An<i>in vitro</i>tumorigenesis model based on live cell-generated oxygen and nutrient gradients

Gilmore, Anne C.; Flaherty, Sarah J.; Somasundaram, Veena; Scheiblin, David A.; Lockett, Stephen; Wink, David A.; Heinz, William F.

doi:10.1101/2020.08.24.264580

Cited by 2 publications

(2 citation statements)

References 28 publications

(28 reference statements)

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“…Our earlier work has shown that murine 4T1 tumor cells can express high Nos2 and Cox2 levels and that Nos2/Cox2 blockade limited tumor growth (16, 17). Thus, 4T1 tumor bearing mice are representative of NOS2 Hi /COX2 Hi breast tumors.…”

Section: Resultsmentioning

confidence: 99%

NOS2 and COX2 Blockade Limits TNBC Disease Progression and Alters CD8⁺T Cell Spatial Orientation and Density

Somasundaram

Ridnour

Cheng

et al. 2022

Preprint

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Anti-tumor immune polarization is a key predictor of clinical outcomes to cancer therapy. An emerging concept influencing clinical outcome involves the spatial location of CD8+ T cells, within the tumor. Our earlier work demonstrated immunosuppressive effects of NOS2/COX2 tumor expression. Here, we show that NOS2/COX2 levels influence the polarization and spatial location of lymphoid cells including CD8+ T cells. Importantly, elevated tumor NOS2/COX2 correlated with exclusion of CD8+ T cells from the tumor epithelium. In contrast, tumors expressing low NOS2/COX2 had increased CD8+ T cell penetration into the tumor epithelium. Consistent with a causative relationship between these observations, pharmacological inhibition of COX2 with indomethacin dramatically reduced tumor growth of the 4T1 model of TNBC in both WT and Nos2-/- mice. This regimen led to complete tumor regression in ~20% of tumor-bearing Nos2-/- mice, and these animals were resistant to tumor rechallenge. Th1 cytokines were elevated in the blood of treated mice and intratumoral CD4+ and CD8+ T cells were higher in mice that received indomethacin when compared to control untreated mice. Multiplex immunofluorescence imaging confirmed our phenotyping results and demonstrated that targeted Nos2/Cox2 blockade improved CD8+ T cell penetration into the 4T1 tumor core. These findings are consistent with our observations in low NOS2/COX2 expressing breast tumors proving that COX2 activity is responsible for limiting the spatial distribution of effector T cells in TNBC. Together these results suggest that clinically available NSAID's may provide a cost-effective, novel immunotherapeutic approach for treatment of aggressive tumors including triple negative breast cancer.

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Section: Resultsmentioning

confidence: 99%

NOS2 and COX2 Blockade Limits TNBC Disease Progression and Alters CD8⁺T Cell Spatial Orientation and Density

Somasundaram

Ridnour

Cheng

et al. 2022

Preprint

Self Cite

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“…Microfluidic systems have been used to expose cells to different levels of ambient O 2 while simultaneously imaging the fluorescence intensity of ROS sensitive fluorescent probes 20 . Alternatively, cell culture chambers that restrict gas exchange with the environment have been used to create cell-generated oxygen gradients, and to image hypoxic gradients and other relevant parameters, such as mitochondrial membrane potential 21,22 .…”

Section: Openmentioning

confidence: 99%

Hypoxia, acidification and oxidative stress in cells cultured at large distances from an oxygen source

D’Aiuto

Hochmann

Millán

et al. 2022

Sci Rep

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Hypoxia is a condition frequently encountered by cells in tissues, whether as a normal feature of their microenvironment or subsequent to deregulated growth. Hypoxia can lead to acidification and increased oxidative stress, with profound consequences for cell physiology and tumorigenesis. Therefore, the interplay between hypoxia and oxidative stress is an important aspect for understanding the effects of hypoxic microenvironments on cells. We have used a previously developed variant of the method of coverslip-induced hypoxia to study the process of acidification in a hypoxic microenvironment and to simultaneously visualize intracellular levels of hypoxia and oxidative stress. We observed high accumulation of CO2 in hypoxic conditions, which we show is the main contributor to acidification in our model. Also, increased levels of oxidative stress were observed in moderately hypoxic cells close to the oxygen source, where the mitochondrial membrane potential was preserved. Conversely, cells at large distances from the oxygen source showed higher levels of hypoxia, milder oxidative stress and reduced mitochondrial membrane potential. Our results contribute to characterize the interplay between reduced oxygen levels, acidification and oxidative stress in a simple in vitro setting, which can be used to model cell responses to an altered environment, such as the early tumor microenvironment.

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Anin vitrotumorigenesis model based on live cell-generated oxygen and nutrient gradients

Cited by 2 publications

References 28 publications

NOS2 and COX2 Blockade Limits TNBC Disease Progression and Alters CD8⁺T Cell Spatial Orientation and Density

NOS2 and COX2 Blockade Limits TNBC Disease Progression and Alters CD8⁺T Cell Spatial Orientation and Density

Hypoxia, acidification and oxidative stress in cells cultured at large distances from an oxygen source

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Anin vitrotumorigenesis model based on live cell-generated oxygen and nutrient gradients

Cited by 2 publications

References 28 publications

NOS2 and COX2 Blockade Limits TNBC Disease Progression and Alters CD8+T Cell Spatial Orientation and Density

NOS2 and COX2 Blockade Limits TNBC Disease Progression and Alters CD8+T Cell Spatial Orientation and Density

Hypoxia, acidification and oxidative stress in cells cultured at large distances from an oxygen source

Contact Info

Product

Resources

About

NOS2 and COX2 Blockade Limits TNBC Disease Progression and Alters CD8⁺T Cell Spatial Orientation and Density

NOS2 and COX2 Blockade Limits TNBC Disease Progression and Alters CD8⁺T Cell Spatial Orientation and Density