[New early gastric cancer marker PRDX4 promote the tumorigenesis and progression of gastric cancer via eliminating ROS].

Gastric cancer is the fourth most common cancer in the world and the second leading cause of death in cancer worldwide. In order to reduce the mortality rate of gastric cancer, the problem that needs to be solved at present is to find new specific markers of early gastric cancer and increase the detection rate of early gastric cancer, thus fundamentally solving the problem of high mortality of gastric cancer. Previous studies in our laboratory found that Peroxiredoxin 4 (PRDX4) has the potential for early gastric cancer markers. In this study, the role of PRDX4 in transformed cells was studied by establishing a malignant transformation model and transforming cell overexpression, the experiment proves that PRDX4 is responsible for growth and proliferation by reducing the content of reactive oxygen species (ROS) in transformed cells. In the microenvironment, it promotes the malignant transformation of cells, that is, PRDX4 promotes the development of gastric cancer via eliminating ROS.

[Selection of DNA aptamers to cervical intraepithelial neoplasia by SELEX].

An in vitro synthesized random ssDNA library was subjected to 12 rounds of selection against anti-screening cells and sieving cells by SELEX. Normal and inflammatory cervical exfoliation cells were selected as anti-screening cells, and the cervical exfoliation cells of low-grade squamous intraepithelial lesion (CIN1), high-grade squamous intraepithelial lesion (CIN2, CIN3) and cervical carcinoma were selected as sieving cells during the screening process. Then, the highly specific aptamer CIN-Ap4 was established by the analysis of the specificity, affinity and cell immunofluorescence, which can be used as biomarker for Cervical Intraepithelial Neoplasia. Prime Premier 5.0 was applied to design a random ssDNA library. According to the fixed sequence at both ends of the library, a pair of primers were designed and synthesized. At the same time, the optimal annealing temperature, cycle times and primer concentration ratio of PCR procedure were selected. The results under the optimal condition are shown as follows. In the 50 µL reaction system, the optimum reaction conditions of symmetry PCR are as follows: annealing temperature is 49.5 ℃, number of cycles is 15. The optimal reaction conditions of indirect asymmetric PCR are as follows: the primer concentration ratio is 80:1, and the number of cycles is 35. The experiment proves that the oligonucleotide library is constructed successfully, and the highly specific dsDNA and ssDNA can be obtained under optimal PCR conditions with good repeatability, which establishes the foundation for the further exploration and experimentation.