Proteomic profiling of triple-negative breast carcinomas in combination with a three-tier orthogonal technology approach identifies Mage-A4 as potential therapeutic target in estrogen receptor negative breast cancer.

Breast cancer is a very heterogeneous disease, encompassing several intrinsic subtypes with various morphological and molecular features, natural history and response to therapy. Currently, molecular targeted therapies are available for estrogen receptor (ER)(-) and human epidermal growth factor receptor 2 (Her2)-positive breast tumors. However, a significant proportion of primary breast cancers are negative for ER, progesterone receptor (PgR), and Her2, comprising the triple negative breast cancer (TNBC) group. Women with TNBC have a poor prognosis because of the aggressive nature of these tumors and current lack of suitable targeted therapies. As a consequence, the identification of novel relevant protein targets for this group of patients is of great importance. Using a systematic two dimensional (2D) gel-based proteomic profiling strategy, applied to the analysis of fresh TNBC tissue biopsies, in combination with a three-tier orthogonal technology (two dimensional PAGE/silver staining coupled with MS, two dimensional Western blotting, and immunohistochemistry) approach, we aimed to identify targetable protein markers that were present in a significant fraction of samples and that could define therapy-amenable sub-groups of TNBCs. We present here our results, including a large cumulative database of proteins based on the analysis of 78 TNBCs, and the identification and validation of one specific protein, Mage-A4, which was expressed in a significant fraction of TNBC and Her2-positive/ER negative lesions. The high level expression of Mage-A4 in the tumors studied allowed the detection of the protein in the tumor interstitial fluids as well as in sera. The existence of immunotherapeutics approaches specifically targeting this protein, or Mage-A protein family members, and the fact that we were able to detect its presence in serum suggest novel management options for TNBC and human epidermal growth factor receptor 2 positive/estrogen receptor negative patients bearing Mage-A4 positive tumors.

Proteomics in translational cancer research: toward an integrated approach.

Proteomics provides powerful tools for the study of clinically relevant samples in the context of translational cancer research. Here we briefly review applications of gel-based proteomics for the study of bladder and lung cancer using fresh tissue biopsies. In general, these studies have emphasized the potential of the technology for biomarker discovery, as well as for addressing the issue of cancer heterogeneity.

Bladder cancer-associated protein, a potential prognostic biomarker in human bladder cancer.

It is becoming increasingly clear that no single marker will have the sensitivity and specificity necessary to be used on its own for diagnosis/prognosis of tumors. Interpatient and intratumor heterogeneity provides overwhelming odds against the existence of such an ideal marker. With this in mind, our laboratory has been applying a long term systematic approach to identify multiple biomarkers that can be used for clinical purposes. As a result of these studies, we have identified and reported several candidate biomarker proteins that are deregulated in bladder cancer. Following the conceptual biomarker development phases proposed by the Early Detection Research Network, we have taken some of the most promising candidate proteins into postdiscovery validation studies, and here we report on the characterization of one such biomarker, the bladder cancer-associated protein (BLCAP), formerly termed Bc10. To characterize BLCAP protein expression and cellular localization patterns in benign bladder urothelium and urothelial carcinomas (UCs), we used two independent sets of samples from different patient cohorts: a reference set consisting of 120 bladder specimens (formalin-fixed as well as frozen biopsies) and a validation set consisting of 2,108 retrospectively collected UCs with long term clinical follow-up. We could categorize the UCs examined into four groups based on levels of expression and subcellular localization of BLCAP protein and showed that loss of BLCAP expression is associated with tumor progression. The results indicated that increased expression of this protein confers an adverse patient outcome, suggesting that categorization of staining patterns for this protein may have prognostic value. Finally, we applied a combinatorial two-marker discriminator using BLCAP and adipocyte-type fatty acid-binding protein, another UC biomarker previously reported by us, and found that the combination of the two markers correlated more closely with grade and/or stage of disease than the individual markers. The implications of these results in biomarker discovery are discussed.

