Small Molecule Inhibitors Targeting Gαi2 Protein Attenuate Migration of Cancer Cells

Abstract

Heterotrimeric G-proteins are ubiquitously expressed in several cancers, and they transduce signals from activated G-protein coupled receptors. These proteins have numerous biological functions, and they are becoming interesting target molecules in cancer therapy. Previously, we have shown that heterotrimeric G-protein subunit alphai2 (Gαi2) has an essential role in the migration and invasion of prostate cancer cells. Using a structure-based approach, we have synthesized optimized small molecule inhibitors that are able to prevent specifically the activation of the Gαi2 subunit, keeping the protein in its inactive GDP-bound state. We observed that two of the compounds (13 and 14) at 10 μΜ significantly inhibited the migratory behavior of the PC3 and DU145 prostate cancer cell lines. Additionally, compound 14 at 10 μΜ blocked the activation of Gαi2 in oxytocin-stimulated prostate cancer PC3 cells, and inhibited the migratory capability of DU145 cells overexpressing the constitutively active form of Gαi2, under basal and EGF-stimulated conditions. We also observed that the knockdown or inhibition of Gαi2 negatively regulated migration of renal and ovarian cancer cell lines. Our results suggest that small molecule inhibitors of Gαi2 have potential as leads for discovering novel anti-metastatic agents for attenuating the capability of cancer cells to spread and invade to distant sites.

Preventive Effect of Limosilactobacillus fermentum SCHY34 on Lead Acetate-Induced Neurological Damage in SD Rats

“…It is currently believed that when certain nerve cells are excited, the presynaptic nerve terminals release transmitters to act on the corresponding receptors on the postsynaptic membrane to activate AC and catalyze the synthesis of adenosine triphosphate (ATP) in the postsynaptic membrane, which in turn activates PKA ( 52 ). PKA activation causes phosphorylation of the downstream target cyclic adenosine p -CREB ( 53 ). p -CREB promotes the transcription of BDNF, immediate early genes c-fos and c-jun, and SYN, and forms new synaptic connections.…”

Gαi2 Protein Inhibition Blocks Chemotherapy- and Anti-Androgen-Induced Prostate Cancer Cell Migration

“…LNCaP human AR+ (ATCC ® CRL-1740™), DU145 (ATCC ® HTB-81™) and PC3 human AR− (ATCC ® CRL-1435™) prostate cancer cell lines were obtained from the American Type Culture Collection (ATCC) (Rockville, MD, USA). They were maintained as previously described [7,8], and they were tested periodically for mycoplasma contamination using PlasmoTest™-Mycoplasma Detection Kit (InvivoGen, San Diego, CA, USA). Antiα-tubulin and bovine serum albumin (BSA) were obtained from Sigma-Aldrich (St. Louis, MO, USA).…”

“…Anti-androgens were prepared at a stock concentration of 100 mM (enzalutamide) and 10 mM (bicalutamide) in DMSO. The Gα i 2 inhibitor (compound 14) was diluted in DMSO at a stock concentration of 100 mM, as previously described [8]. All drugs used in the study were then diluted in the culture media to the final concentrations used in various assays [7,8].…”

“…The Gα i 2 inhibitor (compound 14) was diluted in DMSO at a stock concentration of 100 mM, as previously described [8]. All drugs used in the study were then diluted in the culture media to the final concentrations used in various assays [7,8]. To determine the effects of specific treatments on the levels of Gα i 2 protein, LNCaP and PC3 cells (10 6 cells) were cultured overnight in 10 cm 2 culture dishes.…”

“…This novel effect of Gα i 2 does not require activation by GPCRs, and it is downstream or independent of PI3-kinase and Rac1 activation [7]. Since Gα i 2 plays an essential role in cancer cell migration and invasion, we have synthesized a cohort of small molecule inhibitors which blocks the activation of the Gα i 2 protein, leading to the inhibition of cell migration and invasion in several cancer types [8].…”