N6-Methyladenosine Reader YTHDF2 Enhances Non-Small-Cell Lung Cancer Cell Proliferation and Metastasis through Mediating circ_SFMBT2 Degradation.

Objective: circ_SFMBT2 was reported to facilitate malignant progression in various cancers, but its function in non-small-cell lung cancer (NSCLC) has not been fully uncovered. This study aimed to investigate the effects of N6-methyladenosine (m6A) methylation of circ_SFMBT2 (circ_0017628) on non-small-cell lung cancer (NSCLC) and its underlying mechanisms. Methods: Paired tumor and noncancerous tissues from NSCLC patients were surgically collected from January 2020 to March 2021 in our hospital. The levels of circ_SFMBT2 and LATS2 in NSCLC and human bronchial epithelial cells were assayed with qRT-PCR. Overexpression or silencing of circ_SFMBT2, LATS2, or YTHDF2 was performed in the NSCLC cells. CCK-8, colony-forming, and transwell assays were performed to analyze cell proliferation, viability, and migration, respectively. Meanwhile, the expression of MMP-9, E-cadherin, vimentin, and the Hippo/YAP pathway components was examined by western blotting. The m6A enrichment in circ_SFMBT2 was verified using methylated RNA immunoprecipitation, and interaction between circ_SFMBT2 and YTHDF2 was assessed by RNA pull-down and immunoprecipitation assays. Results: Both circ_SFMBT2 and LATS2 were lowly expressed in NSCLC cells and tissues. A positive correlation of circ_SFMBT2 with LATS2 was identified, and circ_SFMBT2 was localized predominantly in the cytoplasm. circ_SFMBT2 overexpression negatively regulated cell proliferation, viability, migration, and epithelial-mesenchymal transition while promoting the Hippo/YAP pathway activation. Notably, knockdown of LATS2 effectively abrogated the inhibitory effects of circ_SFMBT2 overexpression on NSCLC cell malignancies. Besides, m6A was specifically enriched in circ_SFMBT2, and circ_SFMBT2 could bind to YTHDF2. Silencing of YTHDF2 led to an increase in circ_SFMBT2 expression while inhibiting the malignancy of cancer cells. Conclusion: Our results showed that YTHDF2 could facilitate NSCLC cell proliferation and metastasis via the Hippo/YAP pathway activation by mediating circ_SFMBT2 degradation.

Galectin-1 secreted by bone marrow-derived mesenchymal stem cells mediates anti-inflammatory responses in acute airway disease.

The hallmarks of allergic airway disease (AAD) include infiltration of inflammatory cells into the bronchoalveolar space. Bone marrow derived mesenchymal stem cells (BMSCs) show anti-inflammatory properties in AAD. In addition, galectin-1 (Gal-1) is a lectin significantly upregulated upon inflammation and is also known to mediate potential anti-inflammatory responses. We hypothesized that BMSCs regulated inflammatory responses by secretion of Gal-1 during AAD pathogenesis. BMSCs were isolated from murine femurs and tibiae and adoptively transferred into an ovalbumin-induced AAD mouse model. Knockdown of Gal-1 in BMSCs was performed using shRNA. Flow cytometry, ELISAs, and immunohistology were performed to analyze inflammatory responses in mice, and a Transwell system was used to establish an in vitro co-culture system of lung epithelial cells (MLE-12) and BMSCs. Administration of BMSCs significantly upregulated Gal-1 expression upon inflammation and decreased infiltration of inflammatory cells and secretion of proinflammatory cytokines in vivo. In addition, we showed that this function was mediated by reduced activation of the MAPK p38 signaling pathway. Similar observations were found using an in vitro lipopolysaccharide-induced model when MLE-12 cells were co-cultured with BMSCs. Gal-1 secretion by BMSCs alleviated inflammatory responses observed in AAD and hence provides a promising therapeutic alternative to AAD patients insensitive to conventional drug treatments.

PARK2 attenuates house dust mite-induced inflammatory reaction, pyroptosis and barrier dysfunction in BEAS-2B cells by ubiquitinating NLRP3.

