am-356 and Uterine-Cervical-Neoplasms

Cannabinoids have received renewed interest due to their antitumorigenic effects. Using human cervical carcinoma cells (HeLa), this study investigates the role of cyclooxygenase-2 (COX-2) in apoptosis elicited by the endocannabinoid analog R(+)-methanandamide (MA).. COX-2 expression was assessed by RT-PCR and Western blotting. PGE2/PGD2 levels in cell culture supernatants and DNA fragmentation were measured by ELISA.. MA led to an induction of COX-2 expression, PGD2 and PGE2 synthesis. Cells were significantly less sensitive to MA-induced apoptosis when COX-2 was suppressed by siRNA or the selective COX-2 inhibitor NS-398. COX-2 expression and apoptosis by MA was also prevented by the ceramide synthase inhibitor fumonisin B1, but not by antagonists to cannabinoid receptors and TRPV1. In line with the established role of peroxisome proliferator-activated receptor gamma (PPARgamma) in the proapoptotic action of PGs of the D and J series, inhibition of MA-induced apoptosis was also achieved by siRNA targeting lipocalin-type PGD synthase (L-PGDS) or PPARgamma. A role of COX-2 and PPARgamma in MA-induced apoptosis was confirmed in another human cervical cancer cell line (C33A) and in human lung carcinoma cells (A549).. This study demonstrates COX-2 induction and synthesis of L-PGDS-derived, PPARgamma-activating PGs as a possible mechanism of apoptosis by MA.

Topics: Antineoplastic Agents; Apoptosis; Arachidonic Acids; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Dinoprostone; DNA Fragmentation; Dose-Response Relationship, Drug; Female; Fumonisins; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; HeLa Cells; Humans; Intramolecular Oxidoreductases; Lipocalins; Nitrobenzenes; Oxidoreductases; PPAR gamma; Prostaglandin D2; RNA Interference; RNA, Messenger; RNA, Small Interfering; Sulfonamides; Time Factors; Uterine Cervical Neoplasms

Cannabinoids, in addition to having palliative benefits in cancer therapy, have been associated with anticarcinogenic effects. Although the antiproliferative activities of cannabinoids have been intensively investigated, little is known about their effects on tumor invasion.. Matrigel-coated and uncoated Boyden chambers were used to quantify invasiveness and migration, respectively, of human cervical cancer (HeLa) cells that had been treated with cannabinoids (the stable anandamide analog R(+)-methanandamide [MA] and the phytocannabinoid delta9-tetrahydrocannabinol [THC]) in the presence or absence of antagonists of the CB1 or CB2 cannabinoid receptors or of transient receptor potential vanilloid 1 (TRPV1) or inhibitors of p38 or p42/44 mitogen-activated protein kinase (MAPK) pathways. Reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblotting were used to assess the influence of cannabinoids on the expression of matrix metalloproteinases (MMPs) and endogenous tissue inhibitors of MMPs (TIMPs). The role of TIMP-1 in the anti-invasive action of cannabinoids was analyzed by transfecting HeLa, human cervical carcinoma (C33A), or human lung carcinoma cells (A549) cells with siRNA targeting TIMP-1. All statistical tests were two-sided.. Without modifying migration, MA and THC caused a time- and concentration-dependent suppression of HeLa cell invasion through Matrigel that was accompanied by increased expression of TIMP-1. At the lowest concentrations tested, MA (0.1 microM) and THC (0.01 microM) led to a decrease in invasion (normalized to that observed with vehicle-treated cells) of 61.5% (95% CI = 38.7% to 84.3%, P < .001) and 68.1% (95% CI = 31.5% to 104.8%, P = .0039), respectively. The stimulation of TIMP-1 expression and suppression of cell invasion were reversed by pretreatment of cells with antagonists to CB1 or CB2 receptors, with inhibitors of MAPKs, or, in the case of MA, with an antagonist to TRPV1. Knockdown of cannabinoid-induced TIMP-1 expression by siRNA led to a reversal of the cannabinoid-elicited decrease in tumor cell invasiveness in HeLa, A549, and C33A cells.. Increased expression of TIMP-1 mediates an anti-invasive effect of cannabinoids. Cannabinoids may therefore offer a therapeutic option in the treatment of highly invasive cancers.

Topics: Arachidonic Acids; Biocompatible Materials; Cannabinoid Receptor Antagonists; Cannabinoids; Cell Movement; Collagen; Cytological Techniques; Down-Regulation; Dronabinol; Drug Combinations; Female; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; HeLa Cells; Humans; Immunoblotting; Laminin; Lung Neoplasms; Matrix Metalloproteinase 1; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Neoplasm Invasiveness; p38 Mitogen-Activated Protein Kinases; Protein Kinase Inhibitors; Proteoglycans; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Signal Transduction; Tissue Inhibitor of Metalloproteinase-1; Transfection; TRPV Cation Channels; Uterine Cervical Neoplasms