- Email: [email protected]
617. Effects of Combination Therapy of Conditionally Replicating Relaxin-Expressing Adenovirus with Radiation
Cancer - Targeted Gene Therapy: Angiogenesis, Combination Therapies and Bioinformatics indicated significant tumor-free survival following rAAV-(E+A) therapy only when the vector was given at earlier time (10 weeks) compared to treatment at 18 weeks. In the present study, we evaluated the expression profiles of angiogenesis-related genes in prostate cancer at different stages of tumor growth and following treatment with rAAV-(E+A). Comparison of gene expression in moderately differentiated tumors of naïve and rAAV-(E+A) treated mice indicated a significant down regulation in the expression of Adra 2b, EphA2, FGF and FGF receptor, Mdk, MMP2, MMP9, VEGF-related genes, PDGF, Pecam1, Ptn, TGFβ. Early stage of prostate cancer was found to be more sensitive for endostatin therapy than advanced stage lesion. To further discern possible mechanisms of this therapy during the transition phase of tumor progression, studies were performed using androgen-sensitive (LNCaP) and androgen-independent (PC3 and Du145) human prostate cancer cells. Endostatin treatment was given either as purified protein or by gene transfer using a plasmid vector. Results of these studies indicated that in androgen-sensitive cell line, there was a significant decrease in the expression of not only the aforementioned genes, but also kinases: RhoA, Ras, phosphoERK1/2 and NFkB following endostatin protein treatment and plasmid transfection. Whereas cell proliferation and apoptosis were not influenced by endostatin treatment, migration was significantly decreased by endostatin treatment, only in the androgen-sensitive cell line. There was no significant response to purified endostatin treatment in the androgen independent cell lines. However, forced overexpression of endostatin by plasmid transfection into androgen independent prostate cancer cell lines resulted in the downregulation of aforesaid kinanses and decreased proliferation rate and migration. A significant decrease in androgen receptor expression was observed following endostatin treatment in vitro in both LNCaP and PC3 cells and in the prostate tissues of TRAMP mice in vivo. Results of these studies suggest the role of androgen receptor signaling in endostatin therapy during early stages of prostate cancer and identified possible targets of endostatin during the disease progression.
616. Using Gene and Protein Sequence Properties for Target Selection and Validation for Personalized RNAi Cancer Therapy
John S. Vorhies,1,2 Rachel Adams,2 Neil Senzer,1,2,3,4 John J. Nemunaitis.1,2,3,4 1 Mary Crowley Cancer Research Centers, Dallas, TX; 2Gradalis, Inc., Dallas, TX; 3Texas Oncology, P.A., Dallas, TX; 4Baylor Sammons Cancer Center, Dallas, TX. Sequence properties of a given gene and its protein product can be valuable in predicting its potential association with cancer. Properties such as the extent of cross species preservation, paralogy and sequence length have been employed in algorithms designed to screen genomes for novel disease genes. In general, key disease proteins are characterized by longer length of their amino acid sequences, several specific preservation and paralogy profiles compared with human proteins, as well as broader phylogenetic extent among other species. Computational and statistical disease gene prioritization methods have been shown to effectively refine genome-wide data sets into smaller sets of candidate disease genes. Specific application of these methods to prediction of cancer genes has also been proposed and tested. Here we investigate the potential of sequence properties to aid in the process of target selection and validation for personalized RNA interference (RNAi) based gene therapy. Using a systems biology molecular networks database we examine the variations in sequence properties of proteins overexpressed in human tumor tissue as compared to normal tissue in the context of their connectivity within intracellular signal transduction networks. In addition, we propose a new process to compute a cross species preservation score (csps) of a given protein. This score is a comparison of the mutation rate of the protein in question compared to the estimated S230
average mutation rate of a protein during evolution. The csps is a weighted compilation of a length independent conservation score of the protein and its homologs within those eukaryotes whose genomes have been completely sequenced. We have calculated csps for the proteins overexpressed in human cancer tissue with reference to those eukaryotes whose genomes have been completely sequenced. Using the systems biology molecular networks database Pathway Studio ® we examined the connectivity the proteins within intracellular signal transduction networks, giving attention to the total number of interactions in the first second and third order as well as the type and directionality of interactions in the first order. We then analyzed the covariance in these independent datasets to determine the utility of sequence properties in personalized target selection for RNAi. The csps and other sequence properties could be useful in validating the effectiveness of a transcript as an RNAi target not only by hinting at its potential involvement in cancer but also the likelihood that it is a node within crucial cancer related signalling architecture. These properties help predict whether attenuation of its expression would result in catastrophic failure of cell machinery.
617. Effects of Combination Therapy of Conditionally Replicating Relaxin-Expressing Adenovirus with Radiation
Minjung Kim,1 Jaesung Kim,1 Ji Young Yoo,1 Chae-Ok Yun,1 JooHang Kim.1 1 Brain Korea 21 Project for Medical Science, Institute for Cancer Research, Yonsei Cancer Center, Seoul, Republic of Korea. Although traditional treatments such as radiation have been rapidly advanced, their therapeutic efficacy is limited by resistance of cancer cells to radiation. To overcome those problems, combined therapy of radiation with oncolytic adenoviruses has been reported and currently is being developed to clinical trials. Relaxin had been known to play a role in matrix degradation, so we previously generated relaxin-expressing oncolytic Ad to improve the capability of oncolytic virus itself. It was demonstrated that conditionally replicating relaxin-expressing Ad increased viral spreading by degradation of extracellular matrix (ECM) which act as a cellular barrier against virus and then enhanced tumor penetration. As a result, relaxin-expressing oncolytic Ad inhibited tumor growth and metastasis, and increased the survival of tumor-bearing mice. Therefore, we investigated whether combination therapy of relaxin-expressing Ad with radiation could complementarily overcome the limitation and improve anti-tumor efficacy. Conditionally replicating relaxin-expressing Ad, YDC002, used in this work is characterized by 1) regulation by modified human telomerase reverse transcriptase (mTERT) promoter for cancer specificity, 2) deletion of E1B 19KDa for strong cell killing efficacy, and 3) expression of relaxin for enhancement of Ad spreading by degradation of ECM and apoptotic effects. Combination of YDC002 with radiation showed more potent and faster cell killing effect than single therapy like radiation only or viral therapy only in the cancer cell lines tested. And this combination induced significant apoptotic effects, so it inhibited tumor growth. Especially, anti-tumor effects of YDC002 with radiation was higher than Gendicine, replicationincompetent Ad which express p53, or ONYX-015, E1B55 KDadeleted replication-competent Ad. Combination of YDC002 with radiation may be useful therapeutic modality by elevating anti-tumor effects.
