OBJECTIVETo study the mechanism of the cellular proteins involved in the process of replication of hepatitis C virus (HCV) negative-strand RNA.

METHODSUltraviolet (UV) cross-linking was used to identify the cellular proteins that would bind to the 3'-end of HCV negative-strand RNA. Competition experiment was used to confirm the specificity of this binding, in which excess nonhomologous protein and RNA transcripts were used as competitors. The required binding sequence was determined by mapping, then the binding site was predicted through secondary structure analysis.

RESULTSA cellular protein of 45 kD (p45) was found to bind specifically to the 3'-end of HCV negative-strand RNA by UV cross-linking. Nonhomologous proteins and RNA transcripts could not compete out this binding, whereas the unlabeled 3'-end of HCV negative-strand RNA could. Mapping of the protein-binding site suggested that the 3'-end 131-278nt of HCV negative-strand RNA was the possible protein-binding region. Analysis of RNA secondary structure presumed that the potential binding site was located at 194-GAAAGAAC-201.

CONCLUSIONThe cellular protein p45 could specifically bind to the secondary structure of the 3'-end of HCV intermediate negative-strand RNA, and may play an important role in HCV RNA replication.

Binding Sites ; Hepacivirus ; genetics ; Nucleic Acid Conformation ; RNA, Viral ; chemistry ; metabolism ; RNA-Binding Proteins ; analysis ; metabolism ; Virus Replication

OBJECTIVETo study the immunophenotype and differential diagnosis of Hodgkin's lymphoma (HL).

METHODFifty six cases originally diagnosed as HL were re-evaluated according to lymphoma classification of WHO 2000 on paraffin sections using SP immunohistochemistry.

RESULTSAmong the 56 cases, 47 met the WHO criteria for HL, 8 were NHL and 1 metastatic tumor. Of the 47 HL cases, 2 were nodular lymphocyte predominant HL (NLPHL), 43 classical Hodgkin's lymphoma (CHL) and 2 unclassified HL, and of the 8 cases reclassified as NHL, 6 were T-cell rich B-cell lymphoma (TCRBCL) and 2 anaplastic large cell lymphoma (ALCL). In NLPHL cases, L&H cells were CD(20)(+), CD(15)(-) and CD(30)(-); CD(57)(+) cells and small B-lymphocytes predominated the background infiltration. Diagnostic R-S cells and other tumor cells in 43 cases of CHL were positive for CD(30) (100%), CD(15) (81%) and CD(20) (7%). Six cases of TCRBCL were negative for CD(15) and CD(30). Two cases of ALCL were positive for CD(30), ALK-1 and CD(3), and negative for CD(15) and CD(20). The reactive inflammatory infiltration in CHL and TCRBCL was rich in TIA-1 positive cytotoxic lymphocytes, and CD(57)(+) cells were rarely encountered.

CONCLUSIONCombining the immunophenotype of tumor cells and background cells with morphologic criteria are more helpful for classification of HL, and discrimination between NLPHL, CHL and TCRBCL.

Antigens, CD ; analysis ; Diagnosis, Differential ; Hodgkin Disease ; immunology ; metabolism ; pathology ; Humans ; Immunohistochemistry ; Immunophenotyping ; Membrane Proteins ; analysis ; Mucin-1 ; analysis ; Poly(A)-Binding Proteins ; Proteins ; RNA-Binding Proteins ; analysis ; T-Cell Intracellular Antigen-1

OBJECTIVETo investigate the expression of nesfatin-1/NUCB2 and ghrelin in the gastric mucosa of rats with intrauterine growth retardation (IUGR) and its significance.

METHODSThe IUGR animal model was established by feeding rats low-protein diets during their pregnancy. Newborn rats were divided into catch-up growth, non-catch-up growth and control groups. Protein and mRNA levels of nesfatin-1/NUCB2 and ghrelin in the gastric mucosa of rats were determined by RT-PCR and Western blot, respectively.

RESULTSNesfatin-1/NUCB2 mRNA and protein were expressed in the gastric mucosa of rats immediately after birth, and their expression increased in an age-dependent manner in all three groups. Furthermore, the level of nesfatin-1/NUCB2 in the catch-up growth group was higher than that in the control group before weaning, whereas there was no significant difference in nesfatin-1/NUCB2 expression between the two groups after weaning. The level of nesfatin-1/NUCB2 in the non-catch-up growth group was lower than that in the catch-up growth group during the whole observation period. The level of ghrelin in the catch-up growth group was higher than that in the control group starting from day 12 after birth, whereas there was no significant difference in ghrelin expression between the two groups after weaning. The level of ghrelin in the non-catch-up growth group was lower compared with those in the catch-up growth and control groups from days 12 to 28 after birth.

