Related Experiment Video
Updated: May 8, 2026
Quantifying Antibody-Dependent Cellular Cytotoxicity in a Tumor Spheroid Model: Application for Drug Discovery
Published on: April 26, 2024
[Annexin A1 increases the sensitivity of K562 cell to imatinib]
Kang-Ning Li1, Jing Jin, Xiao-Guang Chen
1State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
Abstract:
Annexin A1 (ANXA1) is a kind of endogenous scaffold protein. Previous research showed that ANXA1 could increase markedly with multiple increase of drug resistance in K562/imatinib cell lines in vitro. Here the stable transfection cell strains K562-pEGFP-N1 which was the native control and K562-pEGFP-N1-ANXA1 which can stably express ANXA1 were established using the Lipofectamine 2000 in order to find whether ANXA1 involved in the drug resistance. Cell growth inhibition experiment via MTT and cell proliferation experiment via MTS showed that K562-pEGFP-N1-ANXA1 cell strain was more sensitive to imatinib than the K562-pEGFP-N1 cell strain, and however the ability of proliferation of K562-pEGFP-N1-ANXA1 cell strain did not change compared with the negative control. Western blotting results showed that the expression of proteins in Annexin family did not change; drug resistance proteins, Bcr-Abl/p-Bcr-Abl (Tyr245), Src family kinase for example, did not change; proteins related with cell proliferation and cell cycle, such as ERK1/2MAPK, p-38MAPK, CDK1 and Wee 1, did not change either in the K562-pEGFP-N1-ANXA1 cell strain compared with the negative control. The co-immunoprecipitation result showed that the interaction between ANXA1 and beta-actin in the K562-pEGFP-N1-ANXA1 cell strain increased markedly. The deduction was that ANXA1 may make the K562-pEGFP-N1-ANXA1 cell strain more sensitive to imatinib due to the increased uptake of imatinib via the increase of ANXA1 and the interaction between ANXA1 and beta-actin in the K562-pEGFP-N1-ANXA1 cell strain in vitro.
Insights
Annexin A1 (ANXA1) enhances imatinib sensitivity in K562 cells by increasing drug uptake, despite not altering proliferation or known resistance pathways. This suggests ANXA1 plays a role in modulating drug response through interactions with beta-actin.
Area of Science:
- Molecular Biology
- Cancer Research
- Pharmacology
Background:
- Annexin A1 (ANXA1) is an endogenous scaffold protein implicated in cellular processes.
- Previous studies indicated a correlation between elevated ANXA1 levels and increased drug resistance in K562/imatinib cell lines.
- The precise role of ANXA1 in modulating imatinib drug resistance remains to be fully elucidated.
Purpose of the Study:
- To investigate the involvement of Annexin A1 (ANXA1) in the drug resistance of K562/imatinib cell lines.
- To determine the effect of stable ANXA1 expression on imatinib sensitivity and cellular proliferation.
- To explore potential molecular mechanisms underlying ANXA1's influence on imatinib response.
Main Methods:
- Establishment of stable transfection cell strains: K562-pEGFP-N1 (control) and K562-pEGFP-N1-ANXA1 (ANXA1-expressing) using Lipofectamine 2000.
- Assessment of cell sensitivity and proliferation using MTT and MTS assays.
- Analysis of protein expression levels via Western blotting and protein interactions using co-immunoprecipitation.
Main Results:
- K562-pEGFP-N1-ANXA1 cells exhibited increased sensitivity to imatinib compared to control cells, without significant changes in proliferation.
- Expression levels of Annexin family proteins, key drug resistance proteins (Bcr-Abl/p-Bcr-Abl, Src family kinase), and cell cycle regulators (ERK1/2MAPK, p-38MAPK, CDK1, Wee 1) remained unchanged.
- A marked increase in the interaction between ANXA1 and beta-actin was observed in ANXA1-expressing cells.
Conclusions:
- Annexin A1 (ANXA1) expression enhances imatinib sensitivity in K562 cells.
- The heightened sensitivity is likely mediated by increased imatinib uptake, potentially facilitated by ANXA1 and its interaction with beta-actin.
- ANXA1 does not appear to influence imatinib resistance through alterations in major drug resistance or cell cycle regulatory proteins.
