Related Experiment Videos

Effect of Sirpalpha1 on the expression of nuclear factor-kappa B in hepatocellular carcinoma

Jian-Min Qin1, Xing-Wang Wan, Jin-Zhang Zeng

  • 1Department of Hepatobiliary and Pancreatic Surgery, Beijing Chaoyang Hospital, Capital University of Medical Sciences, Beijing 100020, China. jianminqin@yahoo.com

Hepatobiliary & Pancreatic Diseases International : HBPD INT
|June 6, 2007
PubMed
Abstract

Insights

Signal regulatory protein alpha1 (Sirpalpha1) inhibits liver cancer cell proliferation by modulating nuclear factor-kappa B (NF-κB) pathway components. This study clarifies Sirpalpha1

Area of Science:

  • Molecular Biology
  • Cancer Research
  • Cell Signaling

Background:

  • Signal regulatory protein alpha1 (Sirpalpha1) negatively regulates receptor tyrosine kinase (RTK)-dependent proliferation.
  • Sirpalpha1 is associated with hepatocellular carcinoma (HCC) occurrence and liver regeneration.
  • Mechanisms of Sirpalpha1's role in HCC require further elucidation.

Purpose of the Study:

  • To investigate the regulatory mechanisms of Sirpalpha1 in HCC development.
  • To clarify how Sirpalpha1 influences cell proliferation signaling pathways.
  • To establish a transfected cell line for mechanistic studies.

Main Methods:

  • Transfection of Sk-Hep1 liver cancer cells with Sirpalpha1 and mutant plasmids.
  • Screening of transfected cells using G418.
  • Western blotting to assess protein expression (P65, P50, IkappaBalpha, cyclin D1, Fas).
  • Immunofluorescence to determine P65 and P50 localization.

Main Results:

  • Sirpalpha1 upregulated IkappaBalpha expression in Sk-Hep1 cells.
  • Sirpalpha1 downregulated P65, P50, and cyclin D1 expression.
  • Sirpalpha1 influenced P65 and P50 localization between cytoplasm and nucleus.

Conclusions:

  • Sirpalpha1 negatively regulates HCC cell proliferation by affecting NF-κB pathway.
  • Modulation of NF-κB protein content and localization by Sirpalpha1 impacts cyclin D1 expression.
  • This mechanism is crucial for Sirpalpha1's role in inhibiting HCC carcinogenesis and development.

Related Concept Videos

NF-κB-dependent Signaling Pathway02:26

NF-κB-dependent Signaling Pathway

The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The heterodimer of NF-κB...
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
Co-activators and Co-repressors02:04

Co-activators and Co-repressors

Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
NF-kB-dependent Signaling Pathway02:26

NF-kB-dependent Signaling Pathway

The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The heterodimer of NF-κB...
Cell Specific Gene Expression01:58

Cell Specific Gene Expression

Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...