Structure-Guided Identification of Black Cohosh (Actaea racemosa) Triterpenoids with In Vitro Activity against Multiple Myeloma

Black cohosh is a well-established medicinal plant and preparations of its rootstock are used for the treatment of mild climacteric complaints. The compounds considered responsible for the therapeutic effect are triterpene glycosides, characterized by a cycloartane scaffold and a pentose moiety. Because some of these triterpenoids were found to exhibit relevant cytotoxic effects against human breast cancer cells, we decided to investigate their activity on multiple myeloma cell lines NCI-H929, OPM-2, and U266. In a systematic approach, we initially tested three known cytotoxic compounds of three different triterpenoid types, revealing the cimigenol-type triterpenoid as the most active constituent. In a second round, seven naturally occurring cimigenol derivatives were compared with respect to their sugar moiety and their substitution pattern at position C-25, leading to 25-O-methylcimigenol-3-O-α-L-arabinopyranoside as the most potent candidate. Interestingly, not only the methyl group at position C-25 increased the cytotoxic effect but also the arabinose moiety at position C-3 had an impact on the activity. The variety of cimigenol derivatives, moreover, allowed a detailed discussion of their structure-activity relationships, not only for their effect on multiple myeloma cells but also with regard to previous studies on the cytotoxicity of black cohosh triterpenoids

Lysine Residue at Position 22 of the AID Protein Regulates Its Class Switch Activity

Background: Activation induced deaminase (AID) mediates class switch recombination and somatic hypermutation of immunoglobulin (Ig) genes in germinal centre B cells. In order to regulate its specific activity and as a means to keep offtarget mutations low, several mechanisms have evolved, including binding to specific cofactors, phosphorylation and destabilization of nuclear AID protein. Although ubiquitination at lysine residues of AID is recognized as an essential step in initiating degradation of nuclear AID, any functional relevance of lysine modifications has remained elusive. Methodology/Principal Findings: Here, we report functional implications of lysine modifications of the human AID protein by generating a panel of lysine to arginine mutants of AID and assessment of their catalytic class switch activity. We found that only mutation of Lys22 to Arg resulted in a significant reduction of class switching to IgG1 in transfected primary mouse B cells. This decrease in activity was neither reflected in reduced hypermutation of Ig genes in AID-mutant transfected DT40 B cell lines nor recapitulated in bacterial deamination assays, pointing to involvement of post-translational modification of Lys22 for AID activity in B cells. Conclusions/Significance: Our results imply that lysine modification may represent a novel level of AID regulation and tha

Differential diagnostic challenge of chronic neutrophilic leukemia in a patient with prolonged leukocytosis

Our interesting case deals with the clinical and morphological aspects of a chronic neutrophilic leukemia and the critical evaluation of differential diagnosis of leukemoid reaction in bone marrow biopsies

Pembrolizumab alone or with chemotherapy for recurrent or metastatic head and neck squamous cell carcinoma: Health-related quality-of-life results from KEYNOTE-048

Immunotherapy; Pembrolizumab; Quality of lifeInmunoterapia; Pembrolizumab; Calidad de vidaImmunoteràpia; Pembrolizumab; Qualitat de vidaObjectives To assess health-related quality of life (HRQoL) with first-line pembrolizumab, pembrolizumab-chemotherapy, or cetuximab-chemotherapy in recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) in the phase 3 KEYNOTE-048 trial (NCT02358031). Materials and Methods HRQoL was measured using the European Organisation for Research and Treatment of Cancer 30-question quality-of-life (EORTC QLQ-C30), the EORTC 35-question quality-of-life head and neck cancer–specific module (EORTC QLQ-H&N35), and the EuroQol 5-dimension 3-level instruments (EQ-5D-3L). Secondary endpoints included mean change from baseline in EORTC QLQ-C30 global health status/quality of life (GHS/QoL) at week 15 and time to deterioration (TTD) in EORTC QLQ-C30 GHS/QoL and EORTC QLQ-H&N35 pain and swallowing. Results Of 882 enrolled participants, 844 received ≥ 1 dose of study treatment and completed ≥ 1 HRQoL assessment; adherence was ≥ 79% at week 15 across treatment groups. At week 15, EORTC QLQ-C30 GHS/QoL scores remained stable; no clinically meaningful between-group differences were observed (least squares mean difference, pembrolizumab vs cetuximab-chemotherapy, 0.24; 95% CI, −3.34 to 3.82; pembrolizumab-chemotherapy vs cetuximab-chemotherapy, 0.40; 95% CI, −3.46 to 4.26). Median TTD in EORTC QLQ-C30 GHS/QoL and EORTC QLQ-H&N35 pain and swallowing scores was not reached over 51 weeks across groups, showing stable HRQoL. TTD was similar between groups for EORTC QLQ-C30 GHS/QoL (pembrolizumab vs cetuximab-chemotherapy: HR, 1.38; 95% CI, 0.95–2.00; pembrolizumab-chemotherapy vs cetuximab-chemotherapy: HR, 1.37; 95% CI, 0.94–2.00), as was TTD in EORTC QLQ-H&N35 pain and swallowing scores. Conclusions Pembrolizumab monotherapy and pembrolizumab-chemotherapy extended OS while maintaining HRQoL, further supporting first-line use for R/M HNSCC.Funding for this research was provided by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA

