Purpose: Acquired chemoresistance is a frequent event in small cell lung cancer (SCLC), one of the deadliest human malignancies. Histone deacetylase inhibitors (HDACi) have been shown to synergize with different chemotherapeutic agents including cisplatin. Accordingly, we aimed to investigate the dual targeting of HDAC inhibition and chemotherapy in SCLC. Experimental Design: The efficacy of HDACi and chemotherapy in SCLC was investigated both in vitro and in vivo. Synergistic drug interactions were calculated based on the HSA model (Combenefit software). Results from the proteomic analysis were confirmed via ICP-MS, cell-cycle analysis, and comet assays. Results: Single entinostat- or chemotherapy significantly reduced cell viability in human neuroendocrine SCLC cells. The combination of entinostat with either cisplatin, carboplatin, irinotecan, epirubicin, or etoposide led to strong synergy in a subset of resistant SCLC cells. Combination treatment with entinostat and cisplatin significantly decreased tumor growth in vivo. Proteomic analysis comparing the groups of SCLC cell lines with synergistic and additive response patterns indicated alterations in cell-cycle regulation and DNA damage repair. Cell-cycle analysis revealed that cells exhibiting synergistic drug responses displayed a shift from G1 to S-phase compared with cells showing additive features upon dual treatment. Comet assays demonstrated more DNA damage and decreased base excision repair in SCLC cells more responsive to combination therapy. Conclusions: In this study, we decipher the molecular processes behind synergistic interactions between chemotherapy and HDAC inhibition. Moreover, we report novel mechanisms to overcome drug resistance in SCLC, which may be relevant to increasing therapeutic success.

Background: Although the number of lung transplantations (LTx) performed worldwide for coronavirus disease 2019 (COVID-19)-induced acute respiratory distress syndrome (ARDS) is still low, there is general agreement that this treatment can save a subgroup of the most severely ill patients with irreversible lung damage. However, the true proportion of patients eligible for LTx, the overall outcome and the impact of LTx on the pandemic are unknown. Methods: A retrospective analysis was performed using a nationwide registry of hospitalised patients with confirmed severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection admitted between 1 January 2020 and 30 May 2021 in Austria. Patients referred to one of the two Austrian LTx centres were analysed, and grouped into patients accepted and rejected for LTx. Detailed outcome analysis was performed for all patients who received a LTx for post-COVID-19 ARDS and compared with patients who underwent LTx for other indications. Results: Between 1 January 2020 and 30 May 2021, 39 485 patients were hospitalised for COVID-19 in Austria. 2323 required mechanical ventilation and 183 received extracorporeal membrane oxygenation (ECMO) support. 106 patients with severe COVID-19 ARDS were referred for LTx. Of these, 19 (18%) underwent LTx. 30-day mortality after LTx was 0% for COVID-19 ARDS transplant recipients. At a median follow-up of 134 (47–450) days, 14 out of 19 patients were alive. Conclusions: Early referral of ECMO patients to a LTx centre is pivotal in order to select patients eligible for LTx. Transplantation offers excellent midterm outcomes and should be incorporated in the treatment algorithm of post-COVID-19 ARDS.

Lung transplantation (LTx) can be considered for selected patients suffering from COVID-19 acute respiratory distress syndrome (ARDS). Secondary sclerosing cholangitis in critically ill (SSC-CIP) patients has been described as a late complication in COVID-19 ARDS survivors, however, rates of SSC-CIP after LTx and factors predicting this detrimental sequela are unknown. This retrospective analysis included all LTx performed for post-COVID ARDS at 8 European LTx centers between May 2020 and January 2022. Clinical risk factors for SSC-CIP were analyzed over time. Prediction of SSC-CIP was assessed by ROC-analysis. A total of 40 patients were included in the analysis. Fifteen patients (37.5%) developed SSC-CIP. GGT at the time of listing was significantly higher in patients who developed SSC-CIP (median 661 (IQR 324-871) vs 186 (109-346); p = 0.001). Moreover, higher peak values for GGT (585 vs 128.4; p < 0.001) and ALP (325 vs 160.2; p = 0.015) were found in the ‘SSC’ group during the waiting period. Both, GGT at the time of listing and peak GGT during the waiting time, could predict SSC-CIP with an AUC of 0.797 (95% CI: 0.647-0.947) and 0.851 (95% CI: 0.707-0.995). Survival of ‘SSC’ patients was severely impaired compared to ‘no SSC’ patients (1-year: 46.7% vs 90.2%, log-rank p = 0.004). SSC-CIP is a severe late complication after LTx for COVID-19 ARDS leading to significant morbidity and mortality. GGT appears to be a sensitive parameter able to predict SSC-CIP even at the time of listing.

