Effect of oridonin on invasion and migration of human lung cancer NCI-H460 cells

AIM：To investigate the effect of oridonin on the invasion and migration of human lung cancer NCI-H460 cells. METHODS：NCI-H460 cells were divided into high-dose (HD), middle-dose (MD) and low-dose (LD) oridonin groups (cultured with 40, 20 and 10 μmol/L of oridonin, respectively, as experimental groups), and normal (N) group (treated without oridonin as control). The cell growth was observed. The cell proliferation was detected by MTT assay. Boyden chamber was used to determine the cell invasive capacity. The cell migration was also measured. The levels of MMP-2 and MMP-9 were assayed by Western blotting. RESULTS：The cell counts in the experimental groups were lower than that in N group. The cell proliferation was inhibited as the inhibitory rates were 48.94%, 36.17% and 19.15% for HD group, MD group and LD group, respectively. The numbers of the invasive cells were 26.67±5.16 for HD group, 36.17±5.08 for MD group, and 44.33±5.50 for LD group. The migration rates in the experimental groups were lower than that in N group. The expression of MMP-2 and MMP-9 decreased dependent on the oridonin dose as follows: HD group < MD group < LD group < N group. CONCLUSION：Oridonin inhibits the invasion and migration of NCI-H460 lung cancer cells, and reduces the expression of MMP-2 and MMP-9.     

RASSF1A expression mediated by lentivirus inhibits growth of small-cell lung cancer cell line H446

AIM：To explore the inhibitory effect of Ras-association domain family 1A (RASSF1A) on the small-cell lung cancer cell growth. METHODS：The lentiviral expression vector containing RASSF1A gene was constructed and used to infect the small-cell lung cell line H446. The growth curve and cell cycle were detected by MTT assay and flow cytometry. The mRNA and protein levels of cell cycle-associated proteins were determined by real-time PCR and Western blotting. RESULTS：We obtained the H446 cells in which RASSF1A was stably expressed (named RASSF1A-H446). Compared with normal cell group and negative cell group, RASSF1A inhibited the proliferation of H446 cells, and arrested H446 cells in G1 phase. The expression of p21 and p27 was significantly increased, and E2F1 was significantly decreased in RASSF1A-H446 cells. CONCLUSION：RASSF1A inhibits the H446 cell growth by increasing the expressions of p21 and p27, and decreasing the expression of E2F1.     

TPX2 induces apoptosis of rectal cancer HR-8348 cells through p38 MAPK signaling pathway

AIM: To study the effect of targeting protein for Xenopus kinesin-like protein 2 (TPX2) expression knockdown on the apoptosis of rectal cancer HR-8348 cells.METHODS: The HR-8348 cells transfected with TPX2 small interfering RNA (siRNA) served as TPX2 siRNA group. The non-transfected cells were used as control group. The cells transfected with siRNA negative control (siRNA-NC) were used as siRNA-NC group. The TPX2 siRNA-transfected cells exposed to p38 MAPK inhibitor SB203580 served as TPX2 siRNA+SB203580 group. The expression of TPX2 at mRNA and protein levels was determined by RT-qPCR and Western blot. The cell viability was measured by MTT assay, the apoptosis was analyzed by flow cytometry. The protein levels of p38 MAPK, p-p38 MAPK, cleaved caspase-3 and Bcl-2 in the HR-8348 cells were determined by Western blot.RESULTS: After transfection, the expression of TPX2 at mRNA and protein levels was decreased in TPX2 siRNA-transfected cells (P<0.05). Transfection with siRNA-NC had no effect on TPX2 mRNA and protein levels in the cells. After knockdown of TPX2 expression, the viability of rectal cancer HR-8348 cells and the expression of Bcl-2 were decreased, while the apoptotic rate and the protein levels of cleaved caspase-3 and p-p38 MAPK/p38 MAPK were increased significantly reduced (P<0.05). Compared with TPX2 siRNA group, the apopto-tic rate and the protein levels of cleaved caspase-3 and p-p38 MAPK/p38 MAPK in TPX2 siRNA+SB203580 group were significantly decreased, while the viability was significantly increased (P<0.05).CONCLUSION: Knockdown of TPX2 expression promotes apoptosis of rectal cancer HR-8348 cells by activating p38 MAPK signaling pathway.     

