Nucleoplasmic calcium regulates cell proliferation through legumain
Viviane Andrade1, Mateus Guerra2, Camila Jardim3
1Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
Journal of Hepatology
|January 18, 2011
Summary
Nuclear calcium (Ca2+) regulates liver cell growth. Researchers identified asparaginyl endopeptidase legumain (LGMN) as a key protein, finding its altered expression impacts cell proliferation and may contribute to liver cancer.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Nucleoplasmic calcium (Ca2+) plays a role in regulating liver cell growth.
- The specific proteins mediating this regulation remain largely unknown.
Purpose of the Study:
- To identify proteins regulated by nucleoplasmic Ca2+ that influence liver cell proliferation.
- To elucidate the role of these proteins in liver carcinogenesis.
Main Methods:
- Utilized Rapid Subtraction Hybridization (RaSH) in SKHep1 liver cells to compare gene expression profiles.
- Manipulated nuclear Ca2+ buffering using parvalbumin (PV) variants.
- Employed siRNA for gene knockdown and assessed cell proliferation via BrdU uptake and mitotic index.
Main Results:
- Identified asparaginyl endopeptidase legumain (LGMN) as a Ca2+-sensitive gene.
- Decreased nuclear Ca2+ significantly reduced LGMN mRNA and protein levels.
- LGMN knockdown inhibited SKHep1 cell proliferation and altered cell cycle progression (G2/M phase).
- LGMN expression was elevated in hepatocellular carcinoma (HCC) tissues.
Conclusions:
- Nuclear Ca2+ signaling regulates cell proliferation, partly through modulating LGMN expression.
- Increased LGMN expression is implicated in liver carcinogenesis and may serve as a potential biomarker.
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