mast cells was significantly greater in malignant breast carcinomas than in benign breast lesions. This was due to tryptase-containing mast cells while tryptase, chymase-containing mast cells had no effect. However, analysis of mast cells in breast carcinomas and benign breast lesions based on their histological findings remains to be elucidated.

METHODS

Using immunohistochemical methods morphological examinations of mast cells were undertaken in benign and malignant breast tissues from 51 patients (30 benign, 21 malignant), which were formalin-fixed and paraffin-embedded. In the study with malignant breast tissues, samples of malignant tissues and adjacent healthy tissues were obtained from a single patient, and the number of mast cells was compared.

RESULTS

Among benign breast tissues, the number of mast cells in intracanalicular fibroadenoma was significantly lower than that in pericanalicular fibroadenoma as well as that in mastopathy. The number of mast cells was significantly greater in malignant lesions than that in benign lesions. The number of mast cells in scirrhous carcinoma and that in solid-tubular carcinoma were significantly increased compared with that in adjacent healthy tissues. In addition, the number of mast cells in scirrhous carcinoma was highest among breast carcinomas, and significantly greater than that in papillotubular carcinoma.

CONCLUSION

We were the first to find the significant lower number of mast cells in intracanalicular breast fibroadenoma when compared with that in pericanalicular fibroadenoma as well as that in mastopathy. Moreover, the number of mast cells in scirrhous carcinoma was significantly greater than that in papillotubular carcinoma.

Role of infiltrated leucocytes in tumour growth and spread

Leucocytes are a major component of the tumour microenvironment. Recent studies have indicated that the infiltration and activity of these host cells are regulated by the tumour to promote its survival and progression. Through the production of an array of growth factors, proteases and angiogenic mediators, leucocytes in the tumour microenvironment promote tumour growth, angiogenesis and metastasis.

Mast cell inhibitor cromolyn increases blood clotting and hypoxia in murine breast cancer

Human breast cancer is extensively infiltrated by mast cells that contain powerful anticoagulants such as heparin, tryptase and chymase. To determine if human breast cancer is associated with mast cell activation, we measured the levels of mast cell tryptase (an indicator of mast cell activation) in the blood of 20 women with varying stages of breast cancer. The mean level of tryptase in women with breast cancer (10.3 +/- 4.2 microg/L) was significantly higher than in 50 normal healthy women without breast cancer (3.0 +/- 2.5 microg/L, p < 0.05 by two-tailed t-test). To explore the role of mast cells in breast cancer in more detail, we then carried out experiments that were aimed at determining if an inhibitor of mast cell function, sodium cromolyn, could increase blood clotting and hypoxia within subcutaneous implants of the 4T1 mammary adenocarcinoma cell line in mice. We treated tumor-bearing mice with 5 consecutive daily doses of sodium cromolyn (10 mg/kg, i.p.). An average of 30% of the periphery of the tumors from the 5 drug-treated mice contained large lakes of clotted blood that were not evident in any of the tumors from the control (untreated) mice. By computerized image analysis of tumors immunostained for a hypoxia marker (pimonidazole), the tumors from the treated mice had significantly more hypoxia (35 +/-12 % hypoxic regions, n = 5) than the tumors from untreated (control) mice (16 +/- 7%, n = 5). We conclude that sodium cromolyn enhanced peri-tumoral blood clotting and intratumoral hypoxia. These results suggest that mast cells may play an important role in regulating blood clotting and hypoxia within breast cancer.

Acceleration of tumor growth and peri-tumoral blood clotting by imatinib mesylate (Gleevec)

Imatinib mesylate (Gleevec) inhibits the BCR-ABL tyrosine kinase in chronic granulocytic leukemia. Previous studies have demonstrated that imatinib mesylate also inhibits the survival and functions of normal mast cells by interfering with the receptor tyrosine kinase for stem cell factor (SCF), c-kit, which is expressed by mast cells. Because mast cells extensively surround many types of cancer and contain powerful anticoagulants such as heparin, we investigated the effects of imatinib mesylate on blood clotting and tumor growth within subcutaneous implants of a mammary adenocarcinoma cell line (4T1) in BALB/c mice. After 5 days of oral treatment with 10 mg/kg of the drug, the average mass of the tumors in treated mice (198 +/- 42 mg, n = 5) was significantly (p < 0.05) greater than the average mass of the tumors from untreated (control) mice (60 +/- 23 mg, n = 5). Moreover, the tumors in the treated mice were frequently surrounded by large lakes of clotted blood that were not evident in tumors from the control mice. Accelerated growth and blood clotting were also observed in tumor-bearing mice treated with heparinase I enzyme to destroy endogenous mast cell heparin and in NDST-2 knockout mice in which there is a targeted disruption in the gene coding for mast cell heparin synthesis. We conclude that imatinib mesylate accelerated the growth and peri-tumoral blood clotting of implants of mammary adenocarcinoma in mice. These results suggest that imatinib mesylate may have significant effects on mast cells infiltrating tumors, in addition to its other biologic activities. Our results also indicate that the mechanism of this effect may be related to the anticoagulant properties of mast cell heparin.

