Epidermal growth factor, oestrogen and progesterone receptor expression in primary ovarian cancer: correlation with clinical outcome and response to chemotherapy

Endothelin-1 axes in the framework of predictive, preventive and personalised (3P) medicine

Endothelin-1 (ET-1) is involved in the regulation of a myriad of processes highly relevant for physical and mental well-being; female and male health; in the modulation of senses, pain, stress reactions and drug sensitivity as well as healing processes, amongst others. Shifted ET-1 homeostasis may influence and predict the development and progression of suboptimal health conditions, metabolic impairments with cascading complications, ageing and related pathologies, cardiovascular diseases, neurodegenerative pathologies, aggressive malignancies, modulating, therefore, individual outcomes of both non-communicable and infectious diseases such as COVID-19. This article provides an in-depth analysis of the involvement of ET-1 and related regulatory pathways in physiological and pathophysiological processes and estimates its capacity as a predictor of ageing and related pathologies,a sensor of lifestyle quality and progression of suboptimal health conditions to diseases for their targeted preventionand as a potent target for cost-effective treatments tailored to the person.

Prognostic value of progesterone receptor expression in ovarian cancer: a meta-analysis

Objective

While a prognosis value of progesterone receptor (PR) in ovarian cancer has been reported in some publications, controversial data were presented by different reports. In order to address the disagreement of progesterone receptor in ovarian cancer survival, we conducted this meta-analysis.

Methods

Relevant articles on progesterone receptor and ovarian cancer prognosis were identified via a thorough search of PubMed, Embase and Cochrane Central. Hazard ratios (HR) and 95% confidence interval (CI) were extracted from studies on overall survival (OS) and disease-free survival (DFS)/progress-free survival (PFS)/recurrence-free survival (RFS).

Result

A total of 28 eligible studies containing 5685 patients were collected for analysis. It was found that progesterone receptor positivity was significantly associated with favorable overall survival (OS) (HR = 0.86, 95% CI = 0.78 to 0.95, P = 0.002) and disease-free survival (DFS)/progress-free survival (PFS)/recurrence-free survival (RFS) (HR = 0.75, 95% CI = 0.61 to 0.93, P = 0.008) of ovarian cancer patients. Subgroup analysis showed that progesterone receptor expression was associated with a favorable prognosis of unclassified ovarian cancer, European origin, and immunohistochemical detection method.

Conclusion

Progesterone receptor expression can be used as a favorable prognostic predictor in ovarian cancer managements.

Identification of Ketene-Reactive Intermediate of Erlotinib Possibly Responsible for Inactivation of P450 Enzymes

Erlotinib (ELT), a tyrosine kinase inhibitor, is widely used for the treatment of nonsmall cell lung cancer in clinic. Unfortunately, severe drug-induced liver injury and other adverse effects occurred during the treatment. Meanwhile, ELT has been reported to be a mechanism-based inactivator of cytochrome P450(CYPs) 3A4 and 3A5. The objectives of this study were to identify ketene intermediate of ELT and investigate the association of the acetylenic bioactivation with the enzyme inactivation caused by ELT. A ketene intermediate was detected in human microsomal incubations of ELT, using 4-bromobenzylamine as a trapping agent. CYPs 3A4 and 3A5 mainly contributed to the bioactivation of ELT. Microsomal incubation study showed that the ketene intermediate covalently modified the enzyme protein at lysine residues and destroyed the structure of heme. The vinyl and ethyl analogs of ELT showed minor enzyme inhibitory effect (less than 20%), whereas ELT inactivated more than 60% of the enzyme. The present study provided a novel bioactivation pathway of ELT and facilitated the understanding of the mechanisms of ELT-induced mechanism-based enzyme inactivation and liver injury.

Hormone-receptor expression status of epithelial ovarian cancer in Ibadan, South-western Nigeria

Introduction

Epidemiological evidence strongly suggests that steroid hormones are implicated in the pathogenesis of ovarian cancer. Estrogen receptor (ER) and Progesterone receptor (PR) are prognostic indicators for a number of epithelial tumors and may play the same role in ovarian cancers. This study aims to evaluate the expression of ER and PR in epithelial ovarian cancer (EOC) in an African population and compare it with other prognostic factors such as age, International Federation of Gynaecology and Obstetrics (FIGO) stage, grade and histological subtype.

Methods

Ninety cases of histologically confirmed EOC were reviewed. Immunohistochemistry was used to assess their ER and PR expression status and was then compared with other demographic variables using statistical methods, with level of significance set at p < 0.05.

Results

30.2% and 8.3% of serous and mucinous carcinomas respectively were ER positive while 41.2% and 22.5% of both tumour types were PR positive. One of the two endometrioid carcinomas showed PR expression but neither were positive for ER. The only case of Brenner tumour in the series was ER positive but negative for PR. There was a significant association between ER and the histological subtypes (p = 0.042) while no significant association was found between PR expression and histological subtypes (p = 0.650). No significant association was found between hormone receptor status, age and stage of the EOC.

Conclusion

The study showed a lower ER expression in serous carcinoma compared to large cohorts from developed countries. Future translational studies could be used to determine response of EOC to endocrine therapy.

Correlation between estrogen receptor expression and prognosis in epithelial ovarian cancer: a meta-analysis

OBJECTIVE

Accumulated studies have investigated the prognostic significance of estrogen receptor expression in epithelial ovarian cancer, but results remain controversial. The aim of this study was to perform a meta-analysis to clarify the prognostic value of estrogen receptor expression in epithelial ovarian cancer.

METHODS

A systematic search was performed in PUBMED, EMBASE, and COCHRANE databases to identify relevant studies up to December 2016. The pooled hazard rates (HR) with 95% confidence intervals (CIs) for overall survival and time to tumor progression were calculated and then weighted and pooled in this meta-analysis with a random-effect model.

RESULTS

Thirty-five studies with a total of 5824 patients were included. In brief, the expression of estrogen receptor was associated with an improved overall survival (HR = 0.86, 95% CI = 0.76-0.97), whereas there was no significant difference between estrogen receptor and time to tumor progression among epithelial ovarian cancer patients. Subgroup analysis revealed that estrogen receptor expression was significantly correlated with overall survival in different subgroups, such as in unclassified epithelial ovarian cancer (HR= 0.80, 95% CI = 0.66-0.95), studies using immunohistochemistry detection method (HR= 0.85, 95% CI = 0.73-1.00), European population (HR= 0.75, 95% CI = 0.60-0.94) and estrogen receptor α subtype (HR= 0.78, 95% CI = 0.62-0.98).

CONCLUSIONS

Estrogen receptor, especially estrogen receptor α, was associated with an improved overall survival in epithelial ovarian cancer. Estrogen receptor expression may be a promising prognostic factor in epithelial ovarian cancer patients.

Effect of estrogen receptor β agonists on proliferation and gene expression of ovarian cancer cells

Background

Estrogen receptor (ER) β has been suggested to affect ovarian carcinogenesis. We examined the effects of four ERβ agonists on proliferation and gene expression of two ovarian cancer cell lines.

Methods

OVCAR-3 and OAW-42 ovarian cancer cells were treated with the ERβ agonists ERB-041, WAY200070, Liquiritigenin and 3β-Adiol and cell growth was measured by means of the Cell Titer Blue Assay (Promega). ERβ expression was knocked down by transfection with specific siRNA. Additionally, transcriptome analyses were performed by means of Affymetrix GeneChip arrays. To confirm the results of DNA microarray analysis, Western blot experiments were performed.

Results

All ERβ agonists tested significantly decreased proliferation of OVCAR-3 and OAW-42 cells at a concentration of 10 nM. Maximum antiproliferative effects were induced by flavonoid Liquiritigenin, which inhibited growth of OVCAR-3 cells by 31.2% after 5 days of treatment, and ERB-041 suppressing proliferation of the same cell line by 29.1%. In OAW-42 cells, maximum effects were observed after treatment with the ERβ agonist WAY200070, inhibiting cell growth by 26.8%, whereas ERB-041 decreased proliferation by 24.4%. In turn, knockdown of ERβ with specific siRNA increased cell growth of OAW-42 cells about 1.9-fold. Transcriptome analyses revealed a set of genes regulated by ERβ agonists including ND6, LCN1 and PTCH2, providing possible molecular mechanisms underlying the observed antiproliferative effects.

Conclusion

In conclusion, the observed growth-inhibitory effects of all ERβ agonists on ovarian cancer cell lines in vitro encourage further studies to test their possible use in the clinical setting.

