MicroRNA-135a-3p as a promising biomarker and nucleic acid therapeutic agent for ovarian cancer.

Ovarian cancer is the most lethal gynecologic malignancy. Recently, several molecularly targeted anticancer agents have been developed for ovarian cancer; however, its prognosis remains extremely poor. The development of molecularly targeted therapy, as well as companion diagnostics, is required to improve outcomes for patients with ovarian cancer. In this study, to identify microRNAs (miRNAs) involved in the progression of ovarian cancer we analyzed serum miRNAs in patients with ovarian cancer using miRNA array and quantitative RT-PCR and examined the anticancer properties of miRNA expression in ovarian cancer cells. In patients with ovarian cancer, high amount of miR-135a-3p in serum samples was significantly associated with favorable clinical prognosis. The amount of miR-135a-3p was significantly decreased in patients with ovarian cancer compared with patients with ovarian cysts or normal ovaries. In SKOV-3 and ES-2 human ovarian cancer cells, enhanced expression of miR-135a-3p induced drug sensitivity to cisplatin and paclitaxel and suppressed cell proliferation and xenograft tumor growth. These findings suggest that miR-135a-3p may be considered as a biomarker and a therapeutic agent in ovarian cancer.

BK-UM in patients with recurrent ovarian cancer or peritoneal cancer: a first-in-human phase-I study.

BACKGROUND: BK-UM (CRM197) is a mutant form of diphtheria toxin and a specific inhibitor of heparin-binding epidermal growth factor-like growth factor (HB-EGF). We assessed the safety, pharmacokinetics, recommended dose, and efficacy of BK-UM in patients with recurrent ovarian cancer (OC) or peritoneal cancer (PC), and measured HB-EGF levels in serum and abdominal fluid after BK-UM administration. METHODS: Eleven patients with advanced or recurrent OC or PC were enrolled and treated with BK-UM via the intraperitoneal route. The dose was escalated (1.0, 2.0, 3.3, and 5.0 mg/m2) using a 3 + 3 design. RESULTS: Eight of 11 patients completed treatment. No dose-limiting toxicity (DLT) was experienced at dose levels 1 (1.0 mg/m2) and 2 (2.0 mg/m2). Grade 3 transient hypotension as an adverse event (defined as a DLT in the present study) was observed in two of four patients at dose level 3 (3.3 mg/m2). Treatment with BK-UM was associated with decreases in HB-EGF levels in serum and abdominal fluid in seven of 11 patients and five of eight patients, respectively. Clinical outcomes included a partial response in one patient, stable disease in five patients, and progressive disease in five patients. CONCLUSIONS: BK-UM was well tolerated at doses of 1.0 and 2.0 mg/m2, with evidence for clinical efficacy in patients with recurrent OC or PC. A dose of 2.0 mg/m2 BK-UM is recommended for subsequent clinical trials. TRIAL REGISTRATION: This trial was prospectively performed as an investigator-initiated clinical trial. The trial numbers are UMIN000001002 and UMIN000001001, with registration dates of 1/30/2008 and 2/4/2008, respectively. UMIN000001001 was registered as a trial for the continuous administration of BK-UM after UMIN000001002 .

Clinical Features of Recurrence in Patients Without Residual Tumour in Endometrial Cancer.

BACKGROUND/AIM: Initial treatment of endometrial cancer with surgery and platinum and taxane-based chemotherapy is often successful, but it remains unclear as to whether certain types of the disease relapse. The aim of this study was to identify the clinical features of recurrence in patients without residual tumour in endometrial cancer. PATIENTS AND METHODS: Clinical features, histological type, and time to recurrence were analyzed in 640 endometrial cancer patients without residual tumours. RESULTS: Of 640 patients, 517 were type I and 123 were type II. For type I, early recurrent (ER) disease and late recurrent (LR) disease were noted in 80 and 8 patients, respectively, and 97.5% of ER occurred within 2 years. After recurrence, 76.2% of ER and 50% of LR patients died. In type II, ER and LR were noted in 41 and 1 patients, respectively, and 97.6% of ER occurred within 2 years, of which 75.6% died after recurrence. One LR case died of disease. CONCLUSION: Most patients recurred within 2 years irrespective of clinical stage or type.

