| 1. |
- Agnarsdóttir, Margrét, 1970-
(författare)
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Biomarker Discovery in Cutaneous Malignant Melanoma : A Study Based on Tissue Microarrays and Immunohistochemistry
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The incidence of cutaneous malignant melanoma has increased dramatically in Caucasians the last few decades, an increase that is partly explained by altered sun exposure habits. For the individual patient, with a localized disease, the tumor thickness of the excised lesion is the most important prognostic factor. However, there is a need to identify characteristics that can place patients in certain risk groups. In this study, the protein expression of multiple proteins in malignant melanoma tumors was studied, with the aim of identifying potential new candidate biomarkers. Representative samples from melanoma tissues were assembled in a tissue microarray format and protein expression was detected using immunohistochemistry. Multiple cohorts were used and for a subset of proteins the expression was also analyzed in melanocytes in normal skin and in benign nevi. The immunohistochemical staining was evaluated manually and for part of the proteins also with an automated algorithm. The protein expression of STX7 was described for the first time in tumors of the melanocytic lineage. Stronger expression of STX7 and SOX10 was seen in superficial spreading melanomas compared with nodular malignant melanomas. An inverse relationship between STX7 expression and T-stage was seen and between SOX10 expression and T-stage and Ki-67, respectively. In a population-based cohort the expression of MITF was analyzed and found to be associated with prognosis. Twenty-one potential biomarkers were analyzed using bioinformatics tools and a protein signature was identified which had a prognostic value independent of T-stage. The protein driving this signature was RBM3, a protein not previously described in malignant melanoma. Other markers included in the signature were MITF, SOX10 and Ki-67. In conclusion, the protein expression of numerous potential biomarkers was extensively studied and a new prognostic protein panel was identified which can be of value for risk stratification.
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| 2. |
- Andersson, Sandra, 1978-
(författare)
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Validation of antibodies for tissue based immunoassays
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In situ protein detection in human tissues using antibodies reveals the cellular protein localization, and affinity-based proteomic studies can help to discover proteins involved in the development of diseases. However, antibodies often suffer from cross-reactivity, and the lack of positive and negative tissue controls for uncharacterized proteins complicates the mapping of the proteome. The aim of this thesis is thus to improve the methodology for validating antibodies used for immunostaining on formalin-fixed paraffin-embedded tissues.Two of the papers include comparisons between mRNA-expression and immunostaining of corresponding protein. In paper I, ISH and IHC staining patterns were compared on consecutive TMA-slides. The study of well-characterized genes showed that ISH could be used for validation of antibodies. ISH was further used for antibody evaluation, and could validate four out of nine antibodies showing potentially interesting staining patterns. In paper III, transcriptomic data generated by RNA-sequencing were used to identify tissue specific expression in lymphohematopoietic tissues. An increased expression in one or more of these tissues compared to other tissue types was seen for 693 genes, and these were further compared to the staining patterns of corresponding proteins in tissues.Antibody labeling is necessary for many immunoassays. In paper II, two techniques for antibody-biotinylation were compared, aiming to find a stringent labeling method for antibodies used for immunostaining on TMAs. The ZBPA-method, binding specifically to Fc-part of antibodies, was found to be superior to the Lightning Link-biotinylation kit targeting amine groups, since labeling of amine groups on stabilizing proteins in the antibody buffer causes unspecific staining.The localization of the estrogen receptor beta (ERβ) in human normal and cancer tissues was studied in paper IV. Thorough evaluation of 13 antibodies using positive and negative control cell lines showed that only one antibody, PPZ0506, is specific for ERβ in all three immunoassays used. Contradictory to previously published data, tissue profiling using PPZ0506 showed that ERβ is expressed in a limited number of normal and cancer tissues.In conclusion, the present investigations present tools for validation of antibodies used for large-scale studies of protein expression in tissues.
