Immunohistochemical localization of c-erbB-2 protein and epidermal growth factor receptor in normal surface epithelium, surface inclusion cysts, and common epithelial tumours of the ovary

Histological and immunohistochemical evaluation of granulosa cells during different stages of folliculogenesis in bovine ovaries

Bovine granulosa cells (GC) vary in their morphological aspect during different stages of folliculogenesis. In this study, 10 morphologically normal bovine ovaries were collected to study the structural aspects of different stages of GC using intermediate filament protein antibodies including cytokeratin AE1/AE3 (AE1/AE3), vimentin, nectin-4 and desmin. Hormonal immunolocalization was assessed using the immunomarkers anti-Müllerian hormone (AMH) and inhibin alpha. In addition, tumour markers and proliferation markers using c-erbB-2 oncoprotein and proliferating cell nuclear antigen, respectively, were investigated. The immunolabelling of AE1/AE3 in GC was strongest in the early follicle stage and gradually decreased when reaching the Graafian follicle stage. Its immunolabelling increased again as the stage progressed from stage I to stage III. The immunolabelling of inhibin alpha was inversely proportional to that of AE1/AE3 in the developing ovarian follicles as their immunolabelling is opposite to each other during folliculogenesis. AMH was immunopositive in almost all GC stages in different intensities and percentages, except for some negative staining in the atretic IV follicles. The atretic IV follicle is a unique type of atretic follicle that shows Call-Exner body formation, which was mainly found in older cows in this study. The distinct patterns of immunoreactivity for various types of immunomarkers in the different GC stages will play an important role in diagnostic assistance of various follicle conditions, including cystic ovaries and GC tumours.

Hoxa5: A Key Player in Development and Disease

A critical position in the developmental hierarchy is occupied by the Hox genes, which encode transcription factors. Hox genes are crucial in specifying regional identity along the embryonic axes and in regulating morphogenesis. In mouse, targeted mutations of Hox genes cause skeletal transformations and organ defects that can impair viability. Here, we present the current knowledge about the Hoxa5 gene, a paradigm for the function and the regulation of Hox genes. The phenotypic survey of Hoxa5-/- mice has unveiled its critical role in the regional specification of the skeleton and in organogenesis. Most Hoxa5-/- mice die at birth from respiratory distress due to tracheal and lung dysmorphogenesis and impaired diaphragm innervation. The severity of the phenotype establishes that Hoxa5 plays a predominant role in lung organogenesis versus other Hox genes. Hoxa5 also governs digestive tract morphogenesis, thyroid and mammary glands development, and ovary homeostasis. Deregulated Hoxa5 expression is reported in cancers, indicating Hoxa5 involvement in tumor predisposition and progression. The dynamic Hoxa5 expression profile is under the transcriptional control of multiple cis-acting sequences and trans-acting regulators. It is also modulated by epigenetic mechanisms, implicating chromatin modifications and microRNAs. Finally, lncRNAs originating from alternative splicing and distal promoters encompass the Hoxa5 locus.

Comprehensive profiling of EGFR/HER receptors for personalized treatment of gynecologic cancers

The primary gynecologic cancers include cancers of the endometrium, ovary, and cervix. Worldwide, cervical cancer is the most common gynecologic cancer, whereas endometrial cancer is the most common in the US. Ovarian cancer is the fifth most deadly cancer in women, with 5-year survival rates for advanced disease at only 27 %. As such, there is an urgent need for reliable screening tools and novel targeted therapeutic regimens for these malignancies. The epidermal growth factor receptor (EGFR)/human EGFR (HER) family of receptors has been associated with the development and progression of many solid tumors. Despite clear roles for these receptors in other cancers, the expression of HER family members in gynecologic cancers and their relationship with disease stage, grade, and response to treatment remain controversial. In this review, we describe the existing evidence for the use of HER family members as diagnostic and prognostic indicators as well as their potential as therapeutic targets in gynecologic cancers.

HER2 expression beyond breast cancer: therapeutic implications for gynecologic malignancies

HER2 or ErbB2 is a member of the epidermal growth factor family and is overexpressed in subsets of breast, ovarian, gastric, colorectal, pancreatic, and endometrial cancers. HER2 regulates signaling through several pathways (Ras/Raf/mitogen-activated protein kinase and phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin pathways) associated with cell survival and proliferation. HER2-overexpressed and/or gene-amplified tumors are generally regarded as biologically aggressive neoplasms. In breast, cervical, endometrial, and ovarian cancer, there have been several studies linking the amplification of the c-erbB2 gene with chemoresistance and overall poor survival. Tyrosine kinase inhibitors and immunotherapy with monoclonal antibodies targeting HER2 hold promise for patients harboring these aggressive neoplasms. Trastuzumab combined with cytotoxic chemotherapy agents or conjugated with radioactive isotopes is currently being investigated in clinical trials of several tumor types.

