Distinct evolution of ST11 KL64 Klebsiella pneumoniae in Taiwan.

Carbapenem-resistant ST11_KL64 Klebsiella pneumoniae emerged as a significant public health concern in Taiwan, peaking between 2013 and 2015, with the majority of isolates exhibiting OXA-48 as the sole carbapenemase. In this study, we employed whole-genome sequencing to investigate the molecular underpinnings of ST11_KL64 isolates collected from 2013 to 2021. Phylogenomic analysis revealed a notable genetic divergence between the ST11_KL64 strains in Taiwan and those in China, suggesting an independent evolutionary trajectory. Our findings indicated that the ST11_KL64_Taiwan lineage originated from the ST11_KL64 lineage in Brazil, with recombination events leading to the integration of ICEKp11 and a 27-kb fragment at the tRNAASN sites, shaping its unique genomic landscape. To further elucidate this unique sublineage, we examined the plasmid contents. In contrast to ST11_KL64_Brazil strains, which predominantly carried blaKPC-2, ST11_KL64_Taiwan strains exhibited the acquisition of an epidemic blaOXA-48-carrying IncL plasmid. Additionally, ST11_KL64_Taiwan strains consistently harbored a multi-drug resistance IncC plasmid, along with a collection of gene clusters that conferred resistance to heavy metals and the phage shock protein system via various Inc-type plasmids. Although few, there were still rare ST11_KL64_Taiwan strains that have evolved into hypervirulent CRKP through the horizontal acquisition of pLVPK variants. Comprehensive characterization of the high-risk ST11_KL64 lineage in Taiwan not only sheds light on its epidemic success but also provides essential data for ongoing surveillance efforts aimed at tracking the spread and evolution of ST11_KL64 across different geographical regions. Understanding the molecular underpinnings of CRKP evolution is crucial for developing effective strategies to combat its emergence and dissemination.

Microevolution of CG23-I Hypervirulent Klebsiella pneumoniae during Recurrent Infections in a Single Patient.

CG23-I lineage constitutes the majority of hypervirulent Klebsiella pneumoniae. A diabetic patient suffered six episodes of infections caused by CG23-I K. pneumoniae. A total of nine isolates were collected in 2020. We performed whole-genome sequencing to elucidate the within-patient evolution of CG23-I K. pneumoniae. The maximum pairwise difference among the nine longitudinally collected isolates was five single nucleotide polymorphisms. One of the mutations was at the Asp87 position of GyrA. Four indels were identified, including an initiator tRNAfMet duplication, a tRNAArg deletion, a 7-bp insertion, and a 22-bp deletion. All 9 isolates had the genomic features of CG23-I K. pneumoniae, a chromosome-borne ICEKp10, and a large virulence plasmid. The carriage of a complete set of genes for the biosynthesis of colibactin by ICEKp10 gave the nine isolates an ability to cause DNA damage to RAW264.7 cells. Compared with the initial isolate, the last isolate with an additional copy of initiator tRNAfMet grew faster in a nutrient-limiting condition and exhibited enhanced virulence in BALB/c mice. Collectively, we characterized the within-patient microevolution of CG23-I K. pneumoniae through an in-depth comparison of genome sequences. Using the in vitro experiments and mouse models, we also demonstrated that these genomic alterations endowed the isolates with advantages to pass through in vivo selection. IMPORTANCE CG23-I is a significant lineage of hypervirulent Klebsiella pneumoniae. This study characterizes the within-patient microevolution of CG23-I K. pneumoniae. Selective pressures from continuous use of antibiotics favored point mutations contributing to bacterial resistance to antibiotics. The duplication of an initiator tRNAfMet gene helped CG23-I K. pneumoniae proliferate to reach a maximal population size during infections. For longer persistence inside a human host, the large virulence plasmid evolved with more flexible control of replication through duplication of the iteron-1 region. With the genomic alterations, the last isolate had a growth advantage over the initial isolate and exhibited enhanced virulence in BALB/c mice. This study gives us a deeper understanding of the genome evolution during the within-patient pathoadaptation of CG23-I K. pneumoniae.

Risk factors and prognoses of invasive Candida infection in surgical critical ill patients with perforated peptic ulcer.

