Abstract
Cyr61 (CCN1) is a member of the CCN protein family; these secreted proteins are involved in diverse biological processes such as cell adhesion, angiogenesis, apoptosis, and either growth arrest or growth stimulation depending on the cellular context. We studied the role of Cyr61 in endometrial tumorigenesis. Levels of Cyr61 were decreased in endometrial tumors compared with normal endometrium. Knockdown of Cyr61 expression by RNA interference in a well differentiated endometrial adenocarcinoma cell line (Ishikawa) stimulated its cellular growth. Conversely, overexpression of the protein in the undifferentiated AN3CA endometrial cancer cell line decreased their growth concurrently with increased apoptosis in liquid culture. These same cells had decreased clonogenic capacity and a nearly complete loss of tumorigenicity in vivo. Furthermore, partially purified Cyr61 suppressed growth of endometrial cancer cells. The increased apoptosis in these endometrial cancer cells with forced overexpression of Cyr61 was associated with elevated expression of the pro-apoptotic proteins Bax, Bad, and TRAIL (tumor necrosis factor receptor-associated ligand). Cyr61-induced caspase-3 activation and depolarization of mitochondrial membrane. In summary, endometrial cancer cells have decreased expression of Cyr61 compared with normal endometrium, and this lowered expression may provide the transformed cells a growth advantage over their normal counterpart.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Adenocarcinoma / metabolism
-
Apoptosis
-
Apoptosis Regulatory Proteins
-
Blotting, Western
-
Carrier Proteins / metabolism
-
Caspase 3
-
Caspases / metabolism
-
Cell Cycle
-
Cell Differentiation
-
Cell Line, Tumor
-
Cell Proliferation
-
Cell Separation
-
Culture Media, Conditioned / pharmacology
-
Cysteine-Rich Protein 61
-
Down-Regulation
-
Endometrial Neoplasms / metabolism*
-
Endometrium / metabolism
-
Enzyme Activation
-
Female
-
Flow Cytometry
-
Gene Silencing
-
Genes, Reporter
-
Humans
-
Immediate-Early Proteins / metabolism
-
Immediate-Early Proteins / physiology*
-
Immunoblotting
-
Intercellular Signaling Peptides and Proteins / metabolism
-
Intercellular Signaling Peptides and Proteins / physiology*
-
Intracellular Membranes / metabolism
-
Ligands
-
Membrane Glycoproteins / metabolism
-
Membrane Potentials
-
Mitochondria / metabolism
-
Proto-Oncogene Proteins c-bcl-2 / metabolism
-
RNA / metabolism
-
RNA Interference
-
RNA, Messenger / metabolism
-
Reverse Transcriptase Polymerase Chain Reaction
-
TNF-Related Apoptosis-Inducing Ligand
-
Time Factors
-
Transfection
-
Tumor Necrosis Factor-alpha / metabolism
-
bcl-2-Associated X Protein
-
bcl-Associated Death Protein
Substances
-
Apoptosis Regulatory Proteins
-
BAD protein, human
-
BAX protein, human
-
CCN1 protein, human
-
Carrier Proteins
-
Culture Media, Conditioned
-
Cysteine-Rich Protein 61
-
Immediate-Early Proteins
-
Intercellular Signaling Peptides and Proteins
-
Ligands
-
Membrane Glycoproteins
-
Proto-Oncogene Proteins c-bcl-2
-
RNA, Messenger
-
TNF-Related Apoptosis-Inducing Ligand
-
TNFSF10 protein, human
-
Tumor Necrosis Factor-alpha
-
bcl-2-Associated X Protein
-
bcl-Associated Death Protein
-
RNA
-
CASP3 protein, human
-
Caspase 3
-
Caspases