Evaluating Osteoarthritis Management Programs: outcome domain recommendations from the OARSI Joint Effort Initiative

OBJECTIVE

To develop sets of core and optional recommended domains for describing and evaluating Osteoarthritis Management Programs (OAMPs), with a focus on hip and knee Osteoarthritis (OA).

DESIGN

We conducted a 3-round modified Delphi survey involving an international group of researchers, health professionals, health administrators and people with OA. In Round 1, participants ranked the importance of 75 outcome and descriptive domains in five categories: patient impacts, implementation outcomes, and characteristics of the OAMP and its participants and clinicians. Domains ranked as "important" or "essential" by ≥80% of participants were retained, and participants could suggest additional domains. In Round 2, participants rated their level of agreement that each domain was essential for evaluating OAMPs: 0 = strongly disagree to 10 = strongly agree. A domain was retained if ≥80% rated it ≥6. In Round 3, participants rated remaining domains using same scale as in Round 2; a domain was recommended as "core" if ≥80% of participants rated it ≥9 and as "optional" if ≥80% rated it ≥7.

RESULTS

A total of 178 individuals from 26 countries participated; 85 completed all survey rounds. Only one domain, "ability to participate in daily activities", met criteria for a core domain; 25 domains met criteria for an optional recommendation: 8 Patient Impacts, 5 Implementation Outcomes, 5 Participant Characteristics, 3 OAMP Characteristics and 4 Clinician Characteristics.

CONCLUSION

The ability of patients with OA to participate in daily activities should be evaluated in all OAMPs. Teams evaluating OAMPs should consider including domains from the optional recommended set, with representation from all five categories and based on stakeholder priorities in their local context.

Metabolic diversity within breast cancer brain-tropic cells determines metastatic fitness

HER2+ breast cancer patients are presented with either synchronous (S-BM), latent (Lat), or metachronous (M-BM) brain metastases. However, the basis for disparate metastatic fitness among disseminated tumor cells of similar oncotype within a distal organ remains unknown. Here, employing brain metastatic models, we show that metabolic diversity and plasticity within brain-tropic cells determine metastatic fitness. Lactate secreted by aggressive metastatic cells or lactate supplementation to mice bearing Lat cells limits innate immunosurveillance and triggers overt metastasis. Attenuating lactate metabolism in S-BM impedes metastasis, while M-BM adapt and survive as residual disease. In contrast to S-BM, Lat and M-BM survive in equilibrium with innate immunosurveillance, oxidize glutamine, and maintain cellular redox homeostasis through the anionic amino acid transporter xCT. Moreover, xCT expression is significantly higher in matched M-BM brain metastatic samples compared to primary tumors from HER2+ breast cancer patients. Inhibiting xCT function attenuates residual disease and recurrence in these preclinical models.

Induction of Innate Immune Visibility of Neuroendocrine Tumors Potentiates Immune Responses and Tumor Rejection

Natural killer (NK) cells serve as an important role in suppressing tumor growth by directly attacking malignant cells. These cells recognize the tumor cells through moleclar patterns associated with oncogenic transformation. NKG2D ligands (NKG2DLs) are one of these markers present on tumor cells which can activate NK cells and T cells by interacting with NKG2D receptors on these lymphocytes. Majority of tumors express NKG2DLs. Interestingly, tumors carrying neuroendocrine features such as small cell lung cancer (SCLC) and neuroblastoma express very low level of ligands for NK cell activating receptor NKG2D (MICA, MICB, ULBP1, ULBP2, ULBP3), which may help them escape from innate immune surveillance. Further characterization of SCLC immune environment showed reduced antigen presentation, reduced infiltration of total immune cells specifically NK cells, as compared to NSCLC, a more immunogenic tumor. Transcriptional inducers of NKG2DLs did not induce NKG2DL in SCLCs due to hypo-acetylation of MICA/B region. Histone deacetylase (HDAC) inhibitors were able to induce NKG2DL on tumor cell surface. Restoring NKG2DL in preclinical SCLC and neuroblastoma models either by ectopic expression or HDAC inhibitors stimulated direct NK cell killing in co-culture assays. NKG2DL stimulation also caused potentiation of antibody directed therapies such as CD3-EpCAM in neuroendocrine tumors. In vivo studies showed suppressed tumor growth and metastasis in an NK and CD8 T cell dependent manner when NKG2DLs are stimulated. We conclude that: restoring innate immune visibility can target neuroendocrine tumors to both innate and adaptive immune cytotoxicity.

Cell-autonomous immune gene expression is repressed in pulmonary neuroendocrine cells and small cell lung cancer

Small cell lung cancer (SCLC) is classified as a high-grade neuroendocrine (NE) tumor, but a subset of SCLC has been termed “variant” due to the loss of NE characteristics. In this study, we computed NE scores for patient-derived SCLC cell lines and xenografts, as well as human tumors. We aligned NE properties with transcription factor-defined molecular subtypes. Then we investigated the different immune phenotypes associated with high and low NE scores. We found repression of immune response genes as a shared feature between classic SCLC and pulmonary neuroendocrine cells of the healthy lung. With loss of NE fate, variant SCLC tumors regain cell-autonomous immune gene expression and exhibit higher tumor-immune interactions. Pan-cancer analysis revealed this NE lineage-specific immune phenotype in other cancers. Additionally, we observed MHC I re-expression in SCLC upon development of chemoresistance. These findings may help guide the design of treatment regimens in SCLC.

Ling Cai et al. used transcriptomic profiling data of healthy lung, patient-derived small cell lung cancer cell lines, xenografts, and primary tumors to examine a link between neuroendocrine (NE) signatures and immune gene expression. Their findings suggest that cell-autonomous immune gene repression is a shared feature between healthy and tumor cells of NE lineage and may influence tumor-immune cell interaction and response to immunotherapy.

RUVBL1/RUVBL2 ATPase Activity Drives PAQosome Maturation, DNA Replication and Radioresistance in Lung Cancer

RUVBL1 and RUVBL2 (collectively RUVBL1/2) are essential AAA+ ATPases that function as co-chaperones and have been implicated in cancer. Here we investigated the molecular and phenotypic role of RUVBL1/2 ATPase activity in non-small cell lung cancer (NSCLC). We find that RUVBL1/2 are overexpressed in NSCLC patient tumors, with high expression associated with poor survival. Utilizing a specific inhibitor of RUVBL1/2 ATPase activity, we show that RUVBL1/2 ATPase activity is necessary for the maturation or dissociation of the PAQosome, a large RUVBL1/2-dependent multiprotein complex. We also show that RUVBL1/2 have roles in DNA replication, as inhibition of its ATPase activity can cause S-phase arrest, which culminates in cancer cell death via replication catastrophe. While in vivo pharmacological inhibition of RUVBL1/2 results in modest antitumor activity, it synergizes with radiation in NSCLC, but not normal cells, an attractive property for future preclinical development.

Metabolic Diversity in Human Non-Small Cell Lung Cancer Cells

Intermediary metabolism in cancer cells is regulated by diverse cell-autonomous processes, including signal transduction and gene expression patterns, arising from specific oncogenotypes and cell lineages. Although it is well established that metabolic reprogramming is a hallmark of cancer, we lack a full view of the diversity of metabolic programs in cancer cells and an unbiased assessment of the associations between metabolic pathway preferences and other cell-autonomous processes. Here, we quantified metabolic features, mostly from the ¹³C enrichment of molecules from central carbon metabolism, in over 80 non-small cell lung cancer (NSCLC) cell lines cultured under identical conditions. Because these cell lines were extensively annotated for oncogenotype, gene expression, protein expression, and therapeutic sensitivity, the resulting database enables the user to uncover new relationships between metabolism and these orthogonal processes.

