The prognostic importance of cyclooxygenase 2 and HER2 expression in epithelial ovarian cancer

Identification of a novel ferroptosis-related gene signature associated with prognosis, the immune landscape, and biomarkers for immunotherapy in ovarian cancer

Ferroptosis has been implicated in tumor progression and immunoregulation. Identification of ferroptosis-related prognostic gene is important for immunotherapy and prognosis in ovarian cancer (OV). We assessed the potential predictive power of a novel ferroptosis-related gene (FRG) signature for prognosis and immunotherapy in Asian and Caucasian OV populations. We collected gene expression profiles and clinicopathological data from public databases. The least absolute shrinkage and selection operator Cox regression algorithm was used to construct the FRG signature. Receiver operating characteristic (ROC) curve, Kaplan-Meier method, Cox regression model were used to evaluate the clinical benefits of FRG signature. Gene functional and gene set enrichment analyses were used for functional annotation and immune landscape analysis. A 15-FRG signature was constructed and used to stratify patients into two risk groups. Patients in the high-risk group had significantly worse survival. The risk score was a significant independent risk factor for OS. The area under the ROC curve indicated the good prediction performance of the FRG signature. Notably, the low-risk group showed a significant enrichment in immune-related pathways and a “hot” immune status. The risk score was found to be an efficient and robust predictor of response to immunotherapy. In conclusion, our study identified a novel 15-FRG prognostic signature that can be used for prognostic prediction and precision immunotherapy in Asian and Caucasian OV populations.

Gene expression profiles and pathway enrichment analysis to identification of differentially expressed gene and signaling pathways in epithelial ovarian cancer based on high-throughput RNA-seq data

Epithelial ovarian cancer (EOC) can be considered as a stressful and challenging disease among all women in the world, which has been associated with a poor prognosis and its molecular pathogenesis has remained unclear. In recent years, RNA Sequencing (RNA-seq) has become a functional and amazing technology for profiling gene expression. In the present study, RNA-seq raw data from Sequence Read Archive (SRA) of six tumor and normal ovarian sample was extracted, and then analysis and statistical interpretation was done with Linux and R Packages from the open-source Bioconductor. Gene Ontology (GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were applied for the identification of key genes and pathways involved in EOC. We identified 1091 Differential Expression Genes (DEGs) which have been reported in various studies of ovarian cancer as well as other types of cancer. Among them, 333 genes were up-regulated and 273 genes were down-regulated. In addition, Differentially Expressed Genes (DEGs) including RPL41, ALDH3A2, ERBB2, MIEN1, RBM25, ATF4, UPF2, DDIT3, HOXB8 and IL17D as well as Ribosome and Glycolysis/Gluconeogenesis pathway have had the potentiality to be used as targets for EOC diagnosis and treatment. In this study, unlike that of any other studies on various cancers, ALDH3A2 was most down-regulated gene in most KEGG pathways, and ATF4 was most up-regulated gene in leucine zipper domain binding term. In the other hand, RPL41 as a regulatory of cellular ATF4 level was up-regulated in many term and pathways and augmentation of ATF4 could justify the increase of RPL41 in the EOC. Pivotal pathways and significant genes, which were identified in the present study, can be used for adaptation of different EOC study. However, further molecular biological experiments and computational processes are required to confirm the function of the identified genes associated with EOC.

HER2 Protein Overexpression and Gene Amplification in Tubo-Ovarian High-grade Serous Carcinomas

Most tubo-ovarian high-grade serous carcinomas (TO-HGSC) are diagnosed in advanced stages. Although the majority of patients achieve initial remission with cytoreductive surgery and chemotherapy, mortality rate remains high due to recurrent/progressive disease. The addition of trastuzumab to carboplatin-paclitaxel improved progression-free survival of patients with human epidermal growth factor receptor 2 (HER2)-positive uterine serous carcinoma. After this encouraging result of transtuzumab in HER2-positive uterine serous carcinoma, we aimed to determine the frequency of HER2 overexpression/amplification in TO-HGSC and reveal the utility of 2018 ASCO/CAP HER2 testing guideline in breast cancer for TO-HGSC. For 100 cases, HER2 protein expression was assessed by immunohistochemistry and scored from 0 to 3+ according to 2018 ASCO/CAP HER2 testing guideline. HER2 gene amplification was assessed by florescence in situ hybridization for all the 2+ and 3+ cases as well as 5 of the 0/1+ cases. Among 100 cases, immunohistochemistry scores were 0/1+ in 81 cases, 2+ in 18 cases and 3+ in 1 case. By florescence in situ hybridization, the only 3+ case and 1 of the 2+ cases were HER2-amplified and all 5 of the 0/1+ cases were HER2 nonamplified. Subclonal HER2 overexpression/amplification was identified in 1 of the neoadjuvant cases comprising <10% of the entire tumor. In summary, HER2 overexpression/amplification was found in 2% of TO-HGSC. The 2018 ASCO/CAP HER2 testing guideline in breast cancer can be utilized for TO-HGSC. Future studies are needed to explore HER2-targeted therapies in TO-HGSC and expand the patient population who may benefit from HER2-targeted therapies such as patients with activating mutations in HER2 gene without overexpression/amplification.

Peptide Ligands Specifically Targeting HER2 Receptor and the Role Played by a Synthetic Model System of the Receptor Extracellular Domain: Hypothesized Future Perspectives

A short (Fab)trastuzumab-derived peptide specific for HER2 receptor was identified. Its affinity for the model system HER2-DIVMP was found in a nanomolar range. The structural determinants responsible for the interaction between this ligand (A9) and HER2-DIVMP were investigated by both computational and NMR analysis. Next, the possibility of using A9 as HER2- specific probe for the nuclear medicine imaging was evaluated by conjugating A9 with the DTPA chelator and radiolabeling it with ¹¹¹In. The developed probe retained a nanomolar affinity to HER2-overexpressing cancer cells, however, some unspecific binding also occurred. The peptide internalization into cells by receptor-mediated endocytosis was also studied. Future perspectives are aimed at using A9 as a probe for molecular imaging diagnostics as well as active targeting of anticancer drugs. Lead structure optimization is needed to minimize the percentage of A9 unspecific binding and to increase the binding affinity to the receptor.

