| 1. |
- Darai-Ramqvist, Eva, et al.
(författare)
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Microenvironment-dependent phenotypic changes in a SCID mouse model for malignant mesothelioma
- 2013
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Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims: Malignant mesothelioma is an aggressive, therapy-resistant tumor. Mesothelioma cells may assume an epithelioid or a sarcomatoid phenotype, and presence of sarcomatoid cells predicts poor prognosis. In this study, we investigated differentiation of mesothelioma cells in a xenograft model, where mesothelioma cells of both phenotypes were induced to form tumors in severe combined immunodeficiency mice.Methods: Xenografts were established and thoroughly characterized using a comprehensive immunohistochemical panel, array comparative genomic hybridization (aCGH) of chromosome 3, fluorescent in situ hybridization, and electron microscopy.Results: Epithelioid and sarcomatoid cells gave rise to xenografts of similar epithelioid morphology. While sarcomatoid-derived xenografts had higher growth rates, the morphology and expression of differentiation-related markers was similar between xenografts derived from both phenotypes. aCGH showed a convergent genotype for both xenografts, resembling the original aggressive sarcomatoid cell sub-line.Conclusion: Human mesothelioma xenografts from sarcomatoid and epithelioid phenotypes converged to a similar differentiation state, and genetic analyses suggested that clonal selection in the mouse microenvironment was a major contributing factor. This thoroughly characterized animal model can be used for further studies of molecular events underlying tumor cell differentiation.
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| 2. |
- Dobra, Katalin
(författare)
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Malignant mesothelioma : an experimental study with emphasis on proteoglycans in mesothelial cell growth and differentiation
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Malignant mesothelioma is a highly aggressive tumor with median survival ranging from 4 to 12 months and, despite intense therapeutical efforts, it is invariably fatal. Mesothelioma cells are unique in the sense that they possess a biphasic growth potential and can be stimulated by serum growth factors to differentiate into stable epithelial or fibrous phenotypes. The prognosis of this tumor varies greatly depending on the differences in growth pattern, the most important predictor of poor prognosis being a fibrous phenotype. To study the molecular basis of mesothelial differentiation, we used benign and malignant mesothelial cells in various stages of phenotypic differentiation. In order to evaluate the impact of proteoglycans (PG) on this process, a series of PGs were analyzed by semi quantitative reversed transcriptase polymerase chain reaction. The cells with epithelial phenotype showed increased expression of syndecan-2, syndecan-4 and hyaluronan synthase, and fibroblast-like cells expressed more matrix PGs: versican, decorin and biglycan. The PG profile may serve as a "fingerprint", and reflect the maturation of mesothelial cells. The functional importance of syndecans in mesothelial differentiation was further shown by antisense targeting; down-regulation of each particular syndecan caused a loss of epithelial morphology, syndecans - 1 and -4 being also essential for cell adhesion. The differentiation of mesothelioma cells was influenced by treatment with various growth factors (TGF-beta2, EGF, FGF-2, IGF-I and PDGF-BB). These factors affected the proliferation and morphology of mesothelioma cells to various extents, and the PG profile changed, in parallel, with an induced epithelial-mesenchymal transition. Exposure to EG17 and IGF-I caused a fibroblast-like morphology simultaneously with a reduction in the syndecan expression levels. At the same time, the levels of shed syndecan-1 increased in the culture medium. The involvement of other regulatory molecules in mesothelioma differentiation was assessed by subtractive hybridization, which has revealed a limited number of genes being differentially expressed between cells of epithelial or fibrous phenotypes. Most of these genes were recovered from the epithelial cells, which may indicate a more mature phenotype. The expression level of thioredoxin reductase, a small redox-active protein involved in drug resistance, was extremely high in both cell sub-lines, and may reflect the generic insensitivity of mesotheliomas to chemotherapy. Although syndecans play a major role in regulating cell morphology, little is known about their subcellular distribution. Using confocal laser microscopy we found a substantial proportion of syndecans at intracellular locations, and syndecan-1 accumulated in the nucleus in a time-dependent manner. There was a close spatial relation of syndecans to tubulin in both interphase and mitotic cells. Vinblastine treatment interfered with the nuclear transport, and syndecan-1 and tubulin co-polymerize in paracrystalline occlusion bodies, in parallel with impaired nuclear transport. These findings suggest a tubulin-mediated transport mechanism. TGF-beta2 reduced the proliferation rate of mesothelioma cells, concomitantly with a delay in nuclear transport of syndecan-1. These data show that all syndecans are involved in maintaining the epithelial morphology, and that various amounts and translocation of syndecans may participate in molecular switches that regulate cell differentiation and proliferation. The above mechanisms may represent crucial steps, and possible future targets for therapy, that can be used to improve the management of patients with malignant mesothelioma.
