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Evaluating Inhibition of the Epidermal Growth Factor (EGF)-Induced Response of Mutant MCF10A Cells with an Acoustic Sensor.

Garcia MP, Shahid A, Chen JY, Xi J - Biosensors (Basel) (2012)

Bottom Line: Using immunofluorescence imaging, we have also verified the quantitative relationship between the ΔD-response (change in energy dissipation factor) and the level of focal adhesions quantified with the areal density of immunostained vinculin under those inhibitory conditions.Such a correlation suggests that the dynamic restructuring of focal adhesions can be assessed based on the time-dependent change in ΔD-response.Overall, this report has shown that the QCM-D has the potential to become an effective sensing platform for screening therapeutic agents that target signaling and cytoskeletal proteins.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA. mpg36@drexel.edu.

ABSTRACT
Many cancer treatments rely on inhibition of epidermal growth factor (EGF)-induced cellular responses. Evaluating drug effects on such responses becomes critical to the development of new cancer therapeutics. In this report, we have employed a label-free acoustic sensor, the quartz crystal microbalance with dissipation monitoring (QCM-D), to track the EGF-induced response of mutant MCF10A cells under various inhibitory conditions. We have identified a complex cell de-adhesion process, which can be distinctly altered by inhibitors of signaling pathways and cytoskeleton formation in a dose-dependent manner. The dose dependencies of the inhibitors provide IC50 values which are in strong agreement with the values reported in the literature, demonstrating the sensitivity and reliability of the QCM-D as a screening tool. Using immunofluorescence imaging, we have also verified the quantitative relationship between the ΔD-response (change in energy dissipation factor) and the level of focal adhesions quantified with the areal density of immunostained vinculin under those inhibitory conditions. Such a correlation suggests that the dynamic restructuring of focal adhesions can be assessed based on the time-dependent change in ΔD-response. Overall, this report has shown that the QCM-D has the potential to become an effective sensing platform for screening therapeutic agents that target signaling and cytoskeletal proteins.

No MeSH data available.


Related in: MedlinePlus

The amplitudes of EGF-induced ΔD-responsesat 40 min as a function of inhibitor concentrations.The amplitude is defined as the absolute value of the difference between the experimental value and the control value. The data, derived from the average of at least three sets of independent data, was fit with the dose-response function. The resulting IC50 values are also listed in Table 1. (A) PD158780. IC50 = 64 ± 30 nM. (B) cytochalasin D. IC50 = 0.18 ± 0.11 µM. (C) L779450. IC50 = 1.0 ± 0.6 µM. (D) LY294002. IC50 = 1.1 ± 0.5 µM. (E) U73122. IC50 = 2.5 ± 0.9 µM.
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biosensors-02-00448-f004: The amplitudes of EGF-induced ΔD-responsesat 40 min as a function of inhibitor concentrations.The amplitude is defined as the absolute value of the difference between the experimental value and the control value. The data, derived from the average of at least three sets of independent data, was fit with the dose-response function. The resulting IC50 values are also listed in Table 1. (A) PD158780. IC50 = 64 ± 30 nM. (B) cytochalasin D. IC50 = 0.18 ± 0.11 µM. (C) L779450. IC50 = 1.0 ± 0.6 µM. (D) LY294002. IC50 = 1.1 ± 0.5 µM. (E) U73122. IC50 = 2.5 ± 0.9 µM.

Mentions: The IC50 value for each inhibitor was derived based on its dose dependence determined by fitting the amplitudes of the ΔD-response values at 40 min as a function of the inhibitor concentrations (Figure 4). These values obtained from the QCM-D measurements along with the values reported in the literature are listed in Table 1. The reported IC50 value for cytochalasin D was determined based on its inhibitory effect on the mechanical properties of the cell sample [69]. All other values were determined based on the in vivo inhibitory effects on the target enzymes in cell samples [62,70,71,72]. It is apparent that the experimental values are in strong agreement with the reported values (Table 1), which strongly supports the notion that the QCM-D has the sensitivity and reliability to be potentially utilized as a sensing platform for drug screening. To achieve this goal, increasing the throughput capacity of the QCM-D would be the next critical step. In addition, establishing the technical advantage of the QCM-D compared to other sensor technologies would also be important.