CONCLUSIONSNesfatin-1 and ghrelin are co-expressed in the gastric mucosa of rats with IUGR after birth and interact with each other to produce long-term nutritional regulation.

Age Factors ; Animals ; Calcium-Binding Proteins ; analysis ; genetics ; DNA-Binding Proteins ; analysis ; genetics ; Female ; Fetal Growth Retardation ; metabolism ; Gastric Mucosa ; chemistry ; Ghrelin ; analysis ; genetics ; Male ; Nerve Tissue Proteins ; analysis ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the significance of Rac subfamily members in the gastrointestinal carcinogenesis and progression.

METHODSThe mRNA expression of Rac1, Rac2 and Rac3 in 12 kinds of gastrointestinal cancer cell lines was examined by semi-quantitative RT-PCR. The activities of Rac1 protein in 5 kinds of gastric cancer cell lines were tested by pull-down assay.

RESULTSCompared with the normal gastric mucosa and intestinal epithelial cell line, the mRNA expression of Rac1 and Rac3 was up-regulated in most of gastrointestinal cancer cell lines. The activities of Rac1 protein increased markedly in gastric cancer cell lines.

CONCLUSIONThe increased mRNA expression of Rac1 and Rac3 in gastrointestinal cancer cell lines and the abnormal activation of Rac1 protein in gastric cancer cell lines might be correlated with the carcinogenesis of gastrointestinal cancer.

Cell Line, Tumor ; Gastrointestinal Neoplasms ; metabolism ; Humans ; RNA, Messenger ; analysis ; Reverse Transcriptase Polymerase Chain Reaction ; rac GTP-Binding Proteins ; genetics ; rac1 GTP-Binding Protein ; analysis ; genetics

To investigate the change of telomerase activity and human telomerase reverse transcriptase (hTERT) gene expression in HL-60 cells transfected with wild type p53 gene, wild type p53 gene was introduced into HL-60 cells by Lipofectin transfection. Apoptosis was analyzed by TUNEL assay. Telomerase activity and the level of hTERT mRNA were detected by telomeric repeat amplification protocol (TRAP)-ELISA and RT-PCR, respectively. The results showed that the apoptotic rate of HL-60-pN53cG cells was 8.3% and 21.0% respectively after cultured at 32.5 degrees C for 24 h and 72 h. The level of hTERT mRNA was decreased to 68.4% and 55.8% and telomerase activity to 27.3% and 8.9% of control value in HL-60-pN53cG cells at the same points. In conclusions, hTERT mRNA and telomerase activity were down-regulated in HL-60 cells transfected with p53 gene. This may be one of mechanisms of apoptosis induced by wild type p53 gene.
Apoptosis ; DNA-Binding Proteins ; Gene Expression ; Genes, p53 ; physiology ; HL-60 Cells ; Humans ; RNA, Messenger ; analysis ; Telomerase ; genetics ; metabolism

OBJECTIVETo investigate the osteoblast-like characteristics of human periodontal ligament cells affected by elastic stress in vitro, and the role of corebinding factor a 1 (cbfa1) in alveolar bone formation during orthodontic tooth movement.

METHODSRat dig-labeled cbfa1 cDNA probe was prepared from SD rat osteoblasts cultured in vitro. Human periodontal ligament cells were cultured on the elastic bottom plate and stimulated by elastic stress using mechanical loading system for cultured cells in vitro. The expression of cbfa1 mRNA was detected by in situ hybridization method.

RESULTSCbfa1 mRNA express in human periodontal ligament cells stimulated by elastic stress and did not express in normal human periodontal ligament cells.

CONCLUSIONIt is suggested that elastic stress plays a role in the differentiation process from human periodontal ligament cells to osteoblast-like cells. Cbfa1 is a transcription factor in alveolar bone remodeling during orthodontic tooth movement.

