Novel morphological and genetic features of fumarate hydratase deficient renal cell carcinoma in HLRCC syndrome patients with a tailored therapeutic approach.

The hereditary leiomyomatosis and renal cell carcinoma syndrome (HLRCC) is defined by germline mutations in the fumarate hydratase (FH) gene and associated with leiomyomas and aggressive renal cell carcinomas with FH deficiency. Here, we comprehensively characterize two new patients with HLRCC syndrome on a morphological, immunohistochemical and genetic level. The patients developed aggressive HLRCC syndrome-associated RCCs, uterine leiomyomas and dermal leiomyomas. One HLRCC syndrome-associated RCC exhibited an unusual morphology with accumulation of "colloid-like" cytoplasmic inclusions, which might serve as a novel sentinel feature to trigger further testing. This case showed partially retained FH expression, initially hampering correct diagnosis. Comprehensive next-generation sequencing analyses of HLRCC syndrome-associated RCC and leiomyomas in our patients revealed divergent genetic changes in the FH gene in different tumors from the same patient. While all leiomyomas (uterine and cutaneous) showed a FH loss of heterozygosity (LOH) as a wildtype allele inactivating event, one HLRCC-RCC showed a second, undescribed NM_000143.3; c.947C>T; p.Ala316Val FH mutation accompanying the preexisting splice site mutation c.378+2T>C. In the other HLRCC syndrome-associated RCC, the FH mutation (NM_000143.3; c.462T>G; p.Asn154Lys with a somatic LOH) represents another variant of unknown significance that we link to HLRCC - and thus classify as likely pathogenic. Due to the specific diagnosis of metastatic HLRCC syndrome-associated RCC, both cases were treated in first line with bevacizumab/erlotinib and showed remarkable and long lasting responses. These findings allow new morphological and molecular insights into the biology of the HLRCC syndrome, corroborate the "second hit" hypothesis of tumor formation in HLRCC patients and may promote a distinct therapeutic approach.

Mobilization of Hematopoietic Progenitor Cells with Standard- or Reduced-Dose Filgrastim after Vinorelbine in Multiple Myeloma Patients: A Randomized Prospective Single-Center Phase II Study.

Vinorelbine combined with filgrastim at a dose of 10 µg/kg of body weight (BW) per day is a reliable and well-tolerated regimen for mobilization of hematopoietic progenitor cells (HPCs) in patients with multiple myeloma. This prospective, randomized, phase II study was initiated to assess the feasibility of a reduced filgrastim dosage. Vinorelbine was combined with either standard-dose filgrastim (10 µg/kg BW per day) or reduced-dose filgrastim (5 µg/kg BW per day). Leukapheresis sessions were planned to start at day 8 and were continued until the predefined target amount of 4 × 106 HPCs/kg BW was collected. The study demonstrated the feasibility of vinorelbine combined with reduced daily filgrastim with a mean of 1.29 leukapheresis sessions necessary per patient (95% confidence interval, .95 to 1.7). All patients could start leukapheresis as planned at day 8, and the collection success rate was 100% for the whole patient collective after a maximum of 2 leukapheresis sessions. No statistically significant differences with regard to the amount of HPCs collected between the 2 groups were observed (P = .99). Accordingly, no differences were seen with regard to length of hospitalization for autotransplant (P = .34) and duration of neutrophil (P = .93) and platelet engraftment (P = .42). Patients receiving reduced-dose filgrastim reported significantly lower peak pain values in a numeric analogue scale (P = .01), and the costs were significantly lower than in patients undergoing standard-dose chemomobilization (P = .001). Vinorelbine 35 mg/m2 plus filgrastim 5 µg/kg BW once per day until completion of HPC collection is feasible and appears to be advantageous with respect to the severity of pain intensity and treatment costs.

Efficacious and save use of biosimilar filgrastim for hematopoietic progenitor cell chemo-mobilization with vinorelbine in multiple myeloma patients.

