Prognostic Performance of Sequential Organ Failure Assessment, Acute Physiology and Chronic Health Evaluation III, and Simplified Acute Physiology Score II Scores in Patients with Suspected Infection According to Intensive Care Unit Type.

We investigated the prognostic performance of scoring systems by the intensive care unit (ICU) type. This was a retrospective observational study using data from the Marketplace for Medical Information in the Intensive Care IV database. The primary outcome was in-hospital mortality. We obtained Sequential Organ Failure Assessment (SOFA), Acute Physiology and Chronic Health Evaluation (APACHE) III, and Simplified Acute Physiology Score (SAPS) II scores in each ICU type. Prognostic performance was evaluated with the area under the receiver operating characteristic curve (AUROC) and was compared among ICU types. A total of 29,618 patients were analyzed, and the in-hospital mortality was 12.4%. The overall prognostic performance of APACHE III was significantly higher than those of SOFA and SAPS II (0.807, [95% confidence interval, 0.799-0.814], 0.785 [0.773-0.797], and 0.795 [0.787-0.811], respectively). The prognostic performance of SOFA, APACHE III, and SAPS II scores was significantly different between ICU types. The AUROC ranges of SOFA, APACHE III, and SAPS II were 0.723-0.826, 0.728-0.860, and 0.759-0.819, respectively. The neurosurgical and surgical ICUs had lower prognostic performance than other ICU types. The prognostic performance of scoring systems in patients with suspected infection is significantly different according to ICU type. APACHE III systems have the highest prediction performance. ICU type may be a significant factor in the prognostication.

A Knock-In Mouse Model of Thymoma With the GTF2I L424H Mutation.

INTRODUCTION: The pathogenesis of thymic epithelial tumors remains largely unknown. We previously identified GTF2I L424H as the most frequently recurrent mutation in thymic epithelial tumors. Nevertheless, the precise role of this mutation in tumorigenesis of thymic epithelial cells is unclear. METHODS: To investigate the role of GTF2I L424H mutation in thymic epithelial cells in vivo, we generated and characterized a mouse model in which the Gtf2i L424H mutation was conditionally knocked-in in the Foxn1+ thymic epithelial cells. Digital spatial profiling was performed on thymomas and normal thymic tissues with GeoMx-mouse whole transcriptome atlas. Immunohistochemistry staining was performed using both mouse tissues and human thymic epithelial tumors. RESULTS: We observed that the Gtf2i mutation impairs development of the thymic medulla and maturation of medullary thymic epithelial cells in young mice and causes tumor formation in the thymus of aged mice. Cell cycle-related pathways, such as E2F targets and MYC targets, are enriched in the tumor epithelial cells. Results of gene set variation assay analysis revealed that gene signatures of cortical thymic epithelial cells and thymic epithelial progenitor cells are also enriched in the thymomas of the knock-in mice, which mirrors the human counterparts in The Cancer Genome Atlas database. Immunohistochemistry results revealed similar expression pattern of epithelial cell markers between mouse and human thymomas. CONCLUSIONS: We have developed and characterized a novel thymoma mouse model. This study improves knowledge of the molecular drivers in thymic epithelial cells and provides a tool for further study of the biology of thymic epithelial tumors and for development of novel therapies.

Exploiting mesothelin in thymic carcinoma as a drug delivery target for anetumab ravtansine.

