| 1. |
- Garvin, Stina, 1977-
(författare)
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Effects of sex steroids and tamoxifen on VEGF in the breast
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sex steroid exposure constitutes a risk factor for breast cancer, but little is known about the effects of sex steroids on factors mediating angiogenesis, the development of new blood vessels, in normal and malignant breast tissue. In this thesis we have investigated the effects of estradiol, progesterone, and the nonsteroidal anti-estrogen tamoxifen on vascular endothelial growth factor (VEGF) and its receptors (VEGFR-1 and VEGFR-2) in normal human breast tissue, endothelial cells, and breast cancer. We have applied the technique of microdialysis to provide in situ sampling of estradiol and VEGF in tumors and normal breast tissue of breast cancer patients in vivo. Furthermore, we present a novel method of culturing normal human breast tissue ex vivo.Our results suggest a pro-angiogenic effect of estradiol and an anti-angiogenic effect of tamoxifen in the breast. Estradiol increased extracellular levels of VEGF in normal human breast tissue and breast cancer cells in vitro. In addition, estradiol decreased sVEGFR-1 in breast cancer cells and indirectly increased VEGFR-2 in endothelial cells. Compared to estradiol treatment alone, estradiol + tamoxifen increased sVEGFR-1 and decreased VEGF in breast cancer cells in vitro. Furthermore, estradiol + tamoxifen decreased tumor VEGF levels and tumor vasculature in human breast cancer xenografts in vivo. In breast cancer patients, a significant correlation was found between in vivo levels of estradiol and VEGF sampled by microdialysis in normal human breast tissue, suggesting that estradiol may be a potent regulator of VEGF in the breast in vivo. Tumor levels of VEGF were significantly higher than in normal breast tissue in vivo, supporting the role of VEGF in tumor angiogenesis. For studies of normal human breast, whole breast tissue may be cultured in vitro for up to one week with preserved morphology. Using this method, estradiol, and not progesterone, appears to be the main sex steroid regulator of extracellular VEGF in normal breast tissue. In conclusion, the data suggest that sex steroids and tamoxifen exert pro- and anti-angiogenic effects in normal breast tissue and breast cancer.
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| 2. |
- Garvin, Stina, 1977-, et al.
(författare)
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Resveratrol induces apoptosis and inhibits angiogenesis in human breast cancer xenografts in vivo
- 2006
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Ingår i: Cancer Letters. - : Elsevier BV. - 0304-3835 .- 1872-7980. ; 231:1, s. 113-122
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Tidskriftsartikel (refereegranskat)abstract
- Resveratrol, a polyphenol found in grapes and wine, is considered a potential cancer chemopreventive agent. Resveratrol has been shown to induce transcription via both ERα and ERβ. We observed significantly lower tumor growth, decreased angiogenesis, and increased apoptotic index in ERα- ERβ+ MDA-MB-231 tumors in resveratrol-treated nude mice compared with controls. In vitro we found a significant increase in apoptosis in resveratrol-treated MDA-MB-231 cells in addition to significantly reduced extracellular levels of VEGF. This study supports the potential use of resveratrol as a chemotherapeutic agent in breast cancers. © 2005 Elsevier Ireland Ltd. All rights reserved.
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| 3. |
- Garvin, Stina, 1977-, et al.
(författare)
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Tumor cell expression of CD163 is associated to postoperative radiotherapy and poor prognosis in patients with breast cancer treated with breast-conserving surgery
- 2018
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Ingår i: Journal of Cancer Research and Clinical Oncology. - : Springer. - 0171-5216 .- 1432-1335. ; 144:7, s. 1253-1263
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Tidskriftsartikel (refereegranskat)abstract
- Cancer cell fusion with macrophages results in highly tumorigenic hybrids that acquire genetic and phenotypic characteristics from both maternal cells. Macrophage traits, exemplified by CD163 expression, in tumor cells are associated with advanced stages and poor prognosis in breast cancer (BC). In vitro data suggest that cancer cells expressing CD163 acquire radioresistance. Tissue microarray was constructed from primary BC obtained from 83 patients treated with breast-conserving surgery, 50% having received postoperative radiotherapy (RT) and none of the patients had lymph node or distant metastasis. Immunostaining of CD163 in cancer cells and macrophage infiltration (MI) in tumor stroma were evaluated. Macrophage:MCF-7 hybrids were generated by spontaneous in vitro cell fusion. After irradiation (0, 2.5 and 5 Gy gamma-radiation), both hybrids and their maternal MCF-7 cells were examined by clonogenic survival. CD163-expression by cancer cells was significantly associated with MI and clinicopathological data. Patients with CD163-positive tumors had significantly shorter disease-free survival (DFS) after RT. In vitro generated macrophage:MCF-7 hybrids developed radioresistance and exhibited better survival and colony forming ability after radiation compared to maternal MCF-7 cancer cells. Our results suggest that macrophage phenotype in tumor cells results in radioresistance in breast cancer and shorter DFS after radiotherapy.