Design, synthesis, and computational validation of novel compounds selectively targeting HER2-expressing breast cancer

Human epidermal growth factor receptor (HER) is a family of multidomain proteins that plays important role in the regulation of several biological functions. HER2 is a member of HER that is highly presented in breast cancer cells. Here, we designed and synthesized a series of diaryl urea/thiourea compounds. The compounds were tested on HER2⁺ breast cancer cells including MCF-7 and SkBr3, compared to HER2^- breast cancer cells including MDA-MB-231 and BT-549. Only compounds 12-14 at 10 µM showed selective anti-proliferative activity against MCF-7 and SkBr3 by 65-79%. Compounds 12-14 showed >80% inhibition of the intracellular kinase domain of HER2. The results obtained indicated that compounds 12-14 are selectively targeting HER2⁺ cells. The IC₅₀ of compound 13 against MCF-7 and SkBR3 were 1.3 ± 0.009 and 0.73 ± 0.03 µM, respectively. Molecular docking and MD simulations (50 ns) were carried out, and their binding free energies were calculated. Compounds 12-14 formed strong hydrogen bond and pi-pi stacking interactions with the key residues Thr862 and Phe864. 3DQSAR model confirmed the role of 3-bromo substituent of pyridine ring and 4-chloro substituent of phenyl ring in the activity of the compounds. In conclusion, novel compounds, particularly 13 were developed selectively against HER2-expressing/overexpressing breast cancer cells including MCF7 and SkBr3.

Dual Actions of Ketorolac in Metastatic Ovarian Cancer

Cytoreductive surgery and chemotherapy are cornerstones of ovarian cancer treatment, yet disease recurrence remains a significant clinical issue. Surgery can release cancer cells into the circulation, suppress anti-tumor immunity, and induce inflammatory responses that support the growth of residual disease. Intervention within the peri-operative window is an under-explored opportunity to mitigate these consequences of surgery and influence the course of metastatic disease to improve patient outcomes. One drug associated with improved survival in cancer patients is ketorolac. Ketorolac is a chiral molecule administered as a 1:1 racemic mixture of the S- and R-enantiomers. The S-enantiomer is considered the active component for its FDA indication in pain management with selective activity against cyclooxygenase (COX) enzymes. The R-enantiomer has a previously unrecognized activity as an inhibitor of Rac1 (Ras-related C3 botulinum toxin substrate) and Cdc42 (cell division control protein 42) GTPases. Therefore, ketorolac differs from other non-steroidal anti-inflammatory drugs (NSAIDs) by functioning as two distinct pharmacologic entities due to the independent actions of each enantiomer. In this review, we summarize evidence supporting the benefits of ketorolac administration for ovarian cancer patients. We also discuss how simultaneous inhibition of these two distinct classes of targets, COX enzymes and Rac1/Cdc42, by S-ketorolac and R-ketorolac respectively, could each contribute to anti-cancer activity.

Differential cyclooxygenase expression levels and survival associations in type I and type II ovarian tumors

BACKGROUND

High cyclooxygenase (COX)-2 expression in ovarian tumors has been associated with poor prognosis, but the role of COX-1 expression and its relation to survival is less clear. Here, we evaluated COX expression and associations with survival outcomes between type I (clear cell, mucinous, low grade endometrioid and low grade serous) and type II (high grade serous and high grade endometrioid) ovarian tumors.

METHODS

We developed and validated a new COX-1 antibody, and conducted immunohistochemical (IHC) staining for COX-1 and COX-2 on a tissue microarray (TMA) of 190 primary ovarian tumors. In addition to standard IHC scoring and H-scores to combine the percentage of positive cells and staining intensity, we also measured COX-1 and COX-2 mRNA expression by QPCR. High expression was defined as greater than or equal to median values. Clinical characteristics and disease outcomes were ascertained from medical records. Associations with disease-free survival (DFS) and overall survival (OS) were quantified by hazard ratios (HRs) and confidence intervals (CIs) from proportional hazards regression.

RESULTS

Type I tumors had high COX-2 expression, while type II tumors had high COX-1 expression. In multivariable adjusted regression models, higher COX-1 mRNA expression was associated with shorter DFS (HR: 6.37, 95% CI: 1.84-22.01) and OS (HR: 2.26, 95% CI: 1.04-4.91), while higher H-scores for COX-2 expression were associated with shorter DFS (HR: 1.92, 95% CI: 1.06-3.49). Stratified analysis indicated that COX-2 was significantly associated with DFS among cases with Type II tumors (HR: 1.93, 95% CI: 1.06-3.53).

CONCLUSIONS

These findings suggest that ovarian tumor type contributes to differences in COX expression levels and associations with survival.

Evaluation of HER2-specific peptide ligand for its employment as radiolabeled imaging probe

HER2 transmembrane receptor is an important target in immunotherapy treatment of breast and gastroesophageal cancer. Molecular imaging of HER2 expression may provide essential prognostic and predictive information concerning disseminated cancer and aid in selection of an optimal therapy. Radiolabeled low molecular weight peptide ligands are particularly attractive as probes for molecular imaging, since they reach and bind to the target and clear from non-target organs and blood stream faster than bulky antibodies. In this study, we evaluated a potential HER2-imaging probe, an A9 nonapeptide, derived from the trastuzumab-Fab portion. Its cellular uptake was investigated by mass spectrometry analysis of the cytoplasmic cellular extracts. Moreover, based on in-silico modeling, DTPA chelator was conjugated to N-terminus of A9. ¹¹¹In-labeled A9 demonstrated nanomolar affinity to HER2-expressing BT474 cells and favorable biodistribution profile in NMRI mice. This study suggests that the peptide A9 represents a good lead candidate for development of molecular probe, to be used for imaging purposes and for the delivery of cytotoxic agents.

The prognostic value of HER2 in ovarian cancer: A meta-analysis of observational studies

BACKGROUND

The prognostic role of human epidermal growth factor receptor 2 (HER2) in ovarian cancer has been investigated in previous studies, but the results remain controversial. Here we present a meta-analysis to systematically review the association between HER2 expression and ovarian cancer prognosis.

METHOD

Observational studies published until July 2017 were searched in Pubmed, Embase, and Cochrane library databases. Hazard ratios (HRs) for survival with 95% confidence intervals (CIs), subgroup analyses, publication bias and sensitivity analyses were implemented under a standard manner. Estimates of overall survival (OS), progress-free survival (PFS) and disease-free survival (DFS) were weighted and pooled using Der Simonian-Laird random-effect model.

RESULT

Thirty-four studies that include 5180 ovarian cancer patients were collected for analysis. Expression of HER2 was negatively correlated with clinical prognosis of overall survival (HR = 1.57, 95% CI: 1.31 to 1.89, P < 0.001) and disease-free survival / progress-free survival (HR = 1.26, 95% CI = 1.06 to 1.49) in ovarian cancers. The association between HER2 expression and poor ovarian cancer prognosis in overall survival was also statistically significant in subgroups of unclassified ovarian cancer, Caucasian population and Asian population, while irrespective of detection method.

CONCLUSION

HER2 expression was related with poor prognosis in ovarian cancer patients and can be used as a predicting cancer prognostic biomarker in ovarian cancer patients.

