Inhibition of proliferation and induction of apoptosis by tanshinone ⅡA in C6 cells

AIM: This study was designed to investigate the inhibition of tanshinone ⅡA on C6 glioma cell line and its mechanism. METHODS: MTT was used to measure the levels of the proliferation of C6 cultured with tanshinone ⅡA at different concentrations. The effects of tanshinone ⅡA on cell cycle of C6 were observed by FCM. The change of DNA was observed by Sepharose electrophoresis. The expression of proto-oncogenes c-myc was measured by RT-PCR. RESULTS: The proliferation of C6 was obviously inhibited by tanshinone ⅡA in a dose-dependent manner. The outcome of FCM showed that the apoptotic cell rate was 7.7%, when cultured with tanshinone ⅡA at 1.0 mg/L for 3 days. The apoptotic cell rate was 21.6%, when cultured with tanshinone ⅡA at 2.0 mg/L in 3 days. CONCLUSION: Tanshinone ⅡA inhibits the proliferation of C6 cells, induces apoptosis and inhibits the expression of proto-oncogene c-myc.     

Effects of shRNA targeting COL1A1 gene on proliferation and apoptosis of human breast cancer cell line MDA-MB-231

AIM: To investigate the effects of shRNA-mediated collagen type I alpha 1 (COL1A1) gene silencing on the proliferation and apoptosis of human breast cancer cell line MDA-MB-231. METHODS: The specific recombinant vector pSilencer2.1-U6-COL1A1 was transiently transfected into human breast cancer cell line MDA-MB-231 with lipofectamine. RT-PCR and Western blotting were performed to detect the expression levels of COL1A1. MTT assay was employed to evaluate the effect of COL1A1 gene silencing on the cell proliferation. Flow cytometry was used to determine the apoptosis and cell cycle of transfected cells. The morphological characteristics of apoptosis were observed by Hoechst 33258 staining. RESULTS: Compared with mock group and scrambled group, the mRNA and protein levels of COL1A1 were reduced by pshRNA-COL1A1 transfection (P<0.05). The proliferation of MDA-MB-231 cells treated in shRNA-COL1A1 was significantly inhibited in a time-dependent way. The percentages of G₀/G₁ phase cells and early apoptotic rate were significantly higher in pshRNA-COL1A1 group than those in mock and scrambled group (P<0.05). The changes of apoptotic morphology such as cell shrinkage and nuclear condensation were also observed by staining with Hoechst 33258 under fluorescence microscope. CONCLUSION: Transfection of eukaryotic expression vector pshRNA-COL1A1 effectively inhibits the proliferation, induces apoptosis and arrests MDA-MB-231 cells in G0/G1 phase.     

Effects of baicalin on CA46 cell proliferation inhibition and apoptosis induction

AIM: To investigate the effects of baicalin on proliferation inhibition and apoptosis induction in human Burkitt lymphoma cell line CA46 and to explore its underlying mechanisms. METHODS: CA46 cells were exposed to baicalin at different dosages and its proliferation inhibition was detected by MTT assay. The ability of baicalin to induce CA46 cell apoptosis was examined by Annexin V-FITC/PI double staining analysis, TUNEL labeling method and DNA fragmentation. The mRNA expressions of c-myc and bcl-2 were detected by RT-PCR, and the protein expressions of c-Myc, Bcl-2, caspase-3 precursor (procaspase-3) and poly ADP-ribose polymerase (PARP) were detected by Western blotting. RESULTS: Baicalin remarkably inhibited the CA46 cell proliferation, with an IC50 value of 10 μmol/L. Apoptosis was remarkably induced by baicalin in a dose-dependent manner, and its earlier and later stages were detected by annexin V-FITC/PI double staining analysis, TUNEL labeling method and DNA fragmentation, respectively. Furthermore, RT-PCR showed that the mRNA expressions of c-myc and bcl-2 in treated CA46 cells decreased in a time-dependent manner. Western blotting showed that the protein expressions of c-Myc, Bcl-2, procaspase-3 and PARP (116 kD) in baicalin treated CA46 cells were down-regulated in a time-dependent manner, while the expression of PARP(85 kD) was up-regulated. CONCLUSION: Baicalin efficiently induces proliferation inhibition and apoptosis in CA46 cells, which may be related with the down-regulation of c-Myc and Bcl-2 expressions, as well as the up-regulation of caspase-3 activity.     

