Targeted therapies in epithelial ovarian cancer. J Oncol. 2010;2010:314326. [PMID: 20111741 PMCID: PMC2810474 DOI: 10.1155/2010/314326]

Endostar Plus Apatinib Successfully Achieved Long Term Progression-Free Survival in Refractory Ovarian Cancer: A Case Report and Literature Review

Background

Ovarian cancer (OC) is a common malignancy in the gynecological tumor. Standard treatment for ovarian cancer is surgery and chemotherapy based on paclitaxel and platinum. However, traditional chemotherapy for ovarian cancer is limited by drug resistance and systemic side effects. It is imperative to explore effective treatment options for refractory ovarian cancer.

Case Presentation

A 52-year-old female initially presented with lower abdominal distension and migratory pain. After the laparoscopic exploration and biopsy, immunohistochemistry showed poorly differentiated adenocarcinoma originated from ovarian (cT3NxM1, stage IV, peritoneal and abdominal wall metastasis). The next generation sequence detected ERRFI1 (T187A, exon4) mutation.

Results

The patient received first-line chemotherapy (paclitaxel, nedaplatin plus avastin), followed by maintenance therapy with gefitinib, achieving a 15-month progression-free survival (PFS). After disease progression and second-line treatment failure, endostar plus apatinib was administered for 14 cycles and she obtained a PFS of 14 months without long-term adverse events.

Conclusion

We believe that the ERRFI1 gene may be a potential target of gefitinib. Importantly, endostar combined with apatinib is worth recommending for maintenance treatment in refractory ovarian cancer.

Gentisyl Alcohol Inhibits Proliferation and Induces Apoptosis via Mitochondrial Dysfunction and Regulation of MAPK and PI3K/AKT Pathways in Epithelial Ovarian Cancer Cells

Ovarian cancer is one of the prevalent gynecological cancers occurring in women. In particular, the efficiency of standard therapeutic methods decreases when recurrence and chemoresistance ensue. To assist standard anti-cancer agents in the cure of ovarian cancer, development and application of new compounds such as small molecules or natural products are required. Gentisyl alcohol is one of the secondary metabolites that can be obtained by purification from bacteria or fungi and is known to have antibacterial, antifungal, antiviral, and anti-cancer effects. In the present study, we verified the effect of gentisyl alcohol derived from marine Arthrinium sp. on suppressing proliferation and inducing apoptosis via DNA fragmentation in human ovarian cancers cells (ES2 and OV90 cells). We also confirmed that there was an accumulation of sub-G1 cells and a loss of mitochondrial membrane potential with calcium dysregulation in gentisyl alcohol-treated ovarian cancer cells. Moreover, gentisyl alcohol up-regulated signal transduction of MAPK and PI3K/AKT pathways. Collectively, our results demonstrated the possibility of gentisyl alcohol as a novel therapeutic agent for human ovarian cancer.

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.

Extracellular vesicles in ovarian cancer: applications to tumor biology, immunotherapy and biomarker discovery

In recent years there has been tremendous interest in both the basic biology and applications of extracellular vesicles (EVs) in translational cancer research. This includes a better understanding of their biogenesis and mechanisms of selective cargo packaging, their precise roles in horizontal communication, and their application as non-invasive biomarkers. The rapid advances in next-generation omics technologies are the driving forces for these discoveries. In this review, the authors focus on recent results of EV research in ovarian cancer. A deeper understanding of ovarian cancer-derived EVs, the types of cargo molecules and their biological roles in cancer growth, metastases and drug resistance, could have significant impact on the discovery of novel biomarkers and innovative therapeutics. Insights into the role of EVs in immune regulation could lead to novel approaches built on EV-based immunotherapy.

Pattern of triple negative epithelial ovarian cancer in indigenous African women

Background: Triple negative epithelial ovarian cancer (TNEOC)  refers to ovarian carcinomas that do not express estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor- type 2 (HER-2/neu).  The aim of this study is to determine the pattern of triple negative epithelial ovarian cancer in indigenous African women.

Methods: We performed a retrospective review of ER, PR and HER-2/neu expression in 90 Nigerian patients with histologically diagnosed epithelial ovarian cancer. Lack of expression of ER, PR and HER2/neu antigens was used to determine carcinomas that are among the TNEOC. We also compared the clinicopathological parameters (age, International Federation of Gynaecology and Obstetrics (FIGO) stage, grade and histological subtype) in patients with TNEOC and non- TNEOC .