COX-2 expression in ovarian cancer: an updated meta-analysis

The prognostic role of COX-2 expression in ovarian cancer patients has been studied for years, while results remain controversial. Thus we performed a meta-analysis to evaluate the prognostic impact of COX-2 expression on survival of ovarian cancer patients. The databases PubMed, Embase and CNKI were searched. Summary hazard ratio (HR) and 95% confidence intervals (CIs) were calculated to analyze the correlations between COX-2 expression and overall survival (OS), and disease-free survival (DFS). A total of 1,867 patients from 18 studies were enrolled in the final analysis. The results showed that patients with higher COX-2 expression had a poor OS (HR: 1.48; 95% CI: 1.19-1.85) and DFS (HR: 1.81, 95% CI: 1.28-2.55). Subgroup analysis showed that there had significant associations between COX-2 expression and survival rate in most of the subgroups. Furthermore, there were significant associations between COX-2 expression and several clinical parameters such as FIGO stage, histological type and age. These results showed the patients with higher COX-2 expression had a significantly poorer survival rate, COX-2 expression had the potential to be a prognostic marker of ovarian cancer.

Superior in vitro and in vivo activity of trastuzumab-emtansine (T-DM1) in comparison to trastuzumab, pertuzumab and their combination in epithelial ovarian carcinoma with high HER2/neu expression

BACKGROUND

Epithelial ovarian cancer (EOC) remains the most lethal gynecologic malignancy. The objective of this study was to compare the anti-tumor activity of HER2/neu-targeting monoclonal antibodies, trastuzumab (T), pertuzumab (P), combination of trastuzumab and pertuzumab (T+P) and trastuzumab-emtansine (T-DM1) in EOC with high HER2/neu expression.

METHODS

Primary EOC cell lines were established and cell blocks were analyzed for HER2/neu expression. Cytostatic, apoptotic and antibody-dependent cell-mediated cytotoxicity (ADCC) activities of T, P, T+P and T-DM1 were evaluated in vitro. The in vivo antitumor activity was tested in xenograft models with 3+ HER2/neu expression.

RESULTS

High (3+) HER2/neu expression was detected in 40% of the primary EOC cell lines. T, P, T+P, and T-DM1 were similarly effective in inducing strong ADCC against primary EOC cell lines expressing 3+ HER2/neu. The combination of T and P was more cytostatic when compared with that of T or P used alone (p<0.0001 and p<0.0001, respectively). T-DM1 induced significantly more apoptosis when compared with T+P (p<0.0001). Finally, T-DM1 was significantly more effective in tumor growth inhibition in vivo in EOC xenografts overexpressing HER2/neu when compared to T alone, P alone and T+P (p=0.04).

CONCLUSION

In vitro and in vivo experiments with 3+ HER2/neu expressing EOC revealed limited anti-tumor activity of T or P. T-DM1 showed superior anti-tumor activity to T and P as single agents and as a combination. Our preclinical data support the design of clinical studies with T-DM1 for the treatment of chemotherapy-resistant EOC overexpressing HER2/neu.

Prognostic value of HER-2/neu expression in epithelial ovarian cancer: a systematic review and meta-analysis

This study aimed to conduct a meta-analysis to investigate the association between human epidermal growth factor receptor 2 (HER-2/neu) expression and survival in patients with epithelial ovarian cancer (EOC). HER-2/neu is one of the most frequently studied molecular biological parameters in EOC, but its prognostic impact has not been fully assessed. PubMed and Embase were searched for studies that reported HER-2/neu expression and survival in patients with EOC. The primary outcome was overall survival (OS), and the secondary outcome was progression-free survival (PFS). Hazard ratios (HRs) with 95% confidence interval (CI) were determined using Mantel-Haenszel random-effects model. Publication bias was investigated using funnel plots and Egger's test. A total of 56 studies (N=7212) were included in the analysis. The results showed that patients possessing HER-2/neu expression had significant disadvantages in OS (HR = 1.41; 95%CI, 1.31 to 1.51; P < 0.001) and PFS (HR = 1.38; 95% CI, 1.23-1.56; P < 0.001). The trim-and-fill method, Copas model, and subgroup analyses stratified by the study characteristics confirmed the robustness of the results. The present study findings provided further indication that HER-2/neu expression in patients with EOC has an adverse impact on OS and PFS.

Molecular Mechanisms and Translational Therapies for Human Epidermal Receptor 2 Positive Breast Cancer

Breast cancer is the second leading cause of cancer death among women. Human epidermal receptor 2 (HER2) positive breast cancer (HER2+ BC) is the most aggressive subtype of breast cancer, with poor prognosis and a high rate of recurrence. About one third of breast cancer is HER2+ BC with significantly high expression level of HER2 protein compared to other subtypes. Therefore, HER2 is an important biomarker and an ideal target for developing therapeutic strategies for the treatment HER2+ BC. In this review, HER2 structure and physiological and pathological roles in HER2+ BC are discussed. Two diagnostic tests, immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH), for evaluating HER2 expression levels are briefly introduced. The current mainstay targeted therapies for HER2+ BC include monoclonal antibodies, small molecule tyrosine kinase inhibitors, antibody-drug conjugates (ADC) and other emerging anti-HER2 agents. In clinical practice, combination therapies are commonly adopted in order to achieve synergistic drug response. This review will help to better understand the molecular mechanism of HER2+ BC and further facilitate the development of more effective therapeutic strategies against HER2+ BC.

The Effect of Cyclooxygenase-2 Expression in Uterine Carcinosarcoma on Survival: A Reassessment Based on Mature Data

OBJECTIVE

To reassess the effect cyclooxygenase-2 (COX-2) expression in carcinosarcoma on survival based on mature 5-year survival data.

METHOD

A comparison of 5-year survival of 27 patients with carcinosarcoma according to the presence of COX-2 immunohistochemical staining and staining score was performed.

RESULTS

The 5-year survival of those with positive and negative COX-2 staining was statistically not different. However, there was a clear trend for more favorable 5-year survival in patients with a high staining score than in those with a low score, and the difference was of borderline significance (38.5% vs 7.1%; P = 0.06).

CONCLUSION

In view of the role of COX-2 in carcinogenesis, our finding that COX-2 expression may confer a better survival in patients with carcinosarcoma is intriguing. Larger studies are indicated to elucidate the effect of COX-2 expression on survival in patients with carcinosarcoma because this may have therapeutic implications.

SKP2/P27Kip1 pathway is associated with Advanced Ovarian Cancer in Saudi Patients

BACKGROUND

Ovarian cancer is the most common gynecological malignancy and constitutes the fifth leading cause of female cancer death. Some biological parameters have prognostic roles in patients with advanced ovarian cancer and their expression may contribute to tumor progression. The aim of this study was to investigate the potential prognostic value of SKP2, genes P27Kip1, K-ras, c-Myc, COX2 and HER2 genes expression in ovarian cancer.

MATERIALS AND METHODS

This study was performed on two hundred formalin fixed paraffin embedded ovarian cancer and normal adjacent tissues (NAT). Gene expression levels were assessed using real time PCR and Western blotting.

