Proteomic Profiling of Advanced Melanoma Patients to Predict Therapeutic Response to Anti-PD-1 Therapy.

PURPOSE: Despite high clinical need, there are no biomarkers that accurately predict the response of patients with metastatic melanoma to anti-PD-1 therapy. EXPERIMENTAL DESIGN: In this multicenter study, we applied protein depletion and enrichment methods prior to various proteomic techniques to analyze a serum discovery cohort (n = 56) and three independent serum validation cohorts (n = 80, n = 12, n = 17). Further validation analyses by literature and survival analysis followed. RESULTS: We identified several significantly regulated proteins as well as biological processes such as neutrophil degranulation, cell-substrate adhesion, and extracellular matrix organization. Analysis of the three independent serum validation cohorts confirmed the significant differences between responders (R) and nonresponders (NR) observed in the initial discovery cohort. In addition, literature-based validation highlighted 30 markers overlapping with previously published signatures. Survival analysis using the TCGA database showed that overexpression of 17 of the markers we identified correlated with lower overall survival in patients with melanoma. CONCLUSIONS: Ultimately, this multilayered serum analysis led to a potential marker signature with 10 key markers significantly altered in at least two independent serum cohorts: CRP, LYVE1, SAA2, C1RL, CFHR3, LBP, LDHB, S100A8, S100A9, and SAA1, which will serve as the basis for further investigation. In addition to patient serum, we analyzed primary melanoma tumor cells from NR and found a potential marker signature with four key markers: LAMC1, PXDN, SERPINE1, and VCAN.

New therapeutic developments for basal cell carcinoma.

In 2013, systemic therapy was introduced into the treatment of locally advanced (laBCC) and metastatic basal cell carcinoma (mBCC). Meanwhile, immunotherapy has been approved in this indication as well. Additional immunotherapies and other classes of drugs including combination regimens are currently being investigated in clinical trials. These agents might considerably expand the therapeutic armamentarium for laBCC and mBCC in the future.

Proteomic identification of a marker signature for MAPKi resistance in melanoma.

MAPK inhibitors (MAPKi) show outstanding clinical response rates in melanoma patients harbouring BRAF mutations, but resistance is common. The ability of melanoma cells to switch from melanocytic to mesenchymal phenotypes appears to be associated with therapeutic resistance. High-throughput, subcellular proteome analyses and RNAseq on two panels of primary melanoma cells that were either sensitive or resistant to MAPKi revealed that only 15 proteins were sufficient to distinguish between these phenotypes. The two proteins with the highest discriminatory power were PTRF and IGFBP7, which were both highly upregulated in the mesenchymal-resistant cells. Proteomic analysis of CRISPR/Cas-derived PTRF knockouts revealed targets involved in lysosomal activation, endocytosis, pH regulation, EMT, TGFß signalling and cell migration and adhesion, as well as a significantly reduced invasive index and ability to form spheres in 3D culture. Overexpression of PTRF led to MAPKi resistance, increased cell adhesion and sphere formation. In addition, immunohistochemistry of patient samples showed that PTRF expression levels were a significant biomarker of poor progression-free survival, and IGFBP7 levels in patient sera were shown to be higher after relapse.

Granuloma Annulare and Radial Pulse Therapy: Preliminary Findings.

In this case report, the authors describe a first-time trial of a variation of extracorporeal shockwave therapy in a patient with disseminated granuloma annulare. Radial pulse therapy was administered in an outpatient clinic of a university hospital to a 72-year-old woman with a 14-year history of disseminated granuloma annulare. The authors describe changes in clinical appearance and results of histological evaluation, reporting observable positive changes in all four treated plaques. The authors conclude that radial pulse therapy was well-tolerated and seemed to influence the course of disseminated granuloma annulare plaques positively.

Assessment of quality of life using Skindex-16 in patients with advanced basal cell carcinoma treated with vismodegib in the STEVIE study.