The role of reproductive hormones in epithelial ovarian carcinogenesis

Epithelial ovarian cancer comprises ∼85% of all ovarian cancer cases. Despite acceptance regarding the influence of reproductive hormones on ovarian cancer risk and considerable advances in the understanding of epithelial ovarian carcinogenesis on a molecular level, complete understanding of the biologic processes underlying malignant transformation of ovarian surface epithelium is lacking. Various hypotheses have been proposed over the past several decades to explain the etiology of the disease. The role of reproductive hormones in epithelial ovarian carcinogenesis remains a key topic of research. Primary questions in the field of ovarian cancer biology center on its developmental cell of origin, the positive and negative effects of each class of hormones on ovarian cancer initiation and progression, and the role of the immune system in the ovarian cancer microenvironment. The development of the female reproductive tract is dictated by the hormonal milieu during embryogenesis. Intensive research efforts have revealed that ovarian cancer is a heterogenous disease that may develop from multiple extra-ovarian tissues, including both Müllerian (fallopian tubes, endometrium) and non-Müllerian structures (gastrointestinal tissue), contributing to its heterogeneity and distinct histologic subtypes. The mechanism underlying ovarian localization, however, remains unclear. Here, we discuss the role of reproductive hormones in influencing the immune system and tipping the balance against or in favor of developing ovarian cancer. We comment on animal models that are critical for experimentally validating existing hypotheses in key areas of endocrine research and useful for preclinical drug development. Finally, we address emerging therapeutic trends directed against ovarian cancer.

Functional characterization of epithelial ovarian cancer histotypes by drug target based protein signaling activation mapping: implications for personalized cancer therapy

Epithelial ovarian carcinoma (EOC) is a deadly disease, with a 5-year survival of 30%. The aim of the study was to perform broad-scale protein signaling activation mapping to evaluate if EOC can be redefined based on activated protein signaling network architecture rather than histology. Tumor cells were isolated using laser capture microdissection (LCM) from 72 EOCs. Tumors were classified as serous (n = 38), endometrioid (n = 13), mixed (n = 8), clear cell (CCC; n = 7), and others (n = 6). LCM tumor cells were lysed and subjected to reverse-phase protein microarray to measure the expression/activation level of 117 protein drug targets. Unsupervised hierarchical clustering analysis was utilized to explore the overall signaling network. ANOVA was used to detect significant differences among the groups (p < 0.05). Regardless of histology, unsupervised analysis revealed five pathway-driven clusters. When the EOC histotypes were compared by ANOVA, only CCC showed a distinct signaling network, with activation of EGFR, Syk, HER2/ErbB2, and SHP2 (p = 0.0007, p = 0.0021, p < 0.0001, and p = 0.0410, respectively). The histological classification of EOC fails to adequately describe the underpinning protein signaling network. Nevertheless, CCC presents unique signaling characteristics compared to the other histotypes. EOC may need to be characterized by functional signaling activation mapping rather than pure histology.

IL6 induces TAM resistance via kinase-specific phosphorylation of ERα in OVCA cells

About 40-60% of ovarian cancer (OVCA) cases express ERα, but only a small proportion of patients respond clinically to anti-estrogen treatment with estrogen receptor (ER) antagonist tamoxifen (TAM). The mechanism of TAM resistance in the course of OVCA progression remains unclear. However, IL6 plays a critical role in the development and progression of OVCA. Our recent results indicated that IL6 secreted by OVCA cells may promote the resistance of these cells to TAM via ER isoforms and steroid hormone receptor coactivator-1. Here we demonstrate that both exogenous (a relatively short period of treatment with recombinant IL6) and endogenous IL6 (generated as a result of transfection with a plasmid encoding sense IL6) increases expression of pERα-Ser118 and pERα-Ser167 in non-IL6-expressing A2780 cells, while deleting endogenous IL6 expression in IL6-overexpressing CAOV-3 cells (by transfection with a plasmid encoding antisense IL6) reduces expression of pERα-Ser118 and pERα-Ser167, indicating that IL6-induced TAM resistance may also be associated with increased expression of pERα-Ser118 and pERα-Ser167 in OVCA cells. Results of further investigation indicate that IL6 phosphorylates ERα at Ser118 and Ser167 by triggering activation of MEK/ERK and phosphotidylinositol 3 kinase/Akt signaling, respectively, to activate the ER pathway and thereby induce OVCA cells resistance to TAM. These results indicate that IL6 secreted by OVCA cells may also contribute to the refractoriness of these cells to TAM via the crosstalk between ER and IL6-mediated intracellular signal transduction cascades. Overexpression of IL6 not only plays an important role in OVCA progression but also promotes TAM resistance. Our results indicate that TAM-IL6-targeted adjunctive therapy may lead to a more effective intervention than TAM alone.

Estrogen signaling crosstalk: Implications for endocrine resistance in ovarian cancer

Resistance to anti-estrogen therapies is a prominent challenge in the treatment of ovarian cancer. Tumors develop endocrine resistance by acquiring adaptations that help them rely on alternative oncogenic signaling cascades, which crosstalk with estrogen signaling pathways. An understanding of estrogen signaling crosstalk with these growth promoting cascades is essential in order to maximize efficacy of anti-estrogen treatments in ovarian cancer. Herein, we provide an overview of estrogen signaling in ovarian cancer and discuss the major challenges associated with anti-estrogen therapies. We also review what is currently known about how genomic and non-genomic estrogen signaling pathways crosstalk with several major oncogenic signaling cascades. The insights provided here illustrate existing strategies for targeting endocrine resistant ovarian tumors and may help identify new strategies to improve the treatment of this disease.

Autocrine production of interleukin-6 confers ovarian cancer cells resistance to tamoxifen via ER isoforms and SRC-1

Although 40-60% of ovarian cancer (OVCA)s express estrogen receptor (ER)α, only a minor proportion of patients respond to anti-estrogen treatment with ER antagonist tamoxifen (TAM). The mechanism underlying TAM resistance in the course of OVCA progression is incompletely understood. However, interleukin-6 (IL-6) plays a critical role in the development and progression of OVCA. Here we explore an association between IL-6 and TAM resistance. We demonstrate that both exogenous (a relatively short period of treatment with recombinant IL-6) and endogenous IL-6 (by transfecting with plasmid encoding for sense IL-6) induce TAM resistance in non-IL-6-expressing A2780 cells, while deleting of endogenous IL-6 expression in IL-6-overexpressing CAOV-3 cells (by transfecting with plasmid encoding for antisense IL-6) promotes the sensitivity of these cells to TAM. Further investigation indicates that TAM resistance caused by IL-6 is associated with the alteration of ERα, ERβ and steroid hormone receptor coactivator (SRC)-1 expression levels, the protein interactions between SRC-1 and ERα, but not ERβ, as well as blockage of estrogen-induced ER receptor nuclear translocation. These results show that IL-6 secreted by OVCA cells may contribute to the refractoriness of these cells to TAM via ER isoforms and SRC-1. Overexpression of IL-6 not only plays an important role in OVCA progression but also contributes to TAM resistance. Our studies suggest that TAM-IL-6-targeted adjunctive therapy may lead to a more effective intervention than TAM alone.

Addition of vandetanib to pegylated liposomal doxorubicin (PLD) in patients with recurrent ovarian cancer. A randomized phase I/II study of the AGO Study Group (AGO-OVAR 2.13)

BACKGROUND

PLD is a standard treatment in patients with recurrent platinum-resistant or refractory ovarian cancer. Vandetanib is an oral once daily administered inhibitor of VEGFR-, EGFR- and RET-signaling with activity in combination with chemotherapy in some solid tumours. We aimed to establish a feasible combination therapy of PLD and vandetanib in ovarian cancer.

METHODS

Eligible patients were treated with PLD 50 mg/m(2) q28 and vandetanib 100 mg/d po. It was planned to recruit at least 10 patients evaluable for toxicity over 2 treatment cycles. Primary endpoints were tolerability and safety; secondary endpoint was efficacy.

RESULTS

Fourteen of 15 registered patients started treatment and were evaluable for toxicity. Three patients (21%) stopped after first cycle (PD, withdrawal of consent, nausea/vomiting). The remaining 11 patients were treated for at least 2 cycles. Dose reductions of PLD and vandetanib were indicated in 4 (29%) and 5 patients (36%), respectively. The following G3/4 toxicities occurred per patient: 2 (14%) elevated liver enzymes G3, 2 (14%) neutropenia G3/4, 5 (36%) PPE G3/4, 2 (14%) mucositis G3. Tyrosine kinase inhibitor attributed side effects like hypertension or bowel perforations were not reported. Toxicity led to cessation of treatment in 4 patients (29%). Ten patients were evaluable for response: PR 1, SD 4. The median PFS was 6.7 months and median OS was 11.1 months.

CONCLUSIONS

The combination of PLD 50 mg/m(2)q28 and vandetanib 100 mg/d is feasible, but may be intolerable due to reported toxicity.

Prognostic role of hormone receptors in ovarian cancer: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to summarize the global predicting role of hormone receptors for survival in ovarian cancer.

