Oncogene expression in ovarian cancer: a pilot study of c-myc oncoprotein in serous papillary ovarian cancer

Expression of DKK1 in Endometrial Endometrioid Carcinoma and Its Correlation with Wnt/β-catenin Signalling Pathway

Objectives

Endometrial cancer is the most prevalent form of cancer affecting female reproductive organs. The most common histologic type, endometrioid carcinoma, accounts for 75-80% of all endometrial cancer cases. Studies on DKK1 expression profiles and their inhibitory role in the Wnt signalling pathway in the genesis and development of endometrial carcinoma are scarce. This study aimed to investigate DKK1 expression in endometrial carcinoma and its correlation with the Wnt/β-catenin pathway.

Methods

A total of 160 formalin-fixed paraffin-embedded samples were included in this study (50 cases of endometrial atypical hyperplasia, 50 cases of endometrioid endometrial carcinoma, 30 cases of proliferative endometrium and 30 cases of secretory endometrium). The expression patterns of DKK1, E-cadherin, β-catenin and c-Myc in endometrial atypical hyperplasia and carcinoma were investigated and compared with that of proliferative and secretory endometrium. Immunohistochemistry and analysis were performed from July 2018 to June 2020.

Results

A decreasing pattern of immunopositivity for DKK1, E-cadherin and β-catenin from proliferative/secretory endometrium to endometrial atypical hyperplasia and endometrioid carcinoma was found. Increasing c-Myc immunopositivity was noted from proliferative/secretory endometrium to endometrial atypical hyperplasia and endometrioid carcinoma. Moreover, decreasing DKK1 immunopositivity was well correlated with E-cadherin, β-catenin and c-Myc immunopositivity.

Conclusion

Decreasing DKK1 positivity from benign endometrium to endometrioid carcinoma suggests a negative regulatory function of DKK1 in endometrioid carcinoma. DKK1 is downregulated in the Wnt signalling pathway in endometrioid endometrial carcinoma. Therefore, DKK1 is promising as a biomarker for screening endometrioid carcinoma. Future studies should examine the reactivation of the DKK1 gene, which may be a valuable strategy for antagonising the Wnt signalling pathway.

c-MYC and Epithelial Ovarian Cancer

Ovarian cancer is the deadliest of gynecological malignancies with approximately 49% of women surviving 5 years after initial diagnosis. The standard of care for ovarian cancer consists of cytoreductive surgery followed by platinum-based combination chemotherapy. Unfortunately, despite initial response, platinum resistance remains a major clinical challenge. Therefore, the identification of effective biomarkers and therapeutic targets is crucial to guide therapy regimen, maximize clinical benefit, and improve patient outcome. Given the pivotal role of c-MYC deregulation in most tumor types, including ovarian cancer, assessment of c-MYC biological and clinical relevance is essential. Here, we briefly describe the frequency of c-MYC deregulation in ovarian cancer and the consequences of its targeting.

Origins based clinical and molecular complexities of epithelial ovarian cancer

Ovarian cancer is the most lethal of all common gynaecological malignancies in women worldwide. Ovarian cancer comprises of >15 distinct tumor types and subtypes characterized by histopathological features, environmental and genetic risk factors, precursor lesions and molecular events during oncogenesis. Recent studies on gene signature profiling of different subtypes of ovarian cancer have revealed significant genetic heterogeneity between and within each ovarian cancer histological subtype. Thus, an immense interest have shown towards a more personalized medicine for understanding the clinical and molecular complexities of four major types of epithelial ovarian cancer (serous, endometrioid, clear cell, and mucinous). As such, further in depth studies are needed for identification of molecular signalling network complexities associated with effective prognostication and targeted therapies to prevent or treat metastasis. Therefore, understanding the metastatic potential of primary ovarian cancer and therapeutic interventions against lethal ovarian cancer for the development of personalized therapies is very much indispensable. Consequently, in this review we have updated the key dysregulated genes of four major subtypes of epithelial carcinomas. We have also highlighted the recent advances and current challenges in unravelling the complexities of the origin of tumor as well as genetic heterogeneity of ovarian cancer.

A multicolour flow cytometric assay for c-MYC protein in B-cell lymphoma

AIM

Develop an objective assay to detect c-MYC protein expression using multiparametric flow cytometry (FCM) as an alternative to immunohistochemistry (IHC).