Health-related quality of life (HRQoL) data are limited in patients with advanced basal cell carcinoma. To report HRQoL outcomes based on STEVIE (NCT01367665), a phase 2 study of vismodegib safety in patients with metastatic BCC or locally advanced BCC that is unsuitable for surgery or radiotherapy. Skindex-16 and MD Anderson Symptom Inventory (MDASI) questionnaires were completed at baseline and at three subsequent visits. Clinically meaningful improvement was defined as a ≥10-point decrease from baseline (Skindex-16) or improvement of at least 3 points from baseline (MDASI). HRQoL-evaluable patients with locally advanced BCC (n = 730) had ≥10-point improvements in Skindex-16 emotion domain scores at all time points. Changes in symptom and function scores in these patients or in any domain scores at any time point in patients with metastatic BCC (n = 10) were not clinically meaningful. Of 10 patients with symptomatic metastatic BCC at baseline, six had ≥3-point improvements in MDASI symptom severity. Skindex-16 and MDASI showed improvement in HRQoL in vismodegib-treated patients with locally advanced or metastatic BCC or BCC.

Two intermittent vismodegib dosing regimens in patients with multiple basal-cell carcinomas (MIKIE): a randomised, regimen-controlled, double-blind, phase 2 trial.

BACKGROUND: Vismodegib, a first-in-class Hedgehog-pathway inhibitor, is approved for use in adults with advanced basal-cell carcinoma. Patients with multiple basal-cell carcinomas, including those with basal-cell nevus (Gorlin) syndrome, need extended treatment. We assessed the safety and activity of two long-term intermittent vismodegib dosing regimens in patients with multiple basal-cell carcinomas. METHODS: In this randomised, regimen-controlled, double-blind, phase 2 trial, we enrolled adult patients with multiple basal-cell carcinomas, including those with basal-cell nevus syndrome, who had one or more histopathologically confirmed and at least six clinically evident basal-cell carcinomas. From a centralised randomisation schedule accessed via an interactive voice or web-based response system, patients were randomly assigned (1:1) to treatment group A (150 mg oral vismodegib per day for 12 weeks, then three rounds of 8 weeks of placebo daily followed by 12 weeks of 150 mg vismodegib daily) or treatment group B (150 mg oral vismodegib per day for 24 weeks, then three rounds of 8 weeks of placebo daily followed by 8 weeks of 150 mg vismodegib daily). Treatment assignment was stratified by diagnosis of basal-cell nevus syndrome, geographical region, and immunosuppression status. The primary endpoint was percentage reduction from baseline in the number of clinically evident basal-cell carcinomas at week 73. The primary analysis was by intention to treat. The safety population included all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT01815840, and the study is ongoing. FINDINGS: Between April 30, 2013, and April 9, 2014, 229 patients were randomly assigned treatment, 116 in treatment group A and 113 in treatment group B. The mean number of basal-cell carcinoma lesions at week 73 was reduced from baseline by 62·7% (95% CI 53·0-72·3) in treatment group A and 54·0% (43·6-64·4) in treatment group B. 216 (95%) of 227 patients included in the safety analysis had at least one treatment-emergent adverse event deemed to be related to study treatment (107 [94%] of 114 in treatment group A and 109 [97%] of 113 in treatment group B). The most common grade 3 or worse treatment-related adverse events were muscle spasms (four [4%] patients in treatment group A vs 12 [11%] in treatment group B), increased blood creatine phosphokinase (one [1%] vs four [4%]), and hypophosphataemia (zero vs three [3%]). Serious treatment-emergent events were noted in 22 (19%) patients in treatment group A and 19 (17%) patients in treatment group B. Four (2%) patients died from adverse events; one (pulmonary embolism in treatment group A) was possibly related to treatment. INTERPRETATION: Both intermittent dosing schedules of vismodegib seemed to show good activity in long-term regimens in patients with multiple basal-cell carcinomas. Further study is warranted. FUNDING: F Hoffmann-La Roche.

ESMO / ASCO Recommendations for a Global Curriculum in Medical Oncology Edition 2016.

