Small cell lung cancers (SCLCs) and extrapulmonary small cell cancers (SCCs) are very aggressive tumors arising de novo as primary small cell cancer with characteristic genetic lesions in RB1 and ...TP53. Based on murine models, neuroendocrine stem cells of the terminal bronchioli have been postulated as the cellular origin of primary SCLC. However, both in lung and many other organs, combined small cell/non‐small cell tumors and secondary transitions from non‐small cell carcinomas upon cancer therapy to neuroendocrine and small cell tumors occur. We define features of “small cell‐ness” based on neuroendocrine markers, characteristic RB1 and TP53 mutations and small cell morphology. Furthermore, here we identify a pathway driving the pathogenesis of secondary SCLC involving inactivating NOTCH mutations, activation of the NOTCH target ASCL1 and canonical WNT‐signaling in the context of mutual bi‐allelic RB1 and TP53 lesions. Additionaly, we explored ASCL1 dependent RB inactivation by phosphorylation, which is reversible by CDK5 inhibition. We experimentally verify the NOTCH‐ASCL1‐RB‐p53 signaling axis in vitro and validate its activation by genetic alterations in vivo. We analyzed clinical tumor samples including SCLC, SCC and pulmonary large cell neuroendocrine carcinomas and adenocarcinomas using amplicon‐based Next Generation Sequencing, immunohistochemistry and fluorescence in situ hybridization. In conclusion, we identified a novel pathway underlying rare secondary SCLC which may drive small cell carcinomas in organs other than lung, as well.
What's new?
Using next generation sequencing and establishing features of ‘small cell‐ness’, we identified a NOTCH‐ASCL1‐RB1‐TP53 signaling axis driving small cell cancers. In contrast to the previously described bi‐allelic RB1/TP53 loss in neuroendocrine stem cells as origin of primary small cell neuroendocrine cancers, the NOTCH‐ASCL1 mediated signaling defines an alternative pathway driving secondary small cell neuroendocrine cancers arising from non‐small cell cancers. Moreover, we show a preclinical rational for therapeutically testing WNT‐inhibitors in small cell cancers.
Outcome of immune checkpoint inhibition in cancer can be predicted by measuring PDL1 expression of tumor cells. Search for additional biomarkers led to tumor mutational burden (TMB) as surrogate ...marker for neoantigens presented. While TMB was previously determined via whole exome sequencing (WES), there have been approaches with comprehensive gene panels as well. We sequenced samples derived from formalin-fixed tumors, a POLE mutated cell line and standard DNA by WES and five different panels. If available, normal tissue was also exome sequenced. Sequencing data was analyzed by commercial software solutions and an in-house pipeline. A robust Pearson correlation (R = 0.9801 ± 0.0167; mean ± sd; N = 7) was determined for the different panels in a tumor paired normal setting for WES. Expanded analysis on tumor only exome sequenced samples yielded similar correlation (R = 0.9439 ± 0.0632; mean ± sd; N = 14). Remaining germline variants increased TMB in WES by 5.761 ± 1.953 (mean ± sd.; N = 7) variants per megabase (v/mb) for samples including synonymous variants and 3.883 ± 1.38 v/mb for samples without synonymous variants compared to tumor-normal paired calling results. Due to limited sample numbers in this study, additional replication is suggested for a clinical setting. Remaining germline variants in a tumor-only setting and artifacts caused by different library chemistries construction might affect the results.
Microsatellite instability (MSI), a common alteration in endometrial cancers (EC) is known as a biomarker for immune checkpoint therapy response alongside screening for Lynch Syndrome (LS). However, ...former studies described challenging MSI profiles in EC hindering analysis by using MSI testing methods intensively validated for colorectal cancer (CRC) only. In order to reduce false negatives, this study examined four different PCR-based approaches for MSI testing using 25 EC samples already tested for mismatch repair deficiency (dMMR). In a follow up validation set of 75 EC samples previously tested both for MMR and MSI, the efficiency of a seven-marker system corresponding to the Idylla system was further analyzed. Both Bethesda and Promega marker panels require trained operators to overcome interpretation complexities caused by either hardly visible additional peaks of one and two nucleotides, or small shifts in microsatellite repeat length. Using parallel sequencing adjustment of bioinformatics is needed. Applying the Idylla MSI assay, an evaluation of input material is more crucial for reliable results and is indispensable. Following MMR deficiency testing as a first-line screening procedure, additional testing with a PCR-based method is necessary if inconclusive staining of immunohistochemistry (IHC) must be clarified.