Evaluating Inhibition of the Epidermal Growth Factor (EGF)-Induced Response of Mutant MCF10A Cells with an Acoustic Sensor.

Garcia MP, Shahid A, Chen JY, Xi J - Biosensors (Basel) (2012)

The amplitudes of EGF-induced ΔD-responsesat 40 min as a function of inhibitor concentrations.The amplitude is defined as the absolute value of the difference between the experimental value and the control value. The data, derived from the average of at least three sets of independent data, was fit with the dose-response function. The resulting IC50 values are also listed in Table 1. (A) PD158780. IC50 = 64 ± 30 nM. (B) cytochalasin D. IC50 = 0.18 ± 0.11 µM. (C) L779450. IC50 = 1.0 ± 0.6 µM. (D) LY294002. IC50 = 1.1 ± 0.5 µM. (E) U73122. IC50 = 2.5 ± 0.9 µM.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263556&req=5

biosensors-02-00448-f004: The amplitudes of EGF-induced ΔD-responsesat 40 min as a function of inhibitor concentrations.The amplitude is defined as the absolute value of the difference between the experimental value and the control value. The data, derived from the average of at least three sets of independent data, was fit with the dose-response function. The resulting IC50 values are also listed in Table 1. (A) PD158780. IC50 = 64 ± 30 nM. (B) cytochalasin D. IC50 = 0.18 ± 0.11 µM. (C) L779450. IC50 = 1.0 ± 0.6 µM. (D) LY294002. IC50 = 1.1 ± 0.5 µM. (E) U73122. IC50 = 2.5 ± 0.9 µM.
Mentions: The IC50 value for each inhibitor was derived based on its dose dependence determined by fitting the amplitudes of the ΔD-response values at 40 min as a function of the inhibitor concentrations (Figure 4). These values obtained from the QCM-D measurements along with the values reported in the literature are listed in Table 1. The reported IC50 value for cytochalasin D was determined based on its inhibitory effect on the mechanical properties of the cell sample [69]. All other values were determined based on the in vivo inhibitory effects on the target enzymes in cell samples [62,70,71,72]. It is apparent that the experimental values are in strong agreement with the reported values (Table 1), which strongly supports the notion that the QCM-D has the sensitivity and reliability to be potentially utilized as a sensing platform for drug screening. To achieve this goal, increasing the throughput capacity of the QCM-D would be the next critical step. In addition, establishing the technical advantage of the QCM-D compared to other sensor technologies would also be important.

Bottom Line: Using immunofluorescence imaging, we have also verified the quantitative relationship between the ΔD-response (change in energy dissipation factor) and the level of focal adhesions quantified with the areal density of immunostained vinculin under those inhibitory conditions.Such a correlation suggests that the dynamic restructuring of focal adhesions can be assessed based on the time-dependent change in ΔD-response.Overall, this report has shown that the QCM-D has the potential to become an effective sensing platform for screening therapeutic agents that target signaling and cytoskeletal proteins.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA. mpg36@drexel.edu.

ABSTRACT
Many cancer treatments rely on inhibition of epidermal growth factor (EGF)-induced cellular responses. Evaluating drug effects on such responses becomes critical to the development of new cancer therapeutics. In this report, we have employed a label-free acoustic sensor, the quartz crystal microbalance with dissipation monitoring (QCM-D), to track the EGF-induced response of mutant MCF10A cells under various inhibitory conditions. We have identified a complex cell de-adhesion process, which can be distinctly altered by inhibitors of signaling pathways and cytoskeleton formation in a dose-dependent manner. The dose dependencies of the inhibitors provide IC50 values which are in strong agreement with the values reported in the literature, demonstrating the sensitivity and reliability of the QCM-D as a screening tool. Using immunofluorescence imaging, we have also verified the quantitative relationship between the ΔD-response (change in energy dissipation factor) and the level of focal adhesions quantified with the areal density of immunostained vinculin under those inhibitory conditions. Such a correlation suggests that the dynamic restructuring of focal adhesions can be assessed based on the time-dependent change in ΔD-response. Overall, this report has shown that the QCM-D has the potential to become an effective sensing platform for screening therapeutic agents that target signaling and cytoskeletal proteins.

No MeSH data available.


Related in: MedlinePlus