HB-EGF Is a Promising Therapeutic Target for Lung Cancer with Secondary Mutation of EGFRT790M.

Advanced lung cancer is one of the most lethal malignancies. Many anticancer agents have been developed for lung cancer with epidermal growth factor receptor (EGFR) mutations, but its prognosis remains extremely poor. The development of molecularly-targeted therapies is required for patients with lung cancer with secondary mutation of the EGFR gene. In this study, in order to assess the validity of heparin-binding EGF-like growth factor (HB-EGF) as a therapeutic target for lung cancer with EGFR mutation, we examined the antitumor effects of a specific inhibitor (cross-reacting material 197; CRM197) on lung cancer cells with EGFR mutation. HB-EGF was the most predominantly expressed EGFR ligand in lung cancer cells with EGFR mutation. CRM197 induced significant cell apoptosis and marked suppression of tumorigenicity in lung cancer cells with single or double mutation of EGFR. These results suggest that HB-EGF is a rational target for the treatment of lung cancer with EGFR mutation.

Anti-tumor Effect of Intravenous Administration of CRM197 for Triple-negative Breast Cancer Therapy.

BACKGROUND/AIM: Heparin-binding epidermal growth factor-like growth factor (HB-EGF), which belongs to the epidermal growth factor family, is a rational therapeutic target for triple-negative breast cancer (TNBC). This study aimed to assess the anti-tumor efficacy of intravenous (i.v.) HB-EGF-specific inhibitor (CRM197) for TNBC. MATERIALS AND METHODS: NOD/SCID mice were subcutaneously injected withTNBC cells, MDA-MB-231, and, then, treated with i.v. CRM197 in either dose- or frequency-dependent manners, using an advanced cancer model and an adjuvant therapy model. Tumor volume and mouse body weight were calculated weekly. Statistical significance was assessed by the Mann-Whitney U-test. RESULTS: Mice that received i.v. CRM197 showed a significant anti-tumor effect in dose- and frequency-dependent manners in both models. However, their body weight did not differ significantly among groups. CONCLUSION: These results suggest that i.v. CRM197 is an effective treatment for TNBC.

Validity of HB-EGF as Target for Human Neuroblastoma Therapy.

BACKGROUND/AIM: Neuroblastoma (NB) is the most common and lethal extracranial solid tumor in children. The present study aimed to verify that the heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a rational target in NB therapy. MATERIAL AND METHODS: We examined expression of EGFR ligands in four NB cell lines using 2-dimensional culture (DC) and 3DC conditions. To assess the anti-tumor effect of cross-reacting material 197 (CRM197), which is a specific inhibitor of HB-EGF, on NB cells, we also performed terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay to detect apoptotic cells. RESULTS: HB-EGF was predominantly expressed in two out of four NB cell lines under 2DC and 3DC conditions. CRM197 significantly induced apoptosis of NB cells with high HB-EGF expression. CONCLUSION: HB-EGF plays an important role in neuroblastoma tumorigenesis and CRM197 showed an effective antitumor effect in neuroblastoma cells.

Warburg effect regulated by amphiregulin in the development of colorectal cancer.

Colorectal cancer (CRC) is one of the most frequently occurring cancers with high morbidity and mortality worldwide. Amphiregulin (AREG), a member of the epidermal growth factor family and a rational target for CRC therapy, is essential for the three-dimensional structure of tumor formation. To clone the genes associated with increased AREG expression, we performed a cDNA microarray analysis in two CRC cell lines undergoing two-dimensional (2DC) and three-dimensional culture (3DC). Upregulated (>2.0-fold) and downregulated (<0.5-fold) genes in 3DC compared with 2DC were selected. Pathway analysis using DAVID based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway databases revealed a number of genes involved in glycolysis. In CRC cells, glucose elevated the expression of GLUT1 and AREG as well as the activity of the hypoxia-inducible factor 1 (HIF-1) luciferase reporter promoter. The suppression of AREG expression reduced the uptake of glucose and production of lactate. Luciferase assay identified a critical regulatory region for AREG expression between -130 and -180 bp upstream of the start site, which contained a carbohydrate response element (ChoRE). Max-like protein X (MLX) bound to ChoRE and enhanced the expression of AREG. Together these data suggest that AREG plays a pivotal role in the development of CRC through activation of the Warburg effect.

