RhoC induces differential expression of genes involved in invasion and metastasis in MCF10A breast cells.
Inflammatory breast cancer (IBC) is the most deadly form of breast cancer in humans presumably due to its ability to metastasize from its inception. In our laboratory, overexpression of RhoC GTPase was observed to be specific for IBC tumors, but not for stage-matched, non-IBC tumors. RhoC is known to contribute to an IBC-like phenotype in HPV-E6E7 immortalized breast cells. To further study the effect of RhoC overexpression on IBC metastasis, we generated stable transfectants of spontaneous immortalized mammary epithelial cells (MCF10A) overexpressing wild-type RhoC or a constitutively active RhoC mutant (G14V). Both the RhoC wild type and the G14V transfectants were highly invasive and proliferated more rapidly compared to vector-only control clones. Overexpression of RhoC led to an increase in actin stress fiber and focal adhesion contact formation. Comparative microarray analysis of these clones further revealed that RhoC overexpression upregulated 108 genes whereas seven genes were down-regulated. We have further verified by quantitative RT-PCR that genes involved in cell proliferation, invasion/adhesion, and angiogenesis were modulated by RhoC. This work suggests strong candidates for the downstream oncogenic functions of RhoC.
Department of Internal Medicine, Division of Hematology and Oncology, University of Michigan, Ann Arbor, MI 48109-0948, USA.
Mei
M
Wu
Zhi-Fen
ZF
Wu
Chandan
C
Kumar-Sinha
Arul
A
Chinnaiyan
Sofia D
SD
Merajver
D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D042361:Mammary Glands, Human / Q000473:pathology*; D008856:Microscopy, Fluorescence; D009361:Neoplasm Invasiveness; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014407:Tumor Cells, Cultured; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000502:physiology*; D000075024:rhoC GTP-Binding Protein
C066690:RHOC protein, human; D020741:rho GTP-Binding Proteins; D000075024:rhoC GTP-Binding Protein