Immune-related adverse events are associated with improved response, progression-free survival, and overall survival for patients with head and neck cancer receiving immune checkpoint inhibitors.

BACKGROUND: The authors hypothesized that patients developing immune-related adverse events (irAEs) while receiving immune checkpoint inhibition (ICI) for recurrent/metastatic head and neck cancer (HNC) would have improved oncologic outcomes. METHODS: Patients with recurrent/metastatic HNC received ICI at 2 centers. Univariate and multivariate logistic regression, Kaplan-Meier methods, and Cox proportional hazards regression were used to associate the irAE status with the overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) in cohort 1 (n = 108). These outcomes were also analyzed in an independent cohort of patients receiving ICI (cohort 2; 47 evaluable for irAEs). RESULTS: The median follow-up was 8.4 months for patients treated in cohort 1. Sixty irAEs occurred in 49 of 108 patients with 5 grade 3 or higher irAEs (10.2%). ORR was higher for irAE+ patients (30.6%) in comparison with irAE- patients (12.3%; P = .02). The median PFS was 6.9 months for irAE+ patients and 2.1 months for irAE- patients (P = .0004), and the median OS was 12.5 and 6.8 months, respectively (P = .007). Experiencing 1 or more irAEs remained associated with ORR (P = .03), PFS (P = .003), and OS (P = .004) in multivariate analyses. The association between development of irAEs and prolonged OS persisted in a 22-week landmark analysis (P = .049). The association between development of irAEs and favorable outcomes was verified in cohort 2. CONCLUSIONS: The development of irAEs was strongly associated with an ICI benefit, including overall response, PFS, and OS, in 2 separate cohorts of patients with recurrent/metastatic HNC.

A pan-cancer organoid platform for precision medicine.

Patient-derived tumor organoids (TOs) are emerging as high-fidelity models to study cancer biology and develop novel precision medicine therapeutics. However, utilizing TOs for systems-biology-based approaches has been limited by a lack of scalable and reproducible methods to develop and profile these models. We describe a robust pan-cancer TO platform with chemically defined media optimized on cultures acquired from over 1,000 patients. Crucially, we demonstrate tumor genetic and transcriptomic concordance utilizing this approach and further optimize defined minimal media for organoid initiation and propagation. Additionally, we demonstrate a neural-network-based high-throughput approach for label-free, light-microscopy-based drug assays capable of predicting patient-specific heterogeneity in drug responses with applicability across solid cancers. The pan-cancer platform, molecular data, and neural-network-based drug assay serve as resources to accelerate the broad implementation of organoid models in precision medicine research and personalized therapeutic profiling programs.

Effects of selected deubiquitinating enzyme inhibitors on the proliferation and motility of lung cancer and mesothelioma cell lines.

The post­translational modification of proteins by ubiquitinating enzymes plays a central role in a number of cellular functions, such as cell proteolysis, DNA repair, and cell signaling and communication. Deubiquitinating enzymes (DUBs) disassemble ubiquitin chains and remove ubiquitin moieties from proteins. Targeting DUBs in cancer models has revealed an important role for these enzymes in tumorigenesis, and they therefore have emerged as attractive therapeutic targets. In the present study, the effects of three DUB inhibitors, PR­619, RA­9 and LDN­91946, on a non­small cell lung cancer cell line (A549) and a mesothelioma cell line (H2373) were investigated. PR­619 significantly inhibited cell adhesion and the proliferation of both cell lines. RA­9 exerted an inhibitory effect on the adhesion and proliferation of H2373 cells, whereas it had no effect on A549 cells. Notably, however, while PR­619 attenuated the proliferation of both cell lines, it exerted an opposite effect on cell motility; in the case of A549 cells, there was a significant increase in cell motility, while for the H2373 cells, there was a significant decrease. Furthermore, protein phosphorylation kinetic analyses revealed that the effects were cell line­specific. In H2373 cells, the phosphorylation of only one peptide corresponding to the P85A protein was significantly affected, and while LDN­91946 treatment increased phosphorylation, treatment with RA­9 or PR­619 decreased its phosphorylation compared to the DMSO control. By contrast, in the case of A549 cells, the phosphorylation of 21 peptides was significantly affected by the same compounds. In light of the potential for the negative side­effects of DUB inhibition, such as increased cancer cell motility, the data presented herein underscore the dire need for the development of specific DUB inhibitors and to elucidate the individual role of DUB family members in cancer biology before they can be specifically pharmacologically targeted.

