Entity

Time filter

Source Type

Bergen, Norway

Rogers M.S.,Harvard University | Cryan L.M.,Harvard University | Blois A.,Center for Cancer Biomarkers | Bo T.H.,Haukeland University Hospital | And 10 more authors.
Molecular Cancer Research | Year: 2014

The angiogenic switch, a rate-limiting step in tumor progression, has already occurred by the time most human tumors are detectable. However, despite significant study of the mechanisms controlling this switch, the kinetics and reversibility of the process have not been explored. The stability of the angiogenic phenotype was examined using an established human liposarcoma xenograft model. Nonangiogenic cells inoculated into immunocompromised mice formed microscopic tumors that remained dormant for approximately 125 days (vs. <40 days for angiogenic cells) whereupon the vast majority (>95%) initiated angiogenic growth with second-order kinetics. These original, clonally derived angiogenic tumor cells were passaged through four in vivo cycles. At each cycle, a new set of single-cell clones was established from the most angiogenic clone and characterized for in vivo for tumorigenic activity. A total of 132 single-cell clones were tested in the second, third, and fourth in vivo passage. Strikingly, at each passage, a portion of the single-cell clones formed microscopic, dormant tumors. Following dormancy, like the original cell line, these revertant tumors spontaneously switched to the angiogenic phenotype. Finally, revertant clones were transcriptionally profiled and their angiogenic output determined. Collectively, these data demonstrate that the angiogenic phenotype in tumors is malleable and can spontaneously revert to the nonangiogenic phenotype in a population of human tumor cells. © 2014 American Association for Cancer Research. Source


Qu Y.,Gade Institute | Oyan A.M.,Gade Institute | Liu R.,Shanghai University | Hua Y.,Gade Institute | And 16 more authors.
Cancer Research | Year: 2013

How prostate cancer is initiated remains a topic of debate. In an effort to establish a human model of prostate carcinogenesis, we adapted premalignant human prostate EPT2-D5 cells to protein-free medium to generate numerous tight prostate spheres (D5HS) in monolayer culture. In contrast to EPT2-D5 cells, the newly generated D5HS efficiently formed large subcutaneous tumors and subsequent metastases in vivo, showing the tumorigenicity of D5HS spheres. A striking production of interleukin (IL)-6 mRNA and protein was found in D5HS cells. The essential roles of IL-6 and the downstream STAT3 signaling in D5HS tumor sphere formation were confirmed by neutralizing antibody, chemical inhibitors, and fluorescent pathway reporter. In addition, elevated reactive oxygen species (ROS) produced upon protein depletion was required for the activation of IL-6/STAT3 in D5HS. Importantly, a positive feedback loop was found between ROS and IL-6 during tumor sphere formation. The association of ROS/IL-6/STAT3 to the carcinogenesis of human prostate cells was further examined in xenograft tumors and verified by limiting dilution implantations. Collectively, we have for the first time established human prostate tumor-initiating cells based on physiologic adaption. The intrinsic association of ROS and IL-6/STAT3 signaling in human prostate carcinogenesis shed new light on this relationship and define therapeutic targets in this setting. ©2013 AACR. Source


Eefsen R.L.,Copenhagen University | Van Den Eynden G.G.,Translational Cancer Research Unit | Hoyer-Hansen G.,Copenhagen University | Brodt P.,McGill University | And 11 more authors.
Journal of Oncology | Year: 2012

The purpose of this study was to characterise growth patterns, proteolysis, and angiogenesis in colorectal liver metastases from chemonaive patients with multiple liver metastases. Twenty-four patients were included in the study, resected for a median of 2.6 metastases. The growth pattern distribution was 25.8 desmoplastic, 33.9 pushing, and 21 replacement. In 20 patients, identical growth patterns were detected in all metastases, but in 8 of these patients, a second growth pattern was also present in one or two of the metastases. In the remaining 4 patients, no general growth pattern was observed, although none of the liver metastases included more than two growth patterns. Overall, a mixed growth pattern was demonstrated in 19.3 of the liver metastases. Compared to metastases with pushing, those with desmoplastic growth pattern had a significantly up-regulated expression of urokinase-type plasminogen activator receptor (P = 0.0008). Angiogenesis was most pronounced in metastases with a pushing growth pattern in comparison to those with desmoplastic (P = 0.0007) and replacement growth pattern (P = 0.021). Although a minor fraction of the patients harboured metastases with different growth patterns, we observed a tendency toward growth pattern uniformity in the liver metastases arising in the same patient. The result suggests that the growth pattern of liver metastases is not a random phenomenon. © 2012 Rikke Lovendahl Eefsen et al. Source