Mast cells and human hepatocellular carcinoma

AIM: To investigate the density of mast cells (MCs) in human hepatocellular carcinoma (HCC), and to determine whether the MCs density has any correlations with histopathological grading, staging or some baseline patient characteristics.

METHODS: Tissue sections of 22 primary HCCs were histochemically stained with toluidine blue, in order to be able to quantify the MCs in and around the neoplasm using a computer-assisted image analysis system. HCC was staged and graded by two independent pathologists. To identify the sinusoidal capillarisation of each specimen 3 μm thick sections were histochemically stained with sirius red, and semi-quantitatively evaluated by two independent observers. The data were statistically analysed using Spearman's correlation and Student's t-test when appropriate.

RESULTS: MCs density did not correlate with the age or sex of the patients, the serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels, or the stage or grade of the HCC. No significant differences were found between the MCs density of the patients with and without hepatitis C virus infection, but they were significantly higher in the specimens showing marked sinusoidal capillarisation.

CONCLUSION: The lack of any significant correlation between MCs density and the stage or grade of the neoplastic lesions suggests that there is no causal relationship between MCs recruitment and HCC. However, as capillarisation proceeds concurrently with arterial blood supply during hepatocarcinogenesis, MCs may be considered of primary importance in the transition from sinusoidal to capillary-type endothelial cells and the HCC growth.

Increase of mast cells and tumor angiogenesis in oral squamous cell carcinoma

BACKGROUND

Although mast cells (MCs) have been implicated in promoting angiogenesis in some malignant tumors, especially of the aerodigestive tract, little is known in oral squamous cell carcinoma (SCC).

METHODS

A retrospective study was conducted to elaborate upon the correlation between MCs and tumor angiogenesis in 26 cases of oral SCC, six cases of oral pre-malignant dysplasia, 10 cases of oral hyperkeratosis, and six cases of normal oral mucosa by means of immunohistochemical technique.

RESULTS

The MCs in all lesions and normal oral mucosa strongly expressed tryptase. The densities of MCs and microvessels appeared to increase with disease progression. The MC and microvascular counts were significantly higher in oral SCC than in hyperkeratosis and normal oral mucosa (P < 0.05). A significant correlation between MC and microvascular densities was observed in oral SCC (r = 0.5; P = 0.012).

CONCLUSIONS

These findings suggest that MCs may upregulate tumor angiogenesis in oral SCC, perhaps via MC tryptase.

Chymase expressing bone marrow mast cells in mastocytosis and myelodysplastic syndromes: an immunohistochemical and morphometric study

BACKGROUND

Two cell specific neutral proteases, tryptase and chymase, are produced by human mast cells (MC). Tryptase is constitutively expressed by all MC, whereas chymase is found only in an MC subset. Very little is known about chymase expression in MC proliferative disorders (mastocytosis).

AIMS AND METHODS

Routinely processed, formalin fixed, and paraffin wax embedded bone marrow trephine biopsy specimens obtained from patients with various subtypes of mastocytosis (n = 47) and myelodysplastic syndromes (MDS; n = 28) were immunostained with antibodies against chymase and tryptase. Normal/reactive bone marrow specimens with intact haemopoiesis (n = 31) served as controls. The numbers of chymase expressing (C+) and of tryptase expressing (T+) MC were assessed morphometrically using a computer assisted video camera system.