EPHA2 mutations with oncogenic characteristics in squamous cell lung cancer and malignant pleural mesothelioma.

Squamous cell carcinoma (SCC) and malignant pleural mesothelioma (MPM) are thoracic malignancies with very poor prognosis and limited treatment options. It is an established fact that most of the solid tumors have overexpression of EPHA2 receptor tyrosine kinase. EPHA2 is known to exhibit opposing roles towards cancer progression. It functions in inhibiting cancer survival and migration via a ligand and tyrosine kinase dependent signaling (Y772). Whereas it is known to promote tumor progression and cell migration through a ligand-independent signaling (S897). We analyzed the expression profile and mutational status of the ephrin receptor A2 (EPHA2) in SCC and MPM cell lines and primary patient specimens. The EPHA2 receptor was found to be either overexpressed, mutated or amplified in SCC and MPM. In particular, the EPHA2 mutants A859D and T647M were interesting to explore, A859D Y772 dead mutant exhibited lower levels of phosphorylation at Y772 compared to T647M mutant. Molecular Dynamics simulations studies suggested that differential changes in conformation might form the structural basis for differences in the level of EPHA2 activation. Consequently, A859D mutant cells exhibited increased proliferation as well as cell migration compared to controls and T647M mutant. Kinomics analysis demonstrated that the STAT3 and PDGF pathways were upregulated whereas signaling through CBL was suppressed. Considered together, the present work has uncovered the oncogenic characteristics of EPHA2 mutations in SSC and MPM reinstating the dynamics of different roles of EPHA2 in cancer. This study also suggests that a combination of doxazosin and other EPHA2 inhibitors directed to inhibit the pertinent signaling components may be a novel therapeutic strategy for MPM and Non-small cell lung cancer patients who have either EPHA2 or CBL alterations.

Inhibiting crosstalk between MET signaling and mitochondrial dynamics and morphology: a novel therapeutic approach for lung cancer and mesothelioma.

The receptor tyrosine kinase MET is frequently involved in malignant transformation and inhibiting its activity in MET-dependent cancers is associated with improved clinical outcomes. Emerging evidence also suggests that mitochondria play an essential role in tumorigenesis and Dynamin Related Protein (DRP1), a key component of the mitochondrial fission machinery, has emerged as an attractive therapeutic target. Here, we report that inhibiting MET activity with the tyrosine kinase inhibitor MGCD516 attenuates viability, migration, and invasion of non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MPM) cell lines in vitro, and significantly retards tumor growth in vivo. Interestingly, MGCD516 treatment also results in altered mitochondrial morphology in these cell lines. Furthermore, inhibiting MET pharmacologically or knocking down its expression using siRNA, decreases DRP1 activity alluding to possible crosstalk between them in these two cancers. Consistently, a combination of MGCD516 and mdivi-1, a quinazolinone reported to inhibit mitochondrial fission, is more effective in attenuating proliferation of NSCLC and MPM cell lines than either drug alone. Considered together, the present study has uncovered a novel mechanism underlying mitochondrial regulation by MET that involves crosstalk with DRP1, and suggests that a combination therapy targeting both MET and DRP1 could be a novel strategy for NSCLC and MPM.

Differential responsiveness of MET inhibition in non-small-cell lung cancer with altered CBL.

