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Choy, Edwin

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Choy

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Edwin

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Choy, Edwin
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Now showing 1 - 10 of 15
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    Targeting DYRK1B suppresses the proliferation and migration of liposarcoma cells
    (Impact Journals LLC, 2018) Chen, Hua; Shen, Jacson; Choy, Edwin; Hornicek, Francis J.; Shan, Aijun; Duan, Zhenfeng
    Liposarcoma is a common subtype of soft tissue sarcoma and accounts for 20% of all sarcomas. Conventional chemotherapeutic agents have limited efficacy in liposarcoma patients. Expression and activation of serine/threonine-protein kinase dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1B (DYRK1B) is associated with growth and survival of many types of cancer cells. However, the role of DYRK1B in liposarcoma remains unknown. In this study, we investigated the functional and therapeutic relevance of DYRK1B in liposarcoma. Tissue microarray and immunohistochemistry analysis showed that higher expression levels of DYRK1B correlated with a worse prognosis. RNA interference-mediated knockdown of DYRK1B or targeting DYRK1B with the kinase inhibitor AZ191 inhibited liposarcoma cell growth, decreased cell motility, and induced apoptosis. Moreover, combined AZ191 with doxorubicin demonstrated an increased anti-cancer effect on liposarcoma cells. These findings suggest that DYRK1B is critical for the growth of liposarcoma cells. Targeting DYRK1B provides a new rationale for treatment of liposarcoma.
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    Genotyping Cancer-Associated Genes in Chordoma Identifies Mutations in Oncogenes and Areas of Chromosomal Loss Involving CDKN2A, PTEN, and SMARCB1
    (Public Library of Science, 2014) Choy, Edwin; MacConaill, Laura; Cote, Gregory; Le, Long P.; Shen, Jacson K.; Nielsen, Gunnlaugur; Iafrate, Anthony; Garraway, Levi; Hornicek, Francis; Duan, Zhenfeng
    The molecular mechanisms underlying chordoma pathogenesis are unknown. We therefore sought to identify novel mutations to better understand chordoma biology and to potentially identify therapeutic targets. Given the relatively high costs of whole genome sequencing, we performed a focused genetic analysis using matrix-assisted laser desorption/ionization-time of flight mass spectrometer (Sequenom iPLEX genotyping). We tested 865 hotspot mutations in 111 oncogenes and selected tumor suppressor genes (OncoMap v. 3.0) of 45 human chordoma tumor samples. Of the analyzed samples, seven were identified with at least one mutation. Six of these were from fresh frozen samples, and one was from a paraffin embedded sample. These observations were validated using an independent platform using homogeneous mass extend MALDI-TOF (Sequenom hME Genotyping). These genetic alterations include: ALK (A877S), CTNNB1 (T41A), NRAS (Q61R), PIK3CA (E545K), PTEN (R130), CDKN2A (R58*), and SMARCB1 (R40*). This study reports on the largest comprehensive mutational analysis of chordomas performed to date. To focus on mutations that have the greatest chance of clinical relevance, we tested only oncogenes and tumor suppressor genes that have been previously implicated in the tumorigenesis of more common malignancies. We identified rare genetic changes that may have functional significance to the underlying biology and potential therapeutics for chordomas. Mutations in CDKN2A and PTEN occurred in areas of chromosomal copy loss. When this data is paired with the studies showing 18 of 21 chordoma samples displaying copy loss at the locus for CDKN2A, 17 of 21 chordoma samples displaying copy loss at PTEN, and 3 of 4 chordoma samples displaying deletion at the SMARCB1 locus, we can infer that a loss of heterozygosity at these three loci may play a significant role in chordoma pathogenesis.
