Biology subjects

Oudin, M. J.

Publications and source records attributed to Oudin, M. J..

11 recordsLinked to original sources

bioRxiv2026

Targeting fibroblast activation suppresses chemotherapy-induced pro-invasive remodeling of the extracellular matrix

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that accounts for nearly 20% of breast cancer diagnoses. Despite recent approvals of novel therapeutic agents for TNBC, neoadjuvant chemotherapy remains part of standard of care treatment for TNBC patients. However, approximately 60% of TNBC patients who received neoadjuvant chemotherapy fail to achieve pathological complete response and face significantly elevated risks of recurrence and distant metastasis. We have shown that chemotherapy can induce significant changes in TNBC tumor extracellular matrix (ECM) that drive tumor cell invasion and may contribute to recurrence. Here, we investigate how chemotherapy drugs can impact resident fibroblasts, the major generators of ECM in the breast tissue. We find that chemotherapy activates fibroblasts and that doxorubicin specifically induces the production of pro-invasive ECM by fibroblasts via TGF-{beta}/Smad3 signaling. An FDA-approved tyrosine kinase inhibitor nintedanib suppressed doxorubicin-induced fibroblast activation and pro-invasive ECM production by fibroblasts in vitro. Additionally, in a TNBC mouse model, nintedanib reduced fibroblast activation markers in tumors, suppressed tumor cell motility in the tumor ECM, and reduced lung metastasis. These findings demonstrate a novel mechanism by which chemotherapy can induce fibroblast activation and imply that targeting fibroblast activation reduces chemotherapy-induced metastasis in TNBC.

cancer biology↗

bioRxiv2025

Cell-line specific role of Cathepsin B in triple-negative breast cancer growth, invasion and response to chemotherapy

Cathepsins are papain-family cysteine proteases known to play a cell-intrinsic role in protein degradation in the lysosome, as well as in digesting ECM and surface proteins after being secreted. Both of these functions are known to mediate pro-tumorigenic effects of CTSB in a range of cancers. Here, we specifically investigate the role of CTSB in TNBC, an aggressive subtype of breast cancer, where we find that high expression of CTSB in TNBC is associated with better outcomes. We used CRISPR to knockout CTSB in two highly metastatic TNBC cell lines, MDA-MB-231 and MDA-MB-468, and find different effects. In MDA-MB-231 cells, knockout of CTSB has no effect on cell viability, increases tumor cell 3D invasion in an ECM-independent manner, and increases sensitivity to many standard of care chemotherapy drugs. However, in MDA-MB-468 cells, knockout of CTSB increases cell viability, decreases tumor cell 3D invasion, in an ECM-independent manner, and drives resistance to certain chemotherapy drugs without affecting response to others. We find that in these cells, CTSB is not secreted, and that differential downstream mTOR and Akt activation can explain the differences seen in these phenotypes. Overall, our studies demonstrate that CTSB can regulate TNBC cell phenotypes via its lysosomal cell-intrinsic role, but that effects are cell-line specific, suggesting potential heterogeneity in the role of CTSB in TNBC.

cancer biology↗

bioRxiv2025

A splice-switching antisense oligonucleotide approach for pediatric genetic epilepsies

Summary ParagraphVariants in ion channel genes are common causes of pediatric epilepsy, often leading to intractable seizures, developmental delay and other comorbidities, which increases risk of death. Pathogenic variants in the SCN8A gene, which encodes a voltage-gated sodium channel critical for action potential generation in the brain, account for [~]1% of genetic epilepsies. The voltage sensor in SCN8A domain 1 is encoded by one of two developmentally-regulated mutually exclusive alternative exons, 5N and 5A. We observe that variants in these exons are more likely to cause infantile spasms, a severe seizure type, than variants elsewhere in SCN8A, and that some pathogenic variants affect exon 5 splicing, impacting patient phenotype. Molecular and evolutionary analyses implicate the exon sequences of these and other voltage-gated ion channel alternative exons in splicing regulation. We identified antisense oligonucleotides (ASOs) that shift splicing of SCN8A exon 5N to 5A or vice versa. These ASOs normalize neuronal activity in patient-derived iPSC neurons, and reduce seizures and motor impairment and extend lifespan in a new exon 5N mutant mouse model. Our results demonstrate that splice-switching ASOs can effectively reduce the expression of pathogenic isoforms and rescue both seizure and non-seizure phenotypes. Similar approaches should be applicable to pediatric genetic epilepsies caused by mutations in other ion channel alternative exons.

