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Mann, B. E.

Publications and source records attributed to Mann, B. E..

2 recordsLinked to original sources

A Novel ex-vivo platform for personalized treatment in metastatic ovarian cancer.

The lack of functional precision models that recapitulate the pathology and structure/function relationship of advanced ovarian cancer (OC) within an appropriate anatomic setting constitutes a hurdle on the path to developing more reliable therapies and matching those therapies with the right patients. Here, we developed and characterized an Organotypic Mesentery Membrane Culture (OMMC) model as a novel ex-vivo platform where freshly resected human patient OC tumor tissue or established cell lines are seeded directly atop living intact rat mesenteric membranes, rapidly engraft, and enable functional assessment of treatment response to FDA-approved standard care of treatment as single and combination drug therapies within just five days. This study showed successful survival of dissected mesentery tissue, survival and engraftment of tumor cells and patient tumor tissue seeded on OMMCs, mesentery-tumor cell interaction, and quantification of tumor response to treatment and off-target toxicity. Summarized "drug sensitivity scores", using a multi-parametric algorithm, were also calculated for each patients treatment response, enabling us to suggest the most effective therapeutic option. Finally, we compared drug sensitivity results from patient tumor tissue on OMMCs to matched outcomes of individual patients in the clinic and identified positive correlations in drug sensitivity, beginning to validate the functionality of OMMCs as a functional predictor of treatment response. Summary sentenceWe have successfully developed and characterized a novel ex-vivo platform for personalized treatment of metastatic ovarian cancer.

cancer biology↗

Trans-Lesion Synthesis and Mismatch Repair Pathway Crosstalk Defines Chemoresistance and Hypermutation Mechanisms in Glioblastoma

Almost all Glioblastoma (GBM) are either intrinsically resistant to the chemotherapeutical drug temozolomide (TMZ) or acquire therapy-induced mutations that cause chemoresistance and recurrence. The genome maintenance mechanisms responsible for GBM chemoresistance and hypermutation are unknown. We show that the E3 ubiquitin ligase RAD18 (a proximal regulator of TLS) is activated in a Mismatch repair (MMR)-dependent manner in TMZ-treated GBM cells, promoting post-replicative gap-filling and survival. An unbiased CRISPR screen provides a new aerial map of RAD18-interacting DNA damage response (DDR) pathways deployed by GBM to tolerate TMZ genotoxicity. Analysis of mutation signatures from TMZ-treated GBM reveals a role for RAD18 in error-free bypass of O6mG (the most toxic TMZ-induced lesion), and error-prone bypass of other TMZ-induced lesions. Our analyses of recurrent GBM patient samples establishes a correlation between low RAD18 expression and hypermutation. Taken together we define novel molecular underpinnings for the hallmark tumorigenic phenotypes of TMZ-treated GBM.

cancer biology↗