Synergistic cytotoxicity of the CDK4 inhibitor Fascaplysin in combination with EGFR inhibitor Afatinib against Non-small Cell Lung Cancer.

In the absence of suitable molecular markers, non-small cell lung cancer (NSCLC) patients have to be treated with chemotherapy with poor results at advanced stages. Therefore, the activity of the anticancer marine drug fascaplysin was tested against primary NSCLC cell lines established from pleural effusions. Cytotoxicity of the drug or combinations were determined using MTT assays and changes in intracellular phosphorylation by Western blot arrays. Fascaplysin revealed high cytotoxicity against NSCLC cells and exhibit an activity pattern different of the standard drug cisplatin. Furthermore, fascaplysin synergizes with the EGFR tyrosine kinase inhibitor (TKI) afatinib to yield a twofold increased antitumor effect. Interaction with the Chk1/2 inhibitor AZD7762 confirm the differential effects of fascplysin and cisplatin. Protein phosphorylation assays showed hypophosphorylation of Akt1/2/3 and ERK1/2 as well as hyperphosphorylation of stress response mediators of H1299 NSCLC cells. In conclusion, fascaplysin shows high cytotoxicity against pleural primary NSCLC lines that could be further boosted when combined with the EGFR TKI afatinib.

Rovalpituzumab tesirine resistance: analysis of a corresponding small cell lung cancer and circulating tumor cell line pair.

Small cell lung cancer (SCLC) is frequently found disseminated at first presentation and holds a poor prognosis due to emerging resistance to first-line platinum-based and second-line topotecan chemotherapy. The present investigation tested the antitumor activity of rovalpituzumab tesirine (ROVA-T), a cytotoxic anti-DLL3 drug conjugate, against two SCLC and a corresponding SCLC CTC cell line established from a ROVA-T-resistant patient to characterize the mechanism of recurrence. Two cell lines were established from an SCLC patient progressing under ROVA-T therapy and characterized with respect to chemosensitivity against this drug as well as against currently applied chemotherapeutics and for their delta-like 3 (DLL3) expression. The chemosensitivity assays demonstrate that most SCLC lines show IC50 values exceeding the ROVA-T in-vivo concentrations and that slow-growing cells and lines showing spheroidal growth or proliferation as corresponding circulating tumor cells (CTCs) exhibit higher resistance. Chemosensitivity of the cell lines is not correlated with DLL3 protein expression possibly due to toxicity of the free payload in tissue culture. The clinical trials and experimental results demonstrate that refractoriness to ROVA-T is linked to a low initial tumor expression of DLL3, loss of DLL3 expression, higher chemoresistance to ROVA-T and the putative formation of resistant spheroids by the SCLC cells.

53BP1/RIF1 signaling promotes cell survival after multifractionated radiotherapy.

Multifractionated irradiation is the mainstay of radiation treatment in cancer therapy. Yet, little is known about the cellular DNA repair processes that take place between radiation fractions, even though understanding the molecular mechanisms promoting cancer cell recovery and survival could improve patient outcome and identify new avenues for targeted intervention. To address this knowledge gap, we systematically characterized how cells respond differentially to multifractionated and single-dose radiotherapy, using a combination of genetics-based and functional approaches. We found that both cancer cells and normal fibroblasts exhibited enhanced survival after multifractionated irradiation compared with an equivalent single dose of irradiation, and this effect was entirely dependent on 53BP1-mediated NHEJ. Furthermore, we identified RIF1 as the critical effector of 53BP1. Inhibiting 53BP1 recruitment to damaged chromatin completely abolished the survival advantage after multifractionated irradiation and could not be reversed by suppressing excessive end resection. Analysis of the TCGA database revealed lower expression of 53BP1 pathway genes in prostate cancer, suggesting that multifractionated radiotherapy might be a favorable option for radio-oncologic treatment in this tumor type. We propose that elucidation of DNA repair mechanisms elicited by different irradiation dosing regimens could improve radiotherapy selection for the individual patient and maximize the efficacy of radiotherapy.

Interactions of BRCA1-mutated Breast Cancer Cell Lines with Adipose-derived Stromal Cells (ADSCs).