BACKGROUND: Thymic epithelial tumours (TETs) are rare tumours comprised of thymomas and thymic carcinoma. Novel therapies are needed, especially in thymic carcinoma where the 5-year survival rate hovers at 30%. Mesothelin (MSLN), a surface glycoprotein that is cleaved to produce mature MSLN (mMSLN) and megakaryocyte potentiating factor (MPF), is expressed in limited tissues. However, its expression is present in various cancers, including thymic carcinoma, where it is expressed in 79% of cases. METHODS: We utilised flow cytometry, in vitro cytotoxicity assays, and an in vivo xenograft model in order to demonstrate the ability of the MSLN targeting antibody-drug conjugate (ADC) anetumab ravtansine (ARav) in inhibiting the growth of thymic carcinoma. RESULTS: Thymoma and thymic carcinoma cell lines express MSLN, and anetumab, the antibody moiety of ARav, was capable of binding MSLN expressing thymic carcinoma cells and internalising. ARav was effective at inhibiting the growth of thymic carcinoma cells stably transfected with mMSLN in vitro. In vivo, 15 mg/kg ARav inhibited T1889 xenograft tumour growth, while combining 7.5 mg/kg ARav with 4 mg/kg cisplatin yielded an additive effect on inhibiting tumour growth. CONCLUSIONS: These data demonstrate that anetumab ravtansine inhibits the growth of MSLN positive thymic carcinoma cells in vitro and in vivo.

Simultaneous Expression of Long Non-Coding RNA FAL1 and Extracellular Matrix Protein 1 Defines Tumour Behaviour in Young Patients with Papillary Thyroid Cancer.

We investigated the regulatory mechanism of FAL1 and unravelled the molecular biological features of FAL1 upregulation in papillary thyroid cancer (PTC). Correlation analyses of FAL1 and neighbouring genes adjacent to chromosome 1q21.3 were performed. Focal amplification was performed using data from copy number alterations in The Cancer Genome Atlas (TCGA) database. To identify putative transcriptional factors, PROMO and the Encyclopaedia of DNA Elements (ENCODE) were used. To validate c-JUN and JUND as master transcription factors for FAL1 and ECM1, gene set enrichment analysis was performed according to FAL1 and ECM1 expression. Statistical analyses of the molecular biological features of FAL1- and ECM1-upregulated PTCs were conducted. FAL1 expression significantly correlated with that of neighbouring genes. Focal amplification of chromosome 1q21.3 was observed in ovarian cancer but not in thyroid carcinoma. However, PROMO suggested 53 transcription factors as putative common transcriptional factors for FAL1 and ECM1 simultaneously. Among them, we selected c-JUN and JUND as the best candidates based on ENCODE results. The expression of target genes of JUND simultaneously increased in FAL1- and ECM1-upregulated PTCs, especially in young patients. The molecular biological features represented RAS-driven PTC and simultaneously enriched immune-related gene sets. FAL1 and ECM1 expression frequently increased simultaneously and could be operated by JUND. The simultaneous upregulation might be a potential diagnostic and therapeutic target for RAS-driven PTC.

Acquired small cell lung cancer resistance to Chk1 inhibitors involves Wee1 up-regulation.

Platinum-based chemotherapy has been the cornerstone treatment for small cell lung cancer (SCLC) for decades, but no major progress has been made in the past 20 years with regard to overcoming chemoresistance. As the cell cycle checkpoint kinase 1 (Chk1) plays a key role in DNA damage response to chemotherapeutic drugs, we explored the mechanisms of acquired drug resistance to the Chk1 inhibitor prexasertib in SCLC. We established prexasertib resistance in two SCLC cell lines and found that DNA copy number, messengerRNA (mRNA) and protein levels of the cell cycle regulator Wee1 significantly correlate with the level of acquired resistance. Wee1 small interfering RNA (siRNA) or Wee1 inhibitor reversed prexasertib resistance, whereas Wee1 transfection induced prexasertib resistance in parental cells. Reverse phase protein microarray identified up-regulated proteins in the resistant cell lines that are involved in apoptosis, cell proliferation and cell cycle. Down-regulation of CDK1 and CDC25C kinases promoted acquired resistance in parental cells, whereas down-regulation of p38MAPK reversed the resistance. High Wee1 expression was significantly correlated with better prognosis of resected SCLC patients. Our results indicate that Wee1 overexpression plays an important role in acquired resistance to Chk1 inhibition. We also show that bypass activation of the p38MAPK signaling pathway may contribute to acquired resistance to Chk1 inhibition. The combination of Chk1 and Wee1 inhibitors may provide a new therapeutic strategy for the treatment of SCLC.

