Tumor microenvironment derived biomarkers in renal cell cancer

Renal cell carcinoma (RCC) is the 13th most common malignancy worldwide, and constitutes around 2% of all malignant tumors. The entity renal cell carcinoma comprises a heterogenous group of malignant tumors that originates from the epithelial cells in the renal proximal tubule. The most frequently occurring subtype is clear cell renal cell carcinoma which is characterized by a mutation in the von-Hippel-Lindau gene leading to accumulation of hypoxia inducible factor and subsequent upregulation of growth factors involved in angiogenesis. RCC is inherently resistant to conventional chemotherapy, and thus radical surgery before metastasis has occurred still is the best chance for permanent cure. However, in recent years, the introduction of various targeted therapies and immunemodulators have changed the picture, and there are now numerous options which increases the hope for patients with metastatic disease. In this thesis, we investigated the tumor microenvironment to identify factors with impact on prognosis and response to anti-angiogenic therapy in patients with mRCC. We found that both high perivascular expression of PDGFR-β as well as high heterogeneity of perivascular PDGFR-β was significantly associated with shorter survival. In order to make an in-depth characterization of the tumor microenvironment, we compared vascular, perivascular and stromal features in renal, colorectal and ovarian cancer. This revealed significant differences regarding several metrics, but also similarities. We also studied the impact on tumor infiltrating B-lymphocytes in RCC and found that high infiltration conveyed a worse prognosis, counter to what is seen in many other tumor types, suggesting that high levels B-cells in RCC rather dampens the anti-tumor immune response than indicates an activated immune system. In the last paper, we investigated the role of intratumoral vessel size for response to anti-angiogenic treatment and found that tumors dominated by medium sized vessels was more sensitive to sunitinib. In summary, our findings indicate that the tumor microenvironment influences prognosis as well as response to treatment in a context dependent manner, and that this prompts further investigation within this field

Cellular High-Energy Cavitation Trauma - Description of a Novel In Vitro Trauma Model in Three Different Cell Types

The mechanisms involved in traumatic brain injury have yet to be fully characterized. One mechanism that, especially in high-energy trauma, could be of importance is cavitation. Cavitation can be described as a process of vaporization, bubble generation, and bubble implosion as a result of a decrease and subsequent increase in pressure. Cavitation as an injury mechanism is difficult to visualize and model due to its short duration and limited spatial distribution. One strategy to analyze the cellular response of cavitation is to employ suitable in vitro models. The flyer-plate model is an in vitro high-energy trauma model that includes cavitation as a trauma mechanism. A copper fragment is accelerated by means of a laser, hits the bottom of a cell culture well causing cavitation, and shock waves inside the well and cell medium. We have found the flyer-plate model to be efficient, reproducible, and easy to control. In this study, we have used the model to analyze the cellular response to microcavitation in SH-SY5Y neuroblastoma, Caco-2, and C6 glioma cell lines. Mitotic activity in neuroblastoma and glioma was investigated with BrdU staining, and cell numbers were calculated using automated time-lapse imaging. We found variations between cell types and between different zones surrounding the lesion with these methods. It was also shown that the injured cell cultures released S-100B in a dose-dependent manner. Using gene expression microarray, a number of gene families of potential interest were found to be strongly, but differently regulated in neuroblastoma and glioma at 24 h post trauma. The data from the gene expression arrays may be used to identify new candidates for biomarkers in cavitation trauma. We conclude that our model is useful for studies of trauma in vitro and that it could be applied in future treatment studies

A minority-group of renal cell cancer patients with high infiltration of CD20+B-cells is associated with poor prognosis

Background: The role of B-lymphocytes in solid tumours is unclear. Tumour biology studies have implied both anti- and pro-tumoural effects and prognostic studies have mainly linked B-cells to increased survival. This study aimed to analyse the clinical relevance of B-lymphocytes in renal cell cancer (RCC), where information on the prognostic impact is lacking. Methods: Following immunohistochemistry (IHC) stainings with a CD20 antibody, density of CD20+ B-cells was quantified in an RCC discovery- and validation cohort. Associations of B-cell infiltration, determined by CD20 expression or a B-cell gene-signature, and survival was also analysed in 14 publicly available gene expression datasets of cancer, including the kidney clear cell carcinoma (KIRC) dataset. Results: IHC analyses of the discovery cohort identified a previously unrecognised subgroup of RCC patients with high infiltration of CD20+ B-cells. The B-cell-high subgroup displayed significantly shorter survival according to uni- and multi-variable analyses. The association between poor prognosis and high density of CD20+ B-cells was confirmed in the validation cohort. Analyses of the KIRC gene expression dataset using the B-cell signature confirmed findings from IHC analyses. Analyses of other gene expression datasets, representing 13 different tumour types, indicated that the poor survival-association of B-cells occurred selectively in RCC. Conclusion: This exploratory study identifies a previously unrecognised poor-prognosis subset of RCC with high density of CD20-defined B-cells

