| 1. |
- Lidgren, Anders, 1975-
(författare)
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Hypoxia inducible factor-1α in renal cell carcinoma
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hypoxia Inducible Factor-1α in Renal Cell Carcinoma Departments of Surgical and Perioperative Sciences, Urology and Andrology; Radiation Sciences, Oncology; Medical Biosciences, Pathology; and Medical Biosciences, Clinical Chemistry, Umeå University, Umeå, Sweden Background: Renal cell carcinoma (RCC) accounts for approximately 2-3% of all human cancers. A distinguished feature of RCC is vascularisation and among the three dominating RCC types conventional RCC (cRCC) generally is more vascularised than papillary RCC (pRCC) and chromophobe RCC (chRCC). Angiogenesis is a critical step in tumour progression controlled by a balance involving molecules that have positive and negative regulatory activity. A balance distorted by metabolic stress such as hypoxia, acidosis, and inflammation. Hypoxia-Inducible Factor 1α (HIF-1α) is a key transcription factor in angiogenesis and tumour progression, targeting more than a 100 genes involved in vascular growth and regulation, iron metabolism and erythropoesis, collagen matrix formation, regulation of extracellular pH, glucose uptake and metabolism, proliferation, apoptosis, differentiation, and cell viability. Methods: Tumour tissue and corresponding kidney cortex from nephrectomised RCC patients was used in order to characterize HIF-1α expression and one of its target genes, Glucose Transporter 1 (GLUT-1). All tumour samples were thoroughly described regarding tumour type, TNM stage, nuclear grade, tumour size, vein invasion, and patient survival. Utilizing RT-PCR, Westen Blot and Tissue micro array (TMA) we studied HIF-1α mRNA and protein expression as well as GLUT-1 protein expression, correlating them to each other and clinicopathological parameters. Results: Using Western Blot, HIF-1α protein expression differed significantly between the different RCC types and kidney cortex. In cRCC, high expression of HIF-1α was an independent prognostic factor for favourable prognosis. TMA is a useful method to analyze HIF-1α protein expression in RCC. HIF-1α levels were significantly lower in locally aggressive cRCC and patients with high levels of HIF-1 tended to have a better prognosis. GLUT-1 levels were higher in cRCC than in other RCC types and for cRCC a correlation to HIF-1α was seen. HIF-1α mRNA levels were significantly lower in cRCC compared to other RCC types and kidney cortex. An inverse correlation between HIF-1α protein expression and mRNA levels was observed. Summary: These results demonstrate a discrepancy between RCC types, highlighting the need to separately evaluate biological events in different RCC types. Overexpression of HIF-1α protein is not necessarily all bad and translational regulation appears more critical than anticipated. Further studies are encouraged to clarify angiogenic pathways in RCC.
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| 2. |
- Crnalic, Sead, 1960-
(författare)
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Metastatic spinal cord compression in prostate cancer : clinical and morphological studies
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Bone metastases occur in most patients with advanced hormone-refractory prostate cancer causing pain, pathologic fractures, and spinal cord compression. Few studies specifically address surgical treatment of metastatic spinal cord compression (MSCC) in prostate cancer. Criteria for identifying patients who may benefit from surgery are poorly defined. Most of the current knowledge regarding tumor biology in prostate cancer is based on studies of primary tumors or soft tissue metastases. The mechanisms regulating growth of bone metastases are not fully established. Aims: a) to evaluate outcome after surgery for MSCC in prostate cancer and to identify prognostic factors for survival and functional recovery; b) to evaluate current practice for referral of prostate cancer patients with MSCC; c) to analyze expression of androgen receptor (AR), cell proliferation, apoptosis, and prostate-specific antigen (PSA) in bone metastases with regard to survival after surgery for complications of bone metastases. Patients and Methods: We retrospectively evaluated the hospital records of 68 consecutive patients operated for metastatic spinal cord compression. Tumor tissue from bone metastases was obtained on spinal surgery (54 patients), fracture surgery (4 patients) and biopsy (2 patients), and analyzed by immunohistochemistry. Results: Study I: Mortality and complication rate after surgery was high. Patients with hormone-naïve disease and those with hormone-refractory disease with good performance status and without visceral metastases had more favorable survival. The ability to walk after surgery was related to better survival. Study II: A new score for prognosis of survival after surgery for spinal cord compression includes: hormone status of prostate cancer, Karnofsky performance status, evidence of visceral metastasis, and preoperative serum PSA. The score is simple, tumor specific, and easy to apply in clinical practice. Study III: Our results suggest that delays in diagnosis and treatment may have negative impact on functional outcome. Pretreatment ability to walk, hormone status of prostate cancer, and time from loss of ambulation influenced neurological recovery after surgery for spinal cord compression. Study IV: High nuclear AR immunostaining in bone metastases and high preoperative serum PSA were associated with a poor outcome after metastasis surgery in patients with hormone-refractory prostate cancer. Short-term effect of castration therapy disclosed that nuclear AR immunostaining was decreased and apoptosis was increased, but cell proliferation remained largely unaffected. Conclusion: Prostate cancer patients with metastatic spinal cord compression represent a heterogeneous group. We identified prognostic factors for survival and functional outcome, which may help clinicians in making decisions about treatment. Our results also implicate the need for development of local and regional guidelines for treatment of patients with spinal cord compression, as well as the importance of information to patients at risk.
