Biology subjects

Vidotto, T.

Publications and source records attributed to Vidotto, T..

6 recordsLinked to original sources

bioRxiv2026

TFE3 fusions drive expression of CD44 and SPP1 in Translocation Renal Cell Carcinoma

Xp11.2 translocation RCC [Xp11.2 tRCC]) is an underdiagnosed and aggressive subtype of RCC with few specific or targeted therapies. The transmembrane glycoprotein CD44 is an emerging target in many advanced malignancies, and with its ligand OPN (SPP1), is a crucial driver of cancer progression, stemness, metastasis, and immune suppression. Here we show that common TFE3-fusions [ including SFPQ-TFE3, PRCC-TFE3, ASPSCR1-TFE3, and NONO-TFE3] are associated with upregulated expression of CD44 and SPP1, as observed in multiple human and murine bulk transcriptomic studies and a murine tRCC snRNA-Seq dataset. CD44 and/or SPP1 protein expression were also upregulated in murine models of transgenic tRCC kidneys and urine specimens, patient-derived cell lines and human tRCC cases, by immunoblotting and/or IHC. Transient deletion of CD44 was associated with profound and specific suppression of tRCC cell line growth, with decreased mTOR signaling. These data suggest that CD44 and/or SPP1 may potentially drive tumorigenesis in tRCC.

cancer biology↗

bioRxiv2024

SFPQ-TFE3 gene fusion reciprocally regulates mTORC1 activity and induces lineage plasticity in a novel mouse model of renal tumorigenesis

The MiT/TFE family gene fusion proteins, such as SFPQ-TFE3, drive both epithelial (eg, translocation renal cell carcinoma, tRCC) and mesenchymal (eg, perivascular epithelioid cell tumor, PEComa) neoplasms with aggressive behavior. However, no prior mouse models for SFPQ-TFE3-related tumors exist and the mechanisms of lineage plasticity induced by this fusion remain unclear. Here, we demonstrate that constitutive murine renal expression of human SFPQ-TFE3 using Ksp Cadherin-Cre as a driver disrupts kidney development leading to early neonatal renal failure and death. In contrast, post-natal induction of SFPQ-TFE3 in renal tubular epithelial cells using Pax8 ERT-Cre induces infiltrative epithelioid tumors, which morphologically and transcriptionally resemble human PEComas. As seen in MiT/TFE fusion-driven human tumors, SFPQ-TFE3 expression is accompanied by the strong induction of mTORC1 signaling, which is partially amino acid-sensitive and dependent on increased SFPQ-TFE3-mediated RRAGC/D transcription. Remarkably, SFPQ-TFE3 expression is sufficient to induce lineage plasticity in renal tubular epithelial cells, with rapid down-regulation of the critical PAX2/PAX8 nephric lineage factors and tubular epithelial markers, and concomitant up-regulation of PEComa differentiation markers in transgenic mice, human cell line models and human tRCC. Pharmacologic or genetic inhibition of mTOR signaling downregulates expression of the SFPQ-TFE3 fusion protein and rescues nephric lineage marker expression and transcriptional activity in vitro. These data provide evidence of a potential epithelial cell-of-origin for TFE3-driven PEComas and highlight a reciprocal role for SFPQ-TFE3 and mTOR in driving lineage plasticity in the kidney, expanding our understanding of the pathogenesis of MiT/TFE-driven tumors.

cancer biology↗

bioRxiv2022

Pan-genomic analysis shows hemizygous PTEN loss tumors are associated with immune evasion and poor outcome

In tumors, somatic mutations of the PTEN suppressor gene are associated with advanced disease, chemotherapy resistance, and poor survival. PTEN loss of function may occur by inactivating mutation, by deletion, either affecting one copy (hemizygous loss) leading to reduced gene expression or loss of both copies (homozygous) with expression absent. Various murine models have shown that minor reductions in PTEN protein levels strongly influence tumorigenesis. Most PTEN biomarker assays dichotomize PTEN (i.e. presence vs. absence) ignoring the role of one copy loss. We performed a PTEN copy number analysis of 9,793 TCGA cases from 30 different tumor types. There were 419 (4.28%) homozygous and 2484 (25.37%) hemizygous PTEN losses. Hemizygous deletions led to reduced PTEN gene expression, accompanied by increased levels of instability and aneuploidy across tumor genomes. Outcome analysis of the pan-cancer cohort showed that losing one copy of PTEN reduced survival to comparable levels as complete loss, and was associated with transcriptomic changes controlling immune response and the tumor microenvironment. Immune cell abundances were significantly altered for PTEN loss, with changes in head and neck, cervix, stomach, prostate, brain, and colon more evident in hemizygous loss tumors. These data suggest that reduced expression of PTEN in tumors with hemizygous loss leads to tumor progression and influences anticancer immune response pathways.

cancer biology↗

bioRxiv2021

Sexual dimorphism in outcomes of non-muscle invasive bladder cancer: a role of CD163+ M2 macrophages, B cells and PD-L1 immune checkpoint.