Effect of BMP9 over-expression on migration and invasion of human lung squamous-cell carcinoma NCI-H520 cells

AIM: To investigate the effect of bone morphogenetic proteins 9(BMP9) on the migration and invasion abilities of human lung squamous-cell carcinoma NCI-H520 cells and its mechanism. METHODS: The expression of BMP9 at mRNA and protein levels in the NCI-H520 cells and human bronchial epithelial (HBE) cells was detected by RT-PCR and Western blot. The NCI-H520 cells were transfected with the recombinant adenovirus AdBMP9 and the expression of BMP9 at mRNA and protein levels was validated by RT-PCR and Western blot. The migration and invasion abilities of the NCI-H520 cells were determined by wound-healing and Transwell assays. The mRNA and protein levels of the migration-related factor matrix metalloproteinase 2(MMP2) were detected by RT-PCR and Western blot. The level of phosphorylated Smad1/5(p-Smad1/5) was detected by Western blot. Meanwhile, NCI-H520 cells were treated with BMP specific antagonist AdNoggin and AdBMP9. The level of p-Smad1/5 and the cell migration ability were measured by Western blot, wound-healing and Transwell assays. RESULTS: The expression of BMP9 at mRNA and protein levels was lower in NCI-H520 cells than that in HBE cells. After AdBMP9 was stably transfected into the NCI-H520 cells, the expression of BMP9 at mRNA and protein levels was significantly up-regulated, cell migration and invasion abilities were significantly decreased, and the mRNA and protein levels of MMP2 were decreased. Meanwhile, the level of p-Smad1/5 was increased. Noggin reversed BMP9-caused the increase in p-Smad1/5 and the decrease in cell migration ability. CONCLUSION: Over-expression of BMP9 inhibits the migration and invasion abilities of lung squamous-cell carcinoma NCI-H520 cells. The activation of BMP-Smad signaling pathway may be involved in this inhibitory process.     

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.     

Effect of serum amyloid A on invasion,migration and MAPK signaling pathway in osteosarcoma cells

AIM: To investigate the effect of silencing of serum amyloid A (SAA) on the viability, apoptosis, migration and mitogen-activated protein kinase (MAPK) signaling pathway in osteosarcoma U2OS cells. METHODS: Small interfering RNA (siRNA) targeting SAA was transfected into U2OS cells to silence the expression of SAA gene. The U2OS cells were divided into blank control group, negative control group, and experimental group. The cells in negative control group and experimental group were transfected into negative control siRNA and SAA-siRNA, respectively. The cells in blank control group were without any treatment. The viability of the cells was measured by MTT assay and the apoptotic rate was analyzed by flow cytometry with Annexin V-FITC/PI double staining. The migration and invasion abilities of the cells were detected by Transwell chamber assay. The protein levels of SAA, phosphorylated p38 MAPK (p-p38 MAPK) and phosphorylated c-Jun N-terminal kinase (p-JNK) in the cells were determined by Western blot. RESULTS: The protein expression of SAA in SAA-siRNA group was significantly lower than that in blank control group (P<0.05). Compared with blank control group, the cell viability in SAA-siRNA group was significantly decreased (P<0.05), the apoptotic rate was significantly increased (P<0.05), and the invasion and migration abilities were significantly decreased (P<0.05). The protein levels of p-p38 MAPK and p-JNK in SAA-siRNA group were significantly lower than those in blank control group (P<0.05), and no significant difference of total JNK and p38 protein levels was observed. CONCLUSION: Silencing of SAA expression inhibits the viability of osteosarcoma cells, induces apoptosis and decreases the migration of osteosarcoma cells, which may be related to the activation of MAPK signaling pathway.     