RESULTS

In normal/reactive bone marrow, the numbers of C+ MC (median, 8/mm(2); maximum, 159/mm(2)) were in the same range as those of T+ MC (median, 4/mm(2); maximum, 167/mm(2)). Because normal MC express both chymase and tryptase, these findings indicate that the common phenotype of bone marrow MC in normal/reactive states is MC(TC) (MC expressing both tryptase and chymase). In contrast, in MDS and mastocytosis, the bone marrow exhibited far more T+ MC than C+ MC in almost all cases.

CONCLUSIONS

According to these findings, the predominant MC type in the bone marrow in neoplastic states such as MDS and mastocytosis is MC(T) (MC expressing only tryptase). Although the pathophysiological basis of this apparent lack of chymase expression in most neoplastic MC in mastocytosis and MC involved in MDS remains unknown, this study has produced further evidence of the superior value of antitryptase antibodies in the diagnosis of mastocytosis.

Tumor angiogenesis of non-small cell lung cancer

Lung cancer is one of the commonest causes of cancer death in developed countries. Recent evidence suggests that angoigenesis is related to poor prognosis in many solid tumors including non-small cell lung cancer (NSCLC). Angiogenesis is regulated by a complex interaction among growth factors and cytokines and influenced by proteolytic enzymes such as plasminogen activators and matrix metalloproteases, expression of adhesion molecules, and distribution of extracellular matrices. Fibroblasts, macrophages, mast cells, and endothelial cells themselves also affect angiogenesis. This review concentrates on angiogenic growth factors including vascular endothelial growth factor, angiopoietins, platelet derived endothelial growth factor, and basic fibroblast growth factor, proteases, adhesion molecules including vascular endothelial cadherin and integrins, osteopontin, and mast cell products in tumor angiogenesis of NSCLC.

Expression of cyclooxygenase-2 (COX-2) in tumour and stroma compartments in cervical cancer: clinical implications

This study aims at investigating the relationship between cyclooxygenase-2 expression in tumour vs stroma inflammatory compartment and its possible clinical role. The study included 99 stage IB-IV cervical cancer patients: immunostaining of tumour tissue sections was performed with rabbit antiserum against cyclooxygenase-2. CD3, CD4, CD8, CD25, Mast Cell Tryptase monoclonal antibodies were used to characterise stroma inflammatory cells in nine cervical tumours. An inverse relation was found between cyclooxygenase-2 levels (cyclooxygenase-2 IDV) of tumour vs stroma compartment (r=-0.44, P<0.0001). The percentage of cases showing high tumour/stromal cyclooxygenase-2 IDV ratio was significantly higher in patients who did not respond to treatment (93.3%) with respect to patients with partial (60.5%), and complete (43.7%) response (P= 0.009). Cases with a high tumour/stroma cyclooxygenase-2 IDV ratio had a shorter overall survival rate than cases with a low tumour/stroma cyclooxygenase-2 IDV (P<0.0001). In the multivariate analysis advanced stage and the status of tumour/stroma cyclooxygenase-2 IDV ratio retained an independent negative prognostic role. The proportion of CD3(+), CD4(+), and CD25(+) cells was significantly lower in tumours with high tumour/stroma cyclooxygenase-2 IDV ratio, while a higher percentage of mast cells was detected in tumours showing high tumour/stroma cyclooxygenase-2 IDV ratio. Our study showed the usefulness of assessing cyclooxygenase-2 status both in tumour and stroma compartment in order to identify cervical cancer patients endowed with a very poor chance of response to neoadjuvant therapy and unfavourable prognosis.

Mast cells and angiogenesis

Angiogenesis is tightly regulated by pro- and anti-angiogenic factors. Secreting mast cells are able to induce and enhance angiogenesis via multiple in part interacting pathways. They include mast cell-derived (i) potent pro-angiogenic factors such as VEGF, bFGF, TGF-beta, TNF-alpha and IL-8, (ii) proteinases and heparin, that release heparin-binding pro-angiogenic factors lodged on cell surfaces and in the extracellular matrix (ECM), (iii) histamine, VEGF, and certain lipid-derived mediators that induce microvascular hyperpermeability having pro-angiogenic effects, (iv) chemotactic recruitment of monocytes/macrophages and lymphocytes that are able to contribute with angiogenesis-modulating molecules, (v) activation of platelets that release pro-angiogenic factors, (vi) activation of neighboring stationary non-mast cells, which secrete pro-angiogenic factors, ECM-degrading proteinases and stem cell factor which attracts, mitogenically stimulates and activates mast cells, (vii) auto- and paracrine stimulation of mast cells by stem cell factor, (viii) recruitment of mast cells by pro-angiogenic factors such as VEGF, bFGF and TGF-beta. As a result of ECM-degradation and changes in the microenvironment following initial mast cell secretion, the mast cell populations may change significantly in number, phenotype and function. In tumor models, mast cells have been shown to play a decisive role in inducing the angiogenic switch which precedes malignant transformation. There is, moreover, strong evidence that mast cells significantly influence angiogenesis and thus growth and progression in human cancers.

