Related Experiment Video
Updated: Jun 16, 2026
05:06
Tumor Allotransplantation in Drosophila melanogaster with a Programmable Auto-Nanoliter Injector
Published on: February 2, 2021
Tumor suppressor HLJ1 binds and functionally alters nucleophosmin via activating enhancer binding protein 2alpha
Tzu-Pei Chang1, Sung-Liang Yu, Sheng-Yi Lin
1Institutes of Biomedical Sciences and Molecular Biology, National Chung Hsing University, Taiwan 40227,ROC.
Cancer Research
|February 11, 2010
Summary
Heat shock protein 40 (HLJ1) interacts with nucleophosmin (NPM1), altering its oligomerization. This interaction influences non-small cell lung cancer cell migration and invasiveness, revealing a novel mechanism of tumor suppression.
Area of Science:
- Oncology
- Molecular Biology
- Cell Biology
Background:
- Heat shock protein 40 (HLJ1) is a tumor suppressor implicated in non-small cell lung cancer (NSCLC) tumorigenesis and metastasis.
- The precise mechanism by which HLJ1 exerts its tumor-suppressive functions remains largely unknown.
Purpose of the Study:
- To elucidate the molecular mechanism of HLJ1 action in NSCLC.
- To investigate the interaction between HLJ1 and nucleophosmin (NPM1) and its functional consequences.
Main Methods:
- Co-immunoprecipitation to demonstrate HLJ1-NPM1 interaction.
- Overexpression and silencing studies to assess the impact on NPM1 oligomerization, STAT3 activity, and cellular functions.
- Analysis of transcription corepressor AP-2alpha and matrix metalloproteinase-2 (MMP-2) activity.
Main Results:
- HLJ1 specifically interacts with NPM1, forming a multiprotein complex that modulates NPM1's nucleolar distribution and oligomerization state.
- Overexpression of NPM1 oligomers in HLJ1-high cells enhanced STAT3 activity, migration, invasiveness, and colony formation.
- Silencing HLJ1 accelerated NPM1 oligomerization, inhibited AP-2alpha activity, and increased MMP-2 and STAT3 activities.
Conclusions:
- HLJ1 modulates NPM1 oligomerization through HLJ1-NPM1 heterodimer formation, thereby influencing NPM1's dual role as a tumor suppressor or oncogene.
- HLJ1 recruits AP-2alpha to the MMP-2 promoter, contributing to its proposed tumor-suppressive mechanism in NSCLC.
Related Concept Videos
02:23Abnormal 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...
01:12Loss of Tumor Suppressor Gene Functions
Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
01:12Loss of Tumor Suppressor Gene Functions
Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
01:05Cancer-Critical Genes II: Tumor Suppressor Genes
Genes usually encode proteins necessary for the proper functioning of a healthy cell. Mutations can often cause changes to the gene expression pattern, thereby altering the phenotype.
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
01:05Cancer-Critical Genes II: Tumor Suppressor Genes
Genes usually encode proteins necessary for the proper functioning of a healthy cell. Mutations can often cause changes to the gene expression pattern, thereby altering the phenotype.
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
02:39lncRNA - Long Non-coding RNAs
In humans, more than 80% of the genome gets transcribed. However, only around 2% of the genome codes for proteins. The remaining part produces non-coding RNAs which includes ribosomal RNAs, transfer RNAs, telomerase RNAs, and regulatory RNAs, among other types. A large number of regulatory non-coding RNAs have been classified into two groups depending upon their length – small non-coding RNAs, such as microRNA, which are less than 200 nucleotides in length, and long non-coding RNA (lncRNA)...