Quantification of the Synergism Between HER-Targeted Drugs with Human Blood Serum and EGF
D E Kamashev1,2, E M Leboshchina3, A V Koleboshina1
1Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997 Russia.
Abstract:
Finding the optimal combination of drugs for the effective inhibition of cancer cell growth is an extremely important task today, as the number of such drugs continues to grow. There are several approaches to determining the nature of drug interactions, allowing one to establish whether they are additive, synergis tic, or antagonistic. One such approach is described here, and it is demonstrated how to quantitatively meas ure the degree of interaction between two drugs. It is shown that human peripheral blood serum and EGF modulate the activity of HER2-targeted drugs in inhibiting the proliferation of HER2-positive BT474 and SK-BR-3 cells. We compared the effect of blood serum samples from breast cancer (BC) patients and healthy donors on the action of trastuzumab. Using the proposed method, it is possible to calculate the Combination Index (CI). For 17 serum samples from healthy donors, the mean CI was 0.396, while for 19 serum samples from patients with BC, the mean CI was 0.214. These results indicate a synergistic interaction between tras tuzumab and blood serum in both groups. We also found significant differences in CI values between healthy donors and breast cancer patients: blood serum samples from patients enhance the effect of trastuzumab to a greater extent.
Insights
Breast cancer patients' blood serum enhances the effectiveness of trastuzumab, a HER2-targeted drug, more than healthy donors' serum. This indicates a synergistic drug interaction, crucial for developing effective cancer therapies.
Area of Science:
- Pharmacology and Oncology
- Biochemistry and Molecular Biology
Background:
- Optimizing drug combinations for cancer cell growth inhibition is critical due to the expanding number of available drugs.
- Understanding drug interactions (additive, synergistic, antagonistic) is essential for effective cancer treatment strategies.
Purpose of the Study:
- To quantitatively measure the degree of interaction between HER2-targeted drugs and human serum.
- To investigate the modulatory effects of human peripheral blood serum and EGF on HER2-targeted drug activity in HER2-positive cells.
- To compare the impact of serum from breast cancer patients versus healthy donors on trastuzumab efficacy.
Main Methods:
- Development and application of a quantitative method to measure drug interaction degrees.
- Calculation of the Combination Index (CI) to assess drug synergy.
- Inhibition of proliferation assays using HER2-positive cell lines (BT474 and SK-BR-3) treated with trastuzumab and varying serum samples.
Main Results:
- Human peripheral blood serum and EGF were found to modulate the activity of HER2-targeted drugs.
- A synergistic interaction between trastuzumab and blood serum was observed in both healthy donors (mean CI=0.396) and breast cancer patients (mean CI=0.214).
- Blood serum from breast cancer patients significantly enhanced the effect of trastuzumab compared to serum from healthy donors.
Conclusions:
- The proposed method allows for the quantitative measurement of drug interactions, specifically the Combination Index (CI).
- Breast cancer patient serum exhibits a stronger synergistic effect with trastuzumab than serum from healthy individuals.
- These findings highlight the potential of using patient-specific serum components to predict or enhance HER2-targeted therapy response.