BACKGROUND: The risk of invasive Candida infection (ICI) is high in patients with perforated peptic ulcer (PPU) who received laparotomy or laparoscopic surgery, but the risk factors and predictors of morbidity outcomes remain uncertain. This study aims to identify the risk factors of ICI in surgical critically ill PPU patients and to evaluate the impact on patient's outcomes. METHODS: This is a single-center, retrospective study, with a total of 170 surgical critically ill PPU patients. Thirty-seven patients were ICI present and 133 were ICI absent subjects. The differences in pulmonary complications according to invasive candidiasis were determined by the Mann-Whitney U test. Evaluation of predictors contributing to ICI and 90-day mortality was conducted by using multivariate logistic regression analysis. RESULTS: Candida albicans was the primary pathogen of ICI (74.29%). The infected patients had higher incidence of bacteremia (p < 0.001), longer intensive care unit (p < 0.001) and hospital (p < 0.001) stay, longer ventilator duration (p < 0.001) and increased hospital mortality (p = 0.02). In the multivariate analysis, serum lactate level measured at hospital admission was independently associated with the occurrence of ICI (p = 0.03). Liver cirrhosis (p = 0.03) and Sequential Organ Failure Assessment (SOFA) score (p = 0.007) were independently associated with the 90-day mortality. CONCLUSIONS: Blood lactate level measured at hospital admission could be a predictor of ICI and the surgical critically ill PPU patients with liver cirrhosis and higher SOFA score are associated with poor outcomes.

PD-L1 expressed from tumor cells promotes tumor growth and invasion in lung cancer via modulating TGF-ß1/SMAD4 expression.

BACKGROUND: Programmed death ligand-1 (PD-L1) has a known association with the prognosis of human cancers because of its ability to alter tumor immune surveillance via its interaction with PD-1. We questioned whether expression of PD-L1 in tumor cells could directly promote tumor growth and invasiveness in non-small cell lung cancer (NSCLC). METHODS: Real-time reverse transcription-polymerase chain reaction (RT-PCR) was performed to evaluate PD-L1 messenger RNA (mRNA) expression in lung tumors. The prognostic value of PD-L1 mRNA was assessed by Cox regression model. Transcriptional regulation of PD-L1 by human papillomavirus (HPV) 16/18 E6 oncoprotein or by epidermal growth factor receptor (EGFR) mutation in lung cancer cells was examined by Western blot and luciferase reporter assay. The cell growth and invasion were evaluated by colony formation, soft agar growth, and Boyden chamber assay. RESULTS: The PD-L1 mRNA levels showed a positive association with HPV 16/18 E6 oncoprotein and with EGFR mutation in 223 surgically resected NSCLC patients. The prognostic significance of PD-L1 was more commonly observed in patients with high PD-L1/E6 positive and high PD-L1/EGFR mutant tumors. Mechanistically, upregulation of PD-L1 transcription by E6 or mutant EGFR occurred largely through the ERK-C/EBPß-TLR4-NF-κB cascade. PD-L1 promotes the efficacy of colony formation, soft agar growth, and cell invasion. PD-L1 upregulates BAG-1 to reduce transforming growth factor (TGF)-ß1 expression, and the decrease in SMAD4 because of TGF-ß1 occurs through the p53/microRNA (miR)-224 axis. The decreases in TGF-ß1 and SMAD4 are responsible for PD-L1-mediated cell invasiveness. CONCLUSION: Induction of PD-L1 by E6 oncoprotein or mutant EGFR through the ERK-C/EBPß-TLR4-NF-κB cascade may promote tumor growth and invasiveness in NSCLC because of decreasing TGF-ß1 and SMAD4 expression.

Respiratory care for the critical patients with 2019 novel coronavirus.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted through respiratory droplets, aerosols and close contact. Cross infections occur because viruses spread rapidly among humans. Nineteen percent (19%) of the infected patients developed severe pneumonia and acute respiratory distress syndrome (ARDS). Hypoxemia usually occurs and patients may require oxygen therapy or mechanical ventilation (MV) support. In this article, recently published clinical experience and observational studies were reviewed. Corresponding respiratory therapy regarding different stages of infection is proposed. Infection control principles and respiratory strategies including oxygen therapy, non-invasive respiratory support (NIRS), intubation evaluation, equipment preparation, ventilator settings, special maneuvers comprise of the prone position (PP), recruitment maneuver (RM), extracorporeal membrane oxygenation (ECMO), weaning and extubation are summarized. Respiratory equipment and device disinfection recommendations are worked up. We expect this review article could be used as a reference by healthcare workers in patient care while minimizing the risk of environmental contamination.

