Activity Changes of the Peptic Lactoferrin Hydrolysate in Human Gastric Cancer AGS Cells in Response to Cu(II) or Mn(II) Addition

Lactoferrin is an interesting bioactive protein in milk and can interact with various metal ions of trace elements such as copper, iron, manganese, and others. In this study, a lactoferrin hydrolysate (LFH) was generated from commercial bovine lactoferrin by protease pepsin, fortified with Cu²⁺ (or Mn²⁺) at two levels of 0.64 and 1.28 (or 0.28 and 0.56) mg/g protein, respectively, and then measured for the resultant bioactivity changes in the well-differentiated human gastric cancer AGS cells. The assaying results indicated that the LFH and Cu/Mn-fortified products had long-term anti-proliferation on the cells, while the treated cells showed DNA fragmentation and increased apoptotic cell proportions. Regarding the control cells, the cells treated with the LFH and especially Cu/Mn-fortified LFH had remarkably up-regulated mRNA expression of caspase-3 and Bax by respective 1.21-3.23 and 2.23-2.83 folds, together with down-regulated mRNA expression Bcl-2 by 0.88-0.96 folds. Moreover, Western-blot assaying results also indicated that the cells exposed to the LFH and Cu/Mn-fortified LFH (especially Mn at higher level) for 24 h had an enhanced caspase-3 expression and increased ratio of Bax/Bcl-2. It can thus be concluded that the used Cu/Mn-addition to the LFH may lead to increased bioactivity in the AGS cells; to be more specific, the two metal ions at the used addition levels could endow LFH with a higher ability to cause cell apoptosis by activating caspase-3 and increasing the Bax/Bcl-2 ratio.

Copper or Manganese Supplementation Endows the Peptic Hydrolysate from Bovine Lactoferrin with Enhanced Activity to Human Gastric Cancer AGS Cells

A lactoferrin hydrolysate (LFH) was generated from bovine lactoferrin by pepsin, mixed with Cu²⁺ and Mn²⁺ at 0.64-1.28 and 0.28-0.56 mg/g protein, respectively; and then their in vitro effects on human gastric cancer AGS cells were assessed. With incubation times of 24 or 48 h, LFH and its Cu²⁺/Mn²⁺ mixtures at 10-30 mg/mL in dose-dependent manner inhibited cell growth; and more, these mixtures showed higher activities than LFH alone. Cell treatments of LFH and the mixtures (25 mg/mL) for 24 h could arrest cell cycle at G0/G1-phase, damage mitochondrial membrane integrity, and induce apoptosis, while the mixtures were also more powerful than LFH to exert these three effects. Higher Cu²⁺/Mn²⁺ supplementation level resulted in higher growth inhibition, cell cycle arrest, mitochondrial membrane potential disruption, and apoptosis induction; furthermore, Mn²⁺ was notable for its higher efficacy than Cu²⁺ to increase these four effects. Western-blot assay results revealed that four apoptosis-related proteins Bad, Bax, cytochrome c, and p53 were up-regulated, and both caspase-3 and caspase-9 also were cleaved and activated; moreover, two autophagy-related proteins LC3-II and cleaved Beclin-1 were down- and up-regulated, respectively. It is thus concluded that Cu²⁺ and especially Mn²⁺ could endow supplemented LFH with increased anti-cancer effects in AGS cells, with two proposed events as enhanced apoptosis induction (via activating apoptosis-related proteins) and autophagy inhibition (via activating autophagy-related proteins).

Effect of the Plastein Reaction in Presence of Extrinsic Amino Acids on the Protective Activity of Casein Hydrolysate against Ethanol-Induced Damage in HHL-5 Cells

Casein hydrolysates (CH) were prepared using papain and modified by the plastein reaction (CH-P) in the presence of extrinsic phenylalanine (CH-P-Phe) or tryptophan (CH-P-Trp). The in vitro protective activity of CH and its modified products against ethanol-induced damage in HHL-5 cells was investigated. The results showed that the modification by the plastein reaction reduced the amino group content of CH. However, the modification by the plastein reaction in the presence of extrinsic amino acids could enhance the antioxidant, proliferative, cell cycle arresting, and anti-apoptosis activity of CH. Biological activities of CH and its modified products in the HHL-5 cells varied depending on the hydrolysate concentration (1, 2, and 3 mg/mL) and treatment time (24, 48, and 72 h). Generally, higher biological activities were found after cell treatment with CH or its modified products at concentration of 2 mg/mL for 48 h compared to other treatments. In addition, CH modified in the presence of tryptophan (CH-P-Trp) showed higher biological activity than that modified in the presence of phenylalanine (CH-P-Phe). Based on the obtained results, it can be concluded that casein hydrolysates with enhanced biological activity and potential health benefits can be produced by papain and the plastein reaction with the incorporation of extrinsic amino acids.