Lipofilling may constitute a technique to assist reconstruction of breasts following prophylactic mastectomy for patients with mutated BRCA1 or BRCA2 genes. However, to date it is not clear whether adipose-derived stromal cells (ADSCs) increase the risk of tumor initiation and progression in this situation. Therefore, the interactions of BRCA1 mutated breast cancer cell lines with normal ADSCs were investigated in the present study. Characteristics of MDA-MB-436 (BRCA1 c.5277 + 1G > A) and HCC1937 (BRCA1 p.Gln1756.Profs*74) were compared to MDA-MB-231 and T47D BRCA1/2 wild-type breast cancer cell lines. ADSCs were cultivated from lipoaspirates of a panel of BRCA1/2- wildtype patients. Interactions of conditioned medium (CM) of these cells with the breast cancer lines were studied using proliferation and migration assays as well as adipokine expression western blot arrays. CM of ADSCs exhibit a dose-dependent stimulation of the proliferation of the breast cancer cell lines. However, of the ADSC preparations tested, only 1 out of 18 samples showed a significant higher stimulation of BRCA1-mutated MDA-MB-436 versus wildtype MDA-MB-231 cells, and all CM revealed lower stimulatory activity for BRCA1-mutated HCC1937 versus wildtype T47D cells. Additionally, migration of breast cancer cells in response to CM of ADSCs proved to be equivalent or slower for BRCA1/2 mutated versus nonmutated cancer cells and, with exception of angiopoietin-like 2, induced expression of adipokines showed no major difference. Effects of media conditioned by normal ADSCs showed largely comparable effects on BRCA1-mutated and wildtype breast cancer cell lines thus advocating lipofilling, preferentially employing allogeneic non-mutated ADSCs.

Cost of Respiratory Syncytial Virus-Associated Acute Lower Respiratory Infection Management in Young Children at the Regional and Global Level: A Systematic Review and Meta-Analysis.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory infection (ALRI) in young children aged <5 years. METHODS: We aimed to identify the global inpatient and outpatient cost of management of RSV-ALRI in young children to assist health policy makers in making decisions related to resource allocation for interventions to reduce severe morbidity and mortality from RSV in this age group. We searched 3 electronic databases including Global Health, Medline, and EMBASE for studies reporting cost data on RSV management in children under 60 months from 2000 to 2017. Unpublished data on the management cost of RSV episodes were collected through collaboration with an international working group (RSV GEN) and claim databases. RESULTS: We identified 41 studies reporting data from year 1987 to 2017, mainly from Europe, North America, and Australia, covering the management of a total of 365 828 RSV disease episodes. The average cost per episode was €3452 (95% confidence interval [CI], 3265-3639) and €299 (95% CI, 295-303) for inpatient and outpatient management without follow-up, and it increased to €8591(95% CI, 8489-8692) and €2191 (95% CI, 2190-2192), respectively, with follow-up to 2 years after the initial event. CONCLUSIONS: Known risk factors (early and late preterm birth, congenital heart disease, chronic lung disease, intensive care unit admission, and ventilator use) were associated with €4160 (95% CI, 3237-5082) increased cost of hospitalization. The global cost of inpatient and outpatient RSV ALRI management in young children in 2017 was estimated to be approximately €4.82 billion (95% CI, 3.47-7.93), 65% of these in developing countries and 55% of global costs accounted for by hospitalization. We have demonstrated that RSV imposed a substantial economic burden on health systems, governments, and the society.

Effects of salinomycin and niclosamide on small cell lung cancer and small cell lung cancer circulating tumor cell lines.