OBJECTIVE: PARK2, a Parkinson's disease-associated gene, functions as an E3 ubiquitin ligase regulating the degradation of proteins via ubiquitination. Our study was designed to explore its role in allergic asthma and the underlying mechanisms. METHODS: Airway epithelial cell line BEAS-2B was treated with house dust mite (HDM) to mimic allergic asthma in vitro. Lentivirus oePARK2 and siPARK2 were constructed to overexpress and knock down PARK2 expression, respectively. RT-qPCR, western blot, co-immunoprecipitation, and ubiquitination assay were performed to investigate the interaction between PARK2 and NLRP3. NLRP3 inflammasome activity, IL-1ß and IL-18 secretion, pyroptosis, and epithelial barrier integrity were detected to explore the role of PARK2 in allergic asthma. RESULTS: PARK2 expression was remarkably down-regulated in HDM-treated BEAS-2B cells. In BEAS-2B cells, NLRP3 protein was reduced by PARK2 overexpression and increased by PARK2 knockdown. Interestingly, PARK2 overexpression and knockdown didn't affect NLRP3 mRNA. Co-immunoprecipitation assay showed that PARK2 interacted with NLRP3. Proteasome inhibitor MG132 abolished PARK2 overexpression-induced down-regulation of NLRP3 protein. Ubiquitination assays showed that PARK2 overexpression enhanced the ubiquitination of NLRP3. Collectively, PARK2 negatively regulates NLRP3 protein via ubiquitination. In HDM-treated BEAS-2B cells, PARK2 overexpression repressed HDM-induced NLRP3 inflammasome activation, IL-1ß and IL-18 secretion, pyroptosis, and epithelial barrier dysfunction. In BEAS-2B cells, PARK2 knockdown promoted NLRP3 inflammasome activation, IL-1ß and IL-18 secretion, pyroptosis, and barrier impairment, while its effects were abrogated by NLRP3 inhibitor INF39. CONCLUSION: Our study demonstrates that PARK2 attenuates HDM-induced NLRP3 inflammasome activation, the release of inflammatory cytokines, pyroptosis, and barrier impairment in airway epithelial cells by ubiquitinating NLRP3.

Correlation between lung cancer and the HHIP polymorphisms of chronic obstructive pulmonary disease (COPD) in the Chinese Han population.

To further investigate the relationship between lung cancer and hedgehog interacting protein (HHIP) polymorphisms of chronic obstructive pulmonary disease (COPD) patients, we conducted a case-control study in a Chinese Han population. Six HHIP SNPs with minor allele frequencies >5% (rs1489758, rs1489759, rs10519717, rs13131837, rs1492820, and rs7689420) were analyzed in 1,017 COPD patients (767 males and 246 females) and 430 non-COPD patients. Using logistic regression analysis, we found that rs7689420 was significantly associated with lung cancer in COPD patients in the Chinese Han population (P < 0.001). The recessive allele of rs7689420 was associated with the occurrence of lung cancer in all COPD patients (odds ratios [OR] of 0.609 and 0.424 for the CT and TT genotypes, respectively) as well as in serious COPD patients (OR of 0.403 and 0.305 for CT and TT, respectively). Additionally, rs1489759 and rs3131837 were associated with lung cancer in various genetic models. rs1489758, rs1489759, and rs10519717 were also associated with lung cancer in serious COPD patients. However, none of the SNPs were significantly associated with lung cancer in mild COPD patients or healthy subjects. Therefore, the HHIP SNPs of COPD patients likely play a role in lung cancer pathology in the Chinese Han population.

[Detection on drug resistance of Mycobacterium tuberculosis by microscopic observation drug susceptibility].

OBJECTIVE: To evaluate the effects of microscopic observation drug susceptibility (MODS) in detecting susceptibility of Mycobacterium tuberculosis (MTB) onto four first line anti-tuberculosis drugs. METHOD: The 24-hole cell culture plates were used to test drug susceptibility of MTB on liquid medium, and the best detecting condition of MODS assay was probed; 66 clinical isolates susceptibility to streptomycin (S), isoniazid (H), rifampin (R) and ethambutal (E) were evaluated by using MODS assay and Lowenstein-Jensen (L-J), thereafter, all the inconcordance of isolates between MODS and L-J were tested for the minimal inhibitory concentrations (MIC). RESULTS: Concordance rate of the susceptibility to S, H, R and E in 66 clinical isolates detected by MODS and L-J was 97.0%, 90.9%, 95.5% and 86.4% respectively. If the results obtained by L-J were taken as a golden standard, the sensitivity, specificity, positive and negative predictive value (PPV and NPV) as well as accuracy of susceptibility test to S detected by MODS was 96.0%, 97.6%, 96.0%, 97.6% and 97.0%; 100%, 85.4%, 81.0%, 100% and 90.9% to H; 96.2%, 95%, 92.6%, 97.4% and 95.5% to R; 73.7%, 91.5%, 77.8%, 89.6% and 86.4% to E. There were 20 inconsistent results of 16 isolates by comparing MODS with L-J, and MIC yielded 16 results of those 14 isolates showing identical results with those of the MODS, while 4 results of other 4 isolates identical with L-J. CONCLUSION: MODS method simultaneously provides drug susceptibility to S, H, R and E. MODS might be one of the rapid tools to diagnosing multidrug-resistant tuberculosis as it is rapid, simple, inexpensive and has high concordance with L-J drug susceptibility test.