Ovarian Surface Epithelial Carcinomas Research Articles

Regulation of gene expression in ovarian cancer cells by luteinizing hormone receptor expression and activation

BackgroundSince a substantial percentage of ovarian cancers express gonadotropin receptors and are responsive to the relatively high concentrations of pituitary gonadotropins during the postmenopausal years, it has been suggested that receptor activation may contribute to the etiology and/or progression of the neoplasm. The goal of the present study was to develop a cell model to determine the impact of luteinizing hormone (LH) receptor (LHR) expression and LH-mediated LHR activation on gene expression and thus obtain insights into the mechanism of gonadotropin action on ovarian surface epithelial (OSE) carcinoma cells.MethodsThe human ovarian cancer cell line, SKOV-3, was stably transfected to express functional LHR and incubated with LH for various periods of time (0-20 hours). Transcriptomic profiling was performed on these cells to identify LHR expression/activation-dependent changes in gene expression levels and pathways by microarray and qRT-PCR analyses.ResultsThrough comparative analysis on the LHR-transfected SKOV-3 cells exposed to LH, we observed the differential expression of 1,783 genes in response to LH treatment, among which five significant families were enriched, including those of growth factors, translation regulators, transporters, G-protein coupled receptors, and ligand-dependent nuclear receptors. The most highly induced early and intermediate responses were found to occupy a network impacting transcriptional regulation, cell growth, apoptosis, and multiple signaling transductions, giving indications of LH-induced apoptosis and cell growth inhibition through the significant changes in, for example, tumor necrosis factor, Jun and many others, supportive of the observed cell growth reduction in in vitro assays. However, other observations, e.g. the substantial up-regulation of the genes encoding the endothelin-1 subtype A receptor, stromal cell-derived factor 1, and insulin-like growth factor II, all of which are potential therapeutic targets, may reflect a positive mediation of ovarian cancer growth.ConclusionOverall, the present study elucidates the extensive transcriptomic changes of ovarian cancer cells in response to LH receptor activation, which provides a comprehensive and objective assessment for determining new cancer therapies and potential serum markers, of which over 100 are suggested.

Frequency and distribution of HER2 overexpression in advanced malignancies.

e21153 Background: Testing for HER2 has revolutionized the management of breast cancer and, now, gastro-esophageal junction cancer. The purpose of this study was to capture the relative frequency and distribution of HER2 overexpression in other cancers. Methods: In a cohort of 11,223 patient samples, HER2 was assayed by immunohistochemistry using the Ventana HER2 (4B5) antibody. Slides were then read by pathologists using the cutoff of (>=3+ and >=30% as positive) for HER2. In this same cohort, 2,246 patient samples underwent HER2 by FISH testing using Abbott’s Pathvysion HER2 assay. FISH analysis was interpreted by a cytogeneticist based on ASCO/CAP guidelines for breast cancer. Prior to the analysis, 4,116 patient samples were excluded secondary to an unknown tumor lineage or other lineage rarely seen in our laboratory. In all, twenty-seven tumor lineages comprising 7,107 patient specimens were analyzed. Results: Our preliminary observations indicated that the frequency of HER2 by IHC is highest in breast carcinoma (68.6%), colorectal adenocarcinoma (7.2%), ovarian surface epithelial carcinoma (5.4%), gastroesophageal adenocarcinoma (4.5%), non-small cell lung cancer (3.1 %), pancreatic adenocarcinoma (1.3%) and gastric adenocarcinoma (1.3%) In these same lineages, frequency of HER2 by FISH is highest in breast carcinoma (46.0%) followed by surface epithelial ovarian carcinoma (12.7%), non-small cell lung cancer (8.3 %), gastroesophageal adenocarcinoma (6.7%), gastric adenocarcinoma (4.8%), pancreatic adenocarcinoma (4.0%), colorectal adenocarcinoma (3.2%). Distributional differences in IHC versus FISH results were analyzed by Pearson’s chi-square (x2) test, with statistical significance (p<0.05) achieved in breast carcinoma, gastric adenocarcinoma, gastroesophageal adenocarcinoma and surface epithelial ovarian carcinoma. Conclusions: To our knowledge, this is the first study involving a large patient pool with advanced malignancies in which HER2 status was investigated in a single clinical laboratory with standardized IHC and FISH. This study shows that HER2 is frequently expressed in other cancer types, which merits the inclusion of therapeutic strategies using HER2-targeted therapy in such tumors.