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| 3. |
- Jacobsen, Jan, 1957-
(författare)
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Vascular endothelial growth factor in renal cell carcinoma
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background. Angiogenesis is essential for tumour growth. Vascular endothelial growth factor (VEGF) and its isoforms were investigated in relation to the clinical course in a large number of patients with renal cell carcinoma (RCC). Methods. RCC subtypes and behaviour were established by clinicopathological criteria and surveillance. VEGF expression was analysed in serum by enzyme-linked immuno-sorbent assay (ELISA) and in tumour tissue by reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and Western blot (WB). Results. Serum VEGF (S-VEGF) was increased in RCC compared to control group. S-VEGF correlated with tumour stage and grade and was associated with survival in men but not in women. S-VEGF correlated with blood platelet counts, which were inversely correlated to increasing age in women, and they were decreased in chronically medicated patients, particularly in men. In contrast to S-VEGF, platelet counts associated with survival only in patients free of medication and chronic diseases. RT-PCR showed a correlation between VEGF121/VEGF165 mRNA and between VEGF165/VEGF-R1 mRNA. There was no association between different VEGF mRNA isoforms and S-VEGF. Conventional renal cell carcinoma (CRCC) had higher VEGF165, VEGF121, and VEGF-R1 mRNA levels compared with papillary renal cell carcinoma (PRCC). IHC VEGF staining was strong in kidney cortex. Kidney tumour showed a considerable variation in cytoplasmatic VEGF expression, which correlated with tumour size. Although, there was no difference in VEGF expression between the RCC types, VEGF expression was associated with survival only in CRCC. WB showed a strong protein expression of both VEGF189 and VEGF165 in kidney cortex. In kidney tumour, expression of VEGF189 varied the most, VEGF165 less so, and VEGF121 was rarely detected. Both CRCC and PRCC expressed low levels of VEGF189 and VEGF165 compared with kidney cortex. Chromophobe renal cell carcinoma (ChRCC) expressed VEGF189 levels comparable to those from kidney cortex, while VEGF165 was lower. In PRCC and ChRCC, VEGF189 levels correlated inversely with advancing tumour stage, and in PRCC, VEGF165 levels correlated inversely with increasing tumour size. VEGF189 was an independent prognostic factor for survival in patients with PRCC. Conclusions. S-VEGF has a stronger association to progression in RCC than platelet count. CRCC showed high levels of VEGF mRNA isoforms and VEGF-R1 mRNA compared to PRCC. VEGF mRNA isoforms expression decreased with advancing stage. IHC demonstrated VEGF expression in cell cytoplasm related to tumour growth, particular in CRCC. Different VEGF isoform patterns were found in different RCC types. Protein VEGF189 expression was associated with tumour stage and was an independent prognostic factor in PRCC. Protein VEGF165 expression was generally low and had no prognostic value. The trend for decreasing levels of VEGF isoforms in advanced tumour stages may indicate that angiogenic activity is an early event in tumour growth induced by VEGF, but that during later tumour progression the role of VEGF is less clear.
