Gloria S. Huang

Potentiation of taxol efficacy and by discodermolide in ovarian carcinoma xenograft-bearing mice

Purpose: To evaluate the drug combination of discodermolide and Taxol in human ovarian cancer cells and in an in vivo model of ovarian carcinoma. Experimental Design: The combination index method was used to evaluate the interaction of Taxol and discodermolide in human ovarian SKOV-3 carcinoma cells. Data were correlated with alterations in cell cycle distribution and caspase activation. In addition, SKOV-3 xenograft-bearing mice were treated with either Taxol, discodermolide, or a combination of both drugs given concurrently to evaluate the antitumor efficacy and toxicity of this combination. The Matrigel plug assay and CD31 immunohistochemistry were done to assess antiangiogenic effects. Results: Taxol and discodermolide interact synergistically over a range of concentrations and molar ratios that cause drug-induced aneuploidy in ovarian carcinoma cells. In SKOV-3 xenograft-bearing mice, the combination is significantly superior to either single agent, and induces tumor regressions without notable toxicities. Immunohistochemical analysis of CD31 and Matrigel plug analysis show decreased vessel formation in mice treated with the combination relative to either drug alone. Conclusions: The synergistic activity of Taxol and discodermolide in cells is most potent at drug concentrations that result in drug-induced aneuploidy rather than mitotic arrest. Moreover, in an animal model of ovarian carcinoma, this is a well-tolerated combination that induces tumor regressions and suppresses angiogenesis. These data confirm the potency of this combination and support the use of concurrent low doses of Taxol and discodermolide for potential use in cancer therapeutics.

Insulin-like Growth Factor 2 Expression Modulates Taxol Resistance and Is a Candidate Biomarker for Reduced Disease-Free Survival in Ovarian Cancer

Purpose: This study was undertaken to examine the role of the insulin-like growth factor (IGF) signaling pathway in the response of ovarian cancer cells to Taxol and to evaluate the significance of this pathway in human epithelial ovarian tumors. Experimental Design: The effect of Taxol treatment on AKT activation in A2780 ovarian carcinoma cells was evaluated using antibodies specific for phospho-AKT. To study the drug-resistant phenotype, we developed a Taxol-resistant cell line, HEY-T30, derived from HEY ovarian carcinoma cells. IGF2 expression was measured by real-time PCR. A type 1 IGF receptor (IGF1R) inhibitor, NVP-AEW541, and IGF2 small interfering RNA were used to evaluate the effect of IGF pathway inhibition on proliferation and Taxol sensitivity. IGF2 protein expression was evaluated by immunohistochemistry in 115 epithelial ovarian tumors and analyzed in relation to clinical/pathologic factors using the χ2 or Fishers exact tests. The influence of IGF2 expression on survival was studied with Cox regression. Results: Taxol-induced AKT phosphorylation required IGF1R tyrosine kinase activity and was associated with upregulation of IGF2. Resistant cells had higher IGF2 expression compared with sensitive cells, and IGF pathway inhibition restored sensitivity to Taxol. High IGF2 tumor expression correlated with advanced stage (P < 0.001) and tumor grade (P < 0.01) and reduced disease-free survival (P < 0.05). Conclusions: IGF2 modulates Taxol resistance, and tumor IGF2 expression is a candidate prognostic biomarker in epithelial ovarian tumors. IGF pathway inhibition sensitizes drug-resistant ovarian carcinoma cells to Taxol. Such novel findings suggest that IGF2 represents a therapeutic target in ovarian cancer, particularly in the setting of Taxol resistance. Clin Cancer Res; 16(11); 2999–3010. ©2010 AACR.

Abstract 5020: Potential lifestyle intervention in inner city women with endometrial cancer: A pilot study

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Hypothesis: Evidence suggests that modification of diet and exercise practices may prevent cancer recurrence. It may also decrease the risk factors for the leading causes of death in women including heart disease and stroke. Methods: 100 patients with previously diagnosed endometrial cancer were enrolled in a pilot study to collect data regarding current lifestyle, willingness to change and preferred programs of nutrition and exercise. All enrolled subjects were verbally asked to respond to a questionnaire that included validated and novel instruments. Results: Mean age was 64 (39-86 years) and mean body mass index was 34 kg/m2 (17-55). 38% of the responders were Black/African American, 33% were Caucasian, and 21% were Hispanic. Of these, 69% were born in the United States of America. 75% described themselves as “overweight”. The most common mode of current exercise was walking (54%). 89% of the patients responded that they would be interested in participating in a diet or exercise program. The most common reason that women stated they would want to participate was to improve overall health (48%). Only 4% stated that they thought it would prevent recurrence of their cancers. Diabetes mellitus was previously diagnosed in 30% of participants. Eighty three percent of diabetic patients had body mass index over 30 kg/m2 and 30% had body mass index over 40 kg/m2. Eleven patients currently on therapy for diabetes had hemoglobin A1C values greater then 6.5 and are at risk for microvessel damage and end-organ dysfunction including kidney failure and impaired vision Discussion: These data present the opinions of a racially heterogeneous group of women at risk for cancer recurrence, as well as the morbidity and mortality related to obesity and diabetes. These data suggest that women at our center should participate in a dietary and exercise intervention program and our patients would benefit from the additional health education. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5020. doi:10.1158/1538-7445.AM2011-5020

