IL-15 regulates migration, invasion, angiogenesis and genes associated with lipid metabolism and inflammation in prostate cancer.

Prostate cancer (PCa) is the most commonly diagnosed non-cutaneous cancer. In the United States it is second leading cause of cancer related deaths in men. PCa is often treated via radical prostatectomy (RP). However, 15-30% of the patients develop biochemical recurrence (i.e. increased serum prostate specific antigen (PSA) levels). Interleukin-15 (IL-15) is a secreted cytokine found over expressed in patients with recurrence-free survival after RP. In our study, we aim to determine the role of IL-15 in PCa using in vitro and in vivo models, and gene expression analysis. PC3 (androgen-independent) and 22RV1 (androgen-dependent) cell lines were treated with IL-15 at 0.0013 ng/mL and 0.1 ng/mL. Tumor growth was evaluated using an orthotopic xenograft model. The anterior prostate lobes of SCID mice were injected with 250,000 22RV1 cells and IL-15 was administered bi-weekly with intraperitoneal (IP) injections during 4 weeks. Tumor tissue was collected for immunohistochemical and gene expression analysis. To study changes in gene expression, we looked at "Tumor Metastasis" and "PI3K pathway" using commercially available PCR arrays. In addition, we employed a microarray approach using the Affymetrix Hugene 2.0 ST array chip followed by analysis with Ingenuity Pathways Analysis (IPA) software. In vitro studies showed that IL-15 decreased PCa cell motility at both concentrations. In vivo studies showed that IL-15 increased neutrophil infiltration, and the expression of adiponectin, desmin and alpha smooth muscle actin (α-sma) in the tumor tissue. Angiogenesis analysis, using CD31 immunohistochemistry, showed that IL-15 decreased the number of blood vessels. Gene expression analysis identified Cancer, Cell Death, Immune Response and Lipid Metabolism as the major diseases and functions altered in tumors treated with IL-15. This suggests that IL-15 causes inflammation and changes in stroma that can promote decreased tumor cell proliferation.

Central nervous system hemangiopericytoma, retrospective four year pathology case series.

Hemangiopericytomas (HPC) are uncommon, aggressive, difficult to diagnose tumors mostly found in the extremities and pelvis and very rarely within the Central Nervous System(CNS). CNS HPC closely mimics meningioma, which is a much more frequent benign tumor, while HPC is potentially lethal, thus correct diagnosis of HPC is vital. Due to the very low frequency of CNS HPC, local experience with this tumor is very limited. For this reason a retrospective four year review of CNS pathology cases was performed to observe the frequency of CNS HPC, histopathology, immunohistochemistry, correlate the proportion of HPCto meningiomas and compare these with the literature. Results showed that our past pathologic assessment of HPC as well as the incidence is consistent with the literature, while the ratio of HPC to meningioma was above expected. This is the first local study dealing with the pathology of CNS HPC, which discloses an adequate clinic-pathologic assessment within the UPR premises as reflected by pathologic-epidemiologic findings coincident with the literature. A discrepancy of the HPC to meningioma ratio was found. Further studies are warranted to delve into the etiologies of this discrepancy as the issue has major implications due to the benign and malignant behavior respectively of meningioma and HPC.