OBJECTIVETo establish a colorectal cancer cell line with stable PRL-3 and CDH22 gene knock-down for investigating the role of PRL-3 and CDH22 genes in the carcinogenesis and metastasis of colorectal cancer.

METHODSA recombinant lentiviral vector targeting CDH22 gene was obtained using the pENTRTM/U6 construct and pLenti6/BLOCK-iT (TM)-DEST vector. The recombinant lentivirus was harvested from 293FT cells cotransfected with the optimized ViraPower(TM) Packaging Mix and the pLenti6/BLOCK-iT(TM)-DEST expression construct. SW480/PRL-3- cells were infected with the recombinant lentivirus targeting CDH22, and SW480 cells with stable PRL-3 and CDH22 knock-down were screened by blasticidin selection. PRL-3 expression in the cells was determined by real-time RT-PCR. RESULTS The titer of the lentivirus for the second infection was 8 x 10(5) U/ml. Seventeen positive clones were selected, among which the Clone 1 exhibited substantially down-regulated CDH22 and PRL-3 mRNA expressions.

CONCLUSIONSA human colorectal cancer cell line with stable PRL-3 and CDH22 gene knock-down has been established.

Cadherins ; genetics ; Cell Line, Tumor ; Clone Cells ; metabolism ; Colorectal Neoplasms ; genetics ; pathology ; Gene Expression Regulation, Neoplastic ; Gene Knockdown Techniques ; methods ; Humans ; Lentivirus ; genetics ; Neoplasm Proteins ; genetics ; Protein Tyrosine Phosphatases ; genetics ; RNA Interference ; RNA, Messenger ; genetics ; metabolism

OBJECTIVETo construct a recombinant lentivirus RNA interference (RNAi) vector carrying hTERT gene, and to obtain the titer of the lentiviral stock for investigating the expression in the eukaryotic cells and the effect on the hTERT gene silencing in the eukaryotic cells.

METHODSTwo complimentary oligos of small interference RNA (siRNA) with hairpin structures targeting the hTERT gene and a negative control were synthesized, then ligated with pLVTHM vector and sequenced. The recombinant vectors were then transfected with viral packaging mix into T293 cells, viral supernatant was harvested to determine the titer. U87 cells infected by virus were harvested and the expression of hTERT, telomerase activity and apoptosis were detected by reverse transcription-PCR(RT-PCR), TRAP assay and flow cytometry separately.

RESULTSSequencing data showed that the constructed plasmids contained the correct sequences of hTERT siRNA transcript templates. A vector producing cell line T293 was established, and the titer for transfection was obtained. RT-PCR and TRAP flow cytometry analyses demonstrated that hTERT shRNA expression construct could suppress the expression of hTERT and telomerase activity and induce apoptosis.

CONCLUSIONA lentivirus RNAi vector targeting hTERT gene was successfully constructed, which decreased the expression of hTERT and telomerase activity effectively and induced apoptosis. It has set up a research platform for the gene therapy of tumors which take hTERT as the target.

Base Sequence ; Cell Line ; Flow Cytometry ; Gene Knockdown Techniques ; methods ; Genetic Vectors ; genetics ; Humans ; Lentivirus ; genetics ; Molecular Sequence Data ; Oligodeoxyribonucleotides ; genetics ; metabolism ; Plasmids ; genetics ; metabolism ; RNA Interference ; RNA, Small Interfering ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Telomerase ; biosynthesis ; genetics

To study the inhibitory effect of Nogo-A shRNA on cell line PC12, the Nogo-A shRNA (short hairpin RNA, or shRNA) was designed and synthesized. The annealed shRNA template was inserted into plasmid pGenesil-1 containing enhanced green fluorescent protein (EGFP) gene by gene cloning technique to generate eukaryotic expression vector. The recombinant plasmid was transfected into PC12 cells by lipofecamine2000 and the mRNA and protein expression level of Nogo-A gene was detected by RT-PCR and Western blotting 48 h after the transfection. Gene sequencing showed that that the Nogo-A shRNA eukaryotic expression vector was successfully constructed. No significant change was found in the Nogo-A mRNA and protein expression level in empty vector-transfected group as compared with controls (P>0.05), while the expression level in shRNA-transfected group decreased significantly (P<0.05). It is concluded that the pGenesil-1/Nogo-AshRNA recombinant plasmid can effectively suppress the expression of Nogo-A gene in PC12 cells.
Cloning, Molecular ; Gene Knockdown Techniques/*methods ; Genetic Vectors ; Green Fluorescent Proteins/genetics ; Myelin Proteins/*genetics ; Myelin Proteins/metabolism ; PC12 Cells ; Plasmids ; RNA Interference ; RNA, Messenger/genetics ; RNA, Messenger/metabolism ; RNA, Small Interfering ; Transfection

