1,721,029 research outputs found
Morphological Localization of Apolipoproteins and Their mRNA by Immunocytochemistry and in Situ Nucleic Acid Hybridization
No full textFunctional Analysis of Ebv in Nasopharyngeal Carcinoma Cells
No full textA membrane invasion culture system was used to study the ability of EBV to enhance invasion and migration of nasopharyngeal carcinoma (NPC) cells. Semi-reverse transcriptase-PCR analysis of matrix proteinases and angiogenic factors from EBV-infected, or EBV-positive (EBV+) , cells demonstrated different degrees of elevated gene expression. In our animal model, EBV+ tumors grew faster and larger than EBV-free, or EBV-negative ( EBV-), tumors and also had clonal EBV terminal repeat sequences. Double- localization of EBV and certain host proteins in EBV+ tumors and biopsy specimens demonstrated that EBV up-regulates host genes only in cells that express those genes but not in cells that do not express them. Double- localization of EBV and host genes in NPC biopsy specimens all showed EBV- tumor cells expressing those host genes. Our data strongly suggest that EBV infection enhances progression of NPC tumor growth. They do not rule out a role for EBV infection in the induction and early promotion of NPC development. Unidentified factors may also enhance NPC tumor growth independent of the effects of EBV
Synthesis and Antitumor Evaluation of Water-Soluble Derivatives of Glyfoline
No full textThree types of water-soluble derivatives of the antitumor agent glyfoline : hydrochloride salts of 6-O-(N,N- dimethylaminoalkyl) glyfoline (Type 1), triethanolamine salts of glyfoline-6-O-alkylcarboxylate (Type 2), and hydrochloride salts of glyfoline-6-O-carbamate (Type 3), were synthesized for evaluation of their antitumor activities. Among these compounds, the triethanolamine salt of 6-O-(3-carboxypropyl)glyfoline (13) showed potent antitumor efficacy in mice bearing nasopharyngeal carcinoma( NPC) xenograft
Epstein–Barr Virus: New Research in Epithelial Carcinoma
No full textEpstein-Barr virus (EBV) can not be detected in untransformed squamous metaplastic epithelia of nasophparynx, but can be detected as an episomal form in certain nasopharyngeal carcinoma (NPC) biopsy specimens and cell lines. In the latter only a
subpopulation of NPC cells contains EBV DNA. It appears only in the early passages,
but disappears in all lines after 30 passages. EBV can not infect NPC cells and other
transformed epithelial cells directly, but can only infect the transformed epithelial cells if
the latter express IgA receptor (IgAR) through IgAR mediated endocytosis. EBVinfected
(EBV+) NPC cells show clonal terminal repeats of EBV DNA. EBV enhances
the proliferation rate, invasion activity and the expressions of some growth factors and
their receptors, the cytokines, invasion and metastasis-related genes in vitro.
Untransformed squamous metaplastic epithelia of nasopharynx do not express EBV
receptor or IgAR. The IgAR expression and EBV infection in severe dysplastic epithelia
and carcinoma in situ of nasopharynx are unusual. But about 70 to 80% of tumor cells in
each EBV+ NPC case are infected by EBV. The EBV+ NPC cells in the biopsy specimens
have a geographical distribution with areas of clonal expansion and some EBV+
lymphocytic infiltration. Each biopsy specimen contains 4 types of NPC cells: tumor
cells do not express IgAR and not contain EBV DNA; tumor cells express strong IgAR and contain EBV or not; tumor cells express very weak or no IgAR but contain EBV
DNA. The EBV+ xenografts in the SCID mice grow faster and bigger than the EBVgrafts.
The EBV+ tumor mass also has a clonal terminal repeats of EBV DNA sequence.
In the EBV- NPC xenograft, a fraction of the cells expresses moderate EGFR protein.
However, in EBV+ xenograft, some tumor cells contain both EBV signal and strong
EGFR protein expression, but other fraction of those tumor cells only contain EBV signal without EGFR protein. The same phenomenon has also presented in the double
localization of EBV signal and MDM2 protein. The EBV latent membrane protein (LMP-1) in the NPC cells can not regulated the host gene expression which is not
expressed in the host cells, but can indirectly regulated certain host gene expression which are expressed in the host cells. The major function of EBV in infected NPC cells is
to enhance tumor cell progression but less likely to play a role as an initiator or promoter in NPC pathogenesis
The Detection of Low Level of Human Papilloma Virus Type 16 DNA Sequences in Cancer Cell Lines Derived from Two Well-Differentiated Nasopharyngeal Cancers
No full text
Estrogen Induction of Very Low Density Apolipoprotein II Synthesis, A Major Yolk Protein in the Avian Liver Involves the Recruitment of Hepatocytes in the Estrogenic Response
No full text- …