Results: Thirty-eight (42.2%) of the 90 tumours diagnosed as EOC were negative for ER, PR and HER2/neu expression. There was no significant association between TNEOC with other parameters such as age, FIGO stage and histological grade. Sixteen (66.7%) of the 24 mucinous carcinomas were triple negative, while only 21 (33.3%) of the 63 serous carcinomas were triple-negative and one (50%) of the two endometrioid carcinomas was triple negative. There was a significant association between triple-negative tumours and histological subtypes of EOC (p = 0.034).

Conclusions: A subtype of epithelial ovarian cancer that is negative for ER, PR and HER-2/neu has been discovered in indigenous African women. TNEOC expression is high and is comparable to the triple negative breast cancer subtype seen in people of African ancestry. Future study of TNEOC in a large sample size should be considered.

High incidence of ErbB3, ErbB4, and MET expression in ovarian cancer

Ovarian cancer is the leading cause of death from gynecologic cancers in the United States. Failure may be due to variable expression and/or complex interactions of growth factor receptors in individual tumors. As ErbB3-MET cooperativity is implicated in solid tumor resistance to EGFR/ErbB2 inhibitors, we evaluated expression of MET and all 4 ErbB family members in ovarian cancers. Tissue arrays were prepared from archival formalin-fixed paraffin-embedded tumor samples, including 202 ovarian carcinomas (Stage I-IV) and controls. Of 202 patient samples, only 25% were positive for EGFR and 35% for ErbB2 expression. ErbB3, ErbB4, and MET showed marked expression in 76%, 98%, and 96% of cases. Consistent with high incidence, there was no significant correlation for expression of ErbB3, ErbB4, or MET with outcome. On the basis of their high expression in the majority of cases, inhibitors targeting ErbB3, ErbB4, and/or MET may be broadly applicable as therapeutic agents in this disease.

Downregulation of miR-130a contributes to cisplatin resistance in ovarian cancer cells by targeting X-linked inhibitor of apoptosis (XIAP) directly

MicroRNAs (miRNAs) are short, highly conserved small non-coding RNA molecules, which post-transcriptionally regulate genes expression and play crucial roles in diverse biological processes. Recent studies have shown that dysregulation of miRNAs might modulate the resistance of cancer cells to chemotherapeutic agents. To investigate the possible role of miR-130a in the development of cisplatin resistance in human ovarian cancer cell line A2780, we evaluated the expression of microRNA-130a (miR-130a) in the cells by the quantitative real-time reverse transcription-polymerase chain reaction. The results showed that miR-130a was significantly down-regulated in cisplatin-resistant ovarian cancer cells. MTT assay and flow cytometry (FCM) results showed that over-expression of miR-130a regulated apoptotic activity, and thereby cisplatin chemosensitivity, in ovarian cancer cells. Furthermore, we found that miR-130a can directly target XIAP, and participate in the regulation of apoptosis. The up-regulation of miR-130a led to a significant decrease in the XIAP mRNA levels and protein levels. XIAP plays an important role in cisplatin resistance in ovarian cancer cell line A2780. Our findings suggested that miR-130a could play a role in the development of cisplatin resistance in ovarian cancer cell line A2780, at least in part by modulation of apoptosis via targeting XIAP.

Identification of the IGF1/PI3K/NF κB/ERK gene signalling networks associated with chemotherapy resistance and treatment response in high-grade serous epithelial ovarian cancer

BACKGROUND

Resistance to platinum-based chemotherapy remains a major impediment in the treatment of serous epithelial ovarian cancer. The objective of this study was to use gene expression profiling to delineate major deregulated pathways and biomarkers associated with the development of intrinsic chemotherapy resistance upon exposure to standard first-line therapy for ovarian cancer.

METHODS

The study cohort comprised 28 patients divided into two groups based on their varying sensitivity to first-line chemotherapy using progression free survival (PFS) as a surrogate of response. All 28 patients had advanced stage, high-grade serous ovarian cancer, and were treated with standard platinum-based chemotherapy. Twelve patient tumours demonstrating relative resistance to platinum chemotherapy corresponding to shorter PFS (< eight months) were compared to sixteen tumours from platinum-sensitive patients (PFS > eighteen months). Whole transcriptome profiling was performed using an Affymetrix high-resolution microarray platform to permit global comparisons of gene expression profiles between tumours from the resistant group and the sensitive group.