Effect of PAK4-LIMK1-cofilin signaling on non-small-cell lung cancer migration and invasion

AIM: To explore the mechanism of p21-activated kinase 4 (PAK4) on non-small-cell lung cancer (NSCLC) migration and invasion.METHODS: After A549 and NCI-H520 cell lines were transfected with PAK4-siRNA or negative control, the expression of PAK4 at mRNA and protein levels was detected by real-time PCR and Western blot, respectively. The invasion and migration of A549 cells and NCI-H520 cells were measured by Matrigel invasion assay and Transwell migration assay. LIMK1, cofilin, and their respective phosphorylation were examined by Western blot. The interaction of PAK4 and LIMK1 was investigated by co-immunoprecipitation assay. The relationship between PAK4 and LIMK1 phosphorylation was examined by a protein kinase assay in the A549 cells and NCI-H520 cells. The expression of PAK4 and p-LIMK1 in 10 human NSCLC tissues was examined by Western blot. A549 cells and NCI-H520 cells were individually or commonly transfected with PAK4-siRNA or LIMK1 plasmid in order to observe the cell migration and invasion. RESULTS: After A549 cells and NCI-H520 cells were transfected with PAK4-siRNA for 48 h, the expression of PAK4 at mRNA and protein levels, and the numbers of invasion and migration cells in PAK4-siRNA group were lower than those in control group. Compared with control group, the phosphorylation of LIMK1 and cofilin was lower in PAK4-siRNA group, whereas the total expression levels of LIMK1 and cofilin did not change. The results of co-immunoprecipitation assays showed that PAK4 specifically interacted with LIMK1 in A549 and NCI-H520 cells. LIMK1 phosphorylation in the presence of PAK4 (K350M) was significantly lower than that in the presence of PAK4 (WT) or PAK4 (S445N) in the protein kinase assay. The PAK4 upregulation was positively correlated with the level of p-LIMK1 (P<0.05). After A549 cells and NCI-H520 cells were co-transfected with PAK4-siRNA and LIMK1 plasmid, the migration and invasion cell numbers in co-transfection group were higher than those in PAK4-siRNA transfection group. CONCLUSION: PAK4 promotes the invasive and migratory abilities of NSCLC, which is mediated by LIMK1 phosphorylation.     

Effect of ABCE 1 gene silencing on proliferation and migration of human bladder cancer cell line T24

AIM: To investigate the effect of small interfering RNA (siRNA)-mediated ABCE1 knockdown on the survival, cell cycle and invasion of human bladder cancer cell line T24. METHODS: The siRNA against ABCE1 was constructed and transfected into the T24 cells with Lipofectamine^TM 2000. The expression of ABCE1 was detected by RT-PCR and Western blot. Flow cytometry was used to detect the cell cycle. The effects of ABCE1 gene silencing on proliferation, migration and invasion of T24 cells were evaluated by CCK-8 assay, wound-healing assay and Transwell invasion assay, respectively. RESULTS: Compared with control group and blank group, the mRNA and protein levels of ABCE1 were significantly decreased in experimental group after transfected with ABCE1 siRNA. The cell cycle was arrested at G₀/G₁ phase and the cell number in S phase was decreased in the T24 cells. Compared with control group and blank group, the proliferation of T24 cells in experimental group was inhibited significantly, and the migration and invasion abilities of T24 cells in experimental group decreased significantly. CONCLUSION: Knockdown of ABCE1 gene may decrease migration, invasion and proliferation abilities in T24 cells.     

Effects of AGR2 on proliferation and apoptosis of NCI-H460 cells induced by thapsigargin

AIM:To observe the effects of anterior gradient 2 (AGR2) gene on the proliferation and apoptosis of NCI-H460 cells induced by thapsigargin, an endoplasmic reticulum (ER) stress inducer.METHODS:A stable cell line with knockdown of endogenously expressed AGR2 mediated by lentiviral shRNA was established. The proliferation abi-lity of stable NCI-H460 cells in the presence of thapsigargin was measured by colony formation assay, while the effect of AGR2 gene silencing on apoptosis in the presence of thapsigargin was analyzed by flow cytometry. RESULTS:Lentivirus-mediated AGR2 knockdown stable NCI-H460 cells was successfully constructed and the expression of AGR2 was markedly diminished as revealed by Western blot (P<0.01). Knockdown of AGR2 didn't significantly affect the colony formation rate and apoptosis of NCI-H460 cells without thapsigargin treatment. Colony formation rate of the cells with AGR2 gene knockdown was far lower than that of the control cells after 24 h of thapsigargin treatment (P<0.05). The results of flow cytometry showed that knockdown of AGR2 significantly increased the apoptosis of NCI-H460 cells induced by thapsigargin. CONCLUSION:Knockdown of AGR2 doesn't remarkably affect the proliferation and apoptosis of NCI-H460 cells in the absence of thapsigargin, but significantly decreases cell viability and increases apoptosis after thapsigargin treatment. This study reveals that AGR2 might promote the proliferation and reduce the apoptosis of lung cancer cells under ER stress, and lays the foundation for further study of the AGR2 role in initiation, development and drug resistance of lung cancer.     

