Small Cell Lung Cancer Cell Research Articles

The Synthetic Capsaicin‐analog Arvanil sensitizes Cisplatin‐Resistant Human Lung Cancer Cells to the pro‐apoptotic activity of Irinotecan

Cisplatin-based combination therapy is the standard of care for the treatment of human lung cancer. Initially, cisplatin shows excellent therapeutic response but the tumor inevitably relapses (within a year) and this relapsed tumor is resistant to cisplatin. A few human lung cancers do not respond to cisplatin-based first-line chemotherapy. These patients are said to have platinum-refractory lung tumors. Patients with platinum resistant or refractory disease have very limited options, as the only standard chemotherapy with an FDA-approved drug, irinotecan has an objective response rate of approximately 3% and little or no survival benefit. Therefore, agents which improve the therapeutic response (of human lung cancers) towards irinotecan may be useful for the treatment of cisplatin-resistant human lung cancer. The nutritional compound capsaicin sensitized cisplatin-resistant H69-CPR human small cell lung cancer (SCLC) cells towards irinotecan-induced apoptosis. Arvanil is a synthetic capsaicin-analog which displays enhanced growth-suppressive activity in human SCLC. The present study aims to investigate the combinatorial apoptotic activity of arvanil and irinotecan in cisplatin-resistant lung cancer. Caspase-3 activity assays reveal that the combination of irinotecan and arvanil displayed greater apoptotic activity in H69-CPR human cisplatin-resistant SCLC cells than the drugs used alone. These experiments were repeated in a second cisplatin-resistant lung cancer cell line PC9-CDDP and similar results were obtained. Chou-Talalay isobologram analysis showed the interaction between irinotecan and arvanil is synergistic in H69-CPR and PC9-CDDP cells. The combination of arvanil/irinotecan showed a greater synergistic pro-apoptotic activity than the combination of capsaicin/irinotecan. in H69-CPR and PC9-CDDP cells. The pro-apoptotic activity of arvanil/irinotecan was mediated elevation of intracellular calcium and required the calpain pathway. Taken together, our findings pave the way for the discovery of novel combination therapies for the therapy of cisplatin-resistant human lung cancer.

Synergy of HSP90 Inhibition and Radiation Therapy for cGAS/STING Pathway Activation

Even though immunotherapy is a common part in cancer treatment, only a small subset of patients profits long term. Since radiation therapy (RT) has been shown to improve tumor immunogenicity, treatment strategies combining RT and immunotherapy are an emerging field in cancer research. The inhibition of DNA damage repair (DDR) mechanisms is a potential target, because its impairment enhances, like RT alone, type-I interferon induction by activating the cGAS/STING pathway. Type-I interferons mediate the immunomodulatory effects following RT. Therefore, combination of RT and DDR inhibition appears to be a promising approach to enhance tumor immunogenicity. To induce broad DDR impairment, we here employ TAS-116 (Taiho Pharmaceutical Co., Ltd.), an inhibitor of Heat Shock Protein 90 (HSP90). First, we determined the tumor type-dependent toxicity by titering TAS-116 in six murine tumor cell lines and measured cell death via flow cytometry after 24h. Treatment with subtoxic concentrations of TAS-116 one hour prior to RT (up to 8Gy) resulted in increased γH2AX foci, indicating DNA damage, both in RP157.8 SCLC and B16F10 melanoma cells. Declining γH2AX foci were seen upon 12Gy in vitro. Our data suggest that irreparable DNA damage may occur which leads to cell death. The induction of DNA damage following TAS-116 treatment in combination with 8Gy RT was confirmed in vivo using a transplantable mouse tumor model. To confirm our hypothesis that the observed DNA damage mediates STING pathway activation in vitro, we performed Western blot analysis for pSTING at timepoints up to 72h after RT. While TAS-116 alone led to an increase up to 72h, highest pSTING levels were observed after 3h in combination with 8Gy RT, demonstrating synergistic effects for STING activation by accelerating and enhancing STING phosphorylation. While our results display an enhanced specific CD8+ T-cell-mediated killing in vitro using the transfected lymphoma cell line E.G7 after either treatment alone, combination of TAS-116 and RT up to 8Gy led to a significant reduction of this effect. We hypothesize that an observed upregulation of PD-L1 on the tumor cell surface, a known adverse effect of STING activation and suppressor of CD8+ T-cell-mediated killing, causes this phenomenon. Here, we demonstrate a synergy of HSP90 inhibition and RT to activate the immunogenic cGAS/STING pathway. However, to harness this effect therapeutically, anti-PD-1 therapy seems to be required.

