• Asian Pacific Journal of Cancer Prevention
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• 제14권6호
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• pp.3725-3728
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• 2013

Background: The mammalian target of rapamycin (mTOR) /RPS6KB1 activation has recently been implicated in tumour development, but its role in lung cancer remains unclear. The aim of this study was to explore the role of mTOR/RPS6KB1 signaling pathway in non-small-cell lung cancer (NSCLC). Methods: Immunohistochemistry was performed to assess the expression of phosphorylated mammalian target of rapamycin (p-mTOR) and its downstream ribosomal phosphorylated RPS6KB1 (p-RPS6KB1) in NSCLC patients. We also analyzed p-mTOR/p-RPS6KB1 protein expression in 45 fresh NSCLC tissues using Western blotting. Results: The expression level of p-mTOR and p-RPS6KB1 was significantly higher in NSCLC tumor specimens than that in adjacent noncancerous normal lung tissues (P<0.01). p-mTOR expression correlated with p-RPS6KB1. Furthermore, high expression level of p-mTOR or p-RPS6KB1 in NSCLC was associated with a shorter overall survival (both P<0.01). Multivariate analysis indicated high level of p-mTOR expression was an independent prognostic factor (HR=2.642, 95%CI 1.157-4.904, p=0.002). Conclusions: p-mTOR and p-RPS6KB1 could be useful prognostic markers for NSCLC.

• Journal of Animal Science and Technology
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• 제63권5호
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• pp.1126-1141
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• 2021

Recent evidence has shown that methionine (Met) supplementation can improve milk protein synthesis under hyperthermia (which reduces milk production). To explore the mechanism by which milk protein synthesis is affected by Met supplementation under hyperthermia, mammary alveolar (MAC-T) cells were incubated at a hyperthermic temperature of 42℃ for 6 h in media with different concentrations of Met. While the control group (CON) contained a normal amino acid concentration profile (60 ㎍/mL of Met), the three treatment groups were supplemented with Met at concentrations of 10 ㎍/mL (MET70, 70 ㎍/mL of Met), 20 ㎍/mL (MET80, 80 ㎍/mL of Met), and 30 ㎍/mL (MET90,90 ㎍/mL of Met). Our results show that additional Met supplementation increases the mRNA and protein levels of BCL2 (B-cell lymphoma-2, an anti-apoptosis agent), and decreases the mRNA and protein levels of BAX (Bcl-2-associated X protein, a pro-apoptosis agent), especially at an additional supplementary concentration of 20 ㎍/mL (group Met80). Supplementation with higher concentrations of Met decreased the mRNA levels of Caspase-3 and Caspase-9, and increased protein levels of heat shock protein (HSP70). The total protein levels of the mechanistic target of rapamycin (mTOR) and the mTOR signalling pathway-related proteins, AKT, ribosomal protein S6 kinase B1 (RPS6KB1), and ribosomal protein S6 (RPS6), increased with increasing Met supplementation, and peaked at 80 ㎍/mL Met (group Met80). In addition, we also found that additional Met supplementation upregulated the gene expression of αS1-casein (CSN1S1), β-casein (CSN2), and the amino acid transporter genes SLC38A2, SLC38A3 which are known to be mTOR targets. Additional Met supplementation, however, had no effect on the gene expression of κ-casein (CSN3) and solute carrier family 34 member 2 (SLC34A2). Our results suggest that additional Met supplementation with 20 ㎍/mL may promote the synthesis of milk proteins in bovine mammary epithelial cells under hyperthermia by inhibiting apoptosis, activating the AKT-mTOR-RPS6KB1 signalling pathway, and regulating the entry of amino acids into these cells.