Effects of shRNA targeting SIAH2 gene on proliferation and apoptosis of human hepatoma cell line HepG2

AIM：To investigate the effects of shRNA-mediated seven in absentia homolog 2 (SIAH2; one of ubiquitin ligases) gene silencing on cell cycle and apoptosis of human hepatoma cell line HepG2. METHODS：The specific recombinant vector pGenesil-SIAH2 was transiently transfected into HepG2 cells with Lipofectamine 2000. RT-PCR and Western blotting were performed to detect the mRNA and protein expression levels of SIAH2. MTS assay was employed to evaluate the cell proliferation. Flow cytometry was used to determine the cell cycle and apoptosis of the transfected cells. RESULTS：Compared with control groups, the mRNA and protein levels of SIAH2 were reduced by pGenesil-SIAH2 transfection in HepG2-SIAH2 group. The proliferation of HepG2-SIAH2 cells was significantly inhibited. The percentage of G1-phase cells and the early apoptotic rate were significantly higher in HepG2-SIAH2 cells. CONCLUSION: Tansfection of pGenesil-SIAH2 effectively inhibits the proliferation of HepG2 cells, arrests the cells in G1 phase and induces apoptosis, indicating an experimental basis of SIAH2-targeting gene therapy for hepatocellular carcinoma.     

CHK1 inhibitor SCH900776 suppresses proliferation and migration of U251 cells

AIM: To investigate the effect of SCH900776, an inhibitor of checkpoint kinase 1 (CHK1), on the proliferation and migration abilities of human glioma U251 cells.METHODS: The cell viability was detected by MTT assay, and cell proliferation was determined by cell colony formation assay. Cell cycle distribution was analyzed by flow cytometry. Wound healing assay was used to determine the cell migration ability. The protein levels were determined by Western blot.RESULTS: SCH900776 inhibited the growth of U251 cells in a dose-dependent manner (P<0.05). SCH900776 treatment substantially induced U251 cell cycle arrest in S and G₂/M phases by decreasing the level of cell division cycle protein 2 (Cdc2) and p-Cdc2. Moreover, SCH900776 inhibited the cell migration. Western blot results indicated that SCH900776 increased the phosphorylation level of p38 MAPK and inhibited the activation of Akt.CONCLUSION: SCH900776 inhibits the proliferation and migration abilities in human U251 cells by promoting the phosphorylation of p38 MAPK and suppressing the activation of Akt.     

Knockdown of astrocyte elevated gene-1 by siRNA inhibits cell proliferation and induces apoptosis in human neuroblastoma cell line

AIM: To investigate the effect of siRNA-induced astrocyte elevated gene-1 ( AEG-1 ) down-regulation on the proliferation, apoptosis and cell cycle of neuroblastoma cells. METHODS: An siRNA targeting to AEG-1 mRNA (AEG-1 siRNA) was constructed and transfected into neuroblastoma cells with Lipofectamine 2000. A non-specific siRNA (control siRNA) and non-treatment were used as negative control and blank control,respectively . The cell proliferation was detected by MTT method and colony formation assay. The apoptosis and cell cycle were analyzed by flow cytometry. RESULTS: Compared with control groups, the expression of AEG-1 mRNA was evidently declined in the cells transfected with AEG-1 siRNAs (P<0.05). AEG-1 siRNA significantly decreased the cell proliferation. After treated with AEG-1 siRNA for 48 h, the percentage of apoptotic cells was significant increased and the cell cycle was arrested in G₀/G₁ phase compared with the control cells (P<0.05). CONCLUSION: The mRNA expression of AEG-1 is down-regulated by AEG-1 siRNA in neuroblastoma cells. Knockdown of AEG-1 expression in human neuroblastoma cells significantly inhibits cell proliferation and apoptosis, and induces cell arrest in G₀/G₁ phase of the cell cycle.     