Tumor dissemination and recurrence is attributed to highly resistant cancer stem cells (CSCs) which may constitute a fraction of circulating tumor cells (CTCs). Small cell lung cancer (SCLC) constitutes a suitable model to investigate the relation of CTCs and CSCs due to rapid tumor spread and a high number of CTCs. Expansion of five SCLC CTC lines (BHGc7, 10, 16, 26 and UHGc5) in vitro at our institution allowed for the analysis of CSC markers and cytotoxicity of the CSC-selective drugs salinomycin and niclosamide against CTC single cell suspensions or CTC spheroids/ tumorospheres (TOS). Salinomycin exerted dose-dependent cytotoxicity against the SCLC lines but, with exception of BHGc7 TOS, there was no markedly enhanced activity against TOS. Similarly, niclosamide exhibits high activity against BHGc7 TOS and UHGc5 TOS but not against the other CTC spheroids. High expression of the CSC marker CD133 was restricted to three SCLC tumor lines and the BHGc10 CTC line. All SCLC CTCs are CD24-positive but lack expression of CD44 and ABCG2 in contrast to the SCLC tumor lines which show a phenotype more similar to that of CSCs. The stem cell marker SOX2 was found in all CTC lines and SCLC GLC14/16, whereas elevated expression of Oct-3/4 and Nanog was restricted to BHGc26 and UHGc5. In conclusion, the SCLC CTCs established from patients with relapsed disease lack a typical CSC phenotype in respect to chemosensitivity to CSC-selective drugs, surface markers, expression of pluripotent stem cell and transcription factors.

Can we distinguish respiratory viral infections based on clinical features? A prospective pediatric cohort compared to systematic literature review.

Studies have shown that the predictive value of "clinical diagnoses" of influenza and other respiratory viral infections is low, especially in children. In routine care, pediatricians often resort to clinical diagnoses, even in the absence of robust evidence-based criteria. We used a dual approach to identify clinical characteristics that may help to differentiate infections with common pathogens including influenza, respiratory syncytial virus, adenovirus, metapneumovirus, rhinovirus, bocavirus-1, coronaviruses, or parainfluenza virus: (a) systematic review and meta-analysis of 47 clinical studies published in Medline (June 1996 to March 2017, PROSPERO registration number: CRD42017059557) comprising 49 858 individuals and (b) data-driven analysis of an inception cohort of 6073 children with ILI (aged 0-18 years, 56% male, December 2009 to March 2015) examined at the point of care in addition to blinded PCR testing. We determined pooled odds ratios for the literature analysis and compared these to odds ratios based on the clinical cohort dataset. This combined analysis suggested significant associations between influenza and fever or headache, as well as between respiratory syncytial virus infection and cough, dyspnea, and wheezing. Similarly, literature and cohort data agreed on significant associations between HMPV infection and cough, as well as adenovirus infection and fever. Importantly, none of the abovementioned features were unique to any particular pathogen but were also observed in association with other respiratory viruses. In summary, our "real-world" dataset confirmed published literature trends, but no individual feature allows any particular type of viral infection to be ruled in or ruled out. For the time being, laboratory confirmation remains essential. More research is needed to develop scientifically validated decision models to inform best practice guidelines and targeted diagnostic algorithms.

Anticancer Activity of Fascaplysin against Lung Cancer Cell and Small Cell Lung Cancer Circulating Tumor Cell Lines.

Lung cancer is a leading cause of tumor-associated mortality. Fascaplysin, a bis-indole of a marine sponge, exhibit broad anticancer activity as specific CDK4 inhibitor among several other mechanisms, and is investigated as a drug to overcome chemoresistance after the failure of targeted agents or immunotherapy. The cytotoxic activity of fascaplysin was studied using lung cancer cell lines, primary Non-Small Cell Lung Cancer (NSCLC) and Small Cell Lung Cancer (SCLC) cells, as well as SCLC circulating tumor cell lines (CTCs). This compound exhibited high activity against SCLC cell lines (mean IC50 0.89 µM), as well as SCLC CTCs as single cells and in the form of tumorospheres (mean IC50 0.57 µM). NSCLC lines showed a mean IC50 of 1.15 µM for fascaplysin. Analysis of signal transduction mediators point to an ATM-triggered signaling cascade provoked by drug-induced DNA damage. Fascaplysin reveals at least an additive cytotoxic effect with cisplatin, which is the mainstay of lung cancer chemotherapy. In conclusion, fascaplysin shows high activity against lung cancer cell lines and spheroids of SCLC CTCs which are linked to the dismal prognosis of this tumor type. Derivatives of fascaplysin may constitute valuable new agents for the treatment of lung cancer.

Impact of Outpatient Neuraminidase Inhibitor Treatment in Patients Infected With Influenza A(H1N1)pdm09 at High Risk of Hospitalization: An Individual Participant Data Metaanalysis.

