Biology subjects

Lin, M.-L.

Publications and source records attributed to Lin, M.-L..

2 recordsLinked to original sources

bioRxiv2021

PPAR-delta acts as a metabolic master checkpoint for metastasis in pancreatic cancer

SO_SCPLOWUMMARYC_SCPLOWIn pancreatic cancer, emerging evidence suggests that PPAR-{delta} overexpression is associated with tumor progression and metastasis, but a mechanistic link is still missing. Here we now show that PPAR-{delta} acts as the integrating upstream regulator for the metabolic rewiring, which is preceding the subsequent initiation of an invasive/metastatic program. Specifically, paracrine and metabolic cues regularly found in the metastasis-promoting tumor stroma consistently enhance, via induction of PPAR-{delta} activity, the glycolytic capacity and reserve of pancreatic cancer cells, respectively, accompanied by decreased mitochondrial oxygen consumption. Consequently, genetic or pharmacological inhibition of PPAR-{delta} results in reduced invasiveness and metastasis. Mechanistically, PPAR-{delta} acts by shifting the MYC/PGC1A balance towards MYC, enhancing metabolic plasticity. Targeting MYC similarly prevents the metabolic switch and subsequent initiation of invasiveness. Therefore, our data demonstrate that PPAR-{delta} is a key initiator for the metabolic reprogramming in pancreatic cancer, thereby acting as a checkpoint for the phenotypic change towards invasiveness. These findings provide compelling evidence for a novel treatment strategy to combat pancreatic cancer progression.

cancer biology↗

bioRxiv2021

Clonal dynamics of normal hepatocyte expansions in homeostatic human livers and their association with the biliary epithelium

The majority of human liver research is disease-focused such that far less is known of cellular dynamics within normal human liver. We have leveraged cytochrome c oxidase deficiency as a marker of clonal hepatocyte populations in such tissues. We demonstrate these populations commonly associate with portal tracts and lineage-trace hepatocytes with cholangiocytes, indicating the presence of a bipotential common ancestor at this niche. We also observe rare periportal SOX9+ hepatocytes progenitor candidates in our human tissues. To understand clonal expansion dynamics, we measured methylation diversity and identified mtDNA variants by next-generation sequencing within spatially-defined clonal hepatocyte patches. We coupled our sequencing with mathematical modelling and Bayesian inference to compare spatial patterns of mtDNA variants under assumptions with or without faster expansion from a portal-associated niche. These datasets support the existence of a periportal progenitor niche and indicate that clonal patches slowly expand, perhaps due to acute environmental stimuli, then quiesce. These findings crucially contribute to our understanding of hepatocyte dynamics in normal human liver and provide a baseline for understanding how such dynamics may be modulated in diseased liver.

cell biology↗