METHODS

57 patient samples and 11 cell line samples were evaluated. Cell suspensions were obtained and c-MYC staining was performed in combination with CD45 and CD19 and, in some samples, CD10. The percentage of c-MYC+ cells by FCM was correlated with the percentage determined by IHC. The relationship between c-MYC protein expression and the presence of a c-MYC gene rearrangement in aggressive and high-grade lymphomas was also assessed.

RESULTS

c-MYC expression by FCM and IHC demonstrated a high degree of correlation in a training set of 33 patient cases, r=0.92, 11 cell line samples, r=0.81 and in a validation set of 24 aggressive and high-grade B-cell lymphomas, r=0.85. c-MYC gene was rearranged by fluorescence in situ hybridisation in 6/9 samples with high c-MYC expression (>40%) by FCM and 6/14 by IHC.

CONCLUSIONS

We have developed a reliable multicolour FCM assay to detect c-MYC expression suitable for clinical laboratories that should be helpful to accurately quantify c-MYC expression in B-cell lymphomas.

Regulation of DNA damage repair and lipid uptake by CX3CR1 in epithelial ovarian carcinoma

Failure of currently used cytotoxic chemotherapy is one of the main reasons behind high mortality from metastatic high grade serous ovarian carcinoma. We found that high expression of a receptor for fractalkine (CX₃CR1) significantly correlated with shorter survival of patients with serous ovarian carcinoma treated with cytotoxic DNA damage chemotherapies, and reduction of CX₃CR1 expression resulted in sensitization to several DNA damaging modalities, including x-ray radiation and cisplatin. Here, we show that CX₃CR1 plays a role in double-strand DNA break response and repair by regulating expression of RAD50 by a MYC-dependent mechanism. We demonstrate that downregulation of CX₃CR1 alone and in a combination with irradiation affects peritoneal metastasis in an organ-specific manner; we show that CX₃CR1 regulates lipid uptake which could control omental metastasis. This study identifies CX₃CR1 as a novel potential target for sensitization of ovarian carcinoma to DNA damage therapies and reduction of peritoneal carcinomatosis.

Correlation Between the Clinical Parameters and Tissue Phenotype in Patients Affected by Deep-Infiltrating Endometriosis

The current study aimed to identify and validate an applicable immunohistochemistry panel including Ki-67, c-MYC, estrogen receptor-α (ER-α), and progesterone receptor isoforms A/B (PR-A/B) in correlation with clinicopathological parameters in patients affected by deep infiltrating endometriosis. Tissue microarrays were prepared from a cohort of 113 patients. Phenotypic profile of the panel molecules was evaluated in glands and stroma in parallel with microvessels and stroma density measurements. Principal component analysis was performed on 8 immunohistochemical variables, 2 histological variables, and 8 subgroups of clinical parameters. The immunohistochemical profiling showed consistent Ki-67 immunostaining in 17.9% of the samples and c-MYC in 83.1%, while intense ER-α immunoreactivity was detected in 84% of the samples and PR-A/B isoforms in 24.1% of them. The combination of clinical parameters and tissue phenotype allowed a stratification of endometriosis-affected patients. Such novel phenotypical and clinical correlation could be helpful in the future studies for a better stratification of the disease aiming at a personalized patient care.

Highly and moderately aggressive mouse ovarian cancer cell lines exhibit differential gene expression

Patients with advanced epithelial ovarian cancer often experience disease recurrence after standard therapies, a critical factor in determining their five-year survival rate. Recent reports indicated that long-term or short-term survival is associated with varied gene expression of cancer cells. Thus, identification of novel prognostic biomarkers should be considered. Since the mouse genome is similar to the human genome, we explored potential prognostic biomarkers using two groups of mouse ovarian cancer cell lines (group 1: IG-10, IG-10pw, and IG-10pw/agar; group 2: IG-10 clones 2, 3, and 11) which display highly and moderately aggressive phenotypes in vivo. Mice injected with these cell lines have different survival time and rates, capacities of tumor, and ascites formations, reflecting different prognostic potentials. Using an Affymetrix Mouse Genome 430 2.0 Array, a total of 181 genes were differentially expressed (P < 0.01) by at least twofold between two groups of the cell lines. Of the 181 genes, 109 and 72 genes were overexpressed in highly and moderately aggressive cell lines, respectively. Analysis of the 109 and 72 genes using Ingenuity Pathway Analysis (IPA) tool revealed two cancer-related gene networks. One was associated with the highly aggressive cell lines and affiliated with MYC gene, and another was associated with the moderately aggressive cell lines and affiliated with the androgen receptor (AR). Finally, the gene enrichment analysis indicated that the overexpressed 89 genes (out of 109 genes) in highly aggressive cell lines had a function annotation in the David database. The cancer-relevant significant gene ontology (GO) terms included Cell cycle, DNA metabolic process, and Programmed cell death. None of the genes from a set of the 72 genes overexpressed in the moderately aggressive cell lines had a function annotation in the David database. Our results suggested that the overexpressed MYC and 109 gene set represented highly aggressive ovarian cancer potential biomarkers while overexpressed AR and 72 gene set represented moderately aggressive ovarian cancer potential biomarkers. Based on our knowledge, the current study is first time to report the potential biomarkers relevant to different aggressive ovarian cancer. These potential biomarkers provide important information for investigating human ovarian cancer prognosis.

