Akt Downregulates B-Cell Translocation Gene-2 Expression Via Erk1/2 Inhibition for Proliferation of Cancer Cells

Area of Science:

• Molecular Biology
• Cancer Research
• Cell Signaling

Background:

• B-cell translocation gene 2 (Btg2) functions as a tumor suppressor gene involved in various biological processes.
• Akt, a serine/threonine kinase, is recognized as an oncogene, but its prognostic value and interaction with tumor suppressor genes require further investigation.

Purpose of the Study:

• To investigate the Akt-mediated downregulation of Btg2 and its impact on cancer cell proliferation and survival.
• To elucidate the molecular mechanisms underlying Btg2 regulation by Akt signaling.

Main Methods:

• Utilized human leukemia (HL-60, THP-1) and colon cancer (DLD-1) cell lines.
• Pharmacological inhibition of Akt using LY294002 and activation using insulin.
• Inhibition of MAPK kinase with U0126.
• Assessed Btg2 mRNA expression, Erk1/2 activation, cell proliferation, and cell viability.
• Investigated the effects of exogenous Btg2 expression on cell cycle progression.

Main Results:

• Akt inhibition (LY294002) increased Btg2 mRNA expression and Erk1/2 activation, while decreasing cell proliferation and viability.
• Akt activation (insulin) decreased Btg2 expression and enhanced cell survival and division.
• MAPK kinase inhibition (U0126) abrogated Btg2 expression.
• Exogenous Btg2 expression reduced proliferation and induced G1 cell cycle arrest.

Conclusions:

• Akt negatively regulates Btg2 expression, likely through Erk1/2 signaling, thereby promoting cancer cell survival and proliferation.
• This study reveals a novel mechanism of Akt-mediated tumorgenicity through the regulation of the tumor suppressor Btg2.