Orthopedic manifestations in children with Prader-Willi syndrome.

BACKGROUND: Prader-Willi syndrome (PWS) is a rare genetic disease often associated with bone problems, mainly scoliosis and hip dysplasia (HD). This study aimed to analyze the clinical characteristics of orthopedic deformities in patients with PWS. METHODS: A retrospective study was conducted on 175 patients up to March 2023. The Cobb angle(CA) of the spine, the alpha angle of the hip joint, and the acetabular index (AI) were measured. This study aimed to evaluate the relationship between demographic parameters and bone deformities. RESULTS: Scoliosis was found in 66 patients (43.7%), including 52 (78.8%) with mild scoliosis, 10 (15.2%) with moderate scoliosis, and 4 (6.1%) with severe scoliosis. Only seven patients received orthopedic treatment (10.6%). The median age of scoliosis was 4.5 years old, and the prevalence of scoliosis increased rapidly at the age of 5 years and adolescence. The mean CA in this study increased gradually with age. HD was found in 47 patients (38.2%), and 6 patients received orthopedic treatment (12.7%). The median age at HD was 1.8 years old. The mean AI of the study population decreased with age. The prevalence of HD treated with recombinant human growth hormone (rhGH) was low. No significant differences were observed in sex, genotype, body mass index (BMI), obesity rate, or onset of scoliosis and HD. CONCLUSION: The prevalence of scoliosis and HD was higher in patients with PWS. The onset age and developmental trends of the different skeletal malformations were different. Early diagnosis and treatment are important for the prognosis and treatment of orthopedic diseases in patients with PWS.

Effect of harvest dates on ß-carotene content and forage quality of rye (Secale cereale L.) silage and hay.

Limited data about the effects of various factors on forage quality and ß-carotene content of rye produced in Korea are available, so this study investigated the effects of two preservation methods. Samples were collected from rye harvested every 5 days between April 25 and May 31, and comparisons were done among rye silage wilted for different periods of time and hay of three growth stages of rye. For the silage, dry matter (DM), acid detergent fiber (ADF), and neutral detergent fiber (NDF) contents increased with advanced maturity of rye, whereas crude protein, in vitro dry matter digestibility (IVDMD), total digestible nutrients (TDN), relative feed value (RFV), and DM loss decreased (p < 0.0001). Wilting increased the DM content and pH value significantly (p < 0.0001). Silage harvested at the heading stage had the lowest pH value (4.45), propionic acid (0.83 g/kg DM), butyric acid (0 g/kg DM), and fungi and yeast populations (3.70 Log CFU/g of fresh matter [FM]); conversely, it had the highest lactic acid (9.7 g/kg DM), lactic acid bacteria (LAB) (6.87 Log CFU/g of FM), total microorganisms (TM) (7.33 Log CFU/g of FM), and Flieg's score (70) (p < 0.0001). Wilting elevated LAB and TM populations, but it had no consistent effect on other fermentation products. Both delayed harvest and prolonged wilting decreased ß-carotene content. Rye silage harvested around May 9 (heading stage) with 24 h of wilting was preferred for highland, Pyeongchang. For rye hay, advanced maturity decreased DM loss, IVDMD, TDN, and RFV, but it increased DM, ADF, and NDF significantly (p < 0.05). ß-carotene was decreased by delay of hay-making. Consequently, to attain lower DM loss and higher hay quality, the harvest date of May 9 (heading stage) is recommended.

Changes in fermentation pattern and quality of Italian ryegrass (Lolium multiflorum Lam.) silage by wilting and inoculant treatments.

