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Updated: Sep 27, 2025
Author Spotlight: Establishing a Murine Non-Small Cell Lung Cancer Model for Developing Nanoformulations of Anticancer Drugs
Published on: May 10, 2024
Noninvasive Evaluation of Multidrug Resistance via Imaging of ABCG2/BCRP Multidrug Transporter in Lung Cancer
Cuicui Li1,2, Qi Yang2, Zhao Chen2
1Department of Nuclear Medicine, Capital Medical University Affiliated Beijing Friendship Hospital, Beijing 100050, China.
Abstract:
Chemotherapy is an important method for the treatment of lung cancer, but multidrug resistance (MDR) greatly reduces the efficacy. The superfamily of ATP-binding cassette (ABC) transport proteins is related to MDR. As a subfamily of ABC proteins, ABCG2/BCRP (breast cancer resistance protein, BCRP) is considered a major player in the development of cancer MDR. For the stratification of chemotherapeutic choices, we constructed Cy5.5- or 89Zr-labeled ABCG2-targeted monoclonal antibody (mAb) ABCG2-PKU1 for noninvasive evaluation of ABCG2 expression in lung cancer xenograft models. ABCG2 expression was screened in H460/MX (mitoxantrone resistant), H460, and H1299 human lung cancer cell lines using Western blotting. ELISA, flow cytometry, and cell immunofluorescent staining were used to evaluate the binding ability of ABCG2-PKU1 to ABCG2 antigen. Lung cancer murine xenograft models were built for in vivo experiments. ABCG2-PKU1 was labeled with Cy5.5 (Cy5.5-ABCG2) for fluorescent imaging and radiolabeled with 89Zr (89Zr-DFO-ABCG2) for immunoPET imaging following the conjugation with p-SCN-deferoxamine (DFO). In vivo imaging was performed in lung cancer models at 2, 24, 48, 72, 96, 120, 144, and 168 h postinjection. Ex vivo biodistribution was conducted after the terminal time point of imaging. Finally, tissue immunohistochemical staining was used to evaluate the tumor expression of ABCG2. Western blotting showed that the H460/MX cells had a high ABCG2 expression level whereas H460 and H1299 had moderate and low levels. ELISA, flow cytometry, and cell immunofluorescent staining results validated the good binding affinity between ABCG2-PKU1 and ABCG2. The H460/MX and H460 cells were used to build positive lung cancer models, and H1299 cells were used to build negative models. The fluorescent imaging showed that the tumor average radiant efficiency of Cy5.5-ABCG2 reached the maximum at 72 and 120 h in H460/MX and H460 respectively (n = 3, P < 0.01). The tumor uptake of Cy5.5-ABCG2 in H1299 (n = 3) was significantly lower than H460/MX and H460 (P < 0.01). ImmunoPET imaging showed that the tumor uptake of 89Zr-DFO-ABCG2 in H460/MX was significantly higher than H460, with a maximum of 4.15 ± 0.41 %ID/g and 2.81 ± 0.24 %ID/g at 168 and 144 h, respectively (n = 5, P < 0.01). The H1299 tumors showed significantly lower uptake than H460/MX and H460 (n = 5, P < 0.01). The radioactive uptake of 89Zr-DFO-ABCG2 among three groups in the heart, liver, and kidney gradually decreased over time. Ex vivo biodistribution verified the differential tumor uptake among the three groups (P < 0.01). Immunohistochemical staining revealed that the H460/MX tumor had the highest expression of ABCG2, whereas H460 and H1299 had the moderate and lowest expression, respectively. Therefore, in this study, fluorescent and immunoPET imaging of lung cancer MDR models using Cy5.5-ABCG2 and 89Zr-DFO-ABCG2 noninvasively evaluated the differential expression of ABCG2, which are expected to be used for the diagnosis and the selection for clinical treatment options for lung cancer MDR patients in future applications.
Insights
This study developed novel Cy5.5- and 89Zr-labeled antibodies to noninvasively assess ABCG2 expression in lung cancer. These imaging agents successfully differentiated lung cancer models with varying ABCG2 levels, aiding potential treatment selection.
Area of Science:
- Oncology
- Biomedical Imaging
- Molecular Biology
Background:
- Multidrug resistance (MDR) significantly limits chemotherapy efficacy in lung cancer.
- ATP-binding cassette (ABC) transporters, particularly ABCG2/BCRP, are key contributors to cancer MDR.
- Accurate assessment of ABCG2 expression is crucial for stratifying lung cancer treatment options.
Purpose of the Study:
- To develop and evaluate novel ABCG2-targeted imaging agents for noninvasive assessment of ABCG2 expression in lung cancer models.
- To investigate the utility of Cy5.5-labeled and 89Zr-labeled monoclonal antibody ABCG2-PKU1 for fluorescent and immunoPET imaging, respectively.
- To correlate imaging findings with ABCG2 expression levels in lung cancer xenografts.
Main Methods:
- Western blotting was used to determine ABCG2 expression levels in human lung cancer cell lines (H460/MX, H460, H1299).
- ELISA, flow cytometry, and immunofluorescence confirmed the binding affinity of ABCG2-PKU1 to the ABCG2 antigen.
- Lung cancer murine xenograft models were established and imaged using Cy5.5-ABCG2 (fluorescent imaging) and 89Zr-DFO-ABCG2 (immunoPET imaging).
- In vivo imaging, ex vivo biodistribution, and immunohistochemical staining were performed to evaluate agent performance and ABCG2 expression.
Main Results:
- Western blotting confirmed varying ABCG2 expression levels across cell lines, with H460/MX showing the highest.
- In vivo fluorescent imaging demonstrated differential tumor uptake of Cy5.5-ABCG2, correlating with ABCG2 expression.
- ImmunoPET imaging revealed significantly higher tumor uptake of 89Zr-DFO-ABCG2 in models with high ABCG2 expression (H460/MX) compared to those with lower expression (H460, H1299).
- Ex vivo biodistribution and immunohistochemistry validated the noninvasive imaging results, confirming differential ABCG2 expression in tumors.
Conclusions:
- Cy5.5-ABCG2 and 89Zr-DFO-ABCG2 are effective tools for noninvasively evaluating differential ABCG2 expression in lung cancer models.
- These targeted imaging agents show promise for diagnosing lung cancer MDR and guiding clinical treatment selection.
- The developed imaging probes offer a potential strategy for personalized medicine in lung cancer treatment.