METHODS

Eligible studies were identified and assessed for quality through multiple search strategies. Data were collected from studies comparing overall or progression-free/disease-free/relapse-free survival in patients with elevated levels of estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor 2 (HER2) with those in patients with lower levels. Studies were pooled, and combined hazards ratios (HRs) of ER, PR, and HER2 for survival were calculated, respectively.

RESULTS

A total of 35 studies were included for meta-analysis (23 for ER, 19 for PR, and 8 for HER2). For overall survival, the pooled HR of PR reached 0.88 [95% confidence interval (CI), 0.82-0.95], which means that elevated PR level could significantly indicate better survival. In contrast, elevated levels of HER2 could predict worse outcome with an HR of 1.41 (95% CI, 1.05-1.89). Increased level of ER was not significantly prognostic (HR, 0.94; 95% CI, 0.87-1.01). For progression-free survival/disease-free survival/recurrence-free survival, elevated PR level also had predictive value for better outcome with a pooled HR of PR of 0.80 (95% CI, 0.67-0.95). Oppositely, elevated HER2 level could predict poorer outcome with an HR of 1.55 (95% CI, 1.11-2.16). Estrogen receptor failed to predict outcome with an HR of 0.90 (95% CI, 0.78-1.03).

CONCLUSIONS

In patients with ovarian cancer, elevated level of PR predicted favorable survival, and elevated level of HER2 was associated with worse survival.

Hormone response in ovarian cancer: time to reconsider as a clinical target?

Ovarian cancer is the sixth most common cancer worldwide among women in developed countries and the most lethal of all gynecologic malignancies. There is a critical need for the introduction of targeted therapies to improve outcome. Epidemiological evidence suggests a critical role for steroid hormones in ovarian tumorigenesis. There is also increasing evidence from in vitro studies that estrogen, progestin, and androgen regulate proliferation and invasion of epithelial ovarian cancer cells. Limited clinical trials have shown modest response rates; however, they have consistently identified a small subset of patients that respond very well to endocrine therapy with few side effects. We propose that it is timely to perform additional well-designed trials that should include biomarkers of response.

Hormone response in ovarian cancer: time to reconsider as a clinical target?

Ovarian cancer is the sixth most common cancer worldwide among women in developed countries and the most lethal of all gynecologic malignancies. There is a critical need for the introduction of targeted therapies to improve outcome. Epidemiological evidence suggests a critical role for steroid hormones in ovarian tumorigenesis. There is also increasing evidence from in vitro studies that estrogen, progestin, and androgen regulate proliferation and invasion of epithelial ovarian cancer cells. Limited clinical trials have shown modest response rates; however, they have consistently identified a small subset of patients that respond very well to endocrine therapy with few side effects. We propose that it is timely to perform additional well-designed trials that should include biomarkers of response.

The G protein-coupled estrogen receptor 1 (GPER/GPR30) does not predict survival in patients with ovarian cancer

Background

Even though ovarian tumors are not generally considered estrogen-sensitive, estrogens may still have an impact on ovarian tumor progression. The recently identified trans-membrane estrogen receptor GPER is involved in rapid estrogen signaling. Furthermore, it binds selective estrogen receptor modulators with agonistic effect, which could explain tamoxifen controversies.

Methods

GPER mRNA was assayed with quantitative real-time PCR (qPCR) in 42 primary ovarian tumors and 7 ovarian cancer cell lines. ERα and ERβ mRNA were analyzed for comparison. GPER protein was semi-quantified with densitometric scanning of Western blots and its tissue distribution analyzed with immunohistochemistry (IHC) in 40 ovarian tumors. In addition, IHC was evaluated in a tissue microarray (TMA) of 150 primary malignant ovarian tumors.

Results

All tumor samples contained GPER mRNA. The content of mRNA was not different between benign and malignant tumors, but one third of malignant samples over-expressed GPER mRNA. The content of ERα mRNA was higher in malignant than in benign tumors, whereas ERβ mRNA was higher in benign than in malignant tumors. GPER mRNA was detected in all seven ovarian cancer cell lines with highest levels in TOV21G and TOV112D cells. Similar expression pattern was seen for ERβ mRNA. Western blot demonstrated GPER protein in all tumor samples. Semi-quantification showed no difference between benign and malignant tumors, but about one third of malignant samples over-expressed GPER protein. GPER staining was localized mainly in epithelial cells. In the TMA study we found no correlation between GPER staining and clinical stage, histological grade or patient survival.

Conclusions

GPER mRNA as well as GPER protein is present in both benign and malignant ovarian tumor tissue. About one third of malignant tumors over-expressed both GPER mRNA and protein. This, however, correlated neither with histological or clinical parameters nor with patient survival.

EGFR(s) in aging and carcinogenesis of the gastrointestinal tract

Cells of the gastrointestinal (GI) mucosa are subject to a constant process of renewal which, in normal adults, reflects a balance between the rates of cell production and cell loss. Detailed knowledge of these events is, therefore, essential for a better understanding of the normal aging processes as well as many GI diseases, particularly malignancy, that represent disorders of tissue growth. In general, many GI dysfunctions, including malignancy, increase with advancing age, and aging itself is associated with alterations in structural and functional integrity of the GI tract. Although the regulatory mechanisms for age-related increase in the incidence of GI-cancers are yet to be fully delineated, recent evidence suggests a role for epidermal growth family receptors and its family members {referred to as EGFR(s)} in the development and progression of carcinogenesis during aging. The present communication discusses the involvement of EGFR(s) in regulating events of GI cancers during advancing age and summarizes the current available therapeutics targeting these receptors. The current review also describes the effectiveness of ErbB inhibitors as well as combination therapies. Additionally, the involvement of GI stem cells in the development of the age-related rise in GI cancers is emphasized.

Predictive and prognostic protein biomarkers in epithelial ovarian cancer: recommendation for future studies

Epithelial ovarian cancer is the most lethal gynecological malignancy. Due to its lack of symptoms, this disease is diagnosed at an advanced stage when the cancer has already spread to secondary sites. While initial rates of response to first treatment is >80%, the overall survival rate of patients is extremely low, mainly due to development of drug resistance. To date, there are no reliable clinical factors that can properly stratify patients for suitable chemotherapy strategies. Clinical parameters such as disease stage, tumor grade and residual disease, although helpful in the management of patients after their initial surgery to establish the first line of treatment, are not efficient enough. Accordingly, reliable markers that are independent and complementary to clinical parameters are needed for a better management of these patients. For several years, efforts to identify prognostic factors have focused on molecular markers, with a large number having been investigated. This review aims to present a summary of the recent advances in the identification of molecular biomarkers in ovarian cancer patient tissues, as well as an overview of the need and importance of molecular markers for personalized medicine in ovarian cancer.

Expression of p16 protein and epidermal growth factor receptor in patients with adenocarcinoma of the uterine cervix: an immunohistochemical analysis

OBJECTIVE

The present study assessed the expression of p16 and epidermal growth factor receptor (EGFR) in patients with adenocarcinoma of the uterine cervix to determine their influence on prognosis and to evaluate a possible association between their expression and various clinicopathologic parameters.

METHODS

p16 and EGFR expression was investigated by immunohistochemistry from paraffin-embedded tissue in 39 patients with adenocarcinoma of the uterine cervix. The immunohistochemical findings were correlated with different clinicopathologic parameters of the patients.

RESULTS

p16 was expressed in 56% of the patients. A trend towards increased lymph vascular space invasion was observed in p16 positive tumors (p = 0.06). There was no statistically significant association between p16 expression and clinical stage, age, histology, tumor size, tumor grade, lymph node status and recurrence disease (p > 0.05). p16 expression did influence neither disease-free nor overall survival (p > 0.05). EGFR was expressed in 44% of the patients. There was no statistically significant correlation between EGFR expression and clinical stage, age, histology, tumor size, tumor grade, lymph vascular space invasion, lymph node status and recurrence disease (p > 0.05). EGFR expression did influence neither disease-free nor overall survival (p > 0.05).

CONCLUSION

p16 and EGFR are frequently expressed in adenocarcinoma of the uterine cervix. Our study observed a trend towards increased lymph vascular space invasion in p16 positive tumors. Otherwise, the expression of the investigated parameters did not correlate with any clinicopathologic parameters and had no influence on overall and disease-free survival. So far, the investigation of p16 and EGFR is of limited use to assess patients' prognosis and guide clinical management.

