Serous and mucinous ovarian tumors express different profiles of MMP-2, -7, -9, MT1-MMP, and TIMP-1 and -2

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play key roles in tumorigenesis, but little is known of their expression according to mucinous or serous type. This study aimed to evaluate the immunohistochemical expression of MMP-2, -7, -9, MT1-MMP, TIMP-1 and -2 in these tumors. A tissue microarray was set up including 99 serous (25 benign, 27 borderline, 47 malignant) and 79 mucinous (25 benign, 44 borderline, 10 malignant) ovarian tumors. Immunostaining results were scored by using the HSCORE and assessed by univariate, unsupervised hierarchical clustering and multidimensional scaling analyses. Epithelial expression of MMP-2, -7, -9, MT1-MMP, TIMP-2, but not TIMP-1, was higher in serous than mucinous tumors. Stromal expression of MMP-7 was higher in serous tumors. Alterations in MT1-MMP, MMP-7 and -9 were found in malignant serous tumors, while benign and borderline tumors shared similar expressions. By unsupervised hierarchical clustering analysis, mucinous and serous tumors were better differentiated by epithelial than stromal MMP and TIMP immunolabelling. By multidimensional scaling analysis, the expressions of MMPs and TIMPs were scattered in serous tumors and homogeneous for mucinous tumors. In conclusion, our results support the differential expression in MMPs and TIMPs of ovarian tumors according to serous or mucinous histology.

Peritoneal fluids from patients with certain gynecologic tumor contain elevated levels of bioactive lysophospholipase D activity

Levels of lysophosphatidic acid (LPA), an important phospholipid mediator, in serum and ascitic fluid from ovarian cancer patients were shown to be higher than those from healthy women and from patients with other type of cancer, respectively. Although LPA in human serum seems mainly to be generated by lysophospholipase D (lysoPLD), the source and pathway for LPA in the ascitic fluid remain still obscure. In this study, we examined whether lysoPLD activity producing bioactive LPA in human peritoneal fluid was significantly elevated under pathological statuses. Lysophospholipase D activity in human peritoneal fluids was measured by quantifying choline released from exogenous lysophosphatidylcholine on their incubation at 37 degrees C. We also compared the activity of lysoPLD in sera from patients with different gynecologic diseases. We found relatively high lysoPLD activity in peritoneal fluids from patients with ovarian cancer, dermoid cyst or mucinous cystadenoma, whereas there were no significant differences in the serum lysoPLD activity among clinical groups and healthy subjects. The lysoPLD in the peritoneal fluid was found to have similar substrate specificity and metal ion requirement to those of serum lysoPLD, that has been identified as autotaxin, a tumor cell-motility stimulating protein. Our results suggest that increased lysoPLD activity in peritoneal fluid from patients with certain gynecologic tumors might be relevant to its potential of tumor progression.

Expression of transmembrane carbonic anhydrases IX and XII in ovarian tumours

AIMS

Carbonic anhydrase (CA) isozymes IX and XII have been suggested to play a role in oncogenic processes. The aim of the present study was to investigate CA IX and XII expression in patients with ovarian tumours.

METHODS AND RESULTS

A series of ovarian tumours was immunostained for CA IX and XII and the results were correlated with histopathological and clinical parameters. Most cases of borderline mucinous cystadenomas, mucinous cystadenocarcinomas and serous cystadenocarcinomas were moderately or strongly positive for CA IX. In malignant tumours, the staining was most prominent in hypoxic regions. Expression of CA XII was detected in all tumour categories, although the mean staining intensity was weaker than for CA IX in all groups except for clear cell carcinomas.

CONCLUSIONS

The wide expression of CA IX and XII in ovarian tumours suggests that these isozymes could represent potential targets in ovarian cancer therapy. The expression pattern of CA IX suggests that it could also serve as a useful histopathological marker protein for hypoxia in malignant ovarian tumours.

COX-2 expression in pseudomyxoma peritonei

COX-2 expression was studied using an immunohistochemical method in 75 patients with pseudomyxoma peritonei (PMP). Twenty-five patients presented with disseminated peritoneal adenomucinosis (DPAM) and 50 with peritoneal mucinous carcinomatosis (PMCA). COX-2 was expressed in neoplastic mucinous epithelium of 30 cases (40%): 20 in PMCA (40%), 10 in DPAM (40%). Weak COX-2 expression was also noted in four of five patients with appendiceal mucinous neoplasms without peritoneal dissemination. In addition, COX-2 was detected in stromal, endothelial, inflammatory cells and reactive mesothelium. This preliminary information indicates a potential for the use of COX-2 inhibitors in patients with PMP.

