Eukaryotic translation initiation factor 4G (eIF4G) is a scaffold component of eukaryotic translation initiation factor 4F (eIF4F) complex, which takes principal part in the initiating of protein synthesis. Both two subtypes (eIF4G1 and eIF4G2) of eIF4G were found to be closely related with various tumors. The eIF4G1 expression is significantly up-regulated in breast cancer, cervical cancer, nasopharyngeal carcinoma, lung squamous cell carcinoma, prostatic carcinoma and other malignant tumors, compared with those in adjacent tissues; and the eIF4G2 is obviously over-expressed in diffuse large B cell lymphoma and acute myeloid leukemia, but low-expressed in bladder transitional cell carcinoma. This paper reviews the progress in the study of the role of eIF4G in tumor genesis, development, diagnosis and prognosis.
Eukaryotic Initiation Factor-4G ; Humans ; Neoplasms ; Protein Biosynthesis ; Up-Regulation

OBJECTIVETo investigate the inhibitory effect of elemene on laryngeal carcinoma (Hep-2 cells) xenograft growth in nude mice and its mechanisms, and to explore the relationship between the expression of eukaryotic initiation factor families (eIF4E & eIF4G) and angiogenesis factors (bFGF & VEGF) after the administration of elemene.

METHODSHuman laryngeal carcinoma cells from Hep-2 cell strain were transplanted subcutaneously to BALB/c-nu/nu nude mice to produce tumors (42 nude mice were separated into seven groups to be treated by intraperitoneal injection). The tumor volume, tumor weight and tumor inhibition rate were evaluated, the expression of eIF4E, eIF4G, bFGF, VEGF and microvessel density were estimated by paraffin-embedded sections of seven groups' tumor samples analyzed utilizing immunohistochemical streptavidin peroxidase technique.

RESULTSElemene could inhibit the tumor growth in vivo. A significant suppression of tumor growth was observed when the dosage was increased. The tumor inhibition rates (IR) of elemene 50 mg/kg, 100 mg/kg and 200 mg/kg treated group were 5.2% , 41.7% and 50. 5% respectively. The IR of 100 mg/kg elemene (41.7%) was not significantly different with that of 3 mg/kg cisplatin (44.6%), and the IR of the drug combination (100 mg/kg elemene + 3 mg/kg cisplatin) was 51.2%. Compared with control groups the protein expression of eIF4E, eIF4G, bFGF and VEGF were significantly inhibited by elemene (P < 0.05), and the microvessel density in elemene treated groups decreased (P < 0.05). The tumor inhibition rate of combined elemene 100 mg/kg and cisplatin 3 mg/kg was 51.2%.

CONCLUSIONSElemene could inhibit the subcutaneous plantation of human laryngeal carcinoma in nude mice and its mechanism may be associated with inhibited expression of eIF families and angiogenesis factors. The combination of elemene and cisplatin could promote the synergistic effect on chemotherapy in the target tumor cells.

Animals ; Carcinoma, Squamous Cell ; blood supply ; pathology ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Eukaryotic Initiation Factor-4E ; metabolism ; Eukaryotic Initiation Factor-4G ; metabolism ; Fibroblast Growth Factor 2 ; metabolism ; Humans ; Laryngeal Neoplasms ; blood supply ; pathology ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Neovascularization, Pathologic ; Sesquiterpenes ; pharmacology ; Vascular Endothelial Growth Factor A ; metabolism ; Xenograft Model Antitumor Assays

OBJECTIVETo establish a nasopharyngeal carcinoma (NPC) cell line with stable EIF4G1 gene silencing induced by small interfering RNA (siRNA).

