Effect of overexpression of hypoxia-inducible factor-1α induced by hyperoxia in vivo in LNCaP tumors on tumor growth rate

Objective:To study effect of overexpression of hypoxia-inducible factor-1_α induced by hyperoxia in vivo in LNCaP tumors on tumor growth rate.Methods:The prostate cancer LNCaP cells were inoculated in the abdomen of mice.All the mice were randomly placed in the gas chamber with different oxygen content.The groups were divided as follows:twelve mice in hypoxia group,sixteen mice in normoxia group,ten mice in hyperoxia group.After 28 d of treatment,the mice were weighed,the blood samples were taken from the left ventricle,and the tumor was isolated and weighed.Tumor growth,angiogenesis and vascularization,HIF-1_α expression and intracellular signal transduction molecules expression in each group of xenografts were detected and analyzed by using Western blotting and immunofluorescence and determination of hemoglobin.Results:Comparison of the growth of xenografts in each group showed that,the xenografts growth of hypoxia group was more quickly than that of normoxia group.The difference was statistically significant(P=0.Q04).The difference in xenografts growth between hyperoxia group compared and normoxia group was not statistically significant(P>0.05).The expressions of HIF-1_α,VEGF and VEGF-R of xenografts in hyperoxia group were significantly higher than those of normoxia group(P<0.05).The expression of HIF-1_α of xenografts in hypoxia group and normoxia group were similar.The blood growth rate of xenografts in hypoxia group(170%) was significantly higher than that of normoxia group(40%)(P<0.05).The expression of Nrf2 of xenografts in hyperoxia group was significantly higher than that of normoxia group(P<0.05).Conclusions:When hyperoxia induces the overexpression of HIF-1_α in LNCaP tumor,it will not affect tumor growth.It provides a new ideas and theoretical basis for the clinical treatment of prostate cancer.

Long non-coding RNA small nucleolar RNA host gene 6 aggravates pancreatic cancer through upregulation of far upstream element binding protein 1 by sponging microRNA-26a-5p

Background:Pancreatic cancer(PC)is a highly deadly malignancy with few effective therapies.We aimed to unmask the role that long non-coding RNA small nucleolar RNA host gene 6(SNHG6)plays in PC cells by targeting far upstream element binding protein 1(FUBP1)via microRNA-26a-5p(miR-26a-5p).Methods::SNHG6 expression was predicted by bioinformatics,followed by verification via reverse transcription quantitative polymerase chain reaction.Then,the interactions among SNHG6,miR-26a-5p,and FUBP1 were detected through online software analysis,dual luciferase reporter assay and RNA pull-down.After that,cells were treated with different small interfering RNAs and/or mimic to determine the interactions among SNHG6,miR-26a-5p,and FUBP1 and their roles in PC cells.Finally,the role of SNHG6 in tumor growth in vivo was evaluated by measuring the growth and weight of transplanted tumors in nude mice.A t-test,one-way and two-way analysis of variance were used for data analysis.Results::Compared with that in normal tissues,SNHG6 was highly expressed in PC tissues(1.00±0.05 vs.1.56±0.06,t=16.03,P<0.001).Compared with that in human pancreatic duct epithelial cells(HPDE6-C7),SNHG6 showed the highest expression in PANC-1 cells(1.00±0.06 vs.3.87±0.13,t=34.72,P<0.001)and the lowest expression in human pancreatic cancer cells(MIAPaCa-2)(1.00±0.06 vs.1.41±0.07,t=7.70,P=0.0015).Compared with the levels in the si-negative control group,SNHG6(0.97±0.05 vs.0.21±0.06,t=16.85,P<0.001),N-cadherin(0.74±0.05 vs.0.41±0.04,t=8.93,P<0.001),Vimentin(0.55±0.04 vs.0.25±0.03,t=10.39,P<0.001),andβ-catenin(0.62±0.05 vs.0.32±0.03,t=8.91,P<0.001)were decreased,while E-cadherin(0.65±0.06 vs.1.36±0.07,t=13.34,P<0.001)was increased after SNHG6 knockdown or miR-26a-5p overexpression,accompanied by inhibited cell proliferation,migration,and invasion.SNHG6 overexpression exerted the opposite effects.SNHG6 upregulated FUBP1 expression by sponging miR-26a-5p.Silencing SNHG6 blocked the growth of PC in vivo.Conclusion::Silencing SNHG6 might ameliorate PC through inhibition of FUBP1 by sponging miR-26a-5p,thus providing further supporting evidence for its use in PC treatment.