OBJECTIVE: This study was conducted to investigate the effects of wilting and microbial inoculant treatment on the fermentation pattern and quality of Italian ryegrass silage. METHODS: Italian ryegrass was harvested at heading stage and ensiled into vinyl bags (20 cm×30 cm) for 60d. Italian ryegrass was ensiled with 4 treatments (NWNA, no-wilting noadditive; NWA, no-wilting with additive; WNA, wilting no-additive; WA, wilting with additive) in 3 replications, wilting time was 5 hours and additives were treated with 106 cfu/g of Lactobacillus plantarum. The silages samples were collected at 1, 2, 3, 5, 10, 20, 30, 45, and 60 days after ensiling and analyzed for the ensiling quality and characteristics of fermentation patterns. RESULTS: Wilting treatment resulted in lower crude protein and in vitro dry matter digestibility and there were no significant differences in acid detergent fiber (ADF), total digestible nutrient (TDN), water-soluble carbohydrate (WSC), ammonia content, and pH (p>0.05). However, wilting treatment resulted in higher ADF and neutral detergent fiber content of Italian ryegrass silage (p<0.05), and the WNA treatment showed the lowest TDN and in vitro dry matter digestibility. The pH of the silage was higher in the wilting group (WNA and WA) and lower in the additive treatment group. Meanwhile, the decrease in pH occurred sharply between the 3-5th day of storage. The ammonia nitrogen content was significantly lower in the additive treatment (p<0.05), and wilting had no effect. As fermentation progressed, the lactic and acetic acid contents were increased and showed the highest content at 30 days of storage. CONCLUSION: The wilting treatment did not significantly improve the silage fermentation, but the inoculant treatment improved the fermentation patterns and quality of the silage. So, inoculation before ensiling is recommended when preparing high quality of Italian ryegrass silage, and when wilting, it is recommended to combine inoculation for making high quality silage.

Neurofibromin Is an Estrogen Receptor-α Transcriptional Co-repressor in Breast Cancer.

We report that neurofibromin, a tumor suppressor and Ras-GAP (GTPase-activating protein), is also an estrogen receptor-α (ER) transcriptional co-repressor through leucine/isoleucine-rich motifs that are functionally independent of GAP activity. GAP activity, in turn, does not affect ER binding. Consequently, neurofibromin depletion causes estradiol hypersensitivity and tamoxifen agonism, explaining the poor prognosis associated with neurofibromin loss in endocrine therapy-treated ER+ breast cancer. Neurofibromin-deficient ER+ breast cancer cells initially retain sensitivity to selective ER degraders (SERDs). However, Ras activation does play a role in acquired SERD resistance, which can be reversed upon MEK inhibitor addition, and SERD/MEK inhibitor combinations induce tumor regression. Thus, neurofibromin is a dual repressor for both Ras and ER signaling, and co-targeting may treat neurofibromin-deficient ER+ breast tumors.

Retraction Note to: Effect of miR-451 on the Biological Behavior of the Esophageal Carcinoma Cell Line EC9706.

The Editor-in-Chief has retracted this article [1] because Figure 8 overlaps with Figure 6b of [2] and Figure 6 overlaps with Figure 3 of [3] and Figure 3 of [4].

Retraction Note: HAX-1 Promotes the Chemoresistance, Invasion, and Tumorigenicity of Esophageal Squamous Carcinoma Cells.

The Editor-in-Chief has retracted this article [1] because Figure 3c appears to have been modified and reused as Figure 3d.

Concomitant modulation of PTEN and Livin in gastric cancer treatment.

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and Livin are important in the development of gastric cancer (GC). PTEN and Livin are involved in the regulation of tumor cell proliferation, migration and apoptosis. The modulation of PTEN or Livin has been investigated extensively in various cancer models. However, no studies have been performed to evaluate the combined effect of concurrently modulating these two genes on the development of GC. In the present study, the BGC823 human gastric carcinoma cell line was transfected with a dual gene modified vector (pCL-neo-PTEN-siLivin) in parallel with single gene modified vectors (pCL­neo­PTEN or pRNAT­U6.1­siLivin), and an empty control vector. Dual gene modulation (pCL­neo­PTEN­siLivin) had a more marked effect on the inhibition of cell proliferation, induction of apoptosis, and reduction of cell penetration in Matrigel, compared with either single gene alone or empty vector transfection. In a xenograft nude mouse model, the inoculation of pCL­neo­PTEN­siLivin­transfected BGC823 cells led to a markedly reduced tumor burden, compared with that in all other inoculation groups. In conclusion, the overexpression of PTEN concomitant with Livin gene silencing was confirmed as a feasible and effective in vitro and in vivo gene modulation method, which may represent a potential therapeutic strategy for the treatment of GC.

[Retracted] Effects of cyclin E gene silencing on the proliferation of esophageal cancer cell lines, EC9706, Eca109 and KYSE30.

Subsequently to the publication of this article, an interested reader drew to our attention the fact that the six panels shown in Fig. 6 shared several areas of identity among them. Following an internal investigation, a laboratory technician, who was responsible for editing the pictures, admitted that the data as presented in the figure had been manipulated after having mislaid some of the original data. The corresponding author of the article takes responsibility for this oversight, and therefore the paper is to be retracted from publication. All of the named authors agree to this retraction. We deeply regret that these errors were allowed to remain in the paper, and extend our apologies to the readership of the Journal. [the original article was published in Molecular Medicine Reports 7: 799-804, 2013; DOI: 10.3892/mmr.2013.1280].