Wik E.,University of Bergen | Birkeland E.,University of Bergen | Trovik J.,University of Bergen | Werner H.M.J.,University of Bergen | And 18 more authors.
Clinical Cancer Research | Year: 2013

Purpose: High Stathmin expression has recently been associated with clinical progress in endometrial cancers. Stathmin protein activity is modulated by phosphorylation, and the Serine38 site is one of four Stathmin phospho-sites. The presence and significance of pStathmin(S38) is largely unknown in human cancers, and we here examined the associations between this marker and tumor cell proliferation, clinicopathologic phenotype, and survival impact in endometrial cancer. A relationship with possible treatment targets was explored by integrated analysis of transcriptional alterations. Experimental Design: Primary endometrial cancers from two independent patient series (n = 518/n = 286) were analyzed. Biomarkers were assessed by immunohistochemistry, FISH, flow cytometry, DNA oligonucleotide microarray, single-nucleotide polymorphism array, and Sanger sequencing, and related to clinicopathologic annotations and follow-up information. Results: High pStathmin(S38) level was associated with poor prognosis, independent of other features, and correlated to increased tumor cell proliferation as well as high Stathmin levels. On the basis of transcriptional differences between high/low pStathmin(S38) tumors, phosphoinositide 3-kinase (PI3K)/mTOR/HSP90 were suggested as possible targets in pStathmin(S38)-high cases. High pStathmin(S38) was associated with several PI3K pathway alterations: amplification of the 3q26 region, increased PIK3CA copy number (FISH) and a PI3K activation score (all P < 0.05). Conclusions: High pStathmin(S38) is a novel biomarker of increased tumor cell proliferation and impaired prognosis as reported here for independent cohorts of endometrial cancer and not previously shown in human cancer. Our data support a rationale for further studies exploring effects of drugs inhibiting the PI3K signaling pathway in pStathmin(S38)-high endometrial cancer, including a potential value of pStathmin(S38) in predicting response to PI3K/mTOR/HSP90 inhibitors. ©2013 AACR. Source


Fogo A.B.,Vanderbilt University | Bostad L.,University of Bergen | Bostad L.,Gade Institute | Svarstad E.,University of Bergen | And 13 more authors.
Nephrology Dialysis Transplantation | Year: 2010

Background. In Fabry nephropathy, alpha-galactosidase deficiency leads to accumulation of glycosphingolipids in all kidney cell types, proteinuria and progressive loss of kidney function.Methods. An international working group of nephrologists from 11 Fabry centres identified adult Fabry patients, and pathologists scored histologic changes on renal biopsies. A standardized scoring system was developed with a modified Delphi technique assessing 59 Fabry nephropathy cases. Each case was scored independently of clinical information by at least three pathologists with an average final score reported.Results. We assessed 35 males (mean age 36.4 years) and 24 females (43.9 years) who mostly had clinically mild Fabry nephropathy. The average serum creatinine was 1.3 mg/dl (114.9 μmol/l); estimated glomerular filtration rate was 81.7 ml/min/1.73 m2 and urine protein to creatinine ratio was 1.08 g/g (122.0 mg/mmol). Males had greater podocyte vacuolization on light microscopy (mean score) and glycosphingolipid inclusions on semi-thin sections than females. Males also had significantly more proximal tubule, peritubular capillary and vascular intimal inclusions. Arteriolar hyalinosis was similar, but females had significantly more arterial hyalinosis. Chronic kidney disease stage correlated with arterial and glomerular sclerosis scores. Significant changes, including segmental and global sclerosis, and interstitial fibrosis were seen even in patients with stage 1-2 chronic kidney disease with minimal proteinuria.Conclusions. The development of a standardized scoring system of both disease-specific lesions, i.e. lipid deposition related, and general lesions of progression, i.e. fibrosis and sclerosis, showed a spectrum of histologic appearances even in early clinical stage of Fabry nephropathy. These findings support the role of kidney biopsy in the baseline evaluation of Fabry nephropathy, even with mild clinical disease. The scoring system will be useful for longitudinal assessment of prognosis and responses to therapy for Fabry nephropathy. © The Author 2010. Source

Discover hidden collaborations