Alexander Quaas

Natural Killer Group 2D Ligand Depletion Reconstitutes Natural Killer Cell Immunosurveillance of Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a highly heterogeneous and aggressive tumor originating from the epithelial lining of the upper aero-digestive tract accounting for 300,000 annual deaths worldwide due to failure of current therapies. The natural killer group 2D (NKG2D) receptors on natural killer (NK) cells and several T cell subsets play an important role for immunosurveillance of HNSCC and are thus targeted by tumor immune evasion strategies in particular by shedding of various NKG2D ligands (NKG2DLs). Based on plasma and tumor samples of 44 HNSCC patients, we found that despite compositional heterogeneity the total plasma level of NKG2DLs correlates with NK cell inhibition and disease progression. Strikingly, based on tumor spheroids and primary tumors of HNSCC patients, we found that NK cells failed to infiltrate HNSCC tumors in the presence of high levels of NKG2DLs, demonstrating a novel mechanism of NKG2DL-dependent tumor immune escape. Therefore, the diagnostic acquisition of the plasma level of all NKG2DLs might be instrumental for prognosis and to decipher a patient cohort, which could benefit from restoration of NKG2D-dependent tumor immunosurveillance. Along these lines, we could show that removal of shed NKG2DLs (sNKG2DLs) from HNSCC patients’ plasma restored NK cell function in vitro and in individual patients following surgical removal of the primary tumor. In order to translate these findings into a therapeutic setting, we performed a proof-of-concept study to test the efficacy of adsorption apheresis of sNKG2DLs from plasma after infusion of human MICA in rhesus monkeys. Complete removal of MICA was achieved after three plasma volume exchanges. Therefore, we propose adsorption apheresis of sNKG2DLs as a future preconditioning strategy to improve the efficacy of autologous and adoptively transferred immune cells in cellular cancer immunotherapy.

Dysfunction of hepatic regulatory T cells in experimental sclerosing cholangitis is related to IL-12 signaling

BACKGROUND & AIMS Reduced numbers of regulatory T cells (Treg) have been reported in patients with primary sclerosing cholangitis (PSC); therefore, Treg expansion might serve as a therapeutic approach. Here, we explored whether treatment with IL-2/IL-2 monoclonal antibody complex (IL-2/IL-2Ab complex) could provide in vivo Treg expansion and treatment of experimental sclerosing cholangitis. METHODS Treg were expanded by repeated injection of IL-2/IL-2Ab complex in mouse models of cholangitis (Mdr2-/-, DDC) or colitis (dextran sulfate sodium [DSS]) as control. In vitro suppressive capacity and gene expression were analyzed in isolated hepatic and splenic Treg. RESULTS In vivo expansion resulted in a 5-fold increase in hepatic Treg, which localized within the inflamed portal tracts. However, although Treg expansion was associated with reduced pro-inflammatory IL-17 and increased anti-inflammatory IL-10 production by hepatic lymphocytes, the severity of cholangitis was not reduced. In contrast, DSS-induced colitis could be improved by Treg expansion, suggesting a selectively reduced functionality of intrahepatic Treg. Indeed, hepatic Treg manifested reduced Foxp3 expression and reduced suppressive capacity compared to splenic Treg. Hepatic Treg dysfunction could be linked to increased IL-12 signaling due to an upregulation of the IL-12 receptor. Accordingly, IL-12 receptor beta 2 knockout mice (IL-12rb2-/-) were able to maintain hepatic Treg functionality. CONCLUSIONS Hepatic Treg expanded in vivo failed to improve the course of cholangitis, which was related to the effects of hepatic IL-12 on Treg. Therefore, neutralization of IL-12 should be considered as part of treatment strategies targeting Treg in sclerosing cholangitis. LAY SUMMARY Primary sclerosing cholangitis (PSC) is associated with a paucity of regulatory T cells (Treg) that have a particular ability to control immune responses; therefore, in vivo expansion of Treg might serve as a treatment of cholangitis. However, in a mouse model of PSC, we show that Treg enrichment in the liver was not sufficient to provide effective control of cholangitis, as the suppressive functionality of hepatic Treg was significantly limited by IL-12 signals. Thus, neutralization of IL-12 should be considered as part of treatment strategies to improve the efficacy of Treg-based treatments for liver diseases. Data accession number: GSE 87898.