Network analysis identifies an HSP90-central hub susceptible in ovarian cancer

PURPOSE

Epithelial ovarian cancer (EOC) is usually detected at an advanced stage and is frequently lethal. Although many patients respond to initial surgery and standard chemotherapy consisting of a platinum-based agent and a taxane, most experience recurrence and eventually treatment-resistant disease. Although there have been numerous efforts to apply protein-targeted agents in EOC, these studies have so far documented little efficacy. Our goal was to identify broadly susceptible signaling proteins or pathways in EOC.

EXPERIMENTAL DESIGN

As a new approach, we conducted data-mining meta-analyses integrating results from multiple siRNA screens to identify gene targets that showed significant inhibition of cell growth. On the basis of this meta-analysis, we established that many genes with such activity were clients of the protein chaperone HSP90. We therefore assessed ganetespib, a clinically promising second-generation small-molecule HSP90 inhibitor, for activity against EOC, both as a single agent and in combination with cytotoxic and targeted therapeutic agents.

RESULTS

Ganetespib significantly reduced cell growth, induced cell-cycle arrest and apoptosis in vitro, inhibited growth of orthotopic xenografts and spontaneous ovarian tumors in transgenic mice in vivo, and inhibited expression and activation of numerous proteins linked to EOC progression. Importantly, paclitaxel significantly potentiated ganetespib activity in cultured cells and tumors. Moreover, combined treatment of cells with ganetespib and siRNAs or small molecules inhibiting genes identified in the meta-analysis in several cases resulted in enhanced activity.

CONCLUSION

These results strongly support investigation of ganetespib, a single-targeted agent with effects on numerous proteins and pathways, in augmenting standard EOC therapies.

Epidermal growth factor receptor-mediated membrane type 1 matrix metalloproteinase endocytosis regulates the transition between invasive versus expansive growth of ovarian carcinoma cells in three-dimensional collagen

The epidermal growth factor receptor (EGFR) is overexpressed in ovarian carcinomas and promotes cellular responses that contribute to ovarian cancer pathobiology. In addition to modulation of mitogenic and motogenic behavior, emerging data identify EGFR activation as a novel mechanism for rapid modification of the cell surface proteome. The transmembrane collagenase membrane type 1 matrix metalloproteinase (MT1-MMP, MMP-14) is a major contributor to pericelluar proteolysis in the ovarian carcinoma microenvironment and is subjected to extensive posttranslational regulation. In the present study, the contribution of EGFR activation to control of MT1-MMP cell surface dynamics was investigated. Unstimulated ovarian cancer cells display caveolar colocalization of EGFR and MT1-MMP, whereas EGFR activation prompts internalization via distinct endocytic pathways. EGF treatment results in phosphorylation of the MT1-MMP cytoplasmic tail, and cells expressing a tyrosine mutated form of MT1-MMP (MT1-MMP-Y(573)F) exhibit defective MT1-MMP internalization. As a result of sustained cell surface MT1-MMP activity, a phenotypic epithelial-mesenchymal transition is observed, characterized by enhanced migration and collagen invasion, whereas growth within three-dimensional collagen gels is inhibited. These data support an EGFR-dependent mechanism for regulation of the transition between invasive and expansive growth of ovarian carcinoma cells via modulation of MT1-MMP cell surface dynamics.

Risk factors for ovarian cancer: an overview with emphasis on hormonal factors

Ovarian cancer is the fifth most frequently occurring cancer among women and leading cause of gynecological cancer deaths in North America. Although the etiology of ovarian cancer is not clear, certain factors are implicated in the etiology of this disease, such as ovulation, gonadotropic and steroid hormones, germ cell depletion, oncogenes and tumor suppressor genes, growth factors, cytokines, and environmental agents. Family history of breast or ovarian cancer is a prominent risk factor for ovarian cancer, with 5-10% of ovarian cancers due to heritable risk. Reproductive factors such as age at menopause and infertility contribute to greater risk of ovarian cancer, whereas pregnancy, tubal ligation, and hysterectomy reduce risk. Oral contraceptive (OC) use has clearly been shown to be protective against ovarian cancer. In contrast, large epidemiologic studies found hormone replacement therapy (HRT) to be a greater risk factor for ovarian cancer. The marked influence of hormones and reproductive factors on ovarian cancer suggests that endocrine disrupters may impact risk; however, there is a notable lack of research in this area. Lifestyle factors such as cigarette smoking, obesity, and diet may affect ovarian cancer risk. Exposure to certain environmental agents such as talc, pesticides, and herbicides may increase risk of ovarian cancer; however, these studies are limited. Further research is needed to strengthen the database of information from which an assessment of environmental and toxicological risk factors for ovarian cancer can be made.

