Explore the vast range of titles available.

Programmed death ligand 1 (PD-L1) expression is an efficient strategy of tumor cells to escape immunological eradiation. However, only little is known about the factors that affect the cellular expression levels. Here we assessed the PD-L1 expression on different breast cancer cell lines under standard in vitro culture conditions and as a function of Epirubicin or Paclitaxel treatment. Moreover, we evaluated the expression in immunodeficient tumor mice as well as in humanized tumor mice (i.e., in the presence of a human immune system). We found highest PD-L1 levels in JIMT-1 and MDA-MB-231 cells. Epirubicin treatment caused a decrease and Paclitaxel treatment an increased PD-L1 expression in MDA-MB-231 cells. In addition, we identified nuclear PD-L1 in MDA-MB-231 cells. All in vivo transplanted breast cancer cell lines downregulated PD-L1 expression compared to their in vitro counterpart. Neither the gene copy number nor the presence of human immune system in humanized tumor mice had an effect on the PD-L1 content. We demonstrate that the degree of PD-L1 expression amongst breast cancer cell lines varies considerably. In addition, cytotoxic treatments and other extrinsic parameters differentially affect the expression. Hence, further investigations including in vivo evaluations are necessary to understand PD-L1 regulation for advanced breast cancer stratification.

Gene expression analysis of rare or heterogeneous cell populations such as disseminated cancer cells (DCCs) requires a sensitive method allowing reliable analysis of single cells. Therefore, we developed and explored the feasibility of a quantitative PCR (qPCR) assay to analyze single-cell cDNA pre-amplified using a previously established whole transcriptome amplification (WTA) protocol. We carefully selected and optimized multiple steps of the protocol, e.g. re-amplification of WTA products, quantification of amplified cDNA yields and final qPCR quantification, to identify the most reliable and accurate workflow for quantitation of gene expression of the ERBB2 gene in DCCs. We found that absolute quantification outperforms relative quantification. We then validated the performance of our method on single cells of established breast cancer cell lines displaying distinct levels of HER2 protein. The different protein levels were faithfully reflected by transcript expression across the tested cell lines thereby proving the accuracy of our approach. Finally, we applied our method to breast cancer DCCs of a patient undergoing anti-HER2-directed therapy. Here, we were able to measure ERBB2 expression levels in all HER2-protein-positive DCCs. In summary, we developed a reliable single-cell qPCR assay applicable to measure distinct levels of ERBB2 in DCCs.

While cell‐free liquid biopsy (cfLB) approaches provide simple and inexpensive disease monitoring, cell‐based liquid biopsy (cLB) may enable additional molecular genetic assessment of systemic disease heterogeneity and preclinical model development. We investigated 71 blood samples of 62 patients with various advanced cancer types and subjected enriched circulating tumor cells (CTCs) to organoid culture conditions. CTC‐derived tumoroid models were characterized by DNA/RNA sequencing and immunohistochemistry, as well as functional drug testing. Results were linked to molecular features of primary tumors, metastases, and CTCs; CTC enumeration was linked to disease progression. Of 52 samples with positive CTC counts (≥1) from eight different cancer types, only CTCs from two salivary gland cancer (SGC) patients formed tumoroid cultures (P = 0.0005). Longitudinal CTC enumeration of one SGC patient closely reflected disease progression during treatment and revealed metastatic relapse earlier than clinical imaging. Multiomics analysis and functional in vitro drug testing identified potential resistance mechanisms and drug vulnerabilities. We conclude that cLB might add a functional dimension (to the genetic approaches) in the personalized management of rare, difficult‐to‐treat cancers such as SGC. We quantified and cultured circulating tumor cells (CTCs) of 62 patients with various cancer types and generated CTC‐derived tumoroid models from two salivary gland cancer patients. Cellular liquid biopsy‐derived information enabled molecular genetic assessment of systemic disease heterogeneity and functional testing for therapy selection in both salivary gland cancer patients, which may provide a paradigm for other rare cancers.