RESULTS

Microarray data analysis revealed a set of 204 discriminating genes possessing expression levels which could influence differential chemotherapy response between the two groups. Robust statistical testing was then performed which eliminated a dependence on the normalization algorithm employed, producing a restricted list of differentially regulated genes, and which found IGF1 to be the most strongly differentially expressed gene. Pathway analysis, based on the list of 204 genes, revealed enrichment in genes primarily involved in the IGF1/PI3K/NF κB/ERK gene signalling networks.

CONCLUSIONS

This study has identified pathway specific prognostic biomarkers possibly underlying a differential chemotherapy response in patients undergoing standard platinum-based treatment of serous epithelial ovarian cancer. In addition, our results provide a pathway context for further experimental validations, and the findings are a significant step towards future therapeutic interventions.

Influence of CYP3A4 genotypes in the outcome of serous ovarian cancer patients treated with first-line chemotherapy: implication of a CYP3A4 activity profile

CYP3A4 is a key enzyme involved in the metabolism of numerous compounds, such as paclitaxel, and its activity shows an extensive inter-individual variation which can influence treatment response. The study's purpose was to investigate the potential predictive role of a CYP3A4 profile (CYP3A4*1B, rs2740574 and CYP3A4*22, rs35599367) in serous ovarian cancer patients treated with first-line chemotherapy (paclitaxel and cisplatin or carboplatin), after cytoreductive surgery. CYP3A4*1B and CYP3A4*22 genotypes were determined by Nested PCR-RFLP and Taqman® Allelic Discrimination, respectively. We observed that the mean survival rates were statistically different according the patients CYP3A4 genotypes. The group of patients carrying the CYP3A4*1B G allele present a decreased mean survival rate when compared with AA genotype patients (103.93 and 134.44 months, respectively, p = 0.010). This result is consistent after multivariate Cox regression analysis (HR, 2.15; 95% CI, 1.03-4.52; p = 0.043). The combination of CYP3A4*1B and CYP3A4*22 polymorphisms result in the definition of a CYP3A4 activity profile: the group of patients with a higher CYP3A4 activity profile had significantly diminished survival when compared with patients with a lower CYP3A4 activity profile (101.06 and 134.44 months, respectively, p = 0.012). Multivariate Cox regression analysis revealed a diminished overall survival time for patients with CYP3A4 high activity profile (HR, 2.29; 95% CI, 1.05-5.02; p = 0.038). The definition of a CYP3A4 activity profile resulted in the increase of prediction ability, using Harrels's concordance indexes (C-index from 0.617 to 0.626). To conclude, our results demonstrate an association between CYP3A4*1B and a diminished overall survival of patients with serous ovarian cancer. The definition of a CYP3A4 activity profile proved to be benefic and the CYP3A4 high activity profile was associated with a lower overall survival. We consider that the definition of a CYP3A4 activity profile might be useful as molecular marker for predicting the clinical outcome of serous ovarian cancer patients.

Ovarian cancer and DNA repair: DNA ligase IV as a potential key

Ovarian cancer (OC) is the sixth most common cancer and the seventh cause of death from cancer in women. The etiology and the ovarian carcinogenesis still need clarification although ovulation may be determinant due to its carcinogenic role in ovarian surface epithelium. The link between ovarian carcinogenesis and DNA repair is well established and it became clear that alterations in DNA damage response may affect the risk to develop OC. Polymorphisms are variations in the DNA sequence that exist in normal individuals of a population and are capable to change, among other mechanisms, the balance between DNA damage and cellular response. Consequently, genetic variability of the host has a great role in the development, progression and consequent prognosis of the oncologic patient as well as in treatment response. Standard treatment for OC patients is based on cytoreductive surgery, followed by chemotherapy with a platinum agent and a taxane. Although 80% of the patients respond to the first-line therapy, the development of resistance is common although the mechanisms underlying therapy failure remain mostly unknown. Because of their role in oncology, enzymes involved in the DNA repair pathways, like DNA Ligase IV (LIG4), became attractive study targets. It has been reported that variations in LIG4 activity can lead to a hyper-sensitivity to DNA damage, deregulation of repair and apoptosis mechanisms, affecting the susceptibility to cancer development and therapy response. To overcome resistance mechanisms, several investigations have been made and the strategy to target crucial molecular pathways, such as DNA repair, became one of the important areas in clinical oncology. This review aims to elucidate the link between DNA repair and OC, namely which concerns the role of LIG4 enzyme, and how genetic polymorphisms in LIG4 gene can modulate the activity of the enzyme and affect the ovarian carcinogenesis and treatment response. Moreover, we try to understand how LIG4 inhibition can be a potential contributor for the development of new cancer treatment strategies.