Casitas B-lineage lymphoma (CBL) is an E3 ubiquitin ligase and a molecule of adaptor that we have shown is important for non-small-cell lung cancer (NSCLC). We investigated if MET is a target of CBL and if enhanced in CBL-altered NSCLC. We showed that CBL wildtype cells have lower MET expression than CBL mutant cells. Ubiquitination of MET was also decreased in CBL mutant cells compared to wildtype cells. Mutant cells were also more sensitive to MET inhibitor SU11274 than wild-type cells. sh-RNA-mediated knockdown of CBL enhanced cell motility and colony formation in NSCLC cells, and these activities were inhibited by SU11274. Assessment of the phospho-kinome showed decreased phosphorylation of pathways involving MET, paxillin, EPHA2, and VEGFR. When CBL was knocked down in the mutant cell line H1975 (erlotinib-resistant), it became sensitive to MET inhibition. Our findings suggest that CBL status is a potential positive indicator for MET-targeted therapeutics in NSCLC.

Expression and mutational analysis of c-CBL and its relationship to the MET receptor in head and neck squamous cell carcinoma.

MET is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) and degraded by c-CBL E3-ubiquitin ligase. We investigated genetic variations of c-CBL in HNSCC and the relationship between c-CBL and MET expression. High MET, low c-CBL expression was detected in 10 cell lines and 73 tumor tissues. Two novel mutations (L254S, L281F), and the single nucleotide polymorphism (SNP) P782L were identified from archival tumor tissues. 27.3% of loss of heterozygosity was found at CBL locus. Ectopic expression of wild-type c-CBL in SCC-35 cells downregulated MET expression and decreased cell viability. These results suggest MET overexpression is related to altered c-CBL expression, which may influence tumorigenesis.

The Chicago Thoracic Oncology Database Consortium: A Multisite Database Initiative.

OBJECTIVE: An increasing amount of clinical data is available to biomedical researchers, but specifically designed database and informatics infrastructures are needed to handle this data effectively. Multiple research groups should be able to pool and share this data in an efficient manner. The Chicago Thoracic Oncology Database Consortium (CTODC) was created to standardize data collection and facilitate the pooling and sharing of data at institutions throughout Chicago and across the world. We assessed the CTODC by conducting a proof of principle investigation on lung cancer patients who took erlotinib. This study does not look into epidermal growth factor receptor (EGFR) mutations and tyrosine kinase inhibitors, but rather it discusses the development and utilization of the database involved. METHODS:  We have implemented the Thoracic Oncology Program Database Project (TOPDP) Microsoft Access, the Thoracic Oncology Research Program (TORP) Velos, and the TORP REDCap databases for translational research efforts. Standard operating procedures (SOPs) were created to document the construction and proper utilization of these databases. These SOPs have been made available freely to other institutions that have implemented their own databases patterned on these SOPs. RESULTS: A cohort of 373 lung cancer patients who took erlotinib was identified. The EGFR mutation statuses of patients were analyzed. Out of the 70 patients that were tested, 55 had mutations while 15 did not. In terms of overall survival and duration of treatment, the cohort demonstrated that EGFR-mutated patients had a longer duration of erlotinib treatment and longer overall survival compared to their EGFR wild-type counterparts who received erlotinib. DISCUSSION: The investigation successfully yielded data from all institutions of the CTODC. While the investigation identified challenges, such as the difficulty of data transfer and potential duplication of patient data, these issues can be resolved with greater cross-communication between institutions of the consortium. CONCLUSION: The investigation described herein demonstrates the successful data collection from multiple institutions in the context of a collaborative effort. The data presented here can be utilized as the basis for further collaborative efforts and/or development of larger and more streamlined databases within the consortium.

Comprehensive genetic testing identifies targetable genomic alterations in most patients with non-small cell lung cancer, specifically adenocarcinoma, single institute investigation.

This study reviews extensive genetic analysis in advanced non-small cell lung cancer (NSCLC) patients in order to: describe how targetable mutation genes interrelate with the genes identified as variants of unknown significance; assess the percentage of patients with a potentially targetable genetic alterations; evaluate the percentage of patients who had concurrent alterations, previously considered to be mutually exclusive; and characterize the molecular subset of KRAS. Thoracic Oncology Research Program Databases at the University of Chicago provided patient demographics, pathology, and results of genetic testing. 364 patients including 289 adenocarcinoma underwent genotype testing by various platforms such as FoundationOne, Caris Molecular Intelligence, and Response Genetics Inc. For the entire adenocarcinoma cohort, 25% of patients were African Americans; 90% of KRAS mutations were detected in smokers, including current and former smokers; 46% of EGFR and 61% of ALK alterations were detected in never smokers. 99.4% of patients, whose samples were analyzed by next-generation sequencing (NGS), had genetic alterations identified with an average of 10.8 alterations/tumor throughout different tumor subtypes. However, mutations were not mutually exclusive. NGS in this study identified potentially targetable genetic alterations in the majority of patients tested, detected concurrent alterations and provided information on variants of unknown significance at this time but potentially targetable in the future.