Abstract IA12: Developing precision medicine-based new lung cancer therapeutics

We have used a “chemistry first” approach to discover druggable acquired vulnerabilities that have been acquired in the pathogenesis of non-small cell lung cancer (NSCLC). We screened chemical libraries (~200,000 compounds) for chemical toxins that killed subsets of NSCLC but not normal human lung epithelial cells (HBECs). We first screened a panel of 12 NSCLC lines that represented a variety of known oncogenotypes and identified chemicals with large Z scores and appropriate properties, including re-supply, chemistry, and reproducible drug response phenotypes, and from this narrowed down a list of 202 chemicals and 18 drugs with known targeting (we called our “Precision Oncology Probe” set, POPS). These and a panel of 30 clinically available drugs, targeted therapies, and drug combinations, already in use or in trials for NSCLC treatment, were then tested on a panel of 96 NSCLC lines for their drug response phenotypes in 12-point dose response curves. This information was analyzed using scanning ranked KS (Kolmogorov–Smirnov) and elastic net biostatistics approaches to identify molecular biomarkers (mutations, mRNA expression, copy number variation, protein expression, and metabolomics) that could predict for sensitivity or resistance to a particular chemical toxin or treatment regimen. From this we have discovered that our approach identifies already known molecular biomarker drug sensitivities (e.g., EGFR mutations and EGFR TK inhibitors); many clinically available chemotherapy agents have molecular biomarkers predicting preclinical model drug responses; the POP set of chemical toxins provides novel drug-response phenotype patterns in the large NSCLC panel different from those found with clinically available agents including a therapeutic window; many of the POP toxins only hit a small % (~5%) of the NSCLC panel but the POP set as a whole provides “coverage” of the entire NSCLC panel; there are simple, one- or two-component molecular biomarkers (mutations, mRNA expression) that predict responses to the different chemical toxins in the NSCLC panel; and that the molecular biomarkers provide some information on the targets and pathways involved in response to the chemical toxins. Thus, we have identified a group of chemical toxins with selectivity for subsets of NSCLC and associated tumor molecular biomarkers to facilitate their development for precision medicine and also, in some cases, information on the targets and pathways interdicted by these chemical compounds. In addition, we have discovered NSCLC predictive biomarkers for clinically available agents.

University of Texas SPORE in Lung Cancer (P50CA70907), NCI CTD2N (U01 CA176284), and CPRIT Grants.

Citation Format: John D. Minna, Elizabeth McMillan, Luc Girard, Michael Peyton, Kenneth Huffman, Dhruba Deb, Paul Yenerall, Amit Das, Longshan Li, Maithili Dalvi, Boning Gao, Yang Xie, Yonghao Yu, Suzie Hight, Rachel Vaden, Caroline Diep, Michael Roth, Bruce Posner, John MacMillan, Ralph Deberardinis, David Wheeler, John V. Heymach, Ignacio I. Wistuba, Adi Gazdar, Michael White. Developing precision medicine-based new lung cancer therapeutics [abstract]. In: Proceedings of the Fifth AACR-IASLC International Joint Conference: Lung Cancer Translational Science from the Bench to the Clinic; Jan 8-11, 2018; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(17_Suppl):Abstract nr IA12.

Abstract 2664: Identification of two small molecules with small cell lung cancer growth inhibition response profiles different from etoposide/topotecan

Small Cell Lung Cancer (SCLC) is an aggressive, highly metastatic cancer with an overall 5-year survival rate of <5% whose treatment has not changed in the past 20 years and has been designated by the US Congress and the National Cancer Institute as a “recalcitrant cancer.” SCLCs are characterized by high initial response rates to chemotherapy (platin + etoposide) and radiation therapy but relapse is almost universal within 1 year. A NCI screen of 526 clinical or clinical investigational agents in 63 SCLC lines found large response phenotype differences (Polley, JNCI (2016) 108(10): djw122) but, in general, SCLC lines were either “sensitive” or “resistant” to all drugs tested and there was no correlation with tumor molecular biomarkers, or prior chemotherapy treatment. Thus, new drugs are needed (preferably with tumor associated molecular biomarkers) that have different profiles than available agents. As part of an NCI Cancer Treatment Discovery and Development Network (CTD2N) consortium we have screened large chemical libraries and identified chemical compounds that kill subsets of non-small cell lung cancers (NSCLCs) but not normal lung epithelial cells thus displaying a “therapeutic window” and tumor specificity. We first tested 116 of these compounds against 4 SCLC lines and found 30 that displayed dose dependent SCLC toxicity. We have so far tested 2 (SW034510, SW140154) compounds against a panel of 22 SCLC lines, which were also in the NCI screen, along with etoposide and topotecan as comparators, using 8-point dose response curves, for effect on SCLC growth inhibition. The SCLC lines (all with p53 and Rb mutations) were also phenotyped for expression of Myc family members (c-, N-, and L-), lineage transcription factors ASCL1 and NeuroD1 and neuroendocrine mRNAs. As found by Polley et al, etoposide and topotecan response phenotypes were correlated with each other (r2 = 0.7). By contrast, our two compounds, SW034510 and SW140154, response phenotypes did not correlate with etoposide/topotecan (r2 values of <0.08, and 0.1 respectively) and did not correlate with each other. Both agents cause cell death as assessed by the CellTox Green Assay suggesting efficacy across the ASCL1/NeuroD1, Myc family expression profiles. Cleaved caspase-3 western blot shows SW034510 causes caspase induced apoptosis. Cell cycle analysis suggests SW140154 causes a G1 cell cycle arrest. SARM1 gene expression anti-correlates with SW140154 IC50s. In conclusion, starting with chemical compounds that have selectivity for NSCLC, we have identified two new chemical compounds with specificity for subsets of NSCLC over normal lung epithelial cells, and which also inhibit the growth/kill subsets of SCLC in patterns different from the established therapy. Thus, these two new compounds provide potentially new therapeutic opportunities for SCLC patients resistant to current chemotherapies.

Citation Format: Allison A. Mootz, Michael Peyton, Paul Yenerall, Kimberley Avila, Kenneth Huffman, Tomohiro Haruki, Mahboubeh Papari-Zareei, Victor Stastny, Luc Girard, Elizabeth McMillan, Michael Roth, John MacMillan, Bruce Posner, Michael White, Gazdar Adi, John Minna. Identification of two small molecules with small cell lung cancer growth inhibition response profiles different from etoposide/topotecan [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2664.

Abstract 907: Uptake of lung cancer exosomes induces migratory and invasive phenotypic changes in lung epithelial cells in an oncogene context dependent manner

Cancer-derived exosomes are intracellular signaling organelles that can act via inter-cellular communication to help cancer cells invade neighboring tissues and prime metastatic sites for cancer cell spread. Lung cancer is a highly metastatic disease, with metastases often occurring when tumors are in a clinically early stage. Little is known of how lung cancer exosomes influence the migratory/ invasive phenotype of lung cancer cells. We studied migration and invasion mechanisms by transferring cancer-derived exosomes to recipient cells including cancer cells, human bronchial epithelial cells (HBECs) cells, and HBECs that we had modified with common lung cancer oncogenic changes. Exosomes isolated from lung cancer line H1299 cells (p53null, NRAS mutant) and non-malignant, immortalized HBEC3-KT cells were characterized for exosome content and type by nanoparticle tracking analysis, electron microscopy, western blotting with antibodies directed at HSP70 and CD63, and generation of H1299 and HBEC3-KT derivatives stably transfected with CD63-GFP, releasing green fluorescence exosomes for tracking purposes. Exosomes were isolated using a variety of published methods and the amount quantified: 106 H1299 and HBEC-3KT cells produced 9 x 109 and 7 x 109 exosomes of similar size (125.4nm and 129.8nm). Effect of exosomes from cancer and HBECs were tested on: 1. cell motility and invasiveness of HBECs and their oncogenic derivatives determined by transwell chamber migration assay and scratch assay; 2. vascular leakiness properties in the lung by evaluating mouse lung endothelial permeability after exosomes were injected (an early event in metastatic spread for the migrated cells); and 3. xenograft tumor formation. We found CD63-GFP exosomes from H1299 and HBEC3-KT are actively incorporated by all of the cell types. However, only H1299 exosomes (but not HBEC3-KT exosomes) induced migratory/invasive phenotypic and morphologic changes and they did this in a concentration-dependent manner in lung cancer cells and HBECs with oncogenic changes (HBEC sh-p53+KRASv12 and sh-p53+KRASv12+c-MYC manipulated HBECs) but not in the parental HBEC3-KT cells. Also, H1299 exosomes but not HBEC3-KT exosomes enhanced the lung endothelial permeability as evaluated by the extravasated dextran leaking. NSCLC H1299 cells when injected with its own exosomes produced better xenograft takes compared to H1299 cells alone. Lung cancer-derived exosomes compared to exosomes derived from immortalized but non-malignant human bronchial epithelial cells induced an increased migratory/invasive phenotype with lung vascular leakiness and higher xenograft tumor take rates. However, they induced these changes only in the context of key oncogenic changes. These results suggest understanding and targeting the mechanism of such lung cancer derived exosome behavior could lead to novel therapeutic strategies.