Effect of ROCK1 and ROCK2 silencing by shRNA on hypoxia-induced apoptosis of rat cardiomyocytes

AIM: To investigate the effects of Rho-associated coiled-coil protein kinase-1 (ROCK1) and ROCK2 on apoptosis induced by hypoxia in rat cardiomyocytes. METHODS: Rat cardiomyocytes were cultured primarily and identified using an antibody targeting α-actin of striated muscle. ROCK1-shRNA and ROCK2-shRNA were transiently transfected into the cells by liposome. After 48 h, these cells were subject to hypoxia for 6 h. The cells were divided into 5 groups: blank control group, hypoxia group, hypoxia+negative control shRNA group, hypoxia+ROCK1-shRNA group and hypoxia+ROCK2-shRNA group. The beating frequency and rhythm of the cardiomyocytes were assessed by microscopy. The activity of lactate dehydrogenase (LDH) in the cell culture supernatants was detected by automatic biochemical analyzer. The cell survival rate was analyzed by the method of MTT. The cell apoptotic rate was assessed by flow cytometry. Western blotting was used to determine the expression of ROCK1, ROCK2, caspase-3 and p-PI3K. RESULTS: The primary culture of the cardiomyocytes was successful. Western blotting results showed that the transfection of ROCK1-shRNA or ROCK2-shRNA decreased the expression of ROCK1 or ROCK2 in the cardiomyocytes. Hypoxia slowed down the beat frequency of the cardiomyocytes, also made the rhythm disorder. Hypoxia increased the release of LDH and decreased the cell survival rate. Flow cytometry results showed that hypoxia increased the cell apoptotic rate. Hypoxia increased the expression of caspase-3 and decreased the expression of p-PI3K. Transfection of ROCK1-shRNA and ROCK2-shRNA into the cardiomyocytes reduced all the effects of hypoxia mentioned above. CONCLUSION: Down-regulation of ROCK1 and ROCK2 expression suppresses the apoptosis of rat cardiomyocytes induced by hypoxia. The mechanism is associated with the inhibition of caspase-3 activation and the up-regulation of p-PI3K expression.     

Effects of adenovirus-mediated shRNA targeting PTEN on proliferation and apoptosis of activated hepatic stellate cells in vitro

AIM:To investigate the down-regulation of phosphatase and tensin homolog deleted on chromosome 10(PTEN) gene by adenovirus-mediated short hairpin RNA(shRNA) on proliferation and apoptosis of activated hepatic stellate cells(HSCs) in vitro and the related signaling transduction pathways. METHODS:The activated HSCs were cultured in vitro and transfected with recombinant adenovirus expressing shRNA targeting PTEN. The proliferation of HSCs was measured by MTT assay and the apoptosis was assessed by TUNEL and flow cytometry. Western blotting was used to detect the protein levels of PTEN, Bax, Bcl-2, Akt, p-Akt, ERK1/2 and p-ERK1/2 in HSCs, and real-time fluorescent quantitative PCR was applied to detect the mRNA expression of Akt and ERK1. RESULTS:The recombinant adenovirus expressing shRNA targeting PTEN was successfully transfected into activated HSCs in vitro, and significantly promoted the proliferation of HSCs in a time-dependent manner within a certain extent. The apoptotic rate of HSCs was significantly decreased 72 h after transfection(P<0.05). Meanwhile, reduced expression of Bax and elevated expression of Bcl-2 were induced 72 h after transfection(P<0.05). Furthermore, the expression of p-Akt and p-ERK1/2 were increased significantly(P<0.05), while no significant difference in the expression of Akt and ERK1 at mRNA and protein levels was observed(P>0.05). CONCLUSION:Down-regulation of PTEN by adenovirus-mediated shRNA dramatically promotes the proliferation of activated HSCs, and inhibits the apoptosis through Bcl-2/Bax pathway. In addition, the phosphorylation of Akt and ERK1/2 is increased, indicating that PI3K/Akt and ERK1/2 signal transduction pathways may play an important role in the regulation of proliferation and apoptosis of HSCs.     