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| 4. |
- Jedlinski, Adam, 1978-, et al.
(författare)
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Cetuximab sensitivity of head and neck squamous cell carcinoma xenografts is associated with treatment-induced reduction in EGFR, pEGFR, and pSrc.
- 2017
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Ingår i: Journal of Oral Pathology & Medicine. - : Wiley. - 0904-2512 .- 1600-0714. ; 46:9, s. 717-724
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aims of this study were to validate in vitro drug sensitivity testing of head and neck squamous cell carcinoma (HNSCC) cell lines in an in vivo xenograft model and to identify treatment-induced changes in the epidermal growth factor receptor (EGFR) signaling pathway that could be used as markers for cetuximab treatment response.MATERIALS AND METHODS: The in vitro and in vivo cetuximab sensitivity of two HNSCC cell lines, UT-SCC-14 and UT-SCC-45, was assessed using a crystal violet assay and xenografts in nude mice, respectively. The expression of EGFR, phosphorylated EGFR (pEGFR), phosphorylated Src (pSrc), and Ki-67 was investigated by immunohistochemistry. To verify these results, the in vitro expression of EGFR and pEGFR was analyzed with ELISA in a panel of 10 HNSCC cell lines.RESULTS: A close correlation was found between in vitro and in vivo cetuximab sensitivity data in the two investigated HNSCC cell lines. In treatment sensitive UT-SCC-14 xenografts, there was a decrease in EGFR, pEGFR, and pSrc upon cetuximab treatment. Interestingly, in insensitive UT-SCC-45 xenografts, an increased expression of these three proteins was found. The change in EGFR and pEGFR expression in vivo was confirmed in cetuximab-sensitive and cetuximab-insensitive HNSCC cell lines using ELISA.CONCLUSION: High sensitivity to cetuximab was strongly associated with a treatment-induced reduction in pEGFR both in vivo and in vitro in a panel of HNSCC cell lines, suggesting that EGFR and pEGFR dynamics could be used as a predictive biomarker for cetuximab treatment response.
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| 5. |
- Lindström, Annelie, et al.
(författare)
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Fusion between M2-macrophages and cancer cells results in a subpopulation of radioresistant cells with enhanced DNA-repair capacity
- 2017
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Ingår i: Oncotarget. - : IMPACT JOURNALS LLC. - 1949-2553. ; 8:31, s. 51370-51386
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Tidskriftsartikel (refereegranskat)abstract
- Cell fusion is a natural biological process in normal development and tissue regeneration. Fusion between cancer cells and macrophages results in hybrids that acquire genetic and phenotypic characteristics from both maternal cells. There is a growing body of in vitro and in vivo data indicating that this process also occurs in solid tumors and may play a significant role in tumor progression. However, investigations of the response of macrophage: cancer cell hybrids to radiotherapy have been lacking. In this study, macrophage: MCF-7 hybrids were generated by spontaneous in vitro cell fusion. After irradiation, both hybrids and their maternal MCF-7 cells were treated with 0 Gy, 2.5 Gy and 5 Gy.-radiation and examined by clonogenic survival and comet assays at three time points (0 h, 24 h, and 48 h). Compared to maternal MCF-7 cells, the hybrids showed increased survival fraction and plating efficiency (colony formation ability) after radiation. The hybrids developed less DNA-damage, expressed significantly lower residual DNA-damage, and after higher radiation dose showed less heterogeneity in DNA-damage compared to their maternal MCF-7 cells. To our knowledge this is the first study that demonstrates that macrophage: cancer cell fusion generates a subpopulation of radioresistant cells with enhanced DNA-repair capacity. These findings provide new insight into how the cell fusion process may contribute to clonal expansion and tumor heterogeneity. Furthermore, our results provide support for cell fusion as a mechanism behind the development of radioresistance and tumor recurrence.
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| 6. |
- Pocevičiūtė, Milda, 1992-, et al.
