Single-cell Transcriptomes Reveal Characteristics of MicroRNAs in Gene Expression Noise Reduction / 基因组蛋白质组与生物信息学报·英文版

Isogenic cells growing in identical environments show cell-to-cell variations because of the stochasticity in gene expression. High levels of variation or noise can disrupt robust gene expression and result in tremendous consequences for cell behaviors. In this work, we showed evidence from single-cell RNA sequencing data analysis that microRNAs (miRNAs) can reduce gene expression noise at the mRNA level in mouse cells. We identified that the miRNA expression level, number of targets, target pool abundance, and miRNA-target interaction strength are the key features contributing to noise repression. miRNAs tend to work together in cooperative subnetworks to repress target noise synergistically in a cell type-specific manner. By building a physical model of post-transcriptional regulation and observing in synthetic gene circuits, we demonstrated that accelerated degradation with elevated transcriptional activation of the miRNA target provides resistance to extrinsic fluctuations. Together, through the integrated analysis of single-cell RNA and miRNA expression profiles, we demonstrated that miRNAs are important post-transcriptional regulators for reducing gene expression noise and conferring robustness to biological processes.

MiRNA regulatory mechanism in tumor initiation and progression / 中南大学学报(医学版)

MiRNAs can function as oncogenes or tumor suppressor genes. The abnormal expression of miRNAs leads to tumor malignant phenotypes, such as cell proliferation, apoptosis, invasion and metastasis, through which it is involved in the process of tumor initiation, progression and transcriptional regulation network. Therefore, it is important to clarify the mechanism of miRNA involved in the process of tumor initiation and progression. MiRNA regulation mechanism in tumor initiation and progression includes one-to-many and many-to-one regulation between TF-to-miRNA and miRNA-to-target gene, which increases the complexity of miRNA regulation, thus affecting the biological behavior of the tumor, The expression and activity of Drosha and Dicer in the process of miRNA affect the synthesis of mature miRNA and involve in the process of tumor initiation and progression;ceRNA may bind with miRNA by competing with miRNA targeting genes and affect biological function of miRNA as miRNA inhibitor. Therefore the abnormal expression and structure of ceRNA is an important molecular mechanism of tumor initiation and progression. This complicated regulation network comprised by multi-dimensional regulation model and specific regulation of tumor initiation and progression provides impetus to exploring the functional restoration of miRNA as a novel target for cancer diagnosis and therapy.

Study on bio-dynamic equation for gene regulation networks / 第三军医大学学报

Objective To explore a new bio-dynamic differential equation to establish gene regulatory network based on the time-space of gene expression.Methods According to bio-dynamic competitive model and differential equation,a new time-space Lotka-Volterra differential equation was established and was applied to time-order expression data.Results The model was applied to set up the regulation network of yeast genes.The regulatory relation was found and compared with the experiment results.Conclusion The results from the new model were almost consistent with the real situation.So this model can remedy the shortage of other models.It's a new valuable differential equation model.