OBJECTIVETo investigate the effect of silicon dioxide (SiO₂) on the expression of E-cadherin, α-smooth muscle actin (α-SMA), and transforming growth factor β₁(TGF-β₁) in human pulmonary epithelial cells (A549) with epithelial-mesenchymal transition (EMT), and to study the roles of epidermal growth factor receptor (EGFR) signaling pathway in SiO₂-induced EMT in A549 cells in vitro.

METHODSAlveolar macrophages (AMs) were stimulated with 50 µg/ml SiO₂for 3, 6, 12, 18, 24, or 36 h, and the supernatants were collected to measure the expression of TGF-β₁protein by ELISA. The AM supernatant in which TGF-β₁reached the highest expression (T=18 h) was used as AM-conditioned supernatant. A549 cells were cultured in AM-conditioned supernatant and stimulated with indicated doses of SiO₂(0, 50, 100, and 200 µg/ml) for 48 h. The cell morphological changes were observed using an inverted microscope. The cells were collected at different times, and the mRNA and protein expression levels of E-cadherin, α-SMA, and EGFR were measured by RT-PCR and immunocytofluorescence, respectively.

RESULTSAfter stimulation by SiO₂, the expression level of TGF-β₁protein at each time point was significantly higher in the presence of AM supernatants than in the absence of AM supernatants (P<0.05). With the action time, the expression level of TGF-β₁protein increased at first and then decreased, and the highest level was reached at 18 h. After exposure to SiO₂, A549 cells exhibited mesenchymal characteristics, such as a spindle shape, pseudopodia change, and fibroblast-like morphology, as observed by inverted microscope, especially in the 200 µg/ml group. With increased concentration of SiO₂, the mRNA and protein expression of E-cadherin was down-regulated gradually, especially in the 200 µg/ml group, whereas the mRNA and protein expression of α-SMA and EGFR was up-regulated gradually, especially in the 200 µg/m1 group. There were significant differences between the SiO₂-treated groups (50, 100, and 200 µg/ml SiO₂) and the control group (P<0.05).

CONCLUSIONAfter being stimulated by SiO₂in vitro, AMs have significantly increased expression level of TGF-β₁protein. The AM supernatant together with SiO₂can induce the transition of pulmonary epithelial cells to mesenchymal cells, and its mechanism may be related to the EGFR signaling pathway.

Actins ; metabolism ; Cadherins ; metabolism ; Cell Line, Tumor ; Epithelial Cells ; cytology ; metabolism ; Epithelial-Mesenchymal Transition ; drug effects ; Humans ; Lung ; cytology ; Macrophages, Alveolar ; metabolism ; Receptor, Epidermal Growth Factor ; metabolism ; Signal Transduction ; Silicon Dioxide ; pharmacology ; Transforming Growth Factor beta1 ; metabolism

Objective: To evaluate the efficacy and safety of PEG-rhG-CSF therapy in the primary and secondary prevention of chemo-therapy-induced neutropenia . Methods: This single-center, one-arm, and open-label clinical study involved 217 patients with non-my-eloid malignant tumors. These patients included 18 gynecologic oncology (3 endometrial and 15 ovarian cancer), 50 breast cancer, 30 bone tumor, and 119 lymphoma patients who underwent a total of 774 cycles of chemotherapy, comprising 146 primary and 71 sec-ondary prevention patients. The patients ≥45 kg and those <45 kg received a single subcutaneous injection of 6 mg and 3 mg PEG-rhG-CSF, respectively, 24-48 h after the chemotherapy was completed. All patients received only one dose of PEG-rhG-CSF admin-istration per chemotherapy cycle. Results: The overall incidence of febrile neutropenia (FN) was found to be 5.7%, with rates of 4.9% and 7.2% in the primary and secondary prevention groups, respectively. Univariate and multivariate Logistic regression analyses re-vealed that the longer PEG-rhG-CSF was sustained in the treatment cycle, the lower the incidence of FN was. The incidence of FN was significantly lower in the second cycle of the treatment than in the first in both the primary and secondary prevention groups (cycle 1 vs. cycle 2: 11.6% vs. 4.4%, respectively, P=0.039, in the primary group; 16.9% vs. 5.6%, respectively, P=0.034, in the secondary group). The overall incidence of gradeⅣneutropenia was 10.3% (80/774), with rates of 6.7% (34/510) and 17.4% (46/264) in the primary and secondary prevention groups, respectively (P<0.001). The incidence of gradeⅣneutropenia was significantly lower in the second cy-cle of the treatment than in the first (cycle 1 vs. cycle 2: 17.1% vs. 5.3%, respectively, P=0.004, in the primary group; 46.5% vs. 11.3%, respectively, P<0.001, in the secondary group). The treatment-induced toxicity mainly involved bone pain, with 3.7% (8/217) and 1.8% (4/217) incidence rates for grade 1-2 and 3-4 bone pain, respectively. Conclusions: PEG-rhG-CSF administration can effectively reduce the incidence of FN (5.7%) when prophylactically applied to patients with non-myeloid malignant tumors. Primary prevention can sig- nificantly reduce the risk of grade IV neutropenia in all chemotherapy cycles relative to the secondary prevention.

Objective:To summarize the clinical experience in transoral endoscopic thyroidectomy via sublingual and vestibular approach (TOETSLVA).Methods:We retrospectively reviewed the medical record of patients who underwent TOETSLVA in our department from November 2011 to May 2020, including 3 males and 95 females, aged from 18 to 57 years old. Initial 81 cases were categorized in "Period A (November 2011-November 2015)" and subsequent 17 cases in "Period B (August 2019-May 2020)" . Data about demographics, operation time and complications were collected. SPSS 22.0 software was used for statistical analysis.Results:In Period A, the average age of patients was (34.2±9.4) years old; the mean tumor diameter was (2.33±0.80) cm; postoperative pathology showed benign nodules in 76 cases and malignant carcinoma in 5 cases; there were 65 cases of unilateral subtotal thyroid lobectomy, 6 cases of isthmus lobectomy, and 5 cases of bilateral subtotal thyroid lobectomy, with the mean operation time of (132.70±47.22) min; in