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| 4. |
- Järemo, Helena, 1988-
(författare)
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MicroRNA expression profiles in prostate cancer bone metastases : functional effects of microRNA-23c, -375, and -4328
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Non-coding microRNAs (miRNAs) function as post-transcriptional regulators of gene expression by interacting with messenger RNA. Dysregulation of miRNAs has many possible consequences, including tumor-suppressive or -promoting ones, and restoring or preventing the effects of miRNA alteration has therapeutic potential.Metastatic prostate cancer (PC) spreads to the bone and is treated with castration therapy. Eventually, metastases relapse into castration-resistant PC (CRPC) growth. Recently, our laboratory described metastatic PC subtypes, termed MetA-C, defined based on transcriptomic differences and linked to different morphology and prognosis. Patients with MetB metastases have particularly poor prognosis.The overall aim of the thesis was to identify novel biomarkers and therapeutic targets for metastatic PC, with a focus on miRNAs. The specific aims were to: (1) identify miRNAs associated with PC progression into bone metastasis, and their functional roles; (2) verify the MetA-C subtypes, their prognostic importance, and their relation to genetic profiles in independent validation cohorts; (3) explore miRNA expression profiles of PC bone metastases, specifically in relation to the MetA-C subtypes, and whether specific miRNAs show potential to inhibit the aggressive MetB subtype.Study 1: Differentially expressed miRNAs (n=79) were identified by microarray analysis by comparing miRNA levels in bone metastatic (n=14) or localized PC (n=7) samples to benign samples (n=7). Downregulation of miRNA-23c and -4328 was verified by qRT-PCR analysis, including a larger cohort of bone metastases (n=67). Overexpression of miRNA-23c or -4328 in PC cells resulted in attenuated cell growth in vitro. High levels of miRNA-23c were detected in extracellular vesicles shed from overexpressing cells. Overexpression of miRNA-23c did not obviously affect tumor growth or angiogenesis in vivo. Study 2: The existence and prognostic value of the MetA-C subtypes was verified by transcriptomic analysis of bone metastasis samples (n=103), and by subtyping publicly available data from metastatic samples (n=573) from external patient cohorts. The MetB subtype was associated with high tumor-cell proliferation, low androgen receptor activity, and poor prognosis in all cohorts, and provided independent prognostic information in addition to genetic aberrations.Study 3: The miRNA profiles of 96 bone metastasis samples from Study 2 were examined using microarray analysis. Four sample clusters not obviously related to the MetA-C subtypes were observed. Expression levels of miRNA-375, however, were inversely related to MetB. MiRNA-375 overexpression in C4-2B resulted in a cellular switch of subtype, from being dominant MetB to dominant MetA. In parallel, reduced cell growth and signs of increased cell adhesion were observed.In conclusion, altered miRNA profiles may contribute to progression of PC into bone metastasis, and to the development of different metastasis subtypes. The MetB subtype is associated with poor prognosis and low expression of miRNA-375. Therapy stratification based on the MetA-C subtypes should be considered in the future. Restoration of miRNA-375 in MetB tumors may offer a novel treatment option.