The European Society for Medical Oncology (ESMO) and the American Society of Clinical Oncology (ASCO) are publishing a new edition of the ESMO/ASCO Global Curriculum (GC) thanks to contribution of 64 ESMO-appointed and 32 ASCO-appointed authors. First published in 2004 and updated in 2010, the GC edition 2016 answers to the need for updated recommendations for the training of physicians in medical oncology by defining the standard to be fulfilled to qualify as medical oncologists. At times of internationalisation of healthcare and increased mobility of patients and physicians, the GC aims to provide state-of-the-art cancer care to all patients wherever they live. Recent progress in the field of cancer research has indeed resulted in diagnostic and therapeutic innovations such as targeted therapies as a standard therapeutic approach or personalised cancer medicine apart from the revival of immunotherapy, requiring specialised training for medical oncology trainees. Thus, several new chapters on technical contents such as molecular pathology, translational research or molecular imaging and on conceptual attitudes towards human principles like genetic counselling or survivorship have been integrated in the GC. The GC edition 2016 consists of 12 sections with 17 subsections, 44 chapters and 35 subchapters, respectively. Besides renewal in its contents, the GC underwent a principal formal change taking into consideration modern didactic principles. It is presented in a template-based format that subcategorises the detailed outcome requirements into learning objectives, awareness, knowledge and skills. Consecutive steps will be those of harmonising and implementing teaching and assessment strategies.

Characterization and Management of Hedgehog Pathway Inhibitor-Related Adverse Events in Patients With Advanced Basal Cell Carcinoma.

Abnormal activation of hedgehog pathway signaling is a key driver in the pathogenesis of basal cell carcinoma (BCC). Vismodegib, a first-in-class small-molecule inhibitor of hedgehog pathway signaling, is approved by regulatory authorities for the treatment of adults who have metastatic BCC or locally advanced BCC that has recurred after surgery, or who are not candidates for surgery and who are not candidates for radiation. A second inhibitor, sonidegib, was also recently approved for the same patient group with locally advanced BCC. Adverse events (AEs) commonly observed in hedgehog pathway inhibitor (HPI)-treated patients include muscle spasms, ageusia/dysgeusia, alopecia, weight loss, and asthenia (fatigue). These AEs are thought to be mechanistically related to inhibition of the hedgehog pathway in normal tissue. Although the severity of the majority of AEs associated with HPIs is grade 1-2, the long-term nature of these AEs can lead to decreased quality of life, treatment interruption, and in some cases discontinuation, all of which might affect clinical outcome. The incidence, clinical presentation, putative mechanisms, and management strategies for AEs related to HPIs in advanced BCC are described. These observations represent the first step toward the development of mechanism-based preventive and management strategies. Knowledge of these AEs will allow health care professionals to provide appropriate counseling and supportive care interventions, all of which will contribute to improved quality of life and optimal benefit from therapy. IMPLICATIONS FOR PRACTICE: The hedgehog pathway inhibitors (HPIs) vismodegib and sonidegib represent a therapeutic breakthrough for patients with advanced basal cell carcinoma. However, the nature of the low-grade adverse events (AEs) commonly observed in HPI-treated patients, including muscle spasms, ageusia/dysgeusia, alopecia, weight loss, and fatigue, can impact clinical outcomes as a result of decreased quality of life and treatment discontinuation. The incidence, clinical presentation, putative mechanisms, and management strategies for AEs related to administration of HPIs are described, with the goal of enabling health care professionals to provide appropriate counseling and supportive care interventions to their patients.

Merkel cell carcinoma: Overall survival after open biopsy versus wide local excision.