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| 3. |
- Ericson Lindquist, Kajsa, et al.
(författare)
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Difficulties in diagnostics of lung tumours in biopsies : an interpathologist concordance study evaluating the international diagnostic guidelines
- 2022
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Ingår i: Journal of Clinical Pathology. - : BMJ Publishing Group Ltd. - 0021-9746 .- 1472-4146. ; 75:5, s. 302-309
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Accurate and reliable diagnosis is essential for lung cancer treatment. The study aim was to investigate interpathologist diagnostic concordance for pulmonary tumours according to WHO diagnostic criteria.METHODS: Fifty-two unselected lung and bronchial biopsies were diagnosed by a thoracic pathologist based on a broad spectrum of immunohistochemical (IHC) stainings, molecular data and clinical/radiological information. Slides stained with H&E, thyroid transcription factor-1 (TTF-1) clone SPT24 and p40 were scanned and provided digitally to 20 pathologists unaware of reference diagnoses. The pathologists independently diagnosed the cases and stated if further diagnostic markers were deemed necessary.RESULTS: In 31 (60%) of the cases, ≥80% of the pathologists agreed with each other and with the reference diagnosis. Lower agreement was seen in non-small cell neuroendocrine tumours and in squamous cell carcinoma with diffuse TTF-1 positivity. Agreement with the reference diagnosis ranged from 26 to 45 (50%-87%) for the individual pathologists. The pathologists requested additional IHC staining in 15-44 (29%-85%) of the 52 cases. In nearly half (17 of 36) of the malignant cases, one or more pathologist advocated for a different final diagnosis than the reference without need of additional IHC markers, potentially leading to different clinical treatment.CONCLUSIONS: Interpathologist diagnostic agreement is moderate for small unselected bronchial and lung biopsies based on a minimal panel of markers. Neuroendocrine morphology is sometimes missed and TTF-1 clone SPT24 should be interpreted with caution. Our results suggest an intensified education need for thoracic pathologists and a more generous use of diagnostic IHC markers.
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| 4. |
- Javadi, Joman, et al.
(författare)
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Syndecan-1 Overexpressing Mesothelioma Cells Inhibit Proliferation, Wound Healing, and Tube Formation of Endothelial Cells
- 2021
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 13:4
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary The transmembrane proteoglycan syndecan-1 (SDC-1) is an important mediator of cell-matrix interactions. The heparan sulfate side-chains of SDC-1 can bind to a multitude of growth factors, cytokines, and chemokines, thereby regulating a plethora of physiological and pathological processes, including angiogenesis. The extracellular region of SDC-1 can be released from the cell surface by the action of sheddases including matrix metalloproteinase-7 and 9, resulting in a soluble protein that is still active and can act as a competitive activator or inhibitor of the cell surface receptor. Accelerated shedding and loss of cell surface SDC-1 is associated with epithelial to mesenchymal transition (EMT) and achievement of a more invasive phenotype in malignant mesothelioma (MM). Transfection with SDC-1 reverts the morphology in epithelioid direction and inhibits the proliferation and migration of MM cells. This study aimed to investigate the role of SDC-1 in angiogenesis. We demonstrate that overexpression and silencing of SDC-1 alters the secretion of angiogenic proteins in MM cells. Upon SDC-1 overexpression, several factors collectively inhibit the proliferation, wound closure, and tube formation of endothelial cells, whereas SDC-1 silencing only affects wound healing. Malignant mesothelioma (MM) is an aggressive tumor of the serosal cavities. Angiogenesis is important for mesothelioma progression, but so far, anti-angiogenic agents have not improved patient survival. Our hypothesis is that better understanding of the regulation of angiogenesis in this tumor would largely improve the success of such a therapy. Syndecan-1 (SDC-1) is a transmembrane heparan sulfate proteoglycan that acts as a co-receptor in various cellular processes including angiogenesis. In MM, the expression of SDC-1 is generally low but when present, SDC-1 associates to epithelioid differentiation, inhibition of tumor cell migration and favorable prognosis, meanwhile SDC-1 decrease deteriorates the prognosis. In the present study, we studied the effect of SDC-1 overexpression and silencing on MM cells ability to secrete angiogenic factors and monitored the downstream effect of SDC-1 modulation on endothelial cells proliferation, wound healing, and tube