RESULTS

Elevated expression levels of SKP2, K-ras, c-Myc, HER2 and COX2 genes were observed in 61.5% (123/200), 92.5% (185/200), 74% (148/200), 96 % (192/200), 90% (180/200) and 78.5% (157/200) of cancer tissues, respectively. High expression of SKP2 and down-regulation of P27 was associated with advanced stages of cancer.

CONCLUSIONS

The association between high expression of c-Myc and SKP2 with low expression of P27 suggested that the Skp2-P27 pathway may play an important role in ovarian carcinogenesis. Reduced expression of P27 is associated with advanced stage of cancer and can be used as a biological marker in clinical routine assessment and management of women with advanced ovarian cancer.

Hormone receptor, HER2/NEU and EGFR expression in ovarian carcinoma--is here a prognostic phenotype?

PURPOSE

We aimed to evaluate the effects of hormone receptor, HER2, and epidermal growth factor receptor (EGFR) expression on epithelial ovarian cancer (EOC) prognosis and investigate whether or not phenotypic subtypes might exist.

MATERIALS AND METHODS

The medical records of 82 patients who were diagnosed with EOC between 2003 and 2012 and treated by platinum-based chemotherapy were retrospectively evaluated. Expression of EGFR, oestrogen (ER), progesterone (PR), and cerbB2 (HER2) receptors were assessed immunohistochemically on paraffin-embedded tissues of these patients. Three phenotypic subtypes were defined according to ER, PR, and HER2 expression and associations of these with EGFR expression, clinicopathologic features, platinum sensitivity, and survival were investigated.

RESULTS

When we classified EOC patients into three subtypes, 63.4% had hormone receptor positive (HR(+)) (considering breast cancer subtypes, luminal A), 18.3% had triple negative, and 18.3% had HER2(+) disease. EGFR positivity was observed in 37 patients (45.1%) and was significantly more frequent with advanced disease (p=0.013). However, no significant association with other clinicopathologic features and platinum sensitivity was observed. HER2(+) patients had significantly poorer outcomes than HER2(-) counterparts (triple negative and HR positive patients) (p=0.019). Multivariate analysis demonstrated that the strongest risk factor for death was residual disease after primary surgery.

CONCLUSIONS

Triple negative EOC may not be an aggressive phenotype as in breast cancer. The HER2 positive EOC has more aggressive behaviour compared to triple negative and HR(+) phenotypes. EGFR expression is more frequent in advanced tumours, but is not related with poorer outcome. Additional ovarian cancer molecular subtyping using gene expression analysis may provide more reliable data.

The emerging role of the transcriptional coregulator RIP140 in solid tumors

RIP140 is a transcriptional coregulator (also known as NRIP1) which plays very important physiological roles by finely tuning the activity of a large number of transcription factors. Noticeably, the RIP140 gene has been shown to be involved in the regulation of energy expenditure, in mammary gland development and intestinal homeostasis as well as in behavior and cognition. RIP140 is also involved in the regulation of various oncogenic signaling pathways and participates in the development and progression of solid tumors. This short review aims to summarize the role of this transcription factor on nuclear estrogen receptors, E2F and Wnt signaling pathways based on recent observations focusing on breast, ovary, liver and colon tumors.

Role of HER family members in predicting prognoses in epithelial ovarian cancer: a meta-analysis

AIMS AND BACKGROUND

Human epidermal receptor (HER) family receptors are commonly overexpressed in various human tumors, and their overexpression is thought to play a critical role in tumor progression. The aim of this meta-analysis was to evaluate the prognostic significance of HER family members in epithelial ovarian cancer (EOC).

METHODS

Relevant studies published between January 1, 1980, and April 24, 2013, that evaluated the associations of HER family members with overall survival (OS), progression-free survival (PFS), response to platinum-based chemotherapy, lymph node metastasis, or ascites in EOC were identified via searches of PubMed and EMBASE.

RESULTS

We identified 37 eligible articles that met the inclusion criteria. The results of the meta-analysis revealed that significantly poorer OS of patients with EOC was predicted by high Her-2 expression levels (hazard ratio [HR] 1.69, 95% confidence interval [CI] 1.31-2.19). Furthermore, high Her-2 expression was significantly associated with poor PFS (HR 1.88, 95% CI 1.46-2.41) and an increased risk of ascites (risk ratio 1.21, 95% CI 1.02-1.42).

CONCLUSIONS

High levels of expression of Her-2 are significantly related to poor survival and an increased risk of ascites in patients with EOC. Future prospective cohorts with larger samples are needed to verify the prognostic value of Her-2 expression in EOC.

Downregulation of human epidermal growth factor receptor 2 by short hairpin RNA increases chemosensitivity of human ovarian cancer cells

The aim of the current study was to investigate the suppressive effects of pSilencer T7-human epidermal growth factor receptor 2 (HER2)-short hairpin RNA (shRNA) recombinant plasmids on human SKOV3 ovarian cancer cell growth and sensitivity to carboplatin (CBP). Three different pairs of shRNAs (shRNAa, shRNAb and shRNAc), targeting the HER2 gene, were selected and transfected into human SKOV3 cells, respectively. The expression levels of HER2 were then detected by immunohistochemical (IHC), semi-quantitative reverse transcription-polymerase chain reaction and western blot analyses. In addition, cell cycle and cell growth were investigated using cell counting kit-8 (CCK-8). The results of the IHC and western blot analyses revealed that shRNAb significantly inhibited HER2 protein expression in SKOV3 cells. shRNAb exhibited an improved effect on HER2 expression compared with shRNAa (P<0.01), while shRNAc did not affect HER2 expression. Nontransfected and nonspecific shRNA groups were used as the negative controls. Knockdown of HER2 expression by shRNA was initiated at 24 h following transfection, achieving an optimum effect at 48 h and lasting for at least 72 h after the treatment. The CCK-8 cell growth assay indicated that the knockdown of HER2 expression in the SKOV3 cell line resulted in significant growth suppression and cell cycle arrest. In addition, inhibition of HER2 significantly increased SKOV3 cell sensitivity to CBP treatment. In conclusion, pSilencer T7-HER2-shRNA significantly inhibited HER2 expression in human ovarian cancer cells in vitro and induced chemotherapeutic sensitivity to CBP.