BACKGROUND: Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin with a dismal prognosis. METHODS: We conducted a retrospective medical chart review of patients with MCC who were initially diagnosed with an open biopsy (n = 30) or wide local excision (n = 24). RESULTS: Stages I, II, and III disease was found in 38%, 20%, and 16%, respectively. The 2-year and 5-year overall and disease-specific survival rates were 64.8% and 38.8% versus 45.2% and 26.4%, respectively. Cox regression multivariate model, including tissue sampling technique, re-resection, therapy modalities, pathological staging, and T and N classifications, showed that patients diagnosed initially with an open biopsy have significant worse overall (p = .014) and disease-free (p = .005) survival rates compared with patients who had a wide local excision. CONCLUSION: This study showed an improved overall survival in patients with MCC after wide local excision compared to open biopsy of the primary site at first diagnosis. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1014-E1018, 2016.

Vismodegib in patients with advanced basal cell carcinoma (STEVIE): a pre-planned interim analysis of an international, open-label trial.

BACKGROUND: The Hedgehog pathway inhibitor vismodegib has shown clinical benefit in patients with advanced basal cell carcinoma and is approved for treatment of patients with advanced basal cell carcinoma for whom surgery is inappropriate. STEVIE was designed to assess the safety of vismodegib in a situation similar to routine practice, with a long follow-up. METHODS: In this multicentre, open-label trial, adult patients with histologically confirmed locally advanced basal cell carcinoma or metastatic basal cell carcinoma were recruited from regional referral centres or specialist clinics. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, and adequate organ function. Patients with locally advanced basal cell carcinoma had to have been deemed ineligible for surgery. All patients received 150 mg oral vismodegib capsules once a day on a continuous basis in 28-day cycles. The primary objective was safety (incidence of adverse events until disease progression or unacceptable toxic effects), with assessments on day 1 of each treatment cycle (28 days) by principal investigator and coinvestigators at the site. Efficacy variables were assessed as secondary endpoints. The safety evaluable population included all patients who received at least one dose of study drug. Patients with histologically confirmed basal cell carcinoma who received at least one dose of study drug were included in the efficacy analysis. An interim analysis was pre-planned after 500 patients achieved 1 year of follow-up. This trial is registered with ClinicalTrials.gov, number NCT01367665. The study is still ongoing. FINDINGS: Between June 30, 2011, and Nov 6, 2014, we enrolled 1227 patients. At clinical cutoff (Nov 6, 2013), 499 patients (468 with locally advanced basal cell carcinoma and 31 with metastatic basal cell carcinoma) had received study drug and had the potential to be followed up for 12 months or longer. Treatment was discontinued in 400 (80%) patients; 180 (36%) had adverse events, 70 (14%) had progressive disease, and 51 (10%) requested to stop treatment. Median duration of vismodegib exposure was 36·4 weeks (IQR 17·7-62·0). Adverse events happened in 491 (98%) patients; the most common were muscle spasms (317 [64%]), alopecia (307 [62%]), dysgeusia (269 [54%]), weight loss (162 [33%]), asthenia (141 [28%]), decreased appetite (126 [25%]), ageusia (112 [22%]), diarrhoea (83 [17%]), nausea (80 [16%]), and fatigue (80 [16%]). Most adverse events were grade 1 or 2. We recorded serious adverse events in 108 (22%) of 499 patients. Of the 31 patients who died, 21 were the result of adverse events. As assessed by investigators, 302 (66·7%, 62·1-71·0) of 453 patients with locally advanced basal cell carcinoma had an overall response (153 complete responses and 149 partial responses); 11 (37·9%; 20·7-57·7) of 29 patients with metastatic basal cell carcinoma had an overall response (two complete responses, nine partial responses). INTERPRETATION: This study assessed the use of vismodegib in a setting representative of routine clinical practice for patients with advanced basal cell carcinoma. Our results show that treatment with vismodegib adds a novel therapeutic modality from which patients with advanced basal cell carcinoma can benefit substantially. FUNDING: F Hoffmann-La Roche.

Vemurafenib resistance signature by proteome analysis offers new strategies and rational therapeutic concepts.

