Sarcoma Genome Project (Phase I) Genome-Wide Molecular Genetic Analysis of 7 Sarcoma Types
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Liposarcoma Genomic Alterations Define New Targets for Therapy Samuel Singer, MD Memorial Sloan-Kettering Cancer Center Sarcoma Disease Management Program Chief Gastric and Mixed Tumor Service Liposarcoma • ~20% of 12,000 new STS cases in US each year, the majority are sporadic • Distinct cytogenetic subgroups comprising 5 subtypes • Simple (translocation-associated) − Myxoid and round cell liposarcoma: >90% t(12;16) • Complex rearrangements (alterations in cell cycle genes and checkpoint defects) – Well-differentiated and Dedifferentiated liposarcoma: ~90% 12q amplification – Pleomorphic liposarcoma • Genetic events associated with liposarcomagenesis remain undiscovered Therapeutic Challenges • More than 60% of patients with newly diagnosed liposarcoma eventually die of disease • Diverse histopathology and biological behavior • WDLS and DDLS are not very responsive to chemotherapy • Pressing need to develop subtype specific molecularly targeted therapeutics for patients with advanced/recurrent disease Histologic distribution of Liposarcoma subtype MSKCC Clinical Sarcoma Database 1772 liposarcoma patients over 29 years (1982–2011) Site‐specific histologic subtype distribution WD Sarcoma Genome Project (Phase I) Genome-wide molecular genetic analysis of 7 sarcoma types (Phase I) DNA copy number + LOH 207 sarcomas and Sequencing 225 matched normals genes and 451 Clinical microRNAs annotation database Transcriptional changes (MSKCC) (protein-coding genes) Functional genetic screen of amplified genes in DDLPS Sarcoma Genome Project (Phase I) Analysis of DNA sequence in 6 sarcoma types • Kit in GIST was the most frequently mutated gene • Next most frequently mutated genes in more than 5% of samples within a subtype were: genes sarcoma type % of samples drug able mutated mutated target PIK3CA myxoid/round cell 18 % PI3K inhibitors liposarcoma TP53 pleomorphic 17 % Small molecules liposarcoma that reactivate mutant p53 (PRIMA-1) NF1 myxofibrosarcoma 10.5 % MEK or mTOR inhibitors pleomorphic 8 % liposarcoma PIK3CA mutations in myxoid/round cell liposarcoma are associated with shorter disease- specific survival compared with wildtype (p-value = 0.036) E545K helical-domain mutations were associated with increased Akt phosphorylation relative to wildtype in myxoid/round cell liposarcoma TORC2 phosphorylation site PDK1 phosphorylation site Nucleotide and Copy-number alterations in Dedifferentiated Liposarcoma (n=50) and myxoid/round cell liposarcoma (n=21) • Consensus plot of statistically significant genome-wide copy-number alterations assessed by RAE Knockdown of the Dedifferentiated Liposarcoma “Amplicome” as a Functional Screen for Potential Driver Genes • Which amplified genes in DDLS are necessary for cancer cell proliferation and survival? – Genomics-driven RNAi screen in 3 genotype-matched DDLS cell lines – Systematic knockdown with shRNAs on 385 significantly amplified genes – 99 genes whose knockdown decreased cell growth, 27 of 99 were amplified in at least one cell line Functional Validation of CDK4 as a Therapeutic Target in DDLS Effect of three validated shRNAs targeting 1m selective CDK4/CDK6 CDK4 on the proliferation of two DDLS cell inhibitor PD0332991 induces a lines G1 growth arrest and senescence Therapeutics for DDLS • Potential targets: MDM2 antagonists Apoptosis Following 48hr Nutlin Treatment No Drug 60 • Nutlin-3 5uM Nutlin – MDM2 50 40 • Roche (R7112) – 30 20 10 prevents MDM2-p53 Annexin Annexin / / % % Apoptosis Apoptosis 0 interaction NADIP DDLS LS141 – CDK4 CDK4/CDK6 inhibitor senescence associated heterochromatic foci • PD0332991 – G1 arrest and senescence – AURKA AURKA inhibitor DDLS ND DDLS AK (5 µM) • MLN8237 – oral, ATP- competitive, disrupts assembly of mitotic spindle – mitotic delay – …other kinases (IRAK3, PCTK2)? Multi-center phase I trial of R7112 in patients with advanced malignancies • R7112 (Roche) is a small molecule antagonist of MDM2 – binds to the p53 site on the surface of MDM2 and blocks protein-protein interaction between MDM2 and p53 wt protein • Oral administration – MTD: 2500 mg/day, BID x 10 days with 18 days of rest associated with significant thrombocytopenia • Dosing schedule revised to 2500 mg/day, QD dosing x 5 days with 23 days rest • 20 patients with WDLS and DDLS treated to date on BID dosing schedule – 8 with stable disease at 8 weeks • Molecular and pharmacokinetic analysis – p53 mutation, MDM2 levels Phase II clinical trial of PD0332991 in patients with WDLS/DDLS that have CDK4 amplification by FISH and express the Rb protein by IHC • Patients with locally advanced, recurrent or metastatic WDLS or DDLS and disease progression on one prior systemic therapy • PD0332991 dose of 200 mg PO QD for 