The tubules of the kidney display a remarkable capacity for self-renewal on damage. Whether this regeneration is mediated by dedifferentiating surviving cells or, as recently suggested, by stem cells has not been unequivocally settled. Herein, we demonstrate that aldehyde dehydrogenase (ALDH) activity may be used for isolation of cells with progenitor characteristics from adult human renal cortical tissue. Gene expression profiling of the isolated ALDH high and ALDH low cell fractions followed by immunohistochemical interrogation of renal tissues enabled us to delineate a tentative progenitor cell population scattered through the proximal tubules (PTs). These cells expressed CD24 and

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This is the first study demonstrating an overexpression of 5-HTR subtypes 1A and 1B in PC cells, especially in high-grade tumors. Moreover, 5-HT stimulates proliferation of PC cells and 5-HTR1A antagonists inhibit proliferation. Thus, we propose that 5-HT has an important role in tumor progression, especially in the androgen-independent state of the disease. The design of specific antagonists for this type of receptor might be useful for the growth control of androgen-independent tumors.

Exposure of metazoan organisms to hypoxia engages a metabolic switch orchestrated by the hypoxia-inducible factor 1 (HIF-1). HIF-1 mediates induction of glycolysis and active repression of mitochondrial respiration that reduces oxygen consumption and inhibits the production of potentially harmful reactive oxygen species (ROS). Here, we show that FoxO3A is activated in hypoxia downstream of HIF-1 and mediates the hypoxic repression of a set of nuclear-encoded mitochondrial genes. FoxO3A is required for hypoxic suppression of mitochondrial mass, oxygen consumption, and ROS production and promotes cell survival in hypoxia. FoxO3A is recruited to the promoters of nuclear-encoded mitochondrial genes where it directly antagonizes c-Myc function via a mechanism that does not require binding to the consensus FoxO recognition element. Furthermore, we show that FoxO3A is activated in human hypoxic tumour tissue in vivo and that FoxO3A shorthairpin RNA (shRNA)-expressing xenograft tumours are decreased in size and metabolically changed. Our findings define a novel mechanism by which FoxO3A promotes metabolic adaptation and stress resistance in hypoxia.

Recurrent prostate cancer remains a major clinical challenge. The lysine specific demethylase-1 (LSD1/KDM1A), together with the JmjC domain-containing JMJD2A and JMJD2C proteins, have emerged as critical regulators of histone lysine methylation. The LSD1-JMJD2 complex functions as a transcriptional co-regulator of hormone activated androgen and estrogen receptors at specific gene promoters. LSD1 also regulates DNA methylation and p53 function. LSD1 is overexpressed in numerous cancers including prostate cancer through an unknown mechanism. We investigated expression of the LSD1 and JMJD2A in malignant human prostate specimens. We correlated LSD1 and JMJD2A expression with known mediators of prostate cancer progression: VEGF-A and cyclin A1. We show that elevated expression of LSD1, but not JMJD2A, correlates with prostate cancer recurrence and with increased VEGF-A expression. We show that functional depletion of LSD1 expression using siRNA in prostate cancer cells decreases VEGF-A and blocks androgen induced VEGF-A, PSA and Tmprss2 expression. We demonstrate that pharmacological inhibition of LSD1 reduces proliferation of both androgen dependent (LnCaP) and independent cell lines (LnCaP:C42, PC3). We show a direct mechanistic link between LSD1 over-expression and increased activity of pro-angiogenic pathways. New therapies targeting LSD1 activity should be useful in the treatment of hormone dependent and independent prostate cancer.

BackgroundCyclin A1 is a cell cycle regulator that has been implicated in the progression of prostate cancer. Its role in invasion and metastasis of this disease has not been characterized.MethodsImmunohistochemistry and cDNA microarray analyses were used to assess protein and mRNA expression of cyclin A1 and proteins with roles in metastasis, including vascular endothelial growth factor (VEGF), metalloproteinase 2 (MMP2), and MMP9, in human prostate cancer. Transient transfection and infection with viral vectors expressing cyclin A1 and short hairpin RNA (shRNA) targeting cyclin A1 were used to study the effects of altered cyclin A1 expression in PC3 prostate cancer cells. The BrdU assay, annexin V staining, and invasion chambers were used to examine cyclin A1 effects on proliferation, apoptosis, and invasion, respectively. The role of cyclin A1 and androgen receptor (AR) in transcription of VEGF and MMP2 was assessed by promoter mutation and chromatin immunoprecipitation. The effect of cyclin A1 expression on tumor growth and metastasis was analyzed in a mouse model of metastasis. All statistical tests were two-sided.ResultsCyclin A1 protein and mRNA expression were statistically significantly higher in prostate cancers than in adjacent benign tissues. A statistically significant correlation between expression of cyclin A1 and of MMP2, MMP9, and VEGF was observed in prostate tumors from 482 patients (P values from Spearman rank correlation tests < .001). PC3 cells that overexpressed cyclin A1 showed increased invasiveness, and inhibition of cyclin A1 expression via shRNA expression reduced invasiveness of these cells. Eight of 10 mice (80%) bearing PC3 cells overexpressing cyclin A1 had infiltration of tumor cells in lymph node, liver, and lung, but all 10 mice bearing tumors expressing control vector were free of liver and lung metastases and only one mouse from this group had lymph node metastasis (P values from Fisher exact tests < .001). Cyclin A1, in concert with AR, bound to and increased expression from the VEGF and MMP2 promoters.ConclusionsCyclin A1 contributes to prostate cancer invasion by modulating the expression of MMPs and VEGF and by interacting with AR.

BackgroundAltered androgen hormone homeostasis and androgen receptor (AR) activity have been implicated in ovarian carcinogenesis but the relationship between AR expression in ovarian cancer and clinical outcome remains unclear.MethodsIn this study, the prognostic impact of AR expression was investigated using immunohistochemistry in tissue microarrays from 154 incident cases of epithelial ovarian cancer (EOC) in the prospective, population-based cohorts Malmö Diet and Cancer Study and Malmö Preventive Project. A subset of corresponding fallopian tubes (n = 36) with no histopathological evidence of disease was also analysed.ResultsWhile abundantly expressed in the majority of fallopian tubes with more than 75% positive nuclei in 16/36 (44%) cases, AR was absent in 108/154 (70%) of EOC cases. AR expression was not related to prognosis in the entire cohort, but in the serous subtype (n = 90), AR positivity (> 10% positive nuclei) was associated with a prolonged disease specific survival in univariate (HR= 0.49; 95% CI 0.25-0.96; p= 0.038) and multivariate (HR= 0.46; 95% CI 0.22-0.97; p= 0.042) analysis, adjusted for age, grade and clinical stage.ConclusionsAR expression is considerably reduced in EOC as compared to fallopian tubes, and in EOC of the serous subtype, high AR expression is a favourable prognostic factor. These results indicate that assessment of AR expression might be of value for treatment stratification of EOC patients with serous ovarian carcinoma.

Background: γ-Tubulin moderates the expression of E2F-regulated promoters by direct binding to DNA.Results: RB1 and γ-tubulin proteins moderate each other's expression by binding to their respective gene promoters.Conclusion: Reduction of γ-tubulin protein levels in tumors with nonfunctional RB1 leads to induction of apoptosis.Significance: The RB1/γ-tubulin signal network can be considered as a new target for cancer treatment.