Diverse mechanisms for activation of Wnt signalling in the ovarian tumour microenvironment

Wnt signalling pathways have been shown to play key roles in both normal development and tumorigenesis. Progression of many human cancers is associated with defined mutations in Wnt pathway components that result in dysregulated β-catenin-mediated gene transcription. Although Wnt pathway mutations are rare in epithelial ovarian cancer (with the exception of the endometrioid histotype), accumulating evidence supports a role for Wnt signalling in ovarian tumorigenesis in the absence of genetic mutations. The present review summarizes evidence in support of activated Wnt signalling in ovarian tumours and discusses alternative mechanisms for Wnt pathway activation in the ovarian tumour microenvironment.

Immunohistochemical analysis of c-myc, c-jun and estrogen receptor in normal, hyperplastic and neoplastic endometrium

To evaluate the role of c-jun and c-myc proto-oncogenes in normal, hyperplastic and neoplastic endometrium in relation to estrogen receptor (ER) status and to investigate whether these genes can be related to other histopathological features of endometrial carcinoma, 32 endometrial carcinomas, 38 endometrial hyperplasias and 22 cyclic endometria (10 proliferative and 12 secretory) were evaluated histologically. Endometrial hyperplasia cases were classified as simple and complex hyperplasia without atypia, and atypical hyperplasia. Endometrial carcinoma cases were subtyped according to the International Society of Gynecological Pathologists. Modified FIGO system was used for both grading and staging. Immunohistochemical examination was performed using antibodies to ER-alpha, c-myc and c-jun with streptavidin-biotin-peroxidase technique. The mean percentage of ER-alpha positive cells changed cyclically during the menstrual cycle, and it was the highest (96%) and the lowest (31.6%) in proliferative and carcinomatous endometrium, respectively. There was a statistically significant difference between proliferative and secretory phases and proliferative and carcinomatous endometrium in relation to ER-alpha staining (p<0.05). There was also a statistically significant difference with respect to ERalpha reactivity between secretory phase and each hyperplastic group, as well as between the carcinoma group and each hyperplastic group (p<0.05). Although not significant, the mean percentage of c-myc expressing cells in the carcinoma group was higher (15.3%) than that of proliferative phase and hyperplastic groups. The mean percentage of c-jun positive cells in proliferative endometrium was slightly higher than in secretory endometrium, and it was the highest in atypical hyperplastic endometrium (28.3%), but there was no statistically significant difference between the groups. In carcinoma cases, a positive correlation was observed between c-jun positivity and tumor grade (p=0.027, r=0.3908), but such a correlation with c-myc was not found. A positive correlation was detected between ER-alpha and c-myc expression (p=0.038, r=0.3686). A progressive loss of ER seems to be correlated with increasing malignant transformation. C-myc expression might play a role in the development of endometrial carcinoma via ER. The association between c-jun and ER appears to be lost in endometrial carcinoma. The relationship between c-myc, c-jun and ER appears to be altered in endometrial carcinoma compared to that of menstrual endometrium.

Estrogens and epithelial ovarian cancer

OBJECTIVE

Molecular mechanisms involved in ovarian carcinogenesis are still unclear, but there is growing evidence that estrogens promote tumor progression in an epithelial ovarian cancer (EOC) subgroup.

METHODS

We reviewed current knowledge on the effects of estrogens in ovarian carcinogenesis and new potential research focuses concerning hormonal therapy of EOC.

RESULTS

Experimentally, estrogen stimulates the growth of ovarian tumor cell lines expressing estrogen receptors (ER). We and other authors have demonstrated differential expression of ERalpha or beta during ovarian carcinogenesis, with overexpression of ERalpha as compared to ERbeta in cancer. This differential expression in ER suggests that estrogen-induced proteins may act as ovarian tumor-promoting agents. Among these proteins, c-myc, fibulin-1, cathepsin-D, or several kallikreins may play a role, since high expression levels have been found in EOC. Consistently, recent prospective epidemiological studies have indicated that estrogen replacement therapy in postmenopausal women may increase ovarian cancer incidence and mortality.