[Expression of topoisomerase III alpha in epithelial ovarian tumors of different types and relation between the expression of topoisomerase III alpha and the clinical pathology of tumor]

OBJECTIVE

To investigate the expression status of topoisomerase IIIa in epithelial ovarian tumor and the relationship between the expression status of topoisomerase IIIa and pathological type and clinical stage of epithelial ovarian carcinoma.

METHODS

Immunohistochemistry was carried out in the samples of ovarian tumor obtained during operation from 169 patients, aged 28 approximately 59, 18 cases with serous cystadenoma, 30 cases with serous borderline cystadenoma, 37 serous cystadenocarcinoma, 10 cases with mucous cystadenoma, 20 mucous borderline cystadenoma, 26 mucous cystadenocarcinoma, 19 cases with endometrial carcinoma of ovary, and 9 cases with clear cell carcinoma.

RESULTS

The expression rate of topoisomerase IIIa was 17.9% in the benign ovarian tumors, 74.0% in the borderline cystadenoma, and 42.7% in the malignant tumors with statistical significance among them (chi(2) = 24.657, P < 0.001). There was no correlation between the expression of topoisomerase IIIa and the clinical stage or pathological grade of the tumors (P = 0.903 and P = 0.844).

CONCLUSION

Topoisomerase IIIa is highly expressed in epithelial ovarian carcinoma, and its expression level is correlated with the character and type of tumor tissues.

Telomerase gene expression in intraductal papillary-mucinous tumors (IPMT): preliminary findings

BACKGROUND AND AIM

The surgical management of IPMT is based upon a preoperative suspicion of malignancy, that is difficult to obtain from the available diagnostic tools.

METHODS

Telomerase gene expression was investigated by means of hTERT/RT-PCR on total RNA from peripheral blood, tumour and non-tumour pancreatic samples of 2 patients with IPMT.

RESULTS

Histological diagnosis was mild-grade dysplasia in the first case and invasive carcinoma in the second. Telomerase expression was undetectable in all the samples derived from the first case. Blood and tumour samples from the second patient were positive for telomerase mRNA expression, while the pancreatic non-tumour specimen was not.

CONCLUSIONS

The following suggestions are made: 1) the telomerase gene expression seems to be implicated in the malignant evolution of IMPT; 2) the malignant transformation may be limited to a single area of the gland; 3) the presence of invasive carcinoma may be preoperatively suspected by peripheral venous blood sample collection. A possible clinical employment of telomerase gene expression determination in the management of IPMT is thus hypothesized.

u-PA expression in benign, borderline and malignant ovarian tumors

The malignant potential of solid tumors is related to their ability to invade adjacent tissue and to metastasize. The plasminogen activation system is one of the critical factors in tumor progression since it is involved in tumor invasion and metastasis. This study was performed to examine the expression of u-PA in benign, borderline and malignant tumors of the ovary by immunohistochemical evaluation on formalin-fixed, paraffin-embedded specimens applying monoclonal antibody 3689 directed to the b-chain of u-PA. Normal epithelial cells of the ovary (n = 5) showed no staining of u-PA but some stromal cells were slightly stained. Invasive carcinomas (n = 16) and borderline tumors (n = 15) showed a moderate to strong diffuse cytoplasmic staining. Benign tumors (n = 20) showed a variety of staining. The observation of randomly positive u-PA stromal cells is noteworthy. The percentage of u-PA-positive tumors was higher in carcinomas than in other tumors. There was no correlation with other known risk factors of malignancy such as differentiation, stage or type of tumor. In conclusion there are noticeable differences in u-PA expression among ovarian tumors and u-PA increase in ovarian tumors can be attributed to an increased diffuse cytoplasmic content in the neoplastic epithelial cells.

Expression of matrix metalloproteinases and related tissue inhibitors in the cyst fluids of ovarian mucinous neoplasms

OBJECTIVES AND METHODS

The growth of an ovarian cystic neoplasm often involves its invasion into and destruction of the extracellular matrix. We examined neoplastic cysts of ovarian mucinous tumors for the presence of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) using zymography (in situ zymography, gelatin zymography, and casein zymography) and enzyme-linked immunosorbent assay.

RESULTS

Matriolytic activity was detected within the cystic contents and cytoplasm of the lining epithelial cells of the cyst by in situ zymography. This intracystic matriolytic activity was thought to originate mainly in the epithelial cells. The activated form of MMP-9 was seen in all carcinoma and borderline fluids and in 7 of 15 adenomas. The concentration of MMP-9 was higher in carcinoma fluids than in borderline and adenoma fluids (P < 0.05). TIMP-1, which specifically binds to MMP-9, was also higher in carcinoma and borderline fluids than in adenoma fluids (P < 0.05). MMP-2 activity was nearly ubiquitously present in all cyst fluids, irrespective of the fluid's histologic category. The amount of MMP-2 was highest in the carcinoma category, although not to a statistically significant degree. TIMP-2, a specific inhibitor for MMP-2, was significantly lower in the borderline category than in the adenoma category. The molar ratios of TIMP-1/MMP-9 (not significant) and TIMP-2/MMP-2 (P < 0.05) were higher in the adenoma category. Expressions of trypsin, MMP-7, and MMP-9 were generally higher in carcinoma and borderline fluids than in adenoma fluids.