The Porto European Cancer Research Summit 2021.

Key stakeholders from the cancer research continuum met in May 2021 at the European Cancer Research Summit in Porto to discuss priorities and specific action points required for the successful implementation of the European Cancer Mission and Europe's Beating Cancer Plan (EBCP). Speakers presented a unified view about the need to establish high-quality, networked infrastructures to decrease cancer incidence, increase the cure rate, improve patient's survival and quality of life, and deal with research and care inequalities across the European Union (EU). These infrastructures, featuring Comprehensive Cancer Centres (CCCs) as key components, will integrate care, prevention and research across the entire cancer continuum to support the development of personalized/precision cancer medicine in Europe. The three pillars of the recommended European infrastructures - namely translational research, clinical/prevention trials and outcomes research - were pondered at length. Speakers addressing the future needs of translational research focused on the prospects of multiomics assisted preclinical research, progress in Molecular and Digital Pathology, immunotherapy, liquid biopsy and science data. The clinical/prevention trial session presented the requirements for next-generation, multicentric trials entailing unified strategies for patient stratification, imaging, and biospecimen acquisition and storage. The third session highlighted the need for establishing outcomes research infrastructures to cover primary prevention, early detection, clinical effectiveness of innovations, health-related quality-of-life assessment, survivorship research and health economics. An important outcome of the Summit was the presentation of the Porto Declaration, which called for a collective and committed action throughout Europe to develop the cancer research infrastructures indispensable for fostering innovation and decreasing inequalities within and between member states. Moreover, the Summit guidelines will assist decision making in the context of a unique EU-wide cancer initiative that, if expertly implemented, will decrease the cancer death toll and improve the quality of life of those confronted with cancer, and this is carried out at an affordable cost.

A combined proteome and ultrastructural localization analysis of 14-3-3 proteins in transformed human amnion (AMA) cells: definition of a framework to study isoform-specific differences.

The 14-3-3 proteins constitute a family of highly conserved and broadly expressed multifunctional polypeptides that are involved in a variety of important cellular processes that include cell cycle progression, growth, differentiation, and apoptosis. Although the exact cellular function(s) of 14-3-3 proteins is not fully elucidated, as a rule these proteins act by binding to protein ligands, thus regulating their activity; so far more than 300 cellular proteins have been reported to interact with 14-3-3 proteins. Binding to cognate interacting partners is isoform-specific, but redundancy also exists as several binding peptides can be recognized by all isoforms, and some functions can be carried out by any isoform indistinctly. Moreover by interacting with different ligands in a spatially and temporally regulated fashion the same isoform can play multiple possibly even opposing roles where the resultant cellular outcome will be determined by the integration of the various effects. Although there is a large body of literature on specific aspects of 14-3-3 biology, not much is known on the coordinated aspects of 14-3-3 isoform expression, post-translational modifications, and subcellular localization. To address the question of isoform-specific differences, we carried out a comparative analysis of the patterns of expression, phosphorylation, and subcellular localization of the 14-3-3 beta, epsilon, sigma, tau, and zeta protein isoforms in transformed human amnion (AMA) cells. To validate as well as broaden our observations we analyzed the occurrence of the various isoforms in a large number of established cell lines and mammary and urothelial tissue specimens. Given the systematic approach we undertook and our application of isoform-discriminating technologies to the analysis of various cellular systems, we expect the data presented in this study to serve as an enabling resource for researchers working with 14-3-3 proteins.

15-prostaglandin dehydrogenase expression alone or in combination with ACSM1 defines a subgroup of the apocrine molecular subtype of breast carcinoma.