Activation of mast cells within a tumor of angiosarcoma: ultrastructural study of five cases

The accumulation of mast cells around tumors is a well-recognized phenomenon in a number of malignancies, including basal cell carcinoma, melanoma, and breast cancer. However, little information exists regarding mast cells within tumor nests. To clarify the role of mast cells infiltrating in skin cancers, we examined the morphological features of mast cells within tumors of five cases of angiosarcoma, including two patients with Stewart-Treves syndrome, by electron microscopy. In light microscopy, mast cells were observed within tumor nests at various densities and exhibited weak staining intensity with toluidine blue. By electron microscopy, most of the tumor-infiltrating mast cells exhibited anaphylactic or piecemeal degranulation, indicating that the mast cells had been activated in situ. Some mast cells were noted in close apposition to tumor cells, suggesting the existence of direct cell-to-cell interactions. Tumor cells adjacent to mast cells showed no degenerative changes. In conclusion, these results suggest that careful histologic examination in combination with electron microscopy should enable us to identify more mast cells within cancer lesions with greater sensitivity than in a number of prior reports. Furthermore, the close proximity of mast cells and surrounding tumor cells suggests some biologically significant role of mast cells in the development of angiosarcoma, including tumor growth as well as host immunity and stromal reaction.

Assessment of protamine-induced thrombosis of tumor vessels for cancer therapy using dynamic contrast-enhanced MRI

Since the role of angiogenesis in cancer development has been recognized, the study of anti-angiogenic or anti-vascular therapeutic agents has become increasingly important for cancer treatment. Selective thrombosis is one approach towards this goal. Since many types of carcinoma accumulate large numbers of degranulating mast cells which will release heparin, intravenously injected protamine may bind to heparin, neutralize its anti-coagulant effect and induce thrombosis. In this work we studied the formation of thrombosis by using dynamic contrast enhanced MRI. The enhancement kinetics of the contrast medium measured before and after protamine treatment were compared to assess the thrombotic effect. The underlying concept was that if the vessels became clotted, the subsequently injected contrast medium could not be delivered into the tissue to cause enhancement. In addition to the tissue-specific changes, protamine may also induce systemic effect in the host. The therapy-induced changes measured in tumors were compared to changes in normal tissues: liver, kidney, and especially the muscle adjacent to tumor. The results showed that protamine induced pronounced changes in the tumor. However, the degree of change measured by MRI was not associated with the results of semiquantitative assessment of thrombosis assessed by histology, perhaps due to the heterogeneous nature of the tumor and the difficulty in sampling sufficient regions histologically. The protamine-induced temporal effects were also studied. We demonstrated that protamine could induce selective thrombosis in tumors, and that the effect could last for several hours. Dynamic contrast-enhanced MRI can serve as a suitable means to investigate the mechanism of this novel approach to induce selective thrombosis for anti-vascular cancer therapy.

Characterization of mast cells according to their content of tryptase and chymase in normal and neoplastic human uterine cervix

Mast cells (MC) have been associated with diverse human cancers. The primary function of these cells is to store and release a number of biologically active mediators, including the serine proteases tryptase and chymase. These proteases have been closely related with angiogenesis and tumor invasion, two critical steps during tumor progression. In the present work we analyzed the presence of MC in human uterine cervix from both normal and neoplastic tissues by using metachromatic, immunohistochemical, and enzymohistochemical staining. Tryptase-positive (MCT)- and tryptase/chymase-positive (MCTC)-mast cells were found in both normal and neoplastic tissues. The phenotype predominantly expressed in normal tissues as well as in benign and malignant lesions of the uterine cervix was the MCT. The total number of MC remained constant through the different stages of malignant transformation (cervical intraepithelial neoplasia grade 1-3) but a significant increase in the invasive carcinoma (IC) group was observed, this increase being mainly due to the MCT phenotype. Furthermore, we detected abundant MCT but not MCTC infiltrating tumors in sections of IC. Regarding the potent angiogenic properties described for tryptase, these findings suggest that in advanced stages of malignancy the significant number of MCT distributed within the cervical tissues could provide an effective mechanism to create the abundantly vascularized microenvironment required for tumor cells to proliferate and disseminate.