Regulatory T cell activity in immunosuppresive mice model of pseudomonas aeruginosa pneumonia.

Pseudomonas aeruginosa (PA) pneumonia is a refractory, even lethal complication in immunosuppressive individuals and immune disturbances may promote the pathological process. We aimed to investigate the regulatory T (Treg) cell activity in an immunosuppressive mice model of PA pneumonia by estimating levels of main transcription factor and the main effector of Treg cells, i.e., Forkhead box protein 3 (FOXP3) and interleukine-10 (IL-10). Seventy-two BALB/c mice were divided into four groups randomly: control (A), PA pneumonia (B), immunosuppression (C) and immunosuppression with PA pneumonia (D). Mice were sacrificed at 4, 8 and 24 h after establishing experimental models. The pathological changes of lung tissue were graded, and the FOXP3 mRNA and serum IL-10 levels were detected. Histological analysis of lung tissues showed there were no significantly pathological changes in groups A and C, but significantly pathological changes were found in groups B and D, especially in group D at 8 h (P<0.05). The expression levels of FOXP3 mRNA in groups A and C showed no significant changes at the three time points, which were significantly lower than those in groups B and D (P<0.05). FOXP3 mRNA levels were lowest at 4 h, and there was significant difference between groups B and D (P<0.05). The serum levels of IL-10 in groups A and C were almost normal at the three time points, but decreased significantly in groups B and D (P<0.05). The serum levels of IL-10 decreased to the lowest at 8 h, especially in group D (P<0.05). The results indicate that PA pneumonia in immunosuppressive individuals worsens rapidly, which may be associated with Treg cells function disturbance. And Treg cells may be promising as adjuvant therapeutics for PA pneumonia in immunosuppressive individuals.

Inhibitory effect of α-solanine on esophageal carcinoma in vitro.

α-solanine, a bioactive component and one of the major steroidal glycoalkaloids in potatoes, has been observed to inhibit growth and induce apoptosis in cancer cells. However, the antitumor efficacy of α-solanine on esophageal carcinoma has yet to be fully elucidated. In the present study, the antitumor efficacy of α-solanine against human esophageal carcinoma cells was investigated. It was determined that α-solanine inhibited the growth and proliferation of human esophageal EC9706 and Eca109 cancer cells in a dose-dependent manner, as well as the cell migration and invasion. In addition, the apoptotic rate was increased in the cancer cells treated with α-solanine in a dose-dependent manner, compared with that of the control group (P<0.05). The expression levels of tumor metastasis-related proteins, including matrix metalloproteinase (MMP)-2 and MMP-9, were reduced in the cells treated with α-solanine, as compared with the control group. Conversely, significantly higher expression levels of E-cadherin were detected in the α-solanine-treated groups, as compared with the control group (P<0.05). Therefore, the current results provide a novel insight into the anti-tumor mechanism of α-solanine, and suggest that α-solanine is a potential agent for the prevention and treatment of esophageal carcinoma.

Enteral nutrition versus parenteral nutrition after major abdominal surgery in patients with gastrointestinal cancer: a systematic review and meta-analysis.

To clarify the benefits of enteral nutrition (EN) versus total parenteral nutrition (TPN) in patients with gastrointestinal cancer who underwent major abdominal surgery. Medline, Cochrane, EMBASE, and Google Scholar were searched for studies published until July 10, 2015, reporting outcomes between the two types of postoperative nutritional support. Only randomized controlled trials (RCTs) were included. A χ(2)-based test of homogeneity was performed using Cochran's Q statistic and I(2) A total of 2540 patients (1268 who received EN and 1272 who received TPN; average age range: 58.3-67.7 years) from 18 RCTs were included for assessment. Patients who received EN had shorter lengths of hospital stay (pooled difference in mean=-1.74, 95% CI -2.41 to -1.07, p<0.001, shorter time to flatus (pooled difference in mean=-1.27, 95% CI -1.69 to -0.85, p<0.001), and significantly greater increases in albumin levels (pooled difference in mean=-1.33, 95% CI -2.18 to -0.47, p=0.002) compared with those who received TPN after major abdominal surgery, based on a random-effects model of analysis. EN after major abdominal surgery provided better outcomes compared with TPN in patients with gastrointestinal cancer.

Repair of peripheral nerve defects with chemically extracted acellular nerve allografts loaded with neurotrophic factors-transfected bone marrow mesenchymal stem cells.