neuroscience↗

bioRxiv2025

Triple-Negative Breast Cancer Cells Activate Sensory Neurons via TRPV1 to Drive Nerve Outgrowth and Tumor Progression

The tumor microenvironment in triple-negative breast cancer (TNBC) is characterized by increased sensory nerve density, which contributes to cancer progression by promoting migration and metastasis. However, the origin of tumor-innervating nerves and the mechanisms driving sensory innervation into tumors remain poorly understood. Using in vivo retrograde labeling techniques, we show that mammary tumors are associated with an increase in nerves originating from the dorsal root ganglia. Additionally, we find that TNBC cells trigger stress and activation markers and induce neuronal firing in a transient receptor potential anilloid subtype 1 (TRPV1)-dependent manner. In both 2D and 3D cell culture models, TNBC cells promote outgrowth of sensory nerves that is abrogated with Trpv1 knockout. We identified c-Jun and IL-6 as an effector of neurite outgrowth that acts downstream of TRPV1 to promote outgrowth in vitro. Finally, in Trpv1 knockout mice, TNBC tumors exhibit delayed growth and reduced lung metastasis. These findings suggest that a critical role for TRPV1 in tumor-nerve crosstalk, offering a potential target to reduce metastatic disease.

cancer biology↗

bioRxiv2023

Age and obesity-driven changes in the extracellular matrix of the primary tumor and metastatic site influence tumor invasion and metastatic outgrowth

Younger age and obesity increase the incidence and metastasis of triple-negative breast cancer (TNBC), an aggressive subtype of breast cancer. The extracellular matrix (ECM) promotes tumor invasion and metastasis. We characterized the effect of age and obesity on the ECM of mammary fat pads, lungs, and liver using a diet-induced obesity (DIO) model. At 4 week intervals, we either injected the mammary fat pads with allograft tumor cells to characterize tumor growth and metastasis or isolated the mammary fat pads and livers to characterize the ECM. Age had no effect on tumor growth but increased lung and liver metastasis after 16 weeks. Obesity increased tumor growth starting at 12 weeks, increased liver metastasis only at 4 weeks, and weight gain correlated to increased lung but not liver metastasis. Utilizing whole decellularized ECM coupled with proteomics, we found that early stages of obesity were sufficient to induce changes in the ECM composition and invasive potential of mammary fat pads with increased abundance of pro-invasive ECM proteins Collagen IV and Collagen VI. We identified cells of stromal vascular fraction and adipose stem and progenitor cells as primarily responsible for secreting Collagen IV and VI, not adipocytes. We characterized the changes in ECM in the lungs and liver, and determined that older age decreases the metastatic potential of lung and liver ECM while later-stage obesity increases the metastatic potential. These data implicate ECM changes in the primary tumor and metastatic microenvironment as mechanisms by which age and obesity contribute to breast cancer progression. SignificanceYounger age and obesity increase the incidence and metastasis of triple-negative breast cancer. Our data suggest that changes in the breast, lung and liver ECM are driving some of these effects.

cancer biology↗

bioRxiv2023

Cell morphology best predicts tumorigenicity and metastasis in vivo across multiple TNBC cell lines of different metastatic potential

