SPOREs
Lung
Projects
Projects
Project 1: Genetic analysis of non-small cell lung cancer survival
Project Co-Leaders: David Christiani, MD, MPH (HSPH), John Wain, MD (MGH), and Rebecca Suk Heist, MD, MPH (MGH)
Project 1 will focus on identifying prognostic and predictive markers of survival in lung cancer. The ultimate goal of identifying such markers is to find ways to select the best treatment course for each patient. Recent studies by our group have demonstrated the importance of germline polymorphic variants as prognostic and predictive factors, but these studies have investigated only a few candidate polymorphisms relative to survival outcomes. In this SPORE renewal, we have adopted a high-density pathway approach to investigate more extensively and efficiently the role of entire pathways in survival outcomes. We selected pathways with biologic evidence for a role in tumor aggressiveness or treatment response. Although the eventual goal will be to evaluate germline DNA, serology, tumor-based tissue, and clinical factors in one cohesive model, at present we will focus on germline DNA to identify critical pathway markers. To achieve this goal, we will utilize a large (n=1,000), mature NSCLC case series, early and late stages, with annotated DNA and clinical data to assess genetic variation in selected pathways as prognostic and predictive markers in NSCLC. In Aim 1 (gene discovery), we will use the Illumina Bead Station GoldenGate assay system for genotyping of single nucleotide polymorphisms (SNPs), which allows large-scale genotyping for up to 1,536 customized SNPs, to systematically assess the effects of genetic variation in these pathways on survival outcomes in 60% of our large sample size (discovery phase). For polymorphisms that cannot be assayed with this system and for candidate genes to be used in a validation phase (Aim 2) on the whole population, we will utilize other in-house techniques in the Genomics Core, including Sequenom and ABI 7900 Taqman. Though our primary endpoint will be overall survival (OS), we will also assess disease-free survival (DFS) and progression-free survival (PFS), where appropriate. Aims 3-4 will include assessing the role of gender and other factors in the genetic predictors of survival among lung cancer patients, using both stratified and interaction analyses; and assessing additional candidate genes (e.g. EGFR) and pathways identified from companion basic and translational science studies (Projects 2–5) in lung cancer outcomes. The detailed clinical annotation of our case series is a unique resource with which to investigate prognostic and predictive markers, as well as for gene-environment interactions, in lung cancer survival.
Project 2: Foxa2 and C/EBP transcription factors in the pathogenesis and treatment of lung cancer
Project Co-Leaders: Daniel Tenen, MD (BIDMC), Daniel Costa, MD (BIDMC), and Balazs Halmos, MD (Case Western Reserve University)
Investigator: Susumu Kobayashi, MD, PhD (BIDMC)
Despite recent progress in diagnosis and treatment of non-small cell lung cancer (NSCLC), survival continues to be poor. Better understanding of the molecular mechanisms that lead to lung cancer and other malignancies are urgently necessary. Most of the research over the last decade in lung cancer has focused on oncogenes, as highlighted in Projects 3, 4, and 5 of this SPORE submission. However research regarding tumor suppressor genes involved in lung cancer has lagged behind, and no specific therapies targeting these genes have emerged to help patients. Since the original Lung Cancer SPORE proposal in 2002, we have studied two specific genes necessary for normal lung development that may act as tumor suppressor genes in lung cancer. These are the transcription factors C/EBPalpha and Foxa2. Our groups’ work has demonstrated that both factors act in a pathway commonly downregulated in many lung cancers and further experiments will enhance understanding of their clinical consequences. The goal of this research is to eventually devise therapies that can re-establish their differentiation-inducing and tumor suppressive pathways, which may expand the therapeutic and chemopreventive options for this malignancy. Therefore, based on the novel findings obtained in 2003 to 2007, we propose to further expand our studies of these transcription factors and move the pathways and potential targets closer to effective clinical applications in malignancies of the airway epithelium with the following Specific Aims: 1) To establish the main mechanisms of inactivation of Foxa2 in lung cancer, its downstream targets (15-PGDH) and prognostic significance; 2) To establish the induction of C/EBPbeta as a novel strategy for lung cancer treatment; 3) To evaluate the synthetic triterpenoids (CDDO and derivatives) as compounds capable of inducing C/EBPbeta and as potent therapeutic options for lung cancer. The foreseeable clinical potential of these studies are the identification of novel prognostic markers in early stage non-small cell lung cancer (Foxa2) and the sound introduction of oral compounds – currently in human phase I clinical trials (as is the case of CDDO-Me) – that can re-activate the crucial C/EBP lung differentiation pathway and halt proliferation as well as induce apoptosis in NSCLC. These studies will likely be the springboard to future clinical trials in patients with this malignancy.