Background: Pulmonary metastasectomy (PM) is a standard procedure in the treatment of stage IV colorectal cancer (CRC). In most centers the indication for PM is solely based on clinical factors without taking the tumor biology into account. This results in diverse outcomes ranging from long-term remission to early recurrence. Inflammation is considered a hallmark of cancer development and progression. On the other hand the accessibility of CRC cells to the immune system reflects the grade of tumor aggressiveness. We sought to investigate the impact of cyclooxygenase-2 (COX-2) and prostaglandin-E2 (PGE2) expression in pulmonary metastases on different outcome parameters following PM. Methods: From 04/2009 to 11/2013 53 patients with complete PM for CRC were included in this single-center study. Tissue samples of resected pulmonary metastases and available corresponding primaries were collected and assessed by immunohistochemistry for COX-2 and PGE2 expression of the tumor tissue and the peritumoral stroma. Results were correlated with clinical outcome parameters. Results: COX-2 and PGE2 were detected in nearly every pulmonary CRC metastasis. Staining intensities of pulmonary metastases correlated only weakly with intensities found in primary tumors. When dividing metastases in high expressing and low expressing tumors, a trend towards longer recurrence free survival and improved survival was found in tumors with strong COX-2 and PGE2 staining. Conclusions: In conclusion, this pilot study shows that COX-2 and PGE2 are uniformly overexpressed in pulmonary metastases from CRC. High expression of COX-2 and PGE2 seems to reflect a beneficial tumor biology with late tumor recurrence and prolonged overall survival after PM.

(1) Background: Mitral regurgitation (MR) is associated with increased mortality and frequent hospital admissions. Although mitral valve intervention offers improved clinical outcomes for MR, it is not feasible in many cases. Moreover, conservative therapeutic opportunities remain limited. The aim of this study was to evaluate the impact of ACE inhibitors and angiotensin receptor blockers (ACE-I/ARB) on elderly patients with moderate-to-severe MR and mildly reduced to preserved ejection fraction. (2) Methods: In total, 176 patients were included in our hypothesis-generating, single-center observational study. Hospitalization for heart failure and all-cause death have been defined as the combined 1-year primary endpoint. (3) Results: Patients treated with ACE-I/ARB showed a lower risk for the combined endpoint of death and heart failure-related readmission (HR 0.52 95%CI 0.27–0.99; p = 0.046), even after adjustment for EUROScoreII and frailty (HR 0.52 95%CI 0.27–0.99; p = 0.049) (4) Conclusions: The use of an ACE-I/ARB in patients with moderate-to-severe MR and preserved to mildly reduced left-ventricular ejection fraction (LVEF) significantly associates with improved clinical outcome and might be indicated as a valuable therapeutic option in conservatively treated patients.

Small cell lung cancer (SCLC) is an aggressive thoracic disease characterized by rapid proliferation and early metastatic spread. The survival outcomes for patients with SCLC remain notoriously poor, underlining that only modest improvements have been achieved in clinical settings to date. However, insights gained from human tumors and preclinical models in recent years have shed light on the heterogeneous molecular profile of SCLC. Numerous research groups have, therefore, begun to stratify SCLC into subgroups based on differential transcription factor expression, the tumor immune microenvironment, and other criteria. As SCLC subtypes show major differences in their molecular landscape and biological behavior, they may offer unique therapeutic vulnerabilities and serve as a framework for future personalized clinical trials. Here, we summarize impactful classification attempts from the past 10 years, highlighting discrepancies and connections between the nomenclature of each study, and expound upon relevant factors of SCLC biology influencing subtype composition and plasticity. This review delves into the implications of subgrouping for understanding and treating SCLC, as well as potential future directions for SCLC research.