Clinical implications of the ErbB/epidermal growth factor (EGF) receptor family and its ligands in ovarian cancer

The ERBB or EGF receptor (EGFR) proto-oncogene family, which consists of four structurally-related transmembrane receptors (i.e., EGFR, ErbB2, ErbB3, and ErbB4), plays an etiological role in the molecular pathogenesis of cancer and is a key therapeutic target in many types of cancer, including ovarian cancer. These ErbB/EGF receptor tyrosine kinases play important physiologic roles in cell proliferation, survival, adhesion, motility, invasion, and angiogenesis. It is, therefore, not surprising that gene amplification, genetic mutation, and altered transcription/translation result in aberrant ErbB/EGF receptor expression and/or signal transduction, contributing to the development of malignant transformation. Clinically, the diagnostic, prognostic, and theragnostic significance of any single ErbB receptor and/or ErbB ligand is controversial, but generally, ErbB receptor overexpression has been correlated with poor prognosis and decreased therapeutic responsiveness in ovarian cancer patients. Thus, anticancer agents targeting ErbB/EGF receptors hold great promise for personalized cancer treatment. Yet, challenges remain in designing prospective clinical trials to assess the clinical utility of ErbB receptors and their ligands to diagnose cancer; to predict progression-free and overall survival, therapeutic responsiveness, and disease recurrence; and to monitor treatment responsiveness. Here, we review the tissue expression and serum biomarker studies that have evaluated the diagnostic, prognostic, and theragnostic utility of ErbB/EGF receptors, their circulating soluble isoforms (sEGFR/sErbBs), and their cognate ligands in ovarian cancer patients.

Histomorphological and Immunohistochemical Characterization of Equine Granulosa Cell Tumours

Benign (n=33) and malignant metastasizing (n=1) granulosa cell tumours (GCTs) from 34 mares aged 3-21 years, and normal (control) ovaries from nine mares aged 3-10 years, were examined histologically and immunohistochemically (for inhibin alpha, glutathione S-transferase alpha [GSTalpha], c-erbB-2 oncoprotein [cerb], cytokeratin, vimentin, desmin and alpha-actin), the results being related where appropriate to clinical signs and endocrinological data. Availability permitting, serum samples from GCT-affected mares before and several weeks after ovariectomy were examined for the following hormones: oestradiol, progesterone and testosterone (by radioimmunoassay); and inhibin B (by a cross-reactive ELISA). Histological examination revealed that the GCTs were predominantly well differentiated neoplasms. The metastasizing GCT differed immunohistochemically from the benign GCTs in respect of the expression patterns of vimentin, cerb and GSTalpha in the granulosa cells. A notable feature was the presence of Leydig-like cells in mares with stallion-like behaviour or elevated serum testosterone, or both. GSTalpha immunolabelling indicated that the Leydig-like cells were potential producers of steroid hormone. From the immunohistochemical and endocrinological findings it was concluded that GCTs produce abnormally high concentrations of inhibin, which reduce the release of follicle-stimulating hormone, leading to atrophy of the contralateral ovary-a finding in 27 of the mares.

Loss of ovarian function and the risk of ovarian cancer

Animal models with premature ovarian failure resulting from the loss or depletion of germ cells consistently develop ovarian surface epithelial cell hyperplasia with invasion into the stroma and the development of ovarian tubular adenomas. In human ovaries, deep epithelial invaginations and inclusion cysts occur at increasing frequency with age and are thought to be the structures from which the majority of ovarian cancers arise. A feature that is common to these animal models and to post-menopausal women is a deficiency in the number of oocytes. The potential consequences of the loss or depletion of female germ cells, naturally or otherwise, include failure of follicle development, significant reductions in oestrogen and progesterone levels and elevation of circulating levels of gonadotropins. This review will consider the way in which these structural and hormonal changes affect ovarian cancer risk. Some lessons may be learned from gonad formation, since notable similarities exist between ovarian tumorigenesis and embryonic gonadogenesis including fragmentation of the basement membrane underlying the coelomic (surface) epithelium, the potential for the migration of epithelial cells into the gonad and the importance of the germ cells for the regulation of ovarian structure and function.

Her-2/neu expression and amplification in early stage ovarian surface epithelial neoplasms

OBJECTIVE

The aim of this study is to examine Her-2/neu gene amplification and protein overexpression in a spectrum of ovarian neoplasms using both immunohistochemical (IHC) and fluorescence in situ hybridization (FISH) techniques that are FDA approved. This study is focused on early stage tumors including both carcinomas and borderline tumors.