(författare)
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Detecting Domain Shift in Multiple Instance Learning for Digital Pathology Using Fréchet Domain Distance
- 2023
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Ingår i: Medical Image Computing and Computer Assisted Intervention – MICCAI 2023. - : Springer. - 9783031439032 - 9783031439049 ; , s. 157-167
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Konferensbidrag (refereegranskat)abstract
- Multiple-instance learning (MIL) is an attractive approach for digital pathology applications as it reduces the costs related to data collection and labelling. However, it is not clear how sensitive MIL is to clinically realistic domain shifts, i.e., differences in data distribution that could negatively affect performance, and if already existing metrics for detecting domain shifts work well with these algorithms. We trained an attention-based MIL algorithm to classify whether a whole-slide image of a lymph node contains breast tumour metastases. The algorithm was evaluated on data from a hospital in a different country and various subsets of this data that correspond to different levels of domain shift. Our contributions include showing that MIL for digital pathology is affected by clinically realistic differences in data, evaluating which features from a MIL model are most suitable for detecting changes in performance, and proposing an unsupervised metric named Fréchet Domain Distance (FDD) for quantification of domain shifts. Shift measure performance was evaluated through the mean Pearson correlation to change in classification performance, where FDD achieved 0.70 on 10-fold cross-validation models. The baselines included Deep ensemble, Difference of Confidence, and Representation shift which resulted in 0.45, -0.29, and 0.56 mean Pearson correlation, respectively. FDD could be a valuable tool for care providers and vendors who need to verify if a MIL system is likely to perform reliably when implemented at a new site, without requiring any additional annotations from pathologists.
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| 7. |
- Pocevičiūtė, Milda, 1992-
(författare)
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Generalisation and reliability of deep learning for digital pathology in a clinical setting
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Deep learning (DL) is a subfield of artificial intelligence (AI) focused on developing algorithms that learn from data to perform some tasks that can aid humans in their daily life or work assignments. Research demonstrates the potential of DL in supporting pathologists with routine tasks like detecting breast cancer metastases and grading prostate cancer. However, a widespread adoption of DL technology in pathology labs has been slow for several reasons. DL models often exhibit performance variations across medical centres, patient subgroups, and even within the same centre over time. While collecting more data and retraining the algorithms seems like a straightforward solution, it is a costly and time-consuming process. Moreover, retraining DL systems with regulatory approvals is complex due to existing regulations. Another limitation of DL models is their inability to provide confidence estimates for predictions, leaving users in the dark about their reliability. Finally, establishing a close collaboration between the research community, vendors, and pathology labs is crucial for producing effective DL systems for patient care. However, this collaboration faces challenges like miscommunication, misalignment of goals, and misunderstanding priorities.This thesis presents various approaches that could tackle the generalisation and reliability challenges faced by diagnostic DL systems for digital pathology with a strong emphasis on the clinical needs. To address the generalisation issues, an unsupervised approach to quantify expected changes in a model’s performance between two datasets is proposed. This approach can serve as an initial validation step before deploying diagnostic DL systems in clinical practice, reducing annotation costs. Additionally, an unsupervised framework based on generative models is proposed to identify substantially different inputs, known as out-of-distribution (OOD) samples. Detecting OOD samples plays a crucial role in enhancing the reliability of DL algorithms. Furthermore, several studies are conducted to explore what benefits uncertainty estimation could bring. Firstly, various uncertainty estimation approaches are extensively evaluated, focusing on identifying incorrect predictions and generalisability issues between medical centres and specific patient groups. In addition, the results reveal that combining uncertainty estimation methods with DL outputs leads to a more robust classification score, enhancing the overall performance and reliability of the classification process. Another study demonstrates that spatial uncertainty aggregation improves the effectiveness of uncertainty estimation in tumour segmentation tasks. This is evaluated on the detection of false negatives which may reduce the risk of missing tumour cells. Finally, the clinical prerequisites for developing and validating diagnostic DL systems for digital pathology are discussed, along with an overview of explainable AI techniques.In conclusion, multiple approaches to facilitate the adoption of DL systems in clinical practice, addressing reliability, generalisability, and clinical needs aspects are discussed in this thesis. I believe that the extensive efforts in the research community will have a positive impact on the development, validation, and deployment of DL systems in digital pathology labs, empowering pathologists with trustworthy AI tools.