Novel EPHB4 Receptor Tyrosine Kinase Mutations and Kinomic Pathway Analysis in Lung Cancer.

Lung cancer outcomes remain poor despite the identification of several potential therapeutic targets. The EPHB4 receptor tyrosine kinase (RTK) has recently emerged as an oncogenic factor in many cancers, including lung cancer. Mutations of EPHB4 in lung cancers have previously been identified, though their significance remains unknown. Here, we report the identification of novel EPHB4 mutations that lead to putative structural alterations as well as increased cellular proliferation and motility. We also conducted a bioinformatic analysis of these mutations to demonstrate that they are mutually exclusive from other common RTK variants in lung cancer, that they correspond to analogous sites of other RTKs' variations in cancers, and that they are predicted to be oncogenic based on biochemical, evolutionary, and domain-function constraints. Finally, we show that EPHB4 mutations can induce broad changes in the kinome signature of lung cancer cells. Taken together, these data illuminate the role of EPHB4 in lung cancer and further identify EPHB4 as a potentially important therapeutic target.

The EphB4 receptor tyrosine kinase promotes lung cancer growth: a potential novel therapeutic target.

Despite progress in locoregional and systemic therapies, patient survival from lung cancer remains a challenge. Receptor tyrosine kinases are frequently implicated in lung cancer pathogenesis, and some tyrosine kinase inhibition strategies have been effective clinically. The EphB4 receptor tyrosine kinase has recently emerged as a potential target in several other cancers. We sought to systematically study the role of EphB4 in lung cancer. Here, we demonstrate that EphB4 is overexpressed 3-fold in lung tumors compared to paired normal tissues and frequently exhibits gene copy number increases in lung cancer. We also show that overexpression of EphB4 promotes cellular proliferation, colony formation, and motility, while EphB4 inhibition reduces cellular viability in vitro, halts the growth of established tumors in mouse xenograft models when used as a single-target strategy, and causes near-complete regression of established tumors when used in combination with paclitaxel. Taken together, these data suggest an important role for EphB4 as a potential novel therapeutic target in lung cancer. Clinical trials investigating the efficacy of anti-EphB4 therapies as well as combination therapy involving EphB4 inhibition may be warranted.

Lack of association of C-Met-N375S sequence variant with lung cancer susceptibility and prognosis.

BACKGROUND: Previously, we identified a sequence variant (N375S) of c-Met gene, however, its association with lung cancer risk and prognosis remain undefined. PATIENTS AND METHODS: We investigated the genotype distribution of the c-Met-N375S sequence variant in 206 lung cancer patients and 207 non-cancer controls in the Taiwanese population by DNA sequencing. RESULTS: Lung cancer patients with variant A/G and G/G genotypes showed 1.08-fold increased cancer risk when compared to patients with the wild-type A/A genotype (95% CI, 0.60-1.91). There were no significant differences in postoperative survival between c-Met-N375S and wild-type patients. In the cell model, the c-Met-N375S cells showed a decrease in cell death upon treatment with MET inhibitor SU11274 compared to wild-type cells. CONCLUSION: Our data suggest that the c-Met-N375S sequence variant may not play a significant role in cancer susceptibility and the prognosis of lung cancer patients. The correlation with chemoresponse of c-Met-N375S is worth further investigation in patients receiving MET therapy.

Paxillin mutations affect focal adhesions and lead to altered mitochondrial dynamics: relevance to lung cancer.

