Biology subjects

Corr, D. T.

Publications and source records attributed to Corr, D. T..

5 recordsLinked to original sources

bioRxiv2026

A DMT1-dependent iron-endoplasmic reticulum-extracellular matrix axis regulates cancer cell invasion

Intracellular iron homeostasis is increasingly recognized as a regulator of cancer cell behavior, but how iron distribution influences extracellular matrix (ECM) organization and invasion remains poorly understood. Here, we show that loss of divalent metal transporter 1 (DMT1/SLC11A2) disrupts intracellular iron homeostasis and promotes cancer cell invasion through an iron-ER-ECM axis. In MDA-MB-231 cells, DMT1 knockout (KO) reduced total iron content but increased the labile iron pool (LIP) in both 2D and 3D culture models, indicating altered intracellular iron distribution. Across transcriptomic and phenotypic readouts, DMT1-dependent effects were more evident in 3D than in 2D models, with DMT1 KO inducing endoplasmic reticulum (ER) stress and impaired collagen/ECM organization. Functionally, the DMT1-loss phenotype was marked by reduced 2D motility, whereas in 3D spheroid models DMT1 KO cells displayed enhanced invasive outgrowth in both Matrigel and collagen matrices. Iron chelation further modulated this phenotype in a DMT1-dependent manner. Pharmacologic induction of ER stress phenocopied the loose spheroid architecture and invasive behavior, supporting ER stress as a mechanistic link between altered iron handling and ECM destabilization. Together, these findings identify intracellular iron distribution, rather than total iron abundance alone, as a determinant of ECM integrity and context-dependent cancer cell invasion. One Sentence Summary: Iron misrouting, not iron excess, drives ER stress and collagen failure that unleash invasion in triple-negative breast cancer.

cancer biology↗

bioRxiv2022

Sophorolipid Candidates Demonstrate Cytotoxic Efficacy Against 2D and 3D Breast Cancer Models

Sophorolipids are biosurfactants derived from the non-pathogenic yeast Starmerella bombicola, with potential efficacy in anti-cancer applications. Simple and cost-effective synthesis of these drugs makes them a promising alternative to traditional chemotherapeutics, pending their success in preliminary drugscreening. Drug screening typically utilizes 2D cell monolayers due to their simplicity and potential for high-throughput assessment. However, 2D assays fail to capture the complexity and 3D context of the tumor microenvironment, and have consequently been implicated in the high percentage of drugs investigated in vitro that later fail in clinical trials. We screened two sophorolipid candidates and clinically-used chemotherapeutic, doxorubicin, on in vitro breast cancer models ranging from 2D monolayers to 3D spheroids, employing Optical Coherence Tomography to confirm these morphologies. We calculated corresponding IC50 values for these drugs and found one of the sophorolipids to have comparable toxicities to the chemotherapeutic control. Our findings show increased drug resistance associated with model dimensionality, such that all drugs tested showed that 3D spheroids exhibited higher IC50 values than their 2D counterparts. These findings demonstrate promising preliminary data to support the use of sophorolipids as a more affordable alternative to traditional clinical interventions and demonstrate the importance of 3D tumor models in assessing drug response.

pharmacology and toxicology↗

bioRxiv2022

Tendon-like cellular and matrix maturation in scaffold-free three-dimensional tendon cell culture using mouse tendon cells

Tendons transmit mechanical forces between muscle and bone. Their biomechanical function requires high tensile strength provided by highly organized collagen fibers. Tenocytes mainly drive tendon growth via extracellular matrix (ECM) production and organization. The biological mechanisms regulating tenocyte differentiation and morphological maturation have not been well-established, partly due to the lack of reliable in vitro systems that produce highly aligned collagenous tissues. In this study, we developed a scaffold-free, three-dimensional (3D) tendon culture system using mouse tendon cells and a differentially adherent growth channel. TGF{beta} treatment promoted tendon-like structure in the peripheral layer of the constructs with decreased cell density, decreased cell proliferation, increased thickness, and more elongated cells within highly aligned extracellular matrix. The constructs were used to understand the function of TGF{beta} signaling in tenogenic differentiation, collagen fibrillogenesis, and biomechanical properties. This scaffold-free 3D constructs system can serve as a reliable in vitro system to study underlying biological mechanisms that regulate cellular and matrix maturation in tendon development and growth.