Clinical Efficacy of Aprepitant in Patients with Gynecological Cancer after Chemotherapy Using Paclitaxel and Carboplatin.

AIM: This study aimed to evaluate the efficacy of aprepitant, a neurokinin (NK)1 receptor antagonist, on chemotherapy-induced nausea and vomiting (CINV). PATIENTS AND METHODS: A randomized, open-labeled, parallel-design study was undertaken in gynecologic-cancer (GC) patients at the Fukuoka University Hospital. Twenty-three patients were divided into without (group A) or with aprepitant (Group B) in the first cycle of paclitaxel and carboplatin (TC) therapy. From the second cycle onwards, all patients used aprepitant. Statistical significance was assessed using McNemar and Chi-square tests. RESULTS: In the first cycle, the prevalence of a complete response, no episodes of nausea or food intake in group B was significantly increased compared to group A. No significant difference in the prevalence of a complete response or food intake situation was found from the second cycle onwards. CONCLUSION: Combination of aprepitant with standard anti-emetic therapy may contribute to prevention of CINV in TC therapy for GC patients.

The Safety of Pegylated Liposomal Doxorubicin Plus Irinotecan in Recurrent Ovarian Cancer Patients: A Phase I Trial.

AIM: The study was designed to evaluate the safety of combined chemotherapy with pegylated liposomal doxorubicin (PLD) and irinotecan (CPT-11) in patients with recurrent ovarian cancer. PATIENTS AND METHODS: Six patients with platinum-resistant and taxane-pretreated ovarian cancer were enrolled in the study based on the traditional 3-plus-3 design. PLD was administered intravenously on day 1 and CPT-11 on days 1 and 8 of each 28-day course. Initial doses were 30 mg/m(2) PLD and 50 mg/m(2) CPT-11. RESULTS: Hematotoxicity was the principal toxicity (1 patient developed grade 3 neutropenia and 2 developed grade 3 leukocytopenia); hand-foot syndrome was not observed. Furthermore, 1 patient achieved complete response, whereas 2 patients achieved partial response. CONCLUSION: The combined PLD and CPT-11 regimen was well-tolerated indicating its potential clinical benefit for ovarian cancer patients.

Proteolysis of EphA2 Converts It from a Tumor Suppressor to an Oncoprotein.

Eph receptor tyrosine kinases are considered candidate therapeutic targets in cancer, but they can exert opposing effects on cell growth. In the presence of its ligands, Eph receptor EphA2 suppresses signaling by other growth factor receptors, including ErbB, whereas ligand-independent activation of EphA2 augments ErbB signaling. To deploy EphA2-targeting drugs effectively in tumors, the anti-oncogenic ligand-dependent activation state of EphA2 must be discriminated from its oncogenic ligand-independent state. Because the molecular basis for the latter is little understood, we investigated how the activation state of EphA2 can be switched in tumor tissue. We found that ligand-binding domain of EphA2 is cleaved frequently by the membrane metalloproteinase MT1-MMP, a powerful modulator of the pericellular environment in tumor cells. EphA2 immunostaining revealed a significant loss of the N-terminal portion of EphA2 in areas of tumor tissue that expressed MT1-MMP. Moreover, EphA2 phosphorylation patterns that signify ligand-independent activation were observed specifically in these areas of tumor tissue. Mechanistic experiments revealed that processing of EphA2 by MT1-MMP promoted ErbB signaling, anchorage-independent growth, and cell migration. Conversely, expression of a proteolysis-resistant mutant of EphA2 prevented tumorigenesis and metastasis of human tumor xenografts in mice. Overall, our results showed how the proteolytic state of EphA2 in tumors determines its effector function and influences its status as a candidate biomarker for targeted therapy.

