The molecular subtypes of breast cancer correlate more strongly to prognosis, treatment response, and local recurrence than the traditional classifications based on histopathology. The ability to determine the subtype of breast tumors during surgery or biopsy in real time would provide physicians with new diagnostic capabilities to screen suspicious lesions, to perform high-precision surgery on malignant and premalignant lesions, and to personalize treatment for patients. This work studied the potential of using the molecular subtypes as natural biomarkers for characterizing breast cancer with high-frequency ultrasound (10–100 MHz). We hypothesized that high-frequency ultrasound would be able to detect variations in cell biomechanical properties due to mutations found in aggressive subtypes (e.g., basal-like and Her2 +). These mutations alter the expression levels of proteins that regulate the actin cytoskeleton, thereby modifying the biomechanical and thus ultrasonic properties of the cells. Pulse-echo measurements were acquired in vitro from breast cancer cell lines with different subtypes. The results showed that each cell line produced a unique ultrasonic spectral signature. One of the cell lines additionally exhibited changes over time, possibly due to dedifferentiation. Correlation of the results to other cell characterization methods will also be presented. [This work was supported by Utah Valley University.]
High-frequency ultrasound (10–100 MHz) has been demonstrated to be sensitive to cell cytoskeletal changes. Cytoskeletal properties determine the biomechanical characteristics of cells and their role in many biomolecular processes. Examples include the aggressiveness and metastatic potential of breast cancer subtypes, T-cell activation during immune responses, and microtubule disintegration in Alzheimer’s disease. The objectives of this work were to optimize the use of high-frequency ultrasound to subtype breast cancer cells and to acoustically measure cytoskeletal modifications. Pulse-echo measurements of 7 breast cancer cell lines of different molecular subtypes were acquired over a 2.5-year period using a 50-MHz transducer immersed in the growth media of monolayer cell cultures. Cell reflections were isolated from the interfering cell-culture plate reflections, spectrally analyzed using Gaussian curve fits, and spectrally classified using a heat map. The heat map displayed distinct patterns that differentiated the cell lines by molecular subtype. Cell cultures were also treated with colchicine and sphingosylphosphorylcholine to observe modulation of the microtubule and actin components. Cell waveforms and spectra displayed time-dependent changes due to chemical modification of the cytoskeleton. These results further verify and improve the noninvasive use of high-frequency ultrasound to differentiate breast cancer subtypes and to monitor cytoskeletal alterations in real time.
Current methods for determining the molecular subtypes of breast cancer include DNA microarrays, immunohistochemical staining, and proteomic analysis. These methods are not easily transferable to real-time clinical applications such as the intraoperative assessment of margin or biopsy specimens. The development of a diagnostic method for rapidly determining the molecular subtype of malignant breast tissue in a clinical setting would represent a significant advance in breast cancer detection and treatment. Preliminary results suggest that high-frequency ultrasound may be sensitive to variations between breast cancer cell lines, and thus molecular subtype, due to a mechanism linking subtype mutations to the ultrasonic properties of the cells. This mechanism was explored using an integrated experimental and computational method. Ultrasonic scattering from breast cancer cells in vitro were simulated using a multipole-based approach. Variations between cell lines due to different molecular subtypes were modeled using a range of cell moduli and sizes. Model and experimental spectra were compared using principal component analysis (PCA). The results indicate the properties and thus molecular subtypes of breast cancer cells could potentially be determined by comparing their measured spectra to model spectra using a feature classification program such as PCA. [This work was supported by Utah Valley University.]
The biomechanical properties of cells can be greatly influenced by modifications of the cytoskeleton of the cell. Cytoskeletal modifications can often be linked to disease and disease pathways. Cancer metastasis has been previously associated with the cytoskeletal modifications that are induced by the addition of sphingosylphosphorylcholine (SPC) to panc-1 cells. SPC is a bioactive lipid that reorganizes keratin filaments in the cytoskeleton into a perinuclear shape that enables cell mobility. The maximum effect of SPC on the keratin reorganization has been previously observed as being concentration dependent, with 5-10μM concentration being optimal as observed through keratin immunostaining. In this work, high frequency ultrasound was used to observe the SPC induced keratin reorganization through an ultrasound signature. Ultrasound measurements were obtained using 10μM SPC and ~17μM SPC concentrations. Significant time-dependent changes in the ultrasound measurements were observed in the higher concentration of SPC as compared to control cell cultures that were not treated with SPC. In contrast, the lower concentration of SPC did not show visible changes in the ultrasound measurements taken. Future work will include optimizing a more specific concentration of SPC for observing changes in the ultrasound measurements taken of panc-1 cells.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.