CONCLUSION

Questions on the estrogen-sensitivity and potential benefits of new hormone therapies in an EOC subgroup should be readdressed in the light of recent experimental and clinical data.

Cell Proliferation in Ovarian Carcinoma: Superior Accuracy of S-Phase Fraction (SPF) by DNA Labeling Index versus Flow Cytometric SPF, Lack of Independent Prognostic Power for SPF and DNA Ploidy, and Limited Effect of SPF on Tumor Growth Rate

OBJECTIVES

The goal of this work was to test the hypotheses that S-phase fraction (SPF) by DNA labeling index (SPF-LI) would predict the course of the disease for ovarian/peritoneal carcinomas and that SPF-LI would correlate better with pathologic classification and outcome than SPF by DNA flow cytometry (SPF-F).

METHODS

Tritiated thymidine (1985-1988) and bromodeoxyuridine (1988-1999) DNA labeling (SPF-LI) was evaluated in vitro on 178 tumors. Cellular DNA and SPF-F were measured flow cytometrically. During this time, 90% of ovarian/peritoneal tumors accessioned in surgical pathology were studied.

RESULTS

Tumors of low malignant potential (LMP, "borderline") had low SPF-LI (median = 1.2%). High-grade invasive carcinomas of various types and carcinosarcomas all had high SPF-LI (medians = 11.2-23.4%). Serous low-grade invasive carcinomas (median = 1.05) resembled LMP tumors. SPF-LI of ovarian carcinomas other than LMP tumors increased slightly as FIGO stage increased (P = 0.07). Survival of patients with high-grade ovarian carcinomas was not predicted by SPF-LI or SPF-F, nor was DNA ploidy predictive. SPF-LI produced tighter distributions for various tumor types than did SPF-F. Neither SPF nor DNA ploidy contributed to prediction of outcome when tumor type and stage were included in multivariate models. We calculated the mean cell loss rate of high-grade carcinomas to be 94%.

CONCLUSIONS

LMP ovarian/peritoneal tumors have low proliferation rates in contrast to high-grade carcinomas. Proliferation correlated with tumor type and stage, but neither it nor DNA ploidy predicted survival independently. Proliferation rate is growth limiting only when low. At higher levels cell loss limits growth. SPF-LI measures proliferation more accurately than SPF-F; SPF-F is not sufficiently reliable for clinical use.

Multivariate analyses of DNA index, p62c-myc, and clinicopathological status of patients with ovarian cancer

AIM

To determine if either DNA index or p62c-myc is an independent prognostic variable in ovarian cancer.

METHODS

Multivariate and univariate analyses of the relation between DNA index, p62c-myc, FIGO stage, histological type, tumour grade, completeness of surgery, and patient survival in ovarian cancer were examined.

RESULTS

Multivariate analysis showed significant association of survival only with stage and grade. There was no relation between survival and DNA index.

CONCLUSIONS

DNA index is not an independent prognostic variable in ovarian cancer.

Value of glutathione S-transferase pi and the oncogene products c-Jun, c-Fos, c-H-Ras, and c-Myc as a prognostic indicator in endometrial carcinomas

OBJECTIVE

To examine the relationship between the expressions of glutathione S-transferase pi (GST-pi) and four oncogene products, c-Jun, c-Fos, c-H-Ras, and c-Myc, and clinicopathological prognostic factors and patients' prognosis in endometrial carcinomas, and to assess their prognostic value in endometrial carcinomas.

METHODS

Specimens of endometrial carcinoma obtained from 63 patients were investigated immunohistochemically using respective specific antibodies.

RESULTS

The overall positive rates in 63 carcinoma specimens were 34.9% for GST-pi, 44.4% for c-Jun, 34.9% for c-Fos, 47.6% for c-H-Ras, and 54.0% for c-Myc. Multivariate analysis revealed that GST-pi expression correlated independently with paraaortic lymph node (PAN) metastasis, and c-Jun expression was independently related to pelvic lymph node (PLN) and PAN metastasis. The prognosis of patients with a GST-pi-positive tumor was significantly poorer than that of those with a GST-pi-negative tumor (P < 0.05). The patients with c-Jun-positive tumor also had a significantly worse prognosis than those with c-Jun-negative tumor (P < 0.05). No significant relationship between the expressions of the remaining three oncogene products, c-Fos, c-H-Ras, and c-Myc, and the examined prognostic factors and clinical outcome was apparent.