Contribution of transcription factor, SP1, to the promotion of HB-EGF expression in defense mechanism against the treatment of irinotecan in ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) is a worst histological subtype than other ovarian malignant tumor. Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a promising target for ovarian cancer therapy. The aims of this study were to validate the efficacy of HB-EGF-targeted therapy for OCCC and to identify the transcription factor that contributed to the induction of HB-EGF by SN38 treatment in OCCC cells. HB-EGF was highly expressed in OCCC cells, and an increase of HB-EGF was induced by SN38 which had only antitumor effect among conventional anticancer agents on OCCC. A specific inhibitor of HB-EGF, a cross-reacting material 197 (CRM197), led to a synergistic increase in the number of apoptotic OCCC cells with the treatment of SN38. The luciferase assay with 5'-deletion promoter constructs identified a GC-rich element between -125 and -178 (the distal transcription start site was denoted +1) as a cis-regulatory region, and the treatment of SN38 induced luciferase activity in this region. An in silico and chromatin immunoprecipitation analysis estimated that SP1 bound to the cis-regulatory region of HB-EGF in OCCC cells. Real-time PCR and cell viability assays showed that the transfection of a small interfering RNA targeting SP1 suppressed the expression of HB-EGF induced by SN38, resulting in the enhanced sensitivity of SN38. Taken together, these results indicate that induction of HB-EGF expression contributed to defense mechanism against treatment of SN38 through the transcriptional activity of SP1 in OCCC cells.

Pre-clinical study of BK-UM, a novel inhibitor of HB-EGF, for ovarian cancer therapy.

BACKGROUND/AIM: Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a member of the epidermal growth factor family, is a target for ovarian cancer therapy. The present study investigated the administration schedule of BK-UM, an anticancer agent targeting HB-EGF. MATERIALS AND METHODS: The ovarian cancer cell line, RMG-I, was injected subcutaneously into five-week-old female nude mice. The BK-UM was administered intraperitoneally, using three administration schedules with different doses. The tumor volume was calculated every week. Statistical significance was assessed using the Mann-Whitney U-test. RESULTS: At doses >0.1 mg/kg, BK-UM displayed significant antitumor effects, although the antitumor effects and body weights of mice did not significantly differ by dose or by three different administration schedules. At a dose <0.1 mg/kg, however, BK-UM had little inhibitory effect on tumor growth. CONCLUSION: Daily administration of BK-UM, which has a potentially dose-dependent antitumor effect, may be the optimal schedule for clinical application.

Tumor-targeted photodynamic therapy.

Photodynamic therapy (PDT) is a well-established clinical treatment modality for various diseases, including cancer. It involves the topical or systemic administration of a photosensitizer, followed by selective irradiation of the target lesion with a specific wavelength of non-ionizing light, which triggers oxidative photodamage and subsequent death of the targeted cells. Due to this two-step therapeutic process, PDT is a safe and minimally-invasive therapy. Nevertheless, classical non-targeted photosensitizers lack sufficient tumor selectivity and are taken up in the neighboring normal tissues, resulting in undesirable adverse effects. To overcome this obstacle, diverse tumor-targeting approaches have been developed. In this article, we discuss the current strategies and rationale regarding tumor-targeted PDT.

Possible therapeutic targets among the molecules involved in the Warburg effect in tumor cells.

The majority of human tumors display a high rate of glycolysis under aerobic conditions. This phenomenon was recognized approximately seven decades ago and is known as the Warburg effect. Several key enzymes required to maintain this high level of glucose metabolism are found in tumor cells. The effects of the glycolytic enzymes are known to be directly or indirectly regulated by various signaling pathways, oncogenes, suppressor genes and transcription factors. Recent molecular biology studies have shown that multiple genetic alterations are related to tumor development. Therefore, these factors may be rational targets for cancer therapy. In this short review, we describe several important molecules that affect aerobic glycolysis and discuss their possible use as therapeutic targets for cancer.