Established histopathological criteria divide invasive breast carcinomas into defined groups. Ductal of no specific type and lobular are the two major subtypes accounting for around 75 and 15% of all cases, respectively. The remaining 10% include rarer types such as tubular, cribriform, mucinous, papillary, medullary, metaplastic, and apocrine breast carcinomas. Molecular profiling technologies, on the other hand, subdivide breast tumors into five subtypes, basal-like, luminal A, luminal B, normal breast tissue-like, and ERBB2-positive, that have different prognostic characteristics. An additional subclass termed "molecular apocrine" has recently been described, but these lesions did not exhibit all the histopathological features of classical invasive apocrine carcinomas (IACs). IACs make up 0.5-3% of the invasive ductal carcinomas, and despite the fact that they are morphologically distinct from other breast lesions, there are presently no standard molecular criteria available for their diagnosis and as a result no precise information as to their prognosis. Toward this goal our laboratories have embarked in a systematic proteomics endeavor aimed at identifying biomarkers that may characterize and subtype these lesions as well as targets that may lead to the development of novel targeted therapies and chemoprevention strategies. By comparing the protein expression profiles of apocrine macrocysts and non-malignant breast epithelial tissue we have previously reported the identification of a few proteins that are specifically expressed by benign apocrine lesions as well as by the few IACs that were available to us at the time. Here we reiterate our strategy to reveal apocrine cell markers and present novel data, based on the analysis of a considerably larger number of samples, establishing that IACs correspond to a distinct molecular subtype of breast carcinomas characterized by the expression of 15-prostaglandin dehydrogenase alone or in combination with a novel form of acyl-CoA synthetase medium-chain family member 1 (ACSM1). Moreover we show that 15-prostaglandin dehydrogenase is not expressed by other breast cancer types as determined by gel-based proteomics and immunohistochemistry analysis and that antibodies against this protein can identify IACs in an unbiased manner in a large breast cancer tissue microarray making them potentially useful as a diagnostic aid.

Editorial.

May 2020 be a rewarding year of change. The recent commitment of the European Commission and policymakers to fight cancer in partnership is expected to bring forward the changes long required in the field. Molecular Oncology will stay at the forefront of all developments in the area of oncology by providing a flexible platform for European and International cancer research.

Towards a cancer mission in Horizon Europe: recommendations.

A comprehensive translational cancer research approach focused on personalized and precision medicine, and covering the entire cancer research-care-prevention continuum has the potential to achieve in 2030 a 10-year cancer-specific survival for 75% of patients diagnosed in European Union (EU) member states with a well-developed healthcare system. Concerted actions across this continuum that spans from basic and preclinical research through clinical and prevention research to outcomes research, along with the establishment of interconnected high-quality infrastructures for translational research, clinical and prevention trials and outcomes research, will ensure that science-driven and social innovations benefit patients and individuals at risk across the EU. European infrastructures involving comprehensive cancer centres (CCCs) and CCC-like entities will provide researchers with access to the required critical mass of patients, biological materials and technological resources and can bridge research with healthcare systems. Here, we prioritize research areas to ensure a balanced research portfolio and provide recommendations for achieving key targets. Meeting these targets will require harmonization of EU and national priorities and policies, improved research coordination at the national, regional and EU level and increasingly efficient and flexible funding mechanisms. Long-term support by the EU and commitment of Member States to specialized schemes are also needed for the establishment and sustainability of trans-border infrastructures and networks. In addition to effectively engaging policymakers, all relevant stakeholders within the entire continuum should consensually inform policy through evidence-based advice.

Towards a mission-oriented approach to cancer in Europe: an unmet need in cancer research policy.

