Anti-tumor activity of tigecycline: a review / 生物工程学报

Tigecycline is a novel glycylcycline antibacterial drug, which shows both antibiotic function and anti-tumor activity. This review summarizes the single and combined use of tigecycline for tumor treatment and the underpinning mechanisms. As an inhibitor for mitochondrial DNA translation, tigecycline affects the proliferation, migration, and invasion of tumor cells mainly through inhibiting mitochondrial protein synthesis and inducing mitochondrial dysfunction. Although the effect of tigecycline monotherapy is controversial, the efficacy of combined use of tigecycline is satisfactory. Therefore, it is important to explore the molecular mechanisms underpinning the anti-tumor activity of tigecycline, with the aim to use it as a cheap and effective new anti-tumor drug.

Functionalized genetic engineered silk-based biomaterials and their applications / 生物工程学报

Silk-based biomaterials are featured with excellent mechanical properties, good biocompatibility and biodegradability, which contribute to their potential applications in biomedical field. The current recognition of silk protein materials in structure and function provides a basic theory for the transformation of silk protein into new types of biomaterials. In addition, exogenous sequences encoding new peptide or structural domain can be inserted into the maternal gene sequences encoding silk proteins through genetic engineering technology to synthesize novel silk-based biomaterials with unique functions. This review summarizes the current trend and development perspective of genetically engineered functional silk-based materials for biomedical applications.

Progress in roles and mechanisms of deacetylase SIRT7 / 生物工程学报

As a member of the Sirtuins family in mammals, SIRT7 locates in nucleus and is a highly specific H3K18Ac (acetylated lysine 18 of histone H3) deacetylase. Recent studies showed that SIRT7 could participate in the ribosomal RNA transcription, cell metabolism, cell stress and DNA damage repair through various signaling pathways. In addition, SIRT7 is also closely related with aging, heart disease and fatty liver. In particular, SIRT7 plays important roles in the regulation of initiation and development of various tumors, such as liver cancer, gastric cancer, breast cancer, bladder cancer, colorectal cancer, and head/neck squamous cell carcinoma. This review describes the cellular and molecular functions of SIRT7, and systematically summarizes recent progress of SIRT7 in human disease.

Advances in mesenchymal to epithelial transition factor signaling pathway and inhibitors / 生物工程学报

As a receptor tyrosine kinase, mesenchymal to epithelial transition factor (MET) is the membrane receptor for hepatocyte growth factor (HGF), which is related with a series of biological functions, such as cell proliferation, progression, apoptosis, metastasis and morphological changes. As research continues, MET is amplified or overexpressed in a wide range of human cancers and closely related with worse prognosis. Therefore, various MET inhibitors are currently being developed as potential treatments for a variety of cancers. Based on our current study we summarize the existing knowledge on structure, biological function and its inhibitors of MET and provide a data phase for future researchers.

Roles and mechanisms of netrins in cancer development / 生物工程学报

As secreted protein and membrane-bound proteins, netrins play important roles in biological processes such as neural cell migration, differentiation and apoptosis. Netrins were thought to guide axon outgrowth and central nervous system morphology since they were discovered. Besides, they also participate in physiological processes such as cell adhesion, migration, differentiation, angiogenesis, lymph angiogenesis, and inflammation in non-neural tissues. Recent studies showed that netrins also involved in the regulation of initiation and development of various tumors including colorectal cancer, pancreatic ductal adenocarcinoma. Because of the functional diversity of netrins and the different biological effects of different receptors in tumor tissue, the specific mechanism of their action in tumors remains unclear. Based on current research progress of our group, this review summed up recent research findings on netrins in relation to cancer biology, suggested possible mechanisms, and discussed the implications in cancer research and intervention.

Structure and function of BmIntegrin β2 in silkworm, Bombyx mori / 生物工程学报

Integrins are cell adhesion receptors, which consists of several transmembrane glycoproteins. They are widely distributed on the cell surface and involved in signal transduction pathways. As a heterodimer, each integrin is composed of one α subunit and one β subunit. Integrins are mainly expressed on lepidopteran hemocytes and involved in cell immune response. The full-length cDNA sequence of BmIntegrin β2 was obtained by PCR and RACE, including 2 434 bp. BmIntegrin β2 was predicted to be a transmembrane protein. The BmIntegrin β2 expression profile was detected by qRT-PCR at L4D3 or L5D3 larval stage, and it was highly expressed in hemocyte and hematopoietic organ. Anti-BmIntegrin β2 polyclonal antibody was generated following prokaryotic expression, protein purification and animal immunization, which is highly specific and effective for recognizing BmIntegrin β2 protein through Western blotting. The results of plasmatocytes adhesion experiment showed that BmIntegrin β2 plays an important role on the adhesion and spreading of plasmatocytes to foreign surfaces. This study provides a foundation for further research of the biological function of BmIntegrin β2 gene.

Cloning and expression of Bmintegrin β1 in silkworm Bombyx mori / 生物工程学报

Integrins are transmembrane glycoproteins, closely related to many physiological and pathological processes. In order to explore its role in silkworm, by PCR and Rapid-amplification of cDNA ends (RACE) technology, the full-length cDNA of Bmintegrin β1 in silkworm was acquired. The domain was predicted by domain prediction website. Phylogenetic tree was constructed to analyze its evolutionary relationship. By prokaryotic expression system, protein purification method and immunizing mouse, the antibody against Bmintegrin β1 recombinant protein was obtained. The spatial-temporal expression profile of Bmintegrin β1 was investigated by semi quantitative PCR and Western blotting. Then we identified all 3 different spliceosomes, and they shared a common open reading frame of 2 502 bp, encoding 833 amino acids. Bmintegrin β1 contained all the classic domains of the integrin family, such as Integrin-B-tail, transmembrane domain etc. Phylogenetic analysis indicated that Bmintegrin β1 was close to the homologous proteins from Heliothis assulta and Danaus plexippus. In order to understand the function of Bmintegrin β1 further, we generated the antibody. In addition, Western blotting demonstrated that the antibody recognized the Bmintegrin β1 recombinant protein. Then, semi quantitative PCR and Western blotting results showed that Bmintegrin β1 was widely expressed in most of tissues, among of them, it's exhibited the highest expression level in hemacyte. Overall, this study provides a foundation for the study of silkworm integrin family.