Adolescent ; Animals ; Cells, Cultured ; Child ; Core Binding Factor alpha Subunits ; DNA-Binding Proteins ; genetics ; Elasticity ; Humans ; Periodontal Ligament ; cytology ; metabolism ; RNA, Messenger ; analysis ; Rats ; Transcription Factors ; genetics

Animals ; Carcinoma, Hepatocellular ; enzymology ; DNA-Binding Proteins ; Disease Models, Animal ; Liver Neoplasms ; enzymology ; Male ; RNA ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Telomerase ; genetics ; metabolism

OBJECTIVETo investigate telomerase gene expression in precancerous mammary lesion, such as atypical ductal hyperplasia and breast cancer and to study the relationship between expression and malignant transformation.

METHODSExpression of human telomerase genes (hTR) and human reverse transcriptase gene (hTRT) in 76 cases of mammary tissue was evaluated using in situ hybridization and included 50 cases of mammary hyperplasia, 6 of which were benign hyperplasia, 9 were mild atypical hyperplasia, 12 were moderate atypical hyperplasia, 23 were severe atypical hyperplasia and 26 were mammary cancer.

RESULTSThe expressions of hTR and hTRT mRNA were much weaker or negative in benign hyperplasia (16.6%, 0), weak to mild moderate in atypical hyperplasia (22.2%, 11.1%, 33.3%, 25.0%), strong in severe atypical hyperplasia (60.9%, 52.1%), and significantly strong in mammary cancer (88.5%, 80.8%). The difference between mild-moderate atypical hyperplasia, invasive ductal carcinoma and severe atypical hyperplasia was significant (P < 0.05) and the difference between severe atypical hyperplasia and intraductal carcinoma was not significant (P > 0.05).

CONCLUSIONTelomerase genes (hTR and hTRT) expressions are related to the transformation of atypical hyperplasia. Activated telomerase may play a role in mammary cancer development.

Breast ; metabolism ; pathology ; Breast Neoplasms ; genetics ; pathology ; DNA-Binding Proteins ; Female ; Gene Expression ; Humans ; Precancerous Conditions ; genetics ; pathology ; RNA ; genetics ; physiology ; RNA, Messenger ; analysis ; Telomerase ; genetics ; physiology

OBJECTIVETo investigate the expression of programmed cell death 4 (PDCD4) protein and its clinicopathological significance in human pancreatic cancer.

METHODSImmunohistochemistry was used to examine the expression of PDCD4 protein in 69 specimens of pancreatic cancer and Western blot in 8 fresh specimens.

RESULTSThe expression of PDCD4 protein was significantly lower in all 8 fresh pancreatic cancer tissues than that in non-cancerous tissues detected by Western blot. Compared with non-cancerous pancreatic tissue (> 80% of positive cells), low PDCD4 expression was shown in 69 pancreatic cancer tissues (< 30% of positive cells in 36 cases and 30%-80% of positive expression cells in 33 cases). In the 33 cases with 30% and 80% of positive expression cells, the expression rates of PDCD4 protein were 57.6%, 24.2%, and 18.2% in well, moderately, and poorly differentiated cancers, respectively. In the 36 cases less than 30% of positive expression cells, however, the expression rate of PDCD4 protein in well, moderately, and poorly differentiated cases were 19.4%, 41.7%, and 38.9%, respectively. 67.4% (15/23) of the moderately differentiated cases and 70% (14/20) of the poorly differentiated cases showed < 30% of positive expression cells. Only 26.9% (7/26) of the well differentiated cases, however, showed < 30% of positive expression cells, indicating that low PDCD4 expression was associated with histological grade (P < 0.01). There was no relationship between PDCD4 expression and other clinicopathological parameters including patients' sex, age, and TNM stage.

CONCLUSIONSExpression of PDCD4 protein is low in human pancreatic cancer and is correlated with the differentiation levels of human pancreatic cancer. PDCD4 may play an important role in the occurrence and development of pancreatic carcinomas.

Adult ; Aged ; Apoptosis Regulatory Proteins ; biosynthesis ; Biomarkers, Tumor ; analysis ; Blotting, Western ; Female ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Pancreatic Neoplasms ; metabolism ; pathology ; RNA-Binding Proteins ; biosynthesis

Cyclic AMP Response Element-Binding Protein ; DNA ; analysis ; genetics ; Female ; Humans ; Infant ; Male ; Muscular Atrophy, Spinal ; genetics ; Nerve Tissue Proteins ; genetics ; Polymerase Chain Reaction ; RNA-Binding Proteins ; SMN Complex Proteins