BACKGROUND: While evidence exists to support the effectiveness of neuraminidase inhibitors (NAIs) in reducing mortality when given to hospitalized patients with A(H1N1)pdm09 virus infection, the impact of outpatient treatment on hospitalization has not been clearly established. We investigated the impact of outpatient NAI treatment on subsequent hospitalization in patients with A(H1N1)pdm09 virus infection. METHODS: We assembled general community and outpatient data from 9 clinical centers in different countries collected between January 2009 and December 2010. We standardized data from each study center to create a pooled dataset and then used mixed-effects logistic regression modeling to determine the effect of NAI treatment on hospitalization. We adjusted for NAI treatment propensity and preadmission antibiotic use, including "study center" as a random intercept to account for differences in baseline hospitalization rate between centers. RESULTS: We included 3376 patients with influenza A(H1N1)pdm09, of whom 3085 (91.4%) had laboratory-confirmed infection. Eight hundred seventy-three patients (25.8%) received outpatient or community-based NAI treatment, 928 of 2395 (38.8%) with available data had dyspnea or respiratory distress, and hospitalizations occurred in 1705 (50.5%). After adjustment for preadmission antibiotics and NAI treatment propensity, preadmission NAI treatment was associated with decreased odds of hospital admission compared to no NAI treatment (adjusted odds ratio, 0.24; 95% confidence interval, 0.20-0.30). CONCLUSIONS: In a population with confirmed or suspected A(H1N1)pdm09 and at high risk of hospitalization, outpatient or community-based NAI treatment significantly reduced the likelihood of requiring hospital admission. These data suggest that community patients with severe influenza should receive NAI treatment.

Mesenchymal-Epithelial Transition and Circulating Tumor Cells in Small Cell Lung Cancer.

Cancer patients die of metastatic disease but knowledge regarding individual steps of this complex process of intravasation, spread and extravasation leading to secondary lesions is incomplete. Subpopulations of tumor cells are supposed to undergo an epithelial-mesenchymal transition (EMT), to enter the bloodstream and eventually establish metastases in a reverse process termed mesenchymal-epithelial transition (MET). Small cell lung cancer (SCLC) represents a unique model to study metastatic spread due to early dissemination and relapse, as well as availability of a panel of circulating cancer cell (CTC) lines recently. Additionally, chemosensitive SCLC tumor cells switch to a completely resistant phenotype during cancer recurrence. In advanced disease, SCLC patients display extremely high blood counts of CTCs in contrast to other tumors, like breast, prostate and colon cancer. Local inflammatory conditions at the primary tumor site and recruitment of macrophages seem to increase the shedding of tumor cells into the circulation in processes which may proceed independently of EMT. Since millions of cells are released by tumors into the circulation per day, analysis of a limited number of CTCs at specific time points are difficult to be related to the development of metastatic lesions which may occur approximately one year later. We have obtained a panel of SCLC CTC cell line from patients with relapsing disease, which share characteristic markers of this malignancy and a primarily epithelial phenotype with unique formation of large tumorospheres, containing quiescent and hypoxic cells. Although smoking and inflammation promote EMT, partial expression of vimentin indicates a transitional state with partial EMT in these cell lines at most. The CTC lines exhibit high expression of EpCAM , absent phosphorylation of ß-catenin and background levels of Snail. Provided that these tumor cells had ever undergone EMT, here in advanced disease MET seem to have occurred already in the peripheral circulation. Alternative explanations for the expression of mesenchymal markers of the CTC lines are the heterogeneity of SCLC cells, cooperative migration or altered gene expression in response to the inflammatory tumor microenvironment allowing for tumor spread without EMT/MET.

A prospective observational study of oseltamivir safety and tolerability in infants and young children ≤24 months.