Effect of silencing hHBrk1 on proliferation and migration of lung carcinoma cells

AIM: To observe the effect of hHBrk1 gene on proliferation and migration of lung carcinoma cells. METHODS: Recombinant plasmids harboring 19-nt-long small interfering RNA (siRNA) were constructed and tested to selectively downregulate hHBrk1 gene in human lung cancer 95D cell line in vitro by stable transfection with Lipofectamine 2000. The mRNA level of the cells transfected with siRNA plasmids were monitored by Northern blotting and RT-PCR. Growth curve and flow cytometry were applied to determine the cell proliferation and cell cycle. Ability of cell migration was measured by Trans-well system. RESULTS: hHBrk1 gene was silenced by targeting siRNA, and stable silencing cell model was constructed. No difference in proliferation and clone formation between hHBrk1 silencing cells and control cells was observed. The ability of migration was decreased in hHBrk1 silencing cells as compared with control cells. CONCLUSION: hHBrk1 may play an important role in migration of the lung cancer cells.     

Effect of HMGB2 on cell cycle and proliferation of lung adenocarcinoma

AIM: To investigate the effect of high-mobility group protein B2 (HMGB2) on cell cycle and proliferation of lung adenocarcinoma cells. METHODS: Cancer RNA-Seq Nexus (CRN) was used to analyze HMGB2 expression in lung adenocarcinoma tissues. OncoLnc was used to analyze the correlation between HMGB2 and prognosis of lung adenocarcinoma patients. Cancer Single-cell State Atlas (CancerSEA) was used to analyze the correlation between HMGB2 and 14 kinds of functional states of lung adenocarcinoma. siRNA was used to inhibit HMGB2 expression in human lung adenocarcinoma A549 cells. The silencing effects were verified by real-time PCR and Western blot, and the cell proliferation was detected by CCK8 and EdU assays. RESULTS: HMGB2 was over-expressed in the lung adenocarcinoma tissues. The overall survival of the patients with lung adenocarcinoma in HMGB2 high expression group was significantly lower than that of the patients with low expression of HMGB2 (log-rank test P=0.017 3). HMGB2 expression was positively correlated with cell cycle and proliferation of lung adenocarcinoma cells. The viability and proliferation ability of A549 cells after HMGB2 expression knock-down were significantly reduced (P < 0.05). CONCLUSION: The expression of HMGB2 is positively correlated with the cell cycle and proliferation of lung adenocarcinoma, and it can be used as a potential marker for evaluating the prognosis and therapeutic target of patients with lung adenocarcinoma.     

PGRN gene silencing on proliferation and migration abilities of human non-small-cell lung cancer A549 cells

AIM: To investigate the effect of small interfering RNA (siRNA)-mediated progranulin (PGRN) gene silencing on the proliferation and migration abilities of human non-small-cell lung cancer A549 cells and its mechanism. METHODS: The mRNA and protein expression levels of PGRN in the A549 cells and human bronchial epithelial (HBE) cells were detected by qPCR and Western blot. A549 cells were transfected with PGRN-siRNA by liposome method. The expression of PGRN at mRNA and protein levels in the A549 cells transfected with PGRN-siRNA was detected by qPCR and Western blot, respectively. The cell viability was measured by MTT assay. The cell proliferation ability was measured by living cells counting and crystal violet staining assays. The cell migration ability was measured by wound-healing and Transwell assays. The protein levels of proliferating cell nuclear antigen (PCNA), cyclin D1, Bcl-2 and Bax were determined by Western blot. The protein levels of phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and phosphorylated protein kinase B (p-Akt) were also determined by Western blot. RESULTS: The expression of PGRN at mRNA and protein levels was higher in the A549 cells than that in the HBE cells (P<0.05). The expression of PGRN at mRNA and protein levels in the A549 cells transfected with PGRN-siRNA was significantly decreased, and the cell proliferation and migration abilities were significantly decreased. The protein expression levels of PCNA, cyclin D1 and Bcl-2 were significantly reduced and the protein expression level of Bax was significantly increased (P<0.05). Meanwhile, the protein levels of p-ERK1/2 and p-Akt were down-regulated (P<0.05). CONCLUSION: PGRN gene silencing obviously inhibits the proliferation and migration abilities of human non-small-cell lung cancer A549 cells. The PI3K/Akt and MAPK/ERK signaling pathways may play an important role in these processes.     

