Engineering Bifunctional Calcium Alendronate Gene-Delivery Nanoneedle for Synergistic Chemo/Immuno-Therapy Against HER2 Positive Ovarian Cancer

Ovarian cancer is the most lethal gynecological malignancy. Most patients are diagnosed at an advanced stage with widespread peritoneal dissemination and ascites. Bispecific T-cell engagers (BiTEs) have demonstrated impressive antitumor efficacy in hematological malignancies, but the clinical potency is limited by their short half-life, inconvenient continuous intravenous infusion, and severe toxicity at relevant therapeutic levels in solid tumors. To address these critical issues, the design and engineering of alendronate calcium (CaALN) based gene-delivery system is reported to express therapeutic level of BiTE (HER2×CD3) for efficient ovarian cancer immunotherapy. Controllable construction of CaALN nanosphere and nanoneedle is achieved by the simple and green coordination reactions that the distinct nanoneedle-like alendronate calcium (CaALN-N) with a high aspect ratio enabled efficient gene delivery to the peritoneum without system in vivo toxicity. Especially, CaALN-N induced apoptosis of SKOV3-luc cell via down-regulation of HER2 signaling pathway and synergized with HER2×CD3 to generate high antitumor response. In vivo administration of CaALN-N/minicircle DNA encoding HER2×CD3 (MC-HER2×CD3) produces sustained therapeutic levels of BiTE and suppresses tumor growth in a human ovarian cancer xenograft model. Collectively, the engineered alendronate calcium nanoneedle represents a bifunctional gene delivery platform for the efficient and synergistic treatment of ovarian cancer.

Diagnostic Value of Serum Angiogenesis Markers in Ovarian Cancer Using Multiplex Immunoassay

As cancer development involves pathological vessel formation, 16 angiogenesis markers were evaluated as potential ovarian cancer (OC) biomarkers. Blood samples collected from 172 patients were divided based on histopathological result: OC (n = 38), borderline ovarian tumours (n = 6), non-malignant ovarian tumours (n = 62), healthy controls (n = 50) and 16 patients were excluded. Sixteen angiogenesis markers were measured using BioPlex Pro Human Cancer Biomarker Panel 1 immunoassay. Additionally, concentrations of cancer antigen 125 (CA125) and human epididymis protein 4 (HE4) were measured in patients with adnexal masses using electrochemiluminescence immunoassay. In the comparison between OC vs. non-OC, osteopontin achieved the highest area under the curve (AUC) of 0.79 (sensitivity 69%, specificity 78%). Multimarker models based on four to six markers (basic fibroblast growth factor-FGF-basic, follistatin, hepatocyte growth factor-HGF, osteopontin, platelet-derived growth factor AB/BB-PDGF-AB/BB, leptin) demonstrated higher discriminatory ability (AUC 0.80-0.81) than a single marker (AUC 0.79). When comparing OC with benign ovarian tumours, six markers had statistically different expression (osteopontin, leptin, follistatin, PDGF-AB/BB, HGF, FGF-basic). Osteopontin was the best single angiogenesis marker (AUC 0.825, sensitivity 72%, specificity 82%). A three-marker panel consisting of osteopontin, CA125 and HE4 better discriminated the groups (AUC 0.958) than HE4 or CA125 alone (AUC 0.941 and 0.932, respectively). Osteopontin should be further investigated as a potential biomarker in OC screening and differential diagnosis of ovarian tumours. Adding osteopontin to a panel of already used biomarkers (CA125 and HE4) significantly improves differential diagnosis between malignant and benign ovarian tumours.

HER2-targeted antibody drug conjugates for ovarian cancer therapy

HER2 targeted delivery of ovarian cancer therapy has been beneficial for some patients, although, its efficacy is yet to be confirmed in large populations. We generated a novel anti-HER2 humanized antibody (Hertuzumab) and conjugated it to a microtubule-disrupting drug monomethyl auristatin E conjugate (MMAE) with a lysosomal protease-cleavable valine-citrulline linker. The average drug to antibody ratio (DAR) of Hertuzumab-vc-MMAE was varied by conjugating Hertuzumab antibodies with increasing linker-drugs (LDs) from D0-D8. The resulting conjugates were tested for kinetic affinity for soluble HER2-ECD, cytotoxicity, and in vivo pharmacokinetics. The kinetic binding constant values (KD) were obtained by the bio-layer interference (BLI) method. The half time (t1/2) and clearance (Cl) results of the pharmacokinetic profile in rats were DAR-dependent. Hertuzumab-vc-MMAE with DAR4 was selected for further evaluation. Both Hertuzumab and Hertuzumab conjugates could bind to HER2 antigen, and exhibited significant cytotoxicity on HER2 positive tumor cells after internalization by receptor-mediated endocytosis. Hence, Hertuzumab-vc-MMAE conjugates were significantly selective both in vitro and in vivo as compared to other ovarian cancer clinical therapies that are currently used. Cell signal transduction and cell cycle were also affected, as shown by down regulation of PI3K/AKT pathway and arrested mitosis in the G2/M phase. The pharmacokinetics and pharmacodynamics (PK-PD) of the conjugates in nude mouse xenograft model demonstrated a correlation between efficacy and drug concentration. These results show that Hertuzumab-vc-MMAE is a potential therapeutic agent for HER2 positive ovarian cancer.