Downregulation of CYLD promotes IFN-γ mediated PD-L1 expression in thymic epithelial tumors.

OBJECTIVES: Recent genomic studies suggest the biological significance of the　cylindromatosis (CYLD) gene in thymic epithelial tumors (TETs). CYLD is a crucial regulator of immune response, and we previously reported that CYLD mutation is associated with high PD-L1 expression in thymic carcinoma. Therefore, we wanted to explore the role and mechanism of CYLD in regulating PD-L1 expression in TETs. MATERIALS AND METHODS: The role of CYLD in PD-L1 expression was assessed by knockdown of CYLD in TET cells upon stimulation with interferon gamma (IFN-γ), tumor necrosis factor-α (TNF-α) or polyinosinic-polycytidylic acid (poly I:C). The molecular mechanism was investigated through analysis of downstream molecules in the STAT1/IRF1 pathway. Moreover, the clinical correlation between low CYLD and high PD-L1 expression, and the clinical impact of CYLD expression were evaluated in tissue microarrays of 105 TET cases. RESULTS: CYLD knockdown significantly enhanced the expression of PD-L1 in presence of IFN-γ stimulation in most TET cell lines. However, this phenomenon was not observed in presence of TNF-α stimulation. CYLD knockdown upregulated IFN-γ mediated activation of the STAT1/IRF1 axis, which in turn induced PD-L1 expression. Interestingly, we found a significant association between low CYLD expression and ≥ 50 % PD-L1 expression (p = 0.001). In addition, the average proportion of tumor cells exhibiting PD-L1 staining was significantly higher in the low CYLD expression group (24.7 %) than in the high CYLD expression group (5.2 %) (p = 0.005). There was no correlation between CYLD expression and the frequency of pre-existing paraneoplastic auto-immune diseases. In advanced stages (III/IV), the low CYLD expressing group had numerically worse survival than the high CYLD group (log-rank p = 0.089). CONCLUSIONS: Our findings provide insight into the mechanism of regulation of PD-L1 expression by CYLD in TET cells. Tumors with low CYLD expression could be potential targets for PD-1/PD-L1 inhibitors.

Liver X Receptor ß Related to Tumor Progression and Ribosome Gene Expression in Papillary Thyroid Cancer.

BACKGROUND: Intracellular lipid deposition has been reported in thyroid glands in obese animal and human. To understand the regulatory mechanism of lipid metabolism in thyroid cancer, we investigated the expression status of liver X receptor (LXR) and analyzed its clinicopathological characteristics and molecular biological features. METHODS: Expression status of LXR and its transcriptional targets in human cancers were analyzed using The Cancer Genome Atlas (TCGA). The gene-sets related to high LXRß expression was investigated by gene set enrichment analysis (GSEA) using Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways and gene ontology biologic process. Quantitative reverse transcription polymerase chain reaction was performed in thyroid cancer samples using our validation cohort. RESULTS: In contrast to low expression of LXRα, LXRß was highly expressed in thyroid cancer compared to the other types of human cancers. High LXRß expression was correlated with the expression of LXRß transcriptional targets genes, such as apolipoprotein C1 (APOC1), APOC2, apolipoprotein E (APOE), ATP binding cassette subfamily G member 8 (ABCG8), sterol regulatory elementbinding protein 1c (SREBP1c), and SPOT14. Furthermore, High LXRß expression group indicated poor clinicopathological characteristics and aggressive molecular biological features independently from the drive mutation status. Mechanistically, high LXRß expression was coordinately related to ribosome-related gene sets. CONCLUSION: The mechanistic link between LXRß and ribosomal activity will be addressed to develop new diagnostic and therapeutic targets in thyroid cancers.

Shewanella insulae sp. nov., isolated from a tidal flat.