The FDA-approved BRAF inhibitor vemurafenib achieves outstanding clinical response rates in patients with melanoma, but early resistance is common. Understanding the pathologic mechanisms of drug resistance and identification of effective therapeutic alternatives are key scientific challenges in the melanoma setting. Using proteomic techniques, including shotgun analysis and 2D-gel electrophoresis, we identified a comprehensive signature of the vemurafenib-resistant M24met in comparison with the vemurafenib-sensitive A375 melanoma cell line. The resistant cells were characterized by loss of differentiation, induction of transformation, enhanced expression of the lysosomal compartment, increased potential for metastasis, migration, adherence and Ca2(+) ion binding, enhanced expression of the MAPK pathway and extracellular matrix proteins, and epithelial-mesenchymal transformation. The main features were verified by shotgun analysis with QEXACTIVE orbitrap MS, electron microscopy, lysosomal staining, Western blotting, and adherence assay in a VM-1 melanoma cell line with acquired vemurafenib resistance. On the basis of the resistance profile, we were able to successfully predict that a novel resveratrol-derived COX-2 inhibitor, M8, would be active against the vemurafenib-resistant but not the vemurafenib-sensitive melanoma cells. Using high-throughput methods for cell line and drug characterization may thus offer a new way to identify key features of vemurafenib resistance, facilitating the design of effective rational therapeutic alternatives.

Proteome profiling of keratinocytes transforming to malignancy.

To shed light on the multistep process of squamous cell carcinoma development and the underlying pathologic mechanisms, we performed comparative proteome analysis of keratinocytes, keratinocytes stimulated with Il-1beta, and A431 epidermoid carcinoma cells. Fractionation of the cells into supernatant, nucleus, and cytoplasm was followed by protein separation, proteolytic digest, and nano-LC separation, and fragmentation using an ion trap mass spectrometer. Specific bioinformatics tools were used to generate a list of keratinocyte-specific proteins. Ninety percent of these proteins were found to be upregulated in keratinocytes versus the A431 cells. Classification of the identified proteins by biologic function and gene set enrichment analysis revealed that keratinocytes produced more proteins involved in cell differentiation, cell adhesion, cell junction, calcium ion, calmodulin binding, cytoskeleton organization, and cytokinesis, whereas A431 produced more proteins involved in cell cycle checkpoint, cell cycle process, RNA processing and transport, DNA damage and repair, RNA and DNA binding, and chromatin remodeling. The protein signatures of A431 and normal keratinocytes treated with IL-1beta showed marked similarity, confirming that inflammation is an important step in malignant transformation in nonmelanoma skin cancer. Thus, proteome profiling and bioinformatic processing may support the understanding of the underlying mechanisms, with the potential to facilitate development of early biomarkers and patient-tailored therapy.

Management of Merkel cell carcinoma of unknown primary origin: the Vienna Medical School experience.

Merkel cell carcinoma is a rare, but highly aggressive skin tumor. We describe our single-institution experience with the diagnosis and treatment of Merkel cell carcinoma of unknown primary (MCCUP). We conducted a retrospective medical chart review of patients treated with MCCUP at the Vienna General Hospital between 2002 and 2011. Clinicopathologic variables and outcomes were analyzed. Of the entire cohort of 57 patients, 8 patients (14%) were diagnosed with MCCUP. Three patients presented with parotid gland involvement, four patients with positive inguinal lymph nodes and one with axillar lymph nodes. CK20 staining was positive in all tumor specimens, whereas MCPyV protein was positive in four out of six patients. The primary surgical modality in five cases was wide local excision. In one patient excisional biopsy was followed by re-resection. In one case only excisional biopsy was performed due to metastatic disease at first diagnosis. Two patients underwent concomitant parotidectomy and neck dissection, and four patients received adjuvant radiation therapy. Median recurrence-free survival was 20 months. Four patients died, three of disease and one of other cause. Recurrent disease was observed in two patients and treated with radiotherapy and chemotherapy. The 1- and 3-year overall survival rates were 87.5 and 37.5%, respectively. The 1- and 3-year disease-specific survival rates were 87.5 and 62.5%, respectively. Our study shows a poor outcome in patients with MCCUP, particularly in patients with node involvement of the trunk. We therefore suggest an aggressive and multimodal treatment approach for patients with MCCUP.