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    A-770041 reverses paclitaxel and doxorubicin resistance in osteosarcoma cells
    (BioMed Central, 2014) Duan, Zhenfeng; Zhang, Jianming; Ye, Shunan; Shen, Jacson; Choy, Edwin; Cote, Gregory; Harmon, David; Mankin, Henry; Hua, Yingqi; Zhang, Yu; Gray, Nathanael; Hornicek, Francis
    Background: Reversing multidrug resistance (MDR) has been an important goal for clinical and investigational oncologists. In the last few decades, significant effort has been made to search for inhibitors to reverse MDR by targeting ATP-binding cassette (ABC) transporters (Pgp, MRP) directly, but these efforts have achieved little clinical success. Protein kinases play important roles in many aspects of tumor cell growth and survival. Combinations of kinase inhibitors and chemotherapeutics have been observed to overcome cancer drug resistance in certain circumstances. Methods: We screened a kinase specific inhibitor compound library in human osteosarcoma MDR cell lines to identify inhibitors that were capable of reversing chemoresistance to doxorubicin and paclitaxel. Results: We identified 18 small molecules that significantly increase chemotherapy drug-induced cell death in human osteosarcoma MDR cell lines U-2OSMR and KHOSR2. We identified A-770041 as one of the most effective MDR reversing agents when combined with doxorubicin or paclitaxel. A-770041 is a potent Src family kinase (Lck and Src) inhibitor. Western blot analysis revealed A-770041 inhibits both Src and Lck activation and expression. Inhibition of Src expression in U-2OSMR and KHOSR2 cell lines using lentiviral shRNA also resulted in increased doxorubicin and paclitaxel drug sensitivity. A-770041 increases the intracellular drug accumulation as demonstrated by calcein AM assay. Conclusions: These results indicate that small molecule inhibitor A-770041 may function to reverse ABCB1/Pgp-mediated chemotherapy drug resistance. Combination of Src family kinase inhibitor with regular chemotherapy drug could be clinically effective in MDR osteosarcoma. Electronic supplementary material The online version of this article (doi:10.1186/1471-2407-14-681) contains supplementary material, which is available to authorized users.
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    Phase II study of olaparib in patients with refractory Ewing sarcoma following failure of standard chemotherapy
    (BioMed Central, 2014) Choy, Edwin; Butrynski, James E; Harmon, David; Morgan, Jeffrey A; George, Suzanne; Wagner, Andrew J; D’Adamo, David; Cote, Gregory; Flamand, Yael; Benes, Cyril; Haber, Daniel; Baselga, Jose M; Demetri, George
    Background: Preclinical studies have documented antitumor activity of PARP inhibition both in vitro and in vivo, against Ewing sarcoma cells. This study aimed to translate that observation into a clinical trial to assess the efficacy and tolerability of olaparib, a PARP inhibitor, in patients with advanced Ewing sarcoma (EWS) progressing after prior chemotherapy. Methods: In this nonrandomized phase II trial, adult participants with radiographically measureable metastatic EWS received olaparib tablets, 400 mg orally twice daily, until disease progression or drug intolerance. Tumor measurements were determined by CT or MRI at 6 and 12 weeks after starting olaparib administration, and then every 8 weeks thereafter. Tumor response determinations were made according to RECIST 1.1, and adverse event determinations were made according to CTCAE, version 4.0. A total of 22 participants were planned to be enrolled using a conventional 2-step phase II study design. If no objective responses were observed after 12 participants had been followed for at least 3 months, further accrual would be stopped. Results: 12 participants were enrolled, and all were evaluable. There were no objective responses (PR/CR), 4 SD (duration 10.9, 11.4, 11.9, and 17.9 wks), and 8 PD as best response. Of the SD, 2 had minor responses (−9% and −11.7% by RECIST 1.1). The median time to disease progression was 5.7 weeks. Further enrollment was therefore discontinued. No significant or unexpected toxicities were observed with olaparib, with