Related Experiment Videos
[Ca2+]i as a potential downregulator of alpha2beta1-integrin-mediated A2058 tumor cell migration to type IV collagen
1Department of Bioengineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Abstract:
We have investigated cellular Ca2+ regulation during A2058 human melanoma cell chemotaxis to type IV collagen (CIV). We have identified alpha2beta1-integrin as the primary mediator of A2058 cell response to CIV in vitro. Integrin ligation initiated a characteristic intracellular Ca2+ concentration ([Ca2+]i) response consisting of an internal release and a receptor-mediated Ca2+ entry. Thapsigargin (TG) pretreatment drained overlapping and CIV-inducible internal Ca2+ stores while initiating a store-operated Ca2+ release (SOCR). CIV-mediated Ca2+ entry was additive to TG-SOCR, suggesting an independent signaling mechanism. Similarly, ionophore application in a basal medium containing Ca2+ initiated a sustained influx. Elevated [Ca2+]i from TG-SOCR or ionophore significantly attenuated cell migration to CIV by recruiting the Ca2+/calcineurin-mediated signaling pathway. Furthermore, low [Ca2+]i induced by EGTA application in the presence of ionophore fully restored cell motility to CIV. Together, these results suggest that [Ca2+]i signaling accompanying A2058 cell response to alpha2beta1-integrin ligation is neither necessary nor sufficient and that elevated [Ca2+]i downregulates cell motility via a calcineurin-mediated mechanism in A2058 cell chemotaxis to CIV.
Insights
Cellular calcium regulation impacts melanoma cell movement. Elevated calcium levels, triggered by alpha2beta1-integrin and type IV collagen, inhibit A2058 cell migration via calcineurin signaling.
Area of Science:
- Cell Biology
- Biochemistry
- Cancer Research
Background:
- Melanoma cell migration is crucial for metastasis.
- Understanding cellular calcium regulation is key to controlling cell motility.
- Type IV collagen (CIV) and alpha2beta1-integrin play roles in cell adhesion and migration.
Purpose of the Study:
- To investigate the role of intracellular calcium concentration ([Ca2+]i) in A2058 human melanoma cell chemotaxis to type IV collagen (CIV).
- To identify the specific integrin mediating the response to CIV.
- To elucidate the signaling pathways involved in calcium regulation during cell migration.
Main Methods:
- Investigated cellular Ca2+ regulation using A2058 melanoma cells.
- Utilized alpha2beta1-integrin as the primary mediator for response to CIV.
- Employed thapsigargin (TG) to deplete internal Ca2+ stores and induce store-operated Ca2+ release (SOCR).
- Assessed the impact of elevated [Ca2+]i on cell migration using EGTA and ionophore.
Main Results:
- Identified alpha2beta1-integrin as the key mediator of A2058 cell response to CIV.
- Observed that integrin ligation triggers a Ca2+ response involving internal release and receptor-mediated entry.
- Found that elevated [Ca2+]i, induced by TG-SOCR or ionophore, significantly attenuated cell migration.
- Demonstrated that low [Ca2+]i restored cell motility, implicating calcineurin signaling.
Conclusions:
- [Ca2+]i signaling is not essential for A2058 cell chemotaxis to CIV.
- Elevated [Ca2+]i downregulates melanoma cell motility through a calcineurin-mediated pathway.
- Targeting calcium signaling could offer therapeutic strategies for melanoma metastasis.