Effect of fucoidan on inhibition of proliferation and induction of apoptosis in human breast carcinoma cell line MCF-7

AIM: To investigate the effects and related mechanism of fucoidan on the proliferation and apoptosis in breast carcinoma cell line MCF-7. METHODS: MCF-7 cells were treated with different concentrations of fucoidan (100 mg/L, 300 mg/L, 500 mg/L, 1 000 mg/L) for 48 h. Cell viability was measured by MTT assay. Apoptosis morphological and biochemical changes were detected by Hoechst 33258 staining and agarose gel electrophoresis. The expression of 〖STBX〗bcl-2〖STBZ〗 and bax was examined by RT-PCR and Western blotting. RESULTS: Fucoidan at different concentrations (100 mg/L, 300 mg/L, 500 mg/L, 1 000 mg/L) effectively inhibited the proliferation of MCF-7 cells (P<0.01). The inhibitory ratio and apoptosis rate increased in a concentration-dependent manner. Agarose gel electrophoresis of DNA revealed the characteristic “ladder” pattern of apoptosis. Fucoidan down-regulated the expression of 〖STBX〗bcl-2〖STBZ〗 and up-regulated bax in the levels of mRNA and protein. The ratio of Bcl-2 to Bax decreased as the concentrations of fucoidan increased (P<0.05). CONCLUSION: Fucoidan inhibits the cell proliferation by inducing cell apoptosis, and the apoptosis is related to the down-regulation of anti-apoptotic protein Bcl-2 and up-regulation of apoptotic protein Bax.     

Effect of annexin A2 on proliferation,migration and apoptosis of human cervical cancer HeLa cells

AIM：To explore the effect of annexin A2 (ANXA2) on the proliferation, migration and apoptosis abilities of human cervical cancer HeLa cells. METHODS：Overexpression vectors and siRNA of ANXA2 were constructed, and then transfected into HeLa cells. The HeLa cells were divided into 4 groups:control group, scramble group, ANXA2 overexpression group and ANXA2-siRNA group. The expression of ANXA2 at mRNA and protein levels was examined by real-time PCR and Western blotting. MTT assay, Boyden chamber and flow cytometry were used to determine the effect of ANXA2 on the proliferation, migration and apoptosis abilities of the HeLa cells. RESULTS：The proliferation and migration of HeLa cells were obviously promoted by ANXA2 overexpression. The proliferation and migration of HeLa cells were remarkably inhibited by the transfection of ANXA2-siRNA. ANXA2 had no effect on apoptosis of HeLa cells. CONCLUSION:Silencing of ANXA2 effectively inhibits the proliferation and migration of cervical cancer cells, but has little effect on apoptosis. ANXA2 may play a pivotal role in the occurrence and development of cervical cancer, and may be used as a molecular target for the treatment of cervical cancer.     

Inhibition of proliferation in B lymphoma cell line Raji transfected with exogenous HCAP1 gene

AIM: HCAP1 gene has been mapped at human chromosome band 17p13.3, a region with high frequency of loss of heterzygosity in various types of tumor. The aim of this study was to investigate the effects of exogenous HCAP1 gene products on proliferation of B lymphoma cell line Raji. METHODS: HCAP1 gene was transfected into Raji cells. The cells stably expressed exogenous HCAP1 gene were screened with G418. The effects of HCAP1 protein overexpression on proliferation in Raji cells were assessed by viable cell count, cell growth curve, colony formation assay in soft agar, and 5-bromo-2'-deoxy-uridine (BrdU) labeling and detection assay. RESULTS: The Raji cells overexpressed HCAP1, displayed significantly slow growth rate, extended cell doubling time, decreased capacity of colony formation and reduced percentage of BrdU incorporation in the cells (P<0.05), as compared with control Raji cells which transfected with empty vector, or compared with parent Raji cells. CONCLUSION: Overexpression of exogenous HCAP1 in Raji cells inhibits the cell proliferation.     