Purpose The efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in non-small cell lung cancer (NSCLC) has been linked to activating mutations in the EGFR gene. So far these ...mutations have been extensively characterized in established cell lines. The aim of this study was to determine the effects of EGFR mutations on downstream signaling in human tumor specimens. Methods We have looked for mutations of the EGFR gene in specimens of 67 patients with NSCLC and correlated these with EGFR phosphorylation and the activity of its three main downstream signaling cascades Akt, MAPK and Stat3 by immunohistochemistry. Results We show that the phosphorylation of tyrosine residues 922 and 1173, but not 1068, are primarily affected by the activating EGFR mutations. Akt activity was significantly higher in patients with EGFR mutations but we found no difference in Stat3 or MAPK phosphorylation. Our results suggest that EGFR mutations not only increase receptor activity, but also alter responses of downstream signaling cascades in human NSCLCs and that these finding differ from results obtained in cell lines.
To derive and externally validate a copeptin-based parsimonious score to predict unfavorable outcome 3 months after an acute ischemic stroke (AIS).
The derivation cohort consisted of patients with ...AIS enrolled prospectively at the University Hospital Basel, Switzerland. The validation cohort was prospectively enrolled after the derivation cohort at the University Hospital of Bern and University Hospital Basel, Switzerland, as well as Frankfurt a.M., Germany. The score components were copeptin levels, age, NIH Stroke Scale, and recanalization therapy (CoRisk score). Copeptin levels were measured in plasma drawn within 24 hours of AIS and before any recanalization therapy. The primary outcome of disability and death at 3 months was defined as modified Rankin Scale score of 3 to 6.
Overall, 1,102 patients were included in the analysis; the derivation cohort contributed 319 patients, and the validation cohort contributed 783. An unfavorable outcome was observed among 436 patients (40%). For the 3-month prediction of disability and death, the CoRisk score was well calibrated in the validation cohort, for which the area under the receiver operating characteristic curve was 0.819 (95% confidence interval CI 0.787-0.849). The calibrated CoRisk score correctly classified 75% of patients (95% CI 72-78). The net reclassification index between the calibrated CoRisk scores with and without copeptin was 46% (95% CI 32-60).
The biomarker-based CoRisk score for the prediction of disability and death was externally validated, was well calibrated, and performed better than the same score without copeptin.
NCT00390962 (derivation cohort) and NCT00878813 (validation cohort).
Whether high-dose cytarabine-based salvage chemotherapy, administered to induce complete remission in patients with poor responsive or relapsed acute myeloid leukaemia scheduled for allogeneic ...haematopoietic stem-cell transplantation (HSCT) after intensive conditioning confers a survival advantage, is unclear.
To test salvage chemotherapy before allogeneic HSCT, patients aged between 18 and 75 years with non-favourable-risk acute myeloid leukaemia not in complete remission after first induction or untreated first relapse were randomly assigned 1:1 to remission induction with high-dose cytarabine (3 g/m2 intravenously, 1 g/m2 intravenously for patients >60 years or with a substantial comorbidity) twice daily on days 1–3 plus mitoxantrone (10 mg/m2 intravenously) on days 3–5 or immediate allogeneic HSCT for the disease control group. Block randomisation with variable block lengths was used and patients were stratified by age, acute myeloid leukaemia risk, and disease status. The study was open label. The primary endpoint was treatment success, defined as complete remission on day 56 after allogeneic HSCT, with the aim to show non-inferiority for disease control compared with remission induction with a non-inferiority-margin of 5% and one-sided type 1 error of 2·5%. The primary endpoint was analysed in both the intention-to-treat (ITT) population and in the per-protocol population. The trial is completed and was registered at ClinicalTrials.gov, NCT02461537.
