scholarly journals Deconvolution of the immunological contexture of mouse tumors with multiplexed immunohistochemistry

Author(s):  
Ileana S. Mauldin ◽  
Natasha D. Sheybani ◽  
Samuel J. Young ◽  
Richard J. Price ◽  
Craig L. Slingluff
Keyword(s):  
2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii218-ii218
Author(s):  
Patricia Yee ◽  
Yiju Wei ◽  
Soo Yeon Kim ◽  
Tong Lu ◽  
Cynthia Lawson ◽  
...  

Abstract Tumor necrosis indicates poor prognoses in many cancers, including glioblastomas (GBMs). Although thought to result from chronic ischemia, the underlying nature and mechanisms driving the involved cell death remain obscured by lack of animal models recapitulating the extent of necrosis in human GBMs. The molecular and clinical heterogeneity of GBMs adds further complexity. Not all GBMs contain necrosis. Mesenchymal (MES)-GBM, the subtype correlated with worst prognosis and highest treatment resistance, is most closely associated with necrosis. MES-GBM exhibits hyperactivity of transcriptional coactivator with PDZ-binding motif (TAZ), a Hippo tumor suppressive pathway effector whose expression in human GBMs predicts short survival. To elucidate mechanisms driving GBM necrosis, we devised a novel orthotopic mouse model recapitulating human MES-GBM phenotypically and histopathologically by expressing a constitutively-active TAZ mutant (TAZ4SA) in three human GBM cell lines (LN229, U87, and LN18) lacking MES signatures (GBM4SA). GBM4SA mice lived significantly shorter than mice implanted with GBMvector or mutant TAZ unable to bind its downstream effector, TEAD (GBM4SA-S51A). Extensive (≥30% of tumor volume) necrosis was present in GBM4SA mice but not GBMvector or GBM4SA-S51A. In GBM4SA tumors, neutrophils coincide with necrosis temporally and spatially. Neutrophil depletion dampens necrosis. Neutrophils isolated from mouse tumors killed co-cultured tumor cells. Neutrophils induce iron-dependent accumulation of lipid hydroperoxides within tumor cells by transferring myeloperoxidase-containing granules into tumor cells. Inhibiting myeloperoxidase suppresses neutrophil-induced tumor cytotoxicity. Intratumoral glutathione peroxidase 4 (GPX4) overexpression or acyl-CoA synthetase 4 (ACSL4) depletion diminishes necrosis and aggressiveness of tumors. Human GBM analysis indicates neutrophils and ferroptosis are associated with necrosis and predict poor survival. Together, we propose that certain tumor damage(s) during early tumor progression (i.e. ischemia) recruits neutrophils to damaged tissue and results in a positive feedback loop, amplifying GBM necrosis development. We show GBM necrosis involves neutrophil-triggered ferroptosis and reveal an unprecedented pro-tumorigenic role of ferroptosis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matthew R. Swiatnicki ◽  
Eran R. Andrechek

AbstractThe E2F family of transcription factors is important for many cellular processes, from their canonical role in cell cycle regulation to other roles in angiogenesis and metastasis. Alteration of the Rb/E2F pathway occurs in various forms of cancer, including breast cancer. E2F1 ablation has been shown to decrease metastasis in MMTV-Neu and MMTV-PyMT transgenic mouse models of breast cancer. Here we take a bioinformatic approach to determine the E2F1 regulated genomic alterations involved in the metastatic cascade, in both Neu and PyMT models. Through gene expression analysis, we reveal few transcriptome changes in non-metastatic E2F1−/− tumors relative to transgenic tumor controls. However investigation of these models through whole genome sequencing found numerous differences between the models, including differences in the proposed tumor etiology between E2F1−/− and E2F1+/+ tumors induced by Neu or PyMT. For example, loss of E2F1 within the Neu model led to an increased contribution of the inefficient double stranded break repair signature to the proposed etiology of the tumors. While the SNV mutation burden was higher in PyMT mouse tumors than Neu mouse tumors, there was no statistically significant differences between E2F WT and E2F1 KO mice. Investigating mutated genes through gene set analysis also found a significant number of genes mutated in the cell adhesion pathway in E2F1−/− tumors, indicating this may be a route for disruption of metastasis in E2F1−/− tumors. Overall, these findings illustrate the complicated nature of uncovering drivers of the metastatic process.