RSK in tumorigenesis: connections to steroid signaling

The Ser/Thr kinase family, RSK, has been implicated in numerous types of hormone-dependent and -independent cancers. However, there has been little consideration of RSKs as downstream mediators of steroid hormone non-genomic effects or of their ability to facilitate steroid receptor-mediated gene expression. Steroid hormone signaling can directly stimulate the MEK/ERK/RSK pathway to regulate cellular proliferation and survival in transformed cells. To date, multiple mechanisms of RSK and steroid hormone receptor-mediated proliferation/survival have been elucidated. For example, RSK enhances proliferation of breast and prostate cancer cells via its ability to control the levels of the estrogen receptor co-activator, cyclin D1. While in lung and other tumors RSK may control apoptosis via estrogen-mediated regulation of mitochondrial integrity. Thus the RSKs could be important anti-cancer therapeutic targets in many different transformed tissues. The recent discovery of RSK-specific inhibitors will advance our current understanding of RSK in transformation and drive these studies into animal and clinical models. In this review we explore the mechanisms associated with RSK in tumorigenesis and their relationship to steroid hormone signaling.

Modest effect of p53, EGFR and HER-2/neu on prognosis in epithelial ovarian cancer: a meta-analysis

BACKGROUND

P53, EGFR and HER-2/neu are the most frequently studied molecular biological parameters in epithelial ovarian cancer, but their prognostic impact is still unequivocal. We performed a meta-analysis to more precisely estimate their prognostic significance.

METHODS

Published studies that investigated the association between p53, EGFR and HER-2/neu status and survival were identified. Meta-analysis was performed using a DerSimonian-Laird model. Publication bias was investigated using funnel plots and sources of heterogeneity were identified using meta-regression analysis.

RESULTS

A total of 62 studies were included for p53, 15 for EGFR and 20 for HER-2/neu. P53, EGFR and HER-2/neu status had a modest effect on overall survival (pooled HR 1.47, 95% CI 1.33-1.61 for p53; HR 1.65, 95% CI 1.25-2.19 for EGFR and HR 1.67, 95% CI 1.34-2.08 for HER-2/neu). Meta-regression analysis for p53 showed that FIGO stage distribution influenced study outcome. For EGFR and HER-2/neu, considerable publication bias was present.

CONCLUSIONS

Although p53, EGFR and HER-2/neu status modestly influences survival, these markers are, by themselves, unlikely to be useful as prognostic markers in clinical practice. Our study highlights the need for well-defined, prospective clinical trials and more complete reporting of results of prognostic factor studies.

GPR30 predicts poor survival for ovarian cancer

OBJECTIVES

GPR30 is a 7-transmembrane G protein-coupled estrogen receptor that functions alongside traditional estrogen receptors to regulate cellular responses to estrogen. Recent studies suggest that GPR30 expression is linked to lower survival rates in endometrial and breast cancer. This study was conducted to evaluate GPR30 expression in ovarian tumors.

METHODS

GPR30 expression was analyzed using immunohistochemistry and archival specimens from 45 patients with ovarian tumors of low malignant potential (LMP) and 89 patients with epithelial ovarian cancer (EOC). Expression, defined as above or below the median (intensity times the percentage of positive epithelial cells) was correlated with predictors of adverse outcome and survival.

RESULTS

GPR30 expression above the median was observed more frequently in EOC than in LMP tumors (48.3% vs. 20%, p=0.002), and in EOC was associated with lower 5-year survival rates (44.2% vs. 82.6%, Log-rank p<0.001). Tumor grade and FIGO stage, the other significant predictors of survival, were used to stratify cases into "high risk" and "low risk" groups. The 5-year survival rate for "low risk" EOC (all grade 1 and Stage I/II, grade 2) was 100%. In "high risk" EOC (all grade 3 and Stage III/IV, grade 2), the difference in 5-year survival by GPR 30 expression was significant (33.3% vs. 72.4%, p=0.001).

CONCLUSIONS

The novel estrogen-responsive receptor GPR30 is preferentially expressed in "high risk" EOC and is associated with lower survival rates. Further investigation of GPR30 as a potential target for therapeutic intervention in high risk EOC is warranted.

Estradiol attenuates EGF-induced rapid uPAR mobilization and cell migration via the G-protein-coupled receptor 30 in ovarian cancer cells

Epidermal growth factor (EGF) stimulates proliferation and migration in ovarian cancer cells, and high tumor expression of the EGF system correlates with poor prognosis. Epidermal growth factor upregulates urokinase plasminogen activator receptor (uPAR) on the cell surface via 3 distinct mechanisms: rapid mobilization of uPAR from detergent-resistant domains, increased mRNA, and decreased degradation. G-protein-coupled receptor 30 (GPR30) is a newly identified membrane estrogen receptor (ER).The objective of this study was to explore the effects of 17beta-estradiol (E(2)) on uPAR expression and cell migration in ovarian cancer cells and further to identify the ER involved.We used 7 ovarian cancer cell lines, cell migration assay, cellular binding of (125)I-uPA, cellular degradation of (125)I-uPA/PAI-1 complex, enzyme-linked immunosorbent assay for uPAR, solid-phase enzyme immunoassay for ERalpha, and quantitative polymerase chain reaction. Estradiol attenuates the stimulatory effect of EGF on cell migration and uPAR expression. Specifically, E(2) reduces the very rapid increase of detergent extractable uPAR, which occurs within minutes of EGF stimulation and probably represents mobilization of uPAR from detergent-resistant domains such as lipid rafts. Estradiol influenced neither the amount of uPAR mRNA nor the rate of uPAR degradation or solubilization. The nuclear ER antagonists ICI 182780 and tamoxifen, which are GPR30 agonists, as well as the specifically constructed GPR30 agonist G1, mimicked the effect of E(2) on uPAR expression and cell migration. OVCAR-3 cells express mRNA for GPR30.Estradiol attenuates EGF-induced mobilization of ligated uPAR from detergent-resistant domains and subsequent migration in ovarian cancer cells. The response to various ER ligands indicates that this effect is mediated via the membrane ER GPR30.

Loss of estrogen receptor beta isoform expression and its correlation with aberrant DNA methylation of the 5'-untranslated region in human epithelial ovarian carcinoma

Evidence exists that sex steroids such as estrogens affect epithelial ovarian cancer. The expression profiles of the estrogen receptors (ER) and ERbeta in particular have not been fully described. Therefore, in our present study, we examined the methylation status of the promoters 0K and 0N, and the expression of ERbeta isoforms in human epithelial ovarian carcinoma. We then correlated methylation status with ER expression status. Twelve ovarian carcinoma cell lines, six primary cultures of ovarian surface epithelial cells (OSE), and 64 cases of ovarian carcinoma tissues were examined. Bisulfite sequencing and quantitative reverse transcription-polymerase chain reaction were used to evaluate methylation status and expression of ERbeta isoforms. The relative abundance of exon 0N, ERbeta1, ERbeta2, and ERbeta4 mRNA was significantly lower in ovarian cancer cell lines and tissues than in their corresponding normal counterparts. However, ERbeta5 mRNA level was relatively higher in the cancers, in clear cell adenocarcinoma in particular, than in the normal ovary. Bisulfite sequencing analysis demonstrated that the two promoters of the ERbeta gene exhibited distinct methylation patterns. Promoter 0N was unmethylated in OSE, rarely methylated in normal ovarian tissues, and extensively methylated in ovarian cancer cell lines and tissues (11/15 cell lines and 18/32 cancer tissues were extensively methylated). The promoter 0K was, however, unmethylated in both normal and malignant ovarian cells and tissues. A significant correlation between promoter 0N hypermethylation and the loss of exon 0N, ERbeta1, ERbeta2, and ERbeta4 mRNA expression was detected in ovarian carcinoma cells and tissues. Treatment of ovarian carcinoma cells with 5-aza-2' deoxycytidine resulted in reexpression of the ERbeta gene. The results of our present study suggest that ERbeta is inactivated mainly through aberrant DNA methylation. This process may play an important role in the pathogenesis of epithelial ovarian cancer.

A phase I study of lapatinib in combination with carboplatin in women with platinum sensitive recurrent ovarian carcinoma

OBJECTIVES

To determine the maximum tolerated dose (MTD), spectrum of toxicities, clinical activity, and pharmacokinetics of carboplatin given in combination with lapatinib in women with a first recurrence of platinum sensitive epithelial ovarian carcinoma.

METHODS

Patients with measurable, platinum sensitive recurrent epithelial ovarian carcinoma were eligible. Cohorts of 3-6 patients were to receive up to 6 cycles of intravenous carboplatin AUC of 6 every 21 days in combination with escalating dosages of oral lapatinib (starting at a dose of 750 mg daily). Toxicity was assessed using NCI CTC for Adverse Events. Clinical response was monitored using RECIST criteria. Pharmacokinetic (PK) analysis was performed for the second cohort of patients.

