Biomedical subjects

Cui-fen Huang

Publications and source records attributed to Cui-fen Huang.

6 recordsLinked to original sources

PubMed2006

[Effects of exogenous ER beta expression on the cell growth properties of MCF-7 breast cancer cell line].

OBJECTIVE: To study the effects of exogenous ER beta on the growth of breast cancer MCF-7 cells under different treatment. METHODS: An eukaryotic expression vector containing 1.6 kb of human entire coding sequence of ER beta (pCDNA3-ER beta) was transfected into human breast cancer MCF-7 cells using lipofectamine 2000. The biological activity of ER beta was detected with the luciferase reporter containing estrogen responsive element (ERE) and the expression of ER beta protein by Western blot. The growth properties of MCF-7, pCDNA 3-transfected MCF-7 and pCDNA 3-ER beta-transfected MCF-7 cells under different treatment, including E2 (17beta-estradiol) and 4-OHT (4-hydroxytamoxifen), were observed. RESULTS: A stronger activation of the reporter by ER beta in the presence of E2 was observed in the pCDNA 3-ER beta-transfected MCF-7 cells than in the pCDNA 3-transfected MCF-7 and in MCF-7 cells. Western blot analysis showed that the protein level of ER beta in the pCDNA 3-ER beta-transfected MCF-7 cells was markedly increased. Exogenous ER beta expression did not change the growth properties and the morphology of MCF-7 cells under normal condition. The pCDNA 3-ER beta-transfected MCF-7 cells proliferated at the same rate as naive cells in the presence of 4-OHT, whereas a strong inhibition of the proliferation of the pCDNA 3-ER beta-transfected MCF-7 cells in the presence of E2 was observed. CONCLUSION: Exogenous ER beta expression does not increase the resistance to 4-OHT, and a strong inhibition of the proliferation may occur in the presence of E2.

Breast Neoplasms↗

PubMed2006

[An analysis of the features of HBx protein distributed in liver cells and its expression in E. coli].

OBJECTIVE: To investigate the features of HBx protein distributed in liver cells and its expression in E. coli. METHODS: The expression vectors encoding the full length HBx and its mutants were constructed by the routine molecular cloning method. HBx protein expression was detected using Western blotting. The distribution feature of HBx protein in liver cells was examined using the fluorescence confocal microscopy. A series of purified HBx fusion proteins were obtained by glutathione-sepharose 4B affinity chromatography. RESULTS: The expression vectors were successfully constructed for the full length HBx and its mutants. HBx was found distributed uniformly in the nuclei but granularly in the cytoplasm of the liver cells. Under optimal conditions, the mutant GST-HBx (72-120aa) was easily degraded. CONCLUSION: This study may provide a basis for further study on the biological function of HBx at the protein level.

Carcinoma, Hepatocellular↗

PubMed2005

[Malignant transformation of NIH3T3 cells induced by ectopic expression of PC-1 gene].

OBJECTIVE: To establish a mouse fibroblastic cell line stably transfected with PC-1 gene, and using such cell line to investigate tumor development and progression imposed by the ectopic expression of PC-1 gene. METHODS: Eukaryotic expression vector pcDNA3.1(-)/myc-his-pc-1 was transfected into mouse fibroblast cell line NIH3T3 by lipofectamine. Stable transfectants were selected by G418. The integration and expression of ectopic PC-1 gene were analyzed by PCR and RT-PCR. Cytomorphological analysis, MTT, soft agar colony formation and nude mice tumorigenesis assay were used to evaluate the effects of PC-1 gene expression on tumor development and progression. RESULTS: NIH 3T3 cell lines stably expressing PC-1 gene were successfully established and confirmed by PCR and RT-PCR analyses of the integration and expression of ectopic PC-1 gene. Comparing with the parental cell line and cells transfected with control vector, the PC-1 gene transfectants acquired several phenotypes of transformed cells: increasing growth rate, ability to grow and form cell colonies on soft agar, and becoming tumorigenic in nude mice. CONCLUSION: Ectopic expression of PC-1 gene in NIH3T3 cells can induce malignant transformation of mouse fibroblastic cells both in vitro and in vivo.