Conventional lung cancer therapies are associated with poor survival rates; therefore, new approaches such as gene therapy are required for treating cancer. Gene therapies for treating lung cancer patients can involve several approaches. Among these, aerosol gene delivery is a potentially more effective approach. In this study, Akt1 kinase-deficient (KD) and wild-type (WT) Akt1 were delivered to the lungs of CMV-LucR-cMyc-IRES-LucF dual reporter mice through a nose only inhalation system using glucosylated polyethylenimine and naphthalene was administrated to the mice via intraperitoneal injection. Aerosol delivery of Akt1 WT and naphthalene treatment increased protein levels of downstream substrates of Akt signaling pathway while aerosol delivery of Akt1 KD did not. Our results showed that naphthalene affected extracellular signal-regulated kinase (ERK) protein levels, ERK-related signaling, and induced Clara cell injury. However, Clara cell injury induced by naphthalene was considerably attenuated in mice exposed to Akt1 KD. Furthermore, a dual luciferase activity assay showed that aerosol delivery of Akt1 WT and naphthalene treatment enhanced cap-dependent protein translation, while reduced cap-dependent protein translation was observed after delivering Akt1 KD. These studies demonstrated that our aerosol delivery is compatible for in vivo gene delivery.
Administration, Inhalation ; Aerosols ; Animals ; Gene Expression Regulation ; Gene Knockdown Techniques ; Gene Therapy/*methods ; Gene Transfer Techniques ; Genes, Reporter ; Injections, Intraperitoneal ; Luciferases/genetics/*metabolism ; Lung Diseases/*chemically induced ; Male ; Mice ; Mice, Transgenic ; Naphthalenes/administration & dosage/*toxicity ; Proto-Oncogene Proteins c-akt/*administration & dosage/genetics/*metabolism

OBJECTIVE: To explore the association between expression of ADAM17 and cetuximad resistance in human colorectal cancer SW480 cells. METHODS: The expression of ADAM17 was detected using Western blotting in different human colorectal cancer cell lines, and the cells highly expressing ADAM17 were selected as the target cells. SW480 cells were transfected with ADAM17-siRNA 1 and ADAM17-siRNA 2 and the changes in the expression of ADAM17 protein were detected using Western blotting. SW480 cells were exposed to cetuximad for 24 h and the cell apoptosis was analyzed using flow cytometry. Transwell assay was used to examine the migration ability of SW480 cells with different expression levels of ADAM17; Western blotting was used to analyze the changes in the expressions of AKT signaling pathway-related proteins in the treated cells. RESULTS: The baseline expressions of ADAM17 were significantly higher in SW480 cells than in the other human colorectal cancer cell lines tested ( < 0.05). Both ADAM17-siRNA 1 and 2 effectively reduced the expression of ADAM17 protein in SW480 cells. Knockdown of ADAM17 with siRNA 1 significantly increased the sensitivity of SW480 cells to tocetuximad ( < 0.05), obviously inhibited the cell proliferation, migration and invasion, and significantly reduced the expressions of p-EGFR and p-AKT in the cells ( < 0.001). CONCLUSIONS ADAM17 knockdown obviously inhibits EGFR-AKT signaling pathway and increases the sensitivity of SW480 cells to tocetuximad.
ADAM17 Protein ; genetics ; metabolism ; Antineoplastic Agents, Immunological ; pharmacology ; Apoptosis ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Cetuximab ; pharmacology ; Colorectal Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; Drug Resistance, Neoplasm ; genetics ; ErbB Receptors ; metabolism ; Gene Knockdown Techniques ; Humans ; Neoplasm Invasiveness ; Oncogene Protein v-akt ; metabolism ; RNA, Small Interfering ; Signal Transduction ; Transfection ; methods

OBJECTIVETo investigate the effect of ASCT2 gene (glutamine transporter) knock-down by shRNA on biological behaviors of colorectal cancer cells.

METHODSshRNA was transfected into colorectal cancer cells Lovo and SW480 to knockdown ASCT2 mediated by Lipofectamine 2000. Reverse transcription-PCR and Western blot were used to examine the mRNA and protein expression of ASCT2. MTT and transwell assay were used to determine the proliferation and invasiveness of Lovo and SW480 cells. Radioactive-tracer was used to detect the uptake of glutamine.

RESULTSASCT2 mRNA and protein levels were significantly down-regulated by shRNA in Lovo and SW480 cells(P<0.01). MTT and transwell assays showed that ASCT2 knock-down could significantly inhibit the proliferation of Lovo and SW480 cells (A490) and decrease the number of invasive Lovo and SW480 cells from the membrane (both P<0.01). The number of membrane Lovo cells in shASCT group and control group was 46.3±5.9 and 197.7±9.1, respectively while the number of membrane SW480 cells in shASCT group and control group was 29.7±3.8 and 139.0±9.5, respectively. Radioactive-tracer showed that shASCT2 transfection could significantly reduce the uptake of glutamine, with an inhibition rate of 79.15% in Lovo and 67.22% in SW480 cells (both P<0.01).

CONCLUSIONSASCT2 plays an oncogenic role in colonic cancer, and its promotion mechanism may be associated with glutamine metabolism. ASCT2 may be a novel therapeutic target of colonic cancer.

Amino Acid Transport System ASC ; drug effects ; genetics ; physiology ; Cell Line, Tumor ; physiology ; Cell Proliferation ; genetics ; Colorectal Neoplasms ; genetics ; physiopathology ; Down-Regulation ; drug effects ; Gene Knockdown Techniques ; methods ; Glutamine ; drug effects ; genetics ; physiology ; Humans ; Minor Histocompatibility Antigens ; drug effects ; genetics ; physiology ; Neoplasm Invasiveness ; genetics ; physiopathology ; Oncogenes ; drug effects ; genetics ; RNA, Messenger ; physiology ; RNA, Small Interfering ; pharmacology ; Transfection