Cytoskeletal and focal adhesion abnormalities are observed in several types of cancer, including lung cancer. We have previously reported that paxillin (PXN) was mutated, amplified, and overexpressed in a significant number of lung cancer patient samples, that PXN protein was upregulated in more advanced stages of lung cancer compared with lower stages, and that the PXN gene was also amplified in some pre-neoplastic lung lesions. Among the mutations investigated, we previously found that PXN variant A127T in lung cancer cells enhanced cell proliferation and focal adhesion formation and colocalized with the anti-apoptotic protein B Cell Lymphoma 2 (BCL-2), which is known to localize to the mitochondria, among other sites. To further explore the effects of activating mutations of PXN on mitochondrial function, we cloned and expressed wild-type PXN and variants containing the most commonly occurring PXN mutations (P46S, P52L, G105D, A127T, P233L, T255I, D399N, E423K, P487L, and K506R) in a GFP-tagged vector using HEK-293 human embryonic kidney cells. Utilizing live-cell imaging to systematically study the effects of wild-type PXN vs. mutants, we created a model that recapitulates the salient features of the measured dynamics and conclude that compared with wild-type, some mutant clones confer enhanced focal adhesion and lamellipodia formation (A127T, P233L, and P487L) and some confer increased association with BCL-2, Dynamin-related Protein-1 (DRP-1), and Mitofusion-2 (MFN-2) proteins (P233L and D399N). Further, PXN mutants, through their interactions with BCL-2 and DRP-1, could regulate cisplatin drug resistance in human lung cancer cells. The data reported herein suggest that mutant PXN variants play a prominent role in mitochondrial dynamics with direct implications on lung cancer progression and hence, deserve further exploration as therapeutic targets.

Differential expression of RON in small and non-small cell lung cancers.

RON is a MET related receptor tyrosine kinase (RTK) and its natural ligand is macrophage stimulating protein (MSP). RON plays a very important role in the regulation of inflammation. Several studies have previously reported overexpression of RON in a variety of cancers including lung and identified numerous RON alternate splice forms that very likely contribute to tumor growth and metastasis. Here, we have analyzed the expression of total RON protein as well as its kinase-active form (phospho-RON) in 175 archival lung tumor FFPE (formalin fixed paraffin embedded) samples that included non-small-cell lung cancer (NSCLC) and small cell lung cancer (SCLC), and their metastatic forms. The frequency and intensity of RON protein expression was much higher in lung tumors of neuroendocrine origin such as SCLC and in secondary tumors that metastasized to brain. In addition, the majority of the expressed RON protein was phospho-RON. We also identified 62, and 30 kDa isoforms of RON (GenBank accession numbers are JN689381 and JN689382) using RNA isolated from pooled lung cancer cell lines and RT-PCR. A majority of the NSCLC cell lines expressed a 150 kDa band that corresponded to the RON ß chain and 120 kDa band in the panel of SCLC cell lines tested. RON was expressed on the cell surface in NSCLC cell lines. Finally, knock down of RON expression resulted in a significant loss in viability as well as motility in lung cancer cells suggesting that RON is a potential therapeutic target.

An E3 ubiquitin ligase: c-Cbl: a new therapeutic target of lung cancer.

BACKGROUND: Casitas B-lineage lymphoma (Cbl) is an E3 ubiquitin ligase of many tyrosine kinase receptors. The authors previously detected c-Cbl mutation and low protein expression in non-small cell lung cancer (NSCLC). Therefore, it was hypothesized that overexpression of wild-type c-Cbl (c-Cbl WT) exhibits tumor growth inhibition. METHODS: Wound healing and transwell assays were conducted to examine cell motility after c-Cbl WT transfection in NSCLC cell lines. The cell cycle was investigated by flow cytometry. A549 and H1299-Luc c-Cbl WT-transfected xenografts and experimental metastasis models were performed to investigate tumor growth and metastasis inhibition in vivo. RESULTS: Wound healing and transwell assays demonstrated inhibition of migration in the A549 and H226br cells 4 to 24 hours after transfection. Ectopic c-Cbl WT expression was found to reduce cell proliferation at 48 hours in A549 cells. It is important to note that A549 and H1299-Luc cells with ectopic c-Cbl WT expression demonstrated inhibition of tumor growth in vivo. A549 cells overexpressing c-Cbl WT inhibited tumor metastasis in animal models. CONCLUSIONS: To the best of the authors' knowledge, the current study is the first to demonstrate that c-Cbl WT protein overexpression inhibits tumor metastasis and tumor growth in lung cancer xenograft models. These results provide evidence that ectopic expression of c-Cbl WT protein can be potentially applied as targeted therapy for the treatment of lung cancer.