formation. This was done by adding conditioned medium from SDC-1 transfected and SDC-1 silenced mesothelioma cells to endothelial cells. Moreover, we investigated the interplay and molecular functional changes in angiogenesis in a co-culture system and characterized the soluble angiogenesis-related factors secreted to the conditioned media. We demonstrated that SDC-1 over-expression inhibited the proliferation, wound healing, and tube formation of endothelial cells. This effect was mediated by a multitude of angiogenic factors comprising angiopoietin-1 (Fold change +/- SD: 0.65 +/- 0.07), FGF-4 (1.45 +/- 0.04), HGF (1.33 +/- 0.07), NRG1-beta 1 (1.35 +/- 0.08), TSP-1 (0.8 +/- 0.02), TIMP-1 (0.89 +/- 0.01) and TGF-beta 1 (1.35 +/- 0.01). SDC-1 silencing increased IL8 (1.33 +/- 0.06), promoted wound closure, but did not influence the tube formation of endothelial cells. Pleural effusions from mesothelioma patients showed that Vascular Endothelial Growth Factor (VEGF) levels correlate to soluble SDC-1 levels and have prognostic value. In conclusion, SDC-1 over-expression affects the angiogenic factor secretion of mesothelioma cells and thereby inhibits endothelial cells proliferation, tube formation, and wound healing. VEGF could be used in prognostic evaluation of mesothelioma patients together with SDC-1.
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| 5. |
- Keller, Maureen, et al.
(författare)
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Cytoskeletal Organization Correlates to Motility and Invasiveness of Malignant Mesothelioma Cells
- 2021
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 13:4
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Tidskriftsartikel (refereegranskat)abstract
- Malignant mesothelioma (MM) is a rare but highly aggressive cancer that primarily originates from the pleura, peritoneum or pericardium. There is a well-established link between asbestos exposure and progression of MM. Direct invasion of the surrounding tissues is the main feature of MM, which is dependent on dysregulated communication between the mesothelium and the microenvironment. This communication is dependent on the dynamic organization of the cytoskeleton. We have analyzed the organization and function of key cytoskeletal components in MM cell lines of increasing malignancies measured as migratory and invasive properties, and we show that highly malignant and invasive MM cells have an organization of the actin filament and vimentin systems that is distinct from the less malignant MM cell lines. In addition, the Hippo tumor suppressor pathway was inactivated in the invasive MM cells, which was seen as increased YAP nuclear localization.
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| 6. |
- Lindquist, Kajsa Ericson, et al.
(författare)
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Real-world diagnostic accuracy and use of immunohistochemical markers in lung cancer diagnostics
- 2021
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Ingår i: Biomolecules. - : MDPI AG. - 2218-273X. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Accurate and reliable diagnostics are crucial as histopathological type influ-ences selection of treatment in lung cancer. The aim of this study was to evaluate real-world accuracy and use of immunohistochemical (IHC) staining in lung cancer diagnostics. Materials and Methods: The diagnosis and used IHC stains for small specimens with lung cancer on follow-up resection were retrospectively investigated for a 15-month period at two major sites in Sweden. Additionally, 10 pathologists individually suggested diagnostic IHC staining for 15 scanned bronchial and lung biopsies and cytological specimens. Results: In 16 (4.7%) of 338 lung cancer cases, a discordant diagnosis of potential clinical relevance was seen between a small specimen and the fol-low-up resection. In half of the cases, there was a different small specimen from the same investi-gational work-up with a concordant diagnosis. Diagnostic inaccuracy was often related to a squa-mous marker not included in the IHC panel (also seen for the scanned cases), the case being a neu-roendocrine tumor, thyroid transcription factor-1 (TTF-1) expression in squamous cell carcinomas (with clone SPT24), or poor differentiation. IHC was used in about 95% of cases, with a higher number of stains in biopsies and in squamous cell carcinomas and especially neuroendocrine tumors. Pre-surgical transthoracic samples were more often diagnostic than bronchoscopic ones (72–85% vs. 9–53% for prevalent types). Conclusions: Although a high overall diagnostic accuracy of small specimens was seen, small changes in routine practice (such as consequent inclusion of p40 and TTF-1 clone 8G7G3/1 in the IHC panel for non-small cell cancer with unclear morphology) may lead to improvement, while reducing the number of IHC stains would be preferable from a time and cost perspective.