RESULTS

Twelve patients were enrolled. No dose limiting toxicity was noted. Two of 6 patients in the first cohort had unanticipated excessive delays in treatment due to non-dose limiting G3 neutropenia. Therefore, the study was modified to reduce the carboplatin dose in the second cohort. The median number of courses administered to the 11 evaluable patients in these two cohorts was 2.8 (range 1-6). Drug-related grade 3 or 4 toxicities included non-dose limiting G4 thrombocytopenia (n=1), and non-dose limiting G3 neutropenia (n=3). Of the 11 patients who received >or=1 course of therapy, 3 (27%) had a partial response, and 3 (27%) had stable disease. The pharmacokinetics of carboplatin were not significantly altered by concomitant administration of lapatinib.

CONCLUSIONS

This regimen of lapatinib and carboplatin was associated with unacceptable non-dose limiting toxicities, excessive treatment delays and limited clinical responses.

Combined targeting of endothelin A receptor and epidermal growth factor receptor in ovarian cancer shows enhanced antitumor activity

Ovarian carcinomas overexpress endothelin A receptors (ET(A)R) and epidermal growth factor (EGF) receptor (EGFR). In these cells, endothelin-1 (ET-1) triggers mitogenic and invasive signaling pathways that are in part mediated by EGFR transactivation. Combined targeting of ET(A)R, by the specific ET(A)R antagonist ZD4054, and of EGFR by the EGFR inhibitor gefitinib (IRESSA), may offer improvements in ovarian carcinoma treatment. In HEY and OVCA 433 ovarian carcinoma cells, ET-1 or EGF induced rapid activation of EGFR, p42/44 mitogen-activated protein kinase (MAPK), and AKT. ZD4054 was able to reduce the ET-1-induced EGFR transactivation. Gefitinib significantly inhibited EGF- and ET-1-induced EGFR phosphorylation, but incompletely reduced the ET-1-induced activation of downstream targets. ZD4054 plus gefitinib resulted in a greater inhibition of EGFR, MAPK, and AKT phosphorylation, indicating the critical role of these interconnected signaling proteins. ZD4054 effectively inhibited cell proliferation, invasiveness, and vascular endothelial growth factor (VEGF) secretion. Concomitantly, ZD4054 enhanced apoptosis and E-cadherin promoter activity and expression. In both cell lines, the drug combination resulted in a significant decrease in cell proliferation (65%), invasion (52%), and VEGF production (50%), accompanied by a 2-fold increase in apoptosis. The coadministration of ZD4054 enhanced the efficacy of gefitinib leading to partial (82%) or complete tumor regression on HEY ovarian carcinoma xenografts. Antitumor effects were paralleled by biochemical and immunohistologic evidence of decreased vascularization, Ki-67, matrix metalloproteinase-2 (MMP-2), VEGF, MAPK and EGFR, and enhanced E-cadherin expression. The cross-signaling between the EGFR/ET(A)R pathways provides a rationale to combine EGFR inhibitors with ET(A)R antagonists, identifying new effective therapeutic opportunities for ovarian cancer.

Ovarian cancer survival and polymorphisms in hormone and DNA repair pathway genes

We evaluated the association between 21 polymorphisms in hormone and DNA repair pathway genes and survival among 454 Australian women diagnosed with invasive epithelial ovarian cancer. The cohort was followed for mortality using personal identifiers which were linked to state cancer registry records and the Australian National Death Index. The mean follow-up time after ovarian cancer diagnosis was 4.63 years (all women) and 8.07 years for the censored group (those alive or dead from non-ovarian cancer causes). Two hundred and eighty-eight (63%) ovarian cancer deaths occurred during the follow-up period. No association was observed for the vast majority of polymorphisms, but there was suggestive evidence for altered risk of ovarian cancer death associated with the CYP17 5'UTR C allele (HR 1.30; 95% CI=1.02-1.68, p= 0.04), and for the SRD5A2 V89L C allele (HR 0.79; 95% CI=0.62-1.01, p=0.06). These results are interesting given tentative evidence that both of these variants are also associated with increased predisposition to ovarian cancer in our extended Australian study, and in other published studies. However, given the marginal significance of these associations and the large number of tests performed, independent replication will be necessary to validate these novel findings.

Phase I Clinical and Pharmacodynamic Evaluation of Oral CI-1033 in Patients with Refractory Cancer

PURPOSE

To determine the tolerability and pharmacokinetics of CI-1033 given daily for 7 days of a 21-day cycle. Tumor response and changes in erbB receptor tyrosine kinase activity in tumor and skin tissue were examined, and modulation of potential biomarkers in plasma was explored.

DESIGN

This was a dose-finding phase I study in patients with advanced solid malignancies. Patients were evaluated for safety, pharmacokinetics, and tumor response. Pharmacodynamic markers, such as Ki67, p27, and erbB receptor status, were assessed in tumor and skin tissue using immunohistochemical and immunoprecipitation methodologies. Plasma biomarkers HER2, vascular endothelial growth factor, interleukin-8, and matrix metalloproteinase-9 were evaluated using immunologic techniques.

RESULTS

Fifty-three patients were enrolled in the study. Dose-limiting toxicity (emesis, persistent rash, and mouth ulcer) was observed at 750 mg. The maximum tolerated dose was 650 mg. There were no confirmed objective responses. CI-1033 treatment showed down-regulation of epidermal growth factor receptor, HER2, and Ki67 in a variety of tumor tissues and up regulation of p27 in skin tissue. Plasma HER2 was reduced following CI-1033 administration, but no consistent change in vascular endothelial growth factor, interleukin-8, or matrix metalloproteinase-9 was noted. CI-1033 plasma concentrations were proportional to dose.

CONCLUSION

The safety and pharmacokinetic profile of CI-1033 was favorable for multidose oral administration. Evidence of modulation of erbB receptor activity in tumor and skin tissue was accompanied by changes in markers of proliferation and cell cycle inhibition. Additional clinical trials are warranted in defining the role of CI-1033 in the treatment of cancer and further assessing the utility of antitumor markers.

Epidermal growth factor receptor is a critical mediator of ultraviolet B irradiation-induced signal transduction in immortalized human keratinocyte HaCaT cells

Epidermal growth factor receptor (EGFR) is a critical mediator of several types of epithelial cancers. Skin cancer arising from exposure to ultraviolet B irradiation (UVB) from the sun is a prominent form of human cancer. Recent data indicate that in addition to cognate ligands, EGFR is activated by UVB irradiation. We used pharmacological and genetic approaches to investigate the function of EGFR in mediating UVB-induced signal transduction in human skin keratinocyte HaCaT cells. Pharmacological inhibition of EGFR tyrosine kinase significantly inhibited UVB-mediated induction of ERK, p38, and JNK MAP kinases, and their effectors, transcription factors c-Fos and c-Jun. Inhibition of UVB activation of EGFR also suppressed activation of AKT-, PKC-, and PKA-dependent signal transduction pathways. B82 mouse L cells devoid of EGFR were used to further investigate EGFR dependence of UVB-induced signal transduction. UVB failed to induce ERK, and JNK activation was reduced 60% in B82 cells compared to B82K+ cells, which express EGFR. In addition, UVB induced both c-Fos and c-Jun proteins in B82K+ cells, whereas neither were induced in B82 cells. Taken together, these data demonstrate that EGFR is required for UVB-mediated induction of multiple signaling pathways that are known to mediate tumor formation in skin.

Receptor tyrosine kinase (RTK) inhibition is effective in chemosensitising EGFR-expressing drug resistant human ovarian cancer cell lines when used in combination with cytotoxic agents

This study has focused on the use of RTK inhibitors in the treatment of ovarian cancer. We have used the human ovarian cancer cell line PEO1 alongside two in-house derived drug resistant variants: PEO1CarboR (8-fold acquired resistance to carboplatin and cisplatin) and the Pgp expressing PEO1TaxR (15-fold acquired resistance to paclitaxel). These variant cell lines were shown to have a higher expression of EGFR 1.6- and 2.0-fold increase, respectively, compared with the parental cell line. We have shown that the RTK inhibitor GW282974A (an analogue of GW2016; lapatinib) is effective in chemosensitisation of drug resistant EGFR over-expressing cells giving rise to a synergistic effect when used in combination with either cisplatin or paclitaxel in chemosensitivity assays. These effects were also seen at the level of apoptosis using the Annexin V assay and expression levels of the IAP Survivin. A reduction in the downstream signalling effector phosphorylated ERK was seen in both resistant cell lines when GW282974A was used in combination with either cisplatin or paclitaxel. This reduction was not so apparent in cells treated with the single agent GW282974A or cytotoxic agent. Interestingly, we did not show evidence for an enhanced sensitivity to the RTK inhibitor in our EGFR expressing resistant lines versus parental PEO1 cells. However, the paclitaxel resistant cell line appeared more sensitive to the chemosensitising effects of GW282974A, in line with its increased EGFR expression. Our data suggest that RTK inhibition is effective in circumvention of tumour cell drug resistance that occurs in conjunction with EGFR overexpression.