Effect of Cu/Mn-Fortification on In Vitro Activities of the Peptic Hydrolysate of Bovine Lactoferrin against Human Gastric Cancer BGC-823 Cells

Bovine lactoferrin hydrolysate (BLH) was prepared with pepsin, fortified with Cu2+ (Mn2+) 0.64 and 1.28 (0.28 and 0.56) mg/g protein, and then assessed for their activity against human gastric cancer BGC-823 cells. BLH and the four fortified BLH products dose- and time-dependently had growth inhibition on the cells in both short- and long-time experiments. These samples at dose level of 25 mg/mL could stop cell-cycle progression at the G0/G1-phase, damage mitochondrial membrane, and induce cell apoptosis. In total, the fortified BLH products had higher activities in the cells than BLH alone. Moreover, higher Cu/Mn fortification level brought higher effects, and Mn was more effective than Cu to increase these effects. In the treated cells, the apoptosis-related proteins such as Bad, Bax, p53, cytochrome c, caspase-3, and caspase-9 were up-regulated, while Bcl-2 was down-regulated. Caspase-3 activation was also evidenced using a caspase-3 inhibitor, z-VAD-fmk. Thus, Cu- and especially Mn-fortification of BLH brought health benefits such as increased anti-cancer activity in the BGC-823 cells via activating the apoptosis-related proteins to induce cell apoptosis.

[Diagnostic value of endobronchial ultrasonography with guide-sheath combined with virtual bronchoscopy navigation in peripheral lung cancer]

Objective: To explore the diagnostic value and safety of endobronchial ultrasonography with guide-sheath (EBUS-GS) combined with virtual bronchoscopy navigation (VBN) in peripheral lung cancer. Methods: Between Dec. 2015 to Dec. 2016, patients with pulmonary solitary nodule suspected of early lung cancer on computed tomography (CT) in Department of Respiratory, Tangdu Hospital, Fourth Military Medical University were enrolled for this study. The patients underwent EBUS-GS transbronchoscopic lung biopsy (TBLB) with or without VBN. The visibility rate, diagnostic yield, influencing factors, the operation time and complications were evaluated in the 2 groups. The data were compared using independent sample t test or chi-squared test. Results: A total of 134 patients were enrolled and completed this study. Among them 74 were males and 60 were females. There were 64 cases in the group of EBUS-GS with VBN (VBNA), and 70 in the group without VBN (NVBNA). The visibility rate and diagnosis rate of VBNA group were 87.5% (56/64) and 78.1% (50/64), respectively. The mean time of operation and confirming the target lesions were (25±5), (5.8±1.3) min, respectively. The visibility rate and diagnosis rate of NVBNA group were 81.4%(57/70) and 75.7%(53/70), respectively. The mean time of operation and confirming the target lesions were (27±6), (9.8±1.5)min .There was no significant difference in the visibility rate and diagnosis rate between the 2 groups (χ(2)=0.933, P=0.334; χ(2)=0.109, P=0.838). There was no significant difference in the mean operation time between the 2 groups(t=0.633, P=0.524). But the time of confirming the target lesions between the 2 groups was statistically different (t=17.41, P<0.01). EBUS-GS-TBLB was well tolerated. No severe complications such as pneumothorax or chest pain were observed. There were 3 patients in the VBNA group and 7 patients in the NVBNA group experiencing a small amount of biopsy site bleeding. The incidence of complications did not differ between the 2 groups(χ(2)=1.366, P=0.330). Conclusions: VBN could not improve the diagnostic yield of EBUS-GS. However, it could shorten the time needed to confirm the target lesions and did not increase the incidence of EBUS-GS complications, indicating that EBUS-GS with VBN was a safe and effective method.