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Updated: Sep 3, 2025
A Method for Screening and Validation of Resistant Mutations Against Kinase Inhibitors
Published on: December 7, 2014
Integrin Signaling Shaping BTK-Inhibitor Resistance
Laura Polcik1,2, Svenja Dannewitz Prosseda1, Federico Pozzo3
1Department of Internal Medicine I, Faculty of Medicine and Medical Center, University of Freiburg, 79106 Freiburg, Germany.
Abstract:
Integrins are adhesion molecules that function as anchors in retaining tumor cells in supportive tissues and facilitating metastasis. Beta1 integrins are known to contribute to cell adhesion-mediated drug resistance in cancer. Very late antigen-4 (VLA-4), a CD49d/CD29 heterodimer, is a beta1 integrin implicated in therapy resistance in both solid tumors and haematological malignancies such as chronic lymphocytic leukemia (CLL). A complex inside-out signaling mechanism activates VLA-4, which might include several therapeutic targets for CLL. Treatment regimens for this disease have recently shifted towards novel agents targeting BCR signaling. Bruton's tyrosine kinase (BTK) is a component of B cell receptor signaling and BTK inhibitors such as ibrutinib are highly successful; however, their limitations include indefinite drug administration, the development of therapy resistance, and toxicities. VLA-4 might be activated independently of BTK, resulting in an ongoing interaction of CD49d-expressing leukemic cells with their surrounding tissue, which may reduce the success of therapy with BTK inhibitors and increases the need for alternative therapies. In this context, we discuss the inside-out signaling cascade culminating in VLA-4 activation, consider the advantages and disadvantages of BTK inhibitors in CLL and elucidate the mechanisms behind cell adhesion-mediated drug resistance.
Insights
Very late antigen-4 (VLA-4) integrin activation may drive cancer drug resistance independently of Bruton's tyrosine kinase (BTK) signaling in chronic lymphocytic leukemia (CLL). This highlights VLA-4 as a potential therapeutic target for overcoming BTK inhibitor resistance.
Area of Science:
- Oncology
- Cell Biology
- Immunology
Background:
- Integrins, like beta1 integrins, are crucial for tumor cell adhesion and metastasis.
- Very late antigen-4 (VLA-4), a beta1 integrin, is implicated in therapy resistance in various cancers, including chronic lymphocytic leukemia (CLL).
- Cell adhesion-mediated drug resistance is a significant challenge in cancer treatment.
Purpose of the Study:
- To explore the role of VLA-4 inside-out signaling in cancer therapy resistance.
- To discuss the implications of VLA-4 activation in the context of Bruton's tyrosine kinase (BTK) inhibitors for CLL treatment.
- To elucidate the mechanisms of cell adhesion-mediated drug resistance.
Main Methods:
- Review of current literature on integrin signaling, VLA-4 function, and BTK inhibitors in CLL.
- Analysis of VLA-4 activation pathways and their relationship with BTK signaling.
- Discussion of therapeutic strategies targeting VLA-4 and cell adhesion-mediated drug resistance.
Main Results:
- VLA-4 activation is a complex process involving inside-out signaling pathways.
- VLA-4 can be activated independently of BTK signaling, potentially contributing to resistance against BTK inhibitors.
- Cell adhesion mediated by VLA-4 may protect leukemic cells from therapy.
Conclusions:
- VLA-4 represents a potential therapeutic target for overcoming resistance to BTK inhibitors in CLL.
- Understanding VLA-4 signaling is critical for developing alternative or combination therapies for resistant CLL.
- Targeting cell adhesion mechanisms could enhance the efficacy of cancer treatments.
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