| Platelet-derived factor C(PDGF-C) is a member of the platelet-derived factor(PDGF) family. Only a small amount of PDGF-C express in normal human cells. But PDGF-C expression increased in cancer tissues, and closely related with the proliferation and metastasis of the tumor. Usually, PDGF-C may mediate to make the tumer cells occur many kinds of biological behaviors by binding to its receptor PDGFα or β to fulfill its biological function. Many studies have shown that PDGF-C may promote the formation of new blood vessels, and tumor cell metastasis and proliferation. Many researchers believe that PDGF-C is a kind of cytokines which can activate fibroblast category. In breast cancer, the tumor tissues have a lot of PDGF-C, and its expression level was positively correlated with the degree of malignancy tumors. The PDGF-C receptor PDGFα and β are expressed in the fibroblasts of tumor microenvironment, PDGF- C mediated the activation of fibroblasts, activated by binding to the receptor and activating the receptor, the activation receptor resulting tyrosine kinase pathway activation, involved in the formation and secretion of multiple cytokines in the cellular microenvironment.A growing number of researchers believe that tumor proliferation, metastasis and invasion depends not only on the tumor cells themselves, but also on the growth of its environment. Tumor microenvironment consists of tumor cells, endothelial cells, immune cells, fibroblasts and extracellular matrix. In breast cancer, a large number of activated fibroblasts present in the highly metastatic breast cancer stromal tissue, which also known as cancer-associated fibroblasts(CAFs). CAFs as an important component of the tumor microenvironment, is closely related to the progress of breast cancer, CAFs can secrete a variety of factors mediate breast cancer, development and promotion of breast cancer invasion, proliferation and metastasis. Researchers have widely recognized, such as SDF-1 / CXCR4(stromal cell-derived factor 1 / stromal cell-derived factor receptor 4) biological axis, SDF-1 / CXCR4 is an important factor secreted by CAFs, CAFs through the secretion of SDF-1 / CXCR4 promote tumor directional metastasis and angiogenesis. CAFs also can promote tumor growth and metastasis by secreting other factors, such as hepatocyte growth factor(HGF), epidermal growth factor(EGF), basic fibroblast growth factor(b FGF), insulin-like growth factor(IGF) and so on. CAFs are normal fibroblasts through stimulation of certain cytokines, making activated fibroblasts(CAFs). Therefore, blocking the tumor microenvironment CAFs activation process can block the process of tumor development. PDGF-C binds to the receptor-mediated fibroblast activation, thereby reducing the expression of PDGF-C may also prevent fibroblast activation.The protein of gene sequence encoding express through the process of transcription and translation. Gene expression in human cells is due to the complexity of transcription and translation, so that the human gene expression and regulation systems are also a number of levels is very complex. Where a very important part of the regulation of gene expression is post-transcriptional regulation. One of the most important regulation point of the post-transcriptional is the m RNA stability. Hu R is an RNA binding protein which is the most mature researchs, and distributed in a variety of tissues, including breast, spleen and so on. Hu R activate its function by combining with AU-rich element in m RNA 3’UTR region, to enhance the stability of m RNA. According to the study of the experimental group found a large number of Hu R expressed in highly metastatic breast cancer, while low metastatic breast cancer Hu R expression levels lower, the literature has a similar story. We have found analysis 5 AU-rich elements are present in the 3’UTR region of the PDGF-C m RNA through bioinformatic, which may be Hu R binding sites. Construct the 3’UTR region’s carrier of PDGF-C m RNA, transfected into breast cancer cell line MDA-MB-231 who the Hu R expression is in a high level. Dual luciferase gene reporter systems detected Hu R can significantly increase the expression of luciferase gene, and the second and fourth binding sites of gene expression in the growth of the more obvious. So Hu R can act on 3’UTR region of PDGF-C m RNA and regulate expression of PDGFC. In MDA-MB-231 cells, frist, using si RNA to decrease the expression of Hu R, and then detected the expression of PDGF-C in at different levels of Hu R with the western blot technique. The study found that the use of si RNA reduced the expression of Hu R, expression PDGF-C is also reduced. Description Hu R can modulate the expression of PDGF-C, and for a positive adjustment.Micro RNA(mi R) adjusted the protein expression is also by the Post-transcriptional regulation. mi R is a class of small non-coding RNA molecules that throughout the entire cancer occur,development process, more associated with proto-oncogenes or tumor suppressor genes. mi R generally through binding to a target gene m RNA 3’UTR region, the degradation of m RNA of the target gene, thereby reducing the expression of the target gene encodes a protein. In this study,we found out the possible role of mi R that can act on the 3’UTR region PDGF-C m RNA by bioinformatic analysis. After the adoption of the mir and PDGF-C m RNA 3’UTR of the fluorescence vector co-transfected into MDA-MB-231 cells and cultured for 48 hours. Dual luciferase gene reporter system validation biologically functional mi R, found in analysis software out of the 17 kinds of mi R only mi R-382-5p reduce reading the most obvious. The mi R-382-5p analogs transfected into MDA- MB-231 cells detecting the expression of PDGF-C by western blot, and found that MDA-MB-231 cells were transfected into reducing the expression of PDGF-C after mi R-382-5p analogues. This proves that mi R-382-5p can act on the 3’UTR region of PDGF-C m RNA, degradation of m RNA PDGF-C, so that downregulation of PDGF-C. We detected the expression of mi R-382-5p in two different malignant breast cancer cell line MDA-MB-231 and MCF-7 cells by RT-PCR, showed high metastatic MDA-MB-231 cells, mi R-382- 5p express low, while in the low metastatic MCF-7 cells, the high expression of mi R-382-5p, in line with the previous results of the logic.Both Hu R and mi R-382-5p can act on the 3’UTR regionand of PDGF-C, and simultaneously the presence of breast tumor tissue. The breast cancer cell line MDA-MB-231 cells were divided into three groups, group 1 MDA-MB-231 cells were cultured normal, the second group was given within the cells transfected with mi R-382-5p analogues, group 3 transfected Hu R the si RNA, detection of differential expression of PDGF-C by western blot. The study found that expression levels of PDGF-C is highest in the first group, the second group decreased slightly, and the third group was significantly reduced. Description Hu R and mi R-382-5p available at the post-transcriptional regulation of the expression of PDGF-C, and respectively for positive and negative regulation.In the highly metastatic breast cancer, PDGF-C can be activated fibroblasts in the tumor microenvironment, thereby promoting tumor cell proliferation and metastasis. This study was designed a series of experiments and found that the RNA binding protein Hu R acts on PDGF-C m RNA 3’UTR region, increase the expression of PDGF-C, and mi R-382-5p acts on PDGF-C m RNA 3’UTR region, but decrease the expression of PDGF-C. This research Proliferation provides a new direction of research breast cancer proliferation or transfer adjustment mechanism for us. |
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