Description: Purpose: Effective therapies for KRAS -mutant colorectal cancer (CRC) are a critical unmet clinical need. Previously, we described genetically engineered mouse models (GEMM) for sporadic Kras -mutant and non-mutant CRC suitable for preclinical evaluation of experimental therapeutics. To accelerate drug discovery and validation, we sought to derive low-passage cell lines from GEMM Kras -mutant and wild-type tumors for in vitro screening and transplantation into the native colonic environment of immunocompetent mice for in vivo validation. Experimental Design: Cell lines were derived from Kras -mutant and non-mutant GEMM tumors under defined media conditions. Growth kinetics, phosphoproteomes, transcriptomes, drug sensitivity, and metabolism were examined. Cell lines were implanted in mice and monitored for in vivo tumor analysis. Results: Kras -mutant cell lines displayed increased proliferation, mitogen-activated protein kinase signaling, and phosphoinositide-3 kinase signaling. Microarray analysis identified significant overlap with human CRC-related gene signatures, including KRAS -mutant and metastatic CRC. Further analyses revealed enrichment for numerous disease-relevant biologic pathways, including glucose metabolism. Functional assessment in vitro and in vivo validated this finding and highlighted the dependence of Kras -mutant CRC on oncogenic signaling and on aerobic glycolysis. Conclusions: We have successfully characterized a novel GEMM-derived orthotopic transplant model of human KRAS -mutant CRC. This approach combines in vitro screening capability using low-passage cell lines that recapitulate human CRC and potential for rapid in vivo validation using cell line-derived tumors that develop in the colonic microenvironment of immunocompetent animals. Taken together, this platform is a clear advancement in preclinical CRC models for comprehensive drug discovery and validation efforts. Clin Cancer Res; 19(11); 2929–40. ©2013 AACR .

Description: Pyruvate dehydrogenase kinase PDK1 is a metabolic enzyme responsible for switching glucose metabolism from mitochondrial oxidation to aerobic glycolysis in cancer cells, a general hallmark of malignancy termed the Warburg effect. Herein we report the identification of JX06 as a selective covalent inhibitor of PDK1 in cells. JX06 forms a disulfide bond with the thiol group of a conserved cysteine residue (C240) based on recognition of a hydrophobic pocket adjacent to the ATP pocket of the PDK1 enzyme. Our investigations of JX06 mechanism suggested that covalent modification at C240 induced conformational changes at Arginine 286 through Van der Waals forces, thereby hindering access of ATP to its binding pocket and in turn impairing PDK1 enzymatic activity. Notably, cells with a higher dependency on glycolysis were more sensitive to PDK1 inhibition, reflecting a metabolic shift that promoted cellular oxidative stress and apoptosis. Our findings offer new mechanistic insights including how to therapeutically target PDK1 by covalently modifying the C240 residue. Cancer Res; 75(22); 4923–36. ©2015 AACR.

Description: Purpose: We investigated the incidence of concomitant epidermal growth factor receptor ( EGFR ) mutations and anaplastic lymphoma kinase ( ALK ) rearrangements in Chinese patients with non–small cell lung cancer (NSCLC), and assessed responses to EGFR tyrosine kinase inhibitors (EGFR-TKIs) and crizotinib in such tumors. Experimental Design: We screened 977 consecutive patients with NSCLC for the presence of concomitant EGFR mutations and ALK rearrangements by rapid amplification of cDNA ends-coupled PCR sequencing and FISH. Immunohistochemistry (IHC) and Western blotting were used to correlate the activation of EGFR, ALK, and downstream proteins with responses to EGFR-TKIs and crizotinib. Results: The overall frequency of concomitant EGFR mutations and ALK rearrangements was 1.3% (13/977). EGFR/ALK co-alterations were found in 3.9% (13/336) EGFR- mutant and 18.6% (13/70) ALK- rearranged patients. Ten tumors were treated with first-line EGFR-TKIs, with a response rate of 80% (8/10). Two tumors with high phospho-ALK levels and low phospho-EGFR levels achieved stable and progressive disease, respectively. Median progression-free survival was 11.2 months. Coexpression of mutant EGFR and ALK fusion proteins in the same tumor cell populations was detected by IHC. Two cases with high phospho-ALK levels treated with crizotinib achieved partial responses; two cases with low phospho-ALK levels had progressive or stable disease. Conclusion: ALK rearrangements and EGFR mutations could coexist in a small subgroup of NSCLC. Advanced pulmonary adenocarcinomas with such co-alterations could have diverse responses to EGFR-TKIs and crizotinib. Relative phospho-ALK and phospho-EGFR levels could predict the efficacy of EGFR-TKI and crizotinib. Clin Cancer Res; 20(5); 1383–92. ©2014 AACR .

