Abstract | PURPOSE: EXPERIMENTAL DESIGN: We investigated the expression levels of hnRNP G protein in normal, precancerous, and malignant oral tissues by in situ immunohistochemistry. In addition, wild-type or mutant hnRNP G was ectopically overexpressed in HOSCC cells and their effects on cellular replication kinetics, colonogenic efficiency, anchorage-independent growth, and in vivo tumorigenicity were determined. RESULTS: In situ immunohistochemical staining showed robust presence of hnRNP G in the basal cell layers of normal oral epithelium but the level of its staining was markedly reduced in dysplastic or cancerous tissues. Ectopic expression of wild-type hnRNP G in cancer cells lacking hnRNP G expression or containing mutant hnRNP G resulted in severe retardation of proliferation, reduction of colonogenic efficiency, loss of anchorage-independent growth, and reduction of in vivo tumorigenicity in immunocompromised mice. In addition, hnRNP G overexpression led to up-regulation of the expression of TXNIP, a cell cycle inhibitory gene, and significantly reduced the expression of the genes that promote cellular proliferation, such as EGR1, JUND, JUNB, FOS, FOSL1, ROS, and KIT. CONCLUSIONS: These results indicate that hnRNP G is a tumor suppressor against HOSCC but its mechanisms of action remain to be further investigated.
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Authors | Ki-Hyuk Shin, Mo K Kang, Reuben H Kim, Russell Christensen, No-Hee Park |
Journal | Clinical cancer research : an official journal of the American Association for Cancer Research
(Clin Cancer Res)
Vol. 12
Issue 10
Pg. 3222-8
(May 15 2006)
ISSN: 1078-0432 [Print] United States |
PMID | 16707624
(Publication Type: Journal Article, Research Support, N.I.H., Extramural)
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Chemical References |
- Heterogeneous-Nuclear Ribonucleoproteins
- RBMX protein, human
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Topics |
- Animals
- Carcinoma, Squamous Cell
(genetics, physiopathology)
- Cell Adhesion
- Cell Proliferation
- Cell Transformation, Neoplastic
- Down-Regulation
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic
(drug effects)
- Heterogeneous-Nuclear Ribonucleoproteins
(biosynthesis, genetics, physiology)
- Humans
- Immunocompromised Host
- Immunohistochemistry
- Mice
- Mouth Neoplasms
(genetics, physiopathology)
- Precancerous Conditions
- Reverse Transcriptase Polymerase Chain Reaction
- Tumor Cells, Cultured
- Up-Regulation
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