METHODS

FDA-approved IHC and FISH for Her-2/neu were performed on formalin-fixed, paraffin-embedded tissue from 79 ovarian neoplasms representing a broad spectrum of tumor types as well as four normal ovaries. All tumors were either stage I or stage II. Tumor and normal tissue were studied collectively using a tissue microarray (TMA). HercepTest (DAKO) and PathVysion Her-2/neu probe kit (Vysis Inc.) were used for IHC and FISH analysis.

RESULTS

FISH analysis of serous carcinomas demonstrated Her-2/neu gene amplification in 3 (18%) of 17 cases. Two of three cases showing Her-2/neu gene amplification were scored 1+ using IHC, while the remaining case was scored as 0. Analysis of endometrioid carcinomas demonstrated Her-2/neu amplification using FISH in 1 of 10 (10%) cases. IHC in this case was scored 2+ (positive). None of the remaining 44 tumors, including clear cell carcinoma (n = 12), transitional cell carcinoma (n = 1), mixed epithelial carcinoma (n = 7), carcinoma not otherwise specified (n = 1), and 31 borderline tumors (mucinous, n = 17; endometrioid, n = 7; serous, n = 7), showed Her-2/neu gene amplification or protein overexpression. Normal ovaries were negative as well.

CONCLUSIONS

Amplification of Her-2/neu in early stage ovarian neoplasms is infrequent, 6.7% overall. Due to the limited number of informative cases, we were unable to determine the clinical significance of Her-2/neu amplification in this study. Her-2/neu amplification was restricted to carcinomas and was not encountered in ovarian borderline tumors.

Concentrations of alpha-fetoprotein, insulin-like growth factor binding protein-3, c-erbB-2, and epidermal growth factor in serum of patients with endometriosis

OBJECTIVE

Endometriosis, although it is a benign disorder, shares many similarities with cancer. There is increasing levels of evidence suggesting that some circulating factors involved in gynecologic cancers, such as alpha-fetoprotein (AFP), insulin-like growth factor binding protein-3 (IGFBP-3), c-erbB-2 (HER-2/neu), and epidermal growth factor (EGF), could also play a role in endometriosis. Hence, the present study was aimed at evaluating whether the levels of these molecules are modulated in the serum of patients with endometriosis.

METHODS

Levels of AFP, IGFBP-3, c-erbB-2, and EGF were determined by enzyme-linked immunosorbent assay in serum from 36 subjects with surgically confirmed endometriosis and 36 controls with no surgical evidence of the disease. In addition, information such as demographic characteristics, personal habits, menstrual characteristics, and clinical profile was collected from each participating subject.

RESULTS

No significant difference was found between serum levels of AFP, IGFBP-3, c-erbB-2, and EGF in patients with endometriosis and controls, even when we adjusted for potential confounders and took into account the menstrual cycle. Moreover, no correlation was observed between the serum concentrations of these molecules and the stage of the disease. However, a correlation was detected between soluble levels of IGFBP-3 and presence of uterine leiomyoma.

CONCLUSION

Although AFP, IGFBP-3, c-erbB-2, and EGF are not altered in the circulation of patients with endometriosis, their involvement in the development of endometriotic lesions cannot be excluded.

A monoclonal antibody recognizing human cancers with amplification/overexpression of the human epidermal growth factor receptor

Epidermal growth factor receptor (EGFR) has attracted considerable attention as a target for cancer therapy. Wild-type (wt)EGFR is amplified/overexpressed in a number of tumor types, and several mutant forms of the coding gene have been found, with DeltaEGFR, a deletion mutation lacking exons 2-7 of the external domain, being the most common and particularly associated with glioblastoma. We generated monoclonal antibodies (mAbs) against NR6(DeltaEGFR) (mouse fibroblast line NR6 transfected with DeltaEGFR). mAb 806 with selective reactivity for NR6(DeltaEGFR) in mixed hemadsorption assays, fluorescence-activated cell sorting, Western blot, and immunohistochemistry was analyzed in detail and compared with mAbs 528 (anti-wtEGFR) and DH8.3 (anti-DeltaEGFR). In xenograft tumors and molecularly pretyped glioblastomas, the reactivity pattern was as follows: 528 reactive with amplified and nonamplified wtEGFR; DH8.3 reactive with DeltaEGFR; and 806 reactive with amplified/overexpressed wtEGFR (with or without DeltaEGFR). In normal tissues, 528 but not DH8.3 or 806 was widely reactive with many organs, e.g., liver expressing high EGFR levels. In glioblastoma and non-CNS tumor panels, 806 was reactive with a high proportion of glioblastomas and a substantial number of epithelial cancers of lung and of head and neck. DH8.3 reactivity was restricted to DeltaEGFR-positive glioblastoma. Thus, 806 represents a category of mAbs that recognizes tumors with EGFR amplification/overexpression but not normal tissues or tumors with normal EGFR levels. Our study also indicates that DeltaEGFR is restricted to glioblastoma, in contrast to other reports that this mutation is found in tumors outside the brain.

