Generation of a tree shrew breast cancer model using lentivirus expressing PIK3CA-H1047R

DEAR EDITOR,Breast cancer is the most common malignant tumor in women,posing a serious threat to health. Tree shrews(Tupaia belangeri chinensis) are evolutionarily closer to humans than rodents and are emerging as an attractive experimental animal model for breast cancer. The PIK3CA gene is frequently mutated in both human and tree shrew breast tumors. Herein, we effectively overexpressed PIK3CA-H1047R in the mammary epithelial cells of tree shrews using a lentivirus to induce breast tumors.

Tree shrew (Tupaia belangeri)as a novel laboratory disease animal model

The tree shrew （Tupaia belangeri） is a promising laboratory animal that possesses a closer genetic relationship to primates than to rodents. In addition, advantages such as small size, easy breeding, and rapid reproduction make the tree shrew an ideal subject for the study of human disease. Numerous tree shrew disease models have been generated in biological and medical studies in recent years. Here we summarize current tree shrew disease models, including models of infectious diseases, cancers, depressive disorders, drug addiction, myopia, metabolic diseases, and immune-related diseases. With the success of tree shrew transgenic technology, this species will be increasingly used in biological and medical studies in the future.

Breast cancer animal models and applications

Breast cancer is the most common malignancy in women. Basic and translational breast cancer research relies heavily on experimental animal models. Ideally, such models for breast cancer should have commonality with human breast cancer in terms of tumor etiology, biological behavior,pathology, and response to therapeutics. This review introduces current progress in different breast cancer experimental animal models and analyzes their characteristics, advantages, disadvantages, and potential applications. Finally, we propose future research directions for breast cancer animal models.

The big bang of genome editing technology: development and application of the CRISPR/Cas9 system in disease animal models

Targeted genome editing technology has been widely used in biomedical studies. The CRISPR- associated RNA-guided endonuclease Cas9 has become a versatile genome editing tool. The CRISPR/Cas9 system is useful for studying gene function through efficient knock-out, knock-in or chromatin modification of the targeted gene loci in various cell types and organisms. It can be applied in a number of fields, such as genetic breeding, disease treatment and gene functional investigation In this review, we introduce the most recent developments and applications, the challenges, and future directions of Cas9 in generating disease animal model. Derived from the CRISPR adaptive immune system of bacteria, the development trend of Cas9 will inevitably fuel the vital applications from basic research to biotechnology and bio- medicine.

A human-specific insertion promotes cell proliferation and migration by enhancing TBC1D8B expression

Human-specific insertions play important roles in human phenotypes and diseases.Here we reported a 446-bp insertion(Insert-446)in intron 11 of the TBC1D8B gene,located on chromosome X,and traced its origin to a portion of intron 6 of the EBF1 gene on chromosome 5.Interestingly,Insert-446 was present in the human Neanderthal and Denisovans genomes,and was fixed in humans after human-chimpanzee divergence.We have demonstrated that Insert-446 acts as an enhancer through binding transcript factors that promotes a higher expression of human TBC1D8B gene as compared with orthologs in macaques.In addition,over-expression TBC1D8B promoted cell proliferation and migration through“a dual finger”catalytic mechanism(Arg538 and Gln573)in the TBC domain in vitro and knockdown of TBC1D8B attenuated tumorigenesis in vivo.Knockout of Insert-446 prevented cell proliferation and migration in cancer and normal cells.Our results reveal that the human-specific Insert-446 promotes cell proliferation and migration by upregulating the expression of TBC1D8B gene.These findings provide a significant insight into the effects of human-specific insertions on evolution.