Immunohistochemical analysis of 17β-hydroxysteroid dehydrogenase isozymes in human ovarian surface epithelium and epithelial ovarian carcinoma

Epidemiological studies have indicated a relationship between gonadal steroid hormones, primarily estrogens, and epithelial ovarian carcinoma. In situ estrogen metabolism and synthesis have been considered to play important roles in the development of the progression of epithelial ovarian carcinoma. 17β-Hydroxysteroid dehydrogenases (17β-HSDs) are a group of intracellular isozymes catalyzing interconversions between estradiol (E2) and estrone (E1). In the last step of steroidogenesis, 17β-HSD type 1 catalyzes the 17β-reduction and produces E2 from E1. The oxidative enzymes known as types 2, 4, and 8 are potent estrogen-inactivating enzymes that convert E2 to E1. Here we report the immunoexpression of 17β-HSD types 1, 2, 4, and 8 in normal human ovarian surface epithelium (OSE) and epithelial ovarian carcinoma. For this study, novel polyclonal antibodies were generated against each type of 17β-HSD. Of the six normal OSE cases investigated, 17β-HSD types 1, 4, and 8, but not type 2, were found in the cytoplasm of epithelial cells. In 58 cases of epithelial ovarian carcinoma (45 serous, 4 endometrioid, 4 mucinous, and 5 clear cell), estrogen-inactivating 17β-HSDs were commonly found (type 2, 84.5%; type 4, 82.8%; type 8, 86.2%), whereas type 1 was detected in only 10 cases (17.2%). These results indicate that 17β-HSDs may be involved in the protective and/or suppressive effects against the estrogen-dependent proliferation of epithelial ovarian carcinoma.

Enhancing the Therapeutic Effect Against Ovarian Cancer Through a Combination of Viral Oncolysis and Antigen-specific Immunotherapy

Cancer therapy using oncolytic viruses represents a promising new approach for controlling ovarian cancer. In this study, we have circumvented the limitation of repeated vaccination by employing different virus vectors, Semliki Forest Virus (SFV) and vaccinia virus (VV) for boosting the immune response. We found that infection of tumor-bearing mice with VV followed by infection with SFV or vice versa leads to enhanced antitumor effects against murine ovarian surface epithelial carcinoma (MOSEC) tumors. Furthermore, infection with VV-ovalbumin (OVA) followed by infection with SFV-OVA or vice versa was found to lead to enhanced OVA-specific CD8(+) T-cell immune responses. In addition, we found that infection with SFV-OVA followed by infection with VV-OVA leads to enhanced antitumor effects in vivo and enhanced tumor killing in vitro through a combination of viral oncolysis and antigen-specific immunity. The clinical implications of this study are discussed.

Ovarian carcinoma pathology and genetics: recent advances

In this review we summarize recent advances in the histopathological diagnostic criteria and molecular pathology of the main subtypes of ovarian surface epithelial carcinoma. These advances have greatly improved our understanding of the biology of ovarian carcinoma and are also relevant to patient management. With progress toward subtype-specific treatment of ovarian carcinoma, accurate, reproducible histopathological diagnosis of these subtypes by practicing pathologists is increasingly important.