Prognostic value of HER-2/neu expression in epithelial ovarian cancer: a meta-analysis

Various studies examined the relationship between human epidermal growth factor receptor 2 (HER-2/neu) overexpression and the clinical outcome in patients with ovarian cancer, but yielded conflicting results. Electronic databases updated in May 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between HER-2/neu overexpression and survival of patients with ovarian cancer. Survival data were aggregated and quantitatively analyzed. We conducted a final analysis of 3,055 patients from 20 eligible studies and evaluated the correlation between HER-2/neu overexpression and survival in patients with ovarian cancer. Combined hazard ratios suggested that HER-2/neu overexpression was not associated with a significant impact on survival, with the hazard ratio (HR) and 95% confidence interval (CI) being 1.05 and 0.92-1.19, respectively, overall. When grouped according to the study design type, a statistically significant combined HR was found in retrospective studies (HR = 1.44, 95% CI 1.14-1.75) and no statistically significant combined HR was found (HR = 0.96, 95% CI 0.81-1.11) for prospective studies. HER-2/neu overexpression seems to have no significant impact on survival of ovarian cancer patients. However, a statistically significant combined HR was found in retrospective studies, but not in prospective studies.

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.

Molecular characterization of mucinous ovarian tumours supports a stratified treatment approach with HER2 targeting in 19% of carcinomas

Mucinous ovarian carcinomas (MCs) typically do not respond to current conventional therapy. We have previously demonstrated amplification of HER2 in 6 of 33 (18.2%) mucinous ovarian carcinomas (MCs) and presented anecdotal evidence of response with HER2-targeted treatment in a small series of women with recurrent HER2-amplified (HER2+) MC. Here, we explore HER2 amplification and KRAS mutation status in an independent cohort of 189 MCs and 199 mucinous borderline ovarian tumours (MBOTs) and their association to clinicopathological features. HER2 status was assessed by immunohistochemistry (IHC), FISH, and CISH, and interpreted per ASCO/CAP guidelines, with intratumoural heterogeneity assessment on full sections, where available. KRAS mutation testing was performed with Sanger sequencing. Stage and grade were associated with recurrence on both univariate and multivariate analysis (p < 0.001). Assessment of HER2 status revealed overexpression/amplification of HER2 in 29/154 (18.8%) MCs and 11/176 (6.2%) MBOTs. There was excellent agreement between IHC, FISH, and CISH assessment of HER2 status (perfect concordance of HER2 0 or 1+ IHC with non-amplified status, and 3+ IHC with amplified status). KRAS mutations were seen in 31/71 (43.6%) MCs and 26/33 (78.8%) MBOTs, and were near mutually exclusive of HER2 amplification. In the 189 MC cases, a total of 54 recurrences and 59 deaths (53 of progressive disease) were observed. Within MCs, either HER2 amplification/overexpression or KRAS mutation was associated with decreased likelihood of disease recurrence (p = 0.019) or death (p = 0.0041) when compared to cases with neither feature. Intratumoural heterogeneity was noted in 26% of HER2-overexpressing cases. These data support the stratification of MCs for the testing of new treatments, with HER2-targeted therapy as a viable option for HER2+ advanced or recurrent disease. Further research is required to delineate the molecular and clinical features of the ∼34% of MC cases with neither HER2 amplification nor KRAS mutations.

A randomized phase II study investigating the addition of the specific COX-2 inhibitor celecoxib to docetaxel plus carboplatin as first-line chemotherapy for stage IC to IV epithelial ovarian cancer, Fallopian tube or primary peritoneal carcinomas: the DoCaCel study

BACKGROUND

In ovarian cancer, cyclooxygenase-2 (COX-2) overexpression is prognostic for poor survival. We investigated the efficacy of celecoxib (C), a selective COX-2 inhibitor, added to docetaxel (Taxotere)/carboplatin (DC) in advanced ovarian cancer.

PATIENTS AND METHODS

In a phase II, randomized study, 400 mg celecoxib b.i.d. was added to first-line DC treatment (DCC). Celecoxib was to be continued after DC termination up to 3 years. Study end points were tolerability, progression-free survival (PFS) and overall survival (OS).

RESULTS

151 of 196 eligible patients were diagnosed with stage IIIC/IV disease. Median follow-up for patients alive was 32.3 months. Celecoxib was used during a mean of 8.5 months. Twenty-three of 97 DCC patients stopped celecoxib prematurely, mainly due to skin reactions. Complete biochemical response was achieved in 51/78 DC patients (65%) versus 57/78 DCC patients (75%, not significant). In both study arms, median PFS was 14.3 months and median OS 34 months. COX-2 was expressed in 82% of 120 tumor samples retrospectively recovered. The PFS and OS of patients with intermediate/high COX-2 expression were similar to that in the other patients.

CONCLUSION

Celecoxib did not influence PFS and OS, but interpretation of results is hampered by premature celecoxib discontinuation.

Modulation of T cell immune functions by the prostaglandin E(2) - cAMP pathway in chronic inflammatory states

Cyclic AMP is the intracellular second messenger for a variety of immunoregulatory inflammatory mediators such as prostaglandin E2, adenosine and histamine that signal to effector T cells from monocytes, macrophages and regulatory T cells. Protein kinase A (PKA) type I localizes to lipid rafts in effector T cells during T cell activation and directly modulates proximal signal events including phosphorylation of C-terminal Src kinase (Csk), which initiates a negative signal pathway that fine-tunes the T cell activation process. The PKA-Csk immunoregulatory pathway is scaffolded by the A kinase anchoring protein ezrin, the Csk binding protein phosphoprotein associated with glycosphingolipid-enriched membrane microdomains and the linker protein ezrin/radixin/moesin binding protein of 50 kDa. This pathway is hyperactivated in chronic infections with an inflammatory component such as HIV, other immunodeficiencies and around solid tumours as a consequence of local inflammation leading to inhibition of anti-tumour immunity. LINKED ARTICLES This article is part of a themed section on Novel cAMP Signalling Paradigms. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.166.issue-2.

Prognostic biomarkers in ovarian cancer

Epithelial ovarian cancer (EOC) remains the most lethal gynecological malignancy despite several decades of progress in diagnosis and treatment. Taking advantage of the robust development of discovery and utility of prognostic biomarkers, clinicians and researchers are developing personalized and targeted treatment strategies. This review encompasses recently discovered biomarkers of ovarian cancer, the utility of published prognostic biomarkers for EOC (especially biomarkers related to angiogenesis and key signaling pathways), and their integration into clinical practice.

Targeted molecular therapies for ovarian cancer: an update and future perspectives (Review)

Identification of the potential gene expression profiles of epithelial ovarian cancer and the arrival of newly targeted therapies have advanced the strategies used for treatment of this disease. This review focuses on the design of ongoing and planned clinical trials and offers a synopsis of the English-language literature for preclinical and clinical targeted therapies for epithelial ovarian cancer. Among many targeted agents, a promising, novel class of targeted drugs for special patient populations expected to improve the effectiveness of current therapy include inhibitors of angiogenesis, poly (ADP ribose) polymerase (PARP) and DNA repair mechanisms. Inhibition of PARP or homologous recombination (HR) repair mediated by Chk1 (checkpoint kinase 1) would selectively sensitize p53 mutation, BRCAness phenotype (serous type ovarian cancer) or HNF (hepatocyte nuclear factor)-1β-overexpressing tumor cells (clear cell type ovarian cancer) to chemotherapeutic agents. The therapeutic response is likely to be limited to a targeted patient, but not to the broad population. This review discusses some of the key current developments and existing challenges.