Molecular Therapy Volume 16, Supplement 1, May 2008 Copyright © The American Society of Gene Therapy
616. Using Gene and Protein Sequence Properties for Target Selection and Validation for Personalized RNAi Cancer Therapy
John S. Vorhies,1,2 Rachel Adams,2 Neil Senzer,1,2,3,4 John J. Nemunaitis.1,2,3,4 1 Mary Crowley Cancer Research Centers, Dallas, TX; 2Gradalis, Inc., Dallas, TX; 3Texas Oncology, P.A., Dallas, TX; 4Baylor Sammons Cancer Center, Dallas, TX. Sequence properties of a given gene and its protein product can be valuable in predicting its potential association with cancer. Properties such as the extent of cross species preservation, paralogy and sequence length have been employed in algorithms designed to screen genomes for novel disease genes. In general, key disease proteins are characterized by longer length of their amino acid sequences, several specific preservation and paralogy profiles compared with human proteins, as well as broader phylogenetic extent among other species. Computational and statistical disease gene prioritization methods have been shown to effectively refine genome-wide data sets into smaller sets of candidate disease genes. Specific application of these methods to prediction of cancer genes has also been proposed and tested. Here we investigate the potential of sequence properties to aid in the process of target selection and validation for personalized RNA interference (RNAi) based gene therapy. Using a systems biology molecular networks database we examine the variations in sequence properties of proteins overexpressed in human tumor tissue as compared to normal tissue in the context of their connectivity within intracellular signal transduction networks. In addition, we propose a new process to compute a cross species preservation score (csps) of a given protein. This score is a comparison of the mutation rate of the protein in question compared to the estimated S230
average mutation rate of a protein during evolution. The csps is a weighted compilation of a length independent conservation score of the protein and its homologs within those eukaryotes whose genomes have been completely sequenced. We have calculated csps for the proteins overexpressed in human cancer tissue with reference to those eukaryotes whose genomes have been completely sequenced. Using the systems biology molecular networks database Pathway Studio ® we examined the connectivity the proteins within intracellular signal transduction networks, giving attention to the total number of interactions in the first second and third order as well as the type and directionality of interactions in the first order. We then analyzed the covariance in these independent datasets to determine the utility of sequence properties in personalized target selection for RNAi. The csps and other sequence properties could be useful in validating the effectiveness of a transcript as an RNAi target not only by hinting at its potential involvement in cancer but also the likelihood that it is a node within crucial cancer related signalling architecture. These properties help predict whether attenuation of its expression would result in catastrophic failure of cell machinery.
617. Effects of Combination Therapy of Conditionally Replicating Relaxin-Expressing Adenovirus with Radiation
Minjung Kim,1 Jaesung Kim,1 Ji Young Yoo,1 Chae-Ok Yun,1 JooHang Kim.1 1 Brain Korea 21 Project for Medical Science, Institute for Cancer Research, Yonsei Cancer Center, Seoul, Republic of Korea. Although traditional treatments such as radiation have been rapidly advanced, their therapeutic efficacy is limited by resistance of cancer cells to radiation. To overcome those problems, combined therapy of radiation with oncolytic adenoviruses has been reported and currently is being developed to clinical trials. Relaxin had been known to play a role in matrix degradation, so we previously generated relaxin-expressing oncolytic Ad to improve the capability of oncolytic virus itself. It was demonstrated that conditionally replicating relaxin-expressing Ad increased viral spreading by degradation of extracellular matrix (ECM) which act as a cellular barrier against virus and then enhanced tumor penetration. As a result, relaxin-expressing oncolytic Ad inhibited tumor growth and metastasis, and increased the survival of tumor-bearing mice. Therefore, we investigated whether combination therapy of relaxin-expressing Ad with radiation could complementarily overcome the limitation and improve anti-tumor efficacy. Conditionally replicating relaxin-expressing Ad, YDC002, used in this work is characterized by 1) regulation by modified human telomerase reverse transcriptase (mTERT) promoter for cancer specificity, 2) deletion of E1B 19KDa for strong cell killing efficacy, and 3) expression of relaxin for enhancement of Ad spreading by degradation of ECM and apoptotic effects. Combination of YDC002 with radiation showed more potent and faster cell killing effect than single therapy like radiation only or viral therapy only in the cancer cell lines tested. And this combination induced significant apoptotic effects, so it inhibited tumor growth. Especially, anti-tumor effects of YDC002 with radiation was higher than Gendicine, replicationincompetent Ad which express p53, or ONYX-015, E1B55 KDadeleted replication-competent Ad. Combination of YDC002 with radiation may be useful therapeutic modality by elevating anti-tumor effects.
Molecular Therapy Volume 16, Supplement 1, May 2008 Copyright © The American Society of Gene Therapy