Citation Format: Yoshihisa Shimada, Paul Yenerall, Kimberly Avila, Hyunsil Park, Brenda Timmons, Kenneth Huffman, Boning Gao, Dhruba Deb, Maithili Dalvi, John D. Minna. Uptake of lung cancer exosomes induces migratory and invasive phenotypic changes in lung epithelial cells in an oncogene context dependent manner [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 907. doi:10.1158/1538-7445.AM2017-907

ESR1 mutations affect anti-proliferative responses to tamoxifen through enhanced cross-talk with IGF signaling

The purpose of this study was to address the role of ESR1 hormone-binding mutations in breast cancer. Soft agar anchorage-independent growth assay, Western blot, ERE reporter transactivation assay, proximity ligation assay (PLA), coimmunoprecipitation assay, silencing assay, digital droplet PCR (ddPCR), Kaplan-Meier analysis, and statistical analysis. It is now generally accepted that estrogen receptor (ESR1) mutations occur frequently in metastatic breast cancers; however, we do not yet know how to best treat these patients. We have modeled the three most frequent hormone-binding ESR1 (HBD-ESR1) mutations (Y537N, Y537S, and D538G) using stable lentiviral transduction in human breast cancer cell lines. Effects on growth were examined in response to hormonal and targeted agents, and mutation-specific changes were studied using microarray and Western blot analysis. We determined that the HBD-ESR1 mutations alter anti-proliferative effects to tamoxifen (Tam), due to cell-intrinsic changes in activation of the insulin-like growth factor receptor (IGF1R) signaling pathway and levels of PIK3R1/PIK3R3. The selective estrogen receptor degrader, fulvestrant, significantly reduced the anchorage-independent growth of ESR1 mutant-expressing cells, while combination treatments with the mTOR inhibitor everolimus, or an inhibitor blocking IGF1R, and the insulin receptor significantly enhanced anti-proliferative responses. Using digital drop (dd) PCR, we identified mutations at high frequencies ranging from 12 % for Y537N, 5 % for Y537S, and 2 % for D538G in archived primary breast tumors from women treated with adjuvant mono-tamoxifen therapy. The HBD-ESR1 mutations were not associated with recurrence-free or overall survival in response in this patient cohort and suggest that knowledge of other cell-intrinsic factors in combination with ESR1 mutation status will be needed determine anti-proliferative responses to Tam.

Abstract 3562: Protein palmitoylation in breast cancer: DHHC5 palmitoyltransferase as a potential therapeutic target

Protein S-palmitoylation is a widespread and dynamic post-translational modification that regulates protein-membrane interactions, protein-protein interactions, and protein stability. S-palmitoylation is catalyzed by members of a family of 23 palmitoyl acyl transferases, termed the DHHC family due to the presence of a common catalytic motif. The role of protein palmitoylation in cancer is largely unexplored.

In our previous study, we have shown that DHHC5 palmitoyltransferase supports the growth of non-small cell lung cancer. To further investigate the role of DHHC5 in cancer, we expanded our study to include breast cancer cell lines. Stable knockdowns of DHHC5 were undertaken in 8 breast cancer cell lines (including 4 “triple-negative” breast cancer lines) as well as in two normal human mammary epithelial cell lines (HMECs) using lentiviral shRNAs. The protein levels of DHHC5 were analyzed by immunoblotting, which all showed efficient knockdown. Cell proliferation and anchorage-dependent/ independent colony formation assays indicated that DHHC5 knockdown led to cell growth arrest and decreased cell clonogenicity in most of the tested breast cancer cell lines in vitro, but not in the HMECs. BT-549, SkBr3 and T-47D cell lines were particularly dependent on DHHC5 expression, and rescue experiments involving ectopic plasmid-driven DHHC5 and its catalytic mutant DHHS expression are in progress. In vivo tumor formation assays will be carried out by injecting MCF-7 and T-47D control cells and DHHC5 stable knockdown cells as well as rescued cells subcutaneously into NOD/SCID mice. Tumor xenograft formation will be measured.

As DHHC5 function is needed for optimal breast cancer cell growth, it will be important to identify physiologically relevant substrates in order to develop inhibitors of DHHC5 function. Future plans include microarray and protein kinase array analysis to identify possible signaling pathways in which DHHC5 may be involved, as well as palmitoyl-protein profiling of control and knockdown DHHC5 cell lines by mass spectrometry.

Citation Format: Hui Tian, Xiaoxia Qi, Kenneth Huffman, John Minna, Sandra L. Hofmann. Protein palmitoylation in breast cancer: DHHC5 palmitoyltransferase as a potential therapeutic target. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3562. doi:10.1158/1538-7445.AM2015-3562

Abstract 4779: RUVBL1 and RUBVL2 are chromatin remodelers that represent prognostic and novel therapeutic targets for a subset of non-small cell lung cancers (NSCLCs)

RUVBL1 and RUVBL2 (collectively referred to as RUVBL1/2) are AAA+ ATPases that function in various chromatin remodeling complexes. We found that RUVBL1/2 are overexpressed (n = 224) and prognostic of patient outcome in NSCLC patients (n = 697) who undergo surgical resection (combined TCGA, KMPlot.com, and SPORE P50CA70907 dataset analyses). To assess the importance and biological functions of RUVBL1/2 in NSCLC, we measured cell growth following depletion of RUVBL1/2 in 24 NSCLC lines, representing a spectrum of oncogenotypes and histologies, and 2 normal human bronchial epithelial cell lines (HBECs) using two independent RNAi reagents. Growth inhibitory phenotypes ranged from 19-87% and were “rescued” by exogenous expression of an RNAi-resistant cDNA construct, indicating “on-target” siRNA effects. Four of the 23 NSCLCs were very sensitive (>75% growth inhibition), while 88% of NSCLCs were more growth inhibited than HBECs, indicating a therapeutic window. To establish molecular biomarkers of RUVBL1/2 dependency, we correlated whole exome mutation status, whole transcriptome mRNA levels, and a number of other parameters to sensitivity to RUVBL1/2 depletion. Sensitivity to RUVBL1/2 knockdown did not correlate with the mutation status or expression of any genes. However, sensitivity to RUVBL1/2 depletion did correlate with doubling time. Flow cytometry analysis in NSCLC lines sensitive to RUVBL1/2 KD revealed that RUVBL1/2 depletion resulted in a G2/M arrest (but not apoptosis), and a decrease in cell cycle related transcripts, such as CDKN3, AURKA, CIT and CDC20, whereas resistant cell lines do not exhibit these changes. Initial ChIP-seq analysis suggests that RUVBL1/2 preferentially occupies cell cycle related genes and are depleted in nucleosome free regions (i.e. transcription start sites). These results, combined with results from others demonstrating the necessity of ATP hydrolysis for RUVBL1/2's function(s), indicate that the chromatin remodelers RUVBL1/2 are potential therapeutic targets in a subset of NSCLCs. (Supported by UTSW Green Center Fellowship, CPRIT RP120732, SPORE P50CA70907)

Citation Format: Paul M. Yenerall, Rahul Kollipara, Ryan Carstens, Kenneth Huffman, Luc Girard, Jaime Rodriguez, Ignacio Wistuba, David Mangelsdorf, John Minna, Ralf Kittler. RUVBL1 and RUBVL2 are chromatin remodelers that represent prognostic and novel therapeutic targets for a subset of non-small cell lung cancers (NSCLCs). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4779. doi:10.1158/1538-7445.AM2015-4779

Abstract 4619: Protein palmitoylation in non-small cell lung cancer (NSCLC): DHHC5 palmitoyltransferase as a potential therapeutic target

Post-translational palmitoylation of intracellular proteins is mediated by protein palmitoyltransferases (PAT) belonging to the DHHC family, which share a common catalytic Asp-His-His-Cys (DHHC) motif. According to a genome-wide siRNA screen scoring for growth suppression in over 50 non-small cell lung cancer (NSCLC) cell lines, DHHC family members are strikingly over-represented. Among the tested DHHC palmitoyltransferases, knockdown of DHHC5 showed cell growth inhibition in many cell lines in the initial screen.