Biosimilars are increasingly being licensed as equipotent drugs, although efficacy and safety data are not available for all clinical indications. Accordingly, the efficacy of the biosimilar filgrastim Zarzio® combined with vinorelbine for chemo-mobilization of CD34+ hematopoietic progenitor cells (HPC) in patients with multiple myeloma has not been evaluated yet. We compared the efficacy of vinorelbine combined with this biosimilar filgrastim for HPC mobilization to vinorelbine plus original filgrastim (Neupogen®). Overall, 105 multiple myeloma patients received vinorelbine 35 mg/m2 intravenously on day 1 and either original filgrastim (n = 61;58%) or biosimilar filgrastim (n = 44;42%) at a dose of 5 µg per kg body weight (BW) twice daily subcutaneously starting day 4 until the end of the collection procedure. Leukapheresis was scheduled to start on day 8 and performed for a maximum of three consecutive days until at least 4 × 106 HPC/kg BW were collected. All patients proceeded to leukapheresis. In 102 (97%) patients the leukapheresis sessions were started as planned at day 8. The median number of collected HPC was 7.3 × 106 /kg BW (0.2-18.3) with original filgrastim compared to 9 × 106 /kg BW (4.2-23.8) with the biosimilar filgrastim (P = 0.16). HPC collection was successful in 57 (93%) of 61 patients of the original group and in all 44 (100%) patients of the biosimilar group (P = 0.14). No differences were observed regarding side effects. Duration of neutrophil engraftment after autologous HPC transplantation was similar between the two groups (P = 0.17). Biosimilar and original filgrastim achieve comparable results in combination with vinorelbine regarding HPC mobilization and transplantation outcome in multiple myeloma patients. J. Clin. Apheresis 32:21-26, 2017. © 2016 Wiley Periodicals, Inc.

Characterization of VHL missense mutations in sporadic clear cell renal cell carcinoma: hotspots, affected binding domains, functional impact on pVHL and therapeutic relevance.

BACKGROUND: The VHL protein (pVHL) is a multiadaptor protein that interacts with more than 30 different binding partners involved in many oncogenic processes. About 70 % of clear cell renal cell carcinoma (ccRCC) have VHL mutations with varying impact on pVHL function. Loss of pVHL function leads to the accumulation of Hypoxia Inducible Factor (HIF), which is targeted by current targeted treatments. In contrast to nonsense and frameshift mutations that highly likely nullify pVHL multipurpose functions, missense mutations may rather specifically influence the binding capability of pVHL to its partners. The affected pathways may offer predictive clues to therapy and response to treatment. In this study we focused on the VHL missense mutation pattern in ccRCC, and studied their potential effects on pVHL protein stability and binding partners and discussed treatment options. METHODS: We sequenced VHL in 360 sporadic ccRCC FFPE samples and compared observed and expected frequency of missense mutations in 32 different binding domains. The prediction of the impact of those mutations on protein stability and function was assessed in silico. The response to HIF-related, anti-angiogenic treatment of 30 patients with known VHL mutation status was also investigated. RESULTS: We identified 254 VHL mutations (68.3 % of the cases) including 89 missense mutations (35 %). Codons Ser65, Asn78, Ser80, Trp117 and Leu184 represented hotspots and missense mutations in Trp117 and Leu 184 were predicted to highly destabilize pVHL. About 40 % of VHL missense mutations were predicted to cause severe protein malfunction. The pVHL binding domains for HIF1AN, BCL2L11, HIF1/2α, RPB1, PRKCZ, aPKC-λ/ι, EEF1A1, CCT-ζ-2, and Cullin2 were preferentially affected. These binding partners are mainly acting in transcriptional regulation, apoptosis and ubiquitin ligation. There was no correlation between VHL mutation status and response to treatment. CONCLUSIONS: VHL missense mutations may exert mild, moderate or strong impact on pVHL stability. Besides the HIF binding domain, other pVHL binding sites seem to be non-randomly altered by missense mutations. In contrast to LOF mutations that affect all the different pathways normally controlled by pVHL, missense mutations may be rather appropriate for designing tailor-made treatment strategies for ccRCC.

Efficacy of vinorelbine plus granulocyte colony-stimulation factor for CD34+ hematopoietic progenitor cell mobilization in patients with multiple myeloma.