Prognostic significance of lymph node ratio in patients with Merkel cell carcinoma.

Merkel cell carcinoma is a rare and aggressive metastasizing tumor of the skin. Lymph node metastasis is a significant clinical prognostic factor for overall and disease-free survival in patients with Merkel cell carcinoma. A retrospective medical chart review of 12 Merkel cell carcinoma patients was performed. All patients received treatment at the Medical University of Vienna and underwent lymph node dissection between 1994 and 2013. The lymph node ratio was determined by dividing the total number of positive lymph nodes by the entire number of dissected lymph nodes. A positive lymph node ratio was defined as a number >0 and the negative lymph node ratio was defined by zero. The median follow-up was 44 months (range 4-92). A positive lymph node ratio (range 1.00-0.04) was found in 7 (58%) out of 12 patients of whom 5 (71%) died of disease. A negative lymph node ratio was found in 5 (42%) out of 12 patients of whom 2 (40%) patients died of disease. The disease-specific death rate was higher in patients diagnosed with a positive lymph node ratio compared to patients diagnosed with a negative lymph node ratio. Based on these preliminary findings, there might be a prognostic impact of lymph node ratio in patients suffering from Merkel cell carcinoma.

Emerging drugs and combination strategies for basal cell carcinoma.

INTRODUCTION: Basal cell carcinoma (BCC) is a malignancy that is driven by an activated Hedgehog (Hh) pathway. Smoothened inhibitors are a new promising treatment option for patients with locally advanced or metastatic BCC or basal cell nevus syndrome. But long-term data are still limited, the optimal treatment duration is not yet defined and there are already documented cases with acquired resistance. AREAS COVERED: Treatment modalities with Hh inhibitors, side effects and potential pharmacological combination options are discussed. The current literature, including PubMed, Cochrane database and registered trials on ClinicalTrials.gov, was searched. EXPERT OPINION: BCCs typically regress during therapy with Hh inhibitors. Muscle toxicity, dysgeusia and hair loss can be considered as on target adverse reactions. Muscle toxicity is the dose-limiting toxicity of sonidegib. It was not seen with vismodegib because of its high binding to plasma protein α-1-acid glycoprotein. Sonidegib is different and shows a clear dose-toxicity relationship, which allows to address the question of whether there is a dose dependency of regression rate, cure rate and progression-free survival. In addition, basic research has offered strategies to enhance efficacy by the combination with other molecules, such as EGFR inhibitors, MEK inhibitors or immunotherapy.

Thrombospondin-2 overexpression in the skin of transgenic mice reduces the susceptibility to chemically induced multistep skin carcinogenesis.

BACKGROUND: We have previously reported stromal upregulation of the endogenous angiogenesis inhibitor thrombospondin-2 (TSP-2) during multistep carcinogenesis, and we found accelerated and enhanced skin angiogenesis and carcinogenesis in TSP-2 deficient mice. GOALS: To investigate whether enhanced levels of TSP-2 might protect from skin cancer development. METHODS: We established transgenic mice with targeted overexpression of TSP-2 in the skin and subjected hemizygous TSP-2 transgenic mice and their wild-type littermates to a chemical skin carcinogenesis regimen. RESULTS: TSP-2 transgenic mice showed a significantly delayed onset of tumor formation compared to wild-type mice, whereas the ratio of malignant conversion to squamous cell carcinomas was comparable in both genotypes. Computer-assisted morphometric analysis of blood vessels revealed pronounced tumor angiogenesis already in the early stages of carcinogenesis in wild type mice. TSP-2 overexpression significantly reduced tumor blood vessel density in transgenic mice but had no overt effect on LYVE-1 positive lymphatic vessels. The percentage of desmin surrounded, mature tumor-associated blood vessels and the degree of epithelial differentiation remained unaffected. The antiangiogenic effect of transgenic TSP-2 was accompanied by a significantly increased number of apoptotic tumor cells in transgenic mice. CONCLUSION: Our results demonstrate that enhanced levels of TSP-2 in the skin result in reduced susceptibility to chemically-induced skin carcinogenesis and identify TSP-2 as a new target for the prevention of skin cancer.