The expression of six biomarkers in the four most common ovarian cancers: correlation with clinicopathological parameters

This study aimed to evaluate the relationship of fascin-1, matrix metalloproteinase (MMP)-2, MMP-9, cortactin, survivin, and epidermal growth factor receptor (EGFR) expression with clinicopathological parameters for the four most common ovarian surface epithelial carcinomas. Six biomarkers were investigated immunohistochemically using tissue microarrays of 185 specimens including 79 serous cystadenocarcinomas, 47 mucinous cystadenocarcinomas, 45 endometrioid adenocarcinomas, and 14 clear cell carcinomas. The four most common ovarian carcinomas showed significant expression of fascin-1, cortactin, survivin, and EGFR, but not of MMP-2 and MMP-9. In addition, higher immunostaining scores for fascin-1 in mucinous cystadenocarcinomas correlated with T stage, N stage, American Joint Committee on Cancer AJCC clinical stage, and a poorer survival rate; for cortactin in serous cystadenocarcinomas correlated with T stage; for cortactin in clear cell carcinomas correlated with T and clinical AJCC stages; and for survivin in clear cell carcinomas correlated with T stage and AJCC clinical stage. In addition, higher immunostaining scores for fascin-1, cortactin, and survivin correlated with poorer tumor differentiation in serous, mucinous, and endometrioid adenocarcinomas. Thus, the expression of fascin-1, cortactin, and survivin may be helpful in evaluating the aggressiveness of ovarian mucinous, serous, and clear cell adenocarcinoma. Additionally, the expression of fascin-1 may be an independent prognostic risk factor in mucinous cystadenocarcinoma.

Loss of Integrin α3 Expression is Associated with Acquisition of Invasive Potential by Ovarian Clear Cell Adenocarcinoma Cells.

Among various types of surface epithelial ovarian carcinoma, clear cell adenocarcinoma often has a particularly poor prognosis even when diagnosed in stage I. It is resistant to existing anticancer drugs and appears to have different biological properties to other histological types of ovarian cancer. The present study was conducted using cell lines derived from ovarian clear cell adenocarcinoma in order to identify genes associated with the acquisition of malignant potential by this type of cancer. Two cell lines derived from ovarian clear cell adenocarcinoma (RMG-I and RMG-V), with different levels of invasive potential in an invasion assay, were used. DNA fragments were extracted from the band showing differences in the level of expression by RT-PCR with fluorescent differential display. A total of 56 different DNA base sequences were determined by direct sequencing. Primers were established using these base sequences and the level of expression in each cancer cell line was determined by real-time PCR. Integrin a3, the gene of which is present on chromosome 17q, was identified. It was also detected by a microarray analysis as one of the molecules showing a different level of expression between the two cell lines. Then the pattern of integrin a3 expression was investigated using immunocytochemical staining, and was found to differ between the two cell lines. The findings obtained using these cell lines derived from ovarian clear cell adenocarcinoma indicate that integrin alpha3 may associated with the acquisition of malignant potential by clear cell adenocarcinoma.

Tumor cell type can be reproducibly diagnosed and is of independent prognostic significance in patients with maximally debulked ovarian carcinoma

Ovarian surface epithelial carcinomas are routinely subclassified by pathologists based on tumor cell type and grade. It is controversial whether cell type or grade is superior in predicting patient response to treatment or survival, in patients stratified by stage of disease. The aim of this study was to uniformly apply updated criteria for cell-type and grade assignment to a series of 575 cases of ovarian surface epithelial carcinoma. All patients were optimally surgically debulked, with no macroscopic residual disease after primary surgery. Slides from these cases were reviewed by a single pathologist, who was blinded to patient outcomes. In 50 cases, 2 additional pathologists reviewed the slides independently to determine interobserver variation in assessment of cell type and grade. The distribution of tumor stage was as follows: stage I--233 cases, stage II--246 cases, stage III--96 cases. The most common cell type encountered was serous carcinoma (229/575, 40%), followed by clear cell (149/575, 26%), endometrioid (139/575, 24%), and mucinous (36/575, 6%). Serous carcinomas were significantly more likely to present with advanced stage disease (76/229 [33.2%] were stage III, and 82% of all stage III tumors were serous), whereas all nonserous cell types were stage I or II at diagnosis in greater than 90% of cases. Both FIGO grade and Silverberg grade stratified patients into groups with significantly different risks of relapse and survival, but the Silverberg grading system was a more powerful prognosticator. In multivariate analysis, stage was the most powerful prognostic indicator (P < .0001), followed by tumor cell type (P = .015), but grade was not of independent significance. Interobserver variation in assignment of cell type was very good (kappa = 0.77) with moderate reproducibility in assignment of Silverberg grade (kappa = 0.40) and minimal reproducibility in assignment of FIGO grade (kappa = 0.27). Thus, in this series of cases of ovarian surface epithelial carcinomas with no macroscopic residual disease after primary debulking surgery, assignment of tumor cell type was both more reproducible and provided superior prognostic information compared with assignment of tumor grade. As tumor cell type also correlates with underlying molecular abnormalities and may predict response to chemotherapy, this suggests that tumor cell type could be used to guide treatment decisions for patients with ovarian surface epithelial carcinoma.