Effect of small interfering RNA on expression of β2M in pre-differentiated bone marrow mesenchymal stem cells

AIM：To study the effect of small interfering RNA (siRNA) on the expression of beta 2-microglo-bulin (β2M) in pre-differentiated bone marrow mesenchymal stem cells (BMSCs). METHODS：The β2M siRNA was transfected into the pre-differentiated BMSCs with Lipofectamine 2000. BMSCs were divided into transfection group, blank control group and negative control group. The expression of β2M at mRNA and protein levels was determined by real-time qPCR, Western blotting and laser confocal microscopy. The productions of aggrecan and type II collagen in pre-differentiated BMSCs were determined by toluidine blue staining and type Ⅱ collagen immunofluorescence. RESULTS：The results of real-time qPCR, Western blotting and laser confocal microscopy showed that siRNA successfully inhibited the expression of β2M at mRNA and protein levels in the pre-differentiated BMSCs. The results of toluidine blue and type Ⅱ collagen immunofluorescence staining showed that siRNA does not affect the productions of aggrecan and type Ⅱ collagen in the pre-differentiated BMSCs. CONCLUSION：siRNA targeting β2M reduces the expression of β2M in the pre-differentiated BMSCs and does not affect the chondrocyte characteristics of pre-differentiated BMSCs.     

Expression of Gab2 in human osteosarcoma U2-OS cells

AIM: To investigate the expression of Grb2-associated binding protein 2 (Gab2) in human osteosarcoma cells and its relationship with the invasion and metastases of human osteosarcoma cells. METHODS: The technique of small RNA interference was used to transfect human osteosarcoma U2-OS cell lines. Western blotting and RT-PCR were used to detect the protein and mRNA expression of Gab2 in transfected U2-OS cells. After transfection, through chemotaxis and invasion assays in vitro, the cell migration and invasion abilities were detected. RESULTS: After transfection, the expression of Gab2 at mRNA and protein levels in Gab2 siRNA transfected cells (SiGab2/U2-OS) was lower than that in scrambled siRNA transfected cells (Scr/U2-OS) and U2-OS cells. After stimulation with epidermal growth factor (EGF) at concentration of 10 μg/L, the migration SiGab2/U2-OS cells was significantly less than Scr/U2-OS cells and U2-OS cells (P<0.01). The number of invasion cells of SiGab2/U2-OS group was significantly lower than the other 2 control groups (P<0.01). CONCLUSION: Inhibition of Gab2 expression obviously attenuates the migration and invasion abilities of human osteosarcoma U2-OS cell line.     

Inhibitory effects of septin 2 gene silencing induced by siRNA on migration of human colorectal cancer cell line LoVo

AIM:To investigate the expression of septin 2 in human colorectal cancer cell lines and the effect of septin 2 on the capacity of migration of human colorectal cancer cell line LoVo. METHODS:Real-time fluorescence quantitative RT-PCR and Western blotting analysis were used to determine the mRNA and protein levels of septin 2 in different metastatic potential cell lines, respectively. The expression of septin 2 in LoVo cells was silenced by siRNA. The efficacy of siRNA was confirmed by real-time fluorescence quantitative RT-PCR. Septin 2 and its co-localization with F-actin were measured by immunofluorescence method. The migration of transfected cells was analyzed by scratch test. RESULTS:The expression of septin 2 in LoVo cells was significantly higher than that in low metastatic potential cell lines such as SW480, HCT-116 and HT-29 at both mRNA and protein levels. The mRNA expression of septin 2was successfully silenced in LoVo cells by siRNA. Cell wound closure rate was also decreased in septin 2 siRNA group as compared with control group(both P<0.05). The co-expression of septin 2 and F-actin formed the typical filamentous-granular organization, and down-regulation of septin 2 resulted in cell skeleton disturbance with less or shorter pseudopodium and decreased stress fibers. CONCLUSION:Septin 2 is highly expressed in LoVo cells. Partial deletion of septin 2 represses the capability of tumor cell migration.     