A novel histone deacetylase inhibitor exhibits antitumor activity via apoptosis induction, F-actin disruption and gene acetylation in lung cancer.

BACKGROUND: Lung cancer is the leading cause of cancer mortality worldwide, yet the therapeutic strategy for advanced non-small cell lung cancer (NSCLC) is limitedly effective. In addition, validated histone deacetylase (HDAC) inhibitors for the treatment of solid tumors remain to be developed. Here, we propose a novel HDAC inhibitor, OSU-HDAC-44, as a chemotherapeutic drug for NSCLC. METHODOLOGY/PRINCIPAL FINDINGS: The cytotoxicity effect of OSU-HDAC-44 was examined in three human NSCLC cell lines including A549 (p53 wild-type), H1299 (p53 null), and CL1-1 (p53 mutant). The antiproliferative mechanisms of OSU-HDAC-44 were investigated by flow cytometric cell cycle analysis, apoptosis assays and genome-wide chromatin-immunoprecipitation-on-chip (ChIP-on-chip) analysis. Mice with established A549 tumor xenograft were treated with OSU-HDAC-44 or vehicle control and were used to evaluate effects on tumor growth, cytokinesis inhibition and apoptosis. OSU-HDAC-44 was a pan-HDAC inhibitor and exhibits 3-4 times more effectiveness than suberoylanilide hydroxamic acid (SAHA) in suppressing cell viability in various NSCLC cell lines. Upon OSU-HDAC-44 treatment, cytokinesis was inhibited and subsequently led to mitochondria-mediated apoptosis. The cytokinesis inhibition resulted from OSU-HDAC-44-mediated degradation of mitosis and cytokinesis regulators Auroroa B and survivin. The deregulation of F-actin dynamics induced by OSU-HDAC-44 was associated with reduction in RhoA activity resulting from srGAP1 induction. ChIP-on-chip analysis revealed that OSU-HDAC-44 induced chromatin loosening and facilitated transcription of genes involved in crucial signaling pathways such as apoptosis, axon guidance and protein ubiquitination. Finally, OSU-HDAC-44 efficiently inhibited A549 xenograft tumor growth and induced acetylation of histone and non-histone proteins and apoptosis in vivo. CONCLUSIONS/SIGNIFICANCE: OSU-HDAC-44 significantly suppresses tumor growth via induction of cytokinesis defect and intrinsic apoptosis in preclinical models of NSCLC. Our data provide compelling evidence that OSU-HDAC-44 is a potent HDAC targeted inhibitor and can be tested for NSCLC chemotherapy.

CBL is frequently altered in lung cancers: its relationship to mutations in MET and EGFR tyrosine kinases.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a heterogeneous group of disorders with a number of genetic and proteomic alterations. c-CBL is an E3 ubiquitin ligase and adaptor molecule important in normal homeostasis and cancer. We determined the genetic variations of c-CBL, relationship to receptor tyrosine kinases (EGFR and MET), and functionality in NSCLC. METHODS AND FINDINGS: Using archival formalin-fixed paraffin embedded (FFPE) extracted genomic DNA, we show that c-CBL mutations occur in somatic fashion for lung cancers. c-CBL mutations were not mutually exclusive of MET or EGFR mutations; however they were independent of p53 and KRAS mutations. In normal/tumor pairwise analysis, there was significant loss of heterozygosity (LOH) for the c-CBL locus (22%, n = 8/37) and none of these samples revealed any mutation in the remaining copy of c-CBL. The c-CBL LOH also positively correlated with EGFR and MET mutations observed in the same samples. Using select c-CBL somatic mutations such as S80N/H94Y, Q249E and W802* (obtained from Caucasian, Taiwanese and African-American samples, respectively) transfected in NSCLC cell lines, there was increased cell viability and cell motility. CONCLUSIONS: Taking the overall mutation rate of c-CBL to be a combination as somatic missense mutation and LOH, it is clear that c-CBL is highly mutated in lung cancers and may play an essential role in lung tumorigenesis and metastasis.