Project 3: Targeting erlotinib-resistant lung cancer with rational combination treatments
Project Co-Leaders: Jeffrey Settleman, PhD (MGH) and Henning Willers, MD (MGH)
Consultants: Daniel Haber, MD, PhD (MGH) and Lecia Sequist, MD, MPH (MGH)
Lung cancer is the leading cause of cancer deaths, and is largely refractory to standard chemotherapy. Selective EGFR inhibitors (e.g., erlotinib) elicit clinical responses in 10-20% of non-small cell lung cancers (NSCLC), which correlates with activating EGFR mutations. However, there remains a large fraction of patients for which erlotinib, as monotherapy, is ineffective. EGFR is expressed in most NSCLCs, suggesting that it may still be an important therapeutic target, in conjunction with additional treatment. We propose to expand the clinical utility of erlotinib by identifying a rational combination with a second treatment to benefit an additional subset of NSCLC patients. Aim 1: To establish the efficacy of erlotinib in combination with a second treatment. By utilizing 108 NSCLC erlotinib-refractory cell lines, we will test the ability of erlotinib plus an additional treatment to produce cytostatic or cytotoxic activity. We will focus on inhibitors of the MET and IGF-1 kinases, as well as HSP90. We will also test the ability of ionizing radiation to synergize with erlotinib. Together, these studies are expected to reveal subsets of NSCLCs that are sensitive to the proposed combination therapies. Aim 2: To establish mechanisms by which combination treatment with erlotinib and a second agent inhibits cell survival. In NSCLC cell lines with synergistic response to combination treatment, we will test the hypothesis that inhibition of survival pathways that may be redundant to EGFR-derived signals produces synthetic lethality. We will also characterize radiation-induced EGFR activation in NSCLCs that are sensitive to erlotinib and radiation, and we will confirm that such EGFR activation is also seen in NSCLC patient explants. We hypothesize that cell death observed in highly sensitive cell lines resembles the previously described apoptotic response to erlotinib in cells with EGFR mutations. Aim 3: To identify biomarkers that predict sensitivity to treatment combinations. In cell lines sensitive to combination treatment, we will correlate sensitivity with: (i) recurrent gene mutations in NSCLC, (ii) comparative genome hybridization array data, and (iii) gene expression profiles. Our findings are expected to inform clinical trials for NSCLC patients with acquired erlotinib/gefitinib resistance (in development in Projects 4 and 5 of this SPORE) and ultimately lead to genotype-driven trials of novel drug combinations or molecularly targeted radiation therapy in patients whose tumors exhibit primary erlotinib resistance.
