Role of exosomes in metastasis and therapeutic resistance in esophageal cancer.

Esophageal cancer (EC) has a high incidence and mortality rate and is emerging as one of the most common health problems globally. Owing to the lack of sensitive detection methods, uncontrollable rapid metastasis, and pervasive treatment resistance, EC is often diagnosed in advanced stages and is susceptible to local recurrence. Exosomes are important components of intercellular communication and the exosome-mediated crosstalk between the cancer and surrounding cells within the tumor microenvironment plays a crucial role in the metastasis, progression, and therapeutic resistance of EC. Considering the critical role of exosomes in tumor pathogenesis, this review focused on elucidating the impact of exosomes on EC metastasis and therapeutic resistance. Here, we summarized the relevant signaling pathways involved in these processes. In addition, we discussed the potential clinical applications of exosomes for the early diagnosis, prognosis, and treatment of EC.

[Expression and purification of dormancy survival regulator Rv2628 of Mycobacterium tuberculosis and preparation of rabbit anti-Rv2628 polyclonal antibody].

Objective To express and purify the dormancy survival regulator Rv2628 of Mycobacterium tuberculosis, so as to prepare and identify its rabbit polyclonal antibody. Methods Using the genome of Mycobacterium tuberculosis H37Rv strain as a template, the Rv2628 gene was amplified to construct a recombinant expression plasmid which was transformed into an Escherichia coli protein expression strain and induced expression by IPTG. The target protein was purified using Ni-NTA chromatography column, and the rabbit polyclonal antibody was obtained by immunizing New Zealand white rabbits with purified Rv2628 protein. The specificity of polyclonal antibodies was verified by Western blot analysis and indirect ELISA, respectively. Results The PET-30A-RV2628 recombinant carrier was successfully constructed. After induction by IPTG, the RV2628 protein was mainly expressed in the form of inclusion. The high-purity Rv2628 protein was obtained by Ni-NTA column purification. Rabbit anti-Rv2628 polyclonal antibody was obtained after immunizing the rabbit. The antibody had good antigen binding properties and the antibody titer reached 1:1 093 500. Conclusion The high-purity Rv2628 protein and high-titer rabbit anti-Rv2628 polyclonal antibody were successfully prepared.

Hyaluronic Acid-Modified Au-Ag Alloy Nanoparticles for Radiation/Nanozyme/Ag+ Multimodal Synergistically Enhanced Cancer Therapy.

Gold nanoparticles (AuNPs) have been widely documented as tumor radiosensitizers via enhanced energy deposition of ionizing radiation. However, the sensitization efficiency of AuNPs is still far from satisfactory owing to the irradiation on nontarget tissues and the tumor radio-resistance. To address these issues, we report herein the rational design and development of hyaluronic acid-modified Au-Ag alloy nanoparticles (Au-Ag@HA NPs) with effective tumor radiosensitization by receptor mediated tumor targeting as well as microenvironment-activated hydroxyl radicals (•OH) generation. In our work, Au-Ag@HA NPs were synthesized by the coreduction of HAuCl4 and AgNO3 in the presence of trisodium citrate, followed by surface modification of HA to the Au-Ag alloy NPs. HA modification affords the alloy NPs with specific targeting to 4T1 breast cancer cells overexpressing CD44 receptor, while the introduction of Ag atom imparts the alloy NPs with superior multienzyme-like activities to the monometallic AuNPs for efficient tumor catalytic therapy. More importantly, the ionizing radiation and peroxidase-like activity of Au-Ag@HA NPs boost the production of •OH and the release of toxic Ag+ in the tumor sites, thereby leading to effective tumor therapeutic outcome. This work provides a promising treatment paradigm for radiation/nanozyme/Ag+ combined therapy against cancer and will advance the design and development of multifunctional nanoplatforms for synergetically enhanced tumor therapy.