Purpose The optimal time to initiation of adjuvant chemotherapy (TTAC) for triple negative breast cancer (TNBC) patients is unclear. This study evaluates the association between TTAC and survival in TNBC patients. Methods We conducted a retrospective study using data from a cohort of TNBC patients diagnosed between January 1, 2010 to December 31, 2018, registered in the Tumor Centre Regensburg was conducted. Data included demographics, pathology, treatment, recurrence and survival. TTAC was defined as days from primary surgery to first dose of adjuvant chemotherapy. The Kaplan–Meier method was used to evaluate impact of TTAC on overall survival (OS) and 5-year OS. Results A total of 245 TNBC patients treated with adjuvant chemotherapy and valid TTAC data were included. Median TTAC was 29 days. The group receiving systemic therapy within 22 to 28 days after surgery had the most favorable outcome, with median OS of 10.2 years. Groups receiving systemic therapy between 29–35 days, 36–42 days, and more than 6 weeks after surgery had significantly decreased median survival, with median OS of 8.3 years, 7.8 years, and 6.9 years, respectively. Patients receiving therapy between 22–28 days had significantly better survival compared to those receiving therapy between 29–35 days (p = 0.043), and patients receiving therapy after 22–28 days also demonstrated significantly better survival compared to those receiving therapy after more than 43 days (p = 0.033). Conclusion Timing of adjuvant systemic therapy can influence OS in TNBC patients. Efforts should be made to avoid unnecessary delays in administering chemotherapy to ensure timely initiation of systemic therapy and optimize patient outcomes.

Purpose For patients with triple negative breast cancer (TNBC), the optimal time to initiate neoadjuvant chemotherapy (TTNC) is unknown. This study evaluates the association between TTNC and survival in patients with early TNBC. Methods A retrospective study using data from of a cohort of TNBC patients diagnosed between January 1, 2010 to December 31, 2018 registered in the Tumor Centre Regensburg was performed. Data included demographics, pathology, treatment, recurrence, and survival. Interval to treatment was defined as days from pathology diagnosis of TNBC to first dose of neoadjuvant chemotherapy (NACT). The Kaplan–Meier and Cox regression methods were used to evaluate the impact of TTNC on overall survival (OS) and 5 year OS. Results A total of 270 patients were included. Median follow up was 3.5 years. The 5-year OS estimates according to TTNC were 77.4%, 66.9%, 82.3%, 80.6%, 88.3%, 58.3%, 71.1% and 66.7% in patients who received NACT within 0–14, 15–21, 22–28, 29–35, 36–42, 43–49, 50–56 and > 56 days after diagnosis. Patients who received systemic therapy early had the highest estimated mean OS of 8.4 years, while patients who received systemic therapy after more than 56 days survived an estimated 3.3 years. Conclusion The optimal time interval between diagnosis and NACT remains to be determined. However, starting NACT more than 42 days after diagnosis of TNBC seems to reduce survival. Therefore, it is strongly recommended to carry out the treatment in a certified breast center with appropriate structures, in order to enable an adequate and timely care.

Purpose Endometrial cancer (EC) is one of the most common malignancies among women in western countries. This study aimed to assess data on patient treatment in Germany throughout two decades to evaluate the development and effect of surgery, radiation, and chemotherapy. Methods This retrospective registry study included 34,349 EC patients diagnosed between 2000 and 2020. Patients were classified into five risk groups. Overall survival was analyzed by Kaplan–Meier method as well as univariable and multivariable Cox regression to evaluate risk factors and treatment options. Results Over the study period, minimal invasive surgery was used more often compared to open surgery and was associated with better overall survival. Patients with advanced EC were more likely to receive multimodal therapy. Patients with intermediate risk EC had a good prognosis upon surgery, which further improved when radiotherapy was added. High-risk patients showed poorer prognosis but clearly benefited from additional radiotherapy. Survival of elderly high-risk patients with a non-endometrioid histology was improved when chemotherapy was added to surgery and radiotherapy. Conclusion Our study includes a large analysis of data from German clinical cancer registries on the care of endometrial cancer during two decades. We observed an increase of minimal invasive surgery. There is evidence that minimal invasive surgery is not inferior to open surgery. Adjuvant radio- and chemotherapy further improves survival depending on risk group and age.

