Symmans, W. F. | Search bioRxiv

bioRxiv2024

An annotated biobank of triple negative breast cancer patient-derived xenografts featuring treatment-naive and longitudinal samples throughout neoadjuvant chemotherapy

Triple negative breast cancer (TNBC) that fails to respond to neoadjuvant chemotherapy (NACT) can be lethal. Developing effective strategies to eradicate chemoresistant disease requires experimental models that recapitulate the heterogeneity characteristic of TNBC. To that end, we established a biobank of 92 orthotopic patient-derived xenograft (PDX) models of TNBC from the tumors of 75 patients enrolled in the ARTEMIS clinical trial (NCT02276443) at MD Anderson Cancer Center, including 12 longitudinal sets generated from serial patient biopsies collected throughout NACT and from metastatic disease. Models were established from both chemosensitive and chemoresistant tumors, and nearly 30% of PDX models were capable of lung metastasis. Comprehensive molecular profiling demonstrated conservation of genomes and transcriptomes between patient and corresponding PDX tumors, with representation of all major transcriptional subtypes. Transcriptional changes observed in the longitudinal PDX models highlight dysregulation in pathways associated with DNA integrity, extracellular matrix interactions, the ubiquitin-proteasome system, epigenetics, and inflammatory signaling. These alterations reveal a complex network of adaptations associated with chemoresistance. This PDX biobank provides a valuable resource for tackling the most pressing issues facing the clinical management of TNBC, namely chemoresistance and metastasis.

cancer biology↗

bioRxiv2021

Acquisition of cancer stem cell properties during EMT requires cell division

Cancer cells acquire stem cell and mesenchymal properties during epithelial-to-mesenchymal transition (EMT), facilitating metastasis and chemoresistance [1-6]. In this study, we find that mammary epithelial cells quickly develop mesenchymal phenotype in response to EMT-inducing signals; however, acquiring stemness takes several days and always requires a preceding mesenchymal program. In addition, we observe that carcinoma cells, over a period of time, switch their cell division from symmetrical differentiated type to symmetrical self-renewal type. Importantly, epithelial cells can gain mesenchymal properties without undergoing cell division, but cell disivion is vital for these cells to gain stem cell properties during EMT. The EMT-induced stemness signature (SC-sig) is capable of predicting progression-free and overall-survival of breast cancer patients but not the EMT-induced mesenchymal signature (M-sig). Collectively, our findings demonstrate that the use of mesenchymal markers alone is insufficient to identify tumors with metastatic and chemoresistance potential and emphasize that the markers of EMT-induced stem cell program are central for clinical prediction. Most importantly, our data, for the first time, demonstrate that acquisition of stem cell properties during EMT depends on cell division but not the mesenchymal program.

cell biology↗