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| 7. |
- Mansour, Mohammed S I, et al.
(författare)
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Comparison of immunohistochemical mesothelial biomarkers in paired biopsies and effusion cytology cell blocks from pleural mesothelioma
- 2023
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Ingår i: Cytopathology. - 1365-2303. ; 34:5, s. 456-465
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Traditionally, the diagnosis of pleural mesothelioma is based on histological material. Minimally invasive effusion cytology specimens are an alternative that, like biopsies, require ancillary analyses. Validation of immunohistochemical (IHC) analyses on cytology, including the surrogate markers for molecular alterations BAP1 and MTAP, is of interest.METHODS: IHC for eight different markers was performed on 59 paired formalin-fixed, paraffin-embedded pleural biopsies and pleural effusion cell blocks with mesothelioma. Immunoreactivity in ≥10% of tumour cells was considered positive/preserved. The concordance between histological and cytological materials was assessed.RESULTS: The overall percentage of agreement between the histological epithelioid component in 58 biopsies and paired cell blocks was 93% for calretinin, 98% for CK5, 97% for podoplanin, 90% for WT1, 86% for EMA, 100% for desmin, 91% for BAP1, and 72% for MTAP. For 11 cases with biphasic or sarcomatoid histology, the concordance between cytology and the histological sarcomatoid component was low for calretinin, CK5, and WT1 (all ≤45%). For the whole cohort, loss of both BAP1 and MTAP was seen in 40% while both markers were preserved in 11% of the biopsies for epithelioid histology. The corresponding numbers were 54% and 8%, respectively, for the paired cell blocks.CONCLUSIONS: Generally, a high concordance for IHC staining was seen between paired biopsies and pleural effusion cell blocks from mesotheliomas, but the somewhat lower agreement for WT1, EMA, and especially MTAP calls for further investigation and local quality assurance. The lower concordance for the sarcomatoid subtype for some markers may indicate biological differences.
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| 8. |
- Mansour, Mohammed S I, et al.
(författare)
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Higher concordance of PD-L1 expression between biopsies and effusions in epithelioid than in nonepithelioid pleural mesothelioma
- 2021
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Ingår i: Cancer Cytopathology. - : Wiley. - 1934-6638 .- 1934-662X. ; 129:6, s. 468-478
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Malignant mesothelioma (MM) is a therapy-resistant tumor, often causing an effusion. Drugs targeting the programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway have shown promising results, but assessment of PD-L1 expression to select patients for therapy has mainly been performed on histologic tissue samples. In a previous study, we showed that MM effusions are suitable for PD-L1 assessment with results comparable to those reported in histologic studies, but no studies have compared PD-L1 expression in histologic and cytologic samples.METHODS: PD-L1 expression was determined immunohistochemically (clone 28-8) in 61 paired samples of effusions and biopsies from patients with pleural MM, obtained at the time of diagnosis. Only cases with >100 tumor cells were included. Membranous staining in tumor cells was considered positive at ≥1%, >5%, >10%, and >50% cutoff levels.RESULTS: Of 61 histologic samples, PD-L1 expression was found in 28 and 7 samples at ≥1% and >50% cutoffs, respectively; the corresponding figures for cytology were 21 and 5, respectively. The overall percentage agreement between histology and cytology was 69% and 84%, with a kappa (κ) of 0.36 and 0.08 at ≥1% and >50% cutoffs, respectively. The concordance between cytology and histology tended to be higher for epithelioid MM versus nonepithelioid MM at a ≥1% cutoff. PD-L1 positivity in biopsies, but not in effusions, correlated with the histologic subtype at a ≥1% cutoff.CONCLUSIONS: A moderate concordance of PD-L1 expression between biopsies and effusions from pleural MM, especially for the epithelioid subtype, indicates biological differences between the 2 types of specimens. Cytology and histology may be complementary.