Microsatellite Instability and Mismatch Repair Protein Defects in Ovarian Epithelial Neoplasms in Patients 50 Years of Age and Younger

Ovarian malignancies occurring in the setting of hereditary nonpolyposis colorectal carcinoma syndrome typically present in young women, often as the first or "sentinel" cancer, but the frequency of microsatellite instability (MSI) and mismatch repair (MMR) defects in ovarian surface epithelial malignancies in women <or=50 years of age is neither well known nor well tested. Fifty-two ovarian surface epithelial carcinomas, including 4 with synchronous endometrial carcinomas, were identified in patients 50 years of age or younger and evaluated for evidence of MSI and MMR protein deficiency. Each case was tested for MSI by multiplex polymerase chain reaction amplification of the National Cancer Institute reference panel (BAT25, BAT26, D2S123, D5S346, and D17S250) and deficiency of MMR protein expression by immunohistochemistry (MLH1, MSH2, MSH6, and PMS2). MMR protein expression and MSI (in a subset of cases) were also evaluated in 50 unselected ovarian serous tumors of low malignant potential , a tumor common in younger women. Defects in MMR were detected in 5 of 52 (10%) ovarian carcinomas by at least 1 testing method, including 2 of 4 (50%) ovarian cancers presenting with synchronous endometrial cancer. Three of the 5 (60%) ovarian carcinomas were clear cell carcinomas (17% of all pure clear cell carcinomas) and the remaining 2 were high-grade carcinomas with endometrioid and mixed histology. Loss of MSH2 and MSH6 was detected in all of the affected clear cell carcinomas and a synchronous endometrial cancer with endometrioid histology. Loss of 1 or more MMR proteins was initially noted in 10/50 ovarian serous tumors of low malignant potential on tissue microarray, but further testing on full tissue sections showed intact protein expression and microsatellite stability in all informative cases. This study demonstrates a 10% rate of MMR-deficient ovarian cancer in women <or=50 years of age. MMR-deficient ovarian cancer is frequently associated with loss of expression of MSH2 and MSH6 proteins and clear cell histology. The occurrence of MMR inactivation in a significant proportion of ovarian clear cell carcinomas (17% in this study) suggests that this tumor may warrant targeted testing in women <or=50 years of age.

GATA-4 and GATA-6 Expression in Human Ovarian Surface Epithelial Carcinoma

GATA-4 and GATA-6 are zinc finger transcription factors named for their recognition motif and involved in ovarian development and function. GATA factors are strongly expressed and primarily localized within the nuclei of ovarian surface epithelial cells. GATA factors have been previously shown to be expressed in sex-cord stromal ovarian tumors and may contribute to the tumor phenotype. Differential expression of GATA-4 within serous and mucinous ovarian carcinomas has been reported. Using immunohistochemistry, we studied GATA-4 and GATA-6 expression in 50 ovarian surface epithelial carcinomas and examined the relationship to clinicopathologic parameters and outcome. We found that the majority of the carcinomas retained GATA-4 expression, whereas approximately two-thirds of the carcinomas had mislocalization or loss of GATA-6 expression. No statistically significant correlations were found between histologic type, histologic grade, or patient outcome and GATA-4. Cytoplasmic GATA-6 expression tended to correlate with overall survival (P=0.0756). These findings suggest that although GATA factors play a role in ovarian surface epithelial carcinoma oncogenesis, they do not seem to affect clinicopathologic parameters.