Occult carcinoma in prophylactic oophorectomy specimens: prevalence and association with BRCA germline mutation status

Prophylactic oophorectomy (PO) is an option for women at increased risk for ovarian carcinoma. In this study the value of intensive pathologic examination of PO specimens and accompanying resected tissues in the identification of occult carcinoma and any association of occult carcinoma with BRCA germline mutation status were ascertained. Specimens from 60 consecutive PO patients, who were not suspected of having any ovarian tumor at the time of surgery, were subjected to standardized, complete pathologic examination in a prospective study over an 8-year period. Extra-ovarian tissues were examined as well, but they were not subject to the same standardized protocol. Any occult carcinoma of the ovaries or fallopian tubes was noted. The BRCA status and follow-up of patients were obtained, if available. Fifty-five of the 60 PO specimens did not show any evidence of malignancy. Of the 32 patients in this group followed for >1 year, all are alive and well. The remaining five patients, all BRCA1 mutation positive, showed occult carcinoma of the ovaries and/or in situ or invasive carcinoma of a fallopian tube. One of these five patients has died of abdominal carcinomatosis; four continue to be well, but follow-up is <4 years in all cases. Occult carcinoma is present in a small proportion of BRCA-positive or unknown PO patients and may be of prognostic significance. The entire ovaries and tubes from PO patients should be submitted for histologic examination to identify malignancy.

Expression and action of transforming growth factor alpha in normal ovarian surface epithelium and ovarian cancer

Greater than 95% of ovarian cancers originate in the epithelial cells on the surface of the ovary. The current study investigates the expression and action of transforming growth factor alpha (TGFalpha) in ovarian surface epithelium (OSE) and the underlying stroma in both normal and tumorigenic ovarian tissues. Normal bovine ovaries are used in the current study as a model system to investigate normal OSE functions. Transforming growth factor alpha and its receptor, the epidermal growth factor receptor (EGFR), were detected in the OSE from normal ovaries by immunocytochemistry (ICC). Ovarian stromal tissue also contained reduced but positive TGFalpha and EGFR immunostaining. To examine TGFalpha and EGFR gene expression, RNA was collected from normal bovine OSE and ovarian stromal cells. The TGFalpha and EGFR transcripts were detected in both fresh and cultured OSE and stromal cells by a sensitive quantitative reverse transcription polymerase chain reaction (QRT-PCR) assay. Transforming growth factor alpha gene expression was found to be high in freshly isolated OSE, but low in freshly isolated stroma. In contrast, EGFR expression was higher in the stroma compared to the OSE. Both the ICC and QRT-PCR indicate that normal OSE express high levels of TGFalpha in vivo and in vitro. In vitro, normal ovarian stromal cells develop the capacity to express high levels of EGFR. Human ovarian tumors from stage II, stage III, and stage IV ovarian cancer cases were found to express TGFalpha and EGFR protein in the epithelial cell component of the tumor by ICC analysis. The stromal cell component of human ovarian tumors contained little or no TGFalpha/EGFR immunostaining. Observations suggest that tumor progression may in part require autocrine stimulation of the epithelia. Transforming growth factor alpha was found to stimulate the growth of normal bovine OSE and stroma cells to the same level as epidermal growth factor. Two ovarian cancer cell lines, SKOV3 and OCC1, were also stimulated to proliferate in response to TGFalpha. Transforming growth factor alpha was also found to stimulate the expression of two growth factors previously shown to be produced by OSE. Transforming growth factor alpha stimulates both kit ligand/stem cell factor and keratinocyte growth factor production by OSE. The effect of hormones on TGFalpha and EGFR expression by the OSE was also examined. Human chorionic gonadotropin stimulated TGFalpha expression, but not FSH. Both hCG and FSH stimulated EGFR expression by OSE. Combined observations suggest a role of systemic hormones and a locally produced growth factor, TGFalpha, in OSE biology. Insight is also provided into how the OSE may develop abnormal growth characteristics involved in the onset and progression of ovarian cancer.

