摘要
为探讨 RARβ受体介导全反式视黄酸 ( ATRA)抑制胃癌细胞生长的作用机理 ,用 Northern印迹测定 RARβ m RNA表达水平 ,脂质体介导的转染方法将含有 RARβ基因的表达载体转染MKN- 45细胞并稳定表达 ,MTT和软琼脂集落形成等实验测定细胞生长速率和生长状态 ,氯霉素乙酰转移酶活性 ( CAT)测定视黄酸应答元件βRARE的转录活性以及 AP- 1 ( activator protein- 1 )活性 .RARβ在 ATRA敏感细胞株 MGC80 - 3、BGC- 82 3和 SGC- 790 1中表达 ,而在 ATRA抗性细胞株 MKN- 45中不表达 .当 RARβ基因转染 MKN- 45细胞时 ,细胞变为 ATRA敏感 ,由此导致ATRA抑制 MKN- 45细胞生长和软琼脂集落形成 .ATRA可以加强诱导 MGC80 - 3、BGC- 82 3和SGC- 790 1细胞βRARE的转录活性 ,但对 MKN- 45细胞影响不大 ,不能抑制细胞 AP- 1活性 .当RARβ基因转染 MKN- 45细胞后 ,ATRA则能够诱导细胞 βRARE的转录活性 ,并抑制细胞的 AP-1活性 .RARβ表达与 ATRA抑制胃癌细胞生长密切相关 .ATRA诱导 βRARE转录活性和抑制AP- 1活性可能是其调控胃癌细胞生长的机制之一 .
The effect of all\| trans retinoic acid(ATRA)is mainly mediated by its receptors,RARs and RXRs.The role of RARβ in growth inhibition by ATRA and the underlying mechanism in human gastric cancer cells were investigated.Expression level of RARβ mRNA was detected by Northern blot.The expression vector containing a RARβ gene was transfected into MKN\|45 cells which did not express RARβ mRNA by CellFECTINtm.Growth inhibition and statue of cells were detected by MTT assay and the method of colony formation of cells in soft agar,respectively.To explore the mechanism of RARβ in mediating effect of ATRA,a CAT reporter containing an βRARE(retinioic acid response element)was transiently transfected into cells and CAT assay was carried out.AP\|1 activity was also detected by CAT assay.RARβ expressed in MGC80\|3,BGC\|823 and SGC\|7901 cell lines,which were sensitive to ATRA,but not in MNK\|45 cells resistant to ATRA.When the RARβ gene was introduced and expressed stably in MKN\|45 cells,the cells restored their ATRA sensitivity,which led to growth inhibition of MKN\|45 cells and the inhibition of colony formation of cells in soft agar by ATRA.A stronger induction of CAT activity in response to ATRA was observed in MGC80\|3,BGC\|823 and SGC\|7901 cells.In contrast,only a slighter induction of CAT activity was seen in MKN\|45 cells.However,ATRA could induce the CAT activity of MKN\|45 cells transfected with RARβ gene,whose trend was similar to those of MGC80\|3,BGC\|823 and SGC\|7901 cells.In addition,ATRA could not inhibit AP\|1 activity in MKN\|45 cells.However,AP\|1 activity of MKN\|45 cells was inhibited obviously after cells were transfected with RARβ gene.These results demonstrate that expression of RARβ can contribute to growth inhibition of gastric cancer cells by ATRA.The induction of βRARE transcriptional activity and the inhibition of AP\|1 activity may present one of mechanisms of ATRA in controlling the proliferation of gastric cancer cells.
出处
《中国生物化学与分子生物学报》
CAS
CSCD
2000年第5期689-693,共5页
Chinese Journal of Biochemistry and Molecular Biology
基金
国家自然科学基金!( 3 9880 0 15 )
国家杰出青年科学基金!( B)类 ( 3 982 5 5 0 2 )资助
关键词
胃癌
细胞生长
抑制作用
RARβ受体
ATRA
Retinoic acid receptor β,Growth inhibition,All\| trans retinoic acid,Gastric cancer cell
