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Lysine ß-hydroxybutyrylation (Kbhb) is a post-translational modification induced by the ketogenic diet (KD), a diet showing therapeutic effects on multiple human diseases. Little is known how cellular processes are regulated by Kbhb. Here we show that protein Kbhb is strongly affected by the KD through a multi-omics analysis of mouse livers. Using a small training dataset with known functions, we developed a bioinformatics method for the prediction of functionally important lysine modification sites (pFunK), which revealed functionally relevant Kbhb sites on various proteins, including aldolase B (ALDOB) Lys108. KD consumption or ß-hydroxybutyrate supplementation in hepatocellular carcinoma cells increases ALDOB Lys108bhb and inhibits the enzymatic activity of ALDOB. A Kbhb-mimicking mutation (p.Lys108Gln) attenuates ALDOB activity and its binding to substrate fructose-1,6-bisphosphate, inhibits mammalian target of rapamycin signalling and glycolysis, and markedly suppresses cancer cell proliferation. Our study reveals a critical role of Kbhb in regulating cancer cell metabolism and provides a generally applicable algorithm for predicting functionally important lysine modification sites.

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Individuals with rotating and night shift work are highly susceptible to developing metabolic disorders such as obesity and diabetes. This is primarily attributed to disruptions in the circadian rhythms caused by activities and irregular eating habits. Time-restricted feeding (tRF) limits the daily eating schedules and has been demonstrated to markedly improve several metabolic disorders. Although an intricate relationship exists between tRF and circadian rhythms, the underlying specific mechanism remains elusive. We used a sleep disruption device for activity interference and established a model of circadian rhythm disorder in mice with different genetic backgrounds. We found that circadian rhythm disruption led to abnormal hormone secretion in the gut and elevated insulin resistance. tRF improved metabolic abnormalities caused by circadian rhythm disruption, primarily by restoring the gut hormone secretion rhythm and activating brown fat thermogenesis. The crucial function of brown fat in tRF was confirmed using a mouse model with brown fat removal. We demonstrated that chenodeoxycholic acid (CDCA) effectively improved circadian rhythm disruption-induced metabolic disorders by restoring brown fat activation. Our findings demonstrate the potential benefits of CDCA in reversing metabolic disadvantages associated with irregular circadian rhythms.

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Natural protoberberine alkaloids were first identified and characterized as potent, selective and cellular active lysine specific demethylase 1 (LSD1) inhibitors. Due to our study, isoquinoline-based tetracyclic scaffold was identified as the key structural element for their anti-LSD1 activity, subtle changes of substituents attached to the core structure led to dramatic changes of the activity. Among these protoberberine alkaloids, epiberberine potently inhibited LSD1 (IC50 = 0.14 ± 0.01 µM) and was highly selective to LSD1 over MAO-A/B. Furthermore, epiberberine could induce the expression of CD86, CD11b and CD14 in THP-1 and HL-60 cells, confirming its cellular activity of inducing acute myeloid leukemia (AML) cells differentiation. Moreover, epiberberine prolonged the survival of THP-1 cells bearing mice and inhibited the growth of AML cells in vivo without obvious global toxicity. These findings give the potential application of epiberberine in AML treatment, and the isoquinoline-based tetracyclic scaffold could be used for further development of LSD1 inhibitors.

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AIMS: Programmed death ligand 1 (PD-L1, CD274) has been reported to be expressed abnormally in many cancers, nevertheless, effect of PD-L1 on tumor cells remains unclear, especially in gastric cancer (GC). This study aimed to investigate the role of PD-L1 in metastasis and differentiation in GC. MAIN METHODS: Immunohistochemistry was performed on 237 paired GC tissues. shPD-L1 cells were generated by lentivirus shRNA solution and PD-L1-overexpressing cells were constructed by pcDNA3.1. Expression of PD-L1 and E-cadherin in GC cells were detected by western blot. KEY FINDINGS: PD-L1 expression was significantly lower in GC than that in adjacent normal tissues, especially in poorly differentiated and metastatic GC, but was positively correlated to survival time of patients. Moreover, PD-L1 ablation could decrease E-cadherin expression, promote cell migration and wound repair ability. In turn, overexpression of PD-L1 increased E-cadherin expression and inhibited wound repair ability. At the same time, All-trans retinoic acid (ATRA), which has the properties of pro-differentiation and inhibition of invasion and metastasis, upregulated the expression of PD-L1 and E-cadherin. SIGNIFICANCE: These findings not only identify PD-L1 may have a positive role for the treatment of GC, but also implicate that ATRA combined PD-L1 antibody drugs may enhance anti-tumor Immunity in GC.

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EGFR tyrosine kinase inhibitor (EGFR-TKI) has been used successfully in clinic for the treatment of solid tumors. In the present study, we reported the discovery of WS-157 from our in-house diverse compound library, which was validated to be a potent and selective EGFR-TKI. WS-157 showed excellent inhibitory activities against EGFR (IC50 = 0.81 nmol/L), EGFR[d746-750] (IC50 = 1.2 nmol/L) and EGFR[L858R] (IC50 = 1.1 nmol/L), but was less effective or even inactive against other nine kinases. WS-157 also displayed excellent antiproliferative activities against a panel of human cancer cell lines, and exhibited the ability to reduce colony formation and wound healing the same as gefitinib. We found that WS-157 upon oral administration showed better anti-tumor activity in A431 bearing xenograft mouse models compared to gefitinib. In addition, WS-157 showed better intestinal absorption than gefitinib and had favorable pharmacokinetic properties and microsomal metabolic stability in different species. These studies indicate that WS-157 has strong antitumor activity in vitro and in vivo, and could be used for the development of anti-lung cancer agent targeting EGFR.

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Sanggenon O (SO) is a Diels-Alder type adduct extracted fromMorus alba, which has been used for its anti-inflammatory action in the Oriental medicine. However, whether it has regulatory effect on human cancer cell proliferation and what the underlying mechanism remains unknown. Here, we found that SO could significantly inhibit the growth and proliferation of A549 cells and induce its pro-apoptotic action through a caspase-dependent pathway. It could also impair the mitochondria which can be reflected by mitochondrial membrane permeabilization. Besides, SQSTM1 up-regulation and autophagic flux measurement demonstrated that exposure to SO led to autophagosome accumulation, which plays a protective role in SO-treated cells. In addition, knocking down of LC3B increased SO triggered apoptotic cell rates. These results indicated that SO has great potential as a promising candidate combined with autophagy inhibitor for the treatment of NSCLC. In conclusion, our results identified a novel mechanism by which SO exerts potent anticancer activity.

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