Potential Impacts of Interleukin-17A Promoter Polymorphisms on the EGFR Mutation Status and Progression of Non-Small Cell Lung Cancer in Taiwan.

Non-small cell lung cancer (NSCLC) is a typical inflammation-associated cancer, and lung adenocarcinoma (LUAD) is the most common histopathological subtype. Epidermal growth factor receptor (EGFR) mutations are the most common driver mutations of LUAD, and they have been identified as important therapeutic targets by EGFR tyrosine kinase inhibitors. Interleukin (IL)-17A secreted by T-helper 17 lymphocytes is a proinflammatory cytokine that plays an important role in cancer pathogenesis. The present study was designed to investigate the possible associations among IL-17A genetic polymorphisms, EGFR mutation status, and the clinicopathologic development of LUAD in a Taiwanese population. Our study population consisted of 277 LUAD patients harboring the wild-type (WT) EGFR or a mutant (MT) EGFR. Four single-nucleotide polymorphisms (SNPs) of IL-17A in the peripheral blood, including rs8193036(C > T), rs8193037(G > A), rs2275913(G > A), and rs3748067(C > T) loci, were genotyped using a TaqMan allelic discrimination assay. Our results showed that none of these IL-17A SNPs were correlated with the risk of developing mutant EGFR. However, patients with a smoking habit who carried the GA genotype of IL-17A rs8193037 had a significantly lower susceptibility to EGFR mutations (adjusted odds ratio (AOR): 0.225; 95% confidence interval (CI): 0.056~0.900, p = 0.035). Moreover, compared to individuals carrying the CC genotype of rs8193036 at IL-17A, T-allele carriers (CT + TT) were at higher risk of developing more-advanced stages (stage III or IV; p = 0.020). In the WT EGFR subgroup analysis, IL-17A rs8193036 T-allele carriers had higher risks of developing an advanced tumor stage (p = 0.016) and lymphatic invasion (p = 0.049). Further analyses of clinical datasets revealed correlations of IL-17 receptor A (IL-17RA) and IL-17RC expressions with a poor prognosis of LUAD patients with a smoking history or with higher levels of tumor-infiltrating lymphocytes. In conclusion, our results suggested that two functional promoter polymorphisms of IL-17A, i.e., rs8193036 and rs8193037, were associated with the EGFR mutation status and progression in LUAD patients, indicating that these two genetic variants might act as possible markers for predicting patients' clinical prognoses.

The Relationship between Long Noncoding RNA H19 Polymorphism and the Epidermal Growth Factor Receptor Phenotypes on the Clinicopathological Characteristics of Lung Adenocarcinoma.

The aim of the current study is to investigate potential associations among Long Noncoding RNA (LncRNA) H19 single nucleotide polymorphism (SNP) and epidermal growth factor receptor (EGFR) phenotypes on the clinicopathological characteristics of lung adenocarcinoma (LADC). Five loci of LncRNA H19 SNPs (rs217727, rs2107425, rs2839698, rs3024270, and rs3741219) were genotyped by using TaqMan allelic discrimination in 223 LADC patients with wild-type EGFR phenotype and 323 LADC individuals with EGFR mutations. After the statistical analyses, patients with the EGFR mutation were related to a higher distribution frequency of rs217727 SNP CT heterozygote (p = 0.030), and the female population with EGFR mutation demonstrated a higher distribution frequency of rs217727 SNP CT heterozygote (p < 0.001) and rs2107425 CT heterozygote (p = 0.002). In addition, the presence of LncRNA H19 SNP rs217727 T allele (CT + TT) in patients with EGFR wild-type was associated to higher tumor T status (stage III or IV, p = 0.037) and poorer cell differentiation status (poor differentiation, p = 0.012) compared to those EGFR wild-type individuals with LncRNA H19 SNP rs217727 CC allele. Besides, a prominently higher tumor T status was found in subjects with LncRNA H19 SNP rs2107425 T allele (CT + TT) (stage III or IV, p = 0.007) compared to EGFR wild-type LADC individuals with LncRNA CC allele in EGFR wild-type patients. Our findings suggest that the presence of LncRNA H19 SNP rs217727 is related to the EGFR mutation in LADC patients, and the LncRNA H19 SNP rs217727 and rs2107425 are associated with progressed tumor status for LADC patients with EGFR wild-type.

