| Purpose: In this study,we examined the specific expression of long noncoding RNA(lnc RNA)in serum exosomes from patients with precancerous gastric lesions to study the effect of serum exosomes on the viability of GES-1 cells in patients with precancerous gastric lesions;all-trans retinoic acid(ATRA)was used to intervene to observe the regulatory effect of ATRA on the viability of GES-1 cells.At the same time,a rat model of precancerous lesions was constructed,and ATRA was used for continuous intervention after successful modeling.By observing the expression of lnc RNA HOXA10 in rat serum exosomes and gastric tissues,combined with pathological findings,ATRA was explored to inhibit the malignant transformation of precancerous lesions by down-regulating the expression of lnc RNA HOXA10.Method: Exosomes were extracted from the serum of patients with gastric precancerous lesions and normal controls,and differentially expressed lnc RNAs were detected by q RT-PCR according to the previous sequencing results of the group.Serum exosomes from patients with gastric precancerous lesions and GES-1 cells were co-cultured in exosome-free serum medium as the experimental group,and 5 ?M ATRA was added to the medium as the experimental intervention group,in which exosomes and retinoic acid concentrations of 0 were the blank control group,and only 5 ?M ATRA was added to the medium as the intervention control group.The changes of cell proliferation,apoptosis and cycle in each group were observed,and the expression of lnc RNA HOXA10 in each group of cells was detected.Three-week-old female wistar rats were purchased and adaptively fed for 7-10 days before the start of the experiment.Afterwards,the rats in the control group were fed with normal diet and free access to water,named as the normal control group(NC).Rats requiring model construction were fed with 0.03% ranitidine diet and drinking water supplemented with 170 ?g/ml monofunctional alkylating agent methylnitronitrosoguanidine(MNNG),named as model group(MOD).After successful modeling,the wistar rats in the model group were randomly divided into groups for corresponding intervention: the positive control group(PC)fed with normal diet and normal drinking water,the continuous intervention group(MNNG)fed with 0.03% ranitidine diet and 170 ?g/ml MNNG free drinking water continuously,the continuous intervention + treatment group(MA)treated with 40 ?g/kg ATRA gavage every day on the basis of the continuous intervention group,and the simple treatment group(ATRA)treated with 40 ?g/kg ATRA gavage every day on the basis of the model control group.After 6 weeks of intervention,the serum and gastric tissues of rats in each group were collected.Rat serum exosomes were extracted,and the expression levels of lnc RNA HOXA10 in rat gastric tissues and serum exosomes were detected by q RT-PCR;the pathological sections of rat hind stomach tissues in each group were stained with HE to observe the pathological changes of gastric mucosa in each group;the ATRA levels in serum and tissues of rats in each group were detected by ELISA kit.Results: GES-1 cells co-cultured with serum exosomes from patients with precancerous gastric lesions had significantly increased cell proliferation activity(P<0.01),reduced apoptosis(P>0.05),and increased lnc RNA HOXA10 expression levels(P>0.05)compared with the blank control group.After treatment with 5 ?M ATRA in the culture medium,the cell viability of each group was significantly decreased(P<0.01),apoptosis was increased(P>0.05),and the proportion of cells in S phase was significantly decreased(P<0.05).The body weight of rats in the NC and MOD group were different after eight weeks of model construction(P<0.05).The pathological changes of gastric mucosa in pylorus were observed after rats in MOD group were randomly sacrificed.The pathological results showed that the gastric mucosa of rats in MOD group showed a tendency of glandular atrophy compared with rats in NC group.The levels of lnc RNA HOXA10 and retinoic acid were measured after grouping intervention in MOD group,and the pathological changes of gastric mucosa were observed in each group.The results showed that the levels of lnc RNA HOXA10 in gastric tissues of MNNG group were significantly increased compared with those of rats in NC group(P<0.05).After retinoic acid intervention,the levels of lnc RNA HOXA10 in gastric tissues of ATRA group were significantly down-regulated compared with those of rats in MNNG group.The q RT-PCR results of serum exosomes showed that the levels of lnc RNA HOXA10 were significantly up-regulated in the PC,MNNG,and MA groups compared with the NC group(P<0.05),and the levels of lnc RNA HOXA10 were significantly down-regulated in the ATRA group compared with the MNNG group after retinoic acid intervention(P<0.05).The results of ELISA showed that ATRA levels in rat serum increased significantly after retinoic acid intervention(P<0.05),and ATRA levels in gastric tissue increased,but retinoic acid increased insignificantly(P>0.05).Histopathological results showed that compared with the NC group,significant glandular atrophy was observed in the gastric body of rats in the PC and MA groups,the gastric mucosal layer disappeared in rats in the MNNG group,and there was no significant difference in the gastric glands between rats in the ATRA group and the NC group.Conclusion: ATRA can inhibit the expression of lnc RNA HOXA10,thereby reducing the promoting effect of lnc RNA HOXA10 on GES-1 cell activity in serum exosomes from patients with precancerous gastric lesions.At the same time,after ATRA intervention,the malignant transformation of gastric precancerous lesions in rats was effectively inhibited,the level of lnc RNA HOXA10 was down-regulated,and the level of ATRA in serum was significantly tall,so we speculated that ATRA could inhibit the malignant transformation of gastric precancerous lesions by inhibiting the abnormal expression of lnc RNA HOXA10. |
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