Capsaicin enhances the pro‐apoptotic activity of Camptothecin in human small cell lung cancer

Small cell lung cancer (SCLC) accounts for 20% of all lung cancer cases and has a dismal five- year survival rate of less than 5%. Cisplatin-based combination chemotherapy (along with radiation) is the cornerstone of SCLC therapy. Initially, cisplatin shows excellent results causing remission in 60-80% of the SCLC patients but within a year the tumor inevitably relapses and this relapsed tumor is resistant to cisplatin and radiation. A subset of SCLC tumors does not respond to cisplatin from the outset. These patients are said to have platinum-refractory SCLC tumors. Patients with platinum resistant or refractory disease have very limited therapeutic options, as the only standard chemotherapy with an FDA-approved drug, camptothecin (and its derivations), has an objective response rate of approximately 3% and little or no survival benefit. Such sobering statistics define the arena where there is an urgent need for agents which enhance the pro-apoptotic activity of camptothecin in human SCLC. The present study tests the ability of capsaicin to sensitize human SCLC cells to the pro-apoptotic effects of camptothecin. Caspase-3 activity assays reveal that the combination of camptothecin and capsaicin displayed greater apoptotic activity than the drugs used alone. We verified these results using a second apoptosis assay, namely the Cell Death ELISA and obtained similar results. Chou-Talalay isobologram analysis showed the interaction between camptothecin and capsaicin is synergistic. Chicken chorioallantoic membrane (CAM) assays confirmed the combinatorial apoptotic effects of capsaicin and camptothecin in human SCLC. The co-operative effects of capsaicin and camptothecin were also confirmed in human SCLCs xenografted on athymic mice. The combinatorial growth-suppressive activity of camptothecin (in SCLCs) were mediated by elevation of intracellular calcium and the calpain pathway. Our findings pave the way foster the hope of novel combination drug regimens for the treatment of human small cell lung cancer.

Possible involvement of the Hedgehog and PDPK1-Akt pathways in the growth and migration of small-cell lung cancer.

BackgroundSmall-cell lung cancer (SCLC) accounts for approximately 15% to 20% of all lung cancers, and it is the leading cause of tumor-related deaths globally. This study explored the molecular mechanisms underlying the development of SCLC.MethodsThe correlations of phosphoinositide-dependent kinase-1 (PDPK1), p-Akt, and Hedgehog expression with patient characteristics were analyzed using SCLC specimens, and their expression was measured in BEAS-2B cells (control) and the SCLC cell lines H82, H69, H446, H146, and H526. Transfection experiments were performed to inhibit or activate gene expression in cells. We then measured the proliferation and migration of H146 cells.ResultsPDPK1, p-Akt, and Hedgehog expression was significantly higher in SCLC tissues, and their expression was correlated with patient characteristics. p-Akt expression was significantly correlated with Hedgehog expression. In H146 cells, PDPK1 and p-Akt were significantly upregulated. Silencing of PDPK1 or Akt and inhibition of Hedgehog significantly inhibited the proliferation and migration of H146 cells. PDPK1 and Akt affected Hedgehog expression, but Hedgehog did not affect PDPK1 or p-Akt expression.ConclusionsThe interaction between the PDPK1–Akt pathway and the Hedgehog pathway influences the prognosis, growth, and migration of SCLC.