Chemically extracted acellular nerve allografts loaded with brain-derived neurotrophic factor-transfected or ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells have been shown to repair sciatic nerve injury better than chemically extracted acellular nerve allografts alone, or chemically extracted acellular nerve allografts loaded with bone marrow mesenchymal stem cells. We hypothesized that these allografts compounded with both brain-derived neurotrophic factor- and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells may demonstrate even better effects in the repair of peripheral nerve injury. We cultured bone marrow mesenchymal stem cells expressing brain-derived neurotrophic factor and/or ciliary neurotrophic factor and used them to treat sciatic nerve injury in rats. We observed an increase in sciatic functional index, triceps wet weight recovery rate, myelin thickness, number of myelinated nerve fibers, amplitude of motor-evoked potentials and nerve conduction velocity, and a shortened latency of motor-evoked potentials when allografts loaded with both neurotrophic factors were used, compared with allografts loaded with just one factor. Thus, the combination of both brain-derived neurotrophic factor and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells can greatly improve nerve injury.

MiR-451 inhibits proliferation of esophageal carcinoma cell line EC9706 by targeting CDKN2D and MAP3K1.

AIM: To investigate the underlying molecular mechanisms of miR-451 to inhibit proliferation of esophageal carcinoma cell line EC9706. METHODS: Assays for cell growth, apoptosis and invasion were used to evaluate the effects of miR-451 expression on EC cells. Luciferase reporter and Western blot assays were used to test whether cyclin-dependent kinase inhibitor 2D (CDKN2D) and MAP3K1 act as major targets of miR-451. RESULTS: The results showed that CDKN2D and MAP3K1 are direct targets of miR-451. CDKN2D and MAP3K1 overexpression reversed the effect of miR-451. MiR-451 inhibited the proliferation of EC9706 by targeting CDKN2D and MAP3K1. CONCLUSION: These findings suggest that miR-451 might be a novel prognostic biomarker and a potential target for the treatment of esophageal squamous cell carcinoma in the future.

Genome organisation of the Acinetobacter lytic phage ZZ1 and comparison with other T4-like Acinetobacter phages.

BACKGROUND: Phage ZZ1, which efficiently infects pathogenic Acinetobacter baumannii strains, is the fifth completely sequenced T4-like Acinetobacter phage to date. To gain a better understanding of the genetic characteristics of ZZ1, bioinformatics and comparative genomic analyses of the T4 phages were performed. RESULTS: The 166,687-bp double-stranded DNA genome of ZZ1 has the lowest GC content (34.4%) of the sequenced T4-like Acinetobacter phages. A total of 256 protein-coding genes and 8 tRNA genes were predicted. Forty-three percent of the predicted ZZ1 proteins share up to 73% amino acid identity with T4 proteins, and the homologous genes generally retained the same order and transcriptional direction. Beyond the conserved structural and DNA replication modules, T4 and ZZ1 have diverged substantially by the acquisition and deletion of large blocks of unrelated genes, especially in the first halves of their genomes. In addition, ZZ1 and the four other T4-like Acinetobacter phage genomes (Acj9, Acj61, 133, and Ac42) share a well-organised and highly conserved core genome, particularly in the regions encoding DNA replication and virion structural proteins. Of the ZZ1 proteins, 70, 64, 61, and 56% share up to 86, 85, 81, and 83% amino acid identity with Acj9, Acj61, 133, and Ac42 proteins, respectively. ZZ1 has a different number and types of tRNAs than the other 4 Acinetobacter phages, although some of the ZZ1-encoded tRNAs share high sequence similarity with the tRNAs from these phages. Over half of ZZ1-encoded tRNAs (5 out of 8) are related to optimal codon usage for ZZ1 proteins. However, this correlation was not present in any of the other 4 Acinetobacter phages. CONCLUSIONS: The comparative genomic analysis of these phages provided some new insights into the evolution and diversity of Acinetobacter phages, which might elucidate the evolutionary origin and host-specific adaptation of these phages.

Effects of lentivirus-mediated RNAi knockdown of NEDD9 on human lung adenocarcinoma cells in vitro and in vivo.

