REG gamma: a potential marker in breast cancer and effect on cell cycle and proliferation of breast cancer cell

Abstract

To investigate the expression and significance of proteasomes reactivator REG gamma (γ) in breast cancer. First, we showed the expression of REGγ in breast cancer, metastatic lymph nodes and normal breast tissues. Meanwhile, we also analyzed the relationship between REGγ and estrogen receptor (ER), CerBb-2, lymph nodes metastasis and clinical stage of breast cancer. REGγ expression was determined by immunohistochemical staining and western blot. Secondly, we detected the expression of REGγ and REGγ-mRNA in human breast cancer cell lines (MDA-MB-231, MCF-7) and human breast ductal epithelial cell line (HBL-100) by western blot and real-time PCR. Finally, in order to identify effect of REGγ on breast cancer cell cycle and proliferation, we constructed recombinant plasmid of PcDNA3.1-REGγ and designed siRNA for REGγ in vitro. Cell cycle was assayed by flow cytometer (FCM), proliferation was measured by methyl thiazolyl tetrazolium (MTT). The results demonstrated abnormal high expression of REGγ in breast cancer and its metastatic lymph nodes. REGγ expression was related to breast cancer and its status of ER, CerBb-2 and lymph nodes metastasis. REGγ is one of the potential markers in breast cancer. REGγ could facilitate the growth of breast cancer cells.

Expression of Proteasome Activator REGγ in Human Laryngeal Carcinoma and Associations with Tumor Suppressor Proteins

“…Once pass the check point, cell cycle can be accomplished under the driver of cyclins and CDK even though the stimulation from growth factor is absent. It was showed that REGγ could promote HBL-100 cell to go from G1 into S phase (Wang et al, 2009). Therefore, these findings suggest that REGγ overexpression can promote laryngeal cancer cells proliferation and accelerate laryngeal cancer cells growth.…”

“…For instance, REGγ has been reported to be highly expressed in thyroid cancer (Okamura et al, 2003) and in colorectal cancer serum (Roessler et al, 2006). Recently, the overexpressed REGγ has been also found in human breast cancer cells and the metastatic lymph nodes (Wang et al, 2009). On the basis of these observations, we presumed that REGγ may be highly expressed laryngeal cancer and have a role in the development of laryngeal cancer.…”

“…REGγ-deficient mice showed reduced body size and defects in cell-specific mitosis (Murata et al, 1999;Barton et al, 2004). Moreover, the expression of REGγ has been found abnormally high in human breast cancer cells and the metastatic lymph nodes (Wang et al, 2009). Recently, there has study showed that REGγ was a strong candidate for the regulation of cell cycle, proliferation and the invasion in poorly differentiated thyroid carcinoma cells (Zhang et al, 2012).…”

REGγ is critical for skin carcinogenesis by modulating the Wnt/β-catenin pathway

“…It can promote the degradation of multiple proteins including p53 and MDM2 in an ubiquitin-and ATP-independent manner [1][2][3] . Previous studies found that REGg is overexpressed in numerous cancers including breast, thyroid, lung and liver cancers [4][5][6] , suggesting a potential role for REGg in tumorigenesis.…”

Breast Cancer from Molecular Point of View: Pathogenesis and Biomarkers

“…It has been reported that REG could facilitate the growth of breast cancer cells. Abnormal high expression of REG has been observed in breast cancer and its metastatic lymph nodes (60). BCL2 has been introduced as an independent biomarker for prognosis of all types of earlystage breast cancers.…”