The role of mast cell tryptase in neoangiogenesis of premalignant and malignant lesions of the uterine cervix

Recently, mast cell tryptase has been identified as another potent proangiogenic factor in tumors, along with fibroblast and vascular endothelial growth factors. Its role has been studied in a number of cancers, including carcinoma of the uterine cervix, with discordant results. Our aim was to study the expression of tryptase and bFGF in mast cells (MCs) during development of neoangiogenesis in premalignant and malignant lesions of the cervix. Biopsy specimens from 21 patients without cancer and from 63 patients with dysplasias and squamous cell carcinomas were used. They were stained with Alcian blue-safranin O (ABSO) and immunostained with specific antibodies against factor VIII, CD105, tryptase, and bFGF. Tryptase-positive mast cells increased with tumor progression and were close to newly formed blood vessels. Vascularization showed a linear increase from dysplasia to invasive cancer. We suggest that MC tryptase may upregulate neoangiogenesis in carcinogenesis of the uterine cervix.

Selective thrombosis of tumor blood vessels in mammary adenocarcinoma implants in rats

Adenocarcinomas in rats and humans frequently contain perivascular, degranulating mast cells that release heparin. Protamine is a low-molecular weight, cationic polypeptide that binds avidly to heparin and neutralizes its anticoagulant properties. We hypothesized that mast-cell heparin functions as a localized anticoagulant that modulates hemostasis and blood perfusion in tumors. Consequently, systemically administered protamine should be able to neutralize the endogenous heparin within tumors, thereby inducing selective thrombosis of blood vessels within tumors. Here we demonstrate with magnetic resonance imaging (MRI) that an intravenous dose of protamine labeled with gadolinium accumulated within the parenchyma of subcutaneous implants of a mammary adenocarcinoma in Fischer 344 rats. Moreover, we show with dynamic contrast enhanced MRI that sequential intravenous doses of protamine in 12 tumor-bearing rats resulted in significantly decreased signal enhancement kinetics (blood perfusion) of the tumor. This functional impairment of MRI signal enhancement was accompanied by histological evidence of thrombosis in the blood vessels within the tumor. There was no histological evidence of thrombosis within normal liver, kidney, lung, spleen, or adjacent muscle of tumor-bearing animals that received protamine treatment or in the tumors of animals that had not been pretreated with protamine. On the basis of these results, we conclude that protamine accumulates within adenocarcinoma implants and induces selective thrombosis of blood vessels within the tumor, probably by neutralizing the endogenous heparin within tumors.

Metaplastic transformation of urinary bladder epithelium: effect on mast cell recruitment, distribution, and phenotype expression

Mucosal mast cells (MCs) are normally found in the connective tissue stroma but are redistributed into the epithelium in conditions associated with immunoglobulin E responses, such as allergic inflammation and nematode infections, as well as in interstitial cystitis, a condition of unknown etiology. The potential role of epithelium-derived factors in this response prompted this inquiry into growth and differentiation signaling in normal tissue as well as in tissues from five different metaplastic conditions of the urothelium (cystitic cystica, cystitis glandularis, colonic metaplasia, squamous cell metaplasia, and nephrogenic metaplasia). Expression of the two major human MC growth factors, stem cell factor (or kit ligand) and interleukin 6, was detected using immunohistochemistry. In the case of interleukin 6, its mRNA expression was also detected using in situ reverse transcription-polymerase chain reaction. Among the different metaplastic lesions, nephrogenic metaplasia was the only one associated with an abundance of MCs, which were distributed within or in close relationship to the epithelium. Unlike in the other types of metaplasia, the epithelium strongly co-expressed interleukin 6 and stem cell factor. The MCs expressed the stem cell factor receptor CD117 and exhibited a variable tryptase immunoreactivity, but lacked chymase. They also displayed a relative deficiency of granular glycosaminoglycan, as indicated by a lack of metachromasia, and were sensitive to strong aldehyde fixation. The findings suggest that the MC response in nephrogenic metaplasia may be the result of local epithelial stem cell factor/interleukin 6 expression.