PURPOSE: Infants and young children are at elevated risk of influenza-associated complications, but information on the safety of antiviral therapies is limited in this age group. METHODS: In this prospective open-label observational safety study, children aged ≤24 months with a clinical diagnosis of influenza in routine practice received either no antiviral treatment ('unexposed' group) or oseltamivir treatment or prophylaxis ('exposed' group), according to the physician's judgment. Patients were followed up for 30 days after the baseline visit. RESULTS: Adverse events (AEs) were analysed in 1065 patients; they were reported in 390/711 (54.9%) in the unexposed group, 167/340 (49.1%) patients in the exposed group, and 6/14 prophylaxis patients. Cough and rhinitis were the most common events, reported more often in unexposed children (22.9 and 20.3% respectively) than in exposed children (13.2 and 10.0%; p < 0.001); pyrexia, diarrhoea and vomiting were less common, occurring at similar rates in exposed and unexposed patients. Nasal congestion (3.5%), bronchitis (5.6%) and upper respiratory tract infection (1.5%) were reported more frequently in exposed patients than in unexposed patients (0.7, 2.7 and 0.1% respectively; p < 0.05). In the exposed group, 11.2% of patients (n = 38) experienced 41 AEs considered at least possibly related to oseltamivir, none being assessed as serious. Overall, there were 79 serious AEs in 59 patients. Eleven discontinued treatment because of an AE. CONCLUSIONS: Oseltamivir has a good tolerability profile in infants and children aged ≤24 months. These findings contributed to the recent FDA approval of oseltamivir for treating infants aged 2-51 weeks.

Smoking, inflammation and small cell lung cancer: recent developments.

Small cell lung cancer (SCLC) accounts for 15 % of all lung tumors and represents an invasive neuroendocrine malignancy with poor survival rates. This cancer is highly prevalent in smokers and characterized by inactivation of p53 and retinoblastoma. First in vitro expansion of circulating tumor cells (CTCs) of SCLC patients allowed for investigation of the cell biology of tumor dissemination. In the suggested CTC SCLC model, the primary tumor attracts and educates tumor-promoting and immunosuppressive macrophages which in turn arm CTCs to spread and generate distal lesions. Preexisting inflammatory processes associated with chronic obstructive pulmonary disease (COPD) seem to potentiate the subsequent activity of tumor-associated macrophages (TAM). Activation of signal transducer and activator of transcription 3 (STAT3) and expression of chitinase-3-like 1/YKL-40 in SCLC CTCs seems to be associated with drug resistance. In conclusion, inflammation-associated generation of invasive and chemoresistant CTCs most likely explains the characteristic features of SCLC, namely early dissemination and rapid failure of chemotherapy.

Synergism of cyclin-dependent kinase inhibitors with camptothecin derivatives in small cell lung cancer cell lines.

Advanced small cell lung cancer (SCLC) has a dismal prognosis. Modulation of the camptothecin topotecan, approved for second-line therapy, may improve response. Our recent finding of synergistic enhancement of the cytotoxic activity of camptothecin (CPT) by cyclin-dependent kinase 4 inhibitors is extended here to a panel of camptothecin analogs comprising 10-hydroxy-CPT (HOCPT), topotecan (TPT; 9-[(dimethylamino)-methyl]-10-hydroxy-CPT), 9-amino-CPT (9AC), 9-nitrocamptothecin (rubitecan), SN38 (7-ethyl-10-hydroxycamptothecin) and 10-hydroxy-9-nitrocamptothecin (CPT109) in combination with PD0332991, CDK4I, roscovitine and olomoucine. SCLC cell lines employed are chemoresistant NCI-H417 and DMS153 and the chemosensitive SCLC26A line established at our institution. The CPT analogs exhibiting highest cytotoxicity towards the three SCLC lines tested were SN38 and 9AC, followed by rubitecan, HOCPT, TPT and CPT109. NCI-H417 and DMS153 revealed an approximately 25-fold and 7-fold higher resistance compared to the chemosensitive SCLC26A cell line. Whereas the CDK4/6 inhibitor PD0332991 proved less effective to chemosensitize SCLC cells to CPT analogs, the CDK inhibitors CDK4I, roscovitine and olomoucine gave comparable chemosensitization effects in combination with 9AC, SN38, rubitecan and to a lesser extent with TPT and CPT109, not directly related with topoisomerase mRNA expression. In conclusion, small chemical modifications of the parent CPT structure result in differing cytotoxicities and chemomodulatory effects in combination with CDKIs of the resulting analogs.

A short update on cancer chemoresistance.