A Gram-stain-negative, aerobic, non-spore-forming, motile by single polar flagellum and ovoid or rod-shaped bacterial strain, designated JBTF-M18T, was isolated from tidal-flat sediment collected from the Yellow Sea, Republic of Korea. The neighbour-joining phylogenetic tree of 16S rRNA gene sequences showed that strain JBTF-M18T fell within the clade comprising the type strains of Shewanella species. Strain JBTF-M18T exhibited 16S rRNA gene sequence similarity values of 97.1-98.8 % to the type strains of S. loihica, S. aquimarina, S. waksmanii and S. marisflavi and of less than 96.9 % to the type strains of the other Shewanella species. The average nucleotide identity and digital DNA-DNA hybridization values between strain JBTF-M18T and the type strains of S. waksmanii and S. loihica were 72.0 and 89.5% and 18.9 and 38.1 %, respectively. DNA-DNA relatedness values between strain JBTF-M18T and the type strains of S. aquimarina and S. marisflavi were 14 and 19 %, respectively. The DNA G+C content of strain JBTF-M18T from genomic sequence data was 52.9 %. Strain JBTF-M18Tcontained MK-6 as the predominant menaquinone and Q-7 and Q-8 as the predominant ubiquinones. It had iso-C15 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 0 as the major fatty acids. The major polar lipids of strain JBTF-M18T were phosphatidylethanolamine and phosphatidylglycerol. Distinguished phenotypic properties, along with the phylogenetic and genetic distinctiveness, revealed that strain JBTF-M18T is separated from recognized Shewanella species. On the basis of the data presented, strain JBTF-M18T is considered to represent a novel species of the genus Shewanella, for which the name Shewanella insulae sp. nov. is proposed. The type strain is JBTF-M18T (=KACC 19869T=NBRC 113583T).

Serum CRIPTO does not confer drug resistance against osimertinib but is an indicator of tumor burden in non-small cell lung cancer.

BACKGROUND: Adenocarcinoma is the most common subtype of non-small cell lung cancer (NSCLC) and often harbors oncogenic driver mutations in the epidermal growth factor receptor (EGFR). Osimertinib (AZD9291), a third generation EGFR TKI, has replaced earlier generation EGFR TKIs for first line treatment of EGFR mutant lung cancer due to its improved overall survival, longer progression free survival, and better tolerability compared to earlier generation inhibitors. However, like earlier generation EGFR TKIs, only about two thirds of patients respond, indicating an unknown mechanism of intrinsic resistance for the non-responders. We previously identified overexpression of CRIPTO as a potential mechanism of intrinsic resistance to EGFR TKIs of first and second generation. OBJECTIVE: To determine if CRIPTO could promote drug resistance against the third generation EGFR-TKIs osimertinib. We also wanted to investigate whether this resistance was conferred by both membrane bound and secreted CRIPTO. Finally, we wanted to explore the potential of secreted CRIPTO as a non-invasive biomarker for EGFR-TKI resistance. MATERIALS AND METHODS: HCC827 and H1975, EGFR mutant non-small cell lung carcinoma (NSCLC) cell lines, were transfected with wildtype CRIPTO, two secreted variants of CRIPTO, a membrane only version of CRIPTO, and the mock backbone vector as the control. Western blotting, immunoprecipitation, and in vitro viability experiments were performed. In vivo work was carried out in athymic nude mice; 2 × 106 CRIPTO overexpressing HCC827 cells were implanted per mouse. EGFR mutant NSCLC patient blood samples were collected before treatment with and EGFR-TKI, during response while on treatment, and at progression while on treatment. RESULTS: Although both membrane bound and secreted CRIPTO forms were able to activate downstream pathways such as SRC, CRIPTO was unable to elicit resistance towards osimertinib in vitro or in vivo. CRIPTO serum levels in mice were higher in larger xenograft tumors. Furthermore, CRIPTO serum levels were higher in patients with progressing lung cancer when compared to their CRIPTO serum levels during EGFR-TKI response. CONCLUSIONS: CRIPTO does not cause resistance against third generation EGFR-TKI osimertinib. CRIPTO levels in serum might be a potentially useful biomarker for tumor burden in NSCLC patients.

