Acidosis-mediated increase in IFN-γ-induced PD-L1 expression on cancer cells as an immune escape mechanism in solid tumors.

Immune checkpoint inhibitors have revolutionized cancer therapy, yet the efficacy of these treatments is often limited by the heterogeneous and hypoxic tumor microenvironment (TME) of solid tumors. In the TME, programmed death-ligand 1 (PD-L1) expression on cancer cells is mainly regulated by Interferon-gamma (IFN-γ), which induces T cell exhaustion and enables tumor immune evasion. In this study, we demonstrate that acidosis, a common characteristic of solid tumors, significantly increases IFN-γ-induced PD-L1 expression on aggressive cancer cells, thus promoting immune escape. Using preclinical models, we found that acidosis enhances the genomic expression and phosphorylation of signal transducer and activator of transcription 1 (STAT1), and the translation of STAT1 mRNA by eukaryotic initiation factor 4F (elF4F), resulting in an increased PD-L1 expression. We observed this effect in murine and human anti-PD-L1-responsive tumor cell lines, but not in anti-PD-L1-nonresponsive tumor cell lines. In vivo studies fully validated our in vitro findings and revealed that neutralizing the acidic extracellular tumor pH by sodium bicarbonate treatment suppresses IFN-γ-induced PD-L1 expression and promotes immune cell infiltration in responsive tumors and thus reduces tumor growth. However, this effect was not observed in anti-PD-L1-nonresponsive tumors. In vivo experiments in tumor-bearing IFN-γ-/- mice validated the dependency on immune cell-derived IFN-γ for acidosis-mediated cancer cell PD-L1 induction and tumor immune escape. Thus, acidosis and IFN-γ-induced elevation of PD-L1 expression on cancer cells represent a previously unknown immune escape mechanism that may serve as a novel biomarker for anti-PD-L1/PD-1 treatment response. These findings have important implications for the development of new strategies to enhance the efficacy of immunotherapy in cancer patients.

[German linguistic validation of the BODY-Q: standardised PRO instrument after bariatric and bodycontouring surgery]. / Deutschsprachige Validierung des Body-Q ­ standardisiertes PRO-Messinstrument nach bariatrischen und körperformenden Eingriffen.

One of the most important parts of result evaluation in plastic surgery, especially postbariatric and body-contouring surgery, is the appraisal of changes in patients' quality of life after treatment. Standardised assessments of patient-reported outcomes (PROs) are indispensable.BODY-Q (A. Klassen et al.) is a multifaceted, valid PRO instrument comprising a total of 26 scales for the evaluation of multiple factors of everyday life in order to quantify well-being, satisfaction and functionality. Each scale contains 4-10 statements, which have to be rated by patients.The BODY-Q was created pursuant to ISPOR (International Society for Pharmacoeconomics and Outcomes Research) standards and subjected to psychometric tests with great results. It is considered a standard PRO instrument for quality of life in postbariatric and body-contouring surgery.In order to expand the applicability of standardised questionnaires, ISPOR established linguistic validation guidelines, which have been applied to the BODY-Q in Dutch, Danish, Finnish and Polish.In this study, German linguistic validation was completed applying the standardised guidelines. First the BODY-Q was translated in consensus with medical expertise. Then a certified translator produced a backwards translation, which was commented on by the author. After appropriate changes were made in due consideration of these comments, interviews with patients were conducted to remove any sources of content-related misconception. Finally, the translated version was applied on patients. All the scales were translated to an easily understandable questionnaire reliable in form and content. An international collaboration aiming to centralise the results has started. Further linguistic validation procedures in other languages have been initiated, and an international cohort structure is planned to be established for body-contouring procedures in order to systematically improve treatment quality in plastic surgery.

Diagnostic relevance of a novel multiplex immunoassay panel in breast cancer.

Multiple factors contribute to the development and progression of breast cancer. Markers of tumor growth and invasion, cell death, immune activation, and angiogenesis can be assessed in parallel by a novel multiplex immunoassay panel. The diagnostic performance of a multiplex cancer biomarker magnetic bead panel comprising 24 tumor associated parameters was evaluated in sera of 154 women including 77 patients with breast cancer, 10 with precancerous lesions, 31 with benign breast diseases, and 36 healthy controls. Marker levels were log-transformed for variance stabilization. Significance testing was done using t-test or Wilcoxon rank-sum test with correction of p values for multiple testing. Furthermore, receiver operating characteristic analyses were performed. Serum levels of several biomarkers were significantly (p ≤ 0.001) higher in cancer patients than in healthy controls, particularly alpha-fetoprotein, cancer antigen 15-3, cancer antigen 19-9, migration inhibitory factor, carcinoembryonic antigen, cancer antigen 125, hepatocyte growth factor, soluble Fas, tumor necrosis factor-α, stem cell factor, and osteopontin. As most markers were also elevated in benign breast diseases, only cancer antigen 15-3 showed significant differences to cancer patients (p ≤ 0.001). The resulting areas under the curve in receiver operating characteristic curves for discrimination between benign and malignant breast diseases achieved 0.71 with a sensitivity of 33.8% at 95% specificity. Multiplexing enables parallel analysis of different biomarker classes for cancer detection. Established cancer antigen 15-3 proved to be most relevant for differential diagnosis.