Chemotherapeutic interventions in cancer patients are limited by the appearance of chemoresistance. For instance, advanced lung and ovarian cancer patients relapse invariably after few cycles of platinum-based chemotherapy. Disseminated tumors are characterized by genetic instability/heterogeneity, thus containing or generating a repertoire of resistant subpopulations. At the cellular level, altered drug uptake, efflux, and metabolization, as well as modifications of drug targets, increased repair, and decreased cell death complement the limited perfusion and adverse hypoxic/acidic extracellular conditions at the tumor level in retaining cancer cell viability. Similarly, targeted therapy is rendered ineffective by mutations of the specific target protein within a few months or years of administration. Assessment of the expression profiles of resistant tumor cells revealed extensive changes in numerous pathways affecting hundreds of genes. Therefore, reversal of drug resistance will require individual profiles of drug resistance mediators and the combination of several specific drugs, targeting critical components to provide new therapeutic options.

Bromodomain Protein-directed Agents and MYC in Small Cell Lung Cancer.

Small cell lung cancer (SCLC) has a dismal prognosis. In addition to the inactivation of the tumor suppressors TP53 and RB1, tumor-promoting MYC and paralogs are frequently overexpressed in this neuroendocrine carcinoma. SCLC exhibits high resistance to second-line chemotherapy and all attempts of novel drugs and targeted therapy have failed so far to achieve superior survival. MYC and paralogs have key roles in the oncogenic process, orchestrating proliferation, apoptosis, differentiation, and metabolism. In SCLC, MYC-L and MYC regulate the neuroendocrine dedifferentiation of SCLC cells from Type A (ASCL1 expression) to the other SCLC subtypes. Targeting MYC to suppress tumor growth is difficult due to the lack of suitable binding pockets and the most advanced miniprotein inhibitor Omomyc exhibits limited efficacy. MYC may be targeted indirectly via the bromodomain (BET) protein BRD4, which activates MYC transcription, by specific BET inhibitors that reduce the expression of this oncogenic driver. Here, novel BET-directed Proteolysis Targeting Chimeras (PROTACs) are discussed that show high antiproliferative activity in SCLC. Particularly, ARV-825, targeting specifically BRD4, exhibits superior cytotoxic effects on SCLC cell lines and may become a valuable adjunct to SCLC combination chemotherapy.

Targeting KRAS in pancreatic cancer.

Pancreatic cancer has a dismal prognosis due to late detection and lack of efficient therapies. The Kirsten rat sarcoma virus (KRAS) oncogene is mutated in up to 90% of all pancreatic ductal adenocarcinomas (PDACs) and constitutes an attractive target for therapy. However, the most common KRAS mutations in PDAC are G12D (44%), G12V (34%) and G12R (20%) that are not amenable to treatment by KRAS G12C-directed cysteine-reactive KRAS inhibitors such as Sotorasib and Adagrasib that exhibit clinical efficacy in lung cancer. KRAS G12C mutant pancreatic cancer has been treated with Sotorasib but this mutation is detected only in 2%-3% of PDAC. Recently, the KRAS G12D-directed MRTX1133 inhibitor has entered clinical trials and more of such inhibitors are in development. The other KRAS mutations may be targeted indirectly via inhibition of the cognate guanosine exchange factor (GEF) Son of Sevenless 1 that drives KRAS. These agents seem to provide the means to target the most frequent KRAS mutations in PDAC and to improve patient outcomes.

Expression of cytokines in pleural effusions and corresponding cell lines of small cell lung cancer.

Background: Small cell lung cancer (SCLC) is a neuroendocrine aggressive tumor with a dismal prognosis due to the lack of curative therapeutic modalities. Approximately 11% of these patients show a malignant pleural effusion (MPE) that increase in frequency with progression of the disease. In MPE, fluid accumulates due to leaky vessels and mesothelial surfaces as well as impaired removal of fluid due to impaired drainage. Methods: For this investigation, three SCLC MPE samples and supernatants of the corresponding isolated cell lines were analyzed for the content of 105 cytokines, chemokines, and growth factors. Overexpressed pathways including these cytokines were identified using Reactome analysis tools. Results: A large range of cytokines, including vascular endothelial growth factor A (VEGFA), were found to be expressed in the MPEs and conditioned media of the corresponding cell line. These mediators are involved in pathways such as interleukin (IL) signaling, growth factor stimulation, modulation of cell adhesion molecules and proliferative cell signaling. Cytokine expression by the corresponding SCLC cell lines revealed the specific contributions of the tumor cells and included high expression of VEGFA, tumor-promoting factors and mediators exerting immunosuppressive and protumor effects. MPEs used here showed marked stimulation of the proliferation of four permanent SCLC cell lines. Conclusions: MPEs comprise a large number of cytokines with mixed activities on tumor cells and the invading SCLC cells release a number of protumor mediators and induce an immunosuppressive pleural environment.