Cloning and characterization of BmBrat in silkworm, Bombyx mori / 生物工程学报

NHL proteins, which play important roles in regulation of cell proliferation and differentiation, have been extensively studied on mammals. Here, we cloned a member of NHL protein family namely BmBrat in silkworm. The full-length cDNA sequence of BmB rat was obtained by means of the rapid amplification of cDNA ends (RACE), including 3 614 bp. The ORF is 2 580 bp long, encoding a protein with 859 amino acid residues. The molecular weight is 94.3 kDa and the isoeledtric point (pI) is 6.65. The BmBrat expression profile was detected by RT-PCR at L5D3 larval stage, and it was expressed in all tissues, including silk gland, midgut, fat body and malpighian tubule. However, it was highly expressed in ovary and head. The expression profile was also detected at different stage of embryo development, and reached a peak at the 4th and 5th days of the embryonic period. Anti-BmBrat polyclonal antibody was generated f6llowing prokaryotic expression, protein purification and mice immunization, which is highly specific and effective for recognizing BmBrat protein through Western blotting and immunofluorescence staining. Subcellular localization of BmBrat in hemocytes revealed that it was specifically expressed in cytoplasm. This study provides a foundation for further research of the biological function of BmBrat gene.

Cloning and expression of scavenger receptor class B BmSCRB8 in silkworm Bombyx mori / 生物工程学报

Scavenger receptor class B is involved in various indispensable physiological processes, like the formation and inhibition of atherosclerosis or other cardiovascular diseases, innate immune defense and the removal of apoptotic cells. Here, we cloned BmSCRB8, a member of scavenger receptor class B in silkworm. We obtained the full-length cDNA sequence of BmSCRB8 by rapid amplification of cDNA ends (RACE), including 2 668 bp. The ORF of BmSCRB8 is 1 704 bp, encoding 567 amino acids. Online software prediction indicated that the molecular weight of BmSCRB8 is 63.87 kDa and the isoelectric point (pI) is 6.06. The space-time expression profile of BmSCRB8 was detected by reverse transcription PCR (RT-PCR), which implicated that BmSCRB8 is extensively expressed in each tissue and at each stage of blood. In addition, BmSCRB8 is highest expressed in fat body of silkworm, and is highly expressed in metamorphosis periods. Anti-BmSCRB8 polyclonal antibody was generated through prokaryotic expression, protein purification and mice immunization. Simultaneously, we constructed BmSCRB8 eukaryotic vector and then transfected embryonic cell line of silkworm. Immunofluorescence and overexpression showed that BmSCRB8 expressed specifically in membrane. Western blotting demonstrated that BmSCRB8 protein can be specifically recognized by anti-serum generated after mice immunization.

Identification and characterization of a novel hemocyte specific gene Bm04862 in silkworm, Bombyx mori / 生物工程学报

Bm04862 is a novel hemocyte-specific gene, which has been identified and cloned through the microarray data in silkworm, Bombyx mori. Initially, we successfully obtained the full-length cDNA sequence of Bm04862 via the rapid amplification of cDNA ends (RACE). The sequence consists of an open reading frame (ORF) with 819 bp, which could encode 273 amino acid residues. The bioinformatics analysis predicted that Bm04862 was a transmembrane protein. Furthermore, qRT-PCR analysis revealed that the expression of Bm04862 was specifically detected in hemocyte and reached a peak at L4M and PP2 stage. Bm04862 was overexpressed in Sf9 insect cells, and the cellular localization indicated that Bm04862 was specifically located in cytoplasm and nuclei membrane. Interestingly, the expression of Bm04862 increas'd dramatically after challenged with Escherichia coli for 24 hours, which predicted its potential role in the innate immune system. Overall, this study could provide the fundamental knowledge for further research.

Function of SIRT6 in tumor initiation and progression / 生物工程学报

As a member of the sirtuins family, also called Class III histone deacetylases (HDACs), SIRT6 has many catalytic enzyme activities and plays a pivotal role in biological processes including anti-aging, chromatin regulation, transcriptional control, glucose and lipid metabolism, and DNA damage repair. Recently, increasing evidences indicated that SIRT6 was related to initiation and development of tumors, such as hepatic cancer, lung cancer, breast cancer and genital system tumors. However, SIRT6 might play a dual role in tumorigenesis and progression. SIRT6 often acted as a tumor suppressor, but might play an oncogenic role. Based on our current study, we depicted the essential roles of SIRT6 in the initiation and progression of various tumors, and summarized its mode of actions, which might provide clues for cancer therapy.

Essential role of mitochondria in tumorigenesis / 生物工程学报

Tumorigenesis is a complex process that is regulated by a variety of network signals. With the continuous development of the process, tumor cells gradually exhibit lots of hallmarks.Tumor cells have the characteristics of unlimited proliferation, resistance to apoptosis, evading immune surveillance, among others. As a unique organelles, mitochondria play an important role in cellular energy metabolism, reactive oxygen species producing and apoptosis process. Particularly, mitochondria have a close relationship with tumor development. In this review, we focus on the essential role of mitochondria in tumor cells development.