Improved trends of lung cancer mortality-to-incidence ratios in countries with high healthcare expenditure.

BACKGROUND: Lung cancer stage has a significant impact on prognosis, and early detection of lung cancer relies on screenings. Despite the strong relationship between screening and lung cancer staging, the role of healthcare expenditure in lung cancer outcomes remains unknown. The aim of this study was to evaluate the relationship between economic status and clinical outcomes in lung cancer. METHODS: Data were obtained from GLOBOCAN and the World Health Organization. Mortality-to-incidence ratios (MIRs) and their change over time, calculated as the difference between the MIRs of 2012 and 2018 (δMIR), were used to evaluate their correlation to expenditures on healthcare and human development index (HDI) disparities via Spearman's rank correlation coefficient. RESULTS: Regions such as North America have relatively high crude incidence rates but low MIR values. Furthermore, countries with lower crude incidence rates spent less on healthcare. The results show significant negative associations between HDI, current health expenditure (CHE) per capita, CHE as a percentage of gross domestic product (CHE/GDP), and MIR. As for MIR and δMIR, countries with favorable MIRs also showed improving MIRs based on δMIR. CONCLUSIONS: HDI, CHE per capita, CHE/GDP, and development status play noticeable roles in the prognosis of lung cancer, leading to large disparities in clinical outcomes.

Massive Vespa basalis stings induce an envenoming syndrome.

Envenoming syndrome induced by massive Vespa basalis stings is a critical condition. Severe systemic reaction may present with hemolytic activity and rhabdomyolysis, leading diffuse alveolar hemorrhage, adult respiratory distress syndrome, coagulopathy, and multiple organs failure. In severe envenoming syndrome population, extracorporeal membrane oxygenation (ECMO) may be considered for unstable hemodynamic status. However, few studies reported ECMO in venom-induced disseminated intravascular coagulation patients. Here, we provide a case presented with pulmonary hemorrhage due to multiple Vespa basalis stings tried to rescue by veno-arterial extracorporeal membrane oxygenation. We also highlight that early recognition of venom-induced disseminated intravascular coagulation by checking coagulation profile in high risk patients may prevent from poor outcome.

Author Correction: PAK1 confers chemoresistance and poor outcome in non-small cell lung cancer via ß-catenin-mediated stemness.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Monocyte Chemoattractant Protein-1, a Possible Biomarker of Multiorgan Failure and Mortality in Ventilator-Associated Pneumonia.

Ventilator-associated pneumonia (VAP) leads to increased patients' mortality and medical expenditure. Monocyte chemoattractant protein-1 (MCP-1) plays a role in the pathogenesis of lung inflammation and infection. Therefore, the plasma concentration of MCP-1 was assessed and correlated with the clinical course in VAP patients. This retrospective observational study recruited 45 healthy volunteers, 12 non-VAP subjects, and 30 VAP patients. The diagnostic criteria for VAP were based on the American Thoracic Society guidelines, and the level of plasma MCP-1 was determined by ELISA. Plasma MCP-1 concentration was significantly elevated in the acute stage in VAP patients when compared with the control (p < 0.0001) and non-VAP patient groups (p = 0.0006). Subsequently, it was remarkably decreased following antibiotic treatment. Moreover, plasma MCP-1 concentration was positively correlated with indices of pulmonary dysfunction, including the lung injury score (p = 0.02) and the oxygenation index (p = 0.02). When patients with VAP developed adult respiratory distress syndrome (ARDS), their plasma MCP-1 concentrations were significantly higher than those of patients who did not develop ARDS (p = 0.04). Moreover, plasma MCP-1 concentration was highly correlated with organ failure scores, including simplified acute physiology score II (SAPS II, p < 0.0001), sequential organ failure assessment score (SOFA, p < 0.0001), organ dysfunctions and/or infection (ODIN, p < 0.0001), predisposition, insult response and organ dysfunction (PIRO, p = 0.005), and immunodeficiency, blood pressure, multilobular infiltrates on chest radiograph, platelets and hospitalization 10 days before onset of VAP (IBMP-10, p = 0.004). Our results demonstrate that plasma MCP-1 is an excellent marker for recognizing VAP when the cut-off level is set to 347.18 ng/mL (area under the curve (AUC) = 0.936, 95% CI = 0.863-0.977). In conclusion, MCP-1 not only could be a biological marker related to pulmonary dysfunction, organ failure, and mortality in patients with VAP, but also could be used for early recognition of VAP.