BRD4-targeting PROTACs Synergize With Chemotherapeutics Against Osteosarcoma Cell Lines.

BACKGROUND/AIM: Osteosarcoma at an advanced stage has a poor outcome, and novel targeted therapies are needed, especially for metastatic disease. Bromodomain inhibitors (BETi) are epigenetic modulators that broadly impair the expression of oncogenic proteins and exert antitumor effects. BETi can be combined with chemotherapeutics to increase therapeutic responses with superior effects in the form of proteolysis targeting chimeras (PROTACs) that degrade proteins of interest (POI) in multiple cycles. This work aimed to investigate the efficacy of BETi, such as JQ1, dBET57, and MZ1 PROTACs in combination with cytotoxic drugs against osteosarcoma cell lines. MATERIALS AND METHODS: Chemosensitivity of the osteosarcoma cell lines HOS, Saos-2, MG-63, and G292 were tested with BET-directed agents alone or in combination with cytotoxic drugs comprising cisplatin, doxorubicin, topotecan, and gemcitabine using cell viability assays. RESULTS: The BET degraders exhibited highest toxicity to HOS cells and showed synergistic activity in combination with the chemotherapeutics, except for the degrader - topotecan/gemcitabine combinations. Highest synergy between BET agents and chemotherapeutics were found for the more chemoresistant Saos-2 cells and potentiation of toxicity in MG-63 cells for the BET agents - doxorubicin combinations and the MZ1-topotecan pair. HOS and Saos-2 cell lines had reduced protein expression of AXL, BCL-X, e-cadherin, CAIX, EpCAM, ErbB2, and vimentin in response to JQ1, MZ1, and BET57. CONCLUSION: The study suggests that the application of novel BET PROTACs in combination with chemotherapeutics could represent a new therapeutic option to improve the therapy of osteosarcomas. First orally available PROTACs have reached clinical trials.

Disease Burden and Inpatient Management of Children with Acute Respiratory Viral Infections during the Pre-COVID Era in Germany: A Cost-of-Illness Study.

Respiratory viral infections (RVIs) are common reasons for healthcare consultations. The inpatient management of RVIs consumes significant resources. From 2009 to 2014, we assessed the costs of RVI management in 4776 hospitalized children aged 0-18 years participating in a quality improvement program, where all ILI patients underwent virologic testing at the National Reference Centre followed by detailed recording of their clinical course. The direct (medical or non-medical) and indirect costs of inpatient management outside the ICU ('non-ICU') versus management requiring ICU care ('ICU') added up to EUR 2767.14 (non-ICU) vs. EUR 29,941.71 (ICU) for influenza, EUR 2713.14 (non-ICU) vs. EUR 16,951.06 (ICU) for RSV infections, and EUR 2767.33 (non-ICU) vs. EUR 14,394.02 (ICU) for human rhinovirus (hRV) infections, respectively. Non-ICU inpatient costs were similar for all eight RVIs studied: influenza, RSV, hRV, adenovirus (hAdV), metapneumovirus (hMPV), parainfluenza virus (hPIV), bocavirus (hBoV), and seasonal coronavirus (hCoV) infections. ICU costs for influenza, however, exceeded all other RVIs. At the time of the study, influenza was the only RVI with antiviral treatment options available for children, but only 9.8% of influenza patients (non-ICU) and 1.5% of ICU patients with influenza received antivirals; only 2.9% were vaccinated. Future studies should investigate the economic impact of treatment and prevention of influenza, COVID-19, and RSV post vaccine introduction.