To further investigate the growth suppression in response to DHHC5 depletion, transient and stable knockdowns of DHHC5 were undertaken in a dozen of NSCLC cell lines identified in the genome-wide screen using siRNAs and lentiviral shRNAs. Such knockdown was also performed in three immortalized human lung bronchial epithelial cell lines (HBECs). The gene expression and protein levels of DHHC5 were analyzed by RT-PCR and immunoblotting, both of which showed efficient knockdown levels. Cell proliferation and anchorage-dependent/independent colony formation assays indicated that DHHC5 knockdown led to cell growth arrest and decreased cell clonogenicity in most of the tested NSCLC cell lines in vitro, but not in the HBECs. H1299, H358 and H2009 cell lines were particularly dependent on DHHC5 expression and the growth-suppression phenotype of DHHC5 stable knockdown H1299/H358/H2009 cells was rescued by overexpression of DHHC5. The catalytically inactive DHHC5 mutant was not able to provide rescue. In vivo tumor formation assays were then carried out by injecting H1299 and H358 control cells and DHHC5 stable knockdown cells subcutaneously into NOD/SCID mice. DHHC5 knockdown led to absence or dramatically decreased tumor xenograft formation. Furthermore, a Tet-On inducible system with TRIPZ shRNA lentiviral delivery was established in H1299. Mouse xenografts using this H1299 Tet-on inducible cell line showed similar results.

As DHHC5 function is needed for optimal lung cancer cell growth, it will be important to identify physiologically relevant substrates in order to develop inhibitors of DHHC5 function. Future plans include microarray and protein kinase array analysis to distinguish possible signaling pathways in which DHHC5 may be involved, as well as palmitoyl-protein profiling of normal and knockdown DHHC5 cell lines by mass spectrometry.

Citation Format: Hui Tian, Jui-Yun Lu, Chunli Shao, Kenneth Huffman, Ryan Carstens, John D. Minna, Sandra L. Hofmann. Protein palmitoylation in non-small cell lung cancer (NSCLC): DHHC5 palmitoyltransferase as a potential therapeutic target. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4619. doi:10.1158/1538-7445.AM2014-4619

Abstract 1525: Exome sequencing to identify permissive mutations representing acquired vulnerabilities in lung cancer

When a lung epithelial cell acquires a driver mutation (e.g. in KRAS) it often needs to acquire additional ‘permissive’ genetic alterations to enable the cell to tolerate the oncogenic change. These ‘permissive' alterations represent an ‘acquired vulnerability' and consequently a novel therapeutic target in lung cancers driven by known, but currently un-targetable, driver mutations. Immortalized Human Bronchial Epithelial Cells (HBECs) represent a cell appropriate in vitro model to study the origin and pathogenesis of lung cancer following introduction of defined oncogenic changes. We have previously transformed HBECs to full malignancy by introducing five genetic manipulations (to CDK4, TERT, TP53, KRAS, MYC, BCL2, PTEN and/or STK11). While malignant transformation will be largely driven by the exogenous oncogenotype -i.e. the introduced oncogenic alterations- we hypothesize the cells also must undergo additional somatic ‘permissive' changes to bypass anti-tumor mechanisms. While lung cancers are often highly mutated (mainly due to carcinogens in cigarette smoke), manipulated HBECs should exhibit fewer somatic mutations, providing greater power to identify important somatically acquired mutations that facilitate tumorigenic progression of lung epithelial cells.

We have sequenced the exomes of a series of 22 genetically manipulated HBECs derived from two individuals and representing 15 unique oncogenotypes (combinations of 3-5 introduced manipulations). Paired-end sequencing was performed with an Illumina HiSeq 2000 using a VCRome 2.1 liquid capture design ‘exome chip’. The median fold coverage was 114X, resulting in at least 90% of targeted bases are covered at >20-fold. Somatic mutations were called by comparing manipulated HBECs to their immortalized parental cell line.

Manipulated HBECs had a median somatic mutation rate of 0.92 mutations/Mb, 7-9-fold lower than observed in lung cancers and tumor cell lines. The median mutation rate increased with the number of introduced manipulations (HBECs with three, four and five manipulations had 0.47, 0.97 and 0.92 mutations/Mb, respectively). Non-synonymous somatic mutations were identified in 470 genes. Thirty-nine genes were mutated in ≥3 HBECs (recurrent mutations) and of these, 35 genes (none currently regarded as ‘driver’ oncogenes and 5 potentially ‘druggable' [DGIdb]) were also mutated in primary lung adenocarcinoma and squamous cell carcinomas (TCGA data).

We found the introduction of defined oncogenic alterations in HBECs is accompanied by the acquisition of somatic mutations. Leveraging against public somatic mutation data for lung tumors has allowed us to prioritize mutations for follow up to better identify potential acquired vulnerabilities in lung cancer cells and therefore, novel therapeutic targets.

Citation Format: Jill E. Larsen, Caleb F. Davis, Kenneth Huffman, Luc Girard, David A. Wheeler, Richard A. Gibbs, John D. Minna. Exome sequencing to identify permissive mutations representing acquired vulnerabilities in lung cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1525. doi:10.1158/1538-7445.AM2014-1525

Abstract IA21: Developing a new functional classification of lung cancer based on tumor acquired vulnerabilities

We have been comprehensively screening for “vulnerabilities” that have been acquired during the multi-step pathogenesis of lung cancer cells but are not present in normal lung epithelial cells to identify genetic and chemical perturbations that will selectively kill lung cancer. We think many of these have occurred to allow the lung cancers to undergo/tolerate “oncogene addiction.” We tested a sub-panel of 12-15 non-small cell lung cancer (NSCLC) lines that covers the known molecular spectra of lung cancer with genome wide siRNA and large scale chemical library (~250,000 compounds) and natural products in vitro screens to identify “hits” that will kill (suppress the growth of) lung cancer cells but not normal human bronchial epithelial cells and that also only kill a subset of lung cancer cells providing two types of specificity. “Hits” from these broad screens are then tested (including detailed drug concentration curves) across a large panel of lung cancer lines (~100) representing a variety of lung cancer histologic and molecular oncogenotypes. Other versions of these screens include the intensive use of “mini-libraries” each containing 50 – 150 gene targets by siRNAs or shRNAs, or ~200 defined drugs to explore pathways in detail in tests of over 70 NSCLCs. Examples include: nuclear receptors and their co-regulators (120 genes); cancer stem cell pathways (50 genes); chromatin remodelers (75 genes) and identified lung cancer mutated driver oncogenes (175 genes). In addition to the in vitro tests, we have developed in vivo (xenograft) tests where shRNA mini-libraries are introduced into tumor cells at high representation which are grown as xenografts, analyzed by NexGen sequencing and shRNAs identified that drop out or are retained in xenografts compared to in vitro grown cells to identify vulnerabilities that are only detected in the in vivo situation. All of the data are then related to the large legacy molecular datasets associated with the lung cancer lines (including whole exome sequence analyses and genome wide mRNA, copy number variation, methylation, miR expression data and proteomics data). In addition, detailed chemical and pharmacokinetic analyses for favorable drug properties and subsequent chemical modifications also occur for the chemical compounds to progress those towards potential clinical studies. The results of all of these analyses have identified ~300 new chemical compounds and ~300 genetic hits all of which show selectivity for lung cancer over normal lung cells and selectivity for subtypes of lung cancer. The chemical and genes hits are being compared to the tumor molecular information and integrated in turn through a “connectivity map” type of approach – to identify drugs and gene hits involving the same pathways. The molecular correlates of the tumor lines are related to similar molecular changes in patient derived xenografts and patient tumor specimens to provide a connection of the molecular subtype-selective vulnerabilities (“enrollment biomarkers”) between the preclinical response phenotypes and patient tumor specimens. From these data we find lung cancers can be classified into groups (“clades”) that represent functional vulnerabilities to the gene and chemical compound hits and these in turn can be related to molecular abnormalities in tumors. One example of this is our detailed analyses a matched lung adenocarcinoma/normal lung epithelial cell model derived from the same patient which identified three distinct target/response-indicator pairings that are represented a significant frequencies (6-16%) in the lung adenocarcinoma population (Kim et al. Cell 155:552, 2013). These include three totally novel lung cancer selective targeted therapies: NLRP3 mutation/inflammasome activation-dependent FLIP addiction; co-occurring KRAS and LKB1 mutation-driven COPI addiction; and selective sensitivity to a synthetic indolotriazine that is specified by a seven-gene expression signature. Our panel of “hits” provide the opportunity to identify all potential therapeutic targets for lung cancer, while the molecular correlates will allow “personalization” of these new therapies going forward in preclinical and clinical translation. (Supported by NCI SPORE P50CA70907, NCI CTD2N, CPRIT, UTSW CCSG P30CA142543)