Today, cancer is a significant challenge for society, healthcare systems and the growing number of affected patients and their families. This article argues that new paradigms and conditions for responsible science and innovation policy across the European Union (EU) require (i) the collective action of Research & Development institutions, (ii) a system approach to health systems, higher education and patient organizations, and (iii) new initiatives to encourage international cooperation across an enlarged Europe; no single country can successfully fight the disease(s) on its own. Recently, a cancer mission was proposed (Celis and Pavalski, ), the origins of which are rooted in the continuous efforts of the research community, cancer patient organizations, member states and the European Commission during nearly two decades to address the fragmentation and lack of coordination of European cancer research; these efforts led to the creation of Cancer Core Europe and Cancer Prevention Europe, consortia aimed at linking therapeutic and prevention geometries. Ultimately, the platform/infrastructure will be composed of networks of Comprehensive Cancer Centres and cancer research centres across Europe to reach the critical mass of expertise, patients and collaborative portfolio of projects that are necessary to promote science-driven and social innovations in the era of personalized (precision) cancer medicine. Employing a mission-oriented approach to achieve the goal of ensuring a long life expectancy for three out of four cancer patients by 2030 is likely to have a particularly positive impact on the way European citizens' value science and knowledge. It will change the lives of many families across Europe and beyond and should be oriented to ensure that Europe is at the forefront when it comes to quality of life. It is our collective responsibility to ensure that not a single person or region in Europe is left behind.

Cancer Core Europe: A translational research infrastructure for a European mission on cancer.

Cancer Core Europe is a European legal alliance consisting of seven leading cancer centres - most of them Comprehensive Cancer Centres (CCCs) - with a single portal system to engage in various research projects with partners. Cancer Core Europe was established to create a sustainable, high-level, shared research infrastructure platform hosting research collaborations and task forces (data sharing, clinical trials, genomics, immunotherapy, imaging, education and training, and legal and ethical issues), with a controlled expansion agenda. Translational cancer research covers the cancer research continuum from basic to preclinical to early clinical, late clinical, and outcomes research. Basic-preclinical research serves as the 'engine' for early clinical research by bridging the early translational research gap and is the primary and current focus of the consortium as exemplified by the launching of the Basket of Baskets trial, Europe's largest precision cancer medicine trial. Inspired by the creation of Cancer Core Europe, the prevention community established Cancer Prevention Europe, a consortium of ten cancer prevention centres aimed at supporting the complete prevention research continuum. Presently, Cancer Core Europe and Cancer Prevention Europe are integrating therapeutics and prevention strategies to address in partnership the widening cancer problem. By providing innovative approaches for cancer research, links to healthcare systems, development of quality-assured multidisciplinary cancer care, and assessment of long-term outcomes, the virtual infrastructure will serve as a hub to connect and interact with other centres across Europe and beyond. Together, Cancer Core Europe and Cancer Prevention Europe are prepared to function as a central engine to tackle, in collaboration with various partners, a potential 'mission on cancer' addressing the cancer burden.

Omics-based profiling of carcinoma of the breast and matched regional lymph node metastasis.

Axillary lymph node (ALN) status is currently used as an important clinical indicator of breast cancer prognosis. However, the molecular mechanisms underlying lymph node metastasis are poorly understood and the relationship between ALN metastasis and the primary tumor remains unclear. In an effort to reveal structural changes in the genome and related protein responses that may drive regional metastatic progression we have analyzed matched pairs of primary breast tumors and ALN metastases both at the genomic and proteomic levels using comparative genomic hybridization (CGH) array, quantitative high-resolution 2-D PAGE in combination with MS, and immunohistochemistry (IHC). Array CGH revealed a remarkable similarity in genomic aberration profiles between the matched primary tumors and the ALN metastases. Quantitative profiling of 135 known proteins also revealed striking similarities in their overall expression patterns, although we observed distinct changes in the levels of individual proteins in some sample pairs. The remarkable similarities of the overall genomic and proteomic profiles between primary tumors and matched ALN metastases are taken to suggest that, in general, key biological characteristics of the primary breast tumor are maintained in the corresponding lymph node metastases. Given that the omics-based technologies are oblivious to changes that only occur in minor cellular subsets we validated the proteomic data using IHC, which provides protein expression information with a valuable topological component. Besides confirming the omics-derived data, the IHC analysis revealed that in two cases the ALN metastases may have been derived from a distinct minor cell subpopulation present in the primary tumor rather than from the bulk of it.