Increased Bioavailability of Intravenous Versus Oral CI-1033, a Pan erbB Tyrosine Kinase Inhibitor: Results of a Phase I Pharmacokinetic Study

PURPOSE

In phase I studies with oral CI-1033, dose-limiting toxicities were primarily gastrointestinal, supporting the exploration of i.v. dosing to achieve optimal drug exposures by increasing bioavailability.

EXPERIMENTAL DESIGN

Fifty-three patients with advanced nonhematologic malignancies received i.v. CI-1033 via 30-minute infusions (10-500 mg) on a thrice-weekly schedule. Pharmacokinetic samples were collected on days 1 and 8 and evaluated using noncompartmental analysis.

RESULTS

Dose levels evaluated were 10, 20, 30, 45, 67.5, 100, 150, 225, 337.5, and 500 mg. The maximum administered dose was 500 mg, whereas the maximum tolerated dose was 225 mg. The most common treatment-related grade 1 to 2 adverse events were rashes (38% of patients), nausea (17%), vomiting (17%), stomatitis (14%), and diarrhea (13%). Most common grade 3 adverse events were hypersensitivity reactions (7.5%), rashes (3.8%), and diarrhea (3.8%). No grade 4 toxicities were observed. Ten of the 53 (19%) patients had disease stabilization at their first efficacy evaluation visit (including two with minor responses). A 5- to 10-fold increase in i.v. C(max) was noted with a 3-fold increase in AUC compared with oral CI-1033 at equivalent doses. Treatment-related gastrointestinal adverse events were notably less frequent with this i.v. regimen.

CONCLUSIONS

CI-1033 was safely given i.v. up to 225 mg/dose on a thrice-weekly schedule, with evidence of antitumor activity. At equivalent doses, the bioavailability of i.v. CI-1033 is thrice that of the oral formulation. Treatment with i.v. CI-1033 is feasible and may be warranted when increased drug exposures are desired.

Apoptosis in epithelial ovarian tumours Prognostic significance of clinical and histopathologic factors and its association with the immunohistochemical expression of apoptotic regulatory proteins (p53, bcl-2 and bax)

OBJECTIVE

The objective was to establish the importance of apoptosis-related genes and the apoptotic index (AI) as prognostic factors in patients with epithelial ovarian tumours.

MATERIAL AND METHODS

Tumour specimens from 130 epithelial ovarian tumours were examined for expression of p53, bcl-2 and bax proteins. The apoptotic index was evaluated by modified terminal deoxynucleotide-transferase-mediated digoxigenin triphosphate-biotin nick end-labelling (TUNEL) methods and by haematoxylin-eosin (H-E) staining. Other clinical and histopathological variables were also analysed. Statistical analyses were performed using the SPSS 10.0 package.

RESULTS

The apoptotic index detected by H-E and enzymatic assay was high in the majority of carcinomas (serous, endometrioid and clear cell (p=0.001). In the univariate survival analysis, high apoptotic index, high p53 and low bcl-2 expression, significantly correlated with shorter survival and shorter disease-free periods (p<0.01). In multivariate analysis the age (p=0.026; CI: 1.035-1.066 and p=0.011; CI: 1.835-2.077), FIGO stage (p=0.017; CI: 1.385-4.514 and p=0.024; CI: 1.217-1.940), p53 expression (p=0.03; CI: 1.017-1.627 and p=0.02; CI: 1.050-2.350) and apoptotic index (p=0.019; CI: 1.375-1.750 and p=0.019; CI: 1.442-2.085) were revealed to be independent prognostic factors for survival and recurrence, respectively.

CONCLUSIONS

Our results indicate that the apoptotic index and p53 nuclear accumulation are independent predictive factors of recurrence and short survival. Our data also suggest different patterns of alterations for the various tumour types.

EGF-stimulated migration in ovarian cancer cells is associated with decreased internalization, increased surface expression, and increased shedding of the urokinase plasminogen activator receptor

OBJECTIVES

The EGFR is expressed in malignant ovarian tumor tissue, and tissue content of EGFR has been directly associated with poor prognosis in patients with ovarian cancer. The uPA system plays a role in pericellular proteolysis, cell migration, invasion, and is over-expressed in ovarian cancer. This study explored the effects of EGF on uPAR expression in the ovarian cancer cell line OVCAR-3.

METHODS

We used OVCAR-3 cells and the following methods: cell migration assay, time-lapse video microscopy, real-time PCR, assays for cellular binding of 125I-uPA and cellular degradation of 125I-uPA:PAI-1 complex, biosynthetic labeling using 35S-methionin, Western blot, Northern blot, and ELISAs for uPA, PAI-1, and uPAR.

RESULTS

EGF up-regulates both protein and mRNA not only for uPAR, but also for the ligand uPA and its inhibitor PAI-1. Cell surface uPAR, in control as well as EGF-stimulated cells, is present only in the intact, not the cleaved, form. Ligand binding experiments showed an increase of endogenously occupied uPAR, whereas non-occupied receptor sites were not increased. In addition, EGF treatment resulted in decreased degradation of radiolabeled uPA:PAI-1 complex. This suggests decreased internalization of uPAR, since the complex is internalized together with uPAR. Like EGF, colchicine, which inhibits endocytosis, increased cell surface expression of uPAR. In addition, we found an immediate increase of uPAR after exposing the cells to EGF and this was accompanied by a transient increase of cell migration. The increase of cell surface uPAR in response to EGF is accompanied by increased release of the soluble form of uPAR (suPAR) to the medium as well as by increased cell migration. Both uPAR and suPAR increased in cells treated with the endocytosis inhibitor colchicine even though cell migration was inhibited, suggesting that the mechanism of uPAR shedding is not related to cell migration.

CONCLUSION

Increased cell surface uPAR in response to EGF stimulation results from mobilization of uPAR from detergent-resistant domains, increased expression of uPAR mRNA, and decreased internalization and degradation of uPAR. Both the anti-uPAR antibody R3, which inhibits binding of uPA, and the EGFR phosphorylation inhibitor Iressa inhibited cell migration in response to uPA as well as to EGF, suggesting that EGFR and uPAR are engaged in the same multiprotein assembly on the cell surface.

Multicenter, randomized phase II trial of oral CI-1033 for previously treated advanced ovarian cancer

PURPOSE

To evaluate the antitumor activity and toxicity of two doses of CI-1033 in patients with platinum-refractory or recurrent ovarian cancer, and to determine baseline expression of epidermal growth factor receptor in tumor cells.

PATIENTS AND METHODS

This phase II, open-label clinical trial evaluated CI-1033 in patients with ovarian cancer who failed prior platinum-based therapy. Two oral doses of CI-1033 were evaluated--a 50-mg and a 200--mg oral dose administered daily for 21 days in a 28-day cycle. Patients were evaluated for tumor response and toxicity; in addition, archival baseline tumor samples were analyzed by immunohistochemistry for erbB1 to erbB4 status.

RESULTS

One hundred five eligible patients were treated. Baseline demographic characteristics were balanced in this heavily pretreated patient population. The median number of prior chemotherapy regimens received was four. The most commonly encountered drug-related adverse events for both dose arms were gastrointestinal (diarrhea, nausea, stomatitis) toxicity, asthenia, and rash. No responses were observed. Stable disease was confirmed in 34% and 26% of patients in the 200-mg and 50-mg arms, respectively, and 1-year survival rates were 38.5% and 37.7%, respectively. Baseline erbB3 and erbB4 revealed the highest frequencies of expression, while erbB2 was the lowest.

CONCLUSION

CI-1033 did not show activity in unscreened patients with advanced ovarian cancer. At 50 mg/d, CI-1033 had a more favorable adverse events profile than at 200 mg/d. erbB3 and erbB4 receptors showed the highest expression in tumor samples while erbB2 revealed the least. There appears to be no association between baseline erbB expression and disease stability.

Efficacy and safety of erlotinib HCl, an epidermal growth factor receptor (HER1/EGFR) tyrosine kinase inhibitor, in patients with advanced ovarian carcinoma: results from a phase II multicenter study

The aim of this single-arm, phase II study was to estimate the tumor response rate and safety profile of erlotinib HCl (erlotinib, Tarceva, OSI-774) monotherapy in patients with refractory, recurrent, HER1/EGFR-positive epithelial ovarian tumors, who had failed prior taxane and/or platinum-based chemotherapy. Thirty-four patients received 150 mg erlotinib orally once daily for up to 48 weeks or until disease progression or dose-limiting toxicity. Two patients had partial responses, lasting 8+ and 17 weeks, giving an objective response rate of 6% (95% confidence interval [CI], 0.7-19.7%). Fifteen patients (44%) had stable disease, and 17 patients (50%) had progressive disease. Median overall survival was 8 months (95% CI, 5.7-12.7 months), with a 1-year survival rate of 35.3% (95% CI, 19.8-53.5%). Patients with rash survived significantly longer than those without (P= 0.009), correlating with rash grade. Erlotinib was generally well tolerated. The most frequent erlotinib-related adverse events were rash (68%) and diarrhea (38%). Erlotinib had marginal activity but was generally well tolerated. The safety profile appears more favorable than typically experienced with standard chemotherapeutic agents, which is encouraging in these heavily pretreated patients. Combination of erlotinib with chemotherapy or other targeted agents should be considered.