Co-expression of GPR30 and ERβ and their association with disease progression in uterine carcinosarcoma

OBJECTIVE We sought to evaluate the expression of G protein-coupled receptor 30 (GPR30) and estrogen receptor (ER)beta in uterine carcinosarcoma (CS). STUDY DESIGN Immunohistochemistry was performed using antibodies to GPR30, ERbeta, ERalpha, and progesterone receptor (PR). The staining intensity and percentage of positive cells were scored for each tissue section. Expression levels were compared using the Wilcoxon rank sum test. Correlation was evaluated by Spearman rho and logistic regression. RESULTS Compared with normal endometrium, CS had lower ERalpha and PR expression (both P < .01) but higher GPR30 epithelial expression (P = .03). Advanced-stage CS had higher GPR30 (P < .01) and ERbeta (P = .02) epithelial expression compared with early-stage CS. Expression of GPR30 and ERbeta correlated with each other (P < .01), and not with ERalpha or PR. CONCLUSION In uterine CS, GPR30 and ERbeta are coordinately overexpressed and expression levels increase in advanced-stage disease, supporting the involvement of alternative ERs in disease progression.

IGF2 signaling and regulation in cancer

Upregulation of IGF2 occurs in both childhood and adult malignancies. Its overexpression is associated with resistance to chemotherapy and worse prognosis. IGF2 promoter usage is developmentally regulated; however, malignant tissues are characterized by re-activation of the fetal IGF2 promoters, especially P3. In this review, we describe the mechanisms of IGF2 signaling and regulation in normal and malignant tissues and their clinical implications.

Insulin-Like Growth Factor 2 Silencing Restores Taxol Sensitivity in Drug Resistant Ovarian Cancer

Drug resistance is an obstacle to the effective treatment of ovarian cancer. We and others have shown that the insulin-like growth factor (IGF) signaling pathway is a novel potential target to overcome drug resistance. The purpose of this study was to validate IGF2 as a potential therapeutic target in drug resistant ovarian cancer and to determine the efficacy of targeting IGF2 in vivo. An analysis of The Cancer Genome Atlas (TCGA) data in the serous ovarian cancer cohort showed that high IGF2 mRNA expression is significantly associated with shortened interval to disease progression and death, clinical indicators of drug resistance. In a genetically diverse panel of ovarian cancer cell lines, the IGF2 mRNA levels measured in cell lines resistant to various microtubule-stabilizing agents including Taxol were found to be significantly elevated compared to the drug sensitive cell lines. The effect of IGF2 knockdown on Taxol resistance was investigated in vitro and in vivo. Transient IGF2 knockdown significantly sensitized drug resistant cells to Taxol treatment. A Taxol-resistant ovarian cancer xenograft model, developed from HEY-T30 cells, exhibited extreme drug resistance, wherein the maximal tolerated dose of Taxol did not delay tumor growth in mice. Blocking the IGF1R (a transmembrane receptor that transmits signals from IGF1 and IGF2) using a monoclonal antibody did not alter the response to Taxol. However, stable IGF2 knockdown using short-hairpin RNA in HEY-T30 effectively restored Taxol sensitivity. These findings validate IGF2 as a potential therapeutic target in drug resistant ovarian cancer and show that directly targeting IGF2 may be a preferable strategy compared with targeting IGF1R alone.

Downregulation of Filamin A Interacting Protein 1-Like is Associated with Promoter Methylation and Induces an Invasive Phenotype in Ovarian Cancer