European Academy of Cancer Sciences - position paper.

The European Academy of Cancer Sciences (EACS) is an independent advisory body of well-recognised medical specialists and researchers striving to create a compelling interactive continuum of cancer research, from innovative basic research to implementation of state-of-the-art evidence-based cancer care and prevention. Achieving the above will entail bridging high-quality basic and preclinical cancer research to research on prevention, early detection and therapeutics as well as improving coordination of translational research efforts across Europe. The latter is expected to be expedited through quality assuring translational cancer research in Comprehensive Cancer Centres - entities that link research with the healthcare system - and networks of cancer research centres. Achieving a critical mass of expertise, resources and patients is crucial. Improving late translational research, which involves clinical studies to assess effectiveness, and added value for the health care is also a high priority. Both high-quality Big Data collections and the intelligent use of these data will promote innovation in cancer research and support outcomes research to assess clinical utility, quality of cancer care and long-term follow-up of treated patients. The EACS supports the mission-oriented approach recently proposed by the European Commission in Horizon Europe to deal with major challenges and would like to persuade the EU and its member states to formally launch a mission in cancer to boost and streamline the cancer research continuum in Europe. Building a coherent translational cancer research continuum with a focus on patients and individuals at risk will require, however, foresight as well as the extensive and continuous provision of evidence-based advice to inform policy.

Cancer Core Europe: A European cancer research alliance realizing a research infrastructure with critical mass and programmatic approach to cure cancer in the 21st century.

Translational cancer research covers the whole cancer research continuum from basic to preclinical to early clinical, late clinical and outcomes research. Basic-preclinical research is the "engine" for early clinical research bridging the early translational research gap. Cancer Core Europe has been created to construct a sustainable, high level, shared research infrastructure platform with research collaborations and taskforces (data sharing, clinical trials, genomics, immunotherapy, imaging, legal & ethical problems, and education & training) having representatives from all seven member centres, in a controlled expansion model. In parallel, a consortium of ten cancer prevention centres was established, Cancer Prevention Europe, to support the complete cancer prevention research continuum. Cancer Core Europe is launching at present the Basket of Baskets trial, which is the largest personalized cancer medicine trial effort in Europe. At present, Cancer Core Europe and Cancer Prevention Europe are in the process of integrating therapeutics and prevention strategies to address in partnership the increasing cancer problem. By offering innovative approaches for cancer research, links to the healthcare systems, development of quality-assured multidisciplinary cancer care, as well as the assessment of long-term outcomes, the infrastructure is expected to serve as a hub to connect with other centres in Europe as well as on other continents. In this manner Cancer Core Europe and Cancer Prevention Europe prepare to tackle the "Mission on Cancer", with infrastructure and proofs of concept for therapeutics and prevention, research for assessment of effectiveness, health economics and added value for patients and the healthcare systems.

A mission-oriented approach to cancer in Europe: a joint mission/vision 2030.

By combining innovative prevention and treatment strategies in a sustainable state-of-the-art virtual European cancer centre/infrastructure, it will be possible by 2030 to achieve a long-term survival of 3 out of 4 cancer patients in countries with well-developed healthcare systems. Furthermore, the proposed concerted actions will pave the way to handling the economic and social inequalities in countries with less developed systems. These efforts will also ensure that in the long-run, science-driven and social innovations reach patients across the healthcare systems in Europe.

Molecular pathology of breast apocrine carcinomas: a protein expression signature specific for benign apocrine metaplasia.