CONCLUSION

These results suggest that the expressions of GST-pi and c-Jun may reflect the metastatic potential of endometrial carcinomas and that their expressions of endometrial carcinoma may be useful as a prognostic indicator for predictive testing.

Estrogen action in human ovarian cancer

Evidence is accumulating for a facilitative role for estrogen in ovarian cancer. Although response to antiestrogen therapy has been poor, there is a distinct subset of patients that respond. Strategies for treatment of ovarian cancer would be improved by identification of patients likely to respond to hormonal therapy. Cell culture models that are responsive or resistant to estrogen and antiestrogen may be of value in finding markers that predict responsiveness to hormonal therapy. Several model cell lines have been generated that express ER and proliferate in response to estrogen in vitro. Further studies are needed to better characterize the response of these ER positive cells lines to estrogen in vivo in mouse xenograft models. Expression of many of the same genes are regulated by estrogen in breast and in ovarian cancer cell lines. One exception may be the HER-2/neu oncogene product, which is down-regulated by estrogen in responsive breast carcinoma cells but not in two ovarian carcinoma cell lines. Initial analyses of several estrogen responsive and one resistant cell model suggests the potential value of progesterone receptor presence and low levels of HER-2/neu expression for predicting responsiveness to hormonal therapy. Additional cell models need to be investigated to determine the frequency with which these markers are associated with antiestrogen resistance.

Computerized image analysis and flow cytometric evaluation of ovarian borderline tumors: a study of 24 cases

DNA content evaluation in the study of ovarian borderline tumors has been shown to be a useful adjunct to histopathologic diagnosis. This study compares flow cytometry and computerized image analysis (CIA) in evaluating the DNA content of these lesions. Twenty-four cases of ovarian borderline tumors (15 serous, 9 mucinous) were studied utilizing formalin-fixed paraffin-embedded tissue. Flow cytometry of cell suspensions and CIA of cell suspensions and paraffin sections were compared in the evaluation of DNA content. Twenty-three tumors (96%) were diploid and only 1 (4%) was aneuploid. There was 100% correlation between flow cytometry and CIA of cell suspensions. Image analysis of Feulgen-stained paraffin sections was found to be unreliable when compared with the use of cell suspensions in the evaluation of DNA content. Clinical follow-up in 17 patients showed recurrent disease in two patients with diploid tumors and no evidence of disease in the patient with an aneuploid tumor. The reported rate of aneuploidy in borderline tumors varies depending on the diagnostic method employed in evaluating DNA content. This study shows good correlation between flow cytometry and image analysis of cell suspensions and supports the low rate of aneuploidy found in these lesions by other authors utilizing these methods. The majority of borderline ovarian tumors have been shown to have a diploid DNA content; however, the finding of aneuploidy in histologically classified borderline tumors warrants close clinical follow-up since aneuploidy in these tumors has been associated with an adverse prognosis.

Expression of c-erbB-2, c-myc, and c-ras oncoproteins, insulin-like growth factor receptor I, and epidermal growth factor receptor in ovarian carcinoma

AIMS

To assess whether the overexpression of five dominant oncogene encoded proteins is crucial to the pathogenesis of ovarian carcinoma and whether this provides any useful prognostic information.

METHODS

The expression of the insulin-like growth factor 1 receptor (ILGFR 1), epidermal growth factor receptor (EGFR), and the c-erbB-2, c-ras, and c-myc products was studied by multiparameter flow cytometry in 80 patients with epithelial ovarian cancer for whom long term follow up was available.

RESULTS

Overexpression of ILGFR 1, EGFR, c-erbB-2, c-ras and c-myc was found in, respectively, nine of 80 (11%), 10 of 80 (12%), 19 of 80 (24%), 16 of 80 (20%) and 28 of 80 (35%) ovarian carcinomas. The levels of expression of ILGFR 1, EGFR, c-erbB-2 and c-ras were significantly higher in the tumours of patients with recurrent or persistent disease after chemotherapy than in the tumours of patients at initial presentation (p < 0.02). Multivariate analysis showed that residual tumour (p < 0.001), FIGO stage (p = 0.002), EGFR overexpression (p = 0.030) and previous chemotherapy (p = 0.034) were independent variables for predicting survival.