We aimed to assess the efficacy of vinorelbine plus granulocyte colony-stimulating factor (G-CSF) for chemo-mobilization of CD34(+) hematopoietic progenitor cells (HPC) in patients with multiple myeloma and to identify adverse risk factors for successful mobilization. Vinorelbine 35 mg/m(2) was administered intravenously on day 1 in an outpatient setting. Filgrastim 5 µg/kg body weight (BW) was given twice daily subcutaneously from day 4 until the end of the collection procedure. Leukapheresis was scheduled to start on day 8 and be performed for a maximum of 3 consecutive days until at least 4 × 10(6) CD34(+) cells per kg BW were collected. Overall, 223 patients were mobilized and 221 (99%) patients proceeded to leukapheresis. Three (1.5%) patients required an unscheduled hospitalization after chemo-mobilization because of neutropenic fever and renal failure (n = 1), severe bone pain (n = 1), and abdominal pain with constipation (n = 1). In 211 (95%) patients, the leukaphereses were started as planned at day 8, whereas in 8 (3%) patients the procedure was postponed to day 9 and in 2 (1%) patients to day 10. In the great majority of patients (77%), the predefined amount of HPC could be collected with 1 leukapheresis. Forty-four (20%) patients needed a second leukapheresis, whereas only 6 (3%) patients required a third leukapheresis procedure. The median number of CD34(+) cells collected was 6.56 × 10(6) (range, .18 to 25.9 × 10(6)) per kg BW at the first day of leukapheresis and 7.65 × 10(6) (range, .18 to 25.9 × 10(6)) per kg BW in total. HPC collection was successful in 212 (95%) patients after a maximum of 3 leukaphereses. Patient age (P = .02) and prior exposition to lenalidomide (P < .001) were independent risk factors for a lower HPC amount collected in multiple regression analysis. Vinorelbine plus G-CSF enables a very reliable prediction of the timing of leukapheresis and results in successful HPC collection in 95% of the patients.

Treatment of malignant pleural mesothelioma by fibroblast activation protein-specific re-directed T cells.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is an incurable malignant disease, which results from chronic exposition to asbestos in at least 70% of the cases. Fibroblast activation protein (FAP) is predominantly expressed on the surface of reactive tumor-associated fibroblasts as well as on particular cancer types. Because of its expression on the cell surface, FAP is an attractive target for adoptive T cell therapy. T cells can be re-directed by retroviral transfer of chimeric antigen receptors (CAR) against tumor-associated antigens (TAA) and therefore represent a therapeutic strategy of adoptive immunotherapy. METHODS: To evaluate FAP expression immunohistochemistry was performed in tumor tissue from MPM patients. CD8+ human T cells were retrovirally transduced with an anti-FAP-F19-∆CD28/CD3ζ-CAR. T cell function was evaluated in vitro by cytokine release and cytotoxicity assays. In vivo function was tested with an intraperitoneal xenograft tumor model in immunodeficient mice. RESULTS: FAP was found to be expressed in all subtypes of MPM. Additionally, FAP expression was evaluated in healthy adult tissue samples and was only detected in specific areas in the pancreas, the placenta and very weakly for cervix and uterus. Expression of the anti-FAP-F19-∆CD28/CD3ζ-CAR in CD8+ T cells resulted in antigen-specific IFNγ release. Additionally, FAP-specific re-directed T cells lysed FAP positive mesothelioma cells and inflammatory fibroblasts in an antigen-specific manner in vitro. Furthermore, FAP-specific re-directed T cells inhibited the growth of FAP positive human tumor cells in the peritoneal cavity of mice and significantly prolonged survival of mice. CONCLUSION: FAP re-directed CD8+ T cells showed antigen-specific functionality in vitro and in vivo. Furthermore, FAP expression was verified in all MPM histotypes. Therefore, our data support performing a phase I clinical trial in which MPM patients are treated with adoptively transferred FAP-specific re-directed T cells.

Pegfilgrastim reduces the length of hospitalization and the time to engraftment in multiple myeloma patients treated with melphalan 200 and auto-SCT compared with filgrastim.

To reduce the duration of neutropenia after conditioning chemotherapy and autologous peripheral blood stem cell transplantation (APBSCT), granulocyte-colony stimulating factors (G-CSF) are commonly administered. We retrospectively evaluated the impact of pegfilgrastim compared to filgrastim on neutrophil engraftment, hospital stay, and supportive measures in patients with multiple myeloma after conditioning with Melphalan 200 (Mel200) followed by APBSCT. Ninety-two APBSCT after Mel200 treatment were performed in 72 patients between January 2006 and December 2009 at our institution. Patients received either single-dose pegfilgrastim (n = 46; 50%), or daily filgrastim (n = 46; 50%) after APBSCT (median duration of filgrastim use, 9 days; range, 3-14 days). Duration of neutropenia grade IV was shorter with pegfilgrastim compared with filgrastim (median, 5 days (range, 3-14 days) versus 6 days (range, 3-9 days), p = 0.0079). The length of hospitalization differed significantly (pegfilgrastim (median, 14.5 days; range, 11-47 days) versus filgrastim (median, 15.5 days; range, 12-64 days), p = 0.024). Pegfilgrastim-treated patients had less red blood cell transfusions (median, 0 transfusions (range, 0-10) versus 0.5 transfusions (range, 0-9), p = 0.00065). Pegfilgrastim was associated with reduced cost of the treatment procedure compared with filgrastim (p = 0.031). Pegfilgrastim appears to be at least equivalent to filgrastim without additional expenditure in myeloma patients treated with Mel200 and APBSCT.