BackgroundMetastasis is the leading cause of death in breast cancer patients. For metastasis to occur, tumor cells must invade locally, intravasate, and colonize distant tissues and organs, all steps that require tumor cell migration. The majority of studies on invasion and metastasis rely on human breast cancer cell lines. While it is known that these cells have different properties and abilities for growth and metastasis, the in vitro morphological, proliferative, migratory, and invasive behavior of these cell lines and their correlation to in vivo behavior is poorly understood. Thus, we sought to classify each cell line as poorly or highly metastatic by characterizing tumor growth and metastasis in a murine model of six commonly used human triple-negative breast cancer xenografts, as well as determine which in vitro assays commonly used to study cell motility best predict in vivo metastasis. MethodsWe evaluated the liver and lung metastasis of human TNBC cell lines MDA-MB-231, MDA-MB-468, BT549, Hs578T, BT20, and SUM159 in immunocompromised mice. We characterized each cell lines cell morphology, proliferation, and motility in 2D and 3D to determine the variation in these parameters between cell lines. ResultsWe identified MDA-MB-231, MDA-MB-468, and BT549 cells as highly tumorigenic and metastatic, Hs578T as poorly tumorigenic and metastatic, BT20 as intermediate tumorigenic with poor metastasis to the lungs but highly metastatic to the livers, and SUM159 as intermediate tumorigenic but poorly metastatic to the lungs and livers. We showed that metrics that characterize cell morphology are the most predictive of tumor growth and metastatic potential to the lungs and liver. Further, we found that no single in vitro motility assay in 2D or 3D significantly correlated with metastasis in vivo. ConclusionsOur results provide an important resource for the TNBC research community, identifying the metastatic potential of 6 commonly used cell lines. Our findings also support the use of cell morphological analysis to investigate the metastatic potential and emphasize the need for multiple in vitro motility metrics using multiple cell lines to represent the heterogeneity of metastasis in vivo.

cancer biology↗

bioRxiv2021

Potassium channel-driven bioelectric signaling regulates metastasis in triple-negative breast cancer

There is a critical need to better understand the mechanisms that drive local cell invasion and metastasis to develop new therapeutics targeting metastatic disease. Bioelectricity is an important mediator of cellular processes and changes in the resting membrane potential (RMP) are associated with increased cancer cell invasion. However, the mechanism is not well understood. Our data demonstrate that altering the RMP of triple-negative breast cancer (TNBC) cells by manipulating potassium channel expression increases in vitro invasion, in vivo tumor growth, and metastasis, and is accompanied by changes in gene expression associated with cell adhesion. We describe a novel mechanism for RMP-mediated cell migration involving cadherin-11 and the MAPK pathway. Importantly, we identify a new strategy to target metastatic TNBC in vivo by repurposing FDA-approved potassium channel blockers. Our results provide an understanding of the mechanisms by which bioelectricity regulates cancer cell invasion and metastasis that could lead to a new class of therapeutics for patients with metastatic disease.

cancer biology↗

bioRxiv2021

Chemotherapy-induced collagen IV drives cancer cell invasion through activation of Src/FAK signaling

Triple-negative breast cancer (TNBC) is the most aggressive and deadly subtype of breast cancer, accounting for 30,000 cases annually in the US. While there are several clinical trials ongoing to identify new agents to treat TNBC, the majority of TNBC patients are treated with anthracycline- or taxane-based chemotherapies in the neoadjuvant setting, followed by surgical resection and adjuvant chemotherapy. While many patients respond well to this approach, as many as 25% will suffer local or metastatic recurrence within five years. Understanding the mechanisms that drive recurrence after chemotherapy treatment is critical to improving survival for patients with TNBC. It is well-established that the extracellular matrix, which provides structure and support to tissues, is a major driver of tumor growth, local invasion and dissemination of cancer cells to distant metastatic sites. In the present study, we show that decellularized extracellular matrix (dECM) obtained from chemotherapy-treated mice increases invasion of treatment-naive breast cancer cells compared to vehicle-treated dECM. Using tandem-mass-tag proteomics, we further demonstrate that anthracycline- and taxane-based chemotherapies induce drug-specific changes in tumor ECM composition. We identify the basement membrane protein collagen IV as significantly upregulated in the ECM of chemotherapy-treated mice and patients treated with neoadjuvant chemotherapy. We show that collagen IV drives invasion via Src/FAK signaling and that inhibiting collagen IV-driven signaling decreases invasion in chemotherapy-treated dECM. These studies provide a novel mechanism by which chemotherapy may induce metastasis via effects on ECM composition. One Sentence SummaryChemotherapy alters the extracellular matrix of breast tumors leading to increased invasion of residual cancer cells.

cancer biology↗

bioRxiv2021

RNA-sequencing indicates immune cell signaling and inflammatory gene expression in cardiac fibroblasts increases with developmental age

