MiR-4282 inhibits tumor progression through down-regulation of ZBTB2 by targeting LIN28B in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is the most aggressive type of head and neck cancer with an unsatisfactory 5-year survival rate. MicroRNAs are a group of small noncoding RNAs reported to serve important roles in carcinogenesis, inhibiting certain gene expression via targeting the 3'-untranslated region of messenger RNAs (mRNAs). MiR-4282 has been newly discovered to be a tumor suppressor in colorectal cancer, but it has never been studied in OSCC. The present study aimed to uncover the role of miR-4282 in OSCC. We first confirmed that miR-4282 was downregulated in OSCC and validated its prognostic significance. Through gain-of-function assays, miR-4282 was discovered to inhibit proliferation, migration, and epithelial-to-mesenchymal transition, and induce apoptosis. By mechanistic research, we predicted via bioinformatics tools and confirmed by luciferase reporter and pulldown assays that miR-4282 targeted LIN28B, an RNA-binding protein, which has been reported to regulate RNA stability in cancers. Furthermore, we confirmed the interaction between LIN28B and zinc finger and BTB domain containing 2 (ZBTB2), and validated that miR-4282 regulated mRNA stability of ZBTB2 by inhibiting LIN28B. Rescue assays proved that miR-4282 inhibited tumor progression through LIN28B/ZBTB2 axis. In vivo assays proved that miR-4282 inhibited tumor growth in OSCC. In conclusion, the present study revealed that miR-4282 inhibited tumor progression through downregulation of ZBTB2 by targeting LIN28B in OSCC cells, indicating miR-4282 as a novel biomarker for OSC.

ZNF677 inhibits oral squamous cell carcinoma growth and tumor stemness by regulating FOXO3a.

Oral squamous cell carcinoma (OSCC) is a common cancer with an increasing incidence worldwide. Zinc-finger proteins 677 (ZNF677) is involved in the progression and methylation of various cancers, but its role and mechanism in OSCC remain indeterminate. The expression of ZNF677 was analyzed by online database and immunohistochemistry, while the methylation level of ZNF677 was determined by the methylation-specific PCR. The role and mechanism of ZNF677 in the tumor cell growth, migration, invasion and stemness were addressed by cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) incorporation, Transwell, wound-healing, sphere­formation, and western blot assays. In addition, its function was also investigated in a xenografted mice model. The results showed that ZNF677 was lowly expressed in OSCC with a hypermethylation level, which predicted poor overall survival in patients with HNSC. Upregulation of ZNF677 reduced the cell viability, Edu positive cells, numbers of invasion cells, the migration ability, numbers of spheres formation and the expression of proliferation, migration and stemness related proteins in CAL-27 and SCC25 cells. Mechanically, the relative levels of p-AKT/AKT were decreased and the levels of p-FOXO3a/FOXO3a were increased in both cells overexpressed with ZNF677, which were reversed by the SC79 treatment. Moreover, interference of FOXO3a recovered the suppressive effects of ZNF677 overexpression on cell proliferation, migration, invasion and stemness of OSCC cells. Furthermore, overexpression of ZNF677 reduced the tumor volume and weight, and the relative protein level of p-AKT/AKT with an increased level of p-FOXO3a/FOXO3a, and improved pathological symptoms in vivo. Collectively, ZNF677 suppressed OSCC cells growth, migration, invasion and stemness through inhibiting AKT/FOXO3a pathway.

The influence of lightning activity on NOx and O3 in the Pearl River Delta region.

Extremely high-temperature lightning generates NOx by electrolyzing nitrogen and oxygen molecules, regulating ozone concentration. The Pearl River Delta (PRD) is located in the world's high-value area of lightning density, and lightning-generated NOx (LNOx) cannot be ignored. Using the flash data from Guangdong-Hong Kong-Macao Lightning Location System and multi-site atmospheric composition data, we estimate the NOx variations in lightning activity and its impact on O3 across the PRD region. The cloud-to-groud (CG) frequency from 2013 to 2021 shows a decreasing trend driven by urban regions. We observe that the lightning density is steadily decreasing from the south-central part of Guangzhou City to the surrounding area. A comparison of the different sites with lightning days and non-lightning days shows that a significant amount (13. 84-20. 47 %) of ground-level NOx concentration at urban stations can be attributed to lightning NOx emissions. A lower lightning frequency and low background concentration observed at suburban sites indicated a limited contribution of LNOx. The average decrease in O3 concentration at urban stations (15.92-25.06 %) was significantly higher than that at suburban stations (5.34-8.95 %) due to the influence of titration and lower actinic radiation. There was a greater fluctuation in NOx and O3 concentrations during the cases, and the surface NOx concentration displayed the most significant responsiveness to LNOx under direct lightning striking in the tall tower. This phenomenon has not been reported, however, it is consistent with the laboratory-based observations suggesting the amount of LNO increases with peak current. LNOx significantly impacts air quality in the PRD during the high convective season. Further in situ and vertical distribution observations are necessary to explore the ground-level impact of LNOx.

