Abstract: Provided is use of an antibody-drug conjugate targeting Her2 in the preparation of a medicine for treating breast cancer patients with liver metastasis or breast cancer patients without lung metastasis. Compared with a control drug group (lapatinib+capecitabine), the application of the antibody-drug conjugate provided in the treatment of breast cancer patients with liver metastasis and in the treatment of breast cancer patients without lung metastasis can significantly improve the survival time of the patients.

Abstract: Mbp_Argonaute proteins from prokaryotes and application thereof are provided. The Mbp_Argonaute protein consists of an amino acid sequence as shown in SEQ ID NO: 1 or a sequence with at least 50% or at least 80% of homology with the amino acid sequence as shown in SEQ ID NO: 1. An Argonaute protein gene derived from a cold-resistant prokaryote Mucilaginibacter paaluis is synthesized and named as MbpAgo, which has binding activity to single-stranded guide DNA and has nuclease activity to target RNA and/or target DNA complementarily paired with the single-stranded guide DNA, the MbpAgo can be used for the target RNA editing in vivo and in vitro to achieve site-specific modification of genetic material. The MbpAgo can modify highly-structured RNAs and not affect an endogenous RNAi pathway of animal and plant cells, provides a new and powerful tool for RNA editing with high cleavage activity and good specificity.

Abstract: An Argonaute protein from eukaryotes and an application thereof are provided. An amino acid sequence of the Argonaute protein is shown in SEQ ID NO: 1 or has at least 50% sequence identity with the sequence shown in SEQ ID NO: 1. The specific cleavage activity of the eukaryotic Argonaute protein on DNA is first proved, and an experimental proof for the study of interaction between the eukaryotic Argonaute protein and DNA is provided. In addition, polypeptides, nucleic acids, expression vectors, compositions, kits, and methods used therein can carry out site-specific operation on intracellular and extracellular genetic materials and can be effectively applied in many fields of biotechnology, providing a new tool for gene editing, modification, and molecular detection of Argonaute polypeptides based on eukaryotic sources.

Abstract: Mbp_Argonaute proteins from prokaryotes and application thereof are provided. The Mbp_Argonaute protein consists of an amino acid sequence as shown in SEQ ID NO:1 or a sequence with at least 50% or at least 80% of homology with the amino acid sequence as shown in SEQ ID NO:1. An Argonaute protein gene derived from a cold-resistant prokaryote Mucilaginibacter paaluis is synthesized and named as MbpAgo, which has binding activity to single-stranded guide DNA and has nuclease activity to target RNA and/or target DNA complementarily paired with the single-stranded guide DNA, the MbpAgo can be used for the target RNA editing in vivo and in vitro to achieve site-specific modification of genetic material. The MbpAgo can modify highly-structured RNAs and not affect an endogenous RNAi pathway of animal and plant cells, provides a new and powerful tool for RNA editing with high cleavage activity and good specificity.