bioengineering↗

bioRxiv2022

DMT1 bridges endosomes and mitochondria to modulate mitochondrial iron translocation

Transient "kiss-and-run" endosome-mitochondria interactions can mediate mitochondrial iron translocation (MIT) but the associated mechanisms are still elusive. We show that Divalent Metal Transporter 1 (DMT1) modulates MIT via endosome-mitochondria interactions in invasive MDA-MB-231, but not in non-invasive T47D breast cancer cells. CRISPR/Cas9-based DMT1 knockout (KO) stable cells were used to demonstrate that DMT1 regulates MIT, endosomal speed, and labile iron pool (LIP) levels only in MDA-MB-231. DMT1 silencing increases PINK1/Parkin mitophagy markers, the autophagy marker LC3B, as well as mitochondrial ferritin in MDA-MB-231, but not in T47D. Strikingly, re-expression of DMT1 in MDA-MB-231 DMT KO cells rescues all protein levels evaluated. DMT1 silencing decreases Tom20 colocalization with PMPCB, a DMT1 interactor that regulates mitophagy hyperactivation. In MDA-MB-231 both mitochondrial metabolism and invasion were impaired by DMT1 silencing and rescued by DMT1 re-expression. DMT1 acts as a bridge between endosomes and mitochondria to support higher MIT/lower LIP levels, which are necessary for sustaining mitochondrial bioenergetics and invasive cancer cell migration. SummaryCellular iron metabolism is tightly regulated, and cancer cells rely on mitochondrial iron for malignancy. Here, we report that the divalent metal transporter DMT1 serves as a bridge between endosomes and mitochondria regulating mitochondrial iron translocation in breast cancer cells.

cell biology↗

bioRxiv2021

A bioreactor for controlled electromechanical stimulation of developing scaffold-free constructs

Bioreactors are commonly used to apply biophysically-relevant stimulations to tissue-engineered constructs in order to explore how these stimuli influence tissue development, healing, and homeostasis. These bioreactors offer great flexibility as key features of the stimuli (e.g., duty cycle, frequency, amplitude, duration) can be controlled to elicit a desired cellular response. Controlled delivery of mechanical and/or electrical stimulation has been shown to improve the structure and function of engineered tissue constructs, compared to unstimulated controls, for applications in various musculoskeletal soft tissues. However, most bioreactors that apply mechanical and electrical stimulations, do so to a scaffold after the construct has developed, preventing study of the influence these stimuli have on early construct development. Thus, there is a need for a bioreactor that allows the direct application of mechanical and electrical stimulation to constructs as they develop, to enable such exploration and to better mimic key aspects of tissue development. Hence, the objective of this study was to develop and calibrate a bioreactor to deliver precise mechanical and electrical stimulation, either independently or in combination, to developing scaffold-free tissue constructs. Standard Flexcell Tissue Train plates were modified with stainless steel loading pins and stimulating electrodes to integrate direct mechanical and electrical stimulation, respectively, into our established scaffold-free, single-fiber engineering platform. Linear calibration curves were established, then used to apply precise dynamic mechanical and electrical stimulations, over a range of physiologically relevant strains (0.50, 0.70, 0.75, 1.0, 1.5%) and voltages (1.5, 3.5 V), respectively. Once calibrated, applied mechanical and electrical stimulations were not statistically different from their desired target values, and were consistent whether delivered independently or in combination. Indeed, concurrent delivery of mechanical and electrical stimulation resulted in a negligible change in mechanical (< 2%) and electrical (<1%) values, from their independently-delivered values. With this calibrated bioreactor, we can apply precise, controlled, reproducible mechanical and electrical stimulations, alone or in combination, to scaffold-free, tissue engineered constructs as they develop, to explore how these stimuli can be leveraged to advance and accelerate functional tissue engineering in a variety of musculoskeletal soft tissues. IMPACT STATEMENTAs the importance of biophysical stimulation in tissue engineering continues to be recognized and incorporated, this bioreactor provides a platform to further our understanding of the roles independent or combined mechanical and electrical stimulation have in tissue development and functional maturation, and may inform future tissue engineering approaches for clinical applications.

bioengineering↗