BackgroundCardiac fibroblasts are responsible for extracellular matrix turnover and repair in the cardiac environment and serve to help facilitate immune responses. However, it is well established that they have significant phenotypic heterogeneity with respect to location, physiological conditions, and developmental age. The goal of this study was to provide an in-depth transcriptomic profile of cardiac fibroblasts derived from rat hearts at fetal, neonatal, and adult developmental ages to ascertain variations in gene expression that may drive functional differences in these cells at these specific stages of development. ResultsWe performed RNA-seq of cardiac fibroblasts isolated from fetal, neonatal, and adult rats was performed and compared to the rat genome. Principal component analysis of RNA-seq data suggested data variance was predominantly due to developmental age. Differential expression and Gene set enrichment analysis against Gene Ontology and Kyoto Encyclopedia of Genes and Genomes datasets indicated an array of differences across developmental ages, including significant decreases in cardiac development and cardiac function-associated genes with age, and a significant increase in immune and inflammatory-associated functions - particularly immune cell signaling, and cytokine and chemokine production - with respect to increasing developmental age. ConclusionThese results reinforce established evidence of diverse phenotypic heterogeneity of fibroblasts with respect to developmental age. Further, based on our analysis of gene expression, age-specific alterations in cardiac fibroblasts may play a crucial role in observed differences in cardiac inflammation and immune response observed across developmental ages.

cell biology↗

bioRxiv2020

Obesity-driven changes in ECM composition promote local invasion and metastasis of breast tumors

The extracellular matrix (ECM) is a major component of the tumor microenvironment that supports cellular growth, promotes local invasion from the primary tumor, and contributes to metastatic outgrowth in sites of colonization. Obesity is a systemic disease that causes chronic inflammation which can lead to ECM deposition and ultimately fibrosis in adipose tissues such as the mammary gland. Overweight breast cancer patients have increased metastasis to the lung and liver, exhibit resistance to chemotherapy and have worse outcomes. We found that ECM isolated from the mammary gland of both tumor-bearing and obese mice increased invasion of breast cancer cells and set out to investigate whether obesity-driven changes in ECM could identify novel drivers of invasion and metastasis in breast cancer. We performed proteomics of the mammary fat pads of both lean and obese mice and identified the entire landscape of obesity-driven ECM changes. In particular, we focused on Collagen VI, an ECM protein secreted by adipocytes in mammary tissues. Collagen VI is upregulated in the ECM of obese and tumor-bearing mice and is associated with poor outcome in human breast cancer. We found that Collagen VI drives adhesion, migration and invasion of several human breast cancer cell lines via crosstalk between the adhesion receptor NG2 and the receptor tyrosine kinase EGFR, and activation of MAPK signaling. Overall, these studies demonstrate that obesity can have profound effects on the ECM composition of tissues, which in turn can promote local invasion and metastasis.

cancer biology↗

bioRxiv2019

Defined extracellular ionic solutions to study and manipulate the cellular resting membrane potential

All cells possess an electric potential across their plasma membranes. While familiar in the context of excitable cells such as neurons, healthy non-excitable cells are also able to generate and receive bioelectric signals. The cellular resting membrane potential (RMP) regulates many factors in cell homeostasis, such as cell proliferation, differentiation and apoptosis. It is therefore critical to develop simple strategies to measure, manipulate and characterize this feature. Current studies to evaluate RMP rely on the patch clamp approach, which is technically challenging, low-throughput and not widely available to the scientific community. Here, we present a relatively simple methodology to functionally study the role of RMP in non-excitable cells by modulating it pharmacologically, and using a voltage-sensitive dye to characterize the contribution of individual ions to the RMP. Specifically, we define protocols for using extracellular solutions in which permeable ions (Na+, Cl- and K+) are substituted with non-permeable ions (N-Methyl-D-glucamine (NMDG), gluconate, choline, SO42-) to study and manipulate RMP in vitro. The resulting RMP modifications were assessed with both patch clamp and a voltage sensitive dye. Using an epithelial and cancer cell line, we demonstrate that the proposed ionic solutions can determine the relative contribution of ionic species in setting the RMP and be used to actively and selectively modify the RMP. The proposed method is simple and reproducible and will make the study of bioelectricity more readily available to the cell biology community by enabling functional modulation of RMP in most cellular assays.\n\nAuthor Disclosure StatementsNo competing financial interests exist.

cell biology↗