Comparison of three surgical models of bone tissue defects in cleft palate in rabbits.

OBJECTIVE: Cleft palate is one of the most common craniofacial birth defects in the maxillofacial region. There is an urgent need in tissue regeneration research to establish animal models that faithfully mimic human diseases. Here, we compared three surgical models of bone tissue defects in cleft palate in rabbits in order to screen for the biomaterials that induced optimal bone regeneration. DESIGN: Rabbits were used to establish the models of hard palate cleft, alveolar cleft, and alveolar process cleft. Eight weeks following surgery, bone tissue self-healing capacity was estimated by macroscopic appearance and calculating the area of defective bone tissue. The dimensions of the upper jaw in left and right sides were measured at zero and eight weeks. RESULTS: Bone defects in three types of cleft palate models were made at the positions of the hard palate, alveoli and alveolar process. After 8 weeks, when the hard palate was partially excised, it underwent self-healing. When the hard palate was completely excised, it underwent partial self-healing. However, in the models of alveolar cleft and alveolar process cleft, there was no significant self-healing in the bone tissues. The dimensions of the upper jaw in left and right sides were no significant differences in three types of cleft palate models. CONCLUSIONS: Bone defects in the alveolar and alveolar process clefts exhibit a diminished capability for self-healing. This study may provide valuable information for the screening of materials that induce bone regeneration.

Liver epithelioid progenitor cells derived from fetal Luxi bovine alleviate liver fibrosis.

Liver epithelioid progenitor cells (LEPCs) have important roles in liver therapy because of their hepatic differentiation potency in vitro and in vivo. Despite many researches on humans, mice, and rats, equivalent progenitor cells derived from bovine are relatively rare. The purpose of our current study is to characterize bovine LEPCs, and research on the cure potency of this heteroplastic progenitor cells on mice liver fibrosis. We have used collagenase IV digesting and differential adhesion method to isolate slabstone shape, EpCAM, LGR5, NCAM1 and SOX9 positive progenitor cells from fetal Luxi bovine liver. When cultured in hepatic differentiation media containing 20 ng/ml Oncostatin M, LEPCs can differentiate into hepatocytes in vitro. After 4 weeks of intravenous tail vein injection into CCl4-injured mouse liver, LEPCs engrafted into liver parenchyma, differentiated into ALB positive hepatocytes, and could alleviate liver fibrosis through down regulating fibrosis genes-Tgfb1 and α-SMA as well as decreasing expression of collagen gene Col1a1, Col3a1, and Col4a1, and regain liver function by recovering ALT and AST. Our findings provided a useful tool for studying liver development in vitro, new cell resource for heterograft on mouse liver diseases, and a new platform for researches on immune rejection of heterogeneous cell transplantation.

Leaching zinc from spent catalyst: process optimization using response surface methodology.

The spent catalyst from vinyl acetate synthesis contains large quantity of zinc. The present study attempts to leach zinc using a mixture of ammonia, ammonium carbonate and water solution, after microwave treatment. The effect of important parameters such as leaching time, liquid/solid ratio and the ammonia concentration was investigated and the process conditions were optimized using surface response methodology (RSM) based on central composite design (CCD). The optimum condition for leaching of zinc from spent catalyst was identified to be a leaching time of 2.50 h, a liquid/solid ratio of 6 and ammonia concentration 5.37 mol/L. A maximum of 97% of zinc was recovered under the optimum experimental conditions. The proposed model equation using RSM has shown good agreement with the experimental data, with a correlation coefficient (R(2)) of 0.95. The samples were characterized before and after leaching using X-ray diffraction (XRD), nitrogen adsorption and scanning electron microscope (SEM).