NY-ESO-1 protein glycosylated by yeast induces enhanced immune responses.

Vaccine strategies that target dendritic cells to elicit potent cellular immunity are the subject of intense research. Here we report that the genetically engineered yeast Saccharomyces cerevisiae, expressing the full-length tumour-associated antigen NY-ESO-1, is a versatile host for protein production. Exposing dendritic cells (DCs) to soluble NY-ESO-1 protein linked to the yeast a-agglutinin 2 protein (Aga2p) protein resulted in protein uptake, processing and MHC class I cross-presentation of NY-ESO-1-derived peptides. The process of antigen uptake and cross-presentation was dependent on the glycosylation pattern of NY-ESO-1-Aga2p protein and the presence of accessible mannose receptors. In addition, NY-ESO-1-Aga2p protein uptake by dendritic cells resulted in recognition by HLA-DP4 NY-ESO-1-specific CD4(+) T cells, indicating MHC class II presentation. Finally, vaccination of mice with yeast-derived NY-ESO-1-Aga2p protein led to an enhanced humoral and cellular immune response, when compared to the bacterially expressed NY-ESO-1 protein. Together, these data demonstrate that yeast-derived full-length NY-ESO-1-Aga2p protein is processed and presented efficiently by MHC class I and II complexes and warrants clinical trials to determine the potential value of S. cerevisiae as a host for cancer vaccine development.

Equivalence of pegfilgrastim and filgrastim in lymphoma patients treated with BEAM followed by autologous stem cell transplantation.

OBJECTIVE: To evaluate the impact of pegfilgrastim on engraftment, hospital stay and resources in patients with Hodgkin's and non-Hodgkin's lymphoma after conditioning with high-dose BEAM followed by autologous peripheral blood stem cell transplantation (APBSCT) compared with filgrastim. METHODS: We reviewed patient charts and our prospective transplantation database for clinical data from the post-transplant period. An integrated cost analysis, including the use of blood products and length of hospital stay, was also performed. RESULTS: Fourteen (26%) patients with Hodgkin's lymphoma and 40 (74%) patients with non-Hodgkin's lymphoma were analyzed. Thirty-four (68%) patients received single-dose pegfilgrastim (6 mg), and 20 (32%) patients received daily filgrastim (5 µg/kg) after APBSCT. No differences were observed regarding duration of neutropenia grade 4 (pegfilgrastim median 7 days/filgrastim median 8 days; p = 0.13), thrombocytopenia grade 4 (7/9.5 days, respectively; p = 0.21), fever (4.5/2 days; p = 0.057), intravenous antibiotic treatment (11/10 days; p = 0.75) or length of hospital stay (16.5/16 days; p = 0.27) between the groups. The use of pegfilgrastim resulted in 12% higher treatment-related costs when compared to filgrastim, without reaching statistical significance (p = 0.38). CONCLUSION: Pegfilgrastim appears to be equivalent to filgrastim after high-dose BEAM followed by APBSCT in the treatment of lymphoma patients.

Concomitant statin use does not impair the clinical outcome of patients with diffuse large B cell lymphoma treated with rituximab-CHOP.