Cytotoxic constituents and a new hydroxycinnamic acid derivative from Leontodon saxatilis (Asteraceae, Cichorieae)

In our ongoing research for the discovery of new constituents with antimyeloma activity, we investigated 15 compounds present in the aerial parts of Leontodon saxatilis for their cytotoxic potential against NCI-H929, U266, and OPM2 cell lines. One of the isolated compounds displayed a new natural product and was identified as 5-feruloyl-2α-hydroxyquinic acid after LC-MS and NMR experiments. Of the remaining compounds, cichoric acid and three flavone glycosides, apigenin 4'-O-β-d-glucoside, luteolin 7-O-β-d-glucoside and luteolin 4'-O-β-d-glucoside, showed moderate cytotoxic activity, whereas the effects of two aglyones apigenin and luteolin were more pronounced. Though the cytotoxic potential of the two aglycones (against other cell lines) was reported in various studies, our work moreover showed that cooccurrence of these two compounds with similar components of lower activity led to comparable results and at the same time minimized the damage of healthy fibroblast cells. Thus, our work could be a starting point for additional studies on the synergistic effect of similar components against myeloma cell lines

Pembrolizumab Alone or With Chemotherapy for Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma in KEYNOTE-048: Subgroup Analysis by Programmed Death Ligand-1 Combined Positive Score

Quimioteràpia; Carcinoma de cèl·lules escamoses de cap i collQuimioterapia; Carcinoma de células escamosas de cabeza y cuelloChemotherapy; Head and neck squamous cell carcinomaPURPOSE The phase III KEYNOTE-048 (ClinicalTrials.gov identifier: NCT02358031) trial of pembrolizumab in recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) included planned efficacy analyses in the total population and in participants with programmed death ligand-1 (PD-L1) combined positive score (CPS) ≥ 1 and CPS ≥ 20. To further characterize the predictive value of PD-L1 expression on outcome, we conducted efficacy analyses in the PD-L1 CPS < 1 and CPS 1-19 subgroups in KEYNOTE-048. METHODS Participants with R/M HNSCC and no prior systemic therapy for R/M disease were randomly assigned 1:1:1 to pembrolizumab, pembrolizumab-chemotherapy, or cetuximab-chemotherapy. Post hoc efficacy analyses of the PD-L1 CPS < 1 and CPS 1-19 subgroups were performed. RESULTS Of 882 participants enrolled, 128 had PD-L1 CPS < 1 and 373 had CPS 1-19. For pembrolizumab versus cetuximab-chemotherapy, the median overall survival was 7.9 versus 11.3 months in the PD-L1 CPS < 1 subgroup (hazard ratio [HR], 1.51 [95% CI, 0.96 to 2.37]) and 10.8 versus 10.1 months in the CPS 1-19 subgroup (HR, 0.86 [95% CI, 0.66 to 1.12]). For pembrolizumab-chemotherapy versus cetuximab-chemotherapy, the median overall survival was 11.3 versus 10.7 months in the PD-L1 CPS < 1 subgroup (HR, 1.21 [95% CI, 0.76 to 1.94]) and 12.7 versus 9.9 months in the CPS 1-19 subgroup (HR, 0.71 [95% CI, 0.54 to 0.94]). CONCLUSION Increased efficacy of pembrolizumab or pembrolizumab-chemotherapy was observed with increasing PD-L1 expression. PD-L1 CPS < 1 subgroup analysis was limited by small participant numbers. Results from the PD-L1 CPS 1-19 subgroup support previous findings of treatment benefit with pembrolizumab monotherapy and pembrolizumab-chemotherapy in patients with PD-L1 CPS ≥ 1 tumors. Although PD-L1 expression is informative, exploration of additional predictive biomarkers is needed for low PD-L1–expressing HNSCC.Funding for this research was provided by Merck Sharp & Dohme Corp, a subsidiary of Merck & Co Inc, Kenilworth, NJ