Description: Purpose: MET amplification, responsible for 20% of acquired resistance to EGFR tyrosine kinase inhibitor (TKI) in patients with advanced non–small cell lung cancer (NSCLC), presents an attractive target. Numerous studies have conferred susceptibility of MET mutations and focal amplification to targeted MET-TKIs. However, the mechanism underlying MET-TKIs–induced resistance remains elusive. Experimental Design: We conducted a cohort of 12 patients with advanced NSCLC who developed resistance to a combinatorial therapy consisting of gefitinib and a type I MET-TKI. We performed capture-based targeted ultra-deep sequencing on serial tumor biopsies and plasmas ctDNA samples to detect and quantify genetic alterations. Results: We identified 2 newly acquired MET mutations, Y1248H and D1246N, in 2 patients and further confirmed their resistance against type I MET-TKIs in silco, in vitro , and in vivo . Interestingly, NIH3T3 cells harboring either mutation exhibited responses to type II MET-TKIs, suggesting sequential use of MET-TKIs may offer a more durable response. In addition, we also discovered that EGFR amplification may act as an alternative MET-TKI resistance mechanism. Conclusions: Our study provides insight into the diversity of mechanisms underlying MET-TKI–induced resistance and highlights the potential of sequential use of MET-TKIs. Clin Cancer Res; 23(16); 4929–37. ©2017 AACR .

Description: Purpose: Although clinical studies have shown promise for targeting programmed cell death protein-1 (PD-1) and ligand (PD-L1) signaling in non–small cell lung cancer (NSCLC), the factors that predict which subtype patients will be responsive to checkpoint blockade are not fully understood. Experimental Design: We performed an integrated analysis on the multiple-dimensional data types including genomic, transcriptomic, proteomic, and clinical data from cohorts of lung adenocarcinoma public (discovery set) and internal (validation set) database and immunotherapeutic patients. Gene set enrichment analysis (GSEA) was used to determine potentially relevant gene expression signatures between specific subgroups. Results: We observed that TP53 mutation significantly increased expression of immune checkpoints and activated T-effector and interferon- signature. More importantly, the TP53/KRAS comutated subgroup manifested exclusive increased expression of PD-L1 and a highest proportion of PD-L1 + /CD8A + . Meanwhile, TP53- or KRAS -mutated tumors showed prominently increased mutation burden and specifically enriched in the transversion-high (TH) cohort. Further analysis focused on the potential molecular mechanism revealed that TP53 or KRAS mutation altered a group of genes involved in cell-cycle regulating, DNA replication and damage repair. Finally, immunotherapeutic analysis from public clinical trial and prospective observation in our center were further confirmed that TP53 or KRAS mutation patients, especially those with co-occurring TP53/KRAS mutations, showed remarkable clinical benefit to PD-1 inhibitors. Conclusions: This work provides evidence that TP53 and KRAS mutation in lung adenocarcinoma may be served as a pair of potential predictive factors in guiding anti–PD-1/PD-L1 immunotherapy. Clin Cancer Res; 23(12); 3012–24. ©2016 AACR .

Description: Purpose: Tumor heterogeneity may represent a barrier to preoperative genomic characterization by needle biopsy in clear cell renal cell carcinoma (ccRCC). The extent of heterogeneity in small renal tumors remains unknown. Therefore, we set out to evaluate heterogeneity in resected large and small renal tumors. Experimental Design: We conducted a study from 2013 to 2016 that evaluated 47 consecutive ccRCC tumors resected during radical or partial nephrectomy. Cases were designated as small (〈4 cm) and large (〉7 cm) tumors. Each tumor had three regions sampled. Copy-number variation (CNV) was assessed and gene expression analysis was performed to characterize the clear-cell A and B (ccA/ccB) profile and the cell-cycle progression (CCP) score. Genomic heterogeneity between three regions was evaluated using CNV subclonal events, regional expression profiles, and correlation between gene expression. Results: Twenty-three small and 24 large tumors were analyzed. Total CNVs and subclonal CNVs events were less frequent in small tumors ( P 〈 0.001). Significant gene expression heterogeneity was observed for both CCP scores and ccA/ccB classifications. Larger tumors had more variance in CCP scores ( P = 0.026). The distribution of ccA/ccB differed between small and large tumors with mixed ccA/ccB tumors occurring more frequently in the larger tumors ( P = 0.024). Analysis of five mixed tumors (with both ccA/ccB regions) demonstrated the more aggressive ccB phenotype had greater CNV events ( P = 0.014). Conclusions: Small renal tumors have much less genomic complexity and fewer subclonal events. Pretreatment genomic characterization with single-needle biopsy in small tumors may be useful to assess biologic potential and may influence therapy. Clin Cancer Res; 24(17); 4137–44. ©2018 AACR .