Animals↗

PubMed2003

A human TERT C-terminal polypeptide sensitizes HeLa cells to H2O2-induced senescence without affecting telomerase enzymatic activity.

We have constructed a 27-kDa hTERT C-terminal polypeptide (hTERTC27) devoid of domains required for telomerase activity and demonstrated that it is capable of nuclear translocation/telomere-end targeting. Here we showed that expression of a low level of hTERTC27 renders hTERT positive HeLa cells sensitive to H(2)O(2)-induced oxidative stress and subsequent cell senescence. The senescence-associated gene, the cyclin/cdk inhibitor p21(Waf1), was up-regulated. This occurs without changing the expression of endogenous hTERT, causing significant telomere shortening or inhibiting telomerase activity. Results from this study suggest for the first time that in addition to telomerase activity, the C-terminus of hTERT also plays a role in hTERT-mediated cellular resistance to oxidative stress.

Cellular Senescence↗

PubMed2003

[Construction of ERbeta expression vector and its function in different cancer cells].

OBJECTIVE: To construct an ERbeta expression vector and study its expression and function in different cancer cells. METHODS: Standard PCR was used to amplify the full-length coding sequence of ERbeta. The amplified ERbeta gene was cloned into the eukaryotic expression vector pCDNA3, generating pCDNA3-ERbeta. The ERbeta expression was detected by Western blot and in vitro translation. The biological activity of ERbeta was detected by transfecting the pCDNA3-ERbeta into SV40-transformed embryonic kidney cell line 293T,breast cancer cell lines MDA-MB-435, MDA-MB-436, SKBR3, and prostate cancer cell line PC-3, with reporters containing estrogen response elements. RESULTS: The recombinant plasmid pCDNA3-ERbeta was confirmed by restriction analysis to contain the ERbeta gene. The 63 000 ERbeta expression was shown by Western blot and further confirmed by in vitro translation. The ERbeta expression in different cancer cells was demonstrated to stimulate the expression of the reporters containing estrogen response elements, ERE and C3. CONCLUSION: ERbeta protein is successfully expressed and has biological activity, laying solid foundation for further study on its role in cancer cells.

Breast Neoplasms↗

PubMed2002

[Expression of PC-1 gene in tumor tissues, cloning and analysis of its putative promoter region].

BACKGROUND & OBJECTIVE: PC-1 is a novel gene which is overexpressed in bone metastasis and androgen independent prostate cancer cell line C4-2. The objective of this study was to evaluate the expression level of PC-1 gene in multiple human tumor and normal tissues, and clone a series of putative PC-1 gene promoter regions and analyze their promoter activities. METHODS: PC-1 gene specific DNA sequence was used as probe to hybridize with total RNA from 10 pairs of tumor and normal tissues; The C4-2 cell genomic DNA was used as a template in the polymerase chain reaction to amplify PC-1 upstream regions from the translation initiation codon. The PCR product was directly cloned into the luciferase reporter vector pGL3-basic. C4-2 cells were transiently transfected with above recombinant plasmids and the putative promoter activities were analyzed by luciferase assay. RESULTS: PC-1 gene expression level is remarkable higher in multiple tumor tissues than in their matched normal tissues; there is no promoter activity in the 340 bp fragment from the upstream of initiation codon, while 1099 bp, 1337 bp, 1579 bp, 1831 bp, and 4939 bp fragments had the promoter activities. CONCLUSION: The PC-1 gene expression is specifically activated in multiple human tumor tissues, suggesting that PC-1 gene expression might be involved in cancer development. Our primary data shows that the highest promoter activity of PC-1 gene is within the 4939 bp DNA fragment and maybe there exists an enhancer element between the 1831 bp and 4939 bp area.

Base Sequence↗