Regulation of macroautophagy in ovarian cancer cells in vitro and in vivo by controlling glucose regulatory protein 78 and AMPK

In this study we show that diindolylmethane (DIM) induces autophagy in ovarian cancer cells by regulating endoplasmic reticulum (ER) stress and AMPK. Treatment of SKOV-3, OVCAR-3 and TOV-21G ovarian cancer cells with varying concentrations of DIM for 24 hours resulted in a concentration dependent induction of autophagy as measured by flowcytometry. Electron microscopy confirmed the presence of autophagosomes in DIM treated cells. Western blot analysis showed that DIM treatment increased the expression of LC3B, a hall mark of autophagy as well as p62 and Atg 12 proteins that are accumulated during autophagy. Autophagy inhibitors bafilomycin or chloroquine inhibited DIM induced autophagy. Furthermore, DIM treatment significantly increased the expression of ER stress regulators such as Grp78, IRE1 and GADD153. Cycloheximide or ER stress inhibitor mithramycin not only blocked ER stress proteins that were activated by DIM but also autophagy. Silencing Grp78 or GADD 153 significantly blocked the expression of LC3B and p62 indicating that autophagy in our model is mediated by ER stress. Knocking out LC3B inhibited DIM induced autophagy. DIM treatment increased the cytosolic calcium levels which lead to the activation of AMPK in our model. Chelating cytosolic calcium with BAPT-AM abrogated not only the phosphorylation of AMPK but also prevented DIM induced autophagy. Inhibiting AMPK by a chemical inhibitor or siRNA blocked the induction of LC3B or p62, indicating that DIM mediated autophagy requires activation of AMPK. Oral administration of DIM significantly suppressed SKOV-3 tumor xenografts in nude mice. Activation of ER stress and autophagy were observed in the tumors of DIM treated mice. Taken together, these results suggest that induction of autophagy by DIM in ovarian cancer cells was associated with ER stress and AMPK activation.

Inhibition of EGFR-AKT axis results in the suppression of ovarian tumors in vitro and in preclinical mouse model

Ovarian cancer is the leading cause of cancer related deaths in women. Genetic alterations including overexpression of EGFR play a crucial role in ovarian carcinogenesis. Here we evaluated the effect of phenethyl isothiocyanate (PEITC) in ovarian tumor cells in vitro and in vivo. Oral administration of 12 µmol PEITC resulted in drastically suppressing ovarian tumor growth in a preclinical mouse model. Our in vitro studies demonstrated that PEITC suppress the growth of SKOV-3, OVCAR-3 and TOV-21G human ovarian cancer cells by inducing apoptosis in a concentration-dependent manner. Growth inhibitory effects of PEITC were mediated by inhibition of EGFR and AKT, which are known to be overexpressed in ovarian tumors. PEITC treatment caused significant down regulation of constitutive protein levels as well as phosphorylation of EGFR at Tyr1068 in various ovarian cancer cells. In addition, PEITC treatment drastically reduced the phosphorylation of AKT which is downstream to EGFR and disrupted mTOR signaling. PEITC treatment also inhibited the kinase activity of AKT as observed by the down regulation of p-GSK in OVCAR-3 and TOV-21G cells. AKT overexpression or TGF treatment blocked PEITC induced apoptosis in ovarian cancer cells. These results suggest that PEITC targets EGFR/AKT pathway in our model. In conclusion, our study suggests that PEITC could be used alone or in combination with other therapeutic agents to treat ovarian cancer.