Preclinical data indicated a detrimental effect of statins on the anti-lymphoma activity of rituximab. We evaluated the impact of concomitant statin medication on the response and survival of patients with diffuse large B cell lymphoma (DLBCL) receiving rituximab-cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP) as first-line therapy. Medical histories of patients with DLBCL who were treated with R-CHOP as first-line therapy were assessed for concomitant statin use, response after completion of chemotherapy, event-free survival (EFS), and overall survival (OS). Furthermore, 2-[(18)F]fluor-2-deoxyglucose (FDG)-PET/CT results after completion of first-line therapy were compared between the groups. Overall, 145 patients with DLBCL treated with R-CHOP from January 2001 to December 2009 were analyzed. Twenty-one (15%) patients received statins throughout therapy. Five-year EFS was 67.3% in patients without statins compared with 79% in patients receiving statins during R-CHOP (HR, 0.47; 95% CI, 0.15-1.54, p = 0.2). Five-year OS was 81.4% for patients without statins compared with 93.3% for patients taking statins (HR, 0.58; 95% CI 0.07-4.55, p = 0.6). There were no statistically significant differences in the rates of complete remissions between the two groups (75% in the non-statin group versus 86% in the statin group, p = 0.45). A trend toward a lower rate of complete metabolic responses in FDG-PET/CT after chemotherapy was seen in patients without statin medication compared with the patients taking statins (84% versus 92%, p = 0.068). Concomitant statin use had no adverse impact on response to chemotherapy, EFS, and OS in patients treated with R-CHOP for DLBCL.

Expression and Mutation Patterns of PBRM1, BAP1 and SETD2 Mirror Specific Evolutionary Subtypes in Clear Cell Renal Cell Carcinoma.

Bi-allelic inactivation of the VHL gene on chromosome 3p is the characteristic feature in most clear cell renal cell carcinomas (ccRCC). Frequent gene alterations were also identified in SETD2, BAP1 and PBRM1, all of which are situated on chromosome 3p and encode histone/chromatin regulators. The relationship between gene mutation, loss of protein expression and the correlations with clinicopathological parameters is important for the understanding of renal cancer progression. We analyzed PBRM1 and BAP1 protein expression as well as the tri-methylation state of H3K36 as a surrogate marker for SETD2 activity in more than 700 RCC samples. In ccRCC loss of nuclear PBRM1 (68%), BAP1 (40%) and H3K36me3 (47%) expression was significantly correlated with each other, advanced tumor stage, poor tumor differentiation (P < .0001 each), and necrosis (P < .005) Targeted next generation sequencing of 83 ccRCC samples demonstrated a significant association of genetic mutations in PBRM1, BAP1, and SETD2 with absence of PBRM1, BAP1, and HEK36me3 protein expression (P < .05, each). By assigning the protein expression patterns to evolutionary subtypes, we revealed similar clinical phenotypes as suggested by TRACERx Renal. Given their important contribution to tumor suppression, we conclude that combined functional inactivation of PBRM1, BAP1, SETD2 and pVHL is critical for ccRCC progression.

Impact of Docetaxel on blood-brain barrier function and formation of breast cancer brain metastases.

BACKGROUND: Breast cancer (BC) is the most frequent malignant tumor in females and the 2nd most common cause of brain metastasis (BM), that are associated with a fatal prognosis. The increasing incidence from 10% up to 40% is due to more effective treatments of extracerebral sites with improved prognosis and increasing use of MRI in diagnostics. A frequently administered, potent chemotherapeutic group of drugs for BC treatment are taxanes usually used in the adjuvant and metastatic setting, which, however, have been suspected to be associated with a higher incidence of BM. The aim of our study was to experimentally analyze the impact of the taxane docetaxel (DTX) on brain metastasis formation, and to elucidate the underlying molecular mechanism. METHODS: A monocentric patient cohort was analyzed to determine the association of taxane treatment and BM formation. To identify the specific impact of DTX, a murine brain metastatic model upon intracardial injection of breast cancer cells was conducted. To approach the functional mechanism, dynamic contrast-enhanced MRI and electron microscopy of mice as well as in-vitro transendothelial electrical resistance (TEER) and tracer permeability assays using brain endothelial cells (EC) were carried out. PCR-based, immunohistochemical and immunoblotting analyses with additional RNA sequencing of murine and human ECs were performed to explore the molecular mechanisms by DTX treatment. RESULTS: Taxane treatment was associated with an increased rate of BM formation in the patient cohort and the murine metastatic model. Functional studies did not show unequivocal alterations of blood-brain barrier properties upon DTX treatment in-vivo, but in-vitro assays revealed a temporary DTX-related barrier disruption. We found disturbance of tubulin structure and upregulation of tight junction marker claudin-5 in ECs. Furthermore, upregulation of several members of the tubulin family and downregulation of tetraspanin-2 in both, murine and human ECs, was induced. CONCLUSION: In summary, a higher incidence of BM was associated with prior taxane treatment in both a patient cohort and a murine mouse model. We could identify tubulin family members and tetraspanin-2 as potential contributors for the destabilization of the blood-brain barrier. Further analyses are needed to decipher the exact role of those alterations on tumor metastatic processes in the brain.