Effects of CENP-W down-regulation on human glioma U87 cells

AIM: To study the effect of centromere protein W (CENP-W) down-regulation on human glioma U87 cells.METHODS: Small interfering RNA (siRNA) was used to inhibit the expression of CENP-W in the U87 cells. The interference effect of siRNA was evaluated by RT-qPCR and Western blot. The proliferation of the cells was analyzed by MTT assay, BrdU staining and colony formation experiment. Transwell chamber assay was used to detect the invasion ability of the cells. The cell migration ability was measured by a scratch test. The changes of the cell cycle distribution and apoptosis were analyzed by flow cytometry.RESULTS: The results of MTT assay, colony formation experiment and BrdU staining showed that the cell proliferation and colony formation abilities in experimental group were significantly lower than those in control group and negative control group. The results of Transwell and scratch experiments showed that the migration and invasion abilities in experimental group were weaker than those in blank control group and negative control group. The results of flow cytometry analysis showed that the cell cycle distribution in experimental group was arrested in G₀/G₁ phase. The percentage of apoptotic cells in experimental group was higher than that in control group (P<0.05).CONCLUSION: Down-regulation of CENP-W expression inhibits the proliferation, migration and invasion of human glioma cells and promotes the apoptosis of the cells, suggesting that CENP-W may be a potential target of gene therapy for human glioma.     

Expression and function of circular RNA_0000231 in non-small-cell lung cancer

AIM: To investigate the expression and function of circular RNA_0000231 (circ_0000231) in non-small-cell lung cancer (NSCLC). METHODS: RT-qPCR was used to detect the expression of circ_0000231 in the NSCLC tissues and cell lines. circ_0000231 small interfering RNA (si-circ_0000231) or negative control siRNA of circ_0000231 (NC) was transfected into the NSCLC cells. The proliferation and apoptosis of the NSCLC cells were detected by CCK-8 assay, colony formation assay and flow cytometry, respectively. The expression of cyclin D1 (CCND1) and anti-apoptotic protein Bcl-2 were determined by RT-qPCR and Western blot. RESULTS: The expression of circ_0000231 in the NSCLC tissues and cell lines was significantly up-regulated compared with precancerous tissues and lung epithelial cells BEAS-2B (P<0.05). After transfection of NSCLC cells with si-circ_0000231, the cell viability, colony formation numbers were significantly decreased, and the apoptotic rate in si-circ_0000231 group was significantly increased as compared with NC group (P<0.01). In addition, the results of RT-qPCR and Western blot showed that transfection of si-circ_0000231 inhibited the expression of CCND1 and Bcl-2 (P<0.01). CONCLUSION: The expression of circ_0000231 is significantly increased in the NSCLC tissues and cells. Knock-down of circ_0000231 expression significantly inhibits the proliferation of NSCLC cells.     

Effects of HIF-1α silencing on proliferation of rat hepatoma cells

AIM：To study the effect of hypoxia-inducible factor 1α (HIF-1α) silencing on the proliferation of hepatoma cells under hypoxia. METHODS：Rat hepatoma cell line CBRH-7919 was used in this study. Hypoxia model was established by treating the cells with cobalt chloride (CoCl2). The expression of HIF-1α was silenced by small interfe-rence RNA. Real-time RT-PCR and Western blotting were used to detect the mRNA and/or protein expression of HIF-1α, vascular endothelial growth factor (VEGF), p21 and cyclin D1 in CBRH-7919 cells under hypoxia. The proliferation of CBRH-7919 cells was measured by the technique of 5-bromo-2’-deoxyuridine (BrdU) incorporation. RESULTS：The expression of HIF-1α and VEGF at mRNA and protein levels was significantly increased under hypoxia (P<0.05). Silencing of HIF-1α significantly inhibited the expression of HIF-1α, VEGF and cyclin D1 at mRNA and/or protein levels, while increased the protein expression of p21 (P<0.05). The BrdU-positive cells in HIF-1α siRNA transfection group were significantly less than those in control group. CONCLUSION：HIF-1α silencing significantly inhibits the proliferation of hepatoma cells under hypoxia.