Daniela Ungureanu

ROR1-PI3K/AKT signaling drives adaptive resistance to cell cycle blockade in TP53 mutated ovarian cancer

Abstract Drug resistance remains a major challenge to durable responses in ovarian cancer, the fifth leading cause of cancer-related death among women. In this study, we developed long-term resistant (lt-res, several months) pre-clinical models of two drugs inducing mitotic arrest in TP53 -mutated cells: adavosertib (ADA), an investigational WEE1 inhibitor targeting the DNA damage response and currently evaluated in clinical trials, and paclitaxel (PTX), a widely used chemotherapeutic agent in cancer care targeting microtubules. Through integrated multi-omics functional profiling, we identify a shared PI3K/AKT-regulated signaling node that governs drug adaptation across all lt-res models. This node modulates the activity of DNA-damage responses and genotoxic stress to toggle between two adaptive states: activated PI3K/AKT driving a proliferative “fast-bypass” program with sustained cell cycle progression and mitotic evasion, or reduced PI3K/AKT signaling initiating a “slow-repair” state characterized by DNA damage checkpoint engagement, replication slowdown, and increased drug efflux. Notably, upregulation of receptor tyrosine kinases, such as ROR1, was observed in both ADA and PTX lt-res models with activated PI3K/AKT signaling. Targeting ROR1 with zilovertamab-vedotin, a monoclonal antibody-drug conjugate, resulted in enhanced cytotoxicity, demonstrating a new approach against recurrent drug-resistant ovarian cancer.

A multiplex single-cell RNA-Seq pharmacotranscriptomics pipeline for drug discovery

Abstract The gene-regulatory dynamics governing drug responses in cancer are yet to be fully understood. Here, we report a pipeline capable of producing high-throughput pharmacotranscriptomic profiling through live-cell barcoding using antibody–oligonucleotide conjugates. This pipeline combines drug screening with 96-plex single-cell RNA sequencing. We show the potential of this approach by exploring the heterogeneous transcriptional landscape of primary high-grade serous ovarian cancer (HGSOC) cells after treatment with 45 drugs, with 13 distinct classes of mechanisms of action. A subset of phosphatidylinositol 3-OH kinase (PI3K), protein kinase B (AKT) and mammalian target of rapamycin (mTOR) inhibitors induced the activation of receptor tyrosine kinases, such as the epithelial growth factor receptor (EGFR), and this was mediated by the upregulation of caveolin 1 (CAV1). This drug resistance feedback loop could be mitigated by the synergistic action of agents targeting PI3K–AKT–mTOR and EGFR for HGSOC with CAV1 and EGFR expression. Using this workflow could enable the personalized testing of patient-derived tumor samples at single-cell resolution.

Multiomics characterization implicates PTK7 in ovarian cancer EMT and cell plasticity and offers strategies for therapeutic intervention

AbstractMost patients with ovarian cancer (OC) are diagnosed at a late stage when there are very few therapeutic options and a poor prognosis. This is due to the lack of clearly defined underlying mechanisms or an oncogenic addiction that can be targeted pharmacologically, unlike other types of cancer. Here, we identified protein tyrosine kinase 7 (PTK7) as a potential new therapeutic target in OC following a multiomics approach using genetic and pharmacological interventions. We performed proteomics analyses upon PTK7 knockdown in OC cells and identified novel downstream effectors such as synuclein-γ (SNCG), SALL2, and PP1γ, and these findings were corroborated in ex vivo primary samples using PTK7 monoclonal antibody cofetuzumab. Our phosphoproteomics analyses demonstrated that PTK7 modulates cell adhesion and Rho-GTPase signaling to sustain epithelial-mesenchymal transition (EMT) and cell plasticity, which was confirmed by high-content image analysis of 3D models. Furthermore, using high-throughput drug sensitivity testing (525 drugs) we show that targeting PTK7 exhibited synergistic activity with chemotherapeutic agent paclitaxel, CHK1/2 inhibitor prexasertib, and PLK1 inhibitor GSK461364, among others, in OC cells and ex vivo primary samples. Taken together, our study provides unique insight into the function of PTK7, which helps to define its role in mediating aberrant Wnt signaling in ovarian cancer.