An immunohistochemical study of the rete ovarii and epoophoron

A study to compare the immuno-histochemical profile of the human rete ovarii, and epoophoron, with the Fallopian tube and ovarian surface epithelium was performed with 31 antibodies and antisera. A reaction was present in the epithelial cytoplasm of the rete ovarii and epoophoron of mesonephric origin, for vimentin, GFAP, cytokeratin markers, (AE1/AE3, MNF116; Cam 5.2, 34 beta E12 and for the monospecific antibodies to cytokeratins 7 and 19), heat shock protein 27, in the cell membrane for HBME-1, EMA and in the subepithelial collagen for collagen IV. Reactions were present only in the epithelium in the rete ovarii for EGFR (one case) and CA-125 (four cases). A reaction was present in the epithelium of the epoophoron only for Ber-EP-4 and S100. There was no reaction with antibodies for desmin, neurofilament protein, cytokeratins 20 or 14, actin, calretinin, E-cadherin, C-erb-B2, or CEA (monoclonal and polyclonal reagents). The immuno-histochemical profile of the Fallopian tube was consistent with its para-mesonephric origin and that in the ovarian surface epithelium was consistent with a proposed modified mesothelial origin. This study provides an immunohistochemical profile of these structures with a large panel of commonly available antibodies and antisera, confirming and extending the findings described in previous studies.

Amplification and expression of the c-erbB-2 oncogene in Müllerian-derived genital-tract tumors

This study focused on 18 uterine corpus tumors and 7 ovarian endometrioid tumors, all of them malignant and Müllerian derived. Differential polymerase chain reaction (DPCR), dot blot hybridization, and immunohistochemical technique were employed to determine c-erbB-2 amplification and expression. Of 25 Müllerian-derived tumors, 17 (68.0%) demonstrated amplified c-erbB-2 (two to eight copies) by DPCR. These 25 samples were reexamined by dot blot and immunohistochemical technique, revealing c-erbB-2 amplification and expression of to be 52.0 and 40.0%, respectively. There seemed to be a slight correlation between the amplification and expression of c-erbB-2 and patient survival. Although c-erbB-2 was frequently present in Müllerian-derived genital-tract tumors, it is uncertain whether this oncogene may serve as their sole prognostic marker. The question remains whether c-erbB-2 alone, or in conjunction with other oncogenes or suppressor genes, accounts for the pathogenesis of Müllerian-derived tumors. However, these results suggest for the first time in the literature that DPCR is a sensitive enough technique for detecting c-erbB-2 amplification in M ullerian-derived tumors.

Coexpression of the HER-2 gene product, p185HER-2, and epidermal growth factor receptor, p170EGF-R, on epithelial ovarian cancers and normal tissues

Monoclonal antibodies (MAbs) and immunoconjugates reactive with different antigens expressed by neoplastic cells can inhibit tumor growth. Use of these agents in combination with one another or with chemotherapy can exert additive or synergistic cytotoxicity against tumor cells. An augmented therapeutic activity with favorable therapeutic index might be attained when coexpression is observed on tumor cells, but not in normal tissues. In this study frozen sections of 19 ovarian cancers (2 stage I, 10 stage III, 2 stage IV, and 5 recurrent), as well as 29 normal tissues, were evaluated by immunohistochemistry using 11 distinct MAbs against HER-2/p185 and 2 antibodies against EGF-R/p170 to assess coexpression of these receptors. HER-2/p185 expression was detected in 5 to 100% of ovarian cancers and 0 to 50% of normal ovarian epithelia, depending on the antibody used. EGF-R/p170 expression was detected in approximately 70% of cancers and 40% of normal ovaries by both antibodies. Coexpression of p185 and p170 was observed in 47-68% of ovarian cancers and 9-18% of normal ovarian epithelial specimens depending upon the combination of antibodies used. Staining of 273 specimens from 29 normal tissues indicated that coexpression of HER-2 and EGF-R is rare. Normal tissues that coexpressed both receptors in > or =50% of the cases included cervix, endometrium, esophagus, skin, and prostate. These data confirm that HER-2 and EGF-R are more frequently expressed in advanced ovarian cancers than in normal ovarian epithelium and a significant fraction of these tumors coexpress both HER-2 and EGF-R.

Immunohistochemical study of c-erb B-2 expression in malignant mixed müllerian tumors of the female genital tract

OBJECTIVE

To study the expression of c-erb B-2 in gynecologic malignancies, especially in malignant mixed müllerian tumors (MMTs).

METHODS

Using immunohistochemical techniques, we examined 6 cases of primary MMT, 6 cases of leiomyosarcoma (LMS), 7 cases of endometrial adenocarcinomas, and 10 cases of normal endometria.

RESULTS

The expression of c-erb B-2 was observed in the carcinomatous area of all 6 cases of MMT (100%), the sarcomatous area of 5 of 6 cases of MMT (83.3%), in 1 of the 6 cases of LMS (16.7%), in all 7 cases of adenocarcinoma (100%), and in all cases of normal epithelial cells (100%), but was not observed in any of the cases of normal stromal cells (0%).