14 days, followed by 7 days of rest. – safe and tolerable in a phase I study – In phase 1 study two patients with advanced WDLS had stable disease for 3.1 and 2.3 years • Primary endpoint: patients who are progression-free at 12 weeks Phase II clinical trial of MLN8237 in patients with WDLS/DDLS and pleomorphic liposarcoma • Test a second-generation selective AURKA inhibitor in patients with advanced / metastatic liposarcoma • Primary objective: response rate (CR + PR) assessed at 12 weeks • Based on a completed phase I study, patients will be treated with MLN8237 50mg PO BID for 7 days, followed by 14 days of rest. Treatment is repeated every 3 weeks (one cycle) Sarcoma Genome Project (Phase II) • Perform a genome-wide genetic and functional analysis of well-differentiated (WDLS) and dedifferentiated (DDLS) Liposarcoma to identify: • distinct genomic subtypes • molecular markers that associate with outcome and pathologic features • genetic alterations associated with sarcoma progression • subtype specific therapeutic targets MSKCC Rockefeller BROAD Samuel Singer Thomas Tuschl Matthew Meyerson Marc Ladanyi Markus Hafner Jordi Barretina Chris Sander Alex Ramos Barry Taylor Shantanu Banerji Sample procurement and microRNA profiling Systematic shRNA screens selection / RNA and DNA extraction microRNA cloning and sequencing Solexa single molecule cDNA sequencing U133A Affy transcript arrays microRNA ISH 244K Agilent CGH array, Validation of candidate fusion array mutations Agilent microRNA array Computational analysis for protein-coding genes, microRNAs, amplified genes, gene rearrangements, activating mutations and activated pathways microRNA functional analysis Validate genetic, genomic and functional alterations Well-differentiated and Dedifferentiated Liposarcoma Disease-specific survival for primary Local recurrence-free survival for primary retroperitoneal liposarcoma: WDLS vs. DDLS retroperitoneal liposarcoma: WDLS vs. DDLS Data from MSKCC Sarcoma Database (n=345, 7/1/82 to 6/30/2010) • Resistant to chemotherapy • Can we exploit differentially expressed microRNAs as therapeutic targets for this deadly disease? Role of miRNAs in liposarcomagenesis • miRNAs regulate cell proliferation, apoptosis, and differentiation • miRNAs are abnormally regulated in cancer – may serve as oncogenes but generally down-regulated in tumors compared to normal tissue – inhibiting miRNA processing enhances tumorigenesis suggest miRNAs act mainly as tumorsuppressors • Profile miRNAs in normal fat (NF), WDLS and DDLS tissue samples to identify miRNAs that associate tissue type and tumor progression – Agilent microarrays (17 NF, 32 WDLS, 30 DDLS) – Deep sequencing of small RNA cDNA libraries (11 NF, 22 WDLS, 22 DDLS) Small RNA cDNA library preparation for sequencing • Developed a set of bar-coded sequencing adapters • parallel sequencing of up to 20 samples in one Solexa sequencing run, from < 2 µg total RNA / sample • > 200,000 sequence reads / sample at a lower cost than miRNA microarrays • map small RNAs to the genome; annotate by functional type • convert cloning frequencies to miRNA expression levels Hafner, M., Tuschl, T. Methods 2008 44:3-12 Unsupervised clustering of miRNAs in normal fat, WDLS and DDLS samples analyzed by deep sequencing DDLPS Normal fat tissue WDLPS Deep sequencing compared to Agilent microarray (DDLS / NF) miR-21 and and miR-26a are significantly over- expressed in DDLS compared to normal fat miR-21 miR-26a PTEN expression Normalized Counts Normalized NF WD DD NF WD DD NF WD DD miR-26a-2 encoded in the intron of CTDSP2, adjacent to CDK4 on chr12, is amplified in 88% of DDLS miR-143 and miR-145 are down-regulated in WDLS and DDLS compared to NF • miR-143 - most strongly expressed miRNA in normal fat (8% of total) • miR-143 and miR-145 located within 1.8 kb of each other on 5q miR‐143 miR‐145 Normalized Counts Normalized N WD DD N WD DD miR‐143F Fold FDR miRF‐145 Fold FDR Change Change WD/NF ‐3.3 1.5e‐5 WD/NF ‐2.8 > 0.05 DD/NF ‐7.9 4.0e‐12 DD/NF ‐6.6 3.2e‐7 FDR= false discovery rate miR-143 and miR-145 are down-regulated in WDLS and DDLS cell lines compared to ASCs by deep sequencing and quantitative PCR In situ hybridization for miR-143 DDLS cell lines WDLS cell lines DDLS cell lines WDLS cell lines A lentiviral system was used for stable re-expression of miR-143 and miR-145 in liposarcoma cell lines miRNA precursor in Tranform E. coli Culture and extract Transfect HEK293T lentiviral vector cells plasmid DNA Cells miR‐143; miR‐145 re‐ expression Harvest viral Functional supernatant Studies Select with Puromycin Infect cells of interest (Day 1) (Day 0) Re-expression of miR-143 inhibits proliferation in two DDLS cell lines DNA content (relative to day 2) (relative to day Time (Days) Time (Days) Re-expression of miR-143, but not miR-145, induces apoptosis in DDLS cells DDLS14 DDLS8817