Highlights d PKM1 promotes tumor growth cell intrinsically in some contexts d PKM1 activates glucose catabolism without interfering with biosynthetic pathways d PKM1-dependent autophagy/mitophagy contributes to malignancy d Expression of PKM1, but not PKM2, is sufficient to support SCLC cell proliferation
Somatic mutations in the gene encoding the catalytic subunit of protein phosphatase 6 (Ppp6c) have been identified in malignant melanoma and are thought to function as a driver in B-raf- or N-ras-driven tumorigenesis. To assess the role of Ppp6c in carcinogenesis, we generated skin keratinocyte-specific Ppp6c conditional knockout mice and performed two-stage skin carcinogenesis analysis. Ppp6c deficiency induced papilloma formation with 7,12-dimethylbenz (a) anthracene (DMBA) only, and development of those papillomas was significantly accelerated compared with that seen following DMBA/TPA (12-O-tetradecanoylphorbol 13-acetate) treatment of wild-type mice. NF-κB activation either by tumor necrosis factor (TNF)-α or interleukin (IL)-1β was enhanced in Ppp6c-deficient keratinocytes. Overall, we conclude that Ppp6c deficiency predisposes mice to skin carcinogenesis initiated by DMBA. This is the first report showing that such deficiency promotes tumor formation in mice.
Ethylene glycol monomethyl ether (EGME), sulpiride, and atrazine are known ovarian toxicants, which increase progesterone (P4) secretion and induce luteal cell hypertrophy following repeated administration. The aim of this study was to define the pathways by which these compounds exerted their effects on the ovary and hypothalamic-pituitary-gonadal (HPG) axis. In the ovary, changes in the steroidogenic activity of new and old corpora lutea (CL) were addressed. EGME (300 mg/kg), sulpiride (100 mg/kg), or atrazine (300 mg/kg) were orally given daily for four times from proestrus to diestrus in normal cycling rats. Treatment with all chemicals significantly increased serum P4 levels, and EGME as well as sulpiride induced increases in prolactin (PRL) levels. In new CL, at both the gene and the protein levels, all three chemicals upregulated the following steroidogenic factors: scavenger receptor class B type I, steroidogenic acute regulatory protein, P450 cholesterol side-chain cleavage, and 3β-hydroxysteroid dehydrogenase (HSD) and downregulated the luteolytic gene, 20α-HSD. Coadministration of EGME and bromocriptine, a D2 agonist, completely inhibited PRL but not P4 secretion. Additionally, steroidogenic factor expression levels were upregulated, and 20α-HSD level was downregulated in new CL. These results suggest that EGME both directly and indirectly stimulates P4 production in luteal cells, whereas sulpiride elevates P4 through activation of PRL secretion in the pituitary. Atrazine may directly activate new CL by stimulating steroidogenic factor expressions. The present study suggests that multiple pathways mediate the effects of EGME, sulpiride, and atrazine on the HPG axis and luteal P4 production in female rats in vivo.
The clinical manifestations of COVID‐19 vary broadly, ranging from asymptomatic infection to acute respiratory failure and death. But the predictive biomarkers for characterizing the variability are still lacking. Since emerging evidence indicates that extracellular vesicles (EVs) and extracellular RNAs (exRNAs) are functionally involved in a number of pathological processes, we hypothesize that these extracellular components may be key determinants and/or predictors of COVID‐19 severity. To test our hypothesis, we collected serum samples from 31 patients with mild COVID‐19 symptoms at the time of their admission for discovery cohort. After symptomatic treatment without corticosteroids, 9 of the 31 patients developed severe/critical COVID‐19 symptoms. We analyzed EV protein and exRNA profiles to look for correlations between these profiles and COVID‐19 severity. Strikingly, we identified three distinct groups of markers (antiviral response‐related EV proteins, coagulation‐related markers, and liver damage‐related exRNAs) with the potential to serve as early predictive biomarkers for COVID‐19 severity. As the best predictive marker, EV COPB2 protein, a subunit of the Golgi coatomer complex, exhibited significantly higher abundance in patients remained mild than developed severe/critical COVID‐19 and healthy controls in discovery cohort (AUC 1.00 (95% CI: 1.00‐1.00)). The validation set included 40 COVID‐19 patients and 39 healthy controls, and showed exactly the same trend between the three groups with excellent predictive value (AUC 0.85 (95% CI: 0.73‐0.97)). These findings highlight the potential of EV COPB2 expression for patient stratification and for making early clinical decisions about strategies for COVID‐19 therapy.
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