2021 ◽  
pp. 106636
Author(s):  
C. Ankjærgaard ◽  
A.Z. Johansen ◽  
M.M.K. von Staffeldt ◽  
C.E. Andersen ◽  
D.H. Madsen ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3366
Author(s):  
Aneline Dolet ◽  
Rita Ammanouil ◽  
Virginie Petrilli ◽  
Cédric Richard ◽  
Piero Tortoli ◽  
...  

Multispectral photoacoustic imaging is a powerful noninvasive medical imaging technique that provides access to functional information. In this study, a set of methods is proposed and validated, with experimental multispectral photoacoustic images used to estimate the concentration of chromophores. The unmixing techniques used in this paper consist of two steps: (1) automatic extraction of the reference spectrum of each pure chromophore; and (2) abundance calculation of each pure chromophore from the estimated reference spectra. The compared strategies bring positivity and sum-to-one constraints, from the hyperspectral remote sensing field to multispectral photoacoustic, to evaluate chromophore concentration. Particularly, the study extracts the endmembers and compares the algorithms from the hyperspectral remote sensing domain and a dedicated algorithm for segmentation of multispectral photoacoustic data to this end. First, these strategies are tested with dilution and mixing of chromophores on colored 4% agar phantom data. Then, some preliminary in vivo experiments are performed. These consist of estimations of the oxygen saturation rate (sO2) in mouse tumors. This article proposes then a proof-of-concept of the interest to bring hyperspectral remote sensing algorithms to multispectral photoacoustic imaging for the estimation of chromophore concentration.


1971 ◽  
Vol 252 (2) ◽  
pp. 357-368 ◽  
Author(s):  
Kunimi Kikuchi ◽  
Hisako Kikuchi ◽  
Shigeru Tsuiki
Keyword(s):  

1936 ◽  
Vol 28 (3) ◽  
pp. 512-521
Author(s):  
M. J. Eisen

2021 ◽  
Author(s):  
Robin Loesch ◽  
Stefano Caruso ◽  
Valerie Paradis ◽  
Cecile Godard ◽  
Angelique Gougelet ◽  
...  

Background and aims: One-third of hepatocellular carcinomas (HCCs) have mutations that activate the β-catenin pathway with mostly CTNNB1 mutations. Mouse models using Adenomatous polyposis coli (Apc) loss-of-functions (LOF) are widely used to mimic β-catenin-dependent tumorigenesis. Considering the low prevalence of APC mutations in human HCCs we aimed to generate hepatic tumors through CTNNB1 exon 3 deletion (βcatΔex3) and to compare them to hepatic tumors with Apc LOF engineered through a frameshift in exon 15 (Apcfs-ex15). Methods: We used hepatic-specific and inducible Cre-lox mouse models as well as a hepatic-specific in vivo CRISPR/Cas9 approach using AAV vectors, to generate Apcfs-ex15 and βcatΔex3 hepatic tumors harboring activation of the β-catenin pathway. Tumors generated by the Cre-lox models were analyzed phenotypically using immunohistochemistry and were selected for transcriptomic analysis using RNA-sequencing. Mouse RNAseq data were compared to human RNAseq data (normal tissues (8), HCCs (48) and hepatoblastomas (9)) in an integrative analysis. Tumors generated via CRISPR were analyzed using DNA sequencing and immunohistochemistry. Results: Mice with βcatΔex3 alteration in hepatocytes developed liver tumors. Generated tumors were indistinguishable from those arising in Apcfs-ex15 mice. Both Apcfs-ex15 and βcatΔex3 mouse models induced two phenotypically distinct tumors (differentiated or undifferentiated). Integrative analysis of human and mouse tumors showed that mouse differentiated tumors are close to human well differentiated CTNNB1-mutated tumors, while undifferentiated ones are closer to human mesenchymal hepatoblastomas, and are activated for YAP signaling. Conclusion: Apcfs-ex15 and βcatΔex3 mouse models similarly induce tumors transcriptionally close to either well differentiated β-Catenin activated human HCCs or mesenchymal hepatoblastomas.


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