CONCLUSIONS

These observations indicate the importance of ovarian cystic fluids for analyzing tumor-associated matriolytic activities. The findings suggest that these matriolytic enzymes, together with the presence of their inhibitors, play an important role in the growth of ovarian mucinous tumors.

Immunohistochemical localization of beta-1,4-galactosyltransferase in human pancreatic tissues

beta-1,4-Galactosyltransferase (GalTase) is the glycosyltransferase in the Golgi apparatus that transfers galactose from UDP-galactose to terminal N-acetylglucosamine residues in glycoconjugates with formation of a beta-1,4 linkage. Neoplasms undergo various changes in the carbohydrate moieties of their glycoconjugates. This process also indicates the possibility of changes in glycosyltransferases themselves. Therefore, we compared the binding pattern of a monoclonal antibody (MAb8628) against GalTase in both normal and neoplastic exocrine pancreatic tissues. Ten normal and 11 neoplastic human exocrine pancreatic tissues obtained from surgery were used. Frozen sections were incubated with this antibody. Supranuclear regions and terminal bars of normal duct cells and acinar cells revealed positive staining for GalTase at the light microscopic level. Centroacinar cells revealed positive staining in their perinuclear region. Neoplastic cells were also stained in their supranuclear regions and terminal bars. Supranuclear regions were well developed in neoplastic cells and intensely stained compared with those in normal cells. The supranuclear regions and the terminal bars corresponded to the trans cisternae of the Golgi apparatus and the junctional complex (i.e., tight junction and adherens junction), respectively, seen at the electron microscopic level. Pancreatic neoplastic changes thus led to an increase in the expression of GalTase in the Golgi apparatus, the increase of which may have an important effect on the intercellular adhesion and communication among pancreatic epithelial cells. Measurement of this enzyme is useful for diagnosis of exocrine pancreatic neoplastic changes from normal tissues.

Overexpression of H-Ryk in mouse fibroblasts confers transforming ability in vitro and in vivo: correlation with up-regulation in epithelial ovarian cancer

Abnormalities in the function of receptor tyrosine kinases (RTKs) have been demonstrated to be important in the pathogenesis of cancer. H-Ryk, a new member of the RTK family, is an unusual RTK in that it is catalytically inactive because of amino acid substitutions of conserved residues in the catalytic domain. We show by immunohistochemistry that it is expressed in the epithelium, stroma, and blood vessels of normal tissues. Evaluation of a panel of 33 primary ovarian tumors (2 benign, 8 borderline, and 23 malignant) was performed. H-Ryk was overexpressed in borderline and malignant ovarian tumors. In serous and clear cell subtypes, there was increased expression in the epithelium, stroma, and blood vessels. Consistent with this observation, overexpression of H-Ryk in the mouse fibroblast cell line NIH3T3 induces anchorage-independent growth and tumorigenicity in nude mice. This implies that overexpression of the receptor can be transforming and may therefore be significant in the pathogenesis of ovarian cancer.

Histopathologic and immunohistochemical study of steroidogenic cells in the stroma of ovarian tumors

The presence of steroidogenic or enzymatically active stromal cells in ovarian tumors can lead to various endocrine manifestations by the overproduction of sex steroids. We studied the clinicopathologic and immunohistochemical features of histologically identified steroid-type cells or enzymatically active cells in the stroma of ovarian lesions. Among 1,249 ovarian tumors or tumorlike lesions, steroid cells were histologically identified in the stroma in 32 ovarian neoplasms, of which 29 were mucinous cystadenomas. The cells were Leydig- or hilus-type cells in 4 of the tumors and were lutein-type cells in the remaining 28. None of the 32 tumors were immuno-reactive for human chorionic gonadotropin or luteinizing hormone. Lutein-like steroid cells were intermingled with spindle-shaped stromal cells and capillaries, while Leydig-type cells were more often associated with dilated vessels. The transcription factor of steroidogenesis, adrenal 4-binding protein (Ad4BP), was present in nearly all steroid-type stromal cells. However, steroidogenic enzymes, 17 alpha-hydroxylase (C17) and 3 beta-hydroxysteroid dehydrogenase (3 beta SD), were expressed only in 10 of 15 cases of histologically identified steroid cells. Steroid cells in which Ad4BP but not C17 or 3 beta HSD were expressed were all lutein-type. Aromatase was rarely detected in lutein-and Leydig-type cells. The presence of morphologically identified steroid cells does not necessarily indicate expression within these cells of steroidogenic enzymes, a finding that merits further attention.