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| 5. |
- Josefsson, Andreas, 1979-
(författare)
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Prognostic markers in prostate cancer : studies of a watchful waiting cohort with long follow up
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Prostate Cancer (PC) is a common and highly variable disease. Using current diagnostic methods, the prostate specific antigen (PSA) blood test and histological grading of prostate tissue needle biopsies, it is often difficult to evaluate whether the patient has a PC that requires active treatment or not. The absolute majority of all 10,000 cases of PCs diagnosed annually in Sweden have tumours graded as Gleason score (GS) 6-7 and a PSA value in blood below 10. Many of these are harmless and can be left without active treatment and hence spared problematic post-therapy side-effects, others are highly malignant and require early diagnosis and treatment. Better prognostic markers are needed and the aim of this study was to evaluate prognostic markers and to test if these markers could identify patients with indolent tumours. Methods: We have studied tumour material from 419 men consecutively diagnosed with PC at transurethral resection (1975-1990). The majority of these patients (295) had no metastasis at diagnosis and was not given any curative treatment and only hormonal treatment upon symptoms from metastatic progression. Standard histological sections and tissue microarrays (TMA) from these tumours and surrounding normal prostate tissue were stained and evaluated for cell proliferation (Ki67), blood vessels (endoglin and von Willebrand factor, vWf) and the extracellular matrix component hyaluronan (HA). An orthotopic rat PC model was used to explore hyaluronan staining, hyaluronic acid synthase (HAS)-1 mRNA levels and the effect of local HA treatment on tumour growth. Results: Tumour cell proliferation (Ki67) and the density of intra-tumoural endoglin stained blood vessels were independent prognostic markers (i.e. they added prognostic information to the conventional prognostic markers; clinical stage and GS). None of the GS 6 patients with low staining for both Ki67 and endoglin died of PC within 15 years of follow-up. High HA staining in the tumour epithelium and stroma was a negative prognostic marker of cancer specific survival but they were not independent of GS. High HA staining and high vascular density in the stroma of the surrounding morphologically normal prostate were prognostic for short cancer specific survival. Implantation of tumour cells in the normal rat prostate resulted in an increase in HA and HAS-1 mRNA levels in the prostate tissue surrounding prostate tumours. Concurrently intra-prostatic injection of HA also stimulated tumour growth. Conclusions: By evaluating both tumour cell proliferation (Ki67) and vascular density, it is possible to identify patients with very low risk of cancer specific death in the absence of active treatment. Prostate tumours influence the surrounding non-malignant prostate tissue, for example they cause an increased angiogenesis and synthesis of hyaluronan. Such responses can possibly be used to diagnose PC and to evaluate PC aggressiveness.
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| 6. |
- Sandlund, Johanna, 1979-
(författare)
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Angiogenesis in human renal cell carcinoma : hypoxia, vascularity and prognosis
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Angiogenesis is recognised as a critical step in tumour progression. The angiogenic switch is activated by various trigger signals, such as hypoxia, low pH, and genetic mutations. Renal cell carcinoma (RCC) is often an aggressive tumour, and advanced disease has limited treatment options and bad prognosis. This study was focused on markers of angiogenesis in RCC: endoglin (CD105) and CD31 assessing microvessel density (MVD), and carbonic anhydrase (CA) IX and hypoxia-inducible factor (HIF)-2α expressed at hypoxia. Upregulation of HIF is also associated with inactivation of the von Hippel-Lindau (VHL) tumour suppressor gene, which is common in conventional/clear cell (c)RCC. Method: A tumour bank containing 308 tumours from patients operated 1982-2003 was used. The tumours were well characterised regarding tumour type, TNM stage, nuclear grade, tumour size, and patient survival. The tumours were prepared in tissue microarrays and fresh frozen in whole sections. To analyse the expression of endoglin, CD31, CA IX, and HIF-2α mRNA, immunohistochemistry and real-time PCR were used. Results: There was a higher endoglin expression in cRCC than in papillary (p)RCC and chromophobe (ch)RCC, and a higher CD31 expression in cRCC than in pRCC. MVD correlated inversely to TNM stage and nuclear grade in cRCC. There was also an inverse correlation between tumour diameter and CD31 expression in cRCCs. Patients with cRCC with high MVD had a more favourable prognosis than patients with lower MVD. Endoglin and CD31 were not independent prognostic factors. The CA IX expression was higher in cRCC than in pRCC and chRCC. Patients with cRCC expressing low CA IX had a significantly less favourable prognosis compared with those with higher expression. CA IX is an independent prognostic factor. There was a higher HIF-2α mRNA expression in cRCC than in pRCC and chRCC. In cRCC, there was a significant inverse correlation between HIF-2α mRNA expression, and TNM stage and nuclear grade. There was also an inverse correlation between HIF-2α mRNA expression and tumour size among patients with cRCC. HIF-2α was not an independent prognostic factor. Conclusion: In these studies, the factors related to hypoxia and vascularity were all inversely correlated to tumour aggressiveness in cRCC. MVD, CA IX, and HIF-2α expression were also higher in cRCC than in pRCC and chRCC. The relationship between angiogenesis, vascularity, and hypoxia is ambiguous. A line of reasoning including mutations increasing angiogenesis in advanced disease may also be applied to RCC. Measurements of individual angiogenic factors seem to provide prognostic information, and can potentially be combined in patient monitoring and treatment.