Targeted immune therapy of ovarian cancer

Clinical outcomes, such as recurrence-free survival and overall survival, in ovarian cancer are quite variable, independent of common characteristics such as stage, response to therapy, and grade. This disparity in outcomes warrants further exploration and therapeutic targeting into the interaction between the tumor and host. One compelling host characteristic that contributes both to the initiation and progression of ovarian cancer is the immune system. Hundreds of studies have confirmed a prominent role for the immune system in modifying the clinical course of the disease. Recent studies also show that anti-tumor immunity is often negated by immune regulatory cells present in the tumor microenvironment. Regulatory immune cells also directly enhance the pathogenesis through the release of various cytokines and chemokines, which together form an integrated pathological network. Thus, in the future, research into immunotherapy targeting ovarian cancer will probably become increasingly focused on combination approaches that simultaneously augment immunity while preventing local immune suppression. In this article, we summarize important immunological targets that influence ovarian cancer outcome as well as include an update on newer immunotherapeutic strategies.

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

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

Dendritic cell immunotherapy in ovarian cancer

Ovarian cancer is one of the most frequent gynecological malignancies. However, as there is no effective screening method to detect early disease, it is usually only diagnosed when already widespread in the abdomen. The majority of patients diagnosed with advanced-stage disease will relapse and require additional therapy. In the search for additional effective treatments for the management of recurrent disease, researchers have focused on the potential usefulness of immunotherapeutic modulation by administering autologous immune cells, such as dendritic cells (DCs), to stimulate antitumor host responses. With the ultimate goal of improved survival, this review addresses mechanisms in ovarian cancer that may limit the expansion of antitumor immunity, discusses the parameters to be considered for optimal DC immunotherapy, outlines evaluation methodology used to monitor the success of treatment regimens and reviews reported DC immunotherapy trials in ovarian cancer.

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.

Epidermal growth factor receptor blockers for the treatment of ovarian cancer

BACKGROUND

Ovarian cancer is the seventh most common cause of cancer death in women world-wide. Treatment consists of a combination of surgical debulking and platinum-based chemotherapy, alone or in combination with paclitaxel. Between 55% and 75% of women who respond to first-line therapy relapse within two years of completing treatment. Second-line chemotherapy is palliative and aims to reduce symptoms and prolong survival. Increased understanding about the molecular basis of ovarian cancer has led to the development of novel agents, such as epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, and their effectiveness and toxicities in women with advanced ovarian cancer needs to be assessed.

OBJECTIVES

To compare the effectiveness and toxicities of epidermal growth factor receptor (EGFR) inhibitors alone or in combination with standard chemotherapy in the treatment of ovarian cancer.

SEARCH STRATEGY

We searched the Cochrane Gynaecological Cancer Group Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) Issue 4, 2010, MEDLINE and EMBASE up to October 2010. We also searched registers of clinical trials, abstracts of scientific meetings, and reference lists of included studies, and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing anti-EGFR agents with or without conventional chemotherapy versus conventional chemotherapy alone or no treatment in women with histologically proven ovarian cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data and assessed risk of bias. We reported adjusted hazard ratios (HRs) for overall and progression-free survival and risk ratios (RRs) comparing adverse events in women who received gemcitabine plus pertuzumab and gemcitabine plus placebo.

MAIN RESULTS

We found only one completed and three ongoing RCTs that met our inclusion criteria. The completed trial randomised 131 women with relapsed ovarian cancer to receive gemcitabine and pertuzumab or placebo and gemcitabine (control). There was no statistically significant difference in overall survival (OS), progression-free survival (PFS) and response between women who received gemcitabine and pertuzumab and those who received control, although PFS approached borderline significance (adjusted HR = 0.66, 95% CI 0.43 to 1.03; P = 0.06). The trial reported a higher rate of adverse events in the gemcitabine and pertuzumab arm for most outcomes, but most were not statistically significant (although many approached borderline significance) because the trial lacked statistical power due to its relatively small size and the low number of observed events. The trial was at moderate risk of bias.

