TET2 Is Downregulated in Early Esophageal Squamous Cell Carcinoma and Promotes Esophageal Squamous Cell Malignant Behaviors.

OBJECTIVE: To explore the expression of the ten eleven translocation (TET) 2 protein in early esophageal squamous cell carcinoma (EESCC), precancerous lesions, and cell lines and to evaluate the effect of TET2 on the functional behavior of EC109 esophageal cancer cells. METHODS: Thirty-one samples of EESCC and precancerous lesions collected via endoscopic submucosal dissection at Taihe Hospital, Shiyan, from February 1, 2017, to February 1, 2019, were analyzed. The study involved evaluating TET2 expression levels in lesion tissue and adjacent normal epithelium, correlating these with clinical pathological features. Techniques including 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide, cell scratch assays, flow cytometry for propidium iodide (PI) staining, Hoechst 333258/PI double staining, and nude mouse tumorigenesis experiments were employed to assess the effect of TET2 on the proliferation, migration, cell cycle, apoptosis, and tumorigenic ability of esophageal cancer cells. RESULTS: TET2 expression was notably reduced in early esophageal cancer tissue and correlated with tumor invasion depth (P < 0.05). Overexpression of TET2 enhanced the proliferation and migration of esophageal cancer cells, increased the cell population in the G0 phase, decreased it in the S phase, and intensified cell necrosis (P < 0.05). There was a partial increase in tumorigenic ability (P = 0.087). CONCLUSION: TET2 downregulation in ESCC potentially influences the necrosis, cell cycle, and tumorigenic ability of esophageal cancer cells, suggesting a role in the onset and progression of esophageal cancer.

Clinicopathological features of esophageal schwannomas in mainland China: systematic review of the literature.

OBJECTIVE: Esophageal schwannoma (ES) are rare and mostly benign neurogenic tumors. The clinical misdiagnosis rate of it is high. In this study, the clinicopathologic features of ES in mainland China were studied to better understand the disease and improve the diagnosis and treatment rate. METHODS: A systematic review was conducted in accordance with PRISMA guidelines. The keywords "esophageal schwannoma", "esophageal neurinoma" and "esophageal neurilemoma" were searched for databases such as Pubmed, EMbase, Wanfang Database and Chinese National Knowledge Infrastructure. The search time frame for database was until July 2019. Combined with our patient, the clinicopathological data and the diagnosis and treatment of ES were summarized. RESULTS: ES occurs in the upper part of the mediastinum and in the thoracic esophagus in most patients in the neck, upper and middle segments. CT and PET/CT examinations can be used for diagnosis, but the differentiation value of both benign and malignant ES is similar. The histopathological findings of forceps biopsy specimens are often difficult to diagnose, and deep tissue biopsies may increase pathological accuracy. EUS-FNA is also recommended for ES diagnosis, but it may also be misdiagnosed. Pathological features include a fusiform arrangement in a palisade-like structure or a tumor cell arranged in a network to form a loose structure. ES characteristic immunohistochemistry results showed that S-100 protein has strong immunological activity. CONCLUSION: The definitive diagnosis requires immunohistochemistry, especially immunological reaction with S-100 protein. The appropriate treatment plan should be selected according to the diameter of the lesion. The overall prognosis of ES is good, but attention should be paid to follow-up.

QM and ONIOM studies on thermally activated delayed fluorescence of copper(i) complexes in gas phase, solution, and crystal.

Herein, we have employed B3LYP and TD-B3LYP methods with the QM/MM approach to study the thermally activated delayed fluorescence (TADF) phenomenon of two Cu(i) complexes bearing 5-(2-pyridyl)-tetrazolate (PyrTet) and phosphine (POP) ligands in the gas phase, solution, and crystal form. On the basis of spectroscopic properties, ground- and excited-state geometric and electronic structures, and related radiative and nonradiative rates, we have found that (1) the S1 and T1 excited states have clear metal-to-ligand charge transfer character from the Cu(i) atom to the PyrTet group; (2) the S1 and T1 states have a very small energy gap ΔES1-T1, less than 0.18 eV, which makes the forward and reverse intersystem crossing ISC and rISC processes between the S1 and T1 states very efficient; and (3) the low-frequency vibrational modes related to the torsional motion of the POP and PyrTet groups are found to have significant Huang-Rhys factors and are responsible for the efficient ISC and rISC rates. However, the corresponding Huang-Rhys factors are remarkably suppressed in the crystal compared with those in the gas phase and in solution due to the rigidity of the crystal surroundings; as a result, the ISC and rISC rates are accordingly reduced slightly in the crystal. This comparison also demonstrates that the surrounding effects are very important for modulating the photophysical properties of the Cu(i) complexes. Finally, our work gives helpful insights into the TADF mechanism of the Cu(i) compounds, which could assist in rationally designing TADF materials with excellent performance.

