Nischarin may be a novel tumor suppressor that limits breast cancer progression by regulating α5 integrin expression and subsequently α5 integrin-, FAK-, and Rac-mediated signaling.

D9 -Tetrahydrocannabinol (D 9 -THC), the primary psychoactive component in marijuana, is FDA approved to ameliorate AIDS-associated wasting. Because cannabinoid receptors are expressed on cells of the immune system, chronic D 9 -THC use may impact HIV disease progression. We examined the impact of chronic D 9-THC administration (0.32 mg/kg im, 2Âdaily), starting 28 days prior to inoculation with simian immunodeficiency virus (SIV mac251 ; 100 TCID 50 /ml, iv), on immune and metabolic indicators of disease during the initial 6 month asymptomatic phase of infection in rhesus macaques. SIV mac251 inoculation resulted in measurable viral load, decreased lymphocyte CD4 þ /CD8 þ ratio, and increased CD8 þ proliferation. D 9 -THC treatment of SIV-infected animals produced minor to no effects in these parameters. However, chronic D 9 -THC administration decreased early mortality from SIV infection ( p ¼ 0.039), and this was associated with attenuation of plasma and CSF viral load and retention of body mass ( p ¼ NS). In vitro, D 9 -THC (10 mm) decreased SIV (10 TCID 50 ) viral replication in MT4-R5 cells. These results indicate that chronic D 9 -THC does not increase viral load or aggravate morbidity and may actually ameliorate SIV disease progression. We speculate that reduced levels of SIV, retention of body mass, and attenuation of inflammation are likely mechanisms for D 9 -THC-mediated modulation of disease progression that warrant further study.T he cannabinoids including cannabidiol, cannabinol, and D 9 -tetrahydrocannabinol (D 9 -THC) exert their effects by binding to two major subtypes of cannabinoid receptor, CB1 and CB2.1 The CB1 receptor is preferentially expressed in the brain where it mediates neurobehavioral effects. The CB2 receptor is expressed primarily in peripheral tissues, particularly in immune cells where they have been shown to affect cytokine production, lymphocyte phenotype, function and survival, cell-mediated immunity, and balance of Th1/ Th2 cells.2 With the advent of highly active antiretroviral therapy (HAART), human immunodeficiency virus (HIV) infection has become a chronic disease frequently coexisting with chronic use of drugs of abuse, including marijuana. Using a well-established nonhuman primate model of HIV disease, we examined the impact of chronic intramuscular D 9 -THC (provided by the National Institute on Drug Abuse, Research Technical Branch, Rockville, MD) administration on the early phase of simian immunodeficiency virus (SIV) infection in age-matched (4-6 years old) and body weight-matched healthy male Indian-derived rhesus macaques. Chronic administration of D 9 -THC [or 0.05 ml/kg vehicle (VEH)] was initiated prior to SIV with 0.18 mg/kg, a dose that eliminated responding in a complex operant behavioral task in almost all of the subjects. The dose was subsequently increased for each subject to 0.32 mg/kg, over