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| 7. |
- Stenman, Katarina, 1963-
(författare)
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Prostate Cancer Diagnosis : experimental and Clinical Studies With HRMAS NMR Spectroscopy
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A few abnormal cells found in a small piece of prostate tissue are most consequential for a man’s future. The prevalence of prostate cancer (PCa) is increasing globally. The main instigating factor for this cancer is not yet known, but it appears to be the consequence of many variables such as an increasingly older population, more frequent PSA-testing, and factors involving lifestyle. Prostate cancer screening, as an equivalent for breast cancer screening, has been suggested but unfortunately there are no accurate diagnostic tools available for this type of screening. The reason for this is simply that the prostate is one of the most difficult organs to diagnose and, consequently, PCa screening would generate far too many false-positive and false-negative results. The prostate is not easily accessible as it is deeply-seated in the male pelvic area, wrapped around the urethra and surrounded by sensitive vital organs. Furthermore, PCa is frequently multi-focal, and the cancer cells have a tendency of assimilating among normal cells and, thus, do not always form solid lumps. Therefore, prostate tumors are often not felt by digital rectal examination (DRE) or identified by imaging. The PSA-test is not reliable as it is more prostate-specific than cancer-specific. Due to increasing prostate awareness, more early-stage and locally confined PCa are being detected. This is saving lives, although there is a high risk of over treatment and unnecessary side-effects. The increased detection of PCa requires sophisticated diagnostic methods and highly skilled clinicians who can discern between indolent and aggressive cancers. The current “gold-standard” for PCa diagnosis is biopsy grading by pathologists using the Gleason score system, which is a difficult task. Therefore, innovative methods to improve the precision of prostate diagnosis, by increased biopsy sensitivity and tumor localization, are of essence. In light of these difficulties, the metabolomic approach using 1D and 2D high-resolution magic angle spinning (HRMAS) NMR spectroscopy combined with histopathology on intact prostatectomy specimens was evaluated in this research project. The non-destructive nature of HRMAS NMR enables spectroscopic analysis of intact tissue samples with consecutive histological examinations under light microscope. Metabolomics aids in the unraveling and the discovery of organ-specific endogenous metabolites that have the potential to be reliable indicators of organ function and viability, extrinsic and intrinsic perturbations, as well as valuable markers for treatment response. The results may, therefore, be applied clinically to characterize an organ by utilizing biomarkers that have the capacity to distinguish between disease and health. The aim was to characterize the human and the rat prostate in terms of its intermediary metabolism, which I show here to differ between species and anatomical regions. Furthermore, the aim is to seek the verification of HRMAS NMR derived metabolites which are known to be a part of the prostate metabolome such as, citrate, choline, and the polyamines which were performed, but also the identification of metabolites not previously identified as part of the local prostate metabolism, such as Omega-6, which was detected in tumors. The extended aim was to elucidate novel bio-markers with clinical potential. In this study, the common phyto-nutrient, inositol, which appears to possess protective properties, was identified as being a potentially important PCa bio-marker for the distinction between the more indolent Gleason score 6 and the more aggressive Gleason score 7 in non-malignant prostate tissues with tumors elsewhere in the organ. Further studies in this area of PCa research are therefore warranted.