Ultrasound-guided core needle biopsies for workup of lymphadenopathy and lymphoma

For the histopathological diagnosis of lymphoma, lymph node excision biopsies are regarded as standard of care. In contrast, for the diagnosis of carcinoma and deep‐seated tumors, core needle biopsies (CNBs) are accepted as a sufficient sampling method. We evaluated a diagnostic algorithm for peripheral lymphadenopathy starting with ultrasound‐guided CNB followed by excisional biopsy in ambiguous cases.

MDM2 and CDK4 amplifications are rare events in salivary duct carcinomas

Salivary duct carcinoma (SDC) is an aggressive adenocarcinoma of the salivary glands associated with poor clinical outcome. SDCs are known to carry TP53 mutations in about 50%, however, only little is known about alternative pathogenic mechanisms within the p53 regulatory network. Particularly, data on alterations of the oncogenes MDM2 and CDK4 located in the chromosomal region 12q13-15 are limited in SDC, while genomic rearrangements of the adjacent HMGA2 gene locus are well documented in subsets of SDCs. We here analyzed the mutational status of the TP53 gene, genomic amplification of MDM2, CDK4 and HMGA2 rearrangement/amplification as well as protein expression of TP53 (p53), MDM2 and CDK4 in 51 de novo and ex pleomorphic adenoma SDCs. 25 of 51 cases were found to carry TP53 mutations, associated with extreme positive immunohistochemical p53 staining levels in 13 cases. Three out of 51 tumors had an MDM2 amplification, one of them coinciding with a CDK4 amplification and two with a HMGA2 rearrangement/amplification. Two of the MDM2 amplifications occurred in the setting of a TP53 mutation. Two out of 51 cases showed a CDK4 amplification, one synchronously being MDM2 amplified and the other one displaying concurrent low copy number increases of both, MDM2 and HMGA2. In summary, we here show that subgroups of SDCs display genomic amplifications of MDM2 and/or CDK4, partly in association with TP53 mutations and rearrangement/amplification of HMGA2. Further research is necessary to clarify the role of chromosomal region 12q13-15 alterations in SDC tumorigenesis and their potential prognostic and therapeutic relevance.

MDM2 gene amplification in esophageal carcinoma

Esophageal cancer (EC) is one of the most common malignancies diagnosed in the Western world with an increasing incidence noted for esophageal adenocarcinoma (EAC). Despite improvements in staging, surgical procedures and postoperative treatments, the overall survival of patients with EC remains low. Murine double minute‑2 (MDM2) acts as an oncogene by inducing the degradation of the tumor‑suppressor protein TP53. In order to evaluate the MDM2 gene amplification status in EAC and squamous cell carcinoma (SCC), we established a quantitative PCR (qPCR) assay, screening a total of 127 esophageal carcinoma cases for MDM2 amplification. Esophageal carcinoma cases with enhanced MDM2 gene copy numbers were further analyzed by fluorescence in situ hybridisation (FISH) and MDM2 immunostaining. Among a total of 23 specimens (18%), identified by qPCR to possess elevated MDM2 gene copy numbers, one third (6.3%) showed a cluster‑like fluorescence pattern by FISH analyses and marked MDM2 protein immunostaining. MDM2 gene amplifications did not correlate with the occurrence of TP53 mutations. Due to the high therapeutic relevance of MDM2 overexpression, but the high cost of FISH, we suggest a primary screening of MDM2 copy number variations by qPCR, followed by detailed FISH analysis of the identified ECs.

Chirurgische Therapie pulmonaler Metastasen des malignen Melanoms

Results of previous studies question the benefits of pulmonary surgery in patients with pulmonary metastases from malignant melanoma. A systematic literature search and analysis of articles published since 1 January 2000 was carried out to investigate the advantages of metastasectomy and alternative forms of therapy. Patients reached a median survival time of 17-40 months and 5-year survival rates between 18% and 39.4% after metastasectomy. Intrathoracic recurrence occurred in 30 % of patients but could be successfully treated with re-operations in some cases. Various monoclonal antibodies are currently available and achieve a median survival time of up to 17 months. Pulmonary metastasectomy is the treatment of choice in selected patients; however, in the future the benefits should be revalidated in comparison with pharmaceuticals of the current generation.

