The bone marrow stroma capacity to confer resistance to leukemia cells from Ara-C treatment as a prognostic factor for overall survival in AML

Autor: Sergio Vargas-Salas, Bruno Nervi, Vivianne Torres, Juan Carlos Roa, Sabrina Muñiz-Muñoz, Carolina Bizama, Patricia Macanas-Pirard, Francisco Melo, Viviana P. Montecinos, Daniel Ernst, Richard Broekhuizen, Romina Coronado
Rok vydání: 2019
Předmět:
Zdroj: Journal of Clinical Oncology. 37:e18500-e18500
ISSN: 1527-7755
0732-183X
Popis: e18500 Background: The interaction of acute myeloid leukemia (AML) with the bone marrow stroma (BMS) determines a protective microenvironment that favors leukemia development and resistance to chemotherapy. We developed an in vitro platform to study leukemia and stroma interaction, and showed that BMS secretes soluble factors protecting AML cells from Ara-C-induced apoptosis, which correlated with clinical patient outcomes. Methods: BMS from AML patients and healthy donors were cultured to perform chemo-sensitivity studies with Ara-C on THP-1 cells. A Resistance Factor was calculated (RF = IC50 stroma conditioned medium (CM)/IC50 control medium) to classify BMS as “protective” (PS: confers chemo-resistance) or “non-protective” (NPS: does not confer chemo-resistance). Characterization of myofibroblasts in BMS cultures was performed by WB. Quantification of cytokines from primary BMS CM was performed by Luminex. The differential expression of epithelial-mesenquimal-like (EMT-like) and stem cell-markers in THP-1 cells incubated with primary BMS CM was measured by qPCR. Results: We recruited 90 AML patients and 10 healthy BM donors. AML cohort showed 31 patients with PS and 59 patients with NPS. PS patients had a significant poor overall survival (OS) compared with NPS patients (44% versus 70% OS in 2.5 years, median survival 7.3 months versus 20.7 months, HR 2.36). The stroma from healthy BM donors did not confer resistance to THP-1 cells. BMS in both, PS and NPS have activated myofibroblasts and analysis of cytokine expression showed differential expression between groups. THP-1 cells incubated with PS showed significant expression of EMT- and stem cell-markers like Twist, Vimentin, CD44 and CD34 compared to THP-1 cells incubated with NPS and control medium. Conclusions: The capacity of the BMS from AML patients to modulate chemoresistance is a strong prognostic factor for OS, and PS patients have a worst OS compared with NPS patients. Stroma from healthy donors has a NPS phenotype. We propose that the leukemia is capable of educating the stroma to acquire secondarily the capacity to confer resistance to leukemia cells to favor tumor progression and chemoresistance.
Databáze: OpenAIRE