PI3K/Akt/mTOR signaling orchestrates the phenotypic transition and chemo-resistance of small cell lung cancer

Small cell lung cancer (SCLC) is a phenotypically heterogeneous disease with an extremely poor prognosis, which is mainly attributed to the rapid development of resistance to chemotherapy. However, the relation between the growth phenotypes and chemo-resistance of SCLC remains largely unclear. Through comprehensive bioinformatic analyses, we found that the heterogeneity of SCLC phenotype was significantly associated with different sensitivity to chemotherapy. Adherent or semiadherent SCLC cells were enriched with activation of the PI3K/Akt/mTOR pathway and were highly chemoresistant. Mechanistically, activation of the PI3K/Akt/mTOR pathway promotes the phenotypic transition from suspension to adhesion growth pattern and confers SCLC cells with chemo-resistance. Such chemo-resistance could be largely overcome by combining chemotherapy with PI3K/Akt/mTOR pathway inhibitors. Our findings support that the PI3K/Akt/mTOR pathway plays an important role in SCLC phenotype transition and chemo-resistance, which holds important clinical implications for improving SCLC treatment.

MiR-574-5p mediates epithelial-mesenchymal transition in small cell lung cancer by targeting vimentin via a competitive endogenous RNA network.

Numerous studies have suggested that non-coding RNAs mediate tumorigenesis via the epithelial-mesenchymal transition (EMT). However, whether the long non-coding RNA (lncRNA) HOXA transcript at the distal tip (HOTTIP) plays a role in the EMT of small cell lung cancer (SCLC) remains unclear. The results of the present study suggest that HOTTIP-knockdown may lead to a significant increase in E-cadherin expression and a decrease in vimentin (VIM) expression; these proteins are two key markers of EMT. Furthermore, a notable morphological change in SCLC cells with HOTTIP-knockdown was observed: After upregulation of microRNA (miR)-574-5p, the cells exhibited a long, fusiform morphology. Investigating these phenomena further revealed that HOTTIP may participate in EMT by binding to miR-574-5p. In addition, using bioinformatics technology and a dual luciferase reporter assay, it was found that miR-574-5p inhibited VIM expression via direct binding and interaction. In summary, the present results indicate that HOTTIP may be involved in the EMT of SCLC by binding to miR-574-5p, and that miR-574-5p may act through VIM, which is a key marker of EMT.

Beyond Programmed Death-Ligand 1: B7-H6 Emerges as a Potential Immunotherapy Target in SCLC

IntroductionThe programmed death-ligand 1 (PD-L1) immune checkpoint inhibitors, atezolizumab and durvalumab, have received regulatory approval for the first-line treatment of patients with extensive-stage SCLC. Nevertheless, when used in combination with platinum-based chemotherapy, these PD-L1 inhibitors only improve overall survival by 2 to 3 months. This may be due to the observation that less than 20% of SCLC tumors express PD-L1 at greater than 1%. Evaluating the composition and abundance of checkpoint molecules in SCLC may identify molecules beyond PD-L1 that are amenable to therapeutic targeting. MethodsWe analyzed RNA-sequencing data from SCLC cell lines (n = 108) and primary tumor specimens (n = 81) for expression of 39 functionally validated inhibitory checkpoint ligands. Furthermore, we generated tissue microarrays containing SCLC cell lines and patient with SCLC specimens to confirm expression of these molecules by immunohistochemistry. We annotated patient outcomes data, including treatment response and overall survival. ResultsThe checkpoint protein B7-H6 (NCR3LG1) exhibited increased protein expression relative to PD-L1 in cell lines and tumors (p < 0.05). Higher B7-H6 protein expression correlated with longer progression-free survival (p = 0.0368) and increased total immune infiltrates (CD45+) in patients. Furthermore, increased B7-H6 gene expression in SCLC tumors correlated with a decreased activated natural killer cell gene signature, suggesting a complex interplay between B7-H6 expression and immune signature in SCLC. ConclusionsWe investigated 39 inhibitory checkpoint molecules in SCLC and found that B7-H6 is highly expressed and associated with progression-free survival. In addition, 26 of 39 immune checkpoint proteins in SCLC tumors were more abundantly expressed than PD-L1, indicating an urgent need to investigate additional checkpoint targets for therapy in addition to PD-L1.