Surgical therapy for pulmonary metastases from malignant melanoma

Results of previous studies question the benefits of pulmonary surgery in patients with pulmonary metastases from malignant melanoma. A systematic literature search and analysis of articles published since 1 January 2000 was carried out to investigate the advantages of metastasectomy and alternative forms of therapy. Patients reached a median survival time of 17-40 months and 5-year survival rates between 18% and 39.4% after metastasectomy. Intrathoracic recurrence occurred in 30 % of patients but could be successfully treated with re-operations in some cases. Various monoclonal antibodies are currently available and achieve a median survival time of up to 17 months. Pulmonary metastasectomy is the treatment of choice in selected patients; however, in the future the benefits should be revalidated in comparison with pharmaceuticals of the current generation.

Chirurgische Therapie pulmonaler Metastasen von Kopf-Hals-Tumoren

Pulmonary metastasectomy is an established procedure in oncological therapeutic concepts. A systematic literature search and an analysis of all studies published since 01.01.2000 should evaluate the advantage of pulmonary metastasectomy for patients with primary head and neck cancer. Lung metastases develop in 1.9-13% of head and neck cancer patients. Following metastasectomy, patients reach a median survival of 9.5-78 months and 5-year survival rates of up to 58% are achieved. Intrathoracic recurrence occurs in 18.4-81.8% of patients, selected instances of which can be successfully treated by remetastasectomy. Patients with squamous cell carcinoma have the worst prognosis, but could also become long-term survivors (≥ 60 months). Pulmonary metastasectomy is frequently the only potentially curative therapeutic approach and offers a better long-term survival than nonsurgical therapies. Lung metastasectomy is thus the treatment of choice in selected patients with pulmonary metastases from primary head and neck cancer.

Loss of membranous VEGFR1 expression is associated with an adverse phenotype and shortened survival in breast cancer

Angiogenesis is a key process in tumor growth and progression, which is controlled by vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs). In order to better understand the prevalence and prognostic value of VEGFR1 expression in breast cancer, a tissue microarray containing >2,100 breast cancer specimens, with clinical follow-up data, was analyzed by immunohistochemistry using an antibody directed against the membrane-bound full-length receptor protein. The results demonstrated that membranous VEGFR1 staining was detected in all (5 of 5) normal breast specimens. In carcinoma specimens, membranous staining was negative in 3.1%, weak in 6.3%, moderate in 10.9%, and strong in 79.7% of the 1,630 interpretable tissues. Strong staining was significantly associated with estrogen receptor and progesterone receptor expression, but was inversely associated with advanced tumor stage (P=0.0431), high Bloom-Richardson-Ellis Score for Breast Cancer grade and low Ki67 labeling index (both P<0.0001). Cancers with moderate to strong (high) VEGFR1 expression were associated with significantly improved overall survival, as compared with tumors exhibiting negative or weak (low) expression (P=0.0015). This association was also detected in the subset of nodal-positive cancers (P=0.0018), and in the subset of 185 patients who had received tamoxifen as the sole therapy (P=0.001). In conclusion, these data indicated that membrane-bound VEGFR1 is frequently expressed in normal and cancerous breast epithelium. In addition, reduced or lost VEGFR1 expression may serve as a marker for poor prognosis in patients with breast cancer, who might not optimally benefit from endocrine therapy.

Surgical therapy of lung metastases from head and neck cancer

Pulmonary metastasectomy is an established procedure in oncological therapeutic concepts. A systematic literature search and an analysis of all studies published since 01.01.2000 should evaluate the advantage of pulmonary metastasectomy for patients with primary head and neck cancer. Lung metastases develop in 1.9-13% of head and neck cancer patients. Following metastasectomy, patients reach a median survival of 9.5-78 months and 5-year survival rates of up to 58% are achieved. Intrathoracic recurrence occurs in 18.4-81.8% of patients, selected instances of which can be successfully treated by remetastasectomy. Patients with squamous cell carcinoma have the worst prognosis, but could also become long-term survivors (≥ 60 months). Pulmonary metastasectomy is frequently the only potentially curative therapeutic approach and offers a better long-term survival than nonsurgical therapies. Lung metastasectomy is thus the treatment of choice in selected patients with pulmonary metastases from primary head and neck cancer.