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| 9. |
- Mansour, Mohammed S I, et al.
(författare)
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PD-L1 Testing in Cytological Non-Small Cell Lung Cancer Specimens : A Comparison with Biopsies and Review of the Literature
- 2021
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Ingår i: Acta Cytologica. - : S. Karger AG. - 0001-5547 .- 1938-2650. ; 65:6, s. 501-509
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Programmed death-ligand 1 (PD-L1) expression is used for treatment prediction in non-small cell lung cancer (NSCLC). While cytology may be the only available material in the routine clinical setting, testing in clinical trials has mainly been based on biopsies.METHODS: We included 2 retrospective cohorts of paired, concurrently sampled, cytological specimens and biopsies. Also, the literature on PD-L1 in paired cytological/histological samples was reviewed. Focus was on the cutoff levels ≥1 and ≥50% positive tumor cells.RESULTS: Using a 3-tier scale, PD-L1 was concordant in 40/47 (85%) and 66/97 (68%) of the paired NSCLC cases in the 2 cohorts, with kappa 0.77 and 0.49, respectively. In the former cohort, all discordant cases had lower score in cytology. In both cohorts, concordance was lower in samples from different sites (e.g., biopsy from primary tumor and cytology from pleural effusion). Based on 25 published studies including about 1,700 paired cytology/histology cases, the median (range) concordance was 81-85% (62-100%) at cutoff 1% for a positive PD-L1 staining and 89% (67-100%) at cutoff 50%.CONCLUSIONS: The overall concordance of PD-L1 between cytology and biopsies is rather good but with significant variation between laboratories, which calls for local quality assurance.
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| 10. |
- Mansour, Mohammed S.I., et al.
(författare)
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PD‐L1 Expression in Non‐Small Cell Lung Cancer Specimens : Association with Clinicopathological Factors and Molecular Alterations
- 2022
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 23:9
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Tidskriftsartikel (refereegranskat)abstract
- Immune checkpoint inhibitors (ICI) targeting programmed cell death‐1 or its ligand (PD‐ L1) have improved outcomes in non‐small cell lung cancer (NSCLC). High tumor PD‐L1 expression, detected by immunohistochemistry (IHC) typically on formalin‐fixed paraffin‐embedded (FFPE) histological specimens, is linked to better response. Following our previous investigation on PD‐L1 in cytological samples, the aim of this study was to further explore the potential impacts of various clinicopathological and molecular factors on PD‐L1 expression. Two retrospective NSCLC cohorts of 1131 and 651 specimens, respectively, were investigated for PD‐L1 expression (<1%/1– 49%/≥50%), sample type, sample site, histological type, and oncogenic driver status. In both cohorts, PD‐L1 was positive (≥1%) in 55% of the cases. Adenocarcinomas exhibited lower PD‐L1 expression than squamous cell carcinomas (p < 0.0001), while there was no difference between sample types, tumor locations, or between the two cohorts in multivariate analysis (all p ≥ 0.28). Mutational status correlated significantly with PD‐L1 expression (p < 0.0001), with the highest expression for KRASmutated cases, the lowest for EGFR‐mutated, and the KRAS/EGFR wild‐type cases in between. There was no difference in PD‐L1 levels between different prevalent KRAS mutations (all p ≥ 0.44), while mucinous KRAS‐mutated adenocarcinomas exhibited much lower PD‐L1 expression than non‐mucinous (p < 0.0001). Our data indicate that cytological and histological specimens are comparable for PD‐L1 evaluation. Given the impact of KRAS mutations and the mucinous growth pattern on PD‐L1 expression, these factors should be further investigated in studies on ICI response.
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