MiR-99b-5p expression and response to tyrosine kinase inhibitor treatment in clear cell renal cell carcinoma patients.

A number of treatments targeting VEGF or mTOR pathways have been approved for metastatic clear cell Renal Cell Carcinoma (ccRCC), but the majority of patients show disease progression after first line therapy with a very low rate of complete or long-term responders. It has been shown that miRs may play a role in prediction of treatment response in various cancer types. The aim of our study was to identify a miR signature predictive for RCC patients' response to antiangiogenic tyrosine kinase inhibitor (TKI) treatment in the first line therapy. Sequencing of 40 paired normal/tumor formalin fixed and paraffin embedded ccRCC tissues revealed separate clustering via unsupervised dendrograms. With supervised analysis, the strongest differential expression was obtained with miR-99b-5p, which was significantly lower in patients with short progression free survival (<8 months) and TKI non-responders (progressive disease patients according to RECIST) (p<0.0001, each). Validation using RTqPCR and a second patient cohort compiled from three different hospitals (n=65) showed higher expression of miR-99b-5p in complete responders, but this trend did not reach statistical significance. It is concluded that low miR-99b-5p expression analyzed with sequencing methodology may correlate with tumor progression in TKI-treated ccRCC patients.

Oncotargets in different renal cancer subtypes.

Renal cell cancer is a heterogeneous group of cancers with different histologic subtypes. The majority of renal tumors in adults are clear cell renal cell carcinomas, which are characterized by von Hippel- Lindau (VHL) gene alterations. Recent advances in defining the genetic landscape of renal cancer has shown the genetic heterogeneity of clear cell renal cell carcinomas (ccRCC) and the presence of at least 3 additional ccRCC tumor suppressor genes on chromosome 3p. Due to inactivation of VHL, renal cancer cells produce the HIF-responsive growth factor VEGF. The PI3K--mTORC1 signaling axis also represents a target for therapy. The new systemic therapies, including tyrosine kinase inhibitors, monoclonal antibodies, and mTOR inhibitors, aim to suppress angiogenesis with vascular endothelial growth factor as a target. Various VEGF-inhibitors are approved for the treatment of ccRCC and we discuss recent advancements in the treatment of metastatic ccRCC. Other gene alterations have been identified in hereditary cancer syndromes, e.g. FLCN, TSC1, TSC2, TFE3, TFEB, MITF, FH, SDHB, SDHD, MET, and PTEN and we review their role in renal tumor carcinogenesis, prognosis, and targeted therapy. By reviewing the associations between morphologic features and molecular genetics of renal cancer we provide insight into the basis for targeted renal cancer therapy.

Identification of an HLA-A*02 restricted immunogenic peptide derived from the cancer testis antigen HOM-MEL-40/SSX2.

HOM-MEL-40/SSX2 is a SEREX-defined cancer testis antigen with frequent expression in various human neoplasms. To search for HLA-A*0201 restricted peptides that induce HOM-MEL-40/SSX2-specific CD8+ responses in breast cancer patients, we used the SYFPEITHI algorithm to identify three HOM-MEL-40/SSX2-derived nonamers with high binding affinity for HLA-A*0201, which has a prevalence of 40% in the Caucasian population. Of the three peptides, p41-49 and p103-111 but not p167-175 had been shown to be processed by the proteasome. Only stimulation with p103-111 induced HOM-MEL-40-specific CTLs in 5/7 patients with HOM-MEL-40/SSX2 positive breast cancers and in 6/11 healthy controls. HLA-A*0201 restriction of p103-111 was demonstrated by blocking with specific antibodies. The natural processing and presentation of p103-111 was demonstrated by the recognition of the HOM-MEL-40/SSX2 positive cell line SK-MEL-37 and of COS7/A2 cells transfected with HOM-MEL-40/SSX2 by p103-111 specific CD8+ cells. No correlation was found between CD8+ T-cell responses against p103-111 and anti-HOM-MEL-40/SSX2 antibody titers in the serum of patients, suggesting that CD8+ and B-cell responses against HOM-MEL-40/SSX2 are regulated independently. p103-111 holds promise as a broadly applicable peptide vaccine for patients with HOM-MEL-40/SSX2 positive neoplasms.

Recombinant antigen expression on yeast surface (RAYS) for the detection of serological immune responses in cancer patients.

