Imputation method for dropout in single-cell transcriptome data / 生物医学工程学杂志

Single-cell transcriptome sequencing (scRNA-seq) can resolve the expression characteristics of cells in tissues with single-cell precision, enabling researchers to quantify cellular heterogeneity within populations with higher resolution, revealing potentially heterogeneous cell populations and the dynamics of complex tissues. However, the presence of a large number of technical zeros in scRNA-seq data will have an impact on downstream analysis of cell clustering, differential genes, cell annotation, and pseudotime, hindering the discovery of meaningful biological signals. The main idea to solve this problem is to make use of the potential correlation between cells and genes, and to impute the technical zeros through the observed data. Based on this, this paper reviewed the basic methods of imputing technical zeros in the scRNA-seq data and discussed the advantages and disadvantages of the existing methods. Finally, recommendations and perspectives on the use and development of the method were provided.

Biological characteristics and genesis of cancer stem cells / 国际肿瘤学杂志

Cancer stem cells is a small fraction of cells exist in cancers and own the same characteristics of stem cells. It has recently been shown that cancer stem cells in some tumours contain lower reactive oxygen species(ROS) levels and enhanced ROS defence radioresistance. The DNA damage induced by p53 tumor suppressor protein is associated with self cancer stem cells. We have reviewed the biological characteristics including self- renewal, drug resistance, heterogeneity and so on. As to the genesis of the cancer stem cells,some researchers believe that they arise from normal adult stem cells, progenitor cells or mutation of somatic cells, while others consider that cancer stem cells are derived from cell fusion and so on.