Novel 2-step synthetic indole compound 1,1,3-tri(3-indolyl)cyclohexane inhibits cancer cell growth in lung cancer cells and xenograft models.

BACKGROUND: The clinical responses to chemotherapy in lung cancer patients are unsatisfactory. Thus, the development of more effective anticancer drugs for lung cancer is urgently needed. METHODS: A 2-step novel synthetic compound, referred to as 1,1,3-tri(3-indolyl)cyclohexane (3-indole), was generated in high purity and yield. 3-Indole was tested for its biologic activity in A549, H1299, H1435, CL1-1, and H1437 lung cancer cells. Animal studies were also performed. RESULTS: The data indicate that 3-indole induced apoptosis in various lung cancer cells. Increased cytochrome-c release from mitochondria to cytosol, decreased expression of antiapoptotic Bcl-2, and increased expression of proapoptotic Bax were observed. In addition, 3-indole stimulated caspases-3, -9, and to a lesser extent caspase-8 activities in cancer cells, suggesting that the intrinsic mitochondria pathway was the potential mechanism involved in 3-indole-induced apoptosis. 3-Indole-induced a concentration-dependent mitochondrial membrane potential dissipation and an increase in reactive oxygen species (ROS) production. Activation of c-Jun N-terminal kinase (JNK) and triggering of DNA damage were also apparent. Note that 3-indole-induced JNK activation and DNA damage can be partially suppressed by an ROS inhibitor. Apoptosis induced by 3-indole could be abrogated by ROS or JNK inhibitors, suggesting the importance of ROS and JNK stress-related pathways in 3-indole-induced apoptosis. Moreover, 3-indole showed in vivo antitumor activities against human xenografts in murine models. CONCLUSIONS: On the basis of its potent anticancer activity in cell and animal models, the data suggest that this 2-step synthetic 3-indole compound of high purity and yield is a potential candidate to be tested as a lead pharmaceutical compound for cancer treatment.

Cytotoxicity and proteomics analyses of OSU03013 in lung cancer.

PURPOSE: Most lung cancer patients have some resistance to and suffer from side effects of conventional chemotherapy. Thus, identification of a novel anticancer drug with better target selectivity for lung cancer treatment is urgently needed. EXPERIMENTAL DESIGN: In order to investigate whether OSU03013, a derivative of celecoxib, can be a potential drug for lung cancer treatment, we examined its cytotoxicity mechanisms by flow cytometry and phosphatidylserine staining in A549, CL1-1, and H1435 lung cancer cell lines, which are resistant to the conventional drug, cisplatin. In addition, we identified the affected proteins by proteomics and confirmed the selected proteins by Western blot analysis. We examined the interaction between OSU03013 and potential target protein by molecular modeling. RESULTS: Our results indicated that OSU03013 had low-dose (1 approximately 4 microM) cytotoxicity in all lung cancer cell lines tested 48 hours posttreatment. OSU03013 caused cell cycle G1 phase arrest and showed phosphatidylserine early apoptosis via endoplasmic reticulum stress. Several proteins such as heat shock protein 27, 70, and 90, CDC2, alpha-tubulin, annexin A3, cAMP-dependent protein kinase, glycogen synthase kinase 3-beta, and beta-catenin were identified by proteomics and confirmed by Western blot. In addition, molecular modeling showed that OSU03013 competes with ATP to bind to cAMP-dependent protein kinase. CONCLUSIONS: We identified for the first time that OSU03013 inhibits cAMP-dependent protein kinase activity and causes dephosphorylation of glycogen synthase kinase 3-beta leading to beta-catenin degradation, which is often overexpressed in lung cancer. Our molecular and proteomic results show the potential of OSU03013 as an anticancer drug for lung cancer.