Maspin controls mammary tumor cell migration through inhibiting Rac1 and Cdc42, but not the RhoA GTPase.

Rac1 and Cdc42 are members of the Rho family of small GTPases that play essential roles in diverse cellular functions, including cell migration. The activities of these Rho family proteins are controlled by growth factor receptor activation and cell-ECM interactions. Here, we show that maspin, a well-documented tumor suppressor gene, also controls cell motility through inhibiting Rac1/Cdc42 activity.

Increased expression of prostate-specific G-protein-coupled receptor in human prostate intraepithelial neoplasia and prostate cancers.

The G-protein-coupled receptors and signal transduction pathways represent important specific targets for a variety of human diseases, ranging from the control of blood pressure, allergic response, hormonal disorders and neurologic diseases to tumorigenesis. Most recently, we and others have identified a novel human prostate-specific G-protein coupled receptor (PSGR). To investigate the potential roles of PSGR in human normal prostate and prostate cancers, we examined the expression level of PSGR in 146 human prostate samples with real-time quantitative reverse transcription-PCR and in situ hybridization method.

GEFT, a Rho family guanine nucleotide exchange factor, regulates neurite outgrowth and dendritic spine formation.

The Rho family of small GTPases controls a wide range of cellular processes in eukaryotic cells, such as normal cell growth, proliferation, differentiation, gene regulation, actin cytoskeletal organization, cell fate determination, and neurite outgrowth. The activation of Rho-GTPases requires the exchange of GDP for GTP, a process catalyzed by the Dbl family of guanine nucleotide exchange factors. We demonstrate that a newly identified guanine nucleotide exchange factor, GEFT, is widely expressed in the brain and highly concentrated in the hippocampus, and the Purkinje and granular cells of the cerebellum.

GGAPs, a new family of bifunctional GTP-binding and GTPase-activating proteins.

G proteins are molecular switches that control a wide variety of physiological functions, including neurotransmission, transcriptional activation, cell migration, cell growth. and proliferation. The ability of GTPases to participate in signaling events is determined by the ratio of GTP-bound to GDP-bound forms in the cell.

A Rac/Cdc42-specific exchange factor, GEFT, induces cell proliferation, transformation, and migration.

The Rho family of small GTPases, including Rho, Rac, and Cdc42, play essential roles in diverse cellular functions. The ability of Rho family GTPases to participate in signaling events is determined by the ratio of inactive (GDP-bound) and active (GTP-bound) forms in the cell. The activation of Rho family proteins requires the exchange of bound GDP for GTP, a process catalyzed by the Dbl family of guanine nucleotide exchange factors (GEFs).

Curcumin-induced suppression of cell proliferation correlates with down-regulation of cyclin D1 expression and CDK4-mediated retinoblastoma protein phosphorylation.

Cyclin D1 is a proto-oncogene that is overexpressed in many cancers including breast and prostate. It plays a role in cell proliferation through activation of cyclin-dependent kinases. Curcumin, a diferuloylmethane, is a chemopreventive agent known to inhibit the proliferation of several breast and prostate cancer cell lines.

Identification and characterization of mouse metastasis-suppressor KiSS1 and its G-protein-coupled receptor.

G-protein-coupled receptors receive many different signals to activate different functions such as cellgrowth, proliferation, and migration. KiSS1 is a metastasis suppressor gene that has been shown to inhibit metastasis of human melanomas and breast carcinomas. The human KiSS1 gene encodes a COOH-terminally amidated active peptide, and this peptide is the ligand of a novel G-protein-coupled receptor.