Differentiation potential of bone marrow stromal cells to enteric neurons in vitro.

OBJECTIVE: To investigate whether bone marrow stromal cells (BMSC) can be induced to differentiate into enteric neurons and to produce more nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF). METHODS: Bone marrow stromal cells were harvested from male Sprague-Dawley rats and cultured in Dulbecco's modified eagle medium supplemented with 20% fetal bovine serum. The BMSC were passaged six times and characterized by flow cytometry. The BMSC were pre-induced by basic fibroblast growth factor (10 ng/mL) for 24 h, then induced with GDNF in fetal gut condition medium (FGCM) for 10 days. The expressions of neuronal markers neural specific enolase (NSE), neurofilament (NF), glial cell marker, glial fibrillary acedic protein (GFAP), and enteric neuronal marker protein gene product 9.5 (PGP9.5), neural nitric oxide synthase (nNOS), and enteric neural transmitter vasoactive intestinal polypeptide (VIP) were detected by fluorescent immunohistochemistry. Expression levels of GDNF and NGF mRNA were determined by RT-PCR. RESULTS: The cultured BMSC were CD90 (99.7%) positive and CD45 negative on flow cytometry. At day 10 of induction, 58.5 +/- 10.8% cells adopted neuron-like morphological changes and showed expression of NSE (47.6 +/- 7.5%), NF (75.6 +/- 8.4%), GFAP (negative), PGP9.5 (57.7 +/- 6.5%), nNOS (46.6 +/- 5.4%) and VIP (72.3 +/- 6.7%) by immunofluorescence. The BMSC expressed low levels of NGF and GDNF mRNA; however, after induction of GDNF in FGCM, the expression levels of NGF and GDNF mRNA were significantly increased. CONCLUSION: Bone marrow stromal cells have the potential to be induced to differentiate into enteric neurons, express enteric neural transmitters, and produce more NGF and GDNF. Therefore, BMSC could be used as new method to treat gastrointestinal motility disorders associated with enteric neural lesions.

[Effects of inhibition of cyclooxygenase-2 by RNA interference on proliferation and apoptosis of human gastric cancer cells: an experimental study with human gastric cancer cells and mice].

OBJECTIVE: To study whether the expression level of cyclooxygenase-2 (COX-2) is correlated with the proliferation and apoptosis of cancer cells and to study whether the RNA interference technique can be used in anti-cancer gene therapy. METHODS: WBH1, a eukaryotic expression plasmid of shRNA targeting on COX-2, was constructed. Human gastric cancer cells of the line SGC-7901 were cultured and divided into 3 groups: to be transfected with WBH1 or negative control plasmid HK, or used as un-transfected control group. RT-PCR and Western blotting were used to detect the expression of COX-2 mRNA and protein. MTT method was used to detect the proliferation of the cells. The apoptosis of the cells was determined by flow cytometry. Fifteen nude mice were randomly divided into 3 equal groups: 10 to be inoculated subcutaneously with WBH1 plasmid transfected SGC-7901 cells (inhibition group) or negative control plasmid HK transfected SGC-7901 cells, and 5 were used as un-transfected controls. The mice were observed for 4 weeks to observe the survival and the tumorigenesis. Then the mice were killed to take out the tumors. The tumorigenic rate and tumor inhibition rate were evaluated. RESULTS: The proliferation of the SGC-7091 cells transfected with WHB1 plasmid did not changed significantly 24 and 48 hours after the transfection, however, decreased significantly 96 hours and 1 week after (both P < 0.01). The apoptotic rate of the SGC-7091 cells transfected with WHB1 plasmid was 52.28% +/- 17.91%, significantly higher than that of the cells transfected with the control plasmid HK (0.54% +/- 0.16%) and that of the un-transfected cells (0.52% +/- 0.27%, both P = 0.009) without a significant difference between the latter 2 groups (P = 0.998). Four weeks after inoculation the tumorigenic rate was 100% in both the un-transfected control mice and the mice inoculated with negative plasmid HK transfected SGC-7901 cells. There was no significant difference in tumor size between these 2 groups (P = 0.965). The tumorigenic rate of the mice in the inhibition group was 0.4 with an inhibition rate of 89.8%. The tumor weight of the inhibition group was 0.050 g +/- 0.003 g, significantly lighter than those of the control group and the group inoculated with negative plasmid transfected SGC cells (0.490 g +/- 0.017 g and 0.490 g +/- 0.013 g respectively, both P < 0.01). CONCLUSION: Construction of a eukaryotic expression vector expressing the specific shRNA targeting on COX-2, closely related to the proliferation and apoptosis of tumor cells, and transfection of it into the tumor cells helps inhibit the expression of COX-1, thus inhibiting the growth and proliferation of the tumor cells.