CONCLUSION

The results suggest that the carcinomatous and sarcomatous elements of MMT are similar in their expression of c-erb B-2. MMT differed immunohistochemically from pure sarcoma cells and normal stromal cells, but resembled pure carcinoma cells and normal epithelial cells of the female genital tract.

Quantitative analyses of epidermal growth factor receptors, HER-2/neu oncoprotein and cathepsin D in nonmalignant and malignant uteri

BACKGROUND

Hormone receptors and oncoproteins are receiving increased attention as possible prognostic factors in different carcinomas. Few data are available regarding quantification of their levels of expression in gynecologic malignancies.

METHODS

Epidermal growth factor (EGF) receptor specific binding capacities and affinities were measured by ligand binding assay using [125I]EGF in a competition mode with Accufit software (Lundon Software, Inc., Middlefield, OH). HER-2/neu oncoprotein was extracted from membranes and measured using an enzyme-linked immunosorbent assay. Cathepsin D was measured by an immunoradiometric assay using cytosols for steroid receptor analyses.

RESULTS

EGF receptors in 23 nonmalignant uteri ranged from undetectable to 50 fmol/mg membrane protein (median, 0), with dissociation constant values of 1.2 x 10(-9) M to 8.5 x 10(-10) M, compared with EGF receptors in 76 endometrial cancers that ranged from undetectable to 7674 fmol/mg (median, 52). HER-2/neu oncoprotein ranged from undetectable to 2.9 HER-2/neu units (HNU)/microg protein (median, 0.6) in 41 nonmalignant uteri and from undetectable to 5.8 HNU/microg protein (median, 2.5) in endometrial cancers (n = 53). Cathepsin D ranged from 5 to 32 pmol/mg cytosol protein (median, 11) in 42 nonmalignant uteri and 18 to 144 pmol/mg protein (median, 42) in 29 endometrial cancers.

CONCLUSIONS

Determination of the frequency and levels of EGF receptors, HER-2/neu protein, and cathepsin D in uteri with and without cancer and the availability of reference materials developed in our laboratory, will allow evaluation of their prognostic value in cancers of the uterus.

Overexpression of c-erbB-2 in epithelial ovarian cancer. Prognostic value and relationship with response to chemotherapy

BACKGROUND

Overexpression of the c-erbB-2 protein has been reported in tumors from approximately 25% of patients with epithelial ovarian cancer. However, its clinical significance has not been well established.

METHODS

Overexpression of the c-erbB-2 protein was studied by immunohistochemistry in paraffin-embedded tumor tissue from 106 patients with ovarian cancer.

RESULTS

Tumors from 23 patients (21.7%) had c-erbB-2 overexpression. The percentage of tumors with overexpression was higher in those with Stages III/IV disease (29.2%) compared with those with Stages I/II disease (5.9%) (P = 0.057), in patients with residual tumor greater than 2 cm after initial surgery (37.2%) compared with those with tumor less than 2 cm (9.5%) (P = 0.01), and in patients who failed to respond to chemotherapy with carboplatin and cyclophosphamide (75%) compared with those who responded (18.6%) (P = 0.0043). No correlation was found between c-erbB-2 expression with age, the degree of differentiation, or the histologic subtype. Median survival of the 23 patients with protein overexpression was 62 weeks, whereas 75% of the 83 patients without overexpression were alive at 123 weeks (P = 0.0000). Of the patients with advanced stage disease (III/IV), survival was also lower in those presenting with overexpression (60 weeks) compared with those without expression (75% alive at 93 weeks) (P = 0.0000). Multivariate analysis of possible prognostic factors showed that c-erbB-2 overexpression and residual tumor greater than 2 cm resulted in a worsening of survival rates.

CONCLUSION

c-erbB-2 overexpression in tumors from patients with ovarian cancer resulted in a poorer prognosis than for patients whose tumors did not have overexpression.

Potential criteria for cohort selection in chemoprevention trials of epithelial ovarian cancer

Epithelial ovarian cancer is a heterogeneous disease. Epidemiologic studies have identified risk factors for this disease including advanced age, nulliparity, history of infertility, early age at menarche, late age at menopause, and perhaps ovulation induction. Cohort selection that includes women who have potential precursor lesions and alterations of select biomarkers may prove useful in the design of chemoprevention trials of epithelial ovarian cancer. Nuclear morphometry, specific genetic alterations, and markers of proliferation and differentiation may be useful biomarkers to monitor the efficacy of specific interventions.