Project 4: Translational Studies of Hsp90 Inhibitors in NSCLC
Project Co-Leaders: Geoffrey Shapiro, MD, PhD (DFCI) and Kwok-Kin Wong, MD, PhD (DFCI)
Investigator: Lecia Sequist, MD, MPH (MGH)
The Hsp90 chaperone is required for the stability of multiple oncogenic kinases that drive signaling, proliferation and survival of non-small cell lung cancers (NSCLCs), including mutant EGFR, Her2, B-Raf, c-Met and cdk4. Inhibitors of Hsp90 will be studied including geldanamycins such as 17-AAG, the water-soluble derivatives IPI-504 and 17-DMAG, and STA-9090, a novel non-geldanamycin, to compare their relative potencies, to define pharmacodynamic endpoints and to conduct clinical trials in molecularly defined patient subgroups. In the first specific aim, these compounds will be studied in EGFR mutant NSCLC cells, including those expressing mutant EGFR harboring the T790M secondary mutation conferring erlotinib resistance. The ability of Hsp90 inhibitors to deplete mutant EGFR and to suppress downstream signaling of the PI3K-Akt-mTOR-p70S6K pathway will be assessed. The relative potencies of 17-DMAG and STA-9090 will be compared to 17-AAG in isogenic cell line models in vitro, and in EGFR mutant/T790M NCI-H1975 xenografts in vivo. The activity of these compounds will also be evaluated in mutant EGFR-driven models of lung adenocarcinoma. In the second specific aim, the activity of Hsp90 inhibitors will be assessed in EGFR wild-type cells driven by other Hsp90 clients. Additionally, Hsp90 inhibitor-mediated depletion of IGF-1R will be evaluated in cells expressing EGFR: IGF-1R heterodimers to determine if there is cytotoxic synergy with erlotinib. In the third specific aim, synergism of 17-AAG with other agents that disrupt chaperone function or Hsp70 induction will be explored, including inhibitors of HDAC6, the proteasome or cyclin-dependent kinase 9. In the fourth specific aim, a Phase I/II Trial of IPI-504 will be conducted; after establishment of the maximum tolerated dose (MTD), preliminary antitumor activity will be defined in NSCLC patients harboring either EGFR mutant or wild-type tumors. A Phase I trial of STA-9090 will also be performed to establish the MTD and safety profile. Hsp90 client depletion will be evaluated in tumor biopsy specimens and peripheral blood mononuclear cells. In summary, survival for advanced NSCLC remains poor. Many proteins that drive lung cancer growth depend on a chaperone called Hsp90 for their stability and function. This work will explore compounds that inhibit Hsp90 in preclinical models and clinical trials as potential treatments for lung cancer.
Projet 5: Mechanisms of acquired resistance to epidermal growth factor receptor-targeted agents
Project Co-Leaders: Pasi Jänne, MD, PhD (DFCI) and Jeffrey Engelman, MD, PhD (MGH)
Investigator: Lewis Cantley, PhD (BIDMC)
The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib are effective therapeutic agents for patients with non-small cell lung cancer (NSCLC) whose tumors harbor activating mutations in EGFR. Most, if not all, patients who initially develop a partial or complete response to gefitinib or erlotinib will eventually develop progression of their cancer while taking these therapies. The only known mechanism of resistance, a secondary mutation in EGFR itself (a substitution of methionine for threonine at position 790, EGFR T790M) has been detected in approximately 50% of patients developing resistance to gefitinib or erlotinib. This finding has spurred the clinical development of irreversible EGFR inhibitors that can inhibit an EGFR T790M to treat cancers that have become resistant to gefitinib/erlotinib. To identify of mechanisms of acquired resistance to gefitinib or erlotinib, we have generated gefitinib-resistant clones of EGFR mutant NSCLC cell lines by exposing them to increasing concentrations of gefitinib. In previous work, we identified an EGFR T790M in vitro model of resistance, thereby demonstrating that in vitro models can be used to discover resistance mechanisms observed in patients. These paired (parental and resistant clone) cell lines provide valuable preclinical models in which to systematically determine mechanisms of gefitinib resistance and their in vitro sensitivity to novel therapeutic agents. Once identified, tumor specimens from EGFR mutant patients that have developed acquired resistance to gefitinib/erlotinib will be assessed to determine if these resistance mechanisms can also be detected in patients. Furthermore, based on the findings above, novel therapeutic combinations will be evaluated in the gefitinib-resistant cell line models with differing mechanisms of resistance. These studies will serves as the basis for rationally designed clinical trials for patients with gefitinib/erlotinib resistance. These studies will be accomplished through the following specific aims: Aim 1: To discover mechanisms of acquired resistance to EGFR-targeted agents. Aim 2: To determine whether targeting resistance mechanisms in vitro using pharmacologic inhibitors or by RNA interference (RNAi) will lead to growth inhibition of resistant NSCLC cell lines Aim 3: To design and conduct clinical studies in NSCLC patients with different mechanisms of acquired resistance to gefitinib/erlotinib. Since EGFR TKIs are highly effective initial treatments for patients with EGFR mutant cancers, it will be critical to identify the how these cancers eventually become resistant. The studies in this grant proposal will help develop the future treatments for patients with different mechanisms of acquired resistance to EGFR TKIs.