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| 3. |
- Backman, Max, 1987-
(författare)
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Spatial immune analyses in clinical cancer tissue
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cancer is a leading cause of premature death and lung cancer is the deadliest cancer type, with non-small cell lung cancer (NSCLC) representing 85% of lung cancer cases. Despite promising development in cancer treatment in recent decades, overall prognosis is poor. The aim of this thesis was to explore novel techniques in protein visualization in clinical cancer tissue to better our understanding of cancer immunity and to discover new biomarkers for improved cancer diagnostics.In Paper I traditional immunohistochemistry (IHC) was compared to the in-situ proximity ligation assay (isPLA). Both techniques were applied to stain 12 proteins in 39 cell lines and 37 tissue types. Two different antibodies were used in the IHC assay and in the isPLA, where binding by both antibodies is required to generate detection signals. The comparison of staining patterns showed that the isPLA presents a valuable alternative to traditional IHC.In Paper II cancer tissue from 357 NSCLC patients was immunophenotyped through IHC annotations of 11 different immune markers. A distinct group of cases with a signature of NK cells and/or plasma cells had favorable prognosis despite significantly lower T-cell activation signatures. This study provides a detailed description of the immune landscape in NSCLC, extending previous concepts, and highlights plasma and NK-cells as potential biomarkers for further validation.In Paper III a multiplex-multispectral pipeline was established to explore three immune marker panels in a NSCLC cohort, spatially quantifying 13 immune cell types. The immune composition of NSCLC was analyzed for the prognostic relevance of immune cell coordination. Cell densities and distances were found to contribute independently to prognosis, indicating that spatial information on local immune cell infiltration is crucial for understanding tumor immunity.In Paper IV an extensive characterization of the immune cell landscape of colon cancer identified a prognostic signature based on the ratio of CD8+ lymphocytes to CD68+CD163+ macrophages. This signature was superior to the state-of-the-art ‘Immunoscore’, and was also associated with longer survival when analyzed in other common cancer types. This presents a promising immunological biomarker that warrants further validation as a prognostic and predictive signature in common cancers.In summary, this thesis presents an in-depth study of immune cell infiltration in several cancer types to better understand cancer immunity. Through novel techniques and spatial metrics, we describe immunophenotypes that might contribute to cancer classification and prognostication. The identified immune phenomena may also present alternative treatment targets to overcome resistance to immunotherapy.
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| 4. |
- Bergman, Julia, 1983-
(författare)
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Aspects of Gene Expression Profiling in Disease and Health
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis is to in various ways explore protein expression in human normal tissue and in cancer and to apply that knowledge in biomarker discovery.In Paper I the prognostic significance of RNA-binding motif protein 3 (RBM3) is explored in malignant melanoma. To further evaluate the prognostic significance of RBM3 expression was assessed in 226 incident cases of malignant melanoma from the prospective populationbased cohort study Malmö Diet and Cancer Study using tissue microarray technique (TMA). RBM3 was shown to be down regulated in metastatic melanoma and high nuclear expression in the primary tumor was an independent marker of prolonged over all survival. As a tool to facilitate clinical biomarker studies the Human Protein Atlas has created a tissue dictionary as an introduction to human histology and histopathology. In Paper II this work is introduced.A cancer diagnosis can be a complex process with difficulties of establishing tumor type in localized disease or organ of origin in generalized disease. Immunohistochemically assisted diagnosis of cancer is common practice among pathologists where its application combined with known protein expression profiles of different cancer types, can strengthen or help dismiss a suspected diagnosis. In Paper III the diagnostic performance of 27 commonly used antibodies are tested in a predominantly metastatic, multicancer cohort using TMA technique. Overall these 27 diagnostic markers showed a low sensitivity and specificity for its intended use, highlighting the need for novel, more specific markers.Breast, ovarian, endometrial and ovarian cancers affect predominantly women. Differential diagnostics between these cancer types can be challenging. In Paper IV an algorithm, based on six different IHC markers, to differentiate between these cancer types is presented. A new diagnostic marker for breast cancer, namely ZAG is also introduced.In Paper V the transcriptomic landscape of the adrenal gland is explored by combining a transcriptomic approach with a immunohistochemistry based proteomic approach. In the adrenal gland we were able to detect 253 genes with an elevated pattern of expression in the adrenal gland, as compared to 31 other normal human tissue types analyzed. This combination of a transcriptomic and immunohistochemical approach provides a foundation for a deeper understanding of the adrenal glands function and physiology.
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| 5. |
- Elfving, Hedvig
(författare)
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Improving the diagnostic armamentarium of lung cancer
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lung cancer is the leading cause of cancer-related death globally, with non-small cell lung cancer (NSCLC) constituting 85% of cases. The introduction of immunotherapies and targeted therapies have dramatically improved the prognosis and outcome for a subset of patients, and stressed the development of diagnostic tools for effective patient selection. This thesis addresses different aspects of current and future diagnostic strategies in NSCLC patients.In Paper I, an immunohistochemical assay targeting the neurotropic tropomyosin receptor kinase (NTRK) was evaluated on tissue microarrays (TMAs) from a well-characterized NSCLC cohort. Although a few cases showed positive staining, none were positive in the reference molecular testing, highlighting the rarity of this targetable aberration and underscoring the value of cost-effective screening methods.In Paper II, paired patient samples (biopsy, TMA, and surgical specimen) were evaluated regarding the immunohistochemical staining for PD-L1. The results indicated a strong correlation between the PD-L1 expression on biopsy and TMA compared with the tumor whole slide, suggesting that tumor heterogeneity has minor relevance for PD-L1 evaluation.In Paper III, paired tissue samples (biopsy, TMA, and surgical specimen) were evaluated regarding infiltrating CD3+ immune cells. Only weak correlation was found between the biopsies and tumor whole slide, while the agreement between the whole slide and TMA was higher. These results question the use of biopsies for immune cell quantification, while supporting the TMA as a reliable tool in cancer research.In Paper IV, the amount and distribution of tertiary lymphoid structures (TLS) was annotated on scanned tumor whole slides. TLS were present in most of the tumors and correlated with the abundance of specific immune cell subsets. Higher number of TLS were associated with longer survival, particularly in adenocarcinomas. High tumor mutational burden was associated with higher numbers of periphery TLS. These results provide a rationale for using TLS metrics as a diagnostic marker for NSCLC patients undergoing surgical resection.In summary, this thesis addresses challenges in prognostic and predictive lung cancer diagnostics in the areas of targeted therapy and immunotherapy. The results provide crucial insights into tumor heterogeneity that may impact clinical decision-making and aid scientists in selecting appropriate tissue sources for translational and clinical cancer research.