Association of nuclear localization of SHP2 and YAP1 with unfavorable prognosis in non-small cell lung cancer.

Src homology region 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2) is ubiquitously expressed in cytoplasmic localization, which in turn confers tumor malignancy and poor prognosis in various human cancers. YAP1 interacts with SHP2 to promote translocation of SHP2 to nucleus, which consequently promotes Wnt target activation. However, the oncogenic role of the nuclear localization of SHP2 in human cancers remains unclear. We hypothesized that nuclear SHP2 localization, in combination with nuclear YAP1 expression, could be associated with poor overall survival (OS) and relapse free survival (RFS) due to an increase in cyclin D1 and c-Myc mRNA expression following activation of Wnt/ß-catenin signaling. Immunohistochemical analysis of SHP2 and YAP1 protein expression in 102 tumors resected from patients with NSCLC revealed that nuclear SHP2 expression was well correlated with nuclear YAP1 expression (P < 0.001). Evaluation of cyclin D1 and c-Myc mRNA levels by the real-time reverse-phase polymerase chain reaction (RT-PCR) revealed that patients with high cyclin D1 and high c-Myc mRNA expressing tumors more commonly showed high nuclear YAP1 and high nuclear SHP2 (high/high) rather than the high/low, low/high, or low/low combinations (P < 0.001 for cyclin D1 and c-Myc). Kaplan-Meier and Cox-regression models showed OS and RFS to be poorer in patients in the high/high subgroup than in the low/low subgroup (OS: HR = 2.85, 95% CI, 1.52-5.35, P = 0.001; RFS: HR = 2.55, 95% CI, 1.37-4.72, P = 0.003). No prognostic significance was observed for the other two subgroups (low/high and high/low) when compared to the low/low subgroup in this study population. Therefore, we suggest that the prognostic value of SHP2 could reflect the nuclear localization of SHP2 and its interaction with nuclear YAP1, which led to subsequent upregulation of cyclin D1 and c-Myc mRNA expression via activation of the Wnt/ß-catenin signaling pathway.

Unfavorable Mortality-To-Incidence Ratio of Lung Cancer Is Associated with Health Care Disparity.

The mortality-to-incidence ratio (MIR) is associated with the clinical outcome of cancer treatment. For several cancers, countries with relatively good health care systems have favorable MIRs. However, the association between lung cancer MIR and health care expenditures or rankings has not been evaluated. We used linear regression to analyze the correlation between lung cancer MIRs and the total expenditures on health/gross domestic product (e/GDP) and the World Health Organization (WHO) rankings. We included 57 countries, for which data of adequate quality were available, and we found high rates of incidence and mortality but low MIRs in more developed regions. Among the continents, North America had the highest rates of incidence and mortality, whereas the highest MIRs were in Africa, Asia, Latin America, and the Caribbean. Globally, favorable MIRs correlated with high e/GDP and good WHO ranking (regression coefficient, -0.014 and 0.001; p = 0.004, and p = 0.014, respectively). In conclusion, the MIR for lung cancer in different countries varies with the expenditure on health care and health system rankings.

Clonal dissemination of carbapenemase-producing Klebsiella pneumoniae: Two distinct sub-lineages of Sequence Type 11 carrying blaKPC-2 and blaOXA-48.

