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Lepland, J.

Publications and source records attributed to Lepland, J..

2 recordsLinked to original sources

Targeting mitochondria mitigates chemotherapy-induced bone marrow dysfunction

Chemotherapy has revolutionized cancer treatment but its long-term impact on healthy tissues, particularly the rapidly dividing hematopoietic system, remains a significant concern. We show that the chemotherapeutic agent 5-fluorouracil (5-FU) causes significant long-term defects of the hematopoietic system that mimics ageing, including myeloid lineage skewing and hematopoietic stem cell (HSC) dysfunction. Importantly, chemotherapy exposed HSCs remain in an inflammatory state coupled with mitochondrial dysfunction, both of which are implicated in ageing and MDS development. Remarkably, five days of MitoQ treatment fully reversed 5-FU-induced myeloid skewing and caused significant recovery of HSC transcriptome and function in a stable manner. Thus, our results demonstrate that repeated chemotherapy induces long-term bone marrow dysfunction driven by metabolically unfit HSCs that can be pharmacologically rescued. This work opens up novel avenues to explore supportive treatment for patients undergoing any type of myelo-ablative chemotherapy. HighlightsO_LICommonly used chemotherapy drugs cause stable lineage-specific cytopenias despite recovery of total blood counts. C_LIO_LI5-FU-induced hematopoietic dysfunction phenocopies premature hematopoietic ageing. C_LIO_LIChemotherapy-induced changes stem from HSCs that are self-renewal competent but differentiation incompetent. C_LIO_LIMitochondrial-targeted treatment rescues 5-FU-induced myeloid bias through correction of HSC transcriptome and function. C_LI

cell biology↗

C/EBPB-dependent Adaptation to Palmitic Acid Promotes Stemness in Hormone Receptor Negative Breast Cancer

Epidemiological studies have established a positive association between obesity and the incidence of postmenopausal breast cancer. Moreover, it is known that obesity promotes stem cell-like properties of breast cancer cells. However, the cancer cell-autonomous mechanisms underlying this correlation are not well defined. Here we demonstrate that obesity-associated tumor formation is driven by cellular adaptation rather than expansion of pre-existing clones within the cancer cell population. While there is no correlation with specific mutations, cellular adaptation to obesity is governed by palmitic acid (PA) and leads to enhanced tumor formation capacity of breast cancer cells. This process is governed epigenetically through increased chromatin occupancy of the transcription factor CCAAT/enhancer-binding protein beta (C/EBPB). Obesity-induced epigenetic activation of C/EBPB regulates cancer stem-like properties by modulating the expression of key downstream regulators including CLDN1 and LCN2. Collectively, our findings demonstrate that obesity drives cellular adaptation to PA drives tumor initiation in the obese setting through activation of a C/EBPB dependent transcriptional network. SignificanceCellular adaptation to obesity-induced palmitic acid drives tumor initiation through activation of a C/EBPB-dependent transcriptional network. This highlights a cell-autonomous mechanistic connection between obesity and postmenopausal hormone receptor negative breast cancer.

cancer biology↗