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| 6. |
- Lindskog Bergström, Cecilia, 1981-
(författare)
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Tissue Microarrays for Analysis of Expression Patterns
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Proteins are essential building blocks in every living cell, and since the complete human genome was sequenced in 2004, researchers have attempted to map the human proteome, which is the functional representation of the genome. One such initiative is the Human Protein Atlas programme (HPA), which generates monospecific antibodies towards all human proteins and uses these for high-throughput tissue profiling on tissue microarrays (TMAs). The results are publically available at the website www.proteinatlas.org.In this thesis, TMAs were used for analysis of expression patterns in various research areas. Different search queries in the HPA were tested and evaluated, and a number of potential biomarkers were identified, e.g. proteins exclusively expressed in islets of Langerhans, but not in exocrine glandular cells or other abdominal organs close to pancreas. The identified candidates were further analyzed on TMAs with pancreatic tissues from normal and diabetic individuals, and colocalization studies with insulin and glucagon revealed that several of the investigated proteins (DGCR2, GBF1, GPR44 and SerpinB10) appeared to be beta cell specific. Moreover, a set of proteins differentially expressed in lung cancer stroma was further analyzed on a clinical lung cancer cohort in the TMA format, and one protein (CD99) was significantly associated with survival. In addition, TMAs with tissue samples from different species were generated, e.g. for mapping of influenza virus attachment in various human and avian tissues. The results showed that the gull influenza virus H16N3 attached to human respiratory tract and eye, suggesting possible transmission of the virus between gull and human. TMAs were also used for analysis of protein expression differences between humans and other primates, and two proteins (TCF3 and SATB2) proved to be significantly differentially expressed on the human lineage at both the protein level and the RNA level. In conclusion, this thesis exemplifies the potential of the TMA technology, which can be used for analysis of expression patterns in a large variety of research fields, such as biomarker discovery, influenza virus research or further understanding of human evolution.
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| 7. |
- Paavilainen, Linda, 1979-
(författare)
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Validation of antibodies for protein profiling : A study using immunohistochemistry on tissue microarrays
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The field of proteomics has rapidly expanded due to the completion of the human genome sequence. This thesis validates affinity-purified monospecific antibodies of polyclonal origin, for protein profiling in a broad spectrum of normal tissues and cells. Validation of antibodies is crucial for development of reliable binders for target proteins and this thesis evaluates the generation and application of large sets of msAbs in different settings. MsAbs were generated towards recombinant Protein Epitope Signature Tag (PrEST) antigens using a stringent affinity-purification strategy, presented in the first study. The specificity of msAbs was studied using reverse phase protein arrays and immunohistochemistry (IHC), and results presented over 90% success rate in the protein array analysis. In IHC, 81% of the msAbs displayed apparent specific staining in normal tissues. MsAbs were also compared with commercial analogs (cAbs) using IHC and Western blot. Results presented similar outcome between msAbs and cAbs in both applications, although interpretation suggested more extensive IHC staining patterns with msAbs than with monoclonal analogs. For antibody validation, an approach called paired antibodies was presented and involved the generation of two msAbs towards non-overlapping epitopes on the same protein. Similarities in protein detection between paired antibodies were studied using three different antibody-based methods. Similar results were observed in several applications, indicating that this strategy can be a useful tool for studying known and unknown proteins. Given the reliability of msAbs, they were also applied in a study investigating the impact of tissue fixatives on protein detection. The study showed that different fixation mechanisms appeared to affect protein recognition by indicating that aldehyde-based fixation, e.g. induced by neutral buffered formalin, was preferred for tissues used in IHC and non-aldehyde based fixation was applicable for tissues used in protein extraction analysis and Western blotting. Conclusively, validation results suggest that msAbs are reliable affinity binders that can be used as valuable tools for proteome-wide protein profiling in tissues and cells.
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