Nucleostemin specific RNAi influences cell proliferation in HeLa cells in vitro and in vivo

AIM: To examine Nucleostemin (NS) expression in tumor cells, and observe the effect of NS specific RNA interference on the cell proliferation in Hela cells. METHODS: Total RNA was extracted from 6 kinds of cultured tumor lines, the NS expression level was measured by RT-PCR and Northern blot. An NS-specific siRNA expression vector was constructed to transfect HeLa cell (NS-siRNA-HeLa), and the proliferation of the cell was observed. RESULTS: NS was highly expressed in 6 kinds of tumor cells. NS expression level in the NS-siRNA-HeLa cells was remarkably reduced, and the percentage of G0/G1 cells increased. The neoplasm forming ability in nude mice by the NS-siRNA-HeLa cells was decreased. CONCLUSION: NS is highly expressed among tumor cells. NS-specific siRNA inhibits the entry of the cell cycle into the S phase, and remarkably reduces the proliferation ability of HeLa cells in vitro and in vivo.     

Inhibition of human hepatocellular carcinoma cell proliferation by galactose receptor mediated c-myc antisense oligonucleotide

AIM: To evaluate the inhibitory effect of galactose (Gal)-polyethyleneimine (PEI)-c-myc antisense oligodeoxynucleotide (ASODN) complex on proliferation of human hepatocellular carcinoma cells. METHODS: Human hepatocellular carcinoma cell line Bel-7402 was treated with Gal-PEI-ASODN complex. Cell proliferation was tested by trypan blue dye at different time points and with various concentrations of ASODN treatment. Cell morphology was observed under inverted microscope, cell hypodiploid percentage was analyzed by flow cytometry and cell ultrastructure was observed through electron microscopy. RESULTS: Compared with ASODN group (20 μmol/L) from 0 h to 96 h, Gal-PEI-ASODN complex (with ASODN 0.75 μmol/L) significantly suppressed Bel-7402 cells proliferation, the ASODN concentration within Gal-PEI-ASODN complex and time course acquired were significantly lower and shorter, respectively. Incubated with pure ASODN at different concentrations for 72 hours, cell proliferation was inhibited and IC₅₀ was 20.9 μmol/L; while mediated with galactose receptor for 48 hours, ASODN significantly inhibited cell proliferation and IC₅₀ was only 0.294 μmol/L, the inhibitory efficacy of ASODN enhanced 70.9 folds. While Bel-7402 cells were incubated with Gal-PEI-ASODN complex for 48 hours, cell hypodiploid percentage was much higher than ASODN groups and cell apoptosis was seen under electron microscopy. CONCLUSIONS: Galactose receptor mediated ASODN delivery may significantly increase proliferation inhibition efficacy on Bel-7402 cells.     

Transition of WT1 isoforms inhibits proliferation and promotes apoptosis of human leukemia cell line HL-60

AIM: To study the potential effects of exogenous Wilms tumor 1 (WT1) isoforms on the proliferation and apoptosis of human leukemia cell line HL-60. METHODS: WT1 (17AA－/KTS－) gene obtained by RT-PCR was cloned into a PCDH1-MCS1-EF1-copGFP plasmid. The recombinant plasmid was confirmed by enzyme digestion and sequencing, and was transfected into HL-60 cells by LipofectamineTM 2000. The stable transformants were selected by G418 screening. WT1(17AA－/KTS－) expression was identified by real-time fluorescence quantitative RT-PCR and Western blotting. The proliferation of the cells was measured by MTT assay. The apoptosis of the cells was determined by morphological observation and flow cytometry analysis. RESULTS: The eukaryotic expression vector PCDH1-MCS1-EF1-copGFP-WT1 (17AA－/KTS－) was successfully constructed. The recombinant cells exhibited high mRNA and protein levels of WT1(17AA－/KTS－). The growth of recombinant cells was slower than that of HL-60 cells transfected with control vector and normal HL-60 cells. After exposed to As2O3 at 2 μmol/L for 48 h, both recombinant cells and control cells exhibited the morphological characteristics of apoptosis, but the former was more typical than the latter. The apoptosis was enhanced in the recombinant cells after the cells were exposed to As2O3 for 24 h. CONCLUSION: Exogenous WT1(17AA-/KTS-) isoform inhibits the proliferation and promotes the apoptosis of leukemic cells.     