Biologic therapies and personalized medicine in gynecologic malignancies

Through advances in human genomic sequencing, the unique molecular biology that predisposes certain individuals to either health or disease has now been illuminated. Although many malignancies behave similarly on a phenotypic level, biologically there exist multiple layers of interconnected molecular and cellular pathways that may make each patient’s disease significantly more unique than previously appreciated. In gynecologic oncology, the most progress in developing targeted biologics has been in the treatment of ovarian cancers. Future investigations will see further development in endometrial and cervical cancers. Technology such as whole genome sequencing can theoretically identify the individual tumor’s genetic profile; however, identifying the priority pathways for therapeutic interventions and subsequent complex interactions remains a significant challenge. New therapeutic technologies such as siRNA and immune modulators will also play a promising role in the movement toward individualized therapies. It is hoped that the identification and use of targeted agents will lead to individualized care that in turn will lead to significantly improved outcomes manifested by more cures and better quality of life through amelioration of toxicities.

EGFR/HER-targeted therapeutics in ovarian cancer

Despite decades of research and evolving treatment modalities, survival among patients with epithelial ovarian cancer has improved only incrementally. During this same period, the development of biologically targeted therapeutics has improved survival for patients with diverse malignancies. Many of these new drugs target the human epidermal growth factor receptor (EGFR/HER/ErbB) family of tyrosine kinases, which play a major role in the etiology and progression of many carcinomas, including epithelial ovarian cancer. While several HER-targeted therapeutics are US FDA approved for the treatment of various malignancies, none have gained approval for the treatment of ovarian cancer. Here, we review the published literature on HER-targeted therapeutics for the treatment of ovarian cancer, including novel HER-targeted therapeutics in various stages of clinical development, as well as the challenges that have limited the use of these inhibitors in clinical settings.

Blocking epidermal growth factor receptor activation by 3,3'-diindolylmethane suppresses ovarian tumor growth in vitro and in vivo

Genetic alterations, including the overexpression of epidermal growth factor receptor (EGFR) (in approximately 70% of ovarian tumors), play a crucial role in the signal transduction pathways that regulate key cellular functions, such as cell survival and proliferation, and are responsible for compromising traditional chemotherapy. 3,3'-Diindolylmethane (DIM) is an indole compound present in Brassica vegetables. In our previous studies, we demonstrated that BR-DIM, a formulated version of DIM, suppressed the growth of ovarian cancer cells by causing cell cycle arrest and apoptosis. In the present study, we delineated the mechanism by which DIM suppressed the growth of SKOV-3, OVCAR-3, and TOV-21G human ovarian cancer cells. DIM treatment caused significant down-regulation of the constitutive EGFR protein level as well as phosphorylation of EGFR at Tyr1068, Tyr992, Tyr845, and Tyr1173 in various ovarian cancer cells. To determine whether DIM suppressed the activation of EGFR by activating phosphorylation, cells were treated with epidermal growth factor. Epidermal growth factor treatment significantly blocked the DIM-mediated inhibition of EGFR activation and apoptosis in both SKOV-3 and OVCAR-3 cells. In addition, DIM treatment drastically reduced the phosphorylation of mitogen-activated protein kinase kinase (MEK) and extracellular signal-regulated kinase (ERK), which are downstream to EGFR, without affecting their protein levels. DIM treatment also inhibited the kinase activity of ERK, as observed by the down-regulation of phospho-E twenty-six like transcription factor 1 (p-ELK1) in all three ovarian cancer cell lines. DIM significantly suppressed the growth of ovarian tumors in vivo. Tumor growth suppressive effects of DIM in SKOV-3 tumor xenografts were associated with reduced phosphorylation of EGFR, MEK, and ERK. These results indicate that DIM induces apoptosis in ovarian cancer cells by inhibiting the EGFR-ERK pathway in vitro and in vivo.

Utility of vascular endothelial growth factor inhibitors in the treatment of ovarian cancer: from concept to application

Despite recent advances in the management of ovarian cancer, it remains the most lethal gynecologic malignancy. Vascular endothelial growth factor (VEGF) has been shown to play a pivotal role in the progression of ovarian cancer leading to the eventual development of malignant ascites. On this basis, agents rendering VEGF ineffective by neutralizing VEGF (bevacizumab), blocking its receptors (aflibercept), or interfering with the postreceptor signaling pathways (sunitinib) provide us with the rational treatment options. These agents are generally used in combination with the standard chemotherapeutic drugs. Here, we discuss the basis of and the logic behind the use of these agents in the treatment of epithelial ovarian cancer, as well as their evaluation in different preclinical and clinical studies.