Mutant GTF2I induces cell transformation and metabolic alterations in thymic epithelial cells.

The pathogenesis of thymic epithelial tumors (TETs) is poorly understood. Recently we reported the frequent occurrence of a missense mutation in the GTF2I gene in TETs and hypothesized that GTF2I mutation might contribute to thymic tumorigenesis. Expression of mutant TFII-I altered the transcriptome of normal thymic epithelial cells and upregulated several oncogenic genes. Gtf2i L424H knockin cells exhibited cell transformation, aneuploidy, and increase tumor growth and survival under glucose deprivation or DNA damage. Gtf2i mutation also increased the expression of several glycolytic enzymes, cyclooxygenase-2, and caused modifications of lipid metabolism. Elevated cyclooxygenase-2 expression by Gtf2i mutation was required for survival under metabolic stress and cellular transformation of thymic epithelial cells. Our findings identify GTF2I mutation as a new oncogenic driver that is responsible for transformation of thymic epithelial cells.

Gramella sabulilitoris sp. nov., isolated from a marine sand.

A Gram-stain-negative, aerobic, non-spore-forming, motile by gliding and rod-shaped bacterial strain, designated HSMS-1T, was isolated from a marine sand collected from the Yellow Sea, Republic of Korea, and identified by a polyphasic taxonomic approach. The neighbour-joining phylogenetic tree of 16S rRNA gene sequences showed that HSMS-1T fell within the clade comprising the type strains of species of the genus Gramella. HSMS-1T exhibited 16S rRNA gene sequence similarity values of 99.0 and 98.7 % to the type strains of Gramella echinicola and Gramella sediminilitoris and of 93.3-98.5 % to the type strains of the other species of the genus Gramella. The ANI and dDDH values between HSMS-1T and the type strains of G. echinicola, Gramella gaetbulicola, Gramella forsetii, Gramella salexigens, Gramella portivictoriae and Gramella flava were 72.6-79.3 % and 17.4-22.2 %, respectively. Mean DNA-DNA relatedness value between HSMS-1T and the type strain of G. sediminilitoris was 18 %. HSMS-1T contained MK-6 as the predominant menaquinone and iso-C15 : 0, anteiso-C15 : 0, iso-C17 : 0 3-OH and iso-C16 : 0 as the major fatty acids. The major polar lipid of HSMS-1T was phosphatidylethanolamine. The DNA G+C content of HSMS-1T from genomic sequence data was 39.2 %. Distinguishing phenotypic properties, along with the phylogenetic and genetic distinctiveness, revealed that HSMS-1T is separated from recognized species of the genus Gramella. On the basis of the data presented, strain HSMS-1T is considered to represent a novel species of the genus Gramella, for which the name Gramella sabulilitoris sp. nov. is proposed. The type strain is HSMS-1T(=KACC 19899T=NBRC 113648T).

Complete genome sequence of a novel reassortant H3N3 avian influenza virus.

Aquatic birds are known to be a reservoir for the most common influenza A viruses (IAVs). In the annual surveillance program, we collected the feces of migratory birds for the detection of IAVs in South Korea in November 2016. A novel reassorted H3N3 avian influenza virus (AIV) containing genes from viruses of wild and domestic birds was identified and named A/aquatic bird/South Korea/sw006/2016(H3N3). The polymerase basic 2 (PB2) and non-structural (NS) genes of this isolate are most closely related to those of wild-bird-origin AIV, while the polymerase basic 1 (PB1), polymerase acidic (PA), hemagglutinin (HA), nucleoprotein (NP), neuraminidase (NA), and matrix (M) genes are most closely related to those of domestic-bird-origin AIV. A/aquatic bird/South Korea/sw006/2016 contains PA, NP, M, and NS genes were most closely related to those of AIV subtype H4 and PB2, PB1, and HA genes that are most closely related to those of AIV subtype H3N8, while the NA gene was most closely related to those of subtype H10, which was recently detected in humans in China. These results suggest that novel reassortment of AIV strains occurred due to interaction between wild and domestic birds. Hence, we emphasize the need for continued surveillance of avian influenza virus in bird populations.

