Application of a CYP1B1-Targeted NIR Probe for Breast Cancer Diagnosis, Surgical Navigation, and CYP1B1-Associated Chemotherapy Resistance Monitoring

Early detection and precise treatment for breast cancer are crucial, given its high global incidence rate. Hence, the development of novel imaging targets is essential for diagnosing and monitoring resistance to chemotherapy, which is pivotal for achieving precise and personalized treatment for breast cancer patients. In our previous work, we successfully developed a near-infrared (NIR) probe 1 for CYP1B1-targeted imaging. In this study, we aimed to investigate the utility of the probe as a NIR fluorescence and photoacoustic dual-mode imaging probe for the detection and surveillance of breast cancer. Western blotting of cancer cell lines has confirmed that CYP1B1 is widely expressed in breast cancer and gynecological cancer. In vitro NIR fluorescence imaging capability of the probe for tracking CYP1B1-positive tumor cells was validated by using confocal microscopy. Further studies, including in vivo fluorescence and photoacoustic dual-model imaging and ex vivo biological distribution analysis on a triple-negative breast cancer xenograft mouse model, demonstrated that the probe selectively accumulated in tumor tissue within as early as 0.5 h postinjection. The results of the surgical resection experiment revealed that the tumor could be entirely removed under the guidance of NIR imaging, thereby indicating the probe's efficacy in surgical navigation. CYP1B1 expression was found to be upregulated in adriamycin (ADR)-resistant breast cancer cells, MCF-7/ADR. Consequently, the sensitivity of CYP1B1 overexpressed cells, MCF-7/1B1, to ADR was significantly reduced, with an IC₅₀ value of 0.586 ± 0.0934 μM, compared to the parental MCF-7 cells with an IC₅₀ value of 0.183 ± 0.0444 μM. In vivo and ex vivo imaging assays conducted on MCF-7/ADR tumor-bearing mice demonstrated that the probe was specifically enriched in tumor sites, suggesting its potential for monitoring chemotherapy resistance in breast cancer. This study expands the scope of application for NIR probe 1, establishing its utility in breast cancer diagnosis through fluorescence-photoacoustic dual-model imaging, monitoring of chemotherapy resistance, and guidance for surgical resection. This strategy paves the way for novel approaches to precise and personalized treatment for breast cancer patients.