Citation Format: John D. Minna, Adi Gazdar, Alexander Augustyn, Rebecca Britt, Ryan Carstens, Patrick Dospoy, Boning Gao, Luc Girard, Suzie Hight, Kenneth Huffman, Jill Larsen, Michael Peyton, Chunli Shao, David Mangelsdorf, Rolf Brekken, Ralph Deberardinis, Pei-Hsuan Chen, Carmen Behrens, Lauren Byers, John Heymach, Jack Roth, Ignacio Wistuba, Yang Xie, Caleb Davis, David Wheeler, Richard Gibbs, Edward Marcotte, Joseph Ready, Deepak Nijhawan, Noelle Williams, Steven McKnight, Bruce Posner, John MacMillan, Michael Roth, Michael White. Developing a new functional classification of lung cancer based on tumor acquired vulnerabilities. [abstract]. In: Proceedings of the AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer; 2014 Jan 6-9; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2014;20(2Suppl):Abstract nr IA21.

Pre-clinical studies of epigenetic therapies targeting histone modifiers in lung cancer

Treatment options for lung cancer patients have been generally limited to standard therapies or targeted interventions which involve a small number of known mutations. Although the targeted therapies are initially successful, they most often result in drug resistance, relapse, and mortality. We now know that the complexity of lung cancer comes not only from genomic changes, but also from aberrant epigenetic regulatory events. Epigenetic therapies have shown promise as single agents in the treatment of hematological malignancies but have yet to meet this expectation in solid tumors thus fostering researchers to pursue new approaches in the development and use of epigenetic interventions. Here, we review some recent pre-clinical findings involving the use of drugs targeting histone modifying enzymes both as single agents and as co-therapies against lung cancer. A greater understanding of the impact of these epigenetic compounds in lung cancer signaling is needed and further evaluation in vivo is warranted in several cases based on the pre-clinical activity of a subset of compounds discussed in this review, including drugs co-targeting HDACs and EGF receptor, targeting Brd4 and targeting Jumonji histone demethylases.

Abstract A24: Targeted synthetic lethal screens to identify acquired vulnerabilities in a novel class of ASCL1-dependent neuroendocrine non-small cell lung cancers

Introduction: Gene expression signatures from large cohorts of lung tumors suggest that distinct neuroendocrine (NE) cancers with poor prognosis appear in ~10% of otherwise pathologically unremarkable NSCLCs. However, a complete molecular characterization is lacking because a similar subtype has yet to be identified in a significant number of lung cancer cell lines. Our goal is to develop a pre-clinical model for NSCLC-NE and use it to rationale targeted therapy for this important subtype of lung cancer. We are developing targeted siRNA-based synthetic lethal screens to identify acquired vulnerabilities in lung cancers by using “mini-libraries” of putative cancer stem cell genes (CSC, N = 40), nuclear receptors and their co-regulators (NR/CoReg, N = 120), chromatin remodelers (CR, N = 102), and ASCL1-regulated druggable genes (N = 40). The siRNA libraries were derived from multiple studies while the ASCL1-targeted library was developed from our own ChIP-Seq data.

Identifying NSCLC-NE Cell Lines: Using mRNA expression signatures from 207 lung cell lines (NSCLC/SCLC/HBEC) we identified a cluster of NSCLC cell lines (9% of NSCLC) that express genes indicative of a neuroendocrine phenotype (NSCLC-NE). A highly expressed gene in this class of cell lines is the lineage-specific transcription factor ASCL1, which is required for the development of pulmonary neuroendocrine cells. ASCL1 loss-of-function studies demonstrate dramatic cell death compared to controls, suggesting these cells are addicted to ASCL1 for survival.

ASCL1 ChIP-Seq Analysis: To better understand the molecular pathogenesis of ASCL1-dependent NSCLC-NEs and identify druggable therapeutic downstream targets, we performed ChIP-Seq analysis on six ASCL1+ and two ASCL1- cell lines. A 125-member “ASCL1-signature” was generated and tested on multiple resected NSCLC datasets (N > 800 patients) for prognostic utility and tumors that exhibited the “ASCL1 signature” had significantly worse prognosis. A target of ASCL1 as determined by ChIP-Seq analysis is the anti-apoptotic regulator BCL2. BCL2 knockdown using siRNA as well as inhibition of BCL2 using a small molecule (ABT-263) results in cell death that is specific to ASCL1+/BCL2+ cells.

ASCL1 Upstream Regulation: A separate therapeutic avenue is to determine upstream regulators of ASCL1 and we have demonstrated that ASCL1 participates in a double-negative feedback loop with the MEK/ERK pathway. Pharmacological activation of the MEK/ERK pathway results in loss of ASCL1 mRNA and protein, and induces apoptosis in ASCL1-dependent NSCLC-NE lines. Additionally, siRNA-mediated knockdown of ASCL1 results in reciprocal activation of the MEK/ERK pathway even in the presence of an siRNA targeting MEK1. Combining MEK/ERK activators with ABT-263 results in dramatic induction of apoptosis in NSCLC-NE while sparing normal immortalized HBEC cells suggesting the possibility of a synthetic lethal combination therapy for this subset of tumors.

Synthetic Lethal Screens: We have completed synthetic lethal siRNA screens for the CSC, NR/CoReg, and CR mini-libraries using a panel of lung cancer lines. Optimal transfection conditions were established for each line and siRNA pools were used with multiple (n = 9) replicates providing great reproducibility (r > 0.9). From these screens, preliminary data demonstrates that the NSCLC-NE tumor lines have response phenotypes distinct from all other classes of lung cancer.

Conclusions: We show that NE gene expression in NSCLC is of clinical relevance, and ASCL1 appears to be a lineage-dependent oncogene for NSCLC-NE. ASCL1 ChIP-Seq and siRNA screen data provide a roadmap for systematically searching for therapeutic targets such as BCL2 while work focused on targeting pathways upstream of ASCL1 also demonstrates clinical potential for NSCLC with neuroendocrine features. Our results indicate that lung cancers driven by ASCL1 have distinct acquired vulnerabilities. (Supported by NCI SPORE P50CA70907, CPRIT)

Citation Format: Alexander Augustyn, Mark Borromeo, Tao Wang, Chunli Shao, Patrick Dospoy, Kenneth Huffman, Ryan Carstens, Luc Girard, Carmen Behrens, Ignacio Wistuba, Yang Xie, Jane Johnson, Adi Gazdar, John Minna. Targeted synthetic lethal screens to identify acquired vulnerabilities in a novel class of ASCL1-dependent neuroendocrine non-small cell lung cancers. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr A24.