Sulfitobacter sabulilitoris sp. nov., isolated from marine sand.

A Gram-stain-negative, aerobic, non-motile and ovoid or rod-shaped bacterial strain, HSMS-29T, was isolated from a marine sand sample collected from the Yellow Sea, Republic of Korea. The neighbour-joining phylogenetic tree of 16S rRNA gene sequences showed that strain HSMS-29T fell within the clade comprising the type strains of Sulfitobacter species. Strain HSMS-29T exhibited 16S rRNA gene sequence similarities of 97.2-98.4 % to the type strains of Sulfitobacter mediterraneus, Sulfitobacter porphyrae, Sulfitobacter marinus, Sulfitobacter pontiacus, Sulfitobacter litoralis, Sulfitobacter brevis, Sulfitobacter noctilucicola and Sulfitobacter dubius and 96.3-96.9 % to the type strains of the other Sulfitobacter species. The genomic ANI values of strain HSMS-29T with the type strains of S. mediterraneus, S. marinus, S. pontiacus, S. litoralis, S. brevis, S. noctilucicola and S. dubius were 72.66-74.99 %. The DNA-DNA relatedness value between strain HSMS-29T and the type strain of S. porphyrae was 17 %. Strain HSMS-29T contained Q-10 as the predominant ubiquinone and C18 : 1 ω7c as the major fatty acid. The major polar lipids of strain HSMS-29T were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G+C content of strain HSMS-29T was 65.0 mol% (HPLC) or 64.4 % (genome analysis). Distinguished phenotypic properties, along with the phylogenetic and genetic distinctiveness, revealed that strain HSMS-29T is separated from recognized Sulfitobacter species. On the basis of the data presented here, strain HSMS-29T is considered to represent a novel species of the genus Sulfitobacter, for which the name Sulfitobactersabulilitoris sp. nov. is proposed. The type strain is HSMS-29T (=KACC 19870T=NBRC 113549T).

p38 Stabilizes Snail by Suppressing DYRK2-Mediated Phosphorylation That Is Required for GSK3ß-ßTrCP-Induced Snail Degradation.

Snail is a key regulator of epithelial-mesenchymal transition (EMT), which is a major step in tumor metastasis. Although the induction of Snail transcription precedes EMT, posttranslational regulation, especially phosphorylation of Snail, is critical for determining Snail protein levels or stability, subcellular localization, and the ability to induce EMT. To date, several kinases are known that enhance the stability of Snail by preventing its ubiquitination; however, the molecular mechanism(s) underlying this are still unclear. Here, we identified p38 MAPK as a crucial posttranslational regulator that enhances the stability of Snail. p38 directly phosphorylated Snail at Ser107, and this effectively suppressed DYRK2-mediated Ser104 phosphorylation, which is critical for GSK3ß-dependent Snail phosphorylation and ßTrCP-mediated Snail ubiquitination and degradation. Importantly, functional studies and analysis of clinical samples established a crucial role for the p38-Snail axis in regulating ovarian cancer EMT and metastasis. These results indicate the potential therapeutic value of targeting the p38-Snail axis in ovarian cancer. SIGNIFICANCE: These findings identify p38 MAPK as a novel regulator of Snail protein stability and potential therapeutic target in ovarian cancer.

Downregulation of CHIP promotes ovarian cancer metastasis by inducing Snail-mediated epithelial-mesenchymal transition.