Molecular Signature of Small Cell Lung Cancer after Treatment Failure: The MCM Complex as Therapeutic Target.

Simple SummarySmall cell lung cancer (SCLC) is a fatal malignant tumor with a poor prognosis for patients who relapse after first-line treatment. There are few effective treatments for SCLC patients with relapse. Elucidation of the molecular network related to treatment resistance is an important issue for this disease. In this study, the molecular signature of SCLC specimens after treatment failure was generated. Several pathways, e.g., “cell cycle”, “homologous recombination”, “DNA replication”, and “p53 signaling” were identified as the enriched pathways in this signature. Aberrant expression of MCM2, MCM4, MCM6, and MCM7 were detected in SCLC clinical specimens after treatment failure. This signature contains molecules involved in treatment resistance and will contribute to the study of SCLC molecular pathogenesis.Small cell lung cancer (SCLC) is a highly aggressive cancer, and patients who become refractory to first-line treatment have a poor prognosis. The development of effective treatment regimens is urgently needed. In this study, we identified a gene expression signature of SCLC after treatment failure using SCLC clinical specimens (GEO accession number: GSE162102). A total of 1,136 genes were significantly upregulated in SCLC tissues. These upregulated genes were subjected to KEGG pathway analysis, and “cell cycle”, “Fanconi anemia”, “alcoholism”, “systemic lupus erythematosus”, “oocyte meiosis”, “homologous recombination”, “DNA replication”, and “p53 signaling” were identified as the enriched pathways among the genes. We focused on the cell cycle pathway and investigated the clinical significance of four genes associated with this pathway: minichromosome maintenance (MCM) 2, MCM4, MCM6, and MCM7. The overexpression of these MCM genes was confirmed in SCLC clinical specimens. Knockdown assays using siRNAs targeting each of these four MCM genes showed significant attenuation of cancer cell proliferation. Moreover, siRNA-mediated knockdown of each MCM gene enhanced the cisplatin sensitivity of SCLC cells. Our SCLC molecular signature based on SCLC clinical specimens after treatment failure will provide useful information to identify novel molecular targets for this disease.

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.

Inhibition of lncRNA KCNQ1OT1 Improves Apoptosis and Chemotherapy Drug Response in Small Cell Lung Cancer by TGF-β1 Mediated Epithelial-to-Mesenchymal Transition.

PurposeDrug resistance is one of the main causes of chemotherapy failure in patients with small cell lung cancer (SCLC), and extensive biological studies into chemotherapy drug resistance are required.Materials and MethodsIn this study, we performed lncRNA microarray, in vitro functional assays, in vivo models and cDNA microarray to evaluate the impact of lncRNA in SCLC chemoresistance.ResultsThe results showed that KCNQ1OT1 expression was upregulated in SCLC tissues and was a poor prognostic factor for patients with SCLC. Knockdown of KCNQ1OT1 inhibited cell proliferation, migration, chemoresistance and promoted apoptosis of SCLC cells. Mechanistic investigation showed that KCNQ1OT1 can activate transforming growth factor-β1 mediated epithelial-to-mesenchymal transition in SCLC cells.ConclusionTaken together, our study revealed the role of KCNQ1OT1 in the progression and chemoresistance of SCLC, and suggested KCNQ1OT1 as a potential diagnostic and prognostic biomarker in SCLC clinical management.