Abstract 5589: Molecular signatures of in vitro drug response in lung cancer

We are developing in vitro drug response signatures based on profiling of mRNA (Illumina WG6-V3 arrays), DNA mutation (COSMIC and deep sequencing), DNA copy number (Illumina Human1M-Duov3 SNP array) and DNA methylation (Illumina HumanMethylation450) from lung cancer cell lines to predict which drugs a patient's tumor is most likely to respond to. We have generated drug response phenotypes (MTS colorimetric assays) for ∼25 standard, targeted, and new chemotherapy agents and combinations for ∼ 100 non-small cell lung cancer (NSCLC) lines. All assays were done in triplicates or more and were very reproducible over time (r > 0.8). More than 10,000 MTS assays were generated and we designed a high-throughput database software named DIVISA (Database of In VItro Sensitivity Assays) for the purpose of storing and analyzing these assays. Some drugs showed a wide range of sensitivities (> 10,000-fold in IC50 values) and IC50 clustering indicates that drug response phenotypes can be grouped according to drug types. As part of a joint NCI SPORE, NCI SPECS, and DOD PROSPECT effort we have collected 275 clinically annotated frozen tumors with drug response information including 94 that represent lung cancer resection followed by adjuvant treatment. These specimens have also been profiled on Illumina expression arrays to formally test the clinical relevance of the tumor cell line signatures, and to verify that the signatures predict for response only in the presence of treatment and thus are not prognostic of survival in the absence of treatment. In addition, we have 3 primary tumor datasets totaling 96 specimens with EGFR mutation information, thus providing a validation set for EGFR tyrosine kinase inhibitor signatures. Using a weighted voting classification, cell line signatures predicted drug response in primary tumors with accuracies of ∼65% for targeted therapy (EGFR) but with somewhat lower accuracies for platin/taxane therapies suggesting that cell line predictive signatures may be better suited for targeted drugs. To facilitate translation to clinical trials we are working with High Throughput Genomics (HTG) to develop quantitative mRNA profiles that are performed on formalin fixed paraffin embedded (FFPE) material on a platform that can be transferred to a CLIA certified environment. These studies thus provide a preclinical human tumor model platform for systematically testing new drugs and for developing signatures to guide their most efficient use in early clinical tests. Funded by University of Texas SPORE in Lung Cancer (P50CA70907) and NCI SPECS Lung Cancer (CA114771).

Citation Format: Luc Girard, Michael Peyton, Ignacio Wistuba, Yang Xie, Rachel Greer, Milind B. Suraokar, Carmen Behrens, Guanghua Xiao, John Heymach, David A. Wheeler, Caleb F. Davis, Kenneth Huffman, David S. Shames, Kevin R. Coombes, Adi F. Gazdar, David CL Lam, David G. Beer, John D. Minna. Molecular signatures of in vitro drug response in lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5589. doi:10.1158/1538-7445.AM2013-5589

Abstract 1474: An RNAi-based functional classification of lung cancer reveals recurring subgroups strongly correlated with EMT status

Introduction: Personalized therapeutic approaches which stratify patients into subgroups based on mutation, amplification, or expression profiles have proven effective. Previously, we showed that mRNA expression profiling of nuclear receptors (NRs) segregated NSCLC patients into prognostic groups. Using a gene-library knockdown strategy, we aim to demonstrate the diagnostic and therapeutic value of NRs and their co-regulators (Co-Regs).

Aims and Methods: We used a large panel of lung and breast cell lines of various types to develop a patient stratification scheme based on functional/survival response to pooled siRNA “mini” library screens. The first siRNA mini-library consists of 48 NR and 72 CoReg targets. Screens were performed in triplicate across a panel of 54 lung cancers (NSCLC and SCLC), 20 breast cancers, 6 immortalized human bronchial epithelial cell lines (HBECs), and a series of oncogenically progressed HBECs. Each triplicate assay was repeated three times using optimized transfection conditions and followed by statistical analysis (r>0.83 for replicate screens). A second siRNA library targeting 53 chromatin remodelers, 26 jumonji enzymes, and 23 palmitoyl transferases was also screened against these same lines using the same protocol.

Results and Conclusions:

1) Response (inhibition or stimulation of growth) to any given siRNA knockdown was heterogeneous across the panel, reflecting the high degree of genetic/functional variability between cancer lines.

2) 85% of the siRNA knockdowns reduced viability in at least one tumor line. Several knockdowns demonstrated selective killing of a significant portion of the cancer lines but not the “normal” HBECs. Many knockdowns differentially affected subsets of cell lines (suggesting possible personalized therapeutics) while others uniformly affected nearly the entire panel.

3) Screening a series of oncogenically progressed HBECs (with p53, KRAS, LKB1) revealed new vulnerabilities detected by a change in response to NR/CoReg knockdown, highlighting the underlying biological changes accompanying oncogenesis.

4) Unexpectedly, we found that classification of the tumor cells by the NR/CoReg mini-library was similar to the classification derived from the second library. The two libraries independently produced a similar subgrouping of the tumor panel. Combined analysis of the two libraries found similar groups.

5) Although there was no obvious correlation between oncogenotypes or mRNA expression of individual NRs or CoRegs, one subgroup (n=26) consisted almost exclusively of lines that had undergone EMT, suggesting possible subtypes of mesenchymal cells.

We conclude that siRNA-minilibrary screens targeting NRs, CoRegs, and chromatin remodeling genes provide a new functional classification of lung and breast cancer with strong translational potential. Work funded by CPRIT.

Citation Format: Ryan Carstens, Kenneth Huffman, Shuguang Wei, Luc Girard, Yang Xie, Sandra Hofmann, Ignacio Wistuba, Suzanne Fuqua, Bruce Posner, Adi F. Gazdar, Steven Kliewer, Bert O'Malley, David Mangelsdorf, John D. Minna. An RNAi-based functional classification of lung cancer reveals recurring subgroups strongly correlated with EMT status. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1474. doi:10.1158/1538-7445.AM2013-1474

Feed restriction delays developmental fast skeletal muscle myosin heavy chain isoforms in turkey poults selected for differential growth

Genetic selection has been very successful at significantly increasing BW and breast muscle proportion in commercial broiler and turkey strains. The mechanisms of breast muscle growth in poultry and the interactive effects of nutritional status and selection are not fully understood. The hypothesis underlying the current study is that feed restriction, simply as a vehicle for controlling early growth, would delay the temporal expression pattern of neonatal (nMyHC) and adult (aMyHC) fast skeletal muscle myosin heavy chain (MyHC) isoforms in the pectoralis major muscle of turkey poults. The poultry growth model used to evaluate this hypothesis consisted of a randombred control turkey line (RBC2) that represents commercial turkeys of the 1960s and a line developed from the RBC2 by selection for BW at 16 wk of age (F line). The F line has significantly heavier breast muscles than the RBC2 concomitant with increased BW, but the proportion of breast muscle relative to BW is similar. A quantitative indirect ELISA using fast skeletal MyHC isoform specific monoclonal antibodies revealed no significant line differences in the temporal expression of posthatch fast skeletal muscle MyHC in ad libitum fed poults. Feed restriction, however, altered the temporal expression patterns of nMyHC and aMyHC in both F line and RBC2 poults compared with the poults fed ad libitum.

Abstract 5757: A new functional classification of lung and breast cancers based on siRNA mediated knockdown of 48 NRs and 72 CoRegulators

Introduction: Nuclear receptors (NRs) and their co-regulators (CoRegs) are master regulators of key transcriptional processes important in cancer pathogenesis and could provide molecular biomarkers for prognosis and personalizing new cancer targeted therapy. Aims and Methods: Our goal is to functionally classify a panel of 54 lung cancer, 20 breast cancer, and several immortalized human lung and breast epithelial cell strains based on their growth and survival response to siRNA mediated knockdown of 48 NRs and 72 CoRegs. Following knockdown of individual NR/CoRegs, changes in growth patterns are quantified and statistical methods are used to identify disease subgroups of similar responders. These subgroups are then integrated with our legacy datasets for clinical demographics, cancer cell oncogenotype and genome wide molecular characterization, and responses to standard and targeted chemotherapy. Results and Conclusions: A diverse, representative panel consisting of lung cancer, breast cancer, and normal epithelial cell lines was tested by siRNA transfection. After optimization to determine transfection conditions, all cell lines were screened using a focused siRNA library targeting all 48 NRs and 72 CoRegs (each gene is targeted by pools of 4 different siRNAs, Qiagen). Screening experiments were performed in triplicate, in 96 well plates, in a five-day MTS assay and assays were repeated 3 times. Correlation between replicates for the same cell line is >0.84 and knockdowns were validated by qRT-PCR. We found: 1) NR/CoReg-specific knockdown could have no effect, increase, or decrease tumor cell viability in a cell line dependent manner. 2) Overall ∼70% of the NRs or CoRegs reduced cell viability in at least one tumor line when their expression was knocked down (examples included NURR1, PRMT1, RXRalpha, BRCA1). 3) NR/CoReg-specific tumor cell toxicity was validated independently by siRNA knockdown combined with a liquid colony formation assay. 4) Knockdown of several NR/CoRegs selectively killed tumor but not normal epithelial cells. 5) Tumor cell lines could be stratified into functionally unique categories based on their changes in growth following NR/CoReg-specific knockdowns. We conclude that siRNA mediated knockdown of a large number of NRs and their CoRegs identifies genes that show tumor cell selective toxicity, and that tumor lines vary in their siRNA response phenotypes. These data strengthen the concept for NR/CoReg targeted therapy of lung and breast cancer and also the need to “personalize” such therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5757. doi:1538-7445.AM2012-5757