The epithelial-mesenchymal transition (EMT) plays a pivotal role in the conversion of early-stage tumors into invasive malignancies. The transcription factor Snail, an extremely unstable protein whose subcellular levels are regulated by many E3 ubiquitin ligases, promotes EMT as well as associated pathological characteristics including migration, invasion, and metastasis. Through yeast two-hybrid screening, we identified the carboxyl terminus of Hsc70-interacting protein (CHIP) as a novel Snail ubiquitin ligase that interacts with Snail to induce ubiquitin-mediated proteasomal degradation. Inhibition of CHIP expression increases Snail protein levels, induces EMT, and enhances in vitro migration and invasion as well as in vivo metastasis of ovarian cancer cells. In turn, Snail depletion abrogates all phenomena induced by CHIP depletion. Finally, Snail and CHIP expression is inversely correlated in ovarian tumor tissues. These findings establish the CHIP-Snail axis as a post-translational mechanism of EMT and cancer metastasis regulation.

Checkpoint Kinase 1 Inhibition Enhances Cisplatin Cytotoxicity and Overcomes Cisplatin Resistance in SCLC by Promoting Mitotic Cell Death.

INTRODUCTION: Platinum-based chemotherapy remains the standard treatment for patients with SCLC, but the benefit of the treatment is often hampered by rapid development of drug resistance. Thus far, there is no targeted therapy available for SCLC. More than 90% of SCLC tumors harbor mutations in the tumor suppressor gene tumor protein p53 (p53), an important DNA damage checkpoint regulator, and these tumor cells rely predominantly on the checkpoint kinases to control DNA damage response. METHODS: We examined whether and how inhibition of checkpoint kinase 1 (Chk1) affects cisplatin cytotoxicity in SCLC cells with and without p53 mutations, and evaluated the effect of Chk1 inhibitor and cisplatin combination in cisplatin-sensitive and -resistant preclinical models. RESULTS: Inhibition of Chk1 synergized with cisplatin to induce mitotic cell death in the p53-deficeint SCLC cells. The effect was regulated in part through activation of caspase 2 and downregulation of E2F transcription factor 1 (E2F1). Furthermore, Chk1 inhibitors prexasertib and AZD7762 enhanced cisplatin antitumor activity and overcame cisplatin resistance in SCLC preclinical models in vitro an in vivo. We also observed that higher expression of Chk1 was associated with poorer overall survival of patients with SCLC. CONCLUSIONS: Our data account Chk1 as a potential therapeutic target in SCLC, and rationalize clinical development of Chk1 inhibitor and cisplatin combinational strategy for the treatment of SCLC.

Acquired SETD2 mutation and impaired CREB1 activation confer cisplatin resistance in metastatic non-small cell lung cancer.

Resistance to chemotherapy remains a critical barrier to effective cancer treatment. Although cisplatin is one of the most commonly used chemotherapeutic agents in the treatment of non-small cell lung cancer (NSCLC), mechanisms of resistance to this drug are not fully understood. Here, we report a novel cisplatin-resistance mechanism involving SET Domain Containing 2 (SETD2), a histone H3 lysine 36 (H3K36) trimethyltransferase, and cAMP-responsive element-binding protein 1 (CREB1). A549 cells selected in vivo to give brain metastases exhibited cisplatin resistance and decreased expression of phosphorylated CREB1. Next-generation sequencing (NGS) analysis identified a missense mutation in SETD2 (p.T1171K), and we demonstrated that SETD2-mediated trimethylation of H3K36 (H3K36me3) and CREB1 phosphorylation are critical for cellular sensitivity to cisplatin. Moreover, we showed that suppression of SETD2 or CREB1 and ectopic expression of mutant SETD2 conferred cisplatin resistance through inhibition of H3K36me3 and ERK activation in NSCLC cells. Our results provide evidence that SETD2 and CREB1 contribute to cisplatin cytotoxicity via regulation of the ERK signaling pathway, and their inactivation may lead to cisplatin resistance.

Dasatinib sensitises KRAS-mutant cancer cells to mitogen-activated protein kinase kinase inhibitor via inhibition of TAZ activity.