CONCLUSIONS

Overexpression of these oncoproteins only occurs in a small proportion of ovarian carcinomas but may have an important role in the progression of the disease.

DNA flow cytometric analysis of serous ovarian tumors of low malignant potential

BACKGROUND

Ovarian serous tumors of low malignant potential (STLMP) occasionally progress; a small percentage of patients die of the tumor. There is no known way to predict which tumors will progress.

METHODS

Forty STLMP were analyzed by DNA flow cytometry and compared with 26 serous carcinomas.

RESULTS

Forty percent of Stage I STLMP and 40% of Stage III STLMP were DNA aneuploid as compared to 54% of serous carcinomas. Aneuploidy was found in 50% of STLMP that progressed and in 38% of neoplasms that did not progress. Four of the 30 Stage I STLMP progressed, and 3 of the 4 were aneuploid; whereas, of the 26 Stage I STLMP that did not progress, 9 were DNA aneuploid. Stage III STLMP were aneuploid in 4 out of 10 instances (40%). Aneuploidy was not related to progression as three of four DNA diploid tumors progressed, and three of six that did not progress were aneuploid. Thirteen of 16 aneuploid STLMP had peridiploid aneuploid populations. The mean follow-up periods were 14.3 years for Stage I STLMP and 8.3 years for Stage III STLMP:

CONCLUSIONS

DNA aneuploidy in Stages I and III STLMP does not identify neoplasms likely to relapse with sufficient frequency to be useful in identifying those patients at high risk for relapse.

Immunolocalization of c-myc oncoprotein in mucinous and serous adenocarcinomas of the ovary

Activation of c-myc oncogene has been reported in increasing numbers of human ovarian carcinomas and appears to play a role in the biologic behavior of the neoplasms. We have studied the immunohistochemical localization of p-62c-myc, the gene product of c-myc, in 44 cases of serous and mucinous cystadenoma, adenocarcinoma of low malignant potential, and invasive adenocarcinoma, using a monoclonal antibody raised to a synthetic human p62c-myc sequence (Myc 1-6E10). Both serous and mucinous cystadenomas demonstrated a higher frequency of nuclear localization than did carcinomas, which showed much greater cytoplasmic staining, while tumors of low malignant potential showed an intermediate pattern. However, the observed differences did not reach statistical significance. No significant correlation was observed between intracellular localization patterns of p62c-myc and histologic and nuclear grades and mitotic activity in the cases of carcinoma. Great care should be taken in the interpretation of immunohistochemical analysis of oncogene products, especially when attempting to correlate the findings with biologic tumor behavior.

c-myc over-expression in human primary ovarian tumours: its relevance to tumour progression

Expression of the c-myc gene was analyzed in 56 human primary ovarian cancer tissues, including 51 common epithelial and 5 non-epithelial tumours to determine molecular events in the carcinogenic process in ovaries. Over-expression of the c-myc gene was found in 37.3% of all ovarian tumour tissues, and in 63.5% of serous adenocarcinoma tissues. Significant over-expression of the c-myc gene at Stage III compared with other stages, and one remarkable case of over-expression in a serous tumour of low malignant potential suggest that c-myc expression is temporarily activated at some stage(s) during tumorigenesis of ovarian cancer, especially of serous tumours.

Oncogenes in gynecological tumors

Evidence is increasing that proto-oncogenes and cancer suppressor genes are involved in the development and/or progression of gynecological malignancies. While histopathologic examination remains an indispensable tool of the surgical pathologist in the diagnosis and evaluation of patients with gynecological malignancies, the advancement to technology and the development of new knowledge regarding neoplastic transformation are providing a basis for new opportunities to improve patients care. These new opportunities will depend on the use of the skills and reagents developed in the basic medical science laboratories. Thus, it is important for those in the field of diagnostic pathology to begin to acquire a knowledge of proto-oncogenes and cancer suppressor genes as well as a basic understanding of the techniques used to detect and evaluate them.

