Shedding Light on Cancer: Noninvasive fluorescence-based approaches for detecting and assessing functional events associated with pre-cancers.
Abstract: The most
prevalent human diseases, such as cancer, diabetes, and obesity, involve abnormal
metabolic states that lead to severe tissue dysfunction. Noninvasive methods that
provide spatially resolved metabolic information could substantially advance our
understanding of these diseases, leading to better detection and treatment methods.
Here, we report on the capabilities of nonlinea... read morer microscopy as a high-resolution,
label-free optical tool for characterization of cells and tissues. Specifically, we
assess healthy and precancerous human papillomavirus (HPV) models with the goal of
associating functional tissue changes with optical biomarkers. Through the endogenous
fluorescence of keratins, lipids, and nicotinamide and flavin adenine dinucleotides
(NADH and FAD, respectively), we quantify modifications in tissue structure as well as
the optical redox ratio of FAD/(NADH+FAD), which reflects cell metabolic state. To date,
direct comparison between detected optical redox and actual biochemical changes have
been elusive. We show NADH and FAD fluorescence signals are strongly correlated to NADH
and FAD concentrations as measured by liquid chromatography-tandem mass spectrometry
(LC-MS/MS). Furthermore, since NADH fluorescence emanates primarily from mitochondria,
we present a novel Fourier-based image processing method to probe fine changes in
mitochondrial features. Due to the interdependence of mitochondrial structure and
function, these mitochondrial metrics provide a complimentary measure of cell function.
We demonstrate that together, these optical parameters are sensitive to structural and
functional changes induced by differentiation, disease, and aberrant cell signaling.
Such methods could significantly contribute to the elucidation of cellular and
extracellular events that incite and support cancer progression, leading to better
methods for detection and treatment.
Thesis (Ph.D.)--Tufts University, 2013.
Submitted to the Dept. of Biomedical Engineering.
Advisor: Irene Georgakoudi.
Committee: David Kaplan, Jonathan Garlick, Nikiforos Kollias, and Karl Munger.
Keywords: Biomedical engineering, Biophysics, and Oncology.read less