CXCL5 inhibits tumor immune of lung cancer via modulating PD1/PD-L1 signaling / 中华肿瘤杂志

Objective: To investigate the role of CXCL5 in tumor immune of lung cancer and to explore the potential molecular mechanisms. Methods: A total of 62 cases of patients with lung cancer admitted in the First Affiliated Hospital of Henan University from May 2018 to December 2019 were recruited as study object. Another 20 cases of patients with pulmonary infectious diseases and 20 cases of healthy control were selected as control. Enzyme-linked immunosorbent assay (ELISA) was used to determine serum levels of CXCL5 in patients with lung cancer, pulmonary infectious diseases and healthy control. Immunohistochemical staining (IHC) was used to detect the expressions of CXCL5 and PD-1/PD-L1 in tumor and paracarcinoma tissues of patients with lung cancer. Pearson correlation analysis was used to evaluate the correlation between CXCL5 and PD-1 in tumor and paracarcinoma tissues of patients with lung cancer. Lewis cells either expressing CXCL5 or vector plasmids were used to establish C57BL/6J mice model of lung cancer, and all mice were then divided into vehicle and PD-1 antibody treatment groups, 10 mice for each group. The mice survival and tumor growth curves were recorded. IHC was used to evaluate the expressions of CXCL5, PD-1 as well as the proportions of CD8(+) T and Treg cells in xenograft tumor tissues. Results: In patients with lung cancer, the serum level of CXCL5 [(351.7±51.5) ng/L] was significant higher than that in patients with pulmonary infectious diseases and healthy control [(124.7±23.4) ng/L, P<0.001]. The expression levels of CXCL5 (0.136±0.034), CXCR2 (0.255±0.050), PD-1 (0.054±0.012) and PD-L1 (0.350±0.084) in tumor were significant higher than those in paracarcinoma normal tissues [(0.074±0.022), (0.112±0.023), (0.041±0.007) and (0.270±0.043) respectively, P<0.001]. CXCL5 was significant positively correlated with PD-1 in tumor tissues of lung cancer (r=0.643, P<0.001), but not correlated with PD-1 in paracarcinoma tissues(r=0.088, P=0.496). The vector control group, CXCL5 overexpression group, vector control + anti-PD-1 antibody treatment group and CXCL5 overexpression + anti-PD-1 antibody treatment group all successfully formed tumors in mice, while CXCL5 overexpression increased the tumor growth significantly (P<0.01), which was abrogated by the treatment of anti-PD-1 antibody. CXCL5 overexpression decreased the mice survival time significantly (P<0.01), this effect was also abrogated by the treatment of anti-PD-1 antibody. The proportion of CD8(+) T cells in CXCL5 overexpression group [(10.40±2.00)%] was significant lower than that in vector control group [(21.20±3.30)%, P=0.002]. The proportion of CD4(+) Foxp3(+) Treg cells in CXCL5 overexpression group [(38.40±3.70)%] was significant higher than that in vector control group [(23.30±2.25)%, P<0.001]. After the treatment of anti-PD-1 antibody, no significant difference were observed for the proportion of CD8(+) T cells [(34.10±5.00)% and (33.40±4.00)% respectively] and Treg cells [(14.70±3.50)% and (14.50±3.30)% respectively] in xenograft tumor tissues between CXCL5 overexpression+ anti-PD-1 antibody treatment group and vector control + anti-PD-1 antibody treatment group (P>0.05). Conclusion: The expressions of CXCL5 and PD-1/PD-L1 are all increased significantly in the tumor tissues of patients with lung cancer, CXCL5 may inhibit tumor immune of lung cancer via modulating PD-1/PD-L1 signaling.

Adriamycin enhances the sonodynamic effect of chlorin e6 against the proliferation of human breast cancer MDA-MB-231 cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of adriamycin (ADM) in enhancing the sonodynamic effect of chlorin e6 against the proliferation of human breast cancer MDA-MB-231 cells in vitro.</p><p><b>METHODS</b>MDA-MB-231 cells were treated with ultrasound/Chlorin e6 alone or in combination with ADM, and the changes in the cell proliferation was determined by MTT assay.</p><p><b>RESULTS</b>Ultrasound (1.0 MHz) at the power intensity of 0.5-2.0 W/cm2 inhibited the proliferation of MDA-MB-231 cells in an intensity-dependent manner, and chlorin-e6 (0.05-1.6 mg/ml) and ADM (0.1-0.4 g/ml) alone both inhibited the proliferation of MDA-MB-231 cells dose-dependently. Compared with ultrasound (0.5 W/cm2, 1.0 MHz, 60 s) or chlorin-e6 (0.05-0.2 mg/ml) alone, a combined treatment with ultrasound and chlorin e6 significantly enhanced the inhibitory effect on the proliferation of MDA-MB-231 cells (P<0.05). ADM significantly enhanced the sonodynamic effect of chlorin e6 (0.1 mg/ml) against the cell proliferation of MDA-MB-231 cells (P<0.05), and the effect was schedule-dependent, which was greater when ADM was added after the sonodynamic treatment (P<0.05).</p><p><b>CONCLUSION</b>ADM can enhance the sonodynamic effect of chlorin e6 against the proliferation of MDA-MB-231 cells in vitro.</p>

Advances in Red Recombination Applied in Knockout of Bacteria Chromosomal Gene / 中国生物工程杂志

Traditional recombination technology of bacteria chromosome and its limitation were introduced. The definition of Red recombination technology is put forward: a method of homologous recombination between foreign linear DNA and the target gene in chromosomes mediated by ? phage Red system. The linear DNA referred here is general PCR product or oligonucleotide, which has a 36~50bp homologous sequence with the target gene in chromosome at both flanking. Red recombination technology leaves out the in vitro DNA restriction enzyme digestion and link process, which makes the knockout and alternation of target gene in bacteria chromosome relatively easier, and becomes an effective method to exploring genes and constructing new strains gradually. The gene inactivation and alternation method aiming at bacteria chromosome applied to Red recombination system was summarized by the structure element, action mechanism, and strategy of recombination, advantage and developing prospect. The Red system includes three genes: bet (aka?), exo and gam (aka ?). Exo is a 5′→3′ exonuclease, which degrades the 5′ ends of linear DNA molecules. Bet is a single-stranded DNA binding protein that binds to the single stranded 3′ ends generated by Exo and promotes annealing to complementary DNA. Gam binds to the host RecBCD complex and inhibits its exonuclease activity. Red recombination system may be constructed in such plasmids as pKD20 and pKD46 or in chromosome of bacteria. Most bacteria are not readily transformable with linear DNA because of the presence of intracellular exonucleases that degrade linear DNA. But when bacteria cells are transformed with pKD20 or pKD46 plasmid, or integrated with a detective ? prophage, Red recombination enzymes may be expressed in host cells, which make linear DNA with 36~50bp extensions that are homologous to both flanking of target genes transform E.coli readily and knock-out or alternate target gene. The Red recombination method is not only useful in chromosomal gene inactivation in E.coli, but also in other bacteria or virus, such as Salmonella, Shigella flexneri and virus HaSNPV. With the proceeding research, Red system will be applied for more and more purposes, and contribute a lot for gene improvement and gene function investigation in the coming Postgenome Era.