Optimizing molecular-targeted therapies in ovarian cancer: the renewed surge of interest in ovarian cancer biomarkers and cell signaling pathways

The hallmarks of ovarian cancer encompass the development of resistance, disease recurrence and poor prognosis. Ovarian cancer cells express gene signatures which pose significant challenges for cancer drug development, therapeutics, prevention and management. Despite enhancements in contemporary tumor debulking surgery, tentative combination regimens and abdominal radiation which can achieve beneficial response rates, the majority of ovarian cancer patients not only experience adverse effects, but also eventually relapse. Therefore, additional therapeutic possibilities need to be explored to minimize adverse events and prolong progression-free and overall response rates in ovarian cancer patients. Currently, a revival in cancer drug discovery is devoted to identifying diagnostic and prognostic ovarian cancer biomarkers. However, the sensitivity and reliability of such biomarkers may be complicated by mutations in the BRCA1 or BRCA2 genes, diverse genetic risk factors, unidentified initiation and progression elements, molecular tumor heterogeneity and disease staging. There is thus a dire need to expand existing ovarian cancer therapies with broad-spectrum and individualized molecular targeted approaches. The aim of this review is to profile recent developments in our understanding of the interrelationships among selected ovarian tumor biomarkers, heterogeneous expression signatures and related molecular signal transduction pathways, and their translation into more efficacious targeted treatment rationales.

Identifying HER2 inhibitors from natural products database

The relationship between abnormal HER2 expression and cancer is important in cancer therapeutics. Formation and spread of cancer cells may be restricted by inhibiting HER2. We conducted ligand-based and structure-based studies to assess the potency of natural compounds as potential HER2 inhibitors. Multiple linear regression (MLR) and support vector machine (SVM) models were constructed to predict biological activities of natural compounds, and molecular dynamics (MD) was used to assess their stability with HER2 under a dynamic environment. Predicted bioactivities of the natural compounds ranged from 6.014–9.077 using MLR (r² = 0.7954) and 5.122–6.950 using SVM (r² = 0.8620). Both models were in agreement and suggest bioactivity based on candidate structure. Conformation changes caused by MD favored the formation of stabilizing H-bonds. All candidates had higher stability than Lapinatib, which may be due to the number and spatial distribution of additional H-bonds and hydrophobic interactions. Amino acids Lys724 and Lys736 are critical for binding in HER2, and Thr798, Cys805, and Asp808 are also important for increased stability. Candidates may block the entrance to the ATP binding site located within the inner regions and prevent downstream activation of HER2. Our multidirectional approach indicates that the natural compounds have good ligand efficacy in addition to stable binding affinities to HER2, and should be potent candidates of HER2 inhibitors. With regard to drug design, designing HER2 inhibitors with carboxyl or carbonyl groups available for H-bond formation with Lys724 and Lys736, and benzene groups for hydrophobic contact with Cys805 may improve protein-ligand stability.

Regulation of polyisoprenylated methylated protein methyl esterase by polyunsaturated fatty acids and prostaglandins

Polyisoprenylation is a set of secondary modifications involving proteins whose aberrant activities are implicated in cancers and degenerative disorders. The last step of the pathway involves an ester-forming polyisoprenylated protein methyl transferase- and hydrolytic polyisoprenylated methylated protein methyl esterase (PMPMEase)-catalyzed reactions. Omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) have been linked with antitumorigeneis and tumorigenesis, respectively. PUFAs are structurally similar to the polyisoprenyl groups and may interfere with polyisoprenylated protein metabolism. It was hypothesized that PUFAs may be more potent inhibitors of PMPMEase than their more polar oxidative metabolites, the prostaglandins. As such, the relative effects of PUFAs and prostaglandins on PMPMEase could explain the association between cyclooxygenase-2 (COX-2) expression in tumors, the chemopreventive effects of the non-steroidal anti-inflammatory (NSAIDs) COX-2 inhibitors and PUFAs. PUFAs such as arachidonic (AA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids inhibited PMPMEase activity with Ki values of 0.12 to 3.7 μM. The most potent prostaglandin was 63-fold less potent than AA. The PUFAs were also more effective at inducing neuroblastoma cell death at physiologically equivalent concentrations. The lost PMPMEase activity in AA-treated degenerating cells was restored by incubating the lysates with COX-1 or COX-2. PUFAs may thus be physiological regulators of cell growth and could owe these effects to PMPMEase inhibition.

Dual-colour HER2/chromosome 17 chromogenic in situ hybridisation enables accurate assessment of HER2 genomic status in ovarian tumours

BACKGROUND

Ovarian cancer is a leading cause of gynaecological cancer-related morbidity and mortality. There has been increasing interest in the potential utility of anti-human epidermal growth factor receptor 2 (anti-HER2) agents in the treatment of this disease, with the attendant need to identify suitable predictive biomarkers of response to treatment.

AIMS/METHODS

The authors studied the prevalence of HER2 genomic amplification and overexpression in 85 ovarian tumours in the local patient cohort of this study, as well as the concordance rate between immunohistochemistry, fluorescent in situ hybridisation (FISH) and a dual-colour HER2/chromosome 17 centromere chromogenic in situ hybridisation (CISH) assay.

RESULTS

The authors identified HER2 genomic amplification and protein overexpression in 35.3% (6/17) and 29.4% (5/17), respectively, of primary ovarian mucinous carcinomas. No other cancer subtypes displayed HER2 amplification or protein overexpression. The authors also found a perfect concordance between FISH and dual-colour CISH analysis (κ coefficient 1.0, p<0.001).

CONCLUSION

The results of this study support existing reports that HER2 genomic amplification and protein overexpression are predominantly found in primary ovarian mucinous carcinomas. Given the perfect concordance between the FISH and dual-colour CISH assays and the advantages of CISH over FISH analysis, future clinical trials investigating the use of anti-HER2 therapeutics in ovarian carcinomas should incorporate dual-colour CISH as part of the HER2 status assessment algorithm.

Angiogenesis and molecular markers in advanced epithelial ovarian cancer: a retrospective study

OBJECTIVE

The role of molecular markers in ovarian cancer is still a matter of debate. Angiogenesis is a necessary condition for tumor growth. Hypoxia induces angiogenesis, and cyclooxygenase-2 (COX-2), p53 and HER2 are involved in cancer proliferation and angiogenesis regulation. The aims of this study were to evaluate the relationship between intratumoral microvessel density (IMD) and the expression of molecular markers that affect angiogenesis (COX-2, p53 and HER2) in advanced epithelial ovarian cancer (EOC), to analyze their prognostic and predictive value and their association with clinicopathological features, such as serum hemoglobin level at diagnosis (Hb).