Phospho- and sphingolipids are crucial cellular and intracellular compounds. These lipids are required for active transport, a number of enzymatic processes, membrane formation, and cell signalling. Disruption of their metabolism leads to several diseases, with diverse neurological, psychiatric, and metabolic consequences. A large number of phospholipid and sphingolipid species can be detected and measured in human plasma. We conducted a meta-analysis of five European family-based genome-wide association studies (N = 4034) on plasma levels of 24 sphingomyelins (SPM), 9 ceramides (CER), 57 phosphatidylcholines (PC), 20 lysophosphatidylcholines (LPC), 27 phosphatidylethanolamines (PE), and 16 PE-based plasmalogens (PLPE), as well as their proportions in each major class. This effort yielded 25 genome-wide significant loci for phospholipids (smallest P-value = 9.88×10(-204)) and 10 loci for sphingolipids (smallest P-value = 3.10×10(-57)). After a correction for multiple comparisons (P-value<2.2×10(-9)), we observed four novel loci significantly associated with phospholipids (PAQR9, AGPAT1, PKD2L1, PDXDC1) and two with sphingolipids (PLD2 and APOE) explaining up to 3.1% of the variance. Further analysis of the top findings with respect to within class molar proportions uncovered three additional loci for phospholipids (PNLIPRP2, PCDH20, and ABDH3) suggesting their involvement in either fatty acid elongation/saturation processes or fatty acid specific turnover mechanisms. Among those, 14 loci (KCNH7, AGPAT1, PNLIPRP2, SYT9, FADS1-2-3, DLG2, APOA1, ELOVL2, CDK17, LIPC, PDXDC1, PLD2, LASS4, and APOE) mapped into the glycerophospholipid and 12 loci (ILKAP, ITGA9, AGPAT1, FADS1-2-3, APOA1, PCDH20, LIPC, PDXDC1, SGPP1, APOE, LASS4, and PLD2) to the sphingolipid pathways. In large meta-analyses, associations between FADS1-2-3 and carotid intima media thickness, AGPAT1 and type 2 diabetes, and APOA1 and coronary artery disease were observed. In conclusion, our study identified nine novel phospho- and sphingolipid loci, substantially increasing our knowledge of the genetic basis for these traits.

Sphingolipids have essential roles as structural components of cell membranes and in cell signalling, and disruption of their metabolism causes several diseases, with diverse neurological, psychiatric, and metabolic consequences. Increasingly, variants within a few of the genes that encode enzymes involved in sphingolipid metabolism are being associated with complex disease phenotypes. Direct experimental evidence supports a role of specific sphingolipid species in several common complex chronic disease processes including atherosclerotic plaque formation, myocardial infarction (MI), cardiomyopathy, pancreatic beta-cell failure, insulin resistance, and type 2 diabetes mellitus. Therefore, sphingolipids represent novel and important intermediate phenotypes for genetic analysis, yet little is known about the major genetic variants that influence their circulating levels in the general population. We performed a genome-wide association study (GWAS) between 318,237 single-nucleotide polymorphisms (SNPs) and levels of circulating sphingomyelin (SM), dihydrosphingomyelin (Dih-SM), ceramide (Cer), and glucosylceramide (GluCer) single lipid species (33 traits); and 43 matched metabolite ratios measured in 4,400 subjects from five diverse European populations. Associated variants (32) in five genomic regions were identified with genome-wide significant corrected p-values ranging down to 9.08x10(-66). The strongest associations were observed in or near 7 genes functionally involved in ceramide biosynthesis and trafficking: SPTLC3, LASS4, SGPP1, ATP10D, and FADS1-3. Variants in 3 loci (ATP10D, FADS3, and SPTLC3) associate with MI in a series of three German MI studies. An additional 70 variants across 23 candidate genes involved in sphingolipid-metabolizing pathways also demonstrate association (p = 10(-4) or less). Circulating concentrations of several key components in sphingolipid metabolism are thus under strong genetic control, and variants in these loci can be tested for a role in the development of common cardiovascular, metabolic, neurological, and psychiatric diseases.