Aberrant methylation modifications reflect specific drug responses in small cell lung cancer

In the study, Methylated DNA immunoprecipitation sequencing, RNA sequencing, and whole-exome sequencing were employed to clinical small cell lung cancer (SCLC) patients. Then, we verified the therapeutic predictive effects of differentially methylated genes (DMGs) in 62 SCLC cell lines. Of 4552 DMGs between chemo-sensitive and chemo-insensitive group, coding genes constituted the largest percentage (85.08%), followed by lncRNAs (10.52%) and miRNAs (3.56%). Both two groups demonstrated two methylation peaks near transcription start site and transcription end site. Two lncRNA-miRNA-mRNA networks suggested the extensive genome connection between chemotherapy efficacy-related non-coding RNAs (ncRNAs) and mRNAs. Combing miRNAs and lncRNAs could effectively predict chemotherapy response in SCLC. In addition, we also verified the predictive values of mutated genes in SCLC cell lines. This study was the first to evaluate multiple drugs efficacy-related ncRNAs and mRNAs which were modified by methylation in SCLC. DMGs identified in our research might serve as promising therapeutic targets to reverse drugs-insensitivity by complex lncRNA-miRNA-mRNA mechanisms in SCLC.

P15.01 AMG 757, a Half-Life Extended Bispecific T-Cell Engager (HLE BiTE® Immune Therapy) Targeting DLL3, for the Treatment of Small Cell Lung Cancer

Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumor characterized by initial response to chemotherapy and radiotherapy followed by relapse and rapid progression. Delta-like ligand 3 (DLL3) is an inhibitory Notch ligand that is highly expressed on the surface of most SCLC tumors; DLL3 expression is minimal and mainly cytoplasmic in normal tissues. AMG 757 is an investigational HLE BiTE immune therapy designed to redirect cytotoxic T cells to SCLC cells by binding to DLL3 on tumor cells and CD3 on T cells, resulting in T-cell activation and expansion and T cell–dependent killing of tumor cells.

AMG 757, a Half-Life Extended, DLL3-Targeted Bispecific T-Cell Engager, Shows High Potency and Sensitivity in Preclinical Models of Small-Cell Lung Cancer.

Small-cell lung cancer (SCLC) is an aggressive neuroendocrine tumor with a high relapse rate, limited therapeutic options, and poor prognosis. We investigated the antitumor activity of AMG 757, a half-life extended bispecific T-cell engager molecule targeting delta-like ligand 3 (DLL3)-a target that is selectively expressed in SCLC tumors, but with minimal normal tissue expression. AMG 757 efficacy was evaluated in SCLC cell lines and in orthotopic and patient-derived xenograft (PDX) mouse SCLC models. Following AMG 757 administration, changes in tumor volume, pharmacodynamic changes in tumor-infiltrating T cells (TILs), and the spatial relationship between the appearance of TILs and tumor histology were examined. Tolerability was assessed in nonhuman primates (NHPs). AMG 757 showed potent and specific killing of even those SCLC cell lines with very low DLL3 expression (<1,000 molecules per cell). AMG 757 effectively engaged systemically administered human T cells, induced T-cell activation, and redirected T cells to lyse tumor cells to promote significant tumor regression and complete responses in PDX models of SCLC and in orthotopic models of established primary lung SCLC and metastatic liver lesions. AMG 757 was well tolerated with no AMG 757-related adverse findings up to the highest tested dose (4.5 mg/kg weekly) in NHP. AMG 757 exhibits an extended half-life in NHP, which is projected to enable intermittent administration in patients. AMG 757 has a compelling safety and efficacy profile in preclinical studies making it a viable option for targeting DLL3-expressing SCLC tumors in the clinical setting.