Abstract 1309: The lineage-specific transcription factor ASCL1 defines a subtype of non-small cell lung cancer with poor prognosis

Introduction: Using genome-wide expression analyses several groups have identified a neuroendocrine subtype of NSCLC (NE-NSCLC), occurring in 5-8% of all NSCLC, which has a poorer prognosis than typical NSCLC. To determine a preclinical model for NE-NSCLC, we utilized whole-genome mRNA expression array data from 119 NSCLC cell lines to identify a class of NSCLC lines that fit the neuroendocrine phenotype. A gene expressed in all putative NE-NSCLC cell lines is the potent neural-specific transcription factor ASCL1. We found that ASCL1 is: necessary for the survival of NE-NSCLC cell lines; correlates with stem cell marker expression; and that an ASCL1-associated gene signature predicts for poor prognosis in NSCLC. Aims and Methods: We hypothesize that ASCL1 acts as a “lineage dependent oncogene” for NE-NSCLC and that associated with ASCL1's function in the molecular pathogenesis of these lung cancers will be a gene expression profile that contributes to the malignant phenotype, which will provide insight towards therapeutic targeting of this subset of NSCLC. To test this hypothesis we examined genome wide mRNA expression data from 119 NSCLC lines with validation of selected genes by qRT-PCR, ASLC1 ChIP-Seq data obtained on ASCL1 expressing NSCLC lines, the clinical outcome of a 275 resected NSCLCs characterized for ASCL1, and genome wide mRNA expression, performed functional analyses in NSCLC lines with siRNA mediated knockdown of ASCL1 and downstream target genes, and integrated this information using biostatistical and bioinformatics approaches. Results and Conclusions: We identified 11 out of 119 NSCLC cell lines (9.2%) that display a distinct neuroendocrine gene signature, and 24/275 resected NSCLCs with high ASCL1 expression. The NSCLCs expressing ASCL1 and the neuroendocrine gene signature had impaired prognosis compared to the other NSCLCs. Knockdown of ASCL1 in representative NSCLC lines reduced target gene expression, caused significant cell cycle defects, and induced apoptosis. NSCLC cell lines expressing ASCL1 demonstrate a cancer stem cell marker phenotype similar to that of small cell lung cancer, providing clues to the pathogenesis of the NE-NSCLC disease subset. ASCL1 ChIP-Seq data combined with genome wide mRNA expression data identified a subset of genes whose expression appears to be regulated by ASCL1. Our results suggest that neuroendocrine gene expression in NSCLC is of clinical relevance, that ASCL1 is required for survival of the NE-NSCLC disease subset, while the integrated ASCL1 ChIP-Seq and mRNA expression data provide a roadmap for systematically searching for therapeutic targets for this phenotype and their mechanistic role in a cancer stem cell (initiating cell) subpopulation within these tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1309. doi:1538-7445.AM2012-1309

Exercise dose response in muscle

Exercise increases peak VO2 partially through muscle adaptations. However, understanding muscle adaptations related to exercise dose is incomplete. This study investigated exercise training dose on capillaries per fiber and capillaries per area; and citrate synthase from vastus lateralis and related both to changes in peak VO2. This randomized trial compared 3 exercise doses: low amount-moderate intensity (n=40), low amount-high intensity (n=47), high amount-high intensity (n=41), and a control group (n=35). Both measures of capillary supply increased in all exercise groups (p<0.05). Low amount-high intensity and high amount-high intensity improved citrate synthase (p<0.05) and the low amount-moderate intensity citrate synthase approached significance (p=0.059). Muscle improvements were only related to improvements in peak VO2 in high amount-high intensity (citrate synthase, r=0.304; capillaries:fiber, r= - 0.318; p<0.05 and capillaries/mm2 r= - 0.310, p<0.05). These data suggest muscle adaptations occur following both low and high exercise doses, but are only related to improved peak VO2 following high amount-high intensity training.

SU-8 polymer enclosed microchannels with interconnect and nanohole arrays as an optical detection device for biospecies

We present for the first time the integration of nanohole arrays for surface plasmon resonance (SPR) sensing together with SU-8 polymer microfluidic channels containing special packaging structures for chip-to-chip and world-to-chip interconnect. Primary steps towards an optical biospecies detection device are presented including observing the effect of period on transmission peak location, examining new materials for the enclosed microchannels, and demonstrating nanohole array SPR transmission data through water contained in the microchannels. Additionally, the enclosed microchannels are integrated with interconnect structures that facilitate interfacing with macro-scale test equipment and microfluidic components and systems such as lab-on-a-chip. Results demonstrate the potential of the polymer microchannels with integrated nanohole arrays and interconnect as a packaged optical SPR detection device.

Oxidative signalling and inflammatory pathways in Alzheimer's disease

It is well established that inflammation and oxidative stress are key components of the pathology of Alzheimer's disease (AD), but how early in the pathological cascade these processes are involved or which specific molecular components are key, has not been fully elucidated. This paper describes the pharmacological approach to understand the molecular components of inflammation and oxidative stress on the activation of microglial cells and neuronal cell viability. We have shown that activation of microglia with the 42-amino-acid form of the beta-amyloid peptide (A beta 42) activates the production of cyclooxygenase-2, the inducible form of nitric oxide synthase and tumour necrosis factor-alpha and there appears to be little interactive feedback between these three mediators. Moreover, we explore the effects of a series of salen-manganese complexes, EUK-8, -134 and -189, which are known to possess both superoxide and catalase activity. These compounds are able to protect cells from insults produced by hydrogen peroxide or peroxynitrite. Moreover, EUK-134 was also able to limit the output of prostaglandin E2 from activated microglial cells. The mechanisms underlying these effects are discussed. Together, these data support a pivotal role for oxidative stress and inflammation as key mediators of the pathological cascade in AD and provide some ideas about possible therapeutic targets.

Lifespan extension and rescue of spongiform encephalopathy in superoxide dismutase 2 nullizygous mice treated with superoxide dismutase-catalase mimetics

Superoxide is produced as a result of normal energy metabolism within the mitochondria and is scavenged by the mitochondrial form of superoxide dismutase (sod2). Mice with inactivated SOD2 (sod2 nullizygous mice) die prematurely, exhibiting several metabolic and mitochondrial defects and severe tissue pathologies, including a lethal spongiform neurodegenerative disorder (Li et al., 1995; Melov et al., 1998, 1999). We show that treatment of sod2 nullizygous mice with synthetic superoxide dismutase (SOD)-catalase mimetics extends their lifespan by threefold, rescues the spongiform encephalopathy, and attenuates mitochondrial defects. This class of antioxidant compounds has been shown previously to extend lifespan in the nematode Caenorhabditis elegans (Melov et al., 2000). These new findings in mice suggest novel therapeutic approaches to neurodegenerative diseases associated with oxidative stress such as Friedreich ataxia, spongiform encephalopathies, and Alzheimer's and Parkinson's diseases, in which chronic oxidative damage to the brain has been implicated.

The effect of a pill inserter on vaginal misoprostol dosing

OBJECTIVE

To determine whether the method of placing a 25-microg misoprostol chip into the posterior fornix to achieve cervical ripening affects the drug's efficacy.

METHODS

A pill inserter was used to place a misoprostol chip into the posterior fornix for the purpose of cervical ripening prior to induction of labor. Data from a control group were obtained by retrospective chart review.

