Biology subjects

Roman-Roman, S.

Publications and source records attributed to Roman-Roman, S..

3 recordsLinked to original sources

bioRxiv2022

Multi-omics comparison of malignant and normal uveal melanocytes reveals novel molecular features of uveal melanoma.

Uveal Melanoma (UM) is a rare cancer resulting from transformation of melanocytes residing in the uveal tract. Integrative analysis has identified four molecular and clinical subsets in UM. To improve our molecular understanding of UM we performed extensive multi-omics characterization comparing two aggressive UM patient-derived xenograft models with normal choroidal melanocytes, including DNA optical mapping, specific histone modifications, and DNA topology analysis by Hi-C. Our gene expression and cytogenetic analyses suggest that genomic instability is a hallmark of UM. We also identified a recurrent deletion in the BAP1 promoter resulting in loss of expression and associated with high risk of metastases in UM patients. Hi-C revealed chromatin topology changes associated with up-regulation of PRAME, an independent prognostic biomarker in UM and potential therapeutic target. Our findings illustrate how multi-omics approaches can improve the understanding of tumorigenesis and reveals two novel mechanisms of gene expression dysregulation in UM.

genomics↗

bioRxiv2021

Patient-derived zebrafish xenograft models reveal ferroptosis as a fatal and druggable weakness in metastatic uveal melanoma

Uveal melanoma (UM) is the most common intraocular melanoma, derived from transformed melanocytes of the uvea. Although treatment of primary UM is usually successful, there is a high risk (up to 50%) of liver metastasis with negligible long-term survival. There are currently no reproducible patient-derived animal models that faithfully recapitulate the latter stages of metastatic dissemination of UM, hindering the discovery of curative treatments. To overcome this problem and to accelerate the development of new metastatic UM treatments, we developed a patient-derived zebrafish xenograft (zf-PDX) model, using spheroid cultures generated from metastatic and primary UM tissues. Engrafted UM cells derived from these spheroid cultures give rise to metastatic lesions and recapitulate the molecular features of UMs and their potential drug sensitivity. Importantly, harnessing this versatile model, we reveal a high sensitivity of circulating UM cells to ferroptosis induction in vivo by Erastin and RSL3. Our findings are further corroborated by supportive analysis of patient data implicating ferroptosis as a new, and druggable, target for the treatment of metastatic UM patients, specifically in those with BAP1 loss in the tumor.

cancer biology↗

bioRxiv2021

PRMT1 regulates EGFR and Wnt signaling pathways and is a promising target for combinatorial treatment of breast cancer

Identifying new therapeutic strategies for triple-negative breast cancer (TNBC) patients is a priority as these patients are highly prone to relapse after chemotherapy. Here, we found that protein arginine methyltransferase 1 (PRMT1) is highly expressed in all breast cancer subtypes. Its depletion decreases cell survival by inducing DNA damage and apoptosis in various breast cancer cell lines. Transcriptomic analysis and chromatin immunoprecipitation revealed that PRMT1 regulates the epidermal growth factor receptor (EGFR) and the Wnt signaling pathways, reported to be activated in TNBC. The enzymatic activity of PRMT1 is also required to stimulate the canonical Wnt pathway. Recently developed type I PRMT inhibitors decrease breast cancer cell proliferation and show anti-tumor activity in a TNBC xenograft model. These inhibitors display synergistic interactions with some chemotherapies used to treat TNBC patients, as well as the EGFR inhibitor, erlotinib. Therefore, targeting PRMT1 in combination with drugs used in the clinic may improve current treatments for TNBC patients. SignificanceThis study highlights the requirement of PRMT1 for breast cancer cell survival and demonstrates the potential of targeting type I PRMTs in combination with chemotherapies in triple-negative breast cancer.

cancer biology↗