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Gene expression studies of breast tumors with different responses to immunotherapy. Elizabeth Chun MSc. Candidate Jones Lab, The Genome Sciences Centre 2009. 11. 26. Adoptive T-cell Transfer Immunotherapy. Isolation of antigen-specific T-lymphocytes from a cancer patient
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Gene expression studies of breast tumors with different responses to immunotherapy Elizabeth Chun MSc. Candidate Jones Lab, The Genome Sciences Centre 2009. 11. 26.
Adoptive T-cell Transfer Immunotherapy Isolation of antigen-specific T-lymphocytes from a cancer patient Ex vivo expansion and activation of T-lymphocytes Transfer of anti-tumor T-lymphocytes back to the patient Several attractive tumor antigens e.g. Her2/neu Low efficacy of immunotherapy Many factors limiting immune response Gattinoni L. et al. (2006) Nature Reviews in Immunology. 6:383-393.
Mouse model ACT Cysteine-rich domain Extracellular NOP-21 CR Tyrosine-kinase domain PR PD Neu+/p53- mouse C57BL/6J NOP-12, 23 CD8+ epitope CD4+ epitope NOP-6,17,18 NOP cell lines generated Affymetrix MoEx-1_0-st-v1 Neu+ mouse Mouse image from http://www.taconic.com/user-assets/Images/Producs-Services/em_mod_black.jpg Mammary tumor image from http://www.nature.com/onc/journal/v25/n54/images/1209707f4.jpg Affymetrix chip image from http://www.molecularstation.com/molecular-biology-images/data/508/affymetrix-microarray.jpg SOLiD sequencing – miRNA, transcriptome
Class specific DE genes • DE genes are detected by a bio-conductor tool, siggenes, using the Significance Analysis of Microarray (SAM) at FDR 10% or 15% • Detection of class-specific DE genes • the variation of gene expression between classes is greater than within the class • E.g. CR-specific DE genes E. g. PR-specific DE genes E.g. PD-specific DE genes ??? But interesting still…
Overlap from pair-wise comparisons and combined classes • Overlap of the “class-specific” gene sets found by the two-way pair-wise comparison and the comparison against the combined classes CR-specific PR-specific 229 42 CR vs (PR and PD) (N= 293) CR vs PD (N = 1242) PR vs PD (N = 1466) PR vs (CR and PD) (N= 47) PR vs PD (N = 1466) CR vs PD (N = 1242) PD-specific 899 PD vs (CR and PR) (N= 3601) CR vs PD (N = 1242) CR vs PR (N = 31)
Class-specific pathway analysis • Class-specific DE genes in CR and PD • CR: N = 229 • PD: N = 889 • DAVID (KEGG, BioCarta), Ingenuity tools used • Top pathways overlap in all three pathway databases • Common pathways found to be involved • Complement system: CR / PD • Pattern recognition: CR / PD • Stroma-related pathways: CR / PD • Class-specific pathways • CR-specific: TREM1 signaling; LXR/RXR activation • PD-specific: IL-3 signaling; FcyRIIB signaling; GM-CSF signaling; Leukocyte extravasation • 71 genes were selected for qRT-PCR by ranking by fold-change, involvement of > 1 pathways, found as good classifier by Predictive Analysis of Microarray (PAM)
Comparison with the human breast tumor data Select genes with 1-to-1 orthologous relationship with human (N = 15K) 1300 human intrinsic breast cancer gene set by Hu et al. (2006) (Agilent) • Collapse data from probe to gene level • Median for probes targeting a single gene 866 mouse intrinsic breast cancer gene set by Herschkowitz et al. (2007) (Agilent) Herschkowitz et al. (2007) • Merge human (HG-U133A from Rouzier et al. (2005)) and mouse (MoEx) breast tumor expression data • Batch correction by DWD Human (1300) Mouse (866) 106 Filter out genes probed in both MoEx and HG-U133 arrays (N = 8852) Cross-species intrinsic breast cancer gene sets (N = 106) 82 genes common to mouse-human breast cancer intrinsic gene sets in the merged dataset
Cluster analysis of mouse and human tumors • Hierarchical clustering on the subset of genes common to both species breast cancer intrinsic gene list PD PD PD PR PR CR Luminal A Her2-overexp Lum B Lum A Basal-like ER+ = 11/13 (85%) Her2- = 10/13 (77%) PR- = 7/12 (58%) ER- = 11/12 (92%) Her2+ = 8/12 (67%) PR- = 11/12 (92%) ER+ = 7/8 (88%) Her2+ = 6/8 (75%) PR+ = 6/8 (75%) ER+ = 28/32 (88%) Her2- = 26/32 (81%) PR+ = 19/30 (63%) ER- = 17/17 (100%) Her2- = 15/17 (88%) PR- = 13/17 (76%)
Ongoing research • Improve cluster analysis of mouse and human breast cancer data • Experimental validation of pathway-specific, class-specific DE genes by RT-qPCR • miRNA analysis from SOLiD data • Better alignment tools to account for adapter sequence • Identification of miRNA target genes and their functional enrichment • Correlation of target gene expression changes • WTSS data analysis from SOLiD data • Somatic point mutation survey of CR, PR, PD tumors • PCR validation of the putative mutations • Possible novel targets for tumor vaccine development
Acknowledgement Supervisor • Dr. Steven Jones Microarray Analysis • Dr. Allen Delaney The Deeley Research Centre • Dr. Brad Nelson • Dr. Michele Martin SOLiD WTSS Analysis • Dr. Inanc Birol • Nina Thiessen • Timothee Cezard SOLiD Library Construction & Sequencing • Dr. Martin Hirst • Yongjun Zhao • Thomas Zeng • Kevin Ma • Angela Tam ABI bioinformatics support • Dr. Yongming Sun LIMS & Systems team at GSC