Enhanced sensitivity to the HER1/epidermal growth factor receptor tyrosine kinase inhibitor erlotinib hydrochloride in chemotherapy-resistant tumor cell lines

PURPOSE

Erlotinib (Tarceva, OSI-774) is a potent and specific inhibitor of the HER1/epidermal growth factor receptor (EGFR) tyrosine kinase. In phase II clinical studies, oral erlotinib monotherapy has shown antitumor activity in patients with advanced non-small cell lung cancer, head and neck cancer, and ovarian cancer after the failure of standard chemotherapy. We hypothesized that some tumors treated with multiple cytotoxic therapies may become more dependent on the HER1/EGFR signaling pathways for survival.

EXPERIMENTAL DESIGN

The growth-inhibitory effect of erlotinib was tested on 10 pairs of chemosensitive, parental, and chemoresistant tumor cell lines.

RESULTS

Enhanced sensitivity to erlotinib was observed in the doxorubicin-resistant human breast cancer cell line MCF-7, paclitaxel-resistant human ovarian carcinoma cell line A2780, and cisplatin-resistant human cervical carcinoma cell line ME180. The IC(50) values of erlotinib in the resistant cell lines were 2- to 20-fold lower than those in the corresponding parental cell lines. This enhanced sensitivity to erlotinib correlated with higher HER1/EGFR and phospho-HER1/EGFR expression when compared with the corresponding parental cell lines. Acquired resistance to cytotoxic agents was not associated with cross-resistance to erlotinib. AE-ME180/CDDP-resistant xenografts showed greater sensitivity to erlotinib than parental ME180 xenografts did.

CONCLUSIONS

Our findings suggest that acquired resistance to cytotoxic therapy in some tumors is associated with enhanced sensitivity to HER1/EGFR inhibitors, which correlates with increased HER1/EGFR expression. These data may explain some of the observed clinical activity of HER1/EGFR inhibitors in patients previously treated with multiple therapies. HER1/EGFR tyrosine kinase inhibitors may be more effective as second- or third-line treatment for certain patients with tumors that were previously treated with multiple chemotherapy regimens.

Plasma vascular endothelial growth factor and interleukin-8 as biomarkers of antitumor efficacy of a prototypical erbB family tyrosine kinase inhibitor

CI-1033 (N-[4-[N-(3-chloro-4-fluorophenyl)amino-7-[3-(4-morpholynyl)propoxy]quinazolin-6-yl]acrylamide, PD 0183805-mesylate salt) was identified as a potent, selective inhibitor of erbB family tyrosine kinases, which are overexpressed in a number of solid tumors and have been shown to be involved in tumor progression. Because objective response of clinical patients to erbB-targeted therapies like CI-1033 has been observed only in a subset of cancer patients that exhibit the intended molecular targets, much emphasis has been placed on the identification of biomarkers of antitumor efficacy. Vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) were considered as potential biomarkers for CI-1033 due to ease of detection in patient plasma and showed roles in angiogenesis and cancer progression and positive regulation by the erbB receptor family. In the present studies, mice bearing established xenografts (A431 epidermoid carcinoma, H125 non-small cell lung carcinoma, SF767 glioblastoma, and MDA-MB-468 mammary carcinoma) were treated with efficacious and subefficacious doses of CI-1033, and plasma levels and xenograft gene expression of VEGF and IL-8 were evaluated. Oral administration of CI-1033 to tumor-bearing mice at efficacious doses resulted in markedly decreased levels of VEGF and/or IL-8 plasma levels and tumor mRNA levels relative to vehicle-treated control mice in xenograft models that exhibited evaluable levels of these markers. In contrast, subefficacious doses of CI-1033 did not significantly affect VEGF or IL-8 levels in any of the xenograft models. These studies indicate that plasma VEGF and IL-8 may have use as biomarkers of antitumor efficacy for epidermal growth factor receptor/erbB-targeted therapies such as CI-1033 and suggest that further clinical study of these markers in cancer patients are warranted.

Expression of progesterone receptor is a favorable prognostic marker in ovarian cancer

OBJECTIVE

Receptors for estrogen (ER), progesterone (PR), or androgen (AR) are predictive and prognostic markers of malignancy of multiple endocrine organs, including endometrial and breast cancer. However, the role of ERs, PRs, or ARs in the carcinogenesis of ovarian cancer, another sex hormone-dependent malignancy, is still controversial despite numerous studies that have attempted to determine their role. The disagreement in the findings may result from the fact that the numbers of tumor samples in studies have been small and that different immunohistochemical methods have been used that can introduce variation in the scoring of the histology. We therefore examined the pattern of expression of ERs, PRs, and ARs in a large number of samples of primary ovarian carcinoma by using a tissue microarray technique.

METHODS

We constructed a tissue microarray with 322 samples of primary ovarian carcinoma obtained at surgery performed at The University of Texas M. D. Anderson Cancer Center between 1990 and 2000. Immunohistochemistry studies were performed by using the immunoperoxidase technique against primary antibodies (ER, PR, and AR).

RESULTS

ERs, PRs, and ARs were differently expressed in different histotypes of ovarian cancer: ERs were expressed in 77.3% of all cases but more highly expressed in serous and endometrioid types; PRs were expressed in 26.2% of all cases but most highly expressed in the endometrioid type < 64.2%; and ARs were expressed in 43.7% of all cases but were most highly expressed in serous (47.5%) carcinomas. Of particular importance, the expression of PRs, but not ERs or ARs, was associated with better survival (P < 0.0001) in univariate and multivariate analyses.

CONCLUSIONS

The PR is an independent marker, with its overexpression associated with a favorable prognosis in women with ovarian cancer.

Administration of CI-1033, an irreversible pan-erbB tyrosine kinase inhibitor, is feasible on a 7-day on, 7-day off schedule: a phase I pharmacokinetic and food effect study

PURPOSE

To determine the maximum tolerated dose of administrating CI-1033, an oral 4-anilinoquinazoline that irreversibly inhibits the tyrosine kinase domain of all erbB subfamilies, on an intermittent schedule, and assess the interaction of CI-1033 with food on the pharmacokinetic behavior.

EXPERIMENTAL DESIGN

Escalating doses of CI-1033 from a dose level of 300 mg/day for 7 days every other week were administered to patients with advanced solid malignancies. Plasma concentration-time data sets from all evaluable patients were used to develop a population pharmacokinetic model. Noncompartmental methods were used to independently assess the effect of a high-fat meal on CI-1033 absorption and bioavailability.

RESULTS

Twenty-four patients were treated with 69 twenty-eight day courses. The incidence of unacceptable toxicity, principally diarrhea and skin rash, was observed at the 300 mg/day dose level. At the 250 mg/day level, toxicity was manageable, and protracted administration was feasible. A one-compartment linear model with first-order absorption and elimination adequately described the pharmacokinetic disposition. CL/F, apparent volume of distribution (Vd/F), and ka (mean +/- relative SD) were 280 L/hour +/- 33%, 684 L +/- 20%, and 0.35 hour(-1)+/- 69%, respectively. Cmax values were achieved in 2 to 4 hours. Systemic CI-1033 exposure was largely unaffected by administration of a high-fat meal. At 250 mg, concentration values exceeded IC50 values required for prolonged pan-erbB tyrosine kinase inhibition in preclinical assays.

CONCLUSIONS

The recommended dose on this schedule is 250 mg/day. Its tolerability and the biological relevance of concentrations achieved at the maximal tolerated dose warrant consideration of disease-directed evaluations. This intermittent treatment schedule can be used without regard to meals.