281 patients were enrolled between Sept 17, 2015, and Jan 12, 2022. Of 140 patients randomly assigned to disease control, 135 (96%) proceeded to allogeneic HSCT, 97 (69%) after watchful waiting only. Of 141 patients randomly assigned to remission induction, 134 (95%) received salvage chemotherapy and 128 (91%) patients subsequently proceeded to allogeneic HSCT. In the ITT population, treatment success was observed in 116 (83%) of 140 patients in the disease control group versus 112 (79%) of 141 patients with remission induction (test for non-inferiority, p=0·036). Among per-protocol treated patients, treatment success was observed in 116 (84%) of 138 patients with disease control versus 109 (81%) of 134 patients in the remission induction group (test for non-inferiority, p=0·047). The difference in treatment success between disease control and remission induction was estimated as 3·4% (95% CI –5·8 to 12·6) for the ITT population and 2·7% (–6·3 to 11·8) for the per-protocol population. Fewer patients with disease control compared with remission induction had non-haematological adverse events grade 3 or worse (30 21% of 140 patients vs 86 61% of 141 patients, χ2 test p<0·0001). Between randomisation and the start of conditioning, with disease control two patients died from progressive acute myeloid leukaemia and zero from treatment-related complications, and with remission induction two patients died from progressive acute myeloid leukaemia and two from treatment-related complications. Between randomisation and allogeneic HSCT, patients with disease control spent a median of 27 days less in hospital than those with remission induction, ie, the median time in hospital was 15 days (range 7–64) versus 42 days (27–121, U test p<0·0001), respectively.
Non-inferiority of disease control could not be shown at the 2·5% significance level. The rate of treatment success was also not statistically better for patients with remission induction. Watchful waiting and immediate transplantation could be an alternative for fit patients with poor response or relapsed acute myeloid leukaemia who have a stem cell donor available. More randomised controlled intention-to-transplant trials are needed to define the optimal treatment before transplantation for patients with active acute myeloid leukaemia.
DKMS and the Gert and Susanna Mayer Stiftung Foundation.
The opening of intracellular potassium channels his been suggested as a mechanism regulating hair growth. Enhancing the flu of potassium ions is a mechanism shared by several structurally diverse ...antihypertensive agents including minoxidil sulfate (the active metabolite of minoxidil), pinacidil, P 1075 (a potent pinacidil analog) RP-49 356, diazoxide, cromakalim, and nicorandil. Of these drugs minoxidil, pinacidil, and diazoxide have been reported to elicit hypertrichosis in humans, This potassium channel hypertrichosis was examined by testing these drugs for effects on hair growth o h in vitro and in vivo. For the in vitro studies, mouse vibrissae follicles were cultured for 3 d with drug and the effect on hair growth were measured by metabolic labeling. All drugs, except diazoxide, ecchanged cysteine incorporation o the hair shafts of the cultured vibrissae. Diazoxide was in vivo by measuring hair growth effects in balding strumptail macaque monkeys. The drugs were administered topically to defined sites on balding scalps once per day for 4- 5 months and the amount of hair grown was determined by monthly measurements of shaved hair weight. Three of the drugs produced significant increases in hair weight whereas, the RP – 49, 356 had no effect. These studies provide correlative evidence that the opening of potassium channels is an important regulatory mechanism for hair growth. This provides the impetus for further studies on this potentially important mechanism affecting hair biology.
A high level of diversity has already been observed among the planets of our own Solar System. As such, one expects extrasolar planets to present a wide range of distinctive features, therefore the ...characterisation of Earth- and super Earth-like planets is becoming of key importance in scientific research. The S
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aracerisation) mission proposal of this paper represents one possible approach to realising these objectives. The mission goals of S
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include the detailed characterisation of a wide variety of exoplanets, ranging from terrestrial planets to gas giants. More specifically, S
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will determine atmospheric properties such as cloud coverage, surface pressure and atmospheric composition, and may also be capable of identifying basic surface features. To resolve a planet with a semi major axis of down to 1.4 AU and 30 pc distant S
earch
will have a mirror system consisting of two segments, with elliptical rim, cut out of a parabolic mirror. This will yield an effective diameter of 9 m along one axis. A phase mask coronagraph along with an integral spectrograph will be used to overcome the contrast ratio of star to planet light. Such a mission would provide invaluable data on the diversity present in extrasolar planetary systems and much more could be learned from the similarities and differences compared to our own Solar System. This would allow our theories of planetary formation, atmospheric accretion and evolution to be tested, and our understanding of regions such as the outer limit of the Habitable Zone to be further improved.
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