Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal malignancies because it is often diagnosed at a late disease stage and has a poor response rate to currently available treatments. Therefore, it is critical to develop new therapeutic approaches that will enhance the efficacy and reduce the toxicity of currently used therapies. Here we aimed to evaluate the therapeutic potential and mechanisms of action for piperlongumine (PL), an alkaloid from long pepper, in PDAC models. We postulated that PL causes PDAC cell death through oxidative stress and complements the therapeutic efficacy of chemotherapeutic agents in PDAC cells. First, we determined that PL is one of the most abundant alkaloids with antitumor properties in the long pepper plant. We also showed PL in combination with gemcitabine, a chemotherapy agent used to treat advanced pancreatic cancer, reduced tumor weight and volume compared to vehicle-control and individual treatments. Further, biochemical analysis, including RNA sequencing and immunohistochemistry, suggested that the antitumor activity of PL was associated with decreased cell proliferation, induction of cell cycle arrest, and oxidative stress-induced cell death. Moreover, we identified that c-Jun N-terminal kinase (JNK) inhibition blocks PL-induced cell death, translocation of Nrf2, and transcriptional activation of HMOX1 in PDAC. Finally, high-throughput drug and CRISPR screenings identified potential targets that could be used in combination with PL to treat PDAC cells. Collectively, our data suggests that cell cycle regulators in combination with PL might be an effective approach to combat pancreatic cancer. / NIH

During the past few decades, the landscape of available therapeutic interventions for cancer treatment has widely expanded, boosted mainly by immunotherapy progress and the precision oncology paradigm. The extensive use of pre-clinical models in cancer research has led to the discovery of new effective treatment options for patients. Despite the notable advancements, some cancer types have found minor benefits from the use of precision-oncology interventions. Characterized by a heterogeneous molecular landscape, bladder cancer is one of the most frequent cancer types in which standard-of- care treatments involve surgical operations accompanied by broad-spectrum chemotherapy. My research stems from the need for precision oncology interventions in bladder cancer and specifically focuses on the development of computational frameworks to guide the discovery of new therapeutic opportunities. This work first introduces the exploration of possible therapeutic interventions in 9p21.3 depleted bladder tumors through the analysis of an in-house large High-Content Drug Screening that tested 2,349 compounds. By combining cell count changes and morphological quantitative features extracted from fluorescence images, we nominate cytarabine as a putative candidate eliciting specific cytotoxic effects in an engineered 9p21.3 depleted bladder cancer model compared to an isogenic wild-type clone. Focusing on the development of computational methodologies to nominate robust context-specific vulnerabilities, I further describe PRODE (PROtein interactions informed Differential Essentiality), an analytical workflow that integrates protein-protein interaction data and Loss of Function screening data. I extensively tested PRODE against the most commonly used and alternative methodologies and demonstrated its superior performance when classifying reference essential and context-essential genes collected from experimental and literature sources. Furthermore, we applied PRODE to a real case scenario, seeking essential genes selectively in the context of HER2+ Breast Cancer tumors. Finally, I report the computational analyses performed on Patient-Derived Organoids (PDOs) established from a bladder cancer cohort. PDOs are demonstrated as informative models when assessing the therapeutic sensitivity of patients to drugs. Overall, this research highlights novel precision-oncology applications by ad-hoc computational analyses that address key open technical and biological challenges in the field of bladder cancer and beyond.