Functional Mutations in the microRNA-155 Promoter Modulate its Transcription Efficiency and Expression.

Limited research has been conducted on porcine miR-155 promoters, and previous study from our group have identified two haplotypes (TT and CC) in different pig breeds, each associated with five fully linked mutation sites within or near the miR-155 gene (Li et al. Dev Comp Immunol 39(1):110-116, 2013). In this study, the promoter region of porcine miR-155 was screened, and two important transcription factors, Foxp3 and RelA, were identified. The binding ability of Foxp3 protein was found to be affected by the first mutation site (A/C) using EMSA analysis. In vitro experiments revealed that the expression level of miR-155 was significantly higher in the C haplotype compared to the T haplotype. Additionally, northern blotting assays indicated that both the first mutation site (A/C) and the fourth mutation site (G/T) had a significant impact on miR-155 expression levels. These findings provide further insights into the transcriptional regulation of porcine miR-155 and identify crucial mutation sites that influence miR-155 expression. This knowledge can serve as a basis for identifying potential molecular markers associated with disease resistance in swine.

Research progress of long non-coding RNAs in colorectal cancer / 医学研究生学报

Long non-coding RNAs ( LncRNAs) are a class of RNA transcripts greater than 200 nt in length without the func-tion of protein encoding.LncRNAs, which consist of a great variety of categories and structures, regulate the associated gene expression on multiple levels, including chromatin modification, transcriptional and post-transcriptional regulation, and epigenetic modification. Moreover, LncRNAs are widely involved in the physiological and pathological processes.Recently, a large number of studies have found that the abnormal expression of LncRNAs is closely related to the occurrence, development, invasion and metastasis of tumor, and plays an essential role in pathogensis of colorectal cancer.In this paper, the function of LncRNAs in colorectal cancer is reviewed, which provides a theoretical evidence for its use in the diagnosis and treatment of colorectal cancer in clinical study.

Signal transduction in erythropoiesis induced by total saponins of Panax ginseng / 中国组织工程研究

BACKGROUND: Most of hematopoietic growth factor regulates proliferation and differentiation of blood cells through JAKs-STATs signal transduction pathway. Total saponins of Panax ginseng (TSPG) can promote in vitro differentiation of CD34+ hematopoietic progenitor cells into erythroid cells, with similar effectiveness of hematopoietic growth factor.Erythropoietin receptor (EpoR) expression on the cell membrane of progenitor cells is critical during the erythroid differentiation process.OBJECTIVE: To investigate the molecular mechanism of TSPG to induce erythroid cells through erythropoiesis and its receptor-mediated JAK2/STAT5 signal transduction.DESIGN, TIME AND SETTING: An in vitro cytological observation. The study was performed at the Department of Histology and Embryology, Institute of Basic Medicine, Chongqing Medical University from May 2006 to October 2008.MATERIALS: Umbilical cord blood of normal full-term pregnancy was provided by the First Hospital of Chongqing Medical University. TSPG, purity＞95%, provided by Chongqing Institute of Traditional Chinese Medicine, was diluted in RPMI-1640 for work concentration of 1 g/L and degermed by positive pressure filtration.in RPMI-1640 culture solution containing horse serum, with various dilutions of TSPG (0 as blank control, 10, 25, 50, 75,100 mg/L). The MNCs were cultured on 96-well culture plate, with 0.2 mL in each well. Early erythroid cells were counted on were harvested and cultured separately in RPMI-1640 culture solution containing 10% horse serum as control group and in TSPG (25 mg/L)- conditioned culture system as experimental group. 5 U/mL Epo was added for 0, 2, 5 and 30 minutes.Immunoprecipitation of JAK2/STAT5 was used for the effect of TSPG on Epo/EpoR-induced tyrosine phosphorylation of JAK2/STAT5.MAIN OUTCOME MEASURES: Effect of TSPG on proliferation of erythroid progenitor cells from human umbilical cord blood;Effect of Epo on the proliferation of hematopoietic cells; Effect of TSPG on EpoR expression of the umbilical blood cells; tyrosine phosphorylations of JAK2 and STAT5.RERULTS: TSPG (10-75 mg/L) promoted the colony formation of BEU-E, CFU-E, and the preferential differentiation into erythroid lineage cells was most induced from 25 mg/L of TSPG. Using the colorimetric MTT assay, MNCs exhibited proliferative responses to Epo (2-50 U/mL) reaching maximum at 5 U/mL Epo. The addition of TSPG did not increase the expression of EpoR after MNCs were incubated in the presence of with or without TSPG for 24 hours. The pretreatment with TSPG for 24 hours enhanced Epo-induced tyrosine phosphorylation of JAK2 and STAT5 (STAT5a and STAT5b).