The aim of the present study was to investigate the biological behavior of lung adenocarcinoma A549 cells following transfection with NEDD9-specific lentiviral particles in vitro and in vivo. NEDD9-specific lentiviral particles were chemically synthesized and transfected into the human lung adenocarcinoma A549 cell line. NEDD9 mRNA and protein levels were determined by fluorescence quantitative RT-PCR and western blotting. Cell proliferation was evaluated using soft agar colony formation assays and flow cytometric analysis. Migration and invasion were evaluated by wound-healing and transwell assays and xenograft animal models. Transfection was successful, and expression levels of NEDD9 mRNA and protein in the lentivirus-NEDD9-siRNA group were downregulated. As indicated by soft agar colony formation assays, the number of clones in the siRNA group were significantly lower than the number of colonies in the blank and negative control groups (P<0.01). In addition, the percentage of cells in the S phase in the siRNA group was significantly lower than the percentages in the blank and negative control groups (P<0.05). Furthermore, as detected by cell migration and invasion assays, values of wound healing were increased and the number of invading cells were decreased in the siRNA group (both P<0.05). We also showed that lentivirus-mediated NEDD9-siRNA decreased the growth potential of subcutaneous A549 xenografts in vivo. These data imply that knockdown of the NEDD9 gene results in suppression of tumor cell proliferation, migration, invasion and cell growth in vitro and in vivo. Lentivirus-mediated NEDD9-siRNA may have potential therapeutic utility for human lung adenocarcinoma.

miR-1303 targets claudin-18 gene to modulate proliferation and invasion of gastric cancer cells.

BACKGROUND: MicroRNAs have emerged as important gene regulators and are recognized as important molecules in carcinogenesis. However, the effects of microRNA-1303 (miR-1303) on gastric cancer (GC) cells and the upstream regulation of GC-associated claudin-18 gene (CLDN18) remain unclear. miR-1303 may be involved in the tumorigenesis of GC by targeting CLDN18. AIMS: The purpose of this study was to explore the effect of miR-1303 targeting of CLDN18 on the proliferation, migration and invasion of human GC cells. METHODS: The expression of miR-1303 and claudin-18 in GC tissues and gastric cancer cell lines were detected by qRT-PCR and western blotting, respectively. CCK8 and colony formation assays were performed to study the influence of miR-1303 on the proliferation of the GC cell lines. Transwell and wound-healing assays were carried out to investigate the effect of miR-1303 on the invasion and migration of GC cell lines. Luciferase reporter assays, restore assays and western blotting were used to demonstrate whether CLDN18 is a direct target of miR-1303. RESULTS: miR-1303 was significantly overexpressed whereas claudin-18 was downregulated in GC tissues and cell lines, which was significantly associated with tumor size, location invasion, histologic type and tumor-node-metastasis stage. Cell proliferation rates were reduced, and cell invasion and migratory ability was significantly restricted in miR-1303 inhibitor-transfected groups. miR-1303 could bind to the putative binding sites in CLDN18 mRNA 3'-UTR and visibly lower the expression of claudin-18. The introduction of claudin-18 without 3'-UTR restored the miR-1303 promoting migration function. CONCLUSIONS: Downregulation of miR-1303 can inhibit proliferation, migration and invasion of GC cells by targeting CLDN18.

Serum miR-21 and miR-155 expression in idiopathic pulmonary fibrosis.

OBJECTIVE: To investigate the expression of serum miRNA-21(miR-21) and miRNA-155 (miR-155) in idiopathic pulmonary fibrosis (IPF). METHODS: A study including 65 patients with IPF and 65 similar age and gender healthy controls was performed. Serum specimens were collected from all subjects. Total RNA was extracted and the quantitative reverse transcription-polymerase chain reaction was used to measure serum miR-21 and miR-155 in both groups. Clinicopathologic features were assessed to determine associations with serum miR-21 and miR-155 concentrations. RESULTS: Serum miR-21 expression was significantly higher in IPF samples than in healthy controls (p < 0.01), while serum miR-155 expression did not show a statistically significant difference (p > 0.05). Forced vital capacity (FVC) and radiologic features were associated with miR-21 and miR-155 expression in serum (p < 0.05). Neither miR-21 nor miR-155 expression was statistically significantly associated with clinicopathologic parameters, such as gender (p > 0.05) and age (p > 0.05). CONCLUSION: These findings suggest that serum miR-21 is associated with IPF and the degree of damage indicated by FVC and radiologic examinations could correlate with miR-21 and miR-155 expression in serum. From another perspective, our study confirmed serum miRNA can be stable and detectable in serum of patients with IPF, which could prove useful as it could be considered as a new biomarker in serum for diagnosis and assessment of prognosis of IPF in the future.

