Targeting temporal dynamics of microenvironmental factors halts tumor migration and alleviates effects of dynamic tumor heterogeneity

Abstract

SummaryTargeting microenvironmental factors that foster migratory cell phenotypes is a promising strategy for halting tumor migration. However, lack of mechanistic understanding of the process impedes pharmaceutical drug development. Using a novel 3D microtumor model with tight control over tumor size, we recapitulated tumor size-induced hypoxic microenvironment and emergence of migratory phenotypes in epithelial T47D breast microtumors as well as those of patient-derived primary metastatic breast cancer cells, mesothelioma cells and lung cancer xenograft cells (PDX). The microtumor models from various patient-derived tumor cells and PDX cells revealed upregulation of tumor secretome, matrix metalloproteinase-9 (MMP9), fibronectin (FN), and soluble E-cadherin (sE-CAD) consistent with the clinically reported elevated levels of FN and MMP9 in the patient breast tumors compared to healthy mammary gland. We further showed that the tumor secretome induces migratory phenotype in nonhypoxic, non-migratory small microtumors. Subsequent mathematical model analysis identified a two-stage microtumor progression and migration mechanism, i.e., hypoxia induces migratory phenotype in the early initialization stage, which then becomes self-sustained through positive feedback loop established among the secretome. Both computational and experimental studies showed that inhibition of tumor secretome effectively halts microtumor migration despite tumor heterogeneity, while inhibition of the hypoxia is effective only within a time window and is compromised by tumor-to-tumor variation of the growth dynamics, supporting our notion that hypoxia initiates migratory phenotypes but does not sustain it. In summary, we show that targeting temporal dynamics of evolving microenvironments during tumor progression can halt and bypass major hurdle of tumor heterogeneity.peer-reviewed)

P4HA2: A link between tumor-intrinsic hypoxia, partial EMT and collective migration

“…Our earlier work has demonstrated that the large 600µm microtumors with tumor-intrinsic hypoxia exhibit partial EMT phenotype characterized by gain of mesenchymal marker (VIM) without loss of epithelial marker (E-CAD) [21]. Based on these initial findings, we further investigated partial EMT signatures enriched by tumor-intrinsic hypoxia in large 600µm microtumors on day 1 and day 6.…”

“…T47D cell line was purchased from American type culture collection (ATCC). Characterization and authentication of T47D cells was done at the University of Arizona Genomic Core facility using PowerPlex16HS PCR kit as previously described [20,21]. All cell culture supplies and media were procured from Corning ® and Mediatech ® , respectively, unless otherwise specified.…”

“…To study how tumor-intrinsic hypoxia drives partial EMT phenotype, large 600µm microtumors were cultured over 6-day period. The small non-hypoxic and non-migratory 150µm microtumors [20,21] served as controls.…”

“…To evaluate the effect of P4HA inhibition (P4HA2i) on collective migration of microtumors, number of migrating and non-migrating microtumors were counted on day 3 and day 6 (control versus treated microtumor devices). In addition, the control versus treated microtumors were also imaged at 4x and 10x magnification (Zeiss Primo-vert) on day 3 and day 6, and distance of migration (d) was calculated as described previously [21] for evaluating migration kinetics. Post-treatment, microtumors were collected at day 3 and day 6, respectively from control (untreated) and P4HA2i-treated devices for mRNA isolation.…”

“…Post-treatment, microtumors were collected at day 3 and day 6, respectively from control (untreated) and P4HA2i-treated devices for mRNA isolation. [21,25].…”