PURPOSE: Oncogenic KRAS mutations occur frequently in solid tumours, but no clinically applicable targeted strategy is yet available for treating human cancers with mutant KRAS. Here we aimed to identify a strategy for the treatment of KRAS-driven cancers. EXPERIMENTAL DESIGN: Cell viability and colony forming assays were used to assess the in vitro effect of dasatinib and trametinib as single agents or in combination. Western blot was used to analyse the phosphorylated protein and total protein levels. Xenograft models were used to evaluate the in vivo effect of drug combination on KRAS-driven tumour growth. RESULTS: Here, we report the discovery of a synergistic interaction between dasatinib (ABL and SRC family kinase inhibitor) and the mitogen-activated protein kinase kinase (MEK) inhibitor trametinib in KRAS-mutant cancer cells. We demonstrated that dasatinib enhanced the antitumour effect of trametinib against the KRAS-mutant cancer models both in vitro and in vivo, and the combination resulted in a significant reduction of cytoplasmic and nucleic TAZ protein level, and therefore decreased downstream protein levels of YAP/TAZ signalling pathway. Furthermore, direct knockdown of TAZ by small interfering RNA was able to increase the sensitivity of KRAS-mutant cells to trametinib treatment. CONCLUSION: These results indicate that dasatinib enhances the antitumour activity of MEK inhibitor through inhibition of TAZ activity and identify dasatinib and trametinib combination as a potential strategy for the treatment of KRAS-driven cancers.

Inhibition of AKT1 signaling promotes invasion and metastasis of non-small cell lung cancer cells with K-RAS or EGFR mutations.

Accumulating evidence supports a role of the PI3K-AKT pathway in the regulation of cell motility, invasion and metastasis. AKT activation is known to promote metastasis, however under certain circumstances, it also shows an inhibitory activity on metastatic processes, and the cause of such conflicting results is largely unclear. Here we found that AKT1 is an important regulator of metastasis and down-regulation of its activity is associated with increased metastatic potential of A549 cells. Inhibition of AKT1 enhanced migration and invasion in KRAS- or EGFR-mutant non-small cell lung cancer (NSCLC) cells. The allosteric AKT inhibitor MK-2206 promoted metastasis of KRAS-mutated A549 cells in vivo. We next identified that the phosphorylation of Myristoylated alanine-rich C-kinase substrate (MARCKS) and LAMC2 protein level were increased with AKT1 inhibition, and MARCKS or LAMC2 knockdown abrogated migration and invasion induced by AKT1 inhibition. This study unravels an anti-metastatic role of AKT1 in the NSCLC cells with KRAS or EGFR mutations, and establishes an AKT1-MARCKS-LAMC2 feedback loop in this regulation.

Effect of embedded shot on trace element concentrations in livers of Anseriformes species.

Trace elements were analyzed in the liver of white-fronted geese (Anser albifrons, n=15), mallards (Anas platyrhynchos, n=4) and spot-billed ducks (Anas poecilorhyncha, n=13) found dead in Gimpo, Korea. All mallards and eight spot-billed ducks had embedded lead shot. Embedded shot could be affected elevated trace element concentrations on geese and ducks. Element concentrations of cadmium (Cd), lead (Pb), chromium (Cr), aluminum (Al), copper (Cr), manganese (Mn) and zinc (Zn) differed among species and white-fronted geese without embedded shot had the lowest concentrations for all elements (geomean 0.36, 0.43, 0.07, 1.46, 7.60, 2.61 and 13.5µg/g dw, respectively). Cadmium in four (3.27-7.77µg/g dw) of 32 individuals and Pb in eight (5.07-9.72µg/g dw) of 32 individuals exceeded a tentative threshold effect level of Cd (>3.0µg/g dw) and Pb (>5.0µg/g dw) for birds; all geese and ducks for Cr (0.07-0.43µg/g dw) were within the background level (<4.0µg/g dw). All trace element concentrations were much greater in waterfowl species with embedded shot than without shot. Essential trace elements such as Cr, Al (geomean 1.46-37.3µg/g dw), Cu (7.60-57.1µg/g dw), Mn (2.61-27.6µg/g dw) and Zn (13.5-176µg/g dw) were within the normal range and were probably maintained by normal homeostatic mechanisms.