Breast cancer is a heterogeneous disease that encompasses a wide range of histopathological types including: invasive ductal carcinoma, lobular carcinoma, medullary carcinoma, mucinous carcinoma, tubular carcinoma, and apocrine carcinoma among others. Pure apocrine carcinomas represent about 0.5% of all invasive breast cancers according to the Danish Breast Cancer Cooperative Group Registry, and despite the fact that they are morphologically distinct from other breast lesions, there are at present no standard molecular criteria available for their diagnosis. In addition, the relationship between benign apocrine changes and breast carcinoma is unclear and has been a matter of discussion for many years. Recent proteome expression profiling studies of breast apocrine macrocysts, normal breast tissue, and breast tumours have identified specific apocrine biomarkers [15-hydroxyprostaglandin dehydrogenase (15-PGDH) and hydroxymethylglutaryl coenzyme A reductase (HMG-CoA reductase)] present in early and advanced apocrine lesions. These biomarkers in combination with proteins found to be characteristically upregulated in pure apocrine carcinomas (psoriasin, S100A9, and p53) provide a protein expression signature distinctive for benign apocrine metaplasias and apocrine cystic lesions. These studies have also presented compelling evidence for a direct link, through the expression of the prostaglandin degrading enzyme 15-PGDH, between early apocrine lesions and pure apocrine carcinomas. Moreover, specific antibodies against the components of the expression signature have identified precursor lesions in the linear histological progression to apocrine carcinoma. Finally, the identification of proteins that characterize the early stages of mammary apocrine differentiation such as 15-PGDH, HMG-CoA reductase, and cyclooxygenase 2 (COX-2) has opened a window of opportunity for pharmacological intervention, not only in a therapeutic manner but also in a chemopreventive setting. Here we review published and recent results in the context of the current state of research on breast apocrine cancer.

Towards discovery-driven translational research in breast cancer.

Discovery-driven translational research in breast cancer is moving steadily from the study of cell lines to the analysis of clinically relevant samples that, together with the ever increasing number of novel and powerful technologies available within genomics, proteomics and functional genomics, promise to have a major impact on the way breast cancer will be diagnosed, treated and monitored in the future. Here we present a brief report on long-term ongoing strategies at the Danish Centre for Translational Breast Cancer Research to search for markers for early detection and targets for therapeutic intervention, to identify signalling pathways affected in individual tumours, as well as to integrate multiplatform 'omic' data sets collected from tissue samples obtained from individual patients. The ultimate goal of this initiative is to coalesce knowledge-based complementary procedures into a systems biology approach to fight breast cancer.

Human proteomic databases: a powerful resource for functional genomics in health and disease.

Decoding of the genome information in terms of regulation and function will be the next great challenge in the life sciences in this millennium and indeed, today we are experiencing a rapid explosion of technology for the high throughput expression analysis of genes and their products (functional genomics). In particular, the field of proteomics is booming as proteins are often the functional molecules and represent important targets for the pharmaceutical industry. The proteomic technology is complex, and comprises a plethora of state-of-the-art techniques to resolve, identify and detect their interacting partners, as well as to store and communicate protein information in comprehensive two-dimensional polyacrylamide gel electrophoresis (2D PAGE) databases. Besides annotating the genome, these databases will offer a global approach to the study of gene expression both in health and disease. Here, we review the current status of human 2D PAGE databases that we are systematically constructing for the study of bladder cancer and skin ageing.

Impact of proteomics on bladder cancer research.

Detecting bladder cancer at an early stage and predicting how a tumor will behave and act in response to therapy, as well as the identification of new targets for therapeutic intervention, are among the main areas of research that will benefit from the current explosion in the number of powerful technologies emerging within proteomics. The purpose of this article is to briefly review what has been achieved to date using proteomic technologies and to bring forward novel strategies - based on the analysis of clinically relevant samples - that promise to accelerate the translation of basic discoveries into the daily clinical practice.

A personal account of the early stages of proteomics at Aarhus University.

This article is part of a Special Issue entitled: 20 years of Proteomics in memory of Viatliano Pallini. Guest Editors: Luca Bini, Juan J. Calvete, Natacha Turck, Denis Hochstrasser and Jean-Charles Sanchez.