Non-small cell lung cancer (NSCLC)

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-associated deaths worldwide. Given the limited effectiveness of current treatments, there is a significant need to identify new driver genes that participate in lung cancer pathogenesis. Dr. O’Donnell and her group identified PROTOCADHERIN 7 (PCDH7) in a functional screen for genes that promote transformation of human bronchial epithelial cells (HBECs). This is of interest because PCDH7 encodes a poorly characterized cell surface receptor that is frequently overexpressed in NSCLC and high expression strongly associates with poor survival of NSCLC patients. Moreover, the presence of PCDH7 on the cell surface highlights the potential of this molecule as a novel target for future therapeutics.

They demonstrated that 1) enforced expression of PCDH7 is sufficient to promote transformation of HBECs, 2) PCDH7 cooperates with oncogenic KRAS to promote tumorigenesis, and 3) PCDH7 potently enhances KRAS-mediated activation of the ERK1/2 pathway. They will elucidate the role of this lung cancer driver by testing the following central hypothesis: Overexpression of PCDH7 initiates a signal transduction cascade that potentiates KRAS-induced MAPK-ERK signaling to promote lung tumorigenesis. In Aim 1, they will correlate PCDH7 immunoexpression with clinical features of resected NSCLCs. In Aim 2, they will elucidate the mechanisms through which PCDH7 potentiates MAPK signaling and tumorigenesis. In Aim 3, they will develop and test the therapeutic efficacy of PCDH7 blocking antibodies in patient-derived xenografts.

These experiments will yield insights into the mechanisms of PCDH7-mediated transformation and reveal new opportunities to pursue this cell-surface receptor as a therapeutic target in NSCLC.

KRAS mutations activate signaling from downstream effector proteins and are though to be required for tumor formation. Exactly how effector signaling is activated, however, is not fully understood. In addition, whether tumors harboring KRAS mutations depend on this oncogene for growth is unclear.

Dr. Lito and his group will dissect the phenotype of KRAS-mutant lung cancer by using a novel allosteric inhibitor that selectively targets KRAS G12C. They will first utilize biochemical assays in order to determine the mechanism of action of this inhibitor. An emphasis will be placed on evaluating how feedback pathways modulate this process, since this is likely to identify factors that may be used as biomarkers of response to treatment.

They will then determine which effector pathways drive the phenotype of KRAS G12C mutant lung cancer, and whether these exhibit adaptation (or reactivation) over time. If so, they will next explore combination-based interventions in order to establish the most effective antiproliferative strategy.

Finally, they will utilize novel patient-derived xenograft and cell line models, established from patients with lung cancer treated at MSKCC, in order to determine if KRAS G12C mutant lung cancers depend on this oncoprotein for growth. These models will also be used to test the most effective combination strategies determined above, as well as to test the potential benefit of intermittent administration schemes designed to best target tumor adaptation to this novel class of inhibitors.

The grand objective of this project is to establish a mutant KRAS-directed therapy for patients with lung cancer. 

Circulating tumor cells (CTCs) are cancer cells that break away from either the primary tumor or metastatic sites. Increasingly, CTCs have been used as a readily accessible source of tumor cells (“liquid biopsy”). However, shortcomings in current CTC technologies limit downstream analyses to assessment of a selected set of nucleic acid markers. Genome and transcriptome-wide analyses of CTCs have been hampered by the low purity of CTC isolates. The complex and protracted nature of CTC capture protocols further impedes analysis.

Dr. Kulkarni and his group have developed a CTC capture technology known as Vortex Chip, which allows for rapid isolation of highly purified CTCs. In addition to standard immunofluorescence, they have generated proof-of-principle evidence that their capture technology allows for analysis of genetic material. Moreover, because the Vortex Chip isolates CTCs based on their size, their chip does not require antibody-based capture that can potentially bias isolation of CTC subpopulations. Serial CTC analyses performed in the context of treatment changes can characterize the mutational landscape of tumors as they evolve in response to therapy and thereby identify molecular predictors and drivers of treatment resistance and sensitivity to novel anti-tumor therapies.

Their project has two goals: 1) validate use of CTCs as biomarker in lung cancer and 2) explore use of CTC analysis to obtain genetic information about the tumor. They hypothesize that the unique microfluidic characteristics of lung CTCs will drive rapid isolation of pure CTC populations for analysis to characterize heterogeneity and profile therapeutic responsiveness.