MiR-21 down-regulation suppresses cell growth, invasion and induces cell apoptosis by targeting FASL, TIMP3, and RECK genes in esophageal carcinoma.

BACKGROUND: miR-21 is overexpressed in esophageal squamous cell carcinoma (ESCC) and is thought to be correlated with the development of the cancer. The target gene of miR-21 including FASL, TIMP3 and RECK is revealed by researchers. miR-21 may be involved in the tumorgenesis of ESCC by targeting FASL, TIMP3 and RECK. AIMS: The purpose of this study was to explore the mechanism of miR-21 in the development of ESCC. METHODS: miR-21 expression in ESCC and the matched non-malignant adjacent tissues (NMATs) was examined by qRT-PCR. Cell growth, cell apoptosis and cell invasion ability of EC9706 and EC-1 cells was examined after the cells were transfected with miR-21 inhibitor. The potential target genes of miR-21 including FASL, TIMP3 and RECK were examined by western blot and Luciferase reporter assay. RESULTS: miR-21 expression was increased significantly in ESCC tissues compared with NMAT. miR-21 down-regulation inhibits cell growth, cell invasion and induces cells to apoptosis. FASL, TIMP3 and RECK are direct targets of miR-21. CONCLUSIONS: miR-21 down-regulation inhibits cell growth, invasion and induces cells to apoptosis by targeting FASL, TIMP3 and RECK genes.

Effects of cyclin E gene silencing on the proliferation of esophageal cancer cell lines, EC9706, Eca109 and KYSE30.

In order to observe the effects of cyclin E gene silencing by small interfering RNA (siRNA) on the growth, proliferation, invasion and apoptosis of esophageal cancer cell lines, including EC9706, Eca109 and KYSE30, siRNA vectors targeting cyclin E gene were constructed and then transfected into the EC9706, Eca109 and KYSE30 human esophageal cancer cell lines. Cyclin E mRNA and protein expression were determined by RT-PCR and western blotting. Cell proliferation and clonality were detected using a CCK-8 test and soft agar colony formation assay. Cell cycle distribution, apoptosis and invasion of EC9706, Eca109 and KYSE30 cells were evaluated with flow cytometry and a transwell culture system. After siRNA vectors targeting the cyclin E gene were transfected into EC9706, Eca109 and KYSE30 cell lines, compared with blank and negative control groups, the expression of cyclin E mRNA and protein (P<0.01), colony-forming units and the number of cells penetrating the transwell membrane (P<0.05) were significantly decreased, the cells in the S and G2/M phase were reduced, the cells in the G0/G1 phase were increased and the apoptosis rate was increased (P<0.01) in the experimental groups. Cyclin E gene silencing effectively inhibits growth, proliferation and invasion of esophageal cancer cells.

Silencing Bmi-1 enhances the senescence and decreases the metastasis of human gastric cancer cells.

AIM: To evaluate the impact of Bmi-1 on cell senescence and metastasis of human gastric cancer cell line BGC823. METHODS: Two pairs of complementary small hairpin RNA (shRNA) oligonucleotides targeting the Bmi-1 gene were designed, synthesized, annealed and cloned into the pRNAT-U6.2 vector. After DNA sequencing to verify the correct insertion of the shRNA sequences, the recombinant plasmids were transfected into BGC823 cells. The expression of Bmi-1 mRNA and protein was examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. The effects of Bmi-1 knockdown on cell senescence and metastasis were determined by the ß-Gal activity assay and Boyden chamber assay, respectively. RESULTS: The double-stranded oligonucleotide fragments of Bmi-1 short interfering RNA (siRNA) cloned into pRNAT-U6.2 vector conformed to the inserted sequence. RT-PCR and Western blotting indicated that the expression levels of Bmi-1 gene mRNA and protein were markedly decreased in transfected BGC823 cells with pRNAT-U6.2-si1104 and pRNAT-U6.2-si1356, especially in transfected BGC823 cells with pRNAT-U6.2-si1104, compared with two control groups (empty vector and blank group). In particular, Bmi-1 protein expression was almost completely abolished in cells transfected with the recombinant vector harboring shRNA targeting the sequence GGAGGAGGTGAATGATAAA (nt1104-1122). Compared with untransfected cells and cells transfected with the empty vector, the mean percentage of senescent cells increased and the number of cells passing through the Matrigel decreased in cells transfected with the recombinant vectors. CONCLUSION: Silencing Bmi-1 by RNA interference can increase the senescent cell rate and effectively reduce the metastasis of gastric cancer cells.