AUTHORS' CONCLUSIONS

EGFR inhibitors, including pertuzumab, may add activity to conventional chemotherapy for treatment of platinum-resistant ovarian cancer. Certain subsets of women with particularly aggressive tumours resistant to conventional chemotherapy may benefit from EGFR inhibitor treatment. Further RCTs are necessary before EGFR inhibitors are introduced as first- or second-line treatment of ovarian cancer.

Immunity and immune suppression in human ovarian cancer

Clinical outcomes in ovarian cancer are heterogeneous, independent of common features such as stage, response to therapy and grade. This disparity in outcomes warrants further exploration into tumor and host characteristics. One compelling issue is the response of the patient's immune system to her ovarian cancer. Several studies have confirmed a prominent role for the immune system in modifying disease course. This has led to the identification and evaluation of novel immune-modulating therapeutic approaches such as vaccination and antibody therapy. Antitumor immunity, however, is often negated by immune suppression mechanisms present in the tumor microenvironment. Thus, in the future, research into immunotherapy targeting ovarian cancer will probably become increasingly focused on combination approaches that simultaneously augment immunity while preventing local immune suppression. In this article, we summarize important immunological issues that could influence ovarian cancer outcome, including tumor antigens, endogenous immune responses, immune escape and new and developing immunotherapeutic strategies.

Polyclonal antitumor immunoglobulin may play a role in ovarian cancer adjuvant therapy

Currently, surgery plus adjuvant chemotherapy are the mainstay of care in the treatment of ovarian cancer. Although this therapeutic strategy has been considered as "golden standard" regimen with profound impact on survival improvement, several obstacles have been encountered, such as chemotherapy drug resistance and disease relapse. Residual cancer cells in the abdominal cavity and vessels are considered as the main cause of disease relapse. New treatment options attempt to yield higher survival rate in patients. Monoclonal antibodies such as Trastuzumab and Cetuximab showed promising effects on several solid tumors. But for epithelial ovarian cancer, modalities of intravenous monoclonal antibody monotherapy have not achieved expected results as they have in the treatments of breast and colorectal cancer. Relatively low expression of matched receptors on ovarian cancer cells, as well as the intravenous delivery with less efficacy of intra-abdominal antibody accumulation, may account for lack of efficacy of monoclonal antibody on ovarian cancer. So we hypothesize that polyvalent antibodies boosted from rabbit by inoculating human tumor cells could deplete ovarian cancer cells through intraperitoneal route. The mechanisms may include interrupting ligand-receptor binding and thus result in blockage of intracellular signaling pathways such as EGFR and HER2 signal transduction, and possibly may also involve antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity.

A molecularly targeted theranostic probe for ovarian cancer

Overexpression of the human epidermal growth factor receptor (HER) family has been implicated in ovarian cancer because of its participation in signaling pathway regulating cellular proliferation, differentiation, motility, and survival. Currently, effective diagnostic and therapeutic schemes are lacking for treating ovarian cancer, and consequently ovarian cancer has a high mortality rate. Although HER2 receptor expression does not usually affect the survival rates of ovarian cancer to the same extent as in breast cancer, it can be used as a docking site for directed nanotherapies in cases with de novo or acquired chemotherapy resistance. In this study, we have exploited a novel gold nanoshell-based complex (nanocomplex) for targeting, dual modal imaging, and photothermal therapy of HER2-overexpressing and drug-resistant ovarian cancer OVCAR3 cells in vitro. The nanocomplexes are engineered to simultaneously provide contrast as fluorescence optical imaging probe and a magnetic resonance imaging agent. Immunofluorescence staining and magnetic resonance imaging successfully show that nanocomplex-anti-HER2 conjugates specifically bind to OVCAR3 cells as opposed to the control, MDA-MB-231 cells, which have low HER2 expression. In addition, nanocomplexes targeted to OVCAR3 cells, when irradiated with near-IR laser, result in selective destruction of cancer cells through photothermal ablation. We also show that near-IR light therapy and the nanocomplexes by themselves are noncytotoxic in vitro. To the best of our knowledge, this is the first successful integration of dual modal bioimaging with photothermal cancer therapy for treatment of ovarian cancer. Based on their efficacy in vitro, these nanocomplexes are highly promising for image-guided photothermal therapy of ovarian cancer, as well as other HER2-overexpressing cancers. Mol Cancer Ther; 9(4); 1028-38. (c)2010 AACR.