Quantitative imaging reveals heterogeneous growth dynamics and treatment-dependent residual tumor distributions in a three-dimensional ovarian cancer model.
Three-dimensional tumor models have emerged as valuable in vitro research tools, though the power of such systems as quantitative reporters of tumor growth and treatment response has not been adequately explored. We introduce an approach combining a 3-D model of disseminated ovarian cancer with high-throughput processing of image data for quantification of growth characteristics and cytotoxic response. We developed custom MATLAB routines to analyze longitudinally acquired dark-field microscopy images containing thousands of 3-D nodules. These data reveal a reproducible bimodal log-normal size distribution. Growth behavior is driven by migration and assembly, causing an exponential decay in spatial density concomitant with increasing mean size. At day 10, cultures are treated with either carboplatin or photodynamic therapy (PDT). We quantify size-dependent cytotoxic response for each treatment on a nodule by nodule basis using automated segmentation combined with ratiometric batch-processing of calcein and ethidium bromide fluorescence intensity data (indicating live and dead cells, respectively). Both treatments reduce viability, though carboplatin leaves micronodules largely structurally intact with a size distribution similar to untreated cultures. In contrast, PDT treatment disrupts micronodular structure, causing punctate regions of toxicity, shifting the distribution toward smaller sizes, and potentially increasing vulnerability to subsequent chemotherapeutic treatment.
Harvard Medical School, Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts 02114, USA.
Jonathan P
JP
Celli
Imran
I
Rizvi
Conor L
CL
Evans
Adnan O
AO
Abu-Yousif
Tayyaba
T
Hasan
D000970:Antineoplastic Agents / Q000627:therapeutic use; D016190:Carboplatin / Q000627:therapeutic use; D045744:Cell Line, Tumor; D003094:Collagen; D004338:Drug Combinations; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007797:Laminin; D018613:Microscopy, Confocal / Q000379:methods; D008954:Models, Biological; D018365:Neoplasm, Residual; D055620:Optical Phenomena; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000473:pathology*; D010778:Photochemotherapy; D011509:Proteoglycans; D018874:Spheroids, Cellular / Q000187:drug effects / Q000473:pathology; D059008:Time-Lapse Imaging
D000970:Antineoplastic Agents; D004338:Drug Combinations; D007797:Laminin; D011509:Proteoglycans; C059485:matrigel; D003094:Collagen; D016190:Carboplatin