Establishment of a human non-small cell lung cancer cell line resistant to gefitinib

The epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitor gefitinib (Iressa, ZD1839) has shown promising activity preclinically and clinically. Because comparative investigations of drug-resistant sublines with their parental cells are useful approaches to identifying the mechanism of gefitinib resistance and select factors that determine sensitivity to gefitinib, we established a human non-small cell lung carcinoma subline (PC-9/ZD) that is resistant to gefitinib. PC-9/ZD cells are approximately 180-fold more resistant to gefitinib than their parental PC-9 cells and PC-9/ZD cells do not exhibit cross-resistance to conventional anticancer agents or other tyrosine kinase inhibitors, except AG-1478, a specific inhibitor of EGFR. PC-9/ZD cells also display significant resistance to gefitinib in a tumor-bearing animal model. To elucidate the mechanism of resistance, we characterized PC-9/ZD cells. The basal level of EGFR in PC-9 and PC-9/ZD cells was comparable. A deletion mutation was identified within the kinase domain of EGFR in both PC-9 and PC-9/ZD, but no difference in the sequence of EGFR cDNA was detected in either cell line. Increased EGFR/HER2 (and EGFR/HER3) heterodimer formations were demonstrated in PC-9/ZD cells by chemical cross-linking and immunoprecipitation analysis in cells unexposed to gefitinib. Exposure to gefitinib increased heterodimer formation in PC-9 cells, but not in PC-9/ZD cells. Gefitinib inhibits EGFR autophosphorylation in a dose-dependent manner in PC-9 cells but not in PC-9/ZD cells. A marked difference in inhibition of site-specific phosphorylation of EGFR was observed at Tyr1068 compared to other tyrosine residues (Tyr845, 992 and 1045). To elucidate the downstream signaling in the PC9/ZD cellular machinery, complex formation between EGFR and its adaptor proteins GRB2, SOS, and Shc was examined. A marked reduction in the GRB2-EGFR complex and absence of SOS-EGFR were observed in PC-9/ZD cells, even though the protein levels of GRB2 and SOS in PC-9 and PC-9/ZD cells were comparable. Expression of phosphorylated AKT was increased in PC-9 cells and inhibited by 0.02 microM gefitinib. But the inhibition was not significant in PC-9/ZD cells. These results suggest that alterations of adaptor-protein-mediated signal transduction from EGFR to AKT is a possible mechanism of the resistance to gefitinib in PC-9/ZD cells. These phenotypes including EGFR-SOS complex and heterodimer formation of HER family members are potential biomarkers for predicting resistance to gefitinib.

Receptor Imaging in Oncology by Means of Nuclear Medicine: Current Status

To date, our understanding of the role of receptors and their cognate ligands in cancer is being successfully translated into the design and development of an arsenal of new, less toxic, and more specific anticancer drugs. Because most of these novel drugs are cytostatic, objective response as measured by morphologic imaging modalities (eg, computed tomography or magnetic resonance imaging) cannot be used as a surrogate marker for drug development or for clinical decision making. Positron emission tomography (PET) can be used to image and quantify the in vivo distribution of positron-emitting radioisotopes such as oxygen-15, carbon-11, and fluorine-18 that can be substituted or added into biologically relevant and specific receptor radioligands. Similarly, single-photon emission computed tomography (SPECT) can be used to image and quantify the in vivo distribution of receptor targeting compounds labeled with indium-111, technetium-99m, and iodine-123. By virtue of their whole-body imaging capacity and the absence of errors of sampling and tissue manipulation as well as preparation, both techniques have the potential to address locoregional receptor status noninvasively and repetitively. This article reviews available data on the in vivo evaluation of receptor systems by means of PET or SPECT for identifying and monitoring patients with sufficient receptor overexpression for tailored therapeutic interventions, and also for depicting tumor tissue and determining the currently largely unknown heterogeneity in receptor expression among different tumor lesions within and between patients.

Estrogen receptor-positive human epithelial ovarian carcinoma cells respond to the antitumor drug suramin with increased proliferation: possible insight into ER and epidermal growth factor signaling interactions in ovarian cancer

OBJECTIVES

Development of targeted therapeutics for ovarian cancer requires a basic understanding of ovarian epithelial carcinoma cell biology. The role of estrogen and epidermal growth factor (EGF) in control of cell growth was investigated in a panel of ovarian carcinoma lines.

METHODS

EGF receptor (EGFR) was detected by flow cytometry and estrogen receptor (ER) by Northern blot. Western blotting and [(3)H]thymidine incorporation were used to determine receptor activation and the effects of ligand exposure and growth factor antagonists, including the antineoplastic agent, suramin, on cell growth.

RESULTS

Only one cell line, OV266, expressed ER and responded to beta-estradiol with increases in DNA synthesis and cell proliferation that could be blocked by the pure antiestrogen ICI 182,780. All cell lines possessed functional EGFR as measured by flow cytometry and phosphorylation of the receptor and mitogen-activated protein kinase after EGF treatment, but only two cell lines (OV177 and OV266) proliferated in response to exogenous EGF. Suramin had limited effectiveness in inhibiting growth in four of five cell lines and had a striking dose-dependent stimulatory effect on OV266 cell growth. The proliferative response to suramin could be inhibited with EGFR antagonists.

CONCLUSION

Cultured epithelial ovarian carcinoma cell lines express EGFR (5/5) and can express ER (1/5). Differential growth responses to EGF were observed despite uniform receptor and MAPK activation. Unexpectedly, the antineoplastic agent suramin increased growth of ER positive ovarian carcinoma cells in an EGFR-dependent manner. These studies provide insight into the complex interactions of these systems in control of ovarian cancer cell growth.

Lack of relationship between EGFR-1 immunohistochemical expression and prognosis in a multicentre clinical trial of 93 patients with advanced primary ovarian epithelial cancer (GINECO group)

Epidermal growth factor receptor 1 (EGFR-1) overexpression is usually described as linked with a worse prognosis in a variety of tumours of epithelial origin. However, its role in ovarian cancer is still controversial. The aim of the present study was to analyse the prognostic impact of EGFR-1 in a retrospective series of 93 stage III–IV primary ovarian epithelial tumours. All patients, enrolled in a multicentre GINECO prospective clinical trial, were treated with the same platinum-based combination chemotherapy, and were followed up with a median of 69 months. Epidermal growth factor receptor 1 plasma membrane expression, assessed by immunohistochemistry on paraffin-embedded tissues, was correlated with clinical parameters as well as immunohistochemical expression results of HER-2 (c-erbB-2), BAX, BCL-2, p53 and anti-Ki-67, previously studied in the same series of patients. Positive immunostaining for EGFR-1 was seen in 31 of the 93 analysed cases (33%). No correlation was found between EGFR-1 expression and clinical parameters. No correlation was found between EGFR-1 expression and other biological markers, except for HER-2, which was limit for significance. Indeed, among the EGFR-1-negative cases, 10.3% expressed HER-2, whereas the HER-2-expressing tumours accounted for 27.6% of EGFR-1-positive cases (P=0.06). Epidermal growth factor receptor 1 overexpression had no prognostic impact on both overall and progression-free survival through univariate and multivariate analyses. The potential effect of EGFR-1 and HER-2 co-expression on targeted therapy against EGFR-1 and/or HER-2 molecules has to be further analysed.

Involvement of estrogen receptor beta in ovarian carcinogenesis

Knockout and expression studies suggest that estrogen receptor beta (ERbeta) plays a prominent role in ovarian function and pathology. Moreover, ovarian cancers are characterized by high morbidity and low responsiveness to anti-estrogens. Here we demonstrate, using quantitative PCR to measure ERalpha and ERbeta levels in 58 ovarian cancer patients, that ERbeta expression decreased in cysts and ovarian carcinomas as compared with normal ovaries and that this decrease is attributable only to a selective loss in ERbeta expression during cancer progression. To address the question of a possible involvement of ERbeta in ovarian cancers, we restored ERalpha and ERbeta expression in two human ovarian cancer cell lines PEO14 (ERalpha-negative) and BG1 (ERalpha-positive) using adenoviral delivery. ERalpha, but not ERbeta, could induce progesterone receptor and fibulin-1C. Moreover, ERalpha and ERbeta had opposite actions on cyclin D1 gene regulation, because ERbeta down-regulated cyclin D1 gene expression, whereas ERalpha increased cyclin D1 levels. Interestingly, ERbeta expression strongly inhibited PEO14 and BG1 cell proliferation and cell motility in a ligand-independent manner, whereas ERalpha had no marked effect. Induction of apoptosis by ERbeta also contributed to the decreased proliferation of ovarian cancer cells, as shown by Annexin V staining. This study shows that ERbeta is an important regulator of proliferation and motility of ovarian cancer and provides the first evidence for a proapoptotic role of ERbeta. The loss of ERbeta expression may thus be an important event leading to the development of ovarian cancer.

Targeting the HER-kinase axis in cancer

The human epidermal growth factor receptor (HER) family of receptor tyrosine kinases controls critical pathways involved in the differentiation, growth, division, and motility of normal epithelial cells. Most human solid tumors are of epithelial origin. The process of malignant transformation and progression in many cancers may depend on activation of ligands and receptors that function as part of the HER-kinase pathway. This signaling axis has earned increased attention because of the development of antibodies and small-molecule tyrosine kinase inhibitors that specifically target components of the HER-kinase axis for cancer therapy. This review focuses on the basic biology underlying HER-kinase pathway activation and the current state of development for agents that target this axis. In particular, the importance of pan-HER inhibitors is discussed.