METHODS

Immunohistochemical staining with CD34 (for IMD), COX-2, p53 and HER2 antibodies was performed in 113 patients with advanced EOC who had undergone primary surgery. Clinicopathological data were collected and statistical analyses were performed.

RESULTS

Neither IMD, COX-2 nor HER2 had any predictive or prognostic value in EOC. A relationship that approached statistical significance was found between p53 expression and a complete response to treatment (p=0.05). p53 expression and tumor grade were inversely associated (p=0.012). Hb<12g/dl had predictive value (p=0.02).

CONCLUSIONS

In our series IMD, COX-2 and HER2 had neither prognostic nor predictive value in advanced EOC. p53 and Hb may be predictive factors. The results and clinical usefulness of immunohistochemistry are controversial. Further evaluations are required to determine whether the serum levels of molecular markers correlate with the results of immunohistochemical assays and whether they offer any prognostic and/or predictive value. Targeted therapy remains the ultimate goal of these studies.

Prognostic impact of prechemotherapy serum levels of HER2, CA125, and HE4 in ovarian cancer patients

OBJECTIVE

Human epididymis protein 4 (HE4) has attracted a lot of interest as a relatively novel biomarker for ovarian carcinoma. Research focus has been directed at HE4 as a diagnostic tool with potential for better triage of women with adnexal masses but the prognostic aspect of HE4 in ovarian cancer patients remains to be elucidated. The aim of the present study was to investigate the prognostic value of prechemotherapy serum HER2, cancer antigen 125 (CA125), and HE4 levels in ovarian cancer patients receiving standard combination chemotherapy.

METHODS

Serum from 139 patients with newly diagnosed ovarian cancer was analyzed for HER2, CA125, and HE4 using enzyme-linked immunosorbent assay assays. Samples were collected just before first-line chemotherapy, and all patients were treated with carboplatin-paclitaxel combination chemotherapy.

RESULTS

Increasing levels of serum HE4 (grouped into quartiles) was significantly associated with worse progression-free survival (PFS) (P < 10) and overall survival (P < 10). After adjustment in the Cox model, HE4 serum levels remained an independent prognostic parameter for PFS, with a hazard ratio of 1.77 (95% confidence interval, 1.03-3.04; P = 0.040) for patients with HE4 levels above the median compared with patients with HE4 levels below the median. The shorter PFS for patients with high levels of HE4 also translated into an independent significant difference in overall survival (hazard ratio, 3.17 [95% confidence interval, 1.41-7.10]; P = 0.005).Serum HER2 and CA125 levels did not demonstrate an independent prognostic value.

CONCLUSIONS

High levels of serum HE4 is a strong and independent indicator of worse prognosis in epithelial ovarian cancer patients.

Serological and immunohistochemical HER-2/neu statuses do not correlate and lack prognostic value for ovarian cancer patients

The serodiagnostics of extracellular domain (ECD) HER-2/neu has turned into an evidenced-based tumour marker for HER-2/neu-positive breast cancer patients. This study investigated the clinical relevance of immunohistochemical and serum HER-2/neu in 44 patients with advanced ovarian cancer. The Hercept-Test® from DAKO Diagnostics was used to analyse immunohistochemical HER-2/neu expression. The HER-2/neu ECD in serum was determined quantitatively by Bayer Immuno 1™ Immunoanalyser. The HER-2/neu serum values were correlated to the clinical course of disease and to established prognostic factors, i.e. progression-free and overall survival. Some 23% of patients (n = 11) expressed HER-2/neu serum levels higher than 15 ng/mL, whereas only 7.7% (n = 2) of the patients examined by immunohistochemistry showed a HER-2/neu overexpression of the tissue. None of them revealed an overexpression of HER-2/neu ECD by serodiagnostics. HER-2/neu overexpression did not correlate significantly to any of the analysed prognostic factors. According to progression-free and overall survival, there was no significant difference between serologically HER-2/neu-positive or negative patients. For ovarian cancer patients, neither high HER-2/neu serum levels, nor immunohistochemically determined HER-2/neu positivity, appear to predict the course of disease. This study shows a lack of association between the immunohistochemical HER-2/neu status and the serum level of solute extracelluar HER-2/neu domain.

Cyclic AMP-mediated immune regulation--overview of mechanisms of action in T cells

The canonical second messenger cAMP is well established as a potent negative regulator of T cell immune function. Through protein kinase A (PKA) it regulates T cell function at the level of transcription factors, members of the mitogen-activated protein kinase pathway, phospholipases (PLs), Ras homolog (Rho)A and proteins involved in the control of cell cycle progression. Type I PKA is the predominant PKA isoform in T cells. Furthermore, whereas type II PKA is located at the centrosome, type I PKA is anchored close to the T cell receptor (TCR) in lipid rafts by the Ezrin-ERM-binding phosphoprotein of 50 kDa (EBP50)-phosphoprotein associated with glycosphingolipid-enriched microdomains (PAG) scaffold complex. The most TCR-proximal target for type I PKA is C-terminal Src kinase (Csk), which upon activation by raft recruitment and phosphorylation inhibits the Src family tyrosine kinases Lck and Fyn and thus functions to maintain T cell homeostasis. Recently, induction of cAMP levels in responder T cells has emerged as one of the mechanisms by which regulatory T (T(R)) cells execute their suppressive action. Thus, the cAMP-type I PKA-Csk pathway emerges as a putative target for therapeutic intervention in autoimmune disorders as well as in cancer, where T(R) cell-mediated suppression contributes to suboptimal local immune responses.

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.

The role of HER2 in cancer therapy and targeted drug delivery

HER2 is highly expressed in a significant proportion of breast cancer, ovarian cancer, and gastric cancer. Since the discovery of its role in tumorigenesis, HER2 has received great attention in cancer research during the past two decades. Successful development of the humanized monoclonal anti-HER2 antibody (Trastuzumab) for the treatment of breast cancer further spurred scientists to develop various HER2 specific antibodies, dimerization inhibitors and kinase inhibitors for cancer therapy. On the other hand, the high expression of HER2 and the accessibility of its extracellular domain make HER2 an ideal target for the targeted delivery of anti-tumor drugs as well as imaging agents. Although there is no natural ligand for HER2, artificial ligands targeting HER2 have been developed and applied in various targeted drug delivery systems. The emphasis of this review is to elucidate the roles of HER2 in cancer therapy and targeted drug delivery. The structure and signal pathway of HER2 will be briefly described. The role of HER2 in tumorigenesis and its relationship with other tumor markers will be discussed. For the HER2 targeted cancer therapy, numerous strategies including the blockage of receptor dimerization, inhibition of the tyrosine kinase activity, and interruption of the downstream signal pathway will be summarized. For the targeted drug delivery to HER2 positive tumor cells, various targeting ligands and their delivery systems will be described in details.

