ABSTRACT
Objective To study the influence of let-7b on cell proliferation and aerobic glycolysis of human melanoma cell A375.Methods Transfect A375 cell line with hsa-let-7b oligonucleotide or antisense.Glucose and lactate in medium were determined by spectrophotometry at 24 h and 48 h time point after transfection.The cell proliferation was determined by methylthiazol tetrazolium (MTT) assay.Results Over expression of let-7b in melanoma cell reduced cell proliferation notably,compared to the other groups by MTT(P ＜0.05).However,the glucose consumption and lactate production differences were not observed during 24 h or 48 h ( P ＞ 0.05 ),the blank control group transformed about 57％ and 43％ glucose to lactate during 24 h and 48 h.Conclusions Melanoma cell line A375 has notably aerobic glycolysis hallmark,let-7b could inhibit proliferation of melanoma cell line A375,but it may has no influence on glucose metabolism.
ABSTRACT
BACKGROUND: Previous studies demonstrated that exercise modes easily cause hepatic injury and result in hepatic apoptosis. However, the mechanisms remain undear. OBJECTIVE: To observe the hepatic apoptosis, changes of hepatic glycogen, NO, and calcium levels following establishing various exhaustive exercise models.DESIGN, TIME AND SETTING: The randomized, controlled, animal experiment of ultrastructure observation was performed at the Physical Education School of Hunan Normal University, and Department of Histology and Embryology, Central South University, from January 2004 to December 2006.MATERIALS: Thirty male Sprague Dawley rats, aged 8 weeks, weighing (219.2+19.5) g, were randomly divided into control, middle intensity exercise and high intensity exercise groups according to Berdford models, with 10 animals in each group. METHODS: Rats in the exercise group were performed 3 days treadmill training with speed of 10 m/min, in running platform with 0°, followed by 3 days rest. After that, rats in the middle intensity exercise group were training with initial velocity of 10 m/min for 12 minutes, and than gradually increased exercise load to 19.3 m/min, until rats were exhausted. In the high intensity exercise groups,the initial velocity was 26.8 m/min, until rats were exhausted. The training was performed once per day for 30 successive days.There was no exercise training in the control group.MAIN OUTCOME MEASURES: The levels of hepatic glycogen, NO, Ca~(2+), and hepatic apoptosis were measured after exercise.RESULTS: Totally 30 rats were included in the final analysis. All rats finished exercise without resistance. The exhaustive exercise time in the middle intensity exercise group was (234.60+60.05) min, which was (92.40±34.61) min in the high intensity exercise group. Compared to the control group, the contents of hepatic glycogen and NO were decreased, while Ca~(2+) level and hepatic apoptosis index were increased in 2 exercise groups (P < 0.05, P < 0.01 ), in particular notable in the middle intensity exercise group (P < 0.05).CONCLUSION: Both middle and high intensity exhaustive exercise can lead to hepatic apoptosis, which may be the great accumulation of Ca~(2+) in mitochondrion and the fower contents of liver glycogen and NO content. The changes may be associated with exhaustive exercise time.