Non-muscle invasive bladder cancer (NMIBC) is significantly more common in men than women. However, female patients with NMIBC often present with more aggressive disease and do not respond as well to immunotherapy treatments. We hypothesized that sexual dimorphism in the tumor immune microenvironment (TIME) may contribute to the inferior clinical outcomes observed in female patients. To test this hypothesis, we interrogated the expression patterns of genes associated with specific immune cell types and immune regulatory pathways using tumor whole transcriptome profiles from male (n=357) and female (n=103) patients with NMIBC. High-grade tumors from female patients exhibited significantly increased expression of CD40, CTLA4, PDCD1, LAG3 and ICOS immune checkpoint genes. Based on the significant differences in expression profiles of these genes and the cell types that most commonly express these in the TIME, we evaluated the density and spatial distribution of CD8+Ki67+ (activated cytotoxic T cells), FoxP3+ (regulatory T cells), CD103+ (tissue resident T cells), CD163+ (M2-like tumor associated macrophages), CD79a+ (B cells), PD-L1+ (Programmed-Death Ligand-1) and PD-1+ cells using multiplexed immunofluorescence in an independent cohort of 332 patient tumors on a tissue microarray (n=259 males and n=73 females). Tumors from female patients showed significantly higher infiltration of CD163+ macrophages and PD-L1+ cells compared to tumors from male patients. Notably, increased infiltration of CD163+ macrophages and CD79a+ B cells independently associated with decreased recurrence free survival. Not only do these results have the potential to inform the rational utilization of immunomodulatory therapies based on the TIME of both male and female patients with NMIBC, these novel findings highlight the necessity of considering sexual dimorphism in the design of future immunotherapy trials.

immunology↗

bioRxiv2020

Transcriptional landscape of PTEN loss in primary prostate cancer

PTEN is the most frequently lost tumor suppressor in primary prostate cancer (PCa) and its loss is associated with aggressive disease. However, the transcriptional changes associated with PTEN loss in PCa have not been described in detail. Here, we applied a meta-analysis approach, leveraging two large PCa cohorts with experimentally validated PTEN and ERG status, to derive a transcriptomic signature of PTEN loss, while also accounting for potential confounders due to ERG rearrangements. Strikingly, the signature indicates a strong activation of both innate and adaptive immune systems upon PTEN loss, as well as an expected activation of cell-cycle genes. Moreover, we made use of our recently developed FC-R2 expression atlas to expand this signature to include many non-coding RNAs recently annotated by the FANTOM consortium. With this resource, we analyzed the TCGA-PRAD cohort, creating a comprehensive transcriptomic landscape of PTEN loss in PCa that comprises both the coding and an extensive non-coding counterpart.

cancer biology↗

bioRxiv2019

Chemotherapy induced immunogenic cell death alters response to exogenous activation of STING pathway and PD-L1 immune checkpoint blockade in a syngeneic murine model of ovarian cancer.

Poor response to platinum/taxane-based chemotherapy has remained a major hurdle in the management of high grade serous carcinoma of the ovary (HGSC). Recurrent HGSC is often treated with liposomal doxorubicin as a second line chemotherapy. Unfortunately, HGSC patients have not benefited from immunotherapies targeting the PD-1/PD-L1 immune checkpoint axis. In a pre-clinical study evaluating the efficacy of a \"Stimulator of Interferon Genes\" (STING) agonist, we demonstrated the synergistic potential of STING pathway activation in enhancing response to carboplatin chemotherapy and sensitization to PD-1 immune checkpoint blockade (ICB). Since carboplatin and doxorubicin exhibit distinct immunogenic cell death (ICD) inducing potential, we investigated the chemotherapy specific effect in the magnitude of response to exogenous STING pathway activation. Immunocompetent C57/BL6 mice were implanted with ID8-Trp53-/- cells followed by treatment with carboplatin or doxorubicin. Towards rationalized addition of STING agonist with or without PD-L1 blockade, we first determined the expression of 60 known ICD associated genes at an early time point following the initial treatment with carboplatin or doxorubicin with or without STING agonist. Doxorubicin treated tumours showed significantly higher expression of ICD genes, Cxcl10, Cd274, Isg15, Psmb9 and Calr. Expression changes were further amplified following the addition of STING agonist. Significantly higher expression of Cxcl10 and Isg15 were observed in the doxorubicin + STING agonist treated mice compared to carboplatin + STING agonist combination. Interestingly, Ccl5 gene expression was higher in the tumours from carboplatin or carboplatin and STING agonist combination treated mice compared to those treated with doxorubicin. Plasma cytokine analysis showed distinct profiles of CXCL10, CCL5, MCP-1 and IL6 post treatment with each chemotherapy type. Doxorubicin monotherapy treated mice showed significantly longer overall survival compared to their carboplatin counterparts with further increases following addition of either STING agonist or PD-L1 ICB. However, despite the stronger ICD inducing ability of doxorubicin, overall survival of mice treated with carboplatin + STING agonist + PD-L1 ICB was the longest. Findings from our pre-clinical study provide novel insights for rationalized combinations of immune sensitizing agents such as STING pathway activators to improve response of HGSC patients to chemotherapy and ICB in the primary and recurrent settings.

cancer biology↗