Ovarian cancer is the most lethal gynecologic malignancy with a five-year survival rate below 25% for patients with stages III and IV disease. Identifying key mediators of ovarian cancer invasion and metastasis is critical to the development of more effective therapeutic interventions. We previously identified Filamin A interacting protein 1-like (FILIP1L) as an important mediator of cell proliferation and migration. In addition, targeted expression of FILIP1L in tumors inhibited tumor growth in vivo. In our present study, we confirmed that both mRNA and protein expression of FILIP1L were downregulated in ovarian cancer cells compared with normal ovarian epithelial cells. FILIP1L expression was inversely correlated with the invasive potential of ovarian cancer cell lines and clinical ovarian cancer specimens. We also provide evidence that DNA methylation is a mechanism by which FILIP1L is downregulated in ovarian cancer. The CpG island in the FILIP1L promoter was heavily methylated in ovarian cancer cells. Methylation status of the FILIP1L promoter was inversely correlated with FILIP1L expression in ovarian cell lines and clinical ovarian specimens. Reduced methylation in the FILIP1L promoter following treatment with a DNA demethylating agent was associated with restoration of FILIP1L expression in ovarian cancer cells. A transcription activator, cAMP-responsive element binding protein (CREB) was shown to bind to the CREB/ATF site in the CpG island of the FILIP1L promoter. Overall, these findings suggest that downregulation of FILIP1L associated with DNA methylation is related with the invasive phenotype in ovarian cancer and that modulation of FILIP1L expression has the potential to be a target for ovarian cancer therapy. Mol Cancer Res; 9(8); 1126–38. ©2011 AACR.

Evasion of anti-growth signaling: A key step in tumorigenesis and potential target for treatment and prophylaxis by natural compounds.

The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and Krüppel-like factor 5 (KLF5) pathways. Aberrations in these processes in cancer cells involve mutations and thus the suppression of genes that prevent growth, as well as mutation and activation of genes involved in driving cell growth. Using these pathways as examples, we prioritize molecular targets that might be leveraged to promote anti-growth signaling in cancer cells. Interestingly, naturally occurring phytochemicals found in human diets (either singly or as mixtures) may promote anti-growth signaling, and do so without the potentially adverse effects associated with synthetic chemicals. We review examples of naturally occurring phytochemicals that may be applied to prevent cancer by antagonizing growth signaling, and propose one phytochemical for each pathway. These are: epigallocatechin-3-gallate (EGCG) for the Rb pathway, luteolin for p53, curcumin for PTEN, porphyrins for Hippo, genistein for GDF15, resveratrol for ARID1A, withaferin A for Notch and diguelin for the IGF1-receptor pathway. The coordination of anti-growth signaling and natural compound studies will provide insight into the future application of these compounds in the clinical setting.

Extragenital adenosarcoma: A case report, review of the literature, and management discussion

BACKGROUND Müllerian adenosarcoma is a rare mixed epithelial-mesenchymal tumor. An extragenital site of origin and sarcomatous overgrowth are associated with aggressive clinical behavior. CASE We present a rare case of extragenital adenosarcoma with sarcomatous overgrowth and coexistent endometriosis. She was treated with initial cytoreductive surgery and chemotherapy. She underwent a second surgery for management of a high-grade bowel obstruction, due to pathologically confirmed recurrent intraperitoneal adenosarcoma. A complete clinical response was achieved with liposomal doxorubicin, and the patient remains disease-free eighteen months after completion of chemotherapy. CONCLUSION Liposomal doxorubicin appears to be an active agent for the treatment of adenosarcoma with sarcomatous overgrowth. In addition, we conclude from our review of all reported cases of extragenital adenosarcoma that concurrent endometriosis may represent a favorable prognostic factor.

A phase II study of weekly topotecan and docetaxel in heavily treated patients with recurrent uterine and ovarian cancers

OBJECTIVES A phase II trial designed to evaluate the safety and efficacy of weekly topotecan and docetaxel in heavily treated patients with recurrent uterine or epithelial ovarian cancers. METHODS Eligible patients with recurrent epithelial ovarian or uterine cancers were treated with weekly topotecan 3.5 mg/m(2) and docetaxel 30 mg/m(2) for 3 consecutive weeks. Cycles were repeated every 4 weeks for 6 cycles or until evidence of disease progression, unacceptable toxicity, or death. Response was assessed as per RECIST or Rustins criteria. Time to best response and overall survival were calculated using Kaplan-Meier statistical methods. RESULTS Twenty-seven patients registered, of which 24 were evaluable for response. The majority of patients had received 2 prior chemotherapy regimens. Of the total 86 cycles of chemotherapy that were administered, there were three grade 4 (all neutropenia) and ten grade 3 toxicities. Six of the grade 3 non-hematologic toxicities were unrelated to treatment. There were 8 dose delays and 4 dose reductions. The overall response rate was 25% (95% CI: 7.7%-42.3%, 8% CR, 17% PR), and 38% of the patients had clinical benefit (95% CI: 18.1%-56.9%; CR+PR+13% SD). The median duration of response was 8.5 months (range 3-19 months). The median overall survival was 18.5 months (range 1.8-50.7 months). CONCLUSION The combination of weekly topotecan and docetaxel has clinical benefit and is well tolerated in this heavily treated patient population. Patients with platinum-resistant tumors had clinical benefit and should be considered for further study with this regimen.