Regulation of the BRCA1 promoter in ovarian surface epithelial cells and ovarian carcinoma cells

As BRCA1 expression is often suppressed in sporadic ovarian carcinoma we characterized the regulation of the 231nt proximal ‘L6’ fragment of the BRCA1 promoter in two human ovarian surface epithelial cell and two sporadic ovarian carcinoma cell lines. Two individual regulatory elements within L6, the ‘RIBS’ element and the potential ‘CRE’ element were each necessary, but alone not sufficient for L6 activation in all four cell lines. The latter element showed some affinity for the CREB transcription factor, but cAMP pathway stimulation failed to promote its activation. This element did, however, interact with, and was activated by, c-Jun and Fra2 which suggests that it can interact with AP1-like transcription factors and that it may act co-operatively with RIBS-binding factors to regulate BRCA1 transcription in ovarian cells.

Nonphotochemical Hole-Burning Study of Selectively Stained Normal and Cancerous Human Ovarian Tissues

Results are presented of nonphotochemical hole-burning (HB) experiments on cancerous ovarian and analogous normal peritoneal in vitro tissues stained with the mitochondrial-selective dye rhodamine 800. A comparison of fluorescence excitation spectra, hole-growth kinetics data, and external electric field (Stark) effects on the shape of spectral holes burned in cancerous and normal tissues stained with rhodamine 800 revealed significant differences only in the dipole moment change (fDeltamu) measured by a combination of HB and Stark spectroscopies. It is shown that the permanent dipole moment change for the S0--> S1 transition of the rhodamine 800 molecules in cancerous tissue is higher than that of normal tissue by a factor of about 1.4. The finding is similar to the HB results obtained earlier for human ovarian surface epithelial cell lines, i.e., OV167 carcinoma and OSE(tsT)-14 normal cells stained with the same mitochondria-specific dye (Walsh et al. Biophys. J. 2003, 84, 1299). We propose that the observed difference in the permanent dipole moment change in cancerous ovarian tissue is related to a modification in mitochondrial membrane potential.

Expression of cyclooxygenase-2 and inducible nitric oxide synthase in ovarian surface epithelial carcinomas: is there any correlation with angiogenesis or clinicopathologic parameters?

Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) products have been implicated in the regulation of immune system, tumor cell apoptosis, and angiogenesis in many human tumors. In this study, we investigated the expression of COX-2 and iNOS in ovarian carcinomas by immunohistochemistry and correlated the results with other prognostic parameters. Specimens from 100 ovarian carcinomas were studied by immunohistochemistry for COX-2 and iNOS expression, and angiogenesis microvessel density (MVD) was evaluated by CD34-stained microvessels. High COX-2 expression was observed in 85% of carcinomas. No correlation was found between COX-2 expression and clinicopathologic variables. Patients with high COX-2–expressed tumors had shorter overall survival, but it is not statistically significant. Expression of iNOS in serous and low-grade carcinomas was significantly higher than that in nonserous and high-grade carcinomas (P&lt; 0.05). There was a positive correlation between COX-2 and iNOS expression (P= 0.009). No correlation of COX-2 and iNOS expression with MVD was found. Expression of iNOS showed no effect on survival of the patients. We found that iNOS expression might act in the first steps of carcinogenesis, whereas COX-2 expression was seen in more advanced tumors. Shorter overall survival of patients with high COX-2 expression might indicate new targets for therapy.

Expression of cyclooxygenase-2 and inducible nitric oxide synthase in ovarian surface epithelial carcinomas: is there any correlation with angiogenesis or clinicopathologic parameters?

Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) products have been implicated in the regulation of immune system, tumor cell apoptosis, and angiogenesis in many human tumors. In this study, we investigated the expression of COX-2 and iNOS in ovarian carcinomas by immunohistochemistry and correlated the results with other prognostic parameters. Specimens from 100 ovarian carcinomas were studied by immunohistochemistry for COX-2 and iNOS expression, and angiogenesis microvessel density (MVD) was evaluated by CD34-stained microvessels. High COX-2 expression was observed in 85% of carcinomas. No correlation was found between COX-2 expression and clinicopathologic variables. Patients with high COX-2-expressed tumors had shorter overall survival, but it is not statistically significant. Expression of iNOS in serous and low-grade carcinomas was significantly higher than that in nonserous and high-grade carcinomas (P < 0.05). There was a positive correlation between COX-2 and iNOS expression (P= 0.009). No correlation of COX-2 and iNOS expression with MVD was found. Expression of iNOS showed no effect on survival of the patients. We found that iNOS expression might act in the first steps of carcinogenesis, whereas COX-2 expression was seen in more advanced tumors. Shorter overall survival of patients with high COX-2 expression might indicate new targets for therapy.

Amplification of EMSY, a novel oncogene on 11q13, in high grade ovarian surface epithelial carcinomas

Objectives. Amplification of the 11q13 locus is commonly observed in a number of human cancers including both breast and ovarian cancer. Cyclin D1 and EMS1 have been implicated as candidate oncogenes involved in the emergence of amplification at this locus. Detailed analysis of the 11q13 amplicon in breast cancer led to the discovery of four regions of amplification suggesting the involvement of other genes. Here, we investigate the role of EMSY, a recently described BRCA2 interacting protein, as a key element of the 11q13 amplicon in ovarian cancer. EMSY maps to 11q13.5 and is amplified in 13% of breast and 17% of ovarian carcinomas. Methods. EMSY amplification was assessed by fluorescent in-situ hybridization (FISH) in 674 ovarian cancers in a tissue microarray and correlated with histopathological subtype and tumor grade. A detailed map of the 11q13 amplicon in 51 cases of ovarian cancer was obtained using cDNA-array-based comparative genomic hybridization (aCGH). To further characterize the role of EMSY within this amplicon, we evaluated both the amplification profiles and RNA expression levels of EMSY and two other genes from the 11q13 amplicon in an additional series of 22 ovarian carcinomas. Results. EMSY amplification was seen in 52/285 (18%) high grade papillary serous carcinomas, 4/27 (15%) high grade endometrioid carcinomas, 3/38 (8%) clear cell carcinomas, and 3/10 (30%) undifferentiated carcinomas. aCGH mapping of 11q13 in ovarian cancer showed that EMSY localized to the region with the highest frequency of copy number gain. Cyclin D1 and EMS1 showed a lower frequency of copy number gain. A highly significant correlation between EMSY gene amplification and RNA expression was also observed ( P = 0.0001). This was a stronger correlation than for other genes at 11q13 including Cyclin D1 and PAK1. Conclusions. These findings support the role of EMSY as a key oncogene within the 11q13 amplicon in ovarian cancer.

Assessment of Her-1, Her-2, and Her-3 Expression and Her-2 Amplification in Advanced Stage Ovarian Carcinoma