OBJECTIVES: The global spread of carbapenem-resistant Klebsiella pneumoniae (CR-Kp) has become a massive threat to human health. We investigated the clonal relatedness of CR-Kp strains in central Taiwan. METHODS: CR-Kp strains were prospectively collected from inpatients referred to Chung Shan Medical University Hospital (CSMUH) during September 2011 to December 2015. The presence of carbapenemase genes, including blaKPC-2, blaVIM-1, blaNDM-1, and blaOXA-48, was analysed with polymerase chain reaction (PCR) and sequence determination. Clonal relatedness was determined by pulse-field gel electrophoresis and multilocus sequence typing. Capsule synthesis loci were typed based on the variation of the wzi gene. RESULTS: A total of 174 CR-Kp strains were collected. KPC-2 and OXA-48 were present in 63 (36.2%) and 22 (12.6%) CR-Kp strains, respectively. Two strains isolated in 2014 coproduced KPC-2 and OXA-48. Nearly all (98%) carbapenemase-producing K. pneumoniae strains belonged to the ST11 clone and could be further grouped into distinct sub-lineages. Intriguingly, the first sub-lineage, designated ST11-Clade I, contained all KPC-2 strains; OXA-48 strains were mostly included in the second sub-lineage, ST11-Clade II. Furthermore, a variation on the capsule synthesis loci was detected between these two sub-lineages: KL-47 was assigned to ST11-Clade I, whereas KL-64 or KL-9 were the main types for the ST11-Clade II strains. CONCLUSIONS: Clonal expansion of ST11 was responsible for the dissemination of carbapenemase-producing K. pneumoniae. Although KPC-2 still predominates, OXA-48 has emerged rapidly. Co-existence of KPC-2 and OXA-48 in two ST11-Clade I K. pneumoniae highlights the urgency to unravel mechanisms that contribute to this highly transmissible lineage.

A low microRNA-630 expression confers resistance to tyrosine kinase inhibitors in EGFR-mutated lung adenocarcinomas via miR-630/YAP1/ERK feedback loop.

Purpose: MicroRNA-630 plays dual roles in apoptosis and drug resistance in human cancers. However, the role of miR-630 in resistance to tyrosine kinase inhibitors (TKIs) in lung adenocarcinoma remains to be elucidated. Methods: Manipulation of miR-630 and its targeted gene YAP1 and/or combination of inhibitor treatments was performed to explore whether low miR-630 could confer TKI resistance due to de-targeting YAP1, and this could decrease proapoptotic protein Bad expression through the miR-630/YAP1/ERK feedback loop. A retrospective study was conducted to examine whether the expression of miR-630 and YAP1 could be associated with TKI therapeutic response in patients with lung adenocarcinoma. Results: Low miR-630 expression may confer TKI resistance via increased SP1 binding to the miR-630 promoter due to ERK activation by YAP1 de-targeting. Persistent activation of ERK signaling via the miR-630/YAP1/ERK feedback loop may be responsible for TKI resistance in EGFR-mutated cells. Moreover, a decrease in Bad expression by its phosphorylation at Serine 75 through ERK activation conferred low miR-630-mediated TKI resistance by modulating the apoptotic pathway. Xenographic tumors induced by miR-630-knockdown PC9 and PC9GR cells in nude mice were nearly suppressed by the combination of gefitinib with the YAP1 inhibitor verteporfin or an MEK/ERK inhibitor AZD6244. Patients with low miR-630 and high YAP1 expressing tumors had a higher prevalence of unfavorable responses to TKI therapy and poorer outcomes when compared with their counterparts. Conclusion: MiR-630 may be a potential biomarker for the prediction of TKI therapeutic response and outcome in patients with lung adenocarcinoma.

MicroRNA-630 may confer favorable cisplatin-based chemotherapy and clinical outcomes in non-small cell lung cancer by targeting Bcl-2.

