MicroRNA-7 suppresses the homing and migration potential of human endothelial cells to highly metastatic human breast cancer cells.

BACKGROUND: MicroRNA-7 (miR-7) has been observed as a potent tumour suppressor in multiple cancer types including breast cancer. The aim of this study was to investigate the response sensitivities of metastatic breast cancer cells to miR-7 and the roles of miR-7 in the interaction of endothelial cells and metastatic cancer cells. METHODS: Expression profile of miRNAs in a breast cancer specimen cohort and breast cancer cells were determined using real-time quantitative miRNA assays. Effect of the altering expression of miR-7 on migration, invasion, proliferation, interaction and underlying molecular mechanism of breast cancer cells and endothelial cells was investigated after treatment with the synthesised mimic of miR-7. Luciferase activity analysis was performed to validate Wave-3 as a novel target of miR-7. RESULTS: miR-7 expression was negatively correlated with the stage, grade and survival of the breast cancer patients. There was also differential expression of miRNAs including miR-7 in the breast cancer cells. The synthesised mimic of miR-7 inhibits the motility and wound healing potential of breast cancer cells. The highly metastatic MDA-MB-231 cells are more sensitive to the miR-7 treatment than the poorly invasive MCF-7 cells. Treatment with miR-7 downregulated the expression of EGFR, IGF1R and Wave3 in MDA-MB-231 cells but not in MCF-7 cells. In addition, we further demonstrated that miR-7 inhibited the proliferation, migration and invasion of endothelial cells. And more importantly, miR-7 suppressed the homing and migration of endothelial cells to more aggressive tumour cell conditions. CONCLUSIONS: Given the dual inhibitory effect of miR-7 on metastatic breast cancer cells alone and the interaction of endothelial cells with the tumour-conditioned microenvironment, we suggest miR-7 may be a new therapeutic candidate for its capacity not only to prevent breast cancer cell spreading but also to inhibit tumour-associated angiogenesis in the metastatic breast cancer.

MDM2 and PSMA Play Inhibitory Roles in Metastatic Breast Cancer Cells Through Regulation of Matrix Metalloproteinases.

BACKGROUND/AIM: Mouse double minute 2 (MDM2) and prostate-specific membrane antigen (PSMA) are currently under investigation as individual therapeutic targets due to their overexpression in many cancer types, as well as their pro-tumorigenic effect on cells. Recently, knockdown of PSMA was linked to a decrease in MDM2 and matrix metalloproteinase 2 (MMP2) and an increase in MMP3 and MMP13 expression. We aimed to assess the link between PSMA, MDM2 and the MMPs in metastatic breast cancer cell lines. MATERIALS AND METHODS: Real-time quantitative polymerase chain reaction (PCR) and western blotting were used to assess siRNA-mediated knockdown of MDM2 and PSMA in MDA-MB-231 and ZR-75.1 breast cancer cells. Assays to assess the growth, adhesion, migration and invasion of the cells following siRNA treatment were undertaken. MMP and tissue inhibitor of matrix metalloproteinases (TIMP) levels were assessed via quantitative PCR. RESULTS: Knockdown of MDM2 resulted in a decrease in PSMA expression levels and vice versa; although this trend was not replicated at the protein level. Knockdown of each of the molecules resulted in a decrease in growth, adhesion, migration and invasive ability of breast cancer cells. Both knockdowns led to a decrease in MMP2 and an increase in MMP3, -10 and -13 gene expression. CONCLUSION: MDM2 and PSMA may co-regulate the expression of certain MMPs and, thus, the functionality of cells in metastatic breast cancer.

The clinical and therapeutic uses of MDM2 and PSMA and their potential interaction in aggressive cancers.

Prostate-specific membrane antigen (PSMA) overexpression is observed in the neovasculature of solid tumors, but not in the vasculature of normal tissues. Increased PSMA expression is positively associated with tumor stage and grade, although its function in cancer remains unclear. Mouse double minute 2 (MDM2) is a negative regulator of the p53 tumor suppressor and is reported to regulate VEGF expression and angiogenesis. Both proteins have been considered as biomarkers and therapeutic targets for advanced solid tumors. Our work and a recent microarray-based gene profiling study suggest there could be signaling interplay between MDM2 and PSMA. We herein review the mechanisms underlining the outgrowth of tumors associated with PSMA and MDM2, their potential interaction and how this may be applied to anticancer therapeutics.

Cannabis-sensitive dopaminergic markers in postmortem central nervous system: changes in schizophrenia.

BACKGROUND: This study investigated if changes in pre-synaptic markers on dopaminergic neurons (dopamine transporter [DAT], tyrosine hydroxylase [TH]) were present in the caudate from subjects with schizophrenia who had Delta(9)(-)tetrahydrocannabinol (THC) in their blood at autopsy. These changes were posited because animal studies show that treatment with THC decreases dopamine uptake and TH in the striatum. METHODS: Studies utilized caudate, obtained postmortem, from 14 schizophrenic and 14 control subjects. [(3)H]mazindol binding to caudate, measured using autoradiography, was taken as a measure of DAT; TH levels were estimated using an antihuman TH antibody and Western blotting. RESULTS: There was decreased [(3)H]mazindol binding to DAT in the caudate from the schizophrenic subjects with no detectable blood THC levels (THC(-)) compared with THC(-) control subjects (mean +/- SEM: 240 +/- 19 vs. 296 +/- 14 fmol/mg estimated tissue equivalents, p =.01). There were no significant differences between levels of DAT in the caudate from schizophrenic and control subjects that had THC in their blood. Tyrosine hydroxylase was not different in any diagnostic cohort. CONCLUSIONS: Our data suggests that DAT is decreased in the caudate from THC(-) subjects with schizophrenia, a change that may be reversed by ingesting THC from cannabis.

A comparative, single-blind, randomized trial of pain associated with suction or non-suction drains after gynecologic laparoscopy.

STUDY OBJECTIVE: To estimate the difference in pain associated with the wearing or removal of suction or non-suction drains after gynecologic laparoscopic surgery. DESIGN: A randomized controlled trial from August 2006 through October 2007 (Canadian Task Force Classification I). SETTING: Royal Hospital for Women, Department of Endo-Gynaecology and School of Women's and Children's Health University of New South Wales. PATIENTS: A total of 168 women undergoing gynecologic laparoscopy requiring postoperative drainage. INTERVENTIONS: Patients were randomized to receive either a suction or non-suction drain after surgery. MEASUREMENTS AND MAIN RESULTS: Pain was assessed before, during, and after drain removal with a 4-point verbal descriptor scale and 10-cm visual analogue scale. Visual analogue scale and verbal descriptor scale scores for suction versus non-suction groups were 3 versus 3 (p=.654) and 1 versus 1 (p=.686) before removal, 9 versus 7 (p=.016) and 3 versus 2 (p=.029) during removal, and 7 versus 5 (p=.058) and 2 versus 2 (p=.122) after removal. CONCLUSION: There is no significant difference in patient discomfort while wearing or after removal of suction or non-suction drains. However, suction drains are more painful to have removed.