only a single case each of grade 3 anemia and grade 3 thrombocytopenia observed. Conclusions: This study is the first report of a prospective phase II trial to evaluate the safety and efficacy of a PARP inhibitor in patients with advanced Ewing sarcoma after failure of standard chemotherapy. Olaparib administration was safe and well tolerated when administered to this small heavily pre-treated cohort at the 400 mg BID dose, although the median duration of dosing was for only 5.7 weeks. No significant responses or durable disease control was seen, and the short average interval to disease progression underscores the aggressiveness of this disease. Other studies to combine cytotoxic chemotherapy with PARP inhibition in EWS are actively ongoing. Trial registration ClinicalTrials.gov Identifier: NCT01583543
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    MDR1 siRNA loaded hyaluronic acid-based CD44 targeted nanoparticle systems circumvent paclitaxel resistance in ovarian cancer
    (Nature Publishing Group, 2015) Yang, Xiaoqian; lyer, Arun K.; Singh, Amit; Choy, Edwin; Hornicek, Francis; Amiji, Mansoor M.; Duan, Zhenfeng
    Development of multidrug resistance (MDR) is an almost universal phenomenon in patients with ovarian cancer, and this severely limits the ultimate success of chemotherapy in the clinic. Overexpression of the MDR1 gene and corresponding P-glycoprotein (Pgp) is one of the best known MDR mechanisms. MDR1 siRNA based strategies were proposed to circumvent MDR, however, systemic, safe, and effective targeted delivery is still a major challenge. Cluster of differentiation 44 (CD44) targeted hyaluronic acid (HA) based nanoparticle has been shown to successfully deliver chemotherapy agents or siRNAs into tumor cells. The goal of this study is to evaluate the ability of HA-PEI/HA-PEG to deliver MDR1 siRNA and the efficacy of the combination of HA-PEI/HA-PEG/MDR1 siRNA with paclitaxel to suppress growth of ovarian cancer. We observed that HA-PEI/HA-PEG nanoparticles can efficiently deliver MDR1 siRNA into MDR ovarian cancer cells, resulting in down-regulation of MDR1 and Pgp expression. Administration of HA-PEI/HA-PEG/MDR1 siRNA nanoparticles followed by paclitaxel treatment induced a significant inhibitory effect on the tumor growth, decreased Pgp expression and increased apoptosis in MDR ovarian cancer mice model. Our findings suggest that CD44 targeted HA-PEI/HA-PEG/MDR1 siRNA nanoparticles can serve as a therapeutic tool with great potentials to circumvent MDR in ovarian cancer.
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    Targeting programmed cell death ligand 1 by CRISPR/Cas9 in osteosarcoma cells
    (Impact Journals LLC, 2017) Liao, Yunfei; Chen, Lulu; Feng, Yong; Shen, Jacson; Gao, Yan; Cote, Gregory; Choy, Edwin; Harmon, David; Mankin, Henry; Hornicek, Francis; Duan, Zhenfeng
    Programmed cell death ligand 1 (PD-L1) is a transmembrane protein that is expressed on tumor cells that suppresses the T cell-mediated immune response. Therapies targeting the PD-L1 pathway promote anti-tumor immunity and have shown promising results in some types of cancers. However, the functional and therapeutic roles of PD-L1 in osteosarcoma remain largely unknown. In this study, we found that PD-L1 protein was expressed in osteosarcoma cell lines and tissue microarray of patient tumors. Tissue microarray immunohistochemistry analysis showed that the overall and five-year survival rates of patients with high levels of PD-L1 expression were significantly shorter than patients with low levels. High levels of PD-L1 expression were also associated with metastasis in osteosarcoma patients. Furthermore, we applied the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 system to target PD-L1 gene at the DNA level in osteosarcoma cell lines. We found that the expression of PD-L1 could be efficiently disrupted by CRISPR/Cas9 system and PD-L1 knockdown increased drug sensitivities for doxorubicin and paclitaxel. These results suggest that PD-L1 is an independent prognostic factor in osteosarcoma and that PD-L1 knockout by CRISPR/Cas9 may be a therapeutic approach for the treatment of osteosarcoma.