Role of NHE-1 in the proliferation and apoptosis of pulmonary artery smooth muscle cell in rats

AIM: To evaluate the role of Na⁺/H⁺ exchanger-1(NHE-1)in the proliferation and apoptosis of pulmonary artery smooth muscle cells in rats. METHODS: Twenty Wistar rats were equally randomized into the control group and 3-week hypoxic group. Intracellular pH (pHi) of the smooth muscle was determined with fluorescence measurement of the pH-sensitive dye BCECF-AM and the expression of NHE-1 mRNA was detected with RT-PCR. The primary culture of pulmonary artery smooth muscle cell in vitro was performed. In situ cell death detection kit (TUNEL) was used to study the effect of specific NHE-1 inhibitor, dimethyl amiloride (DMA), on the apoptosis of muscle cells which had intracellular acidification. RESULTS: pHi value and expression of NHE-1 mRNA of pulmonary artery smooth muscle cell were significantly higher respectively in the hypoxic group than those in the control group (P＜0.01). DMA elevated the apoptotic ratio significantly. The effect was enhanced when DMA concentration was augmented and the time was prolonged. CONCLUSION: With the function of adjusting pHi, NHE-1 may play an important role in the proliferation and apoptosis of pulmonary artery smooth muscle cells.     

Inhibition of cell proliferation and arrest of cell cycle progression by blocking Cl- channels in nasopharyngeal carcinoma cells

AIM: The roles of Cl^-channels in regulatory volume decrease (RVD), cell proliferation and cell cycle progression in nasopharyngeal carcinoma cells (CNE-2Z) were investigated. METHODS: Image analysis of living cells was used to detect the volume changes following exposure to hypotonic solutions. Cell viability was determined by the trypan blue assay. MTT method was applied to detected cell proliferation. The effect of the blocker on the cell cycle distribution was monitored by the flow cytometry. RESULTS: 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) inhibited RVD and cell proliferation in a dose-dependent manner. NPPB at the concentration of 100 μmol/L arrested cells in G₁ phase (G₁ population increased from 54% to 71% at 48 h after treatments), but did not significantly alter cell viability. CONCLUSION: Block of chloride channels suppressed cell proliferation by arresting cells in G₁ phase. The results suggest that activation of Cl^-channels and RVD is necessary for facilitating cells to proceed to the S phase from G₁ phase and maintaining cell proliferation.     

Effect of gambogic acid on proliferation and apoptosis of human diffuse large B-cell lymphoma cell line OCI-LY-1

AIM: To investigate the effects of gambogic acid (GA) on the proliferation and apoptosis of human diffuse large B-cell lymphoma cells. METHODS: Diffuse large B-cell lymphoma cell line OCI-LY-19 was treated with GA. The cell viability and proliferation were evaluated by MTS assay. The morphological changes of the cells were observed under inverted microscope and fluorescence microscope with PI staining. The cell apoptosis was detected by flow cytometry. The changes of proteasome-related proteins Ubs, Bax, HSP90 and IκB-α, the apoptosis-related proteins PARP, pro-caspase-3 and caspase-8, and the proliferation-associated molecules ERK and STAT5 were detected by Western blotting. RESULTS: The proliferation of OCI-LY-19 cells was inhibited and the apoptosis was induced by GA. The expression of Ubs, Bax and HSP90 was up-regulated by GA treatment in a dose-dependent manner. The PARP protein was cleaved. The levels of apoptosis-related proteins pro-caspase-3 and pro-caspase-8, and proliferation-associated molecules p-Akt, p-ERK and p-STAT5 were down-regulated by GA treatment in a dose- and time-dependent manner. CONCLUSION: Gambogic acid down-regulates the activity of proteasome, inhibits cell proliferation and promotes cell apoptosis of diffuse large B cell lymphoma.     