RESULTS

The control and study groups contained 49 patients each. Compared to placing the misoprostol chip with a lubricated finger, the use of the pill inserter resulted in statistically significantly more patients receiving only one dose. This occurred either because a Bishop score of 8 or greater was achieved or because repeat dosing was disallowed secondary to the onset of uterine contractions. Although the total number of patients subsequently requiring oxytocin was significantly increased, there was no difference in the use of oxytocin for either induction or augmentation of labor. The lengths of the latent and active phases of labor did not differ between the two groups.

CONCLUSION

The number of doses of a 25-microg misoprostol chip for cervical ripening that result in uterine contractions, with or without a change in the Bishop score, is affected by the method used to place it in the vagina.

Attenuation of staurosporine-induced apoptosis, oxidative stress, and mitochondrial dysfunction by synthetic superoxide dismutase and catalase mimetics, in cultured cortical neurons

Neuronal apoptosis induced by staurosporine (STS) involves multiple cellular and molecular events, such as the production of reactive oxygen species (ROS). In this study, we tested the efficacy of two synthetic superoxide dismutase/catalase mimetics (EUK-134 and EUK-189) on neuronal apoptosis, oxidative stress, and mitochondrial dysfunction produced by STS in primary cortical neuronal cultures. Exposure of cultures to STS for 24 h increased lactate dehydrogenase (LDH) release, the number of apoptotic cells, and decreased trypan blue exclusion. Pretreatment with 20 microM EUK-134 or 0.5 microM EUK-189 significantly attenuated STS-induced neurotoxicity, as did pretreatment with the caspase-1 inhibitor, Ac-YVAD-CHO, but not the caspase-3 inhibitor, Ac-DEVD-CHO. Posttreatment (1-3 h following STS exposure) with 20 microM EUK-134 or 0.5 microM EUK-189 significantly reduced STS-induced LDH release, in a time-dependent manner. Exposure of cultures to STS for 1 h produced an elevation of ROS, as determined by increased levels of 2,7-dichlorofluorescein (DCF). This rapid elevation of ROS was followed by an increase in lipid peroxidation, and both the increase in DCF fluorescence and in lipid peroxidation were significantly blocked by pretreatment with EUK-134. STS treatment for 3-6 h increased cytochrome c release from mitochondria into the cytosol, an effect also blocked by pretreatment with EUK-134. These results indicate that intracellular oxidative stress and mitochondrial dysfunction are critically involved in STS-induced neurotoxicity. However, there are additional cellular responses to STS, which are insensitive to treatment with radical scavengers that also contribute to its neurotoxicity.

6,6′-Bis(2-hydroxyphenyl)-2,2′-bipyridine manganese(III) complexes: A novel series of superoxide dismutase and catalase mimetics

A series of novel manganese(III) complexes is described based on a 6,6'-bis(2-hydroxyphenyl)-2,2'-bipyridine template. These complexes show superoxide dismutase and catalase activity. The effect of the aromatic substitution pattern on the SAR is described.

Task performance in virtual environments used for cognitive rehabilitation after traumatic brain injury

OBJECTIVE

This report describes a reliability study using a prototype computer-simulated virtual environment to assess basic daily living skills in a sample of persons with traumatic brain injury (TBI). The benefits of using virtual reality in training for situations where safety is a factor have been established in defense and industry, but have not been demonstrated in rehabilitation.

SUBJECTS

Thirty subjects with TBI receiving comprehensive rehabilitation services at a residential facility.

METHODS

An immersive virtual kitchen was developed in which a meal preparation task involving multiple steps could be performed. The prototype was tested using subjects who completed the task twice within 7 days.

RESULTS

The stability of performance was estimated using intraclass correlation coefficients (ICCs). The ICC value for total performance based on all steps involved in the meal preparation task was .73. When three items with low variance were removed the ICC improved to .81. Little evidence of vestibular optical side-effects was noted in the subjects tested.

CONCLUSION

Adequate initial reliability exists to continue development of the environment as an assessment and training prototype for persons with brain injury.

Synthetic combined superoxide dismutase/catalase mimetics are protective as a delayed treatment in a rat stroke model: a key role for reactive oxygen species in ischemic brain injury

Stroke is a severe and prevalent syndrome for which there is a great need for treatment, including agents to block the cascade of brain injury that occurs in the hours after the onset of ischemia. Reactive oxygen species (ROS) have been implicated in this destructive process, but antioxidant enzymes such as superoxide dismutase (SOD) have been unsatisfactory in experimental stroke models. This study is an evaluation of the effectiveness of salen-manganese complexes, a class of synthetic SOD/catalase mimetics, in a rat focal ischemia model involving middle cerebral artery occlusion. We focus on EUK-134, a newly reported salen-manganese complex demonstrated here to have greater catalase and cytoprotective activities and equivalent SOD activity compared with the previously described prototype EUK-8. The administration of EUK-134 at 3 hr after middle cerebral artery occlusion significantly reduced brain infarct size, with the highest dose apparently preventing further infarct growth. EUK-8 was also protective but substantially less effective. These findings support a key role for ROS in the cascade of brain injury after stroke, even well after the onset of ischemia. The enhanced activity of EUK-134 suggests that, in particular, hydrogen peroxide contributes significantly to this injury. Overall, this study suggests that synthetic SOD/catalase mimetics might serve as novel, multifunctional therapeutic agents for stroke.

Alternating current electrocution detection and termination by an implantable cardioverter defibrillator

A patient with an ICD accidentally grasped a power line and was electrocuted. He was unable to release the cable during electrocution though he remained conscious. After receiving a shock from his ICD, the powerline was released. ICD interrogation revealed inappropriate detection of alternating current and delivery of a shock.

A lipidated anti-Tat antibody enters living cells and blocks HIV-1 viral replication

We have developed a chemical modification of antibodies, lipidation, which enables their intracellular delivery into living cells. Intracellular localization of lipidated antibodies was demonstrated by confocal microscopy and by measuring cellular uptake of 125I-labeled lipidated antibodies. Functionally, a lipidated monoclonal antibody directed against the Tat protein from human immunodeficiency virus type 1 (HIV-1) inhibited viral replication of several HIV-1 isolates by approximately 85% as shown by increased viability of infected cells and decreased reverse transcriptase activity. The antibody in its native form had no such effect. These data show that lipidated antibodies can reach and functionally inhibit intracellular targets. Lipidation may help to facilitate the development of intracellular immunotherapy for AIDS.

Potent inhibition of human immunodeficiency virus type 1 (HIV-1) replication by inducible expression of HIV-1 PR multimers

Constructs were generated in which expression of human immunodeficiency virus type 1 (HIV-1) protease (PR) was placed under control of the HIV-1 long terminal repeat, thus requiring the HIV-1 Tat protein for expression of PR. The activity of PR was assessed by cotransfection with a construct producing a Gag substrate. Expression of PR as an intramolecular multimer resulted in a large increase in PR activity in comparison with the level obtained with the expression of PR as a monomer. A cytotoxic effect of PR expression was also exhibited by the constructs expressing PR multimers. CD4+ T-cell lines were generated with a construct producing PR as a linked tetramer and screened for PR activity and inducibility. The replication of HIV-1 in these cell lines was several orders of magnitude reduced in comparison with that in cell lines not expressing PR. Infection in these cell lines could be detected early after infection but disappeared over time. Infection of the PR-expressing cell lines could be increased several orders of magnitude by the addition of a specific inhibitor of PR, U75875 (Upjohn), after infection of the cells, demonstrating that the potent inhibition of HIV-1 replication in these cells was directly due to the expression of PR.

The importance of being first: an analysis of tachistoscopic presentations of words

The importance of the first letter of a word as a cue for the rest of the word was explored in a tachistoscopic presentation of four letter English words to the two hemispheres. The positioning of words presented bilaterally and the frequency of the words were manipulated so that the role of the first letter could be examined. The results indicate that the first letter does not play the critical role in word recognition that has been ascribed to it. In the standard bilateral presentation, subjects' recall patterns indicated that first letters were recalled equally well whether the word was presented in the right or left visual field. However, subjects did not recall as many words correctly when they went to the left visual field. The results were interpreted as supporting an information processing view of hemispheric specialization. Such a view proposes several levels of functioning in which the two hemispheres overlap, cooperate, or specialize, depending on the task to be accomplished.