High-Speed Live-Cell Interferometry: A New Method for Quantifying Tumor Drug Resistance and Heterogeneity

Abstract

We report the development of high-speed live-cell interferometry (HSLCI), a new multisample, multidrug testing platform for directly measuring tumor therapy response via real-time optical cell biomass measurements. As a proof of concept, we show that HSLCI rapidly profiles changes in biomass in BRAF inhibitor (BRAFi)-sensitive parental melanoma cell lines and in their isogenic BRAFi-resistant sublines. We show reproducible results from two different HSLCI platforms at two institutions that generate biomass kinetic signatures capable of discriminating between BRAFi-sensitive and -resistant melanoma cells within 24 h. Like other quantitative phase imaging (QPI) modalities, HSLCI is well-suited to noninvasive measurements of single cells and cell clusters, requiring no fluorescence or dye labeling. HSLCI is substantially faster and more sensitive than field-standard growth inhibition assays, and in terms of the number of cells measured simultaneously, the number of drugs tested in parallel, and temporal measurement range, it exceeds the state of the art by more than 10-fold. The accuracy and speed of HSLCI in profiling tumor cell heterogeneity and therapy resistance are promising features of potential tools to guide patient therapeutic selections.

QPI Allows in vitro Drug Screening of Triple Negative Breast Cancer PDX Tumors and Fine Needle Biopsies

“…Earlier work by our group has established that live cell mass accumulation rates measured by QPI can be used to assess response to cytostatic or cytotoxic cancer drugs. These mass accumulation-based responses were found to be concordant with traditional cell counting and fluorescent reporter viability assays in a variety of cancer types, including breast, multiple myeloma, and melanoma [9][10][11].…”

“…Though statistically significant, the small magnitude of response and the lack of a clear relationship to escalating doses suggests that pablociclib would not be an effective treatment in vivo for this tumor. Past experience with HSLCI dose response curves informs us that a fluctuation of this magnitude (∼0.1%) is relatively insignificant and within typical random error (such as tumor sampling heterogeneity or pipetting error) for such samples [9,10]. This conclusion is supported by the results of a luciferase assay, which showed a similar marginal response at the highest tested dose of 10 µM.…”

“…The total number of cells in each sample well can vary widely depending on the individual tumor. To compensate for these issues, which result in low or variable viable cell counts, we sought to increase the overall throughput vs. that reported previously [10].…”

Quantitative Phase Imaging for Label-Free Analysis of Cancer Cells—Focus on Digital Holographic Microscopy

“…Interestingly, results presented on the individual cellular level of prostate cancer cells and mouse fibroblast cells treated with cell death-inducing drugs showed that these cell types behaved very differently [82]. Using rapid profiling with high-speed live-cell interferometry, Huang and co-workers recently showed that the proto-oncogene B-Raf (BRAF)-inhibitor sensitive melanoma cell lines differed in measurements of optical cell biomass [62]. Interestingly, within 24 h, biomass kinetic signatures were obtained for three Interestingly, several DH parameters that were measured, including cell number, area, thickness, and volume, were decreased after Etoposide treatment of the Jurkat cells (Table 2).…”

Machine Learning with Optical Phase Signatures for Phenotypic Profiling of Cell Lines

“…The nucleus , actin cytoskeleton , membrane‐bound organelles , and cytoplasm contribute to the cell phase profile. Events that significantly affect a cell's morphology or subcellular phase texture are often detected longitudinally or by comparing distinct cell populations . For example, time‐lapse imaging of single cells reveals the effects on phase signals of agents inducing apoptosis , cytoskeletal disruption , or reduced proliferation .…”