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| 8. |
- Tiefenböck-Hansson, Katharina, 1982-
(författare)
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The impact of Survivin, WRAP53β, and Hypoxia on treatment response in Head and Neck Cancer
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Squamous cell carcinoma (SCC) is the most common histological type of cancer in the head and neck region and arises in the epithelial mucosa of the upper aerodigestive tract. Approximately one and a half million people are living with the diagnosis. Despite efforts in prevention and advances in treatment, the 5-year survival rate still lies around 60%, and recurrences and second primary tumors remain a problem. Moreover, treatment responses vary from patient to patient, highlighting the need for individually tailored treatments. To make this possible, biomarkers predicting treatment outcome are needed to better guide treatment decisions.The aim of this thesis was to evaluate the expression of certain proteins and the frequency of certain SNPs (Single nucleotide polymorphisms) in tumor biopsies and cell cultures of head and neck squamous cell carcinomas (HNSCC), and to explore their potential as biomarkers for treatment outcome. Furthermore, we aimed to study the impact of hypoxia on treatment response, epithelial-tomesenchymal transition (EMT), and induction of cancer stem cells (CSC).In papers I and II, we investigated two proteins, survivin and WRAP53β, using immunohistochemistry (IHC) in tumor biopsies from 40 patients categorized as Non-responders or Responders to radiotherapy. High expression of survivin and nuclear expression of WRAP53β were significantly more prevalent in the Responder group. The combination of these two factors correlated strongest to overall survival, but not to a significantly higher extent compared to survivin alone. Moreover, when examined separately, a high percentage of p53-stained cells and the presence of the SNP FGFR4 Gln388Arg correlated to improved overall survival, whereas the SNP XPD Lys751Gln was associated with worse overall survival. The latter three showed no significant correlations to radiotherapy response. In paper III, the two most promising proteins identified in papers I and II were analyzed in a study cohort of 149 tumor biopsies of glottic laryngeal SCC, categorized as T2N0-T3N0. In this patient group, no significant associations between survivin expression and survival could be found. However, expression of cytoplasmic WRAP53β was significantly linked to worse disease-free-survival (DSF) compared to nuclear WRAP53β or negative staining for WRAP53β. Positive expression of p16INK4a was found in 7% of the tumors. The prevalence of p16 INK4a was higher in younger patients (<60) and associated with absence of recurrence and longer DSF.In paper IV, five HNSCC cell lines were cultured in normoxic (20% O2) and hypoxic (1% O2) conditions and changes in treatment response, EMT profile, and expression of CSC markers were examined. As expected, hypoxia induced EMT and to a certain extent expression of CSC markers. Silencing of the hypoxia-inducible-factor-1α (HIF-1α) only partly reversed these effects, suggesting that other mechanisms are involved. Whereas most cell lines became more resistant to treatment in hypoxia, one cell line (LK0412) became more sensitive to cetuximab-treatment in hypoxia, an effect that was revoked by depletion of HIF-1α, suggesting a possible sensitizing effect of HIF-1α to cetuximab-treatment.Taken together, WRAP53β appears to be a promising biomarker candidate for treatment outcome in HNSCC, but further evaluation especially on the subcellular localization of WRAP53β is required. Even though the role of survivin in radiotherapy response in glottic SCC seems to be insignificant, it might have a more important role in other HNSCC subsites. As far as the effects of hypoxia, it appears that hypoxia might have a sensitizing effect on cetuximab-treatment in certain cases, which seems to be HIF1-α –dependent. Further studies are required to clarify the importance of this observation.
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| 9. |
- Tiefenböck Hansson, Katharina, et al.
(författare)
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WRAP53 beta, survivin and p16(INK4a) expression as potential predictors of radiotherapy/chemoradiotherapy response in T2N0-T3N0 glottic laryngeal cancer
- 2017
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Ingår i: Oncology Reports. - : SPANDIDOS PUBL LTD. - 1021-335X .- 1791-2431. ; 38:4, s. 2062-2068
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Tidskriftsartikel (refereegranskat)abstract
- The current treatment recommendation for T2-3N0M0 glottic squamous cell carcinoma (SCC) in the Nordic countries comprises of radiotherapy (RT) and chemoradiotherapy (CRT). Tumor radiosensitivity varies and another option is primary surgical treatment, which underlines the need for predictive markers in this patient population. The aim of the present study was to investigate the relation of the proteins WRAP53 beta, survivin and p16INK4a to RT/CRT response and ultimate outcome of patients with T2-T3N0 glottic SCC. Protein expression was determined using immunohistochemistry on tumors from 149 patients consecutively treated with RT or CRT at Helsinki University Hospital, Karolinska University Hospital, and Linkping University Hospital during 1999-2010. Our results demonstrate a significantly better 5-year relapse-free survival, disease-free survival (DFS), disease-specific survival and overall survival of patients with T3N0 tumors treated with CRT compared with RT alone. Patients with tumors showing a cytoplasmic staining of WRAP53 beta revealed significantly worse DFS compared with those with nuclear staining. For survivin, we observed a trend towards better 5-year DFS in patients with strong nuclear survivin expression compared with those with weak nuclear survivin expression (p=0.091). Eleven (7%) tumors showed p16 positivity, with predilection to younger patients, and this age group of patients with p16-positive SCC had a significantly better DFS compared with patients with p16-negative SCC. Taken together, our results highlight WRAP53 beta as a potential biomarker for predicting RT/CRT response in T2-T3N0 glottic SCC. p16 may identify a small but distinct group of glottic SCC with favorable outcome. Furthermore, for T3N0 patients better outcome was observed following CRT compared to RT alone.
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