The human epidermal growth factor receptor (Her) family of receptor tyrosine kinases includes Her-1, Her-2, and Her-3. The overexpression of Her-1 and Her-2 have been reported previously in surface epithelial ovarian cancer. Although up to one-third of ovarian carcinomas have been found to have amplification or overexpression of Her-2, responses to trastuzumab therapy in these patients have been disappointing. In this study, we examined Her-1, Her-2, and Her- 3 protein expression as well as the frequency of Her-2 amplification in a series of 103 high-grade, advanced-stage (FIGO stage III or IV) ovarian surface epithelial carcinomas. Immunohistochemical staining using commercially available antibodies against Her-1-3 and fluorescence in situ hybridization (FISH) using probes against Her-2 and chromosome 17 centromere (CEP) were performed on a tissue microarray containing cores of tumor from 103 surface epithelial carcinomas (85 serous, 6 mixed surface epithelial, 5 clear cell, 3 endometrioid, 3 undifferentiated, 1 mucinous). Nine of 99 (9.1%) tumors were positive for Her-1 expression and 5 of 102 (4.9%) tumors were positive for Her-2 expression, with 1 showing strong immunoreactivity. None of the Her-1 positive tumors exhibited Her-2 immunoreactivity. There was no correlation between Her-1 or Her-2 expression and survival. Using Her-2:centromere fluorescence ratios of 2.0 or 1.5 as cutoffs in assessment of Her-2 amplification, 8 of 75 (10.7%) and 25 of 75 (33.3%) tumors, respectively, showed Her-2 amplification. Two of eight tumors that showed higher level (>2) Her-2 amplification by FISH also were positive for Her-2 by immunohistochemistry. Only 3 of 103 tumors expressed Her-3. Immunoreactivity for Her-1 and Her-2 was less frequently observed in this series than has been previously reported. The strong correlation between Her-2 immunostaining and amplification characteristic of breast carcinoma is not seen in ovarian carcinoma. These results indicated that few patients with ovarian carcinoma have tumors that would benefit from therapy targeted specifically against Her-1, Her-2, or Her-3.

Primary and metastatic mucinous adenocarcinomas in the ovaries: incidence in routine practice with a new approach to improve intraoperative diagnosis.

Mucinous carcinomas are reported to comprise 6-25% of ovarian carcinomas (mean 12%), but recent refinements in the interpretation of histologic features of noninvasive and metastatic mucinous carcinomas suggest that this may be an overestimate. Mucinous carcinomas in the ovaries are commonly metastatic, but the proportion of primary versus metastatic mucinous carcinomas in unselected patients is unknown. To evaluate the histologic-type distribution of ovarian surface epithelial carcinomas, a consecutive series of 124 ovarian carcinomas was reviewed using uniform current criteria. Microinvasive and intraepithelial carcinomas and carcinomas arising in germ cell and stromal tumors were excluded. To evaluate the proportions of primary and metastatic tumors among the mucinous carcinomas, 52 consecutive mucinous carcinomas from nonreferral patients were reviewed. Three of 124 primary ovarian carcinomas were pure mucinous carcinomas (2.4%). Among 52 cases of mucinous carcinomas in the ovaries, 40 (77%) were metastatic and 12 (23%) were primary. Among the 12 primary mucinous tumors, three were atypical proliferative mucinous tumors with microinvasion and nine were invasive mucinous carcinomas. Among the 40 metastatic mucinous tumors, 18 (45%) were from the gastrointestinal tract, 8 (20%) were pancreatic, 7 (18%) were gynecologic malignancies (5 cervical, 2 endometrial), 3 (8%) were from the breast, and 4 (10%) were of unknown primary site. A simple rule that classifies all bilateral mucinous carcinomas as metastatic, unilateral mucinous carcinomas <10 cm as metastatic, and unilateral mucinous carcinomas >or=10 cm as primary correctly classified 90% of the neoplasms. This algorithm for distinguishing primary and metastatic mucinous carcinomas in the ovary can be used at the time of intraoperative consultation to guide surgical management. After careful exclusion of noninvasive, microinvasive, and metastatic tumors, pure mucinous adenocarcinoma primary in the ovary appears to be substantially less common than previously reported.

Single-cell nonphotochemical hole burning of ovarian surface epithelial carcinoma and normal cells.