FK228 sensitizes radioresistant small cell lung cancer cells to radiation

BackgroundConcurrent thoracic radiation plus chemotherapy is the mainstay of first-line treatment for limited-stage small cell lung cancer (LS-SCLC). Despite initial high responsiveness to combined chemo- and radiotherapy, SCLC almost invariably relapses and develops resistance within one year, leading to poor prognosis in patients with LS-SCLC. Developing new chemical agents that increase ionizing radiation’s cytotoxicity against SCLC is urgently needed.ResultsDual histone deacetylase (HDAC) and PI3K inhibitor FK228 not only displayed potent anticancer activity, but also enhanced the therapeutic effects of radiotherapy in SCLC cells. Mechanistically, radioresistant SCLC cells exhibit a lower level of histone H3K9 acetylation and a higher expression level of the MRE11-RAD50-NBS1 (MRN) complex and show more efficient and redundant DNA damage repair capacities than radiosensitive SCLC cells. FK228 pretreatment resulted in marked induction of H3k9 acetylation, attenuated homologous recombination (HR) repair competency and impaired non-homologous end joining (NHEJ) repair efficacy, leading to the accumulation of radiation-induced DNA damage and radiosensitization.ConclusionThe study uncovered that FK228 sensitized human radioresistant SCLC cells to radiation mainly through induction of chromatin decondensation and suppression of DNA damage signaling and repair. Our study provides a rational basis for a further clinical study to test the potential of FK228 as a radiosensitizing agent to increase the radiation-induced tumor cell kill in LS-SCLC patients.

Neuron specific enolase promotes tumor metastasis by activating the Wnt/β-catenin pathway in small cell lung cancer

Neuron-specific enolase (NSE) has been used as a specific biomarker for small cell lung cancer (SCLC) patients. Nevertheless, the biological function and mechanism of NSE in SCLC are still unclear. In this study, we clarified the role of NSE in the progression of SCLC and found that NSE expression was positively correlated with distant metastasis. Functional analysis showed that overexpression of NSE promoted migration and invasion of SCLC cells. Mechanism analysis showed that NSE overexpression induced epithelial-mesenchymal transition (EMT) of SCLC cells. Moreover, overexpression of NSE increased the protein expression of β-catenin and its downstream target genes, and silencing β-catenin eliminated NSE-mediated cell migration, invasion and EMT process. Furthermore, NSE interacted with β-catenin and inhibited the degradation of β-catenin. Besides, the animal experiments also indicated that NSE could promote the EMT process and distant metastasis of SCLC cells in vivo. In summary, our results revealed that NSE could promote the EMT process of SCLC cells by activating the Wnt/β-catenin signaling pathway, thereby promoting cell migration, invasion and distant metastasis, which might serve as a potential target for the therapy of SCLC patients.

High-Sensitive Detection of Small-Cell Lung Cancer Cells Based on Terminal Deoxynucleotidyl Transferase-Mediated Extension Polymerization Aptamer Probe.

Small-cell lung cancer (SCLC) is characterized by early metastasis and high invasiveness, poor prognosis, and a low five-year survival rate. Therefore, the development of the effective detection of SCLC cells and imaging methods has potential significance for the prognosis and treatment of SCLC. We designed a terminal deoxynucleotidyl transferase (TdT)-mediated extension polymerization aptamer probe (denoted as TEPAP). Aptamer HCC03 was used as an element of recognizing SCLC, and it was extended as a long poly(T) tail at the 3'-hydroxyl terminus by TdT and then hybridized with short poly(A) labeled with 6-carboxyfluorescein (FAM) to construct TEPAP for the high-sensitivity detection of SCLC. The results showed that the probe could specifically recognize NCI-H446 cells. Compared with HCC03 labeled with FAM, TEPAP has demonstrated a higher fluorescence signal in recognizing NCI-H446 cells, and the fluorescence intensity of TEPAP recognizing the target cells was 10 times higher than that of nontarget cells. Flow cytometric analysis showed that the detection limit of this method was as low as 17 NCI-H446 cells in 200 μL of binding buffer. In the application of clinical cytology cell blocks, the sensitivity, specificity, and accuracy of TEPAP were 89.74, 94.44, and 91.23%, respectively. The high sensitivity and specificity of TEPAP in the application of clinical samples show that the proposed probe has great potential in the diagnosis of SCLC.

