Kaleb Ott
Pronouns: He/Him/His
Research Mentor(s): Carole Parent
Research Mentor School/College/Department: Pharmacology / Medicine
Program: UROP
Session: Session 4 (1:40pm – 2:30pm)
Authors: Kaleb Ott, Shuvasree SenGupta
Abstract
Tumor-associated neutrophils (TANs) have been identified as prominent members of the tumor microenvironment and are implicated in promoting tumor progression in breast cancer. Previous work has revealed a robust neutrophil recruiting ability of the more aggressive triple-negative breast cancer subtype (TNBC) compared to poorly aggressive variants. Understanding the molecular mechanisms that regulate neutrophil migration toward aggressive breast tumors is poised to aid in the development of effective targeted therapies to manipulate neutrophil recruitment to tumors. Epithelial-to-mesenchymal transition (EMT) is a well-established process during cancer progression that promotes cancer aggressiveness by inducing cells to undergo morphological and phenotypic changes and acquire migratory and invasive properties. Preliminary studies from the lab noted increased neutrophil recruitment by human premalignant breast epithelial M2 cells after stimulation with a combination of EMT-inducing factors, TNF-? and TGF-ß. We hypothesize that increased neutrophil recruitment by cancer cells following EMT-inducing chemical treatment depends on regulatory EMT transcription factors. To test this hypothesis, we compared EMT-associated changes in cell morphology, marker expression, and neutrophil recruitment ability of M2 cells that were genetically modified to overexpress or knocked out of Twist, a key EMT transcription factor. EMT-inducing treatment led to elongated mesenchymal morphology in control M2, M2 Twist, and M2 Twist KO cells when assessed with bright-field microscopy. Western blot analysis and immunofluorescence imaging also revealed increased expression of the mesenchymal markers fibronectin and N-cadherin with treatment regardless of the presence of Twist. Finally, in a transwell migration assay, conditioned media (CM) from all three treated cell types induced a greater percentage of neutrophil migration compared to the CM harvested from untreated counterparts. Together, these results suggest that enhanced neutrophil recruitment by M2 cells in response to EMT-inducing treatment is independent of Twist and calls for future investigation into other key EMT transcription factors.
