Striking a Lethal Blow to Chemoresistance
Tumor Chemosensitivity Laboratory (LQT), University of Costa Rica
Malignant tumors are heterogeneous, demonstrating a diverse population of cell morphologies and phenotypic profiles. This results in specific cancer types expressing dissimilar characteristics from one patient to the next, and chemotherapies targeted towards a specific tumor may not eradicate the entire cellular mass. Dr. Steve Quiros and his colleague, Dr. Rodrigo Mora, at the Tumor Chemosensitivity Laboratory (LQT), Faculty of Microbiology at the University of Costa Rica are taking a close look at mechanisms to circumvent these hurdles and increase the effectiveness of chemotherapies, cancer diagnostic tools and personalized treatments. Specifically, Dr. Quiros focuses on temporal changes within the DNA damage response when exposed to genotoxins. He notes, “When DNA is damaged, an intracellular network is activated that coordinates a variety of responses within the cell, like repair pathways, arrest of the cell cycle and some metabolic changes that determine cell death or survival; and ultimately, we want to modulate this response to make malignant cells die.”
His work is interested in the effect of genotoxic agents on the DNA damage response signaling network. This effect is measured at the individual cell level where changes in the abundance, localization and post-translational modification of proteins involved in this network are monitored over time. These experiments involve live cell image acquisition at a high frequency for long periods of time. “Using Laser Scanning Microscopy, I can only look at one condition, a couple of proteins at a time, and each run requires manual imaging, at frequent intervals, for days,” he explains. “It’s very limiting; almost impossible.”
To meet his needs for monitoring many experimental conditions with the appropriate time resolution, Dr. Quiros is now using the Cytation™ 3 Cell Imaging Multi-Mode Reader for his live-cell imaging experiments and time-lapse microscopy needs. “We are very satisfied,” Dr. Quiros comments. “The instrument is very easy for staff and students to learn, and the local sales representative is responsive and follows up in person to make sure that our needs are still being met.”
Dr. Steve Quiros
Now, the lab can analyze dozens of conditions with each run, and image full 96-well plates in no time. He adds, “In a single run, I now have data that previously took me months to gather; it’s incredible.” He particularly appreciates the laser autofocus cube, that provides the speed required to image a wide field per well in a full multiwell plate with no evident phototoxicity or photobleaching, even after several days of frequent measurements. This quantitative real time data is used to feed their models for a systems biology approach. Armed with powerful Cytation 3, Dr. Quiros is confident that his work will identify druggable targets within the DNA damage response to overcome chemoresistance.
Time-lapse videomicroscopy of cancer cells treated with a genotoxic agent. Blue: cell nuclei. Red: cell death. Cells were imaged for a total of 72 h.
To learn more about University of Costa Rica, visit their web site.
Thanks to Dr. Steve Quiros at University of Costa Rica for sharing his BioTek experience.