Immunohistochemical characterization of undifferentiated carcinomas of the ovary

Immunohistochemical characteristics of undifferentiated carcinomas of the ovary were examined using formalin-fixed, paraffin-embedded tissues with an avidin-biotin staining approach. Eight cases were collected from the pathology files of our Institute from a total of 214 recorded malignant ovarian tumors. For immunostaining, antibodies reacting with epithelial membrane antigen (EMA), pankeratin, vimentin, CA 125, CA 19-9, carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), alpha-1-antitrypsin (AT), epidermal growth factor receptor (EGFR), c-erbB-2, bcl-2 and p53 proteins were used. All the cases examined were positive for EMA and pankeratin, specific markers for epithelial tumors, negative for the non-epithelial tumor marker, vimentin, and also positive for EGFR. Interestingly, only one case was positive for CA 125, despite it being one of the commonest reported indicators of ovarian cancer. CA 19-9 was positive in 7 cases, CEA in 5, AFP in 2, AT in 6 and c-erbB-2 protein in 4. Two cases were positive for p53 protein, and in 1 of these positive staining for bcl-2 was also observed. These results indicate that the epithelial nature is well preserved in undifferentiated ovarian carcinomas, although consistently positive reactions were not observed within the cases for some antigens. They further clearly show that a negative signal for CA 125 can not be considered to exclude the possibility of a primary ovarian tumor.

Immunohistochemical investigation of epidermal growth factor receptor expression in ameloblastomas

Immunohistochemical analysis was performed to determine the localization of epidermal growth factor receptor (EGFR) in ameloblastomas. Ameloblastoma samples were classified into follicular, plexiform, and basal cell types. The number of cases in each category was 17, 19 and 3, respectively. Ameloblastomas, disregarding their histological type, consist of two cell forms: peripheral columnar cells and central stellate cells. The frequency of EGFR expression was much higher in the latter than in the former (P < 0.005). On analysis with respect to histological types, the frequency of EGFR expression in columnar cells was not significantly different between the follicular and the plexiform types, but was observed more frequently in the stellate cells in the follicular than in the plexiform ameloblastomas (P < 0.05). This pattern of EGFR expression was not consistent with the PCNA staining pattern, but was similar to that of keratin expression which we have reported previously. The present study suggests that EGFR expression in ameloblastomas is closely associated with tumour differentiation, and squamous differentiation in particular.

Epidermal growth factor enhances secretion of the ovarian tumor-associated cancer antigen CA125 from the human amnion WISH cell line

OBJECTIVE

We studied the relation between epidermal growth factor (EGF)/epidermal growth factor receptor (EGFR) and CA125 production in WISH cells.

METHODS

We investigated quantitatively and immunohistochemically EGF-stimulated CA125 release from WISH cells and the effect of EGF on CA125 phosphorylation.

RESULTS

Immunohistochemical staining demonstrated that CA125 and EGFR expression on the plasma membrane of the WISH cells was closely correlated with cell density. The WISH cell monolayers (day 4) stained for CA125 in both the cytoplasm and plasma membrane. By day 8, cells began to form clumps in the surrounding monolayer that were positive for membrane-associated CA125 and EGFR, while the monolayer was almost negative for both molecules. Four-day and 8-day cells exposed to EGF demonstrated a loss of both CA125 and EGFR staining. Epidermal growth factor increased the secreted CA125 levels by 50% in day-4 cells but had no effect on day-8 cells. CA125 from WISH cells was phosphorylated, and EGF further enhanced this phosphorylation.

Expression of c-erbB-2 protein and epidermal growth receptor in endometrial carcinomas. Correlation with clinicopathologic and sex steroid receptor status

BACKGROUND

The c-erbB-2 (HER-2/neu) protein is a membrane glycoprotein growth factor receptor showing molecular homology with the epidermal growth factor receptor (EGFR). In endometrial carcinomas, little is known about the relationship between the expression of c-erbB-2 protein and that of EGFR.

METHODS

The immunohistochemical reactivity of monoclonal antibodies against both of these proteins was examined in 34 endometrial carcinomas, and the presence or absence of correlation with the clinicopathologic features or with the immunohistochemical expression of sex steroid receptors (estrogen receptor [ER] and progesterone receptor [PR]) was analyzed.

RESULTS

Of the 34 patients, 22 (64.7%) had c-erbB-2 protein-positive and EGFR-negative tumor, and 8 (23.5%) had tumor positivity for both proteins. Four patients had tumors negative for both proteins. ER or PR positivity was found in 24 (70.6%) of the 34 patients. Intense immunostaining for c-erbB-2 protein was found in 5 (14.7%) of the 34 patients but was not correlated with the stage or grade of differentiation in endometrial carcinoma. However, expression of EGFR in addition to c-erbB-2 protein was more frequently observed with advancing stage of disease and was inversely correlated with the grade of differentiation and with the expression of ER or PR of the tumor.

CONCLUSION

The expression of EGFR, in addition to that of c-erbB-2 protein, is an important event that presumably is linked with progression or with a poorly differentiated state of endometrial carcinomas.