The prolonged life span of chronic lymphocytic leukemia (CLL) cells in vivo is assumed to depend on the surrounding microenvironment since this biologic feature is lost in vitro. We studied here the molecular interactions between CLL cells and their surrounding stroma to identify factors that help CLL cells to resist apoptosis. Sorted CLL cells from 21 patients were cultured in vitro on allogenous, normal bone marrow stromal cells (BMSCs) in the presence/absence of CD40 ligand or in culture medium alone. Surface and mRNA expression of interaction molecules, cytokine production, and apoptosis rate was measured by flow cytometric, real-time PCR and standard immunologic assays. The interaction between CLL cells and BMSCs rescued CLL cells from apoptosis. BMSCs co-cultured with CLL cells showed a strong increase in IL-8 and IL-6 secretion and up-regulated the expression of ICAM-1 and CD40 mRNA. The mRNA expression of CXCL12 and VCAM1 remained unchanged. In turn, CLL cells in interaction with BMSCs significantly up-regulated the expression of CD18 and CD49d that are ligands for the critical adhesion molecules on BMSCs. As a validation of the in vitro data, we found a significant higher expression of CD49d on CLL cells in bone marrow aspirates compared to peripheral blood CLL cells in patient samples. Up-regulation of adhesion molecules and their ligands in CLL–BMSCs interaction along with the increased cytokine production of BMSCs indicate a strong effect of CLL cells on BMSCs in favor of their apoptosis resistance.

Background Genome-wide association studies (GWAS) have identified many common single nucleotide polymorphisms (SNPs) that associate with clinical phenotypes, but these SNPs usually explain just a small part of the heritability and have relatively modest effect sizes. In contrast, SNPs that associate with metabolite levels generally explain a higher percentage of the genetic variation and demonstrate larger effect sizes. Still, the discovery of SNPs associated with metabolite levels is challenging since testing all metabolites measured in typical metabolomics studies with all SNPs comes with a severe multiple testing penalty. We have developed an automated workflow approach that utilizes prior knowledge of biochemical pathways present in databases like KEGG and BioCyc to generate a smaller SNP set relevant to the metabolite. This paper explores the opportunities and challenges in the analysis of GWAS of metabolomic phenotypes and provides novel insights into the genetic basis of metabolic variation through the re-analysis of published GWAS datasets. Results Re-analysis of the published GWAS dataset from Illig et al. (Nature Genetics, 2010) using a pathway-based workflow ( http://www.myexperiment.org/packs/319.html ), confirmed previously identified hits and identified a new locus of human metabolic individuality, associating Aldehyde dehydrogenase family1 L1 ( ALDH1L1 ) with serine/glycine ratios in blood. Replication in an independent GWAS dataset of phospholipids (Demirkan et al., PLoS Genetics, 2012) identified two novel loci supported by additional literature evidence: GPAM ( Glycerol-3 phosphate acyltransferase) and CBS (Cystathionine beta-synthase). In addition, the workflow approach provided novel insight into the affected pathways and relevance of some of these gene-metabolite pairs in disease development and progression. Conclusions We demonstrate the utility of automated exploitation of background knowledge present in pathway databases for the analysis of GWAS datasets of metabolomic phenotypes. We report novel loci and potential biochemical mechanisms that contribute to our understanding of the genetic basis of metabolic variation and its relationship to disease development and progression.