Cyclooxygenase-2 inhibition inhibits PI3K/AKT kinase activity in epithelial ovarian cancer

Cyclooxygenase-2 (COX-2) expression contributes to tumor growth and invasion in epithelial ovarian cancer (EOC). COX-2 inhibitors exhibit important anticarcinogenic potential against EOC, but the molecular mechanisms underlying this effect and relation with PI3-kinase/AKT signaling remain the subject of intense investigations. Therefore, the role of COX-2 in EOC and its cross talk with PI3-kinase/AKT pathway were investigated using a large series of EOC tissues in a tissue micro array (TMA) format followed by in vitro and in vivo studies using EOC cell lines and NUDE mice. Clinically, COX-2 was overexpressed in 60.3% of EOC and was significantly associated with activated AKT (p < 0.0001). Cox-1 expression was seen in 59.9% but did not associate with AKT. Our in vitro data using EOC cell line showed that inhibition of COX-2 by aspirin, selective inhibitor NS398 and gene silencing by COX-2 specific siRNA impaired phosphorylation of AKT resulting decreased downstream signaling leading to cell growth inhibition and induction of apoptosis. Finally, treatment of MDAH2774 cell line xenografts with aspirin resulted in growth inhibition of tumors in NUDE mice via down-regulation of COX-2 and AKT activity. These data identify COX-2 as a potential biomarker and therapeutic target in distinct molecular subtypes of ovarian cancer.

Inhibition of functional HER family members increases the sensitivity to docetaxel in human ovarian cancer cell lines

Human epidermal growth factor (HER) family-targeted therapy combined with standard cytotoxic agents might improve the treatment of ovarian cancer. Human ovarian cancer cell lines OVCAR-3, IGROV-1, and SKOV-3 with differential EGFR, HER2, and HER3 expression levels were used to study whether EGFR-directed (cetuximab) or HER2-directed (trastuzumab, pertuzumab) monoclonal antibodies inhibited cell growth and abrogated activated receptor signaling routes. Possible increase of antiproliferative effects and further activation of caspase-3 as a read-out for apoptosis were analyzed when monoclonal antibodies were combined with docetaxel. Cetuximab alone inhibited cell growth in OVCAR-3 and IGROV-1, which was more pronounced when combined with pertuzumab in OVCAR-3. SKOV-3 cell growth was not significantly affected by any of the antibodies. Cetuximab increased the 50% growth-inhibiting effects of docetaxel in OVCAR-3 and IGROV-1, but not in SKOV-3. Coaddition of pertuzumab to cetuximab plus docetaxel in OVCAR-3 and IGROV-1, and, to a lesser extent trastuzumab in OVCAR-3, inhibited cell growth even further. Caspase-3 activation by docetaxel was enhanced after addition of cetuximab in OVCAR-3 and after addition of cetuximab plus pertuzumab in IGROV-1 and SKOV-3. Functional EGFR-signaling, HER2-signaling, and HER3-signaling routes as shown from abrogation of EGF-stimulated and heregulin-stimulated phosphorylated ERK1/2 by cetuximab, trastuzumab, and pertuzumab, respectively, were shown in OVCAR-3 and IGROV-1, but hardly in SKOV-3. Pertuzumab was able to abrogate phosphorylated HER2 by EGF and heregulin, except in SKOV-3. In conclusion, a combination of docetaxel with inhibitors of HER family members, such as cetuximab plus pertuzumab, may be considered for a clinical trial in ovarian carcinomas with functional receptors.

Cyclooxygenase-2 expression and connection with tumor recurrence and histopathologic parameters in gastrointestinal stromal tumors

Tissue cyclooxygenase-2 (COX-2) is a rate-limiting enzyme in prostaglandin synthesis and has been shown to have roles in carcinogenesis and tumor progression. Evaluation of COX-2 overexpression in malignancies has been performed mostly on tumors of epithelial origin, and little is known about its presence in mesenchymal tumors, especially gastrointestinal stromal tumors (GIST). COX-2 has been reported to be widely expressed in GIST and has been suggested as a potential diagnostic marker. We evaluated the overexpression and roles of COX-2 in tumorigenesis in GIST with regard to its relation to prognostic parameters and tumor recurrence. We studied the presence of COX-2 expression immunohistochemically and its relation to clinicopathologic prognostic variables in 41 cases of GIST. COX-2 was overexpressed in 21 (51%) of 41 tumors. The extent of overexpression was greater in tumors that recurred after surgical resection. COX-2 overexpression was also higher in tumors with coagulative necrosis, high mitotic index and an infiltrative pattern of growth. The observation of greater COX-2 expression levels in GIST with unfavorable histopathologic variables is contrary to previous reports and consistent with the reported roles of COX-2 in carcinogenesis of epithelial malignancies.

Tumor immunosuppressive environment: effects on tumor-specific and nontumor antigen immune responses

The interactions between cancer cells and host immune cells in tumoral microenvironments create an immunosuppressive network that promotes tumor growth, protects the tumor from immune attack and attenuates the efficacy of immunotherapeutic approaches. The development of immune tolerance becomes predominant in the immune system of patients with advanced-stage tumors. Several mechanisms have been described by which tumors can suppress the immune system, including secretion of cytokines, alterations in antigen-presenting cell subsets, costimulatory and coinhibitory molecule alterations and altered ratios of Tregs to effector T cells. It is well demonstrated that these mechanisms of immunosuppression can impair tumor specific immune responses. However, it is not well established whether this immunosuppressive environment can affect immune responses to nontumor antigens, specifically in regard to priming and the development of memory. The few existing studies indicate that responses to nontumor antigens seem unaffected, although there is still a deep lack of understanding of this phenomenon. This is an important issue regarding patient endurance and quality of life. Here, we review the existing evidence on immunosuppression promoted by tumors, with particular attention to its impact on specific immune responses. Understanding these interactions can help us subvert tumor-induced tolerance and optimize anti-tumor therapy.

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.

miR-29b expression is associated with disease-free survival in patients with ovarian serous carcinoma

Micro-RNAs are a group of small noncoding RNAs approximately 22 nucleotides in length. Recent work has shown differential expression of mature micro-RNAs in human cancers. We characterized the alteration in expression of miR-29b in ovarian serous carcinoma. miR-29b expression was analyzed using quantitative stem-loop reverse transcriptase polymerase chain reaction on a set of 50 formalin-fixed, paraffin-embedded ovarian serous carcinoma samples. Protein expression of p53, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, Ki-67, and insulinlike growth factor 1 was quantified in the corresponding tissue microarray. The expression profile of miR-29b was correlated with clinicopathological and patient survival data. We provide definitive evidence that miR-29b is down-regulated in a significant proportion of ovarian serous carcinomas and is associated with specific clinicopathological features, most notably high miR-29b expression being associated with reduced disease-free survival.