Diagnostic Performance of a Novel Multiplex Immunoassay in Colorectal Cancer.

BACKGROUND/AIM: We evaluated the diagnostic performance of a newly-launched magnetic bead-based multiplex immunoassay panel including cancer, apoptotic, immunological and angiogenesis biomarkers for differential diagnosis of colorectal cancer (CRC). PATIENTS AND METHODS: Serum samples of 106 individuals comprising of 35 patients with CRC (23 colon cancer, 12 rectal cancer), 20 with respective benign colorectal diseases and 51 healthy controls were analyzed by the Milliplex™ MAP Human Circulating Cancer Biomarker Panel 1 run on the Bio-Plex™ 200 System. RESULTS: IL-8, CEA, HGF, TNFα, CYFRA 21-1, OPN, TGFα, CA 19-9, CA 125, AFP and sFas showed significantly higher levels in cancer samples compared to healthy controls. It is noteworthy that comparing CRC and benign colorectal disease samples, many immunological and cell death markers were elevated as well. Exclusively, six markers were distinguished significantly between both groups: CEA showed the best performance in differential diagnosis reaching an AUC of 0.859 in ROC curve followed by CA 19-9, CYFRA 21-1, IL-8, CA 125 and OPN reaching AUCs between 0.696 and 0.744. Correlation with tumor stage was found for CEA, sFas and CYFRA 21-1. Finally marker scores were assembled showing that a combination of CEA and CA 19-9 had a higher AUC (0.893) compared to the biomarkers alone. CONCLUSION: Differential diagnosis of CRC can be improved by new biomarker classes and their combination assessed by novel multiplex immunoassay.

Methodical and pre-analytical characteristics of a multiplex cancer biomarker immunoassay.

AIM: To test the methodical and pre-analytical performance of a new multiplex cancer biomarker panel using magnetic beads. METHODS: The MILLIPLEX(®) MAP Human Circulating Cancer Biomarker Magnetic Bead Panel 1 comprises the tumor markers carcinoembryonic antigen, alpha-fetoprotein, total prostate-specific antigen, cancer antigen 15-3, cancer antigen 19-9, cancer antigen 125, cytokeratine 19-fragment, ß-human chorionic gonadotropin, human epididymis protein 4, osteopontin, prolactin, the cell death and angiogenesis markers soluble Fas, soluble Fas-ligand, tumor necrosis factor related apoptosis-inducing ligand, vascular endothelial growth factor and the immunological markers interleukin-6 (IL-6), IL-8, tumor necrosis factor-α, transforming growth factor α, fibroblast growth factor-2, macrophage migration inhibitory factor, leptin, hepatocyte growth factor, and stem cell factor. We determined intra- and inter-assay imprecision as well as dilution linearity using quality controls and serum pools. Furthermore, the stability of the 24 biomarkers examined in this panel was ascertained by testing the influence of different storage temperatures and time span before centrifugation. RESULTS: For all markers measured in the synthetic internal quality controls, the intra-assay imprecision ranged between 2.26% and 9.41%, while for 20 of 24 measured markers in the physiological serum pools, it ranged between 1.68% and 12.87%. The inter-assay imprecision ranged between 1.48%-17.12% for 23 biomarkers in synthetic, and between 4.59%-23.88% for 18 biomarkers in physiological quality controls. Here, single markers with very low concentration levels had increased imprecision rates. Dilution linearity was acceptable (70%-130% recovery) for 20 biomarkers. Regarding pre-analytical influencing factors, most markers were stable if blood centrifugation was delayed or if serum was stored for up to 24 h at 4 °C and 25 °C after centrifugation. Comparable results were obtained in serum and plasma for most markers. However, great changes were observed for single markers. CONCLUSION: MILLIPLEX(®) MAP Human Circulating Cancer Biomarker Magnetic Bead Panel 1 assay is a stable and precise method for detection of most biomarkers included in the kit. However, single markers have to be interpreted with care.