Comparative evaluation of fresh, fixed, and cryopreserved solid tumor cells for reliable flow cytometry of DNA and tumor associated antigen

Five different protocols for the short-term preservation of cells used for multiparameter flow cytometric assay of tumour associated antigens (TAA) and DNA were assessed in cell suspensions prepared by mechanical disaggregation of 15 gynecological tumors. The protocols at 4 degrees C were 1) storage in buffer, 2) storage in 50% methanol, and 3) storage in buffer after formalin fixation. Tissues were also cryopreserved as cell suspensions and tissue blocks. When the TAA expression and DNA histograms of the preserved cells were compared with those in fresh cell suspensions, cryopreservation was found to be the best method: TAA expression was well preserved and there was a good correlation between TAA expression and the quality of the DNA histograms, respectively, in fresh and cryopreserved cells (RS: 0.82-0.91, P less than 0.001 for all TAAs). The cell suspensions preserved at 4 degrees C all showed a significant increase in background fluorescence (P less than 0.05) and a reduction in the TAA specific fluorescence (P less than 0.011). Methanol fixation was better than buffered formalin for the proteins studied, though both gave significantly worse results than cryopreservation. The quality of these cell suspensions and the correlation with TAA measurements in fresh cell suspensions deteriorated progressively with time, particularly if they were stored more than a week.

Multiparameter flow-cytometric quantitation of epidermal growth factor receptor and c-erbB-2 oncoprotein in normal and neoplastic tissues of the female genital tract

A novel multiparameter flow-cytometric method was used to quantify the expression of epidermal growth factor receptor (EGFR) and c-erbB-2 oncoprotein on 85 cryopreserved normal tissues (30 ovary, 29 endometrium, 16 cervix) and 67 carcinomas (31 ovarian, 18 cervical, 15 endometrial, 3 vulvar). Overexpression of the EGFR and c-erbB-2 oncoproteins was found in respectively 3/31 (9%) and 10/31 (32%) ovarian carcinomas, 13/18 (72%) and 7/18 (38%) cervical carcinomas, and 2/15 (13%) and 2/15 (13%) endometrial carcinomas. Oncoprotein expression was significantly higher in the malignant tumors (for all tumor sites) than in the corresponding normal tissues (P less than 0.034 for all combinations). Aneuploid tumors expressed levels of EGFR and c-erbB-2 oncoprotein significantly higher than those of DNA diploid tumors (P = 0.042 and P = 0.048, respectively). Oncoprotein could be detected in nearly all normal tissues: expression was higher in premenopausal than in postmenopausal patients (EGFR, P = 0.07; c-erbB-2, P less than 0.001). The present study supports the idea that EGFR and c-erbB-2 may play an important role in the autocrine, paracrine, and/or endocrine growth control and differentiation of normal tissues. Alteration in the expression of these oncoproteins is probably involved in malignant transformation and tumorigenesis.

Multi-parameter flow cytometric quantitation of the expression of the tumor-associated antigen SM3 in normal and neoplastic ovarian tissues. A comparison with HMFG1 and HMFG2

SM3 is a monoclonal antibody that reacts with a peptide epitope in the core protein of polymorphic epithelial mucin. Multi-parameter flow cytometry was used to characterize the expression of SM3 and compare it with two related tumor-associated antigens, HMFG1 and HMFG2, in cell suspensions of 44 malignant ovarian tumors, 15 benign ovarian tumors, and 16 normal ovaries. Tumor-associated antigen expression was significantly higher in malignant ovarian neoplasms than in benign neoplasms (P less than 0.001 for all three antigens). SM3 was expressed more specifically in malignant than benign tumors but had a lower affinity than HMFG1 and HMFG2. Multi-parameter flow cytometric evaluation of a panel of monoclonal antibodies can be used to help in choosing the best antibody for immunohistochemistry, imaging, and eventually treatment of ovarian tumors.

Hereditary ovarian cancer. Pedigree studies, Part II

Hereditary ovarian carcinoma is heterogenous. There are at least three genetic variants, namely, hereditary site-specific ovarian carcinoma, hereditary breast/ovarian carcinoma syndrome, and Lynch syndrome II. Early age of onset characterizes these disorders. A crucial hallmark of these disorders is the integral association of extraovarian cancers, such as carcinoma of the endometrium and colon in Lynch syndrome II. We have described 24 pedigrees of ovarian cancer-prone families in order to depict the several differing heterogenous variants. Interest in hereditary ovarian cancer has increased remarkably, due in part to the fact that its surveillance has been wholly unsatisfactory, as have therapeutic measures. Prevention through prophylactic oophorectomy offers hope. However, there is a risk for extraovarian peritoneal serous papillary carcinoma, consonant with primary cancer of the ovary. This must be discussed with these at-risk patients. Until a biomarker of acceptable sensitivity and specificity is identified, the family history must remain the key to hereditary ovarian cancer diagnosis.