Persistent spectral nonphotochemical hole-burning (NPHB) spectroscopy has recently been applied to dye molecules in cells. The sensitivity of NPHB to the nanoenvironment of the probe is well established. It has been shown that NPHB applied to bulk suspensions of cultured human cells can distinguish between normal and cancer cells. Thus, NPHB has potential as a diagnostic cancer tool. For this reason, the methodology is referred to as hole-burning imaging, by analogy with MRI. The optical dephasing time (T(2)) of the dye in hole-burning image replaces the proton T(1) relaxation time in MRI. In addition to the T(2) mode of operation, there are four other modes including measurement of the spectral hole growth kinetics (HGK). Reported here is that the selectivity and sensitivity of NPHB operating in the HGK mode allow for distinction between normal and carcinoma cells at the single-cell level. The ovarian cell lines are ovarian surface epithelial cells with temperature-sensitive large T antigens (analogously normal) and ovarian surface epithelial carcinoma (OV167) cells. The mitochondrial specific dye used was rhodamine 800 (Molecular Probes). This carbocationic dye is highly specific for the outer and inner membranes of mitochondria. In line with the results for bulk suspensions of the two cell lines, the hole-burning efficiency for OV167 cells was found to be significantly higher than that for normal cells. Theoretical analysis of the HGK data leads to the conclusion that the degree of structural heterogeneity for the probe-host configurations in OV167 cells is lower than in the normal cells. Possible reasons for this are given.

Gap junctional intercellular communication and connexin43 expression in human ovarian surface epithelial cells and ovarian carcinomas in vivo and in vitro.

Gap junctional intercellular communication (GJIC) and the expression of gap junction proteins (connexins) are frequently decreased in neoplastic cells and have been increased by cAMP and retinoids. GJIC and connexin expression were investigated in early passage normal human ovarian surface epithelial (HOSE) cells, human ovarian adenocarcinoma cell lines (CaOV-3, NIH:OVCAR-3, SK-OV-3 and SW626) and surgical specimens of human serous cystadenocarcinomas. We hypothesized that GJIC and connexin expression would be decreased in neoplastic cells and would be increased by cAMP and retinoic acid. Cultured HOSE cells exhibited extensive fluorescent dye-coupling and connexin43 (Cx43) expression; other connexins were not detected. The ovarian adenocarcinoma cell lines had little dye-coupling or connexin expression. Deletions and rearrangements of the Cx43 gene were not detected by Southern blotting in the carcinoma lines. N6, 2'-O-dibutyryladenosine 3',5'-cyclic monophosphate and all-trans-retinoic acid inhibited cell proliferation, but did not enhance GJIC or Cx43 expression. Surface epithelial cells of benign ovaries expressed Cx43, but this expression was barely detectable in ovarian serous cystadenocarcinomas. Thus, normal HOSE cells had extensive GJIC and Cx43 expression whereas ovarian carcinoma cells had less and cAMP and retinoic acid did not change these, although both agents inhibited cell growth.

Altered expression of gamma-glutamyl transpeptidase in human tumors

Elevated levels of gamma-glutamyl transpeptidase (GGT) activity and intracellular glutathione in tumor cells have been correlated with resistance to several classes of chemotherapeutic drugs. In this study, the first comprehensive analysis of GGT expression in human malignant neoplasms, 451 tumors were immunostained with an antibody directed against a c-terminus peptide of the human GGT protein. Analysis of the immunostaining revealed that GGT was expressed in 22 of 44 lung carcinomas and 16 of 22 ovarian surface epithelial carcinomas, although normal pulmonary and ovarian epithelium are GGT-negative. The tumor samples were obtained from patients before the start of therapy; therefore, GGT was not induced by radiation or chemotherapy. There was no GGT expression in mesotheliomas, Hodgkin's disease, non-Hodgkin's lymphomas, melanomas, basal cell carcinomas, and most soft tissue sarcomas, all of which are derived from GGT-negative cells. Carcinomas arising from some GGT-positive epithelium retained their GGT-positive phenotype. These included renal cell carcinomas, hepatocellular and cholangiocarcinomas, and carcinomas of the prostate and thyroid whereas both pancreatic adenocarcinomas and infiltrating carcinomas of the breast showed a wide range of GGT expression. Further studies are underway to determine whether expression of GGT plays a role in the inherent resistance of some tumors to alkylating agents and other classes of chemotherapeutic drugs.