RUNX3 protein is overexpressed in human epithelial ovarian cancer
ABSTRACT RUNX family genes, including RUNX3, are developmental regulators that are important in human cancers. The purpose of this study was to evaluate expression and oncogenic potential of RUNX3 in ovarian carcinoma.
Immunohistochemical staining was performed on 60 malignant, 14 borderline, and 5 normal ovarian specimens. Correlation between RUNX3 expression with tumor histology was performed. RUNX3 expression was evaluated by quantitative real-time polymerase chain reaction (QRT-PCR) in microdissected normal and malignant epithelial ovarian tissues. Cell proliferation and viability studies were performed on cells expressing RUNX3 by lentiviral infection and cells with silenced RUNX3 expression by siRNA.
RUNX3 expression by immunohistochemistry was higher in serous ovarian carcinomas versus normal ovarian epithelium (P<0.001). Immunofluorescent staining confirmed upregulation of cytoplasmic RUNX3 in ovarian cancer cell lines and tissues. QRT-PCR showed higher RUNX3 mRNA expression in microdissected borderline and malignant ovarian tumor tissues compared with the normal ovarian surface epithelial cells (HOSE) (P=0.006 and P=0.023). Forced RUNX3 expression by lentiviral gene delivery in ovarian cancer cells, SKOV3, that initially showed undetectable RUNX3 expression, resulted in increased cell viability (P=0.043). Silencing RUNX3 expression by siRNA transfection into ovarian cancer cells, OVCAR429, initially expressing high levels of endogenous RUNX3 resulted in a decrease in proliferation (P=0.021).
These results suggest that RUNX3 has a role in cell proliferation and viability in ovarian cancer.
- SourceAvailable from: Ori Brenner
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- "Equally significant, this scenario was not implicated by any, not even a single one, of the 286 published papers that based their research on the correctness of Li et al and went on to postulate loss of Runx3 expression in normal GIT Ep to explain the pathogenesis of various types of cancer. On the contrary, in several epithelial cancers an upregulation of RUNX3 expression was observed and in these cases RUNX3 is considered an oncogene (Carvalho et al, 2005; Lee et al, 2011; Nevadunsky et al, 2009; Salto-Tellez et al, 2006). "
ABSTRACT: The Runx3 transcription factor regulates cell fate decisions during embryonic development and in adults. It was previously reported that Runx3 is strongly expressed in embryonic and adult gastrointestinal tract (GIT) epithelium (Ep) and that its loss causes gastric cancer. More than 280 publications have based their research on these findings and concluded that Runx3 is indeed a tumour suppressor (TS). In stark contrast, using various measures, we found that Runx3 expression is undetectable in GIT Ep. Employing a variety of biochemical and genetic techniques, including analysis of Runx3-GFP and R26LacZ/Runx3(Cre) or R26tdTomato/Runx3(Cre) reporter strains, we readily detected Runx3 in GIT-embedded leukocytes, dorsal root ganglia, skeletal elements and hair follicles. However, none of these approaches revealed detectable Runx3 levels in GIT Ep. Moreover, our analysis of the original Runx3(LacZ/LacZ) mice used in the previously reported study failed to reproduce the GIT expression of Runx3. The lack of evidence for Runx3 expression in normal GIT Ep creates a serious challenge to the published data and undermines the notion that Runx3 is a TS involved in cancer pathogenesis.EMBO Molecular Medicine 10/2011; 3(10):593-604. DOI:10.1002/emmm.201100168 · 8.25 Impact Factor
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ABSTRACT: A major goal of molecular biology is to elucidate the mechanisms underlying cancer development and progression in order to achieve early detection, better diagnosis and staging and novel preventive and therapeutic strategies. We feel that an understanding of Runt-related transcription factor 3 (RUNX3)-regulated biological pathways will directly impact our knowledge of these areas of human carcinogenesis. The RUNX3 transcription factor is a downstream effector of the transforming growth factor-beta (TGF-β) signaling pathway, and has a critical role in the regulation of cell proliferation and cell death by apoptosis, and in angiogenesis, cell adhesion and invasion. We previously identified RUNX3 as a major gastric tumor suppressor by establishing a causal relationship between loss of function and gastric carcinogenesis. More recently, we showed that RUNX3 functions as a bona fide initiator of colonic carcinogenesis by linking the Wnt oncogenic and TGF-β tumor suppressive pathways. Apart from gastric and colorectal cancers, a multitude of epithelial cancers exhibit inactivation of RUNX3, thereby making it a putative tumor suppressor in human neoplasia. This review highlights our current understanding of the molecular mechanisms of RUNX3 inactivation in the context of cancer development and progression.Biochimica et Biophysica Acta 12/2009; 1796(2-1796):315-331. DOI:10.1016/j.bbcan.2009.07.004 · 4.66 Impact Factor
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ABSTRACT: The study of RUNX3 in tumor pathogenesis is a rapidly expanding area of cancer research. Functional inactivation of RUNX3-through mutation, epigenetic silencing, or cytoplasmic mislocalization-is frequently observed in solid tumors of diverse origins. This alone indicates that RUNX3 inactivation is a major risk factor in tumorigenesis and that it occurs early during progression to malignancy. Conversely, RUNX3 has also been described to have an oncogenic function in a subset of tumors. Although the mechanism of how RUNX3 switches from tumor suppressive to oncogenic activity is unclear, this is of clinical relevance with implications for cancer detection and prognosis. Recent developments have significantly contributed to our understanding of the pleiotropic tumor suppressive properties of RUNX3 that regulate major signaling pathways. This review summarizes the important findings that link RUNX3 to tumor suppression.Oncogene 03/2010; 29(18):2605-15. DOI:10.1038/onc.2010.88 · 8.56 Impact Factor