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    Pharmacokinetics and tolerability of NSC23925b, a novel P-glycoprotein inhibitor: preclinical study in mice and rats
    (Nature Publishing Group, 2016) Gao, Yan; Shen, Jacson K.; Choy, Edwin; Zhang, Zhan; Mankin, Henry; Hornicek, Francis; Duan, Zhenfeng
    Overexpression of P-glycoprotein (Pgp) increases multidrug resistance (MDR) in cancer, which greatly impedes satisfactory clinical treatment and outcomes of cancer patients. Due to unknown pharmacokinetics, the use of Pgp inhibitors to overcome MDR in the clinical setting remains elusive despite promising in vitro results. The purpose of our current preclinical study is to investigate the pharmacokinetics and tolerability of NSC23925b, a novel and potent P-glycoprotein inhibitor, in rodents. Plasma pharmacokinetic studies of single-dose NSC23925b alone or in combination with paclitaxel or doxorubicin were conducted in male BALB/c mice and Sprague-Dawley rats. Additionally, inhibition of human cytochrome P450 (CYP450) by NSC23925b was examined in vitro. Finally, the maximum tolerated dose (MTD) of NSC23925b was determined. NSC23925b displayed favorable pharmacokinetic profiles after intraperitoneal/intravenous (I.P./I.V.) injection alone or combined with chemotherapeutic drugs. The plasma pharmacokinetic characteristics of the chemotherapy drugs were not affected when co-administered with NSC23925b. All the animals tolerated the I.P./I.V. administration of NSC23925b. Moreover, the enzymatic activity of human CYP450 was not inhibited by NSC23925b. Our results demonstrated that Pgp inhibitor NSC23925b exhibits encouraging preclinical pharmacokinetic characteristics and limited toxicity in vivo. NSC23925b has the potential to treat cancer patients with MDR in the future.
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    An imprinted non-coding genomic cluster at 14q32 defines clinically relevant molecular subtypes in osteosarcoma across multiple independent datasets
    (BioMed Central, 2017) Hill, Katherine E.; Kelly, Andrew D.; Kuijjer, Marieke L.; Barry, William; Rattani, Ahmed; Garbutt, Cassandra C.; Kissick, Haydn; Janeway, Katherine; Perez-Atayde, Antonio; Goldsmith, Jeffrey; Gebhardt, Mark; Arredouani, Mohamed S.; Cote, Greg; Hornicek, Francis; Choy, Edwin; Duan, Zhenfeng; Quackenbush, John; Haibe-Kains, Benjamin; Spentzos, Dimitrios
    Background: A microRNA (miRNA) collection on the imprinted 14q32 MEG3 region has been associated with outcome in osteosarcoma. We assessed the clinical utility of this miRNA set and their association with methylation status. Methods: We integrated coding and non-coding RNA data from three independent annotated clinical osteosarcoma cohorts (n = 65, n = 27, and n = 25) and miRNA and methylation data from one in vitro (19 cell lines) and one clinical (NCI Therapeutically Applicable Research to Generate Effective Treatments (TARGET) osteosarcoma dataset, n = 80) dataset. We used time-dependent receiver operating characteristic (tdROC) analysis to evaluate the clinical value of candidate miRNA profiles and machine learning approaches to compare the coding and non-coding transcriptional programs of high- and low-risk osteosarcoma tumors and high- versus low-aggressiveness cell lines. In the cell line and TARGET datasets, we also studied the methylation patterns of the MEG3 imprinting control region on 14q32 and their association with miRNA expression and tumor aggressiveness. Results: In the tdROC analysis, miRNA sets on 14q32 showed strong discriminatory power for recurrence and survival in the three clinical datasets. High- or low-risk tumor classification was robust to using different microRNA sets or classification methods. Machine learning approaches showed that genome-wide miRNA profiles and miRNA regulatory networks were quite different between the two outcome groups and mRNA profiles categorized the samples in a manner concordant with the miRNAs, suggesting potential molecular subtypes. Further, miRNA expression patterns were reproducible in comparing high-aggressiveness versus low-aggressiveness cell lines. Methylation patterns in the MEG3 differentially methylated region (DMR) also distinguished high-aggressiveness from low-aggressiveness cell lines and were associated with expression of several 14q32 miRNAs in both the cell lines and the large TARGET clinical dataset. Within the limits of available CpG array coverage, we observed a potential methylation-sensitive regulation of the non-coding RNA cluster by CTCF, a known enhancer-blocking factor. Conclusions: Loss of imprinting/methylation changes in the 14q32 non-coding region defines reproducible previously unrecognized osteosarcoma subtypes with distinct transcriptional programs and biologic and clinical behavior. Future studies will define the precise relationship between 14q32 imprinting, non-coding RNA expression, genomic enhancer binding, and tumor aggressiveness, with possible therapeutic implications for both early- and advanced-stage patients. Electronic supplementary material The online version of this article (doi:10.1186/s13045-017-0465-4) contains supplementary material, which is available to authorized users.