Effects of Smo gene silencing on cell activity and apoptosis of human cervical carcinoma HeLa cells

AIM: To investigate the effect of Hedgehog (Hh) signaling pathway on the viability and apoptosis of cervical carcinoma cells by shRNA technique to knock down Smoothened (Smo) gene. METHODS: Smo shRNA was used to transfect the cervical carcinoma HeLa cells. The expression of Smo and Gli1 at mRNA and protein levels in the HeLa cells was determined by RT-PCR and Western blot, respectively. The effect of Smo gene silencing on the growth of the cells was measured by MTT assay. The apoptosis and cell cycle were determined by flow cytometry. RESULTS: Compared with control group, the mRNA and protein expression of Smo and Gli1 were evenly reduced obviously after transfected with Smo shRNA for 72 h (P<0.05). The viability of HeLa cells transfected with Smo shRNA was significantly inhibited. The percentages of the cells in G₀/G₁ phase and early apoptosis rate were obviously higher in Smo shRNA transfection group than those in control group. CONCLUSION: Smo gene silencing effectively inhibits the cell growth and induces the apoptosis of human cervical carcinoma cells.     

Inhibition of 293T cell proliferation by blocking miR-20 and miR-106 expression with antisense RNA

AIM: To inhibit 293T cell proliferation by reducing miR-20 and miR-106 expression with antisense RNA. METHODS: Antisense RNA (or antisense oligonucleotides, ASO) specific to miR-20 and miR-106 was synthesized, and the 293T cells were treated with these antisense RNA. Then, the cell proliferation derived from suppression of antisense RNA was studied by microscopy and fluorescence-activated cell sorter. The expression of miRNA and its target gene Rb were analyzed by real-time PCR and ELISA, respectively. RESULTS: Our results showed that ASO could inhibit the expression of miR-20 and miR-106 effectively and inhibit 293T cell proliferation. The results also demonstrated that ASO specific to miR-106 could up-regulate anti-oncogene Rb expression. CONCLUSION: ASO could inhibit 293T cell proliferation by inhibiting miRNA expression and up-regulating Rb expression.     

Effects of MAGEA3 inhibition by shRNA on apoptosis in human hepatocellular cancer cells

AIM:To investigate the inhibitory effect of vector-based RNA interference ( RNAi) on the expression of melanoma associated antigen A3 (MAGEA3) protein in hepatocellular carcinoma cells and on apotposis of hepatocellular carcinoma cells. METHODS:A vector for transcribing specific small hairpin RNA ( shRNA) targeting MAGEA3 gene was constructed ,introduced into hepatocellular carcinoma MEL-ED1 cells by Lipofectamine 2000. The MAGEA3 protein and mRNA expression levels of MEL-ED1 cells were detected by Western blotting and RT-PCR, respectively. The cell apoptosis was studied by DNA fragmentation, electron microscopy ，TUNEL assay, and annexin V/PI staining. RESULTS:The vector of RNA interference was successfully constructed and MAGEA3 expression was descreased significantly in MEL-ED1 cells. After the shRNA expression vector was transfected into the MEL-ED1 cells, the expression of MAGEA3 gene was inhibited significantly ( by 90% ). DNA fragmentation，electron microscopy and TUNEL assay showed classic apoptosis characters in the MEL-ED1 cells transfected with pSilencer-MAGEA3 plasmid with an apoptosis rate of 21.41% ±1.98%, significantly higher than those in the negative control group transfected with pSilencer-neo and in the non-transfected group (both P<0.01). CONCLUSION:The specific small hairpin RNA targeting MAGEA3 mRNA can inhibit the expression of MAGEA3 and cause apoptosis of hepatocellular carcinoma cells , which suggests inhibitory effect of MAGEA3 on apoptosis in cancer and provides an experimental basis for treating human tumors with RNAi.