The serological analysis of antigens by recombinant expression cloning (SEREX) has identified a multitude of new tumor antigens in many different tumor entities. These antigens can be grouped into different classes according to their specificities, with cancer/testis antigens appearing to be the most attractive candidates for vaccine development. The observation that CD8 and CD4 T-cell responses against cancer/testis antigens such as NY-ESO-1 correlate with the presence of specific antibodies demonstrates the importance of serological monitoring patients participating in vaccine trials. However, all serological assays available (Western blot, phage display and ELISA) are hampered by the fact that the protein cannot be analyzed in its natural conformation. We have thus developed a yeast display system where the antigen is expressed on the yeast surface (RAYS), allowing for a more natural folding of the protein. To validate this approach we displayed the A33 colorectal cancer antigen on the yeast cell surface and demonstrated specific binding by an A33 monoclonal antibody recognizing a conformation-dependent epitope on the A33 antigen. We then compared RAYS with the more commonly used ELISA and Western blot serological monitoring methods by analyzing 50 sera from cancer patients with known NY-ESO-1 antibody status and 10 sera from patients with unknown SSX2 antibody status in a blind fashion. RAYS appears at least equivalent to both ELISA and Western blotting for the monitoring of antibodies against NY-ESO-1 as regards specificity and sensitivity, while antibodies against SSX2 were detected more frequently by RAYS than by ELISA or phage display.

Antigen-specific in vitro expansion of functional redirected NY-ESO-1-specific human CD8+ T-cells in a cell-free system.

BACKGROUND: Tumors can be targeted by the adoptive transfer of chimeric antigen receptor (CAR) redirected T-cells. Antigen-specific expansion protocols are needed to generate large quantities of redirected T-cells. We aimed to establish a protocol to expand functional active NY-ESO-1-specific redirected human CD8(+) T-cells. MATERIALS AND METHODS: The anti-idiotypic Fab antibody A4 with specificity for HLA-A 0201/NY-ESO-1157-165 was tested by competition assays using a HLA-A 0201/NY-ESO-1157-165 tetramer. HLA-A 0201/NY-ESO-1157-165 redirected T-cells were generated, expanded and tested for CAR expression, cytokine release, in vitro cytolysis and protection against xenografted HLA-A 0201/NY-ESO-1157-165-positive multiple myeloma cells. RESULTS: A4 demonstrated antigen-specific binding to HLA-A 0201/NY-ESO-1157-165 redirected T-cells. Expansion with A4 resulted in 98% of HLA-A 0201/NY-ESO-1157-165 redirected T-cells. A4 induced strong proliferation, resulting in a 300-fold increase of redirected T-cells. After expansion protocols, redirected T-cells secreted Interleukin-2, (IL-2), interferon gamma (IFNγ) and tumor necrosis factor alpha (TNFα) and lysed target cells in vitro and were protective in vivo. CONCLUSION: A4 expanded HLA-A 0201/NY-ESO-1157-165 redirected T-cells with preservation of antigen-specific function.

RP1 is a phosphorylation target of CK2 and is involved in cell adhesion.

RP1 (synonym: MAPRE2, EB2) is a member of the microtubule binding EB1 protein family, which interacts with APC, a key regulatory molecule in the Wnt signalling pathway. While the other EB1 proteins are well characterized the cellular function and regulation of RP1 remain speculative to date. However, recently RP1 has been implicated in pancreatic cancerogenesis. CK2 is a pleiotropic kinase involved in adhesion, proliferation and anti-apoptosis. Overexpression of protein kinase CK2 is a hallmark of many cancers and supports the malignant phenotype of tumor cells. In this study we investigate the interaction of protein kinase CK2 with RP1 and demonstrate that CK2 phosphorylates RP1 at Ser(236) in vitro. Stable RP1 expression in cell lines leads to a significant cleavage and down-regulation of N-cadherin and impaired adhesion. Cells expressing a Phospho-mimicking point mutant RP1-ASP(236) show a marked decrease of adhesion to endothelial cells under shear stress. Inversely, we found that the cells under shear stress downregulate endogenous RP1, most likely to improve cellular adhesion. Accordingly, when RP1 expression is suppressed by shRNA, cells lacking RP1 display significantly increased cell adherence to surfaces. In summary, RP1 phosphorylation at Ser(236) by CK2 seems to play a significant role in cell adhesion and might initiate new insights in the CK2 and EB1 family protein association.