A novel oral insulin-like growth factor-1 receptor pathway modulator and its implications for patients with non-small cell lung carcinoma: A phase I clinical trial

<p><b>Background.</b> A phase Ia/b dose-escalation study was performed to characterize the safety, efficacy and pharmacokinetic properties of the oral small molecule insulin-like growth factor-1-receptor pathway modulator AXL1717 in patients with advanced solid tumors.</p> <p><b>Material and methods.</b> This was a prospective, single-armed, open label, dose-finding phase Ia/b study with the aim of single day dosing (phase Ia) to define the starting dose for multi-day dosing (phase Ib), and phase Ib to define and confirm recommended phase II dose (RP2D) and if possible maximum tolerated dose (MTD) for repeated dosing.</p> <p><b>Results and Conclusion.</b> Phase Ia enrolled 16 patients and dose escalations up to 2900 mg BID were successfully performed without any dose limiting toxicity (DLT). A total of 39 patients were treated in phase Ib. AXL1717 was well tolerated with neutropenia as the only dose-related, reversible, DLT. RP2D dose was found to be 390 mg BID for four weeks. Some patients, mainly with NSCLC, demonstrated signs of clinical benefit, including four partial tumor responses (one according to RECIST and three according to PET). The 15 patients with NSCLC with treatment duration longer than two weeks with single agent AXL1717 in third or fourth line of therapy showed a median progression-free survival of 31 weeks and overall survival of 60 weeks. Down-regulation of IGF-1R on granulocytes and increases of free serum levels of IGF-1 were seen in patients treated with AXL1717. AXL1717 had an acceptable safety profile and demonstrated promising efficacy in this heavily pretreated patient cohort, especially in patients with NSCLC. RP2D was concluded to be 390 mg BID for four weeks. Trial number is NCT01062620.</p

Perivascular PDGFR-β is an independent marker for prognosis in renal cell carcinoma

Background:Renal cell carcinoma (RCC) is a highly vascularised tumour, where anti-Angiogenic treatment with multi-Tyrosine-kinase-inhibitor, is used for first-line treatment of metastatic disease. Variations in vascular characteristics are likely to contribute to variations in intrinsic aggressiveness of the disease. Emerging studies are identifying perivascular status, including perivascular PDGFR-β, as a determinant of prognosis in other tumour types.Methods:This work explored the impact on prognosis of vascular characteristics in RCC through analyses of a population-based collection of tumours from surgery-Alone-Treated patients. The quantitative data from a panel of vascular metrics were obtained through computerised image analysis of sections double-stained for expression of the endothelial cell marker CD34 together with perivascular markers α-SMA or PDGFR-β.Results:Perivascular expression of PDGFR-β and α-SMA were positively correlated to each other, and negatively correlated to vessel density. High expression of PDGFR-β and α-SMA as well as low vessel density was significantly associated with short survival in uni-and multivariate analyses. Subgroup analyses demonstrated that the prognostic impact of the perivascular markers was particularly prominent in the T4-subgroup. A novel metric, related to PDGFR-β perivascular heterogeneity, was also associated with prognosis in uni-And multi-variate analyses. This novel metric also acted as a prognosis marker in ovarian cancer.Conclusions:The study demonstrates previously unrecognised associations between RCC survival and the absolute levels, and variability, of perivascular PDGFR-β. This marker should be further explored in other RCC cohorts. Findings also suggest mechanistic analyses and studies on the relationship between perivascular status and efficacy of multi-Tyrosine-kinase-inhibitors

A minority-group of renal cell cancer patients with high infiltration of CD20+B-cells is associated with poor prognosis

Background: The role of B-lymphocytes in solid tumours is unclear. Tumour biology studies have implied both anti- and pro-tumoural effects and prognostic studies have mainly linked B-cells to increased survival. This study aimed to analyse the clinical relevance of B-lymphocytes in renal cell cancer (RCC), where information on the prognostic impact is lacking. Methods: Following immunohistochemistry (IHC) stainings with a CD20 antibody, density of CD20+ B-cells was quantified in an RCC discovery- and validation cohort. Associations of B-cell infiltration, determined by CD20 expression or a B-cell gene-signature, and survival was also analysed in 14 publicly available gene expression datasets of cancer, including the kidney clear cell carcinoma (KIRC) dataset. Results: IHC analyses of the discovery cohort identified a previously unrecognised subgroup of RCC patients with high infiltration of CD20+ B-cells. The B-cell-high subgroup displayed significantly shorter survival according to uni- and multi-variable analyses. The association between poor prognosis and high density of CD20+ B-cells was confirmed in the validation cohort. Analyses of the KIRC gene expression dataset using the B-cell signature confirmed findings from IHC analyses. Analyses of other gene expression datasets, representing 13 different tumour types, indicated that the poor survival-association of B-cells occurred selectively in RCC. Conclusion: This exploratory study identifies a previously unrecognised poor-prognosis subset of RCC with high density of CD20-defined B-cells