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| 8. |
- Wänman, Johan, 1983-
(författare)
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Clinical and morphological aspects of metastatic spinal cord compression
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Metastatic spinal cord compression (MSCC) is a serious complication of cancer leading to demyelination and axonal damage of the spinal cord with a risk of para/tetraplegia. It is most common in patients with known cancer but may also be the initial manifestation of malignancy (IMM). Patients with MSCC as the IMM have rarely been studied as a separate group. The interaction between the tumour and bone in spinal bone metastasis interferes with regulatory mechanisms, causing the formation of less mechanically competent bone and increasing the risk of spinal instability and fracture. The Spinal Instability Neoplastic Score (SINS) has been proposed as a tool in order to help clinicians evaluate tumour-related spinal instability. The SINS has shown excellent inter- and intraobserver reliability, but its prognostic value is still controversial. Bone metastases from prostate cancer are generally classified as osteoblastic due to increased bone formation. However, this categorization is probably oversimplified since there are overlapping bone cell activities between osteoblastic and osteolytic metastases. Prostate cancer bone metastases can also have a myeloma-like radiological appearance, but little is known about this subgroup of lesions. Aims: The aims of this work were as follows: a) to evaluate outcomes after surgery in patients with MSCC as the IMM; b) to analyse the prognostic value of the SINS regarding survival and neurological function after surgery for MSCC in patients with prostate cancer and haematological malignancies; and c) to analyse the clinical and morphological features of prostate cancer spinal bone metastases with a myeloma-like radiological appearance. Patients and methods: In studies I-III, we retrospectively evaluated the outcomes after surgery for MSCC in patients with MSCC as the IMM (study I, n=69), prostate cancer (study II, n=110) and haematological malignancies (study III, n=48). In study IV, tumour tissue samples from bone metastases obtained during surgery for MSCC in 110 patients with prostate cancer were analysed by immunohistochemistry and molecular transcriptomic analyses, and the results were related to the radiological appearance and clinical outcomes. Results: Study I: The primary tumour was identified in 59 of 69 patients. The median postoperative survival after surgery for MSCC was 20 months. Patients with prostate cancer had the longest median survival (6 years), and patients who were defined as having cancer of unknown primary tumour had the shortest median survival (3.5 months). Surgery maintained and improved the ability to walk in these patients. Study II: A total of 106 of 110 patients met the SINS criteria for potential instability or instability. There was no statistically significant difference in the overall risk of death between the SINS potentially unstable and unstable SINS categories, or in the risk of loss of ambulation one month after surgery. Study III: The median postoperative survival was 71.5 months in patients with myeloma and 58.7 months in patients with lymphoma. The SINS was not related to postoperative survival or neurological outcomes. The ability to walk before surgery was strongly associated with the postoperative ambulatory status. On multivariate Cox regression analysis, the ability to walk and a higher blood haemoglobin level prior to surgery were associated with superior survival. Study IV: A myeloma-like radiological appearance of prostate cancer spinal bone metastases was associated with poor survival and neurological outcomes after surgery for MSCC. Conclusions: Patients with MSCC as the IMM resemble a heterogeneous group in which survival is highly dependent on the type of primary tumour. A diagnostic workup is essential before a prognosis can be estimated in order to select candidates for surgery. The SINS may be helpful in selecting patients for surgery for MSCC, but it cannot be used to predict postoperative survival or neurological outcomes in patients with prostate cancer or in patients with haematological malignancies. A myeloma-like radiological appearance of prostate cancer spinal bone metastases is a strong negative predictor for survival and neurological outcomes after surgery for MSCC.
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| 9. |
- Bergh, Ann-Charlotte, 1980-
(författare)
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Importance of microenvironment and antigen in the regulation of growth and survival of CLL cells
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chronic lymphocytic leukemia (CLL) cells rapidly die when put in culture implying that microenvironmental signals delivered by accessory cells confer CLL cells with a growth advantage. Recent findings show that CLL cells are antigen experienced and antigen binding play a critical role in the pathogenesis of the disease. The overall aim of this thesis was to study the influence of the microenvironment and antigen binding in CLL.In paper I, we studied the influence of the small redox-regulatory molecule thioredoxin (Trx) on CLL cell survival and proliferation. We found Trx to be highly expressed in CLL lymph nodes (LNs), secreted from stromal cells surrounding proliferating CLL cells in proliferation centers, indicating growth promoting properties. Secreted Trx was also shown to protect CLL cells from apoptosis.In paper II, oxidized LDL was added to subset #1 CLL cells. However, in contrast to our hypothesis, we could not observe activation and proliferation of CLL cells. Instead subset #1 CLL cells were unresponsive/anergic through the B cell receptor (BcR). This anergic state could however be overcome by “wash out” of bound antigen or addition of toll-like receptor 9 stimulation in some patients.Gene expression profiles differ between groups of CLL patients and in peripheral blood (PB) and LN compartment, due to different microenvironments. However, it is not known whether these differences also apply for DNA methylation. In paper III, we identified various genes that were alternatively methylated between IGHV mutated (M) and unmutated (UM) groups. For example prognostic genes, CLLU1 and LPL, genes involved in B cell signaling, IBTK, as well as numerous TGF-β and NF-κB/TNF pathway genes.The intensity and duration of BcR signals are fine-tuned by enhancing or inhibitory coreceptors. SHP-1 inhibits BcR-signals by dephosphorylation. In paper IV, we compared the expression and activity of SHP-1 in CLL cells from LN with matched PB samples. However, in contrast to our hypothesis, SHP-1 activity/phosphorylation status in PB and LN, did not differ significantly.This thesis, add another piece to the puzzle, on how the microenvironment and antigens influence CLL pathogenesis. Since great variations among individuals are seen, further studies in different groups of patients are necessary to elucidate the importance of antigen for the development of CLL.