Molecular hierarchy of heparin-binding EGF-like growth factor-regulated angiogenesis in triple-negative breast cancer.

Heparin-binding EGF-like growth factor (HB-EGF) is one of several proangiogenic factors and represents a possible therapeutic target for patients with triple-negative breast cancer (TNBC). However, the role of HB-EGF in promoting tumor aggressiveness in TNBC remains unclear. To investigate specific genes and pathways involved in TNBC tumorigenesis, we profiled gene expression changes in two TNBC cell lines under two-dimensional culture (2DC) and three-dimensional culture (3DC) and in a tumor xenograft model. We identified simultaneous upregulation of HB-EGF, VEGFA, and angiopoietin-like 4 (ANGPTL4) in 3DC and tumor xenografts, compared with 2DC. We show that HB-EGF regulates the expression of VEGFA or ANGPTL4 via transcriptional regulation of hypoxia-inducible factor-1α and NF-κB. Furthermore, suppression of VEGFA or ANGPTL4 expression enhanced HB-EGF expression, highlighting a unique regulatory loop underlying this angiogenesis network. Targeted knockdown of HB-EGF significantly suppressed tumor formation in a TNBC xenograft model, compared with individual knockdown of either VEGFA or ANGPTL4, by reducing the expression of both VEGFA and ANGPTL4. In patients with TNBC, VEGFA or ANGPTL4 expression was also significantly correlated with HB-EGF expression. Low concentrations of exogenously added HB-EGF strongly activated the proliferation of endothelial cells, tube formation, and vascular permeability in blood vessels, in a similar fashion to high doses of VEGFA and ANGPTL4. Taken together, these results suggest that HB-EGF plays a pivotal role in the acquisition of tumor aggressiveness in TNBC by orchestrating a molecular hierarchy regulating tumor angiogenesis.

Regulatory mechanisms of the HB-EGF autocrine loop in inflammation, homeostasis, development and cancer.

Heparin binding epidermal growth factor-like growth factor (HB-EGF) is involved in development and homeostasis as well as in pathological processing of chronic diseases, especially cancer. Enhancement of HB-EGF expression is directly or indirectly regulated by transcriptional factors, including activator protein-1 (AP-1), specificity protein (SP)1, SP3, nuclear factor kappa B (NF-κB), hypoxia inducible factor 1, alpha subunit (HIF-1α, myogenic differentiation 1 (MyoD), Wilms tumor 1 (WT-1) and snail homolog 1 (Snail), and also by microRNAs. These transcription or post-transcription factors may communicate to form an autocrine HB-EGF amplification loop. Emerging evidence has indicated that HB-EGF is a rational target for the therapy of cancer and atherosclerosis. In this review, we discuss the relationship between the HB-EGF autocrine loop and HB-EGF transcriptional factors, and we highlight HB-EGF as a therapeutic target in diverse diseases.

Assessment of HB-EGF levels in peritoneal fluid and serum of ovarian cancer patients using ELISA.

BACKGROUND: Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a rational target for ovarian cancer therapy. The aim of this study was to examine HB-EGF levels in the peritoneal fluid and serum of ovarian cancer (OVCA) patients. PATIENTS AND METHODS: Samples were collected from six healthy women, 21 OVCA patients, and 21 ovarian cyst patients. HB-EGF levels were measured using a sandwich ELISA kit and calculated using a parallel line assay. RESULTS: No significant difference between the slopes of the standard and sample curves was observed at an anti-HB-EGF antibody concentration of 1.6 µg/ml. HB-EGF levels in the peritoneal fluid and serum of OVCA patients were significantly higher than those in patients with ovarian cysts or controls. Serum HB-EGF levels were also significantly correlated with levels in peritoneal fluid in OVCA patients. CONCLUSION: We developed an assay for the exact measurement of HB-EGF levels in peritoneal fluid and serum.