METHODSThe EIF4G1 mRNA levels in 8 NPC cell lines including 5-8F, 6-10B, C666-1, CNE1, CNE2, HNE1, HONE1, and SUNE1 were detected by fluorescence quantitative RT-PCR (QRT-PCR). The recombinant lentivirus shRNA expression plasmid targeting EIF4G1 gene was packaged into mature lentivirus by 293FT cells and used to infect 5-8F cells. After blasticidin selection of NPC cells with constant expression of the EIF4G1-siRNA, the efficiency of EIF4G1 mRNA expression interference was determined using QRT-PCR.

RESULTSThe 8 NPC cell lines showed differential expression of EIF4G1 mRNA, among which 5-8F cells had the highest EIF4G1 expression. The recombinant lentivirus plasmid pLenti6/BLOCK-iT-DEST/EIF4G1-shRNA was successfully constructed and verified by PCR and sequencing. The EIF4G1 mRNA level of 5-8F cells infected with shRNA-EIF4G1 lentivirus was significantly reduced as compared with the negative control and the blank control cells.

CONCLUSIONThe recombinant lentivirus vector pLenti6/BLOCK- iT-DEST/EIF4G1-shRNA we constructed results in marked downregulation of EIF4G1 mRNA expression and constant expression of EIF4G1-siRNA after infection of 5-8F cells.

Cell Line, Tumor ; Eukaryotic Initiation Factor-4G ; biosynthesis ; genetics ; Genetic Vectors ; genetics ; Humans ; Lentivirus ; genetics ; metabolism ; Nasopharyngeal Neoplasms ; genetics ; metabolism ; RNA Interference ; RNA, Messenger ; biosynthesis ; genetics ; RNA, Small Interfering ; genetics ; Transfection

To investigate whether transcription of hepatitis B virus (HBV) gene occurs in human sperm, total RNA was extracted from sperm of patients with chronic HBV infection (test-1), from donor sperm transfected with a plasmid containing the full-length HBV genome (test-2), and from nontransfected donor sperm (control), used as the template for reverse transcription-polymerase chain reaction (RT-PCR). Positive bands for HBV DNA were observed in the test groups but not in the control. Next, to identify the role of host genes in regulating viral gene transcription in sperm, total RNA was extracted from 2-cell embryos derived from hamster oocytes fertilized in vitro by HBV-transfected (test) or nontransfected (control) human sperm and successively subjected to SMART-PCR, suppression subtractive hybridization, T/A cloning, bacterial amplification, microarray hybridization, sequencing and the Basic Local Alignment Search Tool (BLAST) search to isolate differentially expressed genes. Twenty-nine sequences showing significant identity to five human gene families were identified, with chorionic somatomammotropin hormone 2 (CSH2), eukaryotic translation initiation factor 4 gamma 2 (EIF4G2), pterin-4 alpha-carbinolamine dehydratase 2 (PCBD2), pregnancy-specific beta-1-glycoprotein 4 (PSG4) and titin (TTN) selected to represent target genes. Using real-time quantitative RT-PCR (qRT-PCR), when CSH2 and PCBD2 (or EIF4G2, PSG4 and TTN) were silenced by RNA interference, transcriptional levels of HBV s and x genes significantly decreased (or increased) (P < 0.05). Silencing of a control gene in sperm did not significantly change transcription of HBV s and x genes (P > 0.05). This study provides the first experimental evidence that transcription of HBV genes occurs in human sperm and is regulated by host genes.
Animals ; Connectin/genetics* ; Cricetinae ; Eukaryotic Initiation Factor-4G/genetics* ; Gene Expression Regulation/genetics* ; Gene Silencing ; Growth Hormone/genetics* ; Hepatitis B Surface Antigens/genetics* ; Hepatitis B virus/genetics* ; Hepatitis B, Chronic/virology* ; Humans ; Hydro-Lyases/metabolism* ; Male ; Pregnancy-Specific beta 1-Glycoproteins/genetics* ; RNA, Viral/analysis* ; Spermatozoa/virology* ; Trans-Activators/genetics* ; Transcription, Genetic ; Transfection ; Viral Regulatory and Accessory Proteins