Tissue preparation for simultaneous flow cytometric quantitation of tumour associated antigens and DNA in solid tumours

A multiparameter flow cytometric assay for the simultaneous study of tumour associated antigens (TAA) and DNA in fresh solid tumours was devised. Cell suspensions were prepared by disaggregating unfixed solid tumour samples mechanically over a stainless steel mesh. Indirect immunofluorescence was used to identify the TAA, and DNA was stained with propidium iodide. Cell morphology was well preserved, cell clumping was negligible, and high quality indirect immunofluorescence quality indirect immunofluorescence and DNA staining were obtained. The technique is simple, rapid, and reproducible. Multiparameter assays can be developed to study prognostic indicators such as membrane oncoproteins, receptors, and multidrug resistance in solid tumours. With a suitable panel of antibodies the technique might become an aid in the differential diagnosis and biochemical diagnosis of some solid tumours.

Protooncogene amplification and tumor ploidy in human ovarian neoplasms

DNA from 24 ovarian tumors, including 16 carcinomas, was examined for amplification of the proto-oncogenes c-myc, int-2, and rc-erbB-2. All cases of carcinoma were also examined by flow cytometry for DNA ploidy and cell cycle analysis, and eight cases of carcinoma were examined for estrogen and progesterone receptors. Protooncogene amplification was not detected in the DNA of benign ovarian neoplasms, or of ovarian carcinomas with low malignant potential. Amplification of c-myc was detected in six of 12 cases of invasive carcinoma, int-2 amplification was present in one case, and c-erbB-2 amplification was not detected in any case. Among the seven cases evidencing protooncogene amplification, three cases showed aneuploidy in tumor DNA, while four showed diploidy. Two cases which showed aneuploidy in tumor DNA did not demonstrate any degree of protooncogene amplification. Protooncogene amplification was frequently associated with morphologic nuclear anaplasia and high mitotic count. Six of the seven cases demonstrating c-myc or int-2 were of the serous type or showed some degree of serous differentiation, while none of the four cases of purely mucinous carcinoma had evidence of amplification. While the total number of cases in the study was limited, it would appear from the trend demonstrated by the data that protooncogene amplification (particularly c-myc) may be involved in the pathogenesis of aggressive common epithelial tumors of the ovary.

Novel screening strategies for early ovarian cancer by transabdominal ultrasonography

Data collected during a prospective study to assess the efficacy of detecting early ovarian cancer by transabdominal ultrasonography have been used to refine and extend the screening procedure. The analysis was based on results from 5479 self-referred asymptomatic women, who were scheduled to undergo three annual screens consisting of one or more ultrasound scans. A positive result (based mainly on the presence of abnormal morphology) was obtained at 338 screens (326 women). Five patients with primary ovarian cancer (four stage 1a, one stage 1b; two at screen 1, three at screen 2) were identified (prevalence 0.09%). The apparent detection rate was 100% and the false-positive rate (FPR) was 3.5% at screen 1 and 2.3% overall. The use of abnormal morphology, or the maximum ovarian volume (MOV) greater than 96th centile as alternative criteria for a positive screen result, together with a defined volume change at rescan (VC) would give a FPR of 3.1% at screen 1 and 2.0% overall. The use of abnormal morphology alone at scan 1 and VC at rescan would give an overall FPR of 1.6%. The odds that a positive screen result would indicate the presence of an ovarian mass, a benign tumour, any ovarian cancer or primary ovarian cancer would be about 4 to 1, 2 to 1, 1 to 26, and 1 to 50 respectively. The results provide a more rational basis for the application and development of screening procedures for early ovarian cancer in both pre- and post-menopausal women.

Growth factors and oncogenes in human solid tumors: clinical aspects

Growth factors, growth factor receptors and oncogenes have been extensively studied in human tumors for some years. The purpose of this paper is to review the clinical results obtained in human cancers and their predisposing conditions or high risk groups as well as their relation with clinical, pathological characteristics and their prognosis.

Flow cytometry using paraffin-embedded tissue: five years on

The use of paraffin-embedded tissue for flow cytometry is reviewed. A number of technical modifications of the original 1983 method have been described, aimed at improving the accuracy of DNA measurements by minimizing cell debris or reducing coefficients of variation, and at simplifying sample preparation. Over 100 clinical studies have now been reported, mainly assessing the effect of DNA index on prognosis, and those published up until mid-1988 are summarized in an appendix. More recently there have been developments in the use of monoclonal antibodies to measure oncogene products or proliferation markers in addition to DNA content. Detailed clinical evaluation and standardization of these more sophisticated methods is still some way ahead, but as was the case with DNA index, the use of archival material from patients whose outcome is already known should speed this process.