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Showing posts with the label signaling

Turned-off Cannabinoid Receptor Turns On Colorectal Tumor Growth

New preclinical research shows that cannabinoid cell surface receptor CB1 plays a tumor-suppressing role in human colorectal cancer, scientists report in the Aug. 1 edition of the journal Cancer Research. Endocannabinoid signaling is important to the normal functioning of the digestive system and has been shown to protect the colon against inflammation. Since chronic inflammation is a known risk factor for colorectal cancer, the researchers decided to look into the role of cannabinoid receptors in a mouse model of colon cancer. Cannabinoids previously had been shown to kill cancer cells in lab experiments by inducing apoptosis - programmed cell death. The team confirmed the role of CB1 in apoptosis, showing that tumor cells with high CB1 expression were sensitive to apoptosis when treated by a cannabinoid agonist. Cell lines with silenced CB1 resisted cell death. A series of experiments showed that CB1 increases cancer cell death by stifling a protein called survivin. Survivin is ov...

Elevated Levels of Metabolites in CSF Play a Role in HIV Patients with CNS Damage

A team of scientists from The Scripps Research Institute found an increased concentration of certain metabolites in the cerebrospinal fluid (CSF) of monkeys with SIV-induced central nervous system (CNS) disease, a model for HIV patients with CNS damage. The investigators used global metabolomics to assess the levels of metabolites in CSF before and after SIV-induced encephalitis appeared. They found elevated levels in four categories: carnitine, acyl-carnitines, fatty acids, and phospholipids. Consistent with this, the team reports, a protein known to be important in the generation of fatty acids was increased in the brains of monkeys with SIV-induced encephalitis. The elevation in free fatty acids and lysophospholipids correlated with increased expression of specific phospholipases in the brains of animals with encephalitis, according to the researchers. One of these, phospholipase A2 isoenzyme, is capable of releasing a number of the fatty acids identified. It was expressed in d...