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    Androgen receptor is a potential novel prognostic marker and oncogenic target in osteosarcoma with dependence on CDK11
    (Nature Publishing Group, 2017) Liao, Yunfei; Sassi, Slim; Halvorsen, Stefan; Feng, Yong; Shen, Jacson; Gao, Yan; Cote, Gregory; Choy, Edwin; Harmon, David; Mankin, Henry; Hornicek, Francis; Duan, Zhenfeng
    Osteosarcoma is the most common bone cancer in children and adolescents. Previously, we have found that cyclin-dependent kinase 11 (CDK11) signaling was essential for osteosarcoma cell growth and survival. Subsequently, CDK11 siRNA gene targeting, expression profiling, and network reconstruction of differentially expressed genes were performed between CDK11 knock down and wild type osteosarcoma cells. Reconstructed network of the differentially expressed genes pointed to the AR as key to CDK11 signaling in osteosarcoma. CDK11 increased transcriptional activation of AR gene in osteosarcoma cell lines. AR protein was highly expressed in various osteosarcoma cell lines and patient tumor tissues. Tissue microarray analysis showed that the disease-free survival rate for patients with high-expression of AR was significantly shorter than for patients with low-expression of AR. In addition, AR gene expression knockdown via siRNA greatly inhibited cell growth and viability. Similar results were found in osteosarcoma cells treated with AR inhibitor. These findings suggest that CDK11 is involved in the regulation of AR pathway and AR can be a potential novel prognostic marker and therapeutic target for osteosarcoma treatment.
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    Expression of programmed cell death ligand 1 (PD-L1) and prevalence of tumor-infiltrating lymphocytes (TILs) in chordoma
    (Impact Journals LLC, 2015) Feng, Yong; Shen, Jacson; Gao, Yan; Liao, Yunfei; Cote, Gregory; Choy, Edwin; Chebib, Ivan; Mankin, Henry; Hornicek, Francis; Duan, Zhenfeng
    Chordomas are primary malignant tumors of the notochord that are resistant to conventional chemotherapy. Expression of programmed cell death ligand 1 (PD-L1), prevalence of tumor-infiltrating lymphocytes (TILs), and their clinical relevance in chordoma remain unknown. We evaluated PD-L1 expression in three chordoma cell lines and nine chordoma tissue samples by western blot. Immunohistochemical staining was performed on a chordoma tissue microarray (TMA) that contained 78 tissue specimens. We also correlated the expression of PD-L1 and TILs with clinical outcomes. PD-L1 protein expression was demonstrated to be induced by IFN-γ in both UCH1 and UCH2 cell lines. Across nine human chordoma tissue samples, PD-L1 protein was differentially expressed. 94.9% of chordoma samples showed positive PD-L1 expression in the TMA. The expression score of PD-L1 for metastatic chordoma tumors was significant higher as compared with non-metastatic chordoma tumors. Expression of PD-L1 protein significantly correlates with the presence of elevated TILs, which correlates with metastasis. In summary, our study showed high levels of PD-L1 are expressed in chordoma, which is correlated with the prevalence of TILs. The current study suggests targeting PD-L1 may be a novel immunotherapeutic strategy for chordoma clinical trials.