Smoothened inhibitors in the treatment of advanced basal cell carcinomas.

PURPOSE OF REVIEW: The Hedgehog pathway has been identified as a key element in the development of many forms of cancer. Smoothened (Smo) inhibitors are known to beneficially interfere with the Hedgehog pathway and are currently under investigation as anticancer drugs for many tumor entities. Reviewed here are the most recent developments in clinical research on Smo inhibitors for the treatment of advanced basal cell carcinoma (BCC). RECENT FINDINGS: When reviewing the literature of the past 12 months, it is striking to see the rapid evolution of the field. Compounds that have been presented as powerful new drug candidates 12 months ago have now been discontinued, whereas new ones have emerged. Reports on 13 drug candidates have been identified: one marketed, vismodegib, eight currently under development (phase I-II) and four for which clinical investigation for BCC is currently not being pursued. SUMMARY: Smo inhibitors are a promising drug class for the treatment of BCC. To date, most candidates are in early stage development and are expected to enter the market in approximately 5-8 years, if successful.

Functional classification of cellular proteome profiles support the identification of drug resistance signatures in melanoma cells.

Drug resistance is a major obstacle in melanoma treatment. Recognition of specific resistance patterns, the understanding of the patho-physiology of drug resistance, and identification of remaining options for individual melanoma treatment would greatly improve therapeutic success. We performed mass spectrometry-based proteome profiling of A375 melanoma cells and HeLa cells characterized as sensitive to cisplatin in comparison to cisplatin resistant M24met and TMFI melanoma cells. Cells were fractionated into cytoplasm, nuclei and secretome and the proteome profiles classified according to Gene Ontology. The cisplatin resistant cells displayed increased expression of lysosomal as well as Ca²âº ion binding and cell adherence proteins. These findings were confirmed using Lysotracker Red staining and cell adhesion assays with a panel of extracellular matrix proteins. To discriminate specific survival proteins, we selected constitutively expressed proteins of resistant M24met cells which were found expressed upon challenging the sensitive A375 cells. Using the CPL/MUW proteome database, the selected lysosomal, cell adherence and survival proteins apparently specifying resistant cells were narrowed down to 47 proteins representing a potential resistance signature. These were tested against our proteomics database comprising more than 200 different cell types/cell states for its predictive power. We provide evidence that this signature enables the automated assignment of resistance features as readout from proteome profiles of any human cell type. Proteome profiling and bioinformatic processing may thus support the understanding of drug resistance mechanism, eventually guiding patient tailored therapy.

Merkel cell carcinoma: chemotherapy and emerging new therapeutic options.

Merkel cell carcinoma (MCC) is a rare neuroendocrine skin tumor that typically occurs in elderly, immunosuppressed patients. Infection with Merkel cell virus (MCV) and immunosuppression play an important role in the development of MCC. Different staging systems make it difficult to compare the existing clinical data. Furthermore, there predominantly exist single case reports and case series, but no randomized controlled trials. However, it is necessary to develop further therapy options because MCC tends to grow rapidly and metastasizes early. In the metastatic disease, therapeutic attempts were made with various chemotherapeutic combination regimens. Because of the high toxicity of these combinations, especially those established in SCLC, and regarding the unsatisfying results, the challenge is to balance the pros and cons of chemotherapy individually and carefully. Up to now, emerging new therapy options as molecular-targeted agents, for example, pazopanib, imatinib, or somatostatin analogues as well as immunologicals, for example, imiquimod and interferons, also showed less success concerning the disease-free response rates. According to the literature, neither chemotherapy nor molecular-targeted agents or immunotherapeutic strategies have shown promising effects in the therapy of the metastatic disease of MCC so far. There is a great demand for randomized controlled studies and a need for an MCC registry and multicenter clinical trials due to the tumors curiosity.