MicroRNA-630 (miR-630) plays dual roles in tumor progression in various human cancers. However, the role of miR-630 in chemoresistance and prognosis in non-small cell lung cancer (NSCLC) remains to be elucidated. This retrospective study enrolled 114 surgically resected patients with NSCLC who experienced tumor relapse and underwent cisplatin-based chemotherapy. The aim was to examine the possible association between miR-630 (and its targeting of Bcl-2 expression) and the response to cisplatin-based chemotherapy. Patients with tumors expressing low miR-630, high Bcl-2, and a combination of both were more likely than their counterparts to show unfavorable responses to cisplatin-based chemotherapy. Kaplan-Meier and Cox regression analysis indicated that low miR-630, high Bcl-2, and a combination of both may independently predict poor overall survival and short relapse-free survival in patients with NSCLC. Six types of NSCLC cells were collected to determine the inhibitory concentration of cisplatin yielding 50% viability (IC50) by the MTT assay. The IC50 value for cisplatin was negatively correlated with miR-630 expression levels among these cell types, except for A549 cells. Mechanistically, low miR-630 expression conferred cisplatin resistance and colony formation by de-targeting Bcl-2 in NSCLC cells. We therefore suggest that low miR-630, high Bcl-2, and a combination of both may potentially predict an unfavorable chemotherapeutic response and poor outcome in patients with NSCLC.

PD-L1 confers resistance to EGFR mutation-independent tyrosine kinase inhibitors in non-small cell lung cancer via upregulation of YAP1 expression.

Programmed death ligand (PD-L1) expression was associated with tumor immune escape and subsequent poor prognosis in non-small cell lung cancer (NSCLC). This expression was higher in patients with EGFR-mutated NSCLC tumors than in those with EGFR-wild-type (WT) NSCLC tumors. We therefore hypothesized that poor prognosis mediated by higher PD-L1 may be partially through conferring resistance to tyrosine kinase inhibitor (TKI) in NSCLC regardless of EGFR mutation. The change in PD-L1 expression following gene manipulation corresponded with changes in expression of HIF-1α and YAP1. The expression of HIF-1α and YAP1 was concomitantly decreased by PD-L1 silencing or by ROS scavenger treatment (N-acetylcysteine, NAC); however, a ROS inducer treatment (pyocyanin) completely reversed the decreased expression of both genes in EGFR-mutated and -wild-type (WT) NSCLC cells. The MTT assay indicated that the inhibitory concentration of gefitinib yielding 50% cell viability (IC50) depended on PD-L1-mediated YAP1 expression. Mechanistic studies indicated that upregulation of YAP1 by PD-L1 might be responsible for EGFR mutation-independent TKI resistance via the ROS/HIF-1α axis. An unfavorable TKI response was more common in patient tumors with high PD-L1 or YAP1 mRNA expression than in patient tumors with low mRNA expression of these genes. In conclusion, PD-L1 might confer EGFR mutation-independent TKI resistance in NSCLC cells via upregulation of YAP1 expression.

Dioscin overcome TKI resistance in EGFR-mutated lung adenocarcinoma cells via down-regulation of tyrosine phosphatase SHP2 expression.

Resistance to tyrosine kinase inhibitors (TKIs) results in tumor relapse and poor prognosis in patients with lung adenocarcinoma. TKI resistance caused by epidermal growth factor receptor (EGFR) mutations at T790M and c-Met amplification occurs through persistent activation of the MEK/ERK and PI3K/AKT signaling pathways. We therefore expected that dual inhibitors of both signaling pathways could overcome TKI resistance in lung adenocarcinoma. Here, dioscin was selected from a product library of Chinese naturally occurring compounds and overcame TKI resistance in EGFR-mutated lung adenocarcinoma cells. Mechanistically, dioscin may down-regulate the expression of SH2 domain-containing phosphatase-2 (SHP2) at the transcription level by increasing p53 binding to the SHP2 promoter due to reactive oxygen species (ROS). Simultaneous inhibition of MEK/ERK and PI3K/AKT activation via decreased SHP2 expression and its interaction with GAB1 may be responsible for dioscin-mediated TKI sensitivity. A higher unfavorable response to TKI therapy occurred more commonly in patients with high SHP2 mRNA expression than in patients with low SHP2 mRNA expression. Therefore, we suggest that dioscin may act as a dual inhibitor of the MEK/ERK and PI3K/AKT signaling pathways to overcome TKI resistance via dysregulation of SHP2 expression in lung adenocarcinoma.