MicroRNA-138 negatively regulates non-small cell lung cancer cells through the interaction with cyclin D3.

Previous studies demonstrate that microRNA-138 (miR-138) is critical in non-small cell lung cancer (NSCLC) regulation. We further explored the molecular mechanism of miR-138 in NSCLC. Lentivirus was used to upregulate miR-138 in NSCLC cell lines H460 and SPC-A1 cells. Previously known effects of miR-138 upregulation on NSCLC, proliferation, cell cycle division, and cisplatin sensitivity were examined in H460 and SPC-A1 cells. Moreover, previously unknown effect of miR-138 upregulation on NSCLC migration was also examined in H460 and SPC-A1 cells. A new miR-138 downstream target, cyclin D3 (CCND3), was assessed by dual-luciferase reporter assay and quantitative real-time PCR (qRT-PCR). CCND3 was then ectopically overexpressed in H460 and SPC-A1 cells. The effects of forced overexpression of CCND3 on miR-138-induced NSCLC regulations were further examined by proliferation, cell cycle, cisplatin sensitivity, and migration assays, respectively. Lentivirus-induced miR-138 upregulation inhibited NSCLC proliferation and cell cycle division, in line with previous findings. Moreover, we found that miR-138 upregulation had other anti-tumor effects, such as increasing cisplatin sensitivity and reducing cancer migration, in H460 and SPC-A1 cells. Luciferase assay and qRT-PCR showed that CCND3 was directly targeted by miR-138. Forced overexpression of CCND3 in H460 and SPC-A1 cells reversed the anti-tumor effects of miR-138 upregulation on cancer cell growth, cell cycle, cisplatin sensitivity, and migration. Our study revealed novel anti-cancer effects of miR-138 upregulation in NSCLC, as well as its new molecular target of CCND3.

[Influence of chronic intermittent hypoxia on sympathetic nerve activity in rats and effect of the antioxidant Tempol].

OBJECTIVE: To study the role of sympathetic nerve activity during the development of hypertension resulting from chronic intermittent hypoxia, and whether or not elevated sympathetic nerve activity is related to oxidative stress, and to investigate the preventive effect and possible mechanism of Tempol. METHODS: Forty-eight male Wistar rats were randomly divided into 6 groups of 8 each, including normoxic control group (NC), intermittent hypoxia group (IH) and 4 treatment groups (IHT1, IHT2, IHN1, IHN2). Among the treatment groups, IHT1, IHT2 groups were treated with 10% Tempol 100 mg × kg(-1)× d(-1) by intraperitoneal injection before exposed to IH and on day 28 after exposed to IH respectively, while IHN1 and IHN2 groups were treated with NS as controls. RESULT: There was no statistic difference in artery systolic blood pressure (SBP) between IH group, IHN1 group [(114 ± 6) mm Hg, 1 mm Hg = 0.133 kPa], and IHN2 group [(128 ± 6) mm Hg, P < 0.05] at the end of 6(th) week. SBP in the all IH groups was significantly elevated compared with NC group (P < 0.05) and the baseline SBP (P < 0.05) except of the group IHT1. SBP in the 2 tempol treatment groups was lower than the NS groups [(138 ± 10) mm Hg, both P < 0.05], while SBP of IHT2 group was higher than the IHT1 group (P < 0.01). No significant changes were found in the NC group. There were no statistic difference of NE and E in plasma and MDA in adrenal gland tissues between IH groups, IHN1 group and IHN2 group. The levels in NE and E and MDA in the 2 tempol treatment groups were lower than the NS groups (P < 0.05 or P < 0.01), but those in the IHT2 group were higher than the NC group (P < 0.05 or P < 0.01) and IHT1 groups (P < 0.05 or P < 0.01). No significant difference were found between IHT1 group and NC group. CONCLUSION: CIH could generate ROS by causing oxidative stress, which results in elevated sympathetic nerve activity. This may be one of the important mechanisms for CIH-induced hypertension. Tempol may be useful for prevention and treatment of OSAS-induced hypertension.

[Hepatic injury in rats exposed to chronic intermittent hypoxia and the effect of tempol].

OBJECTIVE: To investigate the mechanism of liver injury in rats exposed to chronic intermittent hypoxia (CIH) and to investigate the effect of tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl or 4-hydroxy-TEMPO). METHODS: A CIH animal model of rats was established to mimic the intermittent hypoxia/re-oxygenation (IH/ROX) of obstructive sleep apnea syndrome in humans. Thirty-two healthy male Wistar rats were randomly assigned to 4 groups: conventional intermittent hypoxia group (CIH group), intermittent hypoxia Tempol treatment group (CIH + T group), intermittent hypoxia normal saline matched group (CIH + NS group), and normoxic control group (NC group), with 8 rats in each group. The frequency of every CIH group was 30 times/h, and the minimum oxygen concentration was 5%. After the experiment, sections of liver were stained with hematoxylin-eosin (HE) and the levels of nuclear factor-kappaB (NF-κB), glutathione peroxidase (GSH-PX) and malondialdehyde (MDA) in rat liver homogenate were measured. RESULTS: Liver histology revealed that the CIH group and the CIH + NS group showed hepatocellular swelling with rarefaction of the cytoplasm, hyperchromatosis and hepatocellular membrane disruption, but the liver histology of the CIH + T group and the NC group was normal. Compared with the NC group, the levels of NF-κB and MDA in the CIH group [(12.4 ± 2.0) ng/g, (101 ± 22) µmol/g] and the CIH + NS group [(12.2 ± 1.9) ng/g, (99 ± 18)µmol/g] were increased (all P < 0.05), but the activities of GSH-PX [(88 ± 17) U/mg, (90 ± 15) U/mg] were decreased (all P < 0.05). Compared with the CIH + NS group and the CIH group, the activity of GSH-PX in the CIH + T group [(181 ± 29) U/mg] was increased (P < 0.05), but the levels of NF-κB [(7.8 ± 1.3) ng/g] and MDA [(59 ± 10) µmol/g] were decreased (all P < 0.05). The levels of GSH-PX and MDA in the CIH + T group were not significantly different compared to the NC group (P were 0.242, 0.177 respectively), but the level of NF-κB in the CIH + T group was higher than that in the NC group (P < 0.05). The levels of NF-κB, GSH-PX, and MDA in the CIH + NS group were not significantly different as compared to those in the CIH group (all P > 0.05). The level of NF-κB was correlated negatively with GSH-PX, but positively with MDA (r = -0.754, 0.689, respectively, all P < 0.01) CONCLUSIONS: CIH could cause rat liver injury through oxidative stress and activating the proinflammatory transcription factors of NF-κB. Tempol could prevent CIH-induced liver injury through scavenging ROS by its anti-oxidative effect.