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| 10. |
- Bovinder Ylitalo, Erik, 1985-
(författare)
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Molecular heterogeneity of prostate cancer bone metastasis
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Castration-resistant prostate cancer (CRPC) develops after androgen deprivation therapy of advanced PC, often with metastatic growth in bone. Patients with metastatic CRPC have very poor prognosis. Growth of CRPC, in most but not all patients, seems to involve androgen receptor (AR) activity, despite castrate levels of serum testosterone. Multiple mechanisms behind AR activation in castrated patients have been described, such as AR amplification, AR mutations, expression of constitutively active AR variants, and intra-tumoral steroid synthesis. However, other mechanisms beside AR activation are also involved and CRPC patients with tumors circumventing the need for AR stimulation will probably not benefit from AR targeting therapies but will need alternative treatments.Available treatments for CRPC are chemotherapy, AR antagonists or inhibition of androgen-synthesis. Novel drugs are constantly under development and several new therapies has recently been approved for clinical use. These include, in addition to new AR targeting therapies also immunotherapy, osteoclast inhibitors and bone-targeting radiopharmaceuticals. Due to heterogeneous mechanisms behind CRPC and that newly developed therapies are based on different mechanisms of action, there are reasons to believe that CRPC patients show different therapy responses due to diverse molecular properties of individual tumors. Although there are promising prospects, no biomarkers are used today for patient stratification into different treatments. Another important aspect is that, when effective, any therapy will probably induce tumor responses that subsequently cause further molecular diversities and alternative paths for development of tumor relapse and castration-resistance. Such mechanisms are important to understand in order to develop new treatment strategies.In this thesis, global gene expression and methylation patterns were studied in bone metastases obtained from PC patients going through metastasis surgery for spinal cord compression. Gene expression patterns were analyzed by multivariate statistics and ontology analysis with the aim to identify subgroups of biological/pathological relevance. Interesting findings from array analysis were verified using qRT-PCR and immunohistochemical analysis. In addition, a xenograft mouse model was used to study the effects of abiraterone (steroidogenesis inhibitor) and cabazitaxel (taxane), and subsequently developed resistance mechanisms in the 22Rv1 PC cell line expressing high levels of AR-V7; a constitutively active AR splice variant associated with a poor prognosis and resistance to AR targeting therapies.In summary, results showed that the majority of CRPC bone metastases were AR-driven, defined from high levels of AR-regulated gene transcripts, while a smaller sub-group was non-AR-driven (paper I). AR-driven bone metastases had high metabolic activity in combination with downregulated immune responses while non-AR-driven cases had a more pronounced immune response (paper I) and higher bone cell activity (paper II). Paper III identified pronounced hypermethylation in primary prostate tumors probably causing a suppressed anti-tumor immune-response whereas metastases showed a different methylation pattern related to increased AR activity and patient outcome. In paper IV, 22Rv1 xenografts showed poor response to abiraterone and initially excellent response to cabazitaxel, but eventually resistance occurred probably due to an upregulation of the ABCB1 transporter protein. Anti-androgens partly reversed the resistance.In conclusion, we have identified molecular heterogeneities in clinical bone metastases associated with biological characteristics, which could perhaps be used both for stratifying patients into treatment modalities, and to aid in further development of effective therapies for CRPC.
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