Comprehensive genomic profiling of combined small cell lung cancer.

BackgroundCombined small cell lung cancer (CSCLC) is an uncommon and heterogeneous subtype of small cell lung cancer (SCLC). However, there is limited data concerning the different molecular changes and clinical features in CSCLC compared to pure SCLC.MethodsThe clinical and pathological characteristics of pure SCLC and CSCLC patients were analyzed. Immunohistochemistry and microdissection were performed to isolate the CSCLC components. Further molecular analysis was carried out by next-generation sequencing (NGS) in 12 CSCLC and 30 pure SCLC.ResultsThere were no significant differences in clinical features between CSCLC and pure SCLC. Overall survival (OS) of CSCLC patients was worse than pure SCLC (P=0.005). NGS results indicated that TP53 and RB1 were the most frequently mutated genes in both CSCLC (83.33% and 66.67%) and pure SCLC (80.00% and 63.33%) groups. However, less than 10% common mutations were found in both CSCLC and pure SCLC. When analyzing the data of SCLC and non-small cell lung cancer (NSCLC) components of CSCLC, more than 50% common mutations, and identical genes with mutations were detected. Moreover, there were also common biological processes and signaling pathways identified in CSCLC and pure SCLC, in addition to SCLC and NSCLC components.ConclusionsThere were no significant differences in terms of clinical features between CSCLC and pure SCLC. However, the prognosis for CSCLC was worse than pure SCLC. NGS analysis suggested that CSCLC components might derive from the same pluripotent single clone with common initial molecular alterations and subsequent acquisitions of other genetic mutations.

Medical costs of Japanese lung cancer patients during end-of-life care.

The medical costs associated with cancer treatment have increased rapidly in Japan; however, little data exist on actual costs, especially for end-of-life care. Therefore, this study aimed to examine the medical costs of lung cancer patients during the last 3 months before death and to compare the costs with those of initial anticancer treatment. We retrospectively evaluated all patients who died from lung cancer at the Japanese Red Cross Medical Center between 1 January 2008 and 31 August 2019. Patients were classified into three cohorts (2008-2011, 2012-2015 and 2016-2019) according to the year of death; the medical costs were evaluated for each cohort. Costs were then divided into outpatient and inpatient costs and calculated per month. Seventy-nine small cell lung cancer and 213 non-small cell lung cancer patients were included. For small cell lung cancer and non-small cell lung cancer patients, most end-of-life medical costs were inpatient costs across all cohorts. The median monthly medical costs for the last 3 months among both small cell lung cancer and non-small cell lung cancer patients did not differ significantly among the cohorts, but the mean monthly costs for non-small cell lung cancer tended to increase. The monthly medical costs for the last 3 months were significantly higher than those for the first year in SCLC (P=0.013) and non-small cell lung cancer (P<0.001) patients and those for the first 3 months in non-small cell lung cancer patients (P=0.005). The medical costs during the end-of-life period for lung cancer were high and surpassed those for initial treatment.

Bufadienolides and ecdysteroids from the whole plants of Helleborus niger and their cytotoxicity

A new bufadienolide (1), two new bufadienolide glycosides (2 and 3), a new ecdysteroid (4), and four known compounds (5-8), were isolated from the whole plants of Helleborus niger L. (Ranunculaceae). The structures of the new compounds (1-4) were determined by spectroscopic analysis, including 2D NMR spectral data, and hydrolytic studies. Compounds 1-6 showed cytotoxicity against HL-60 human leukemia cells, A549 human lung adenocarcinoma cells, and SBC-3 human small-cell lung cancer cells, with IC50 values ranging from 0.0055 to 1.9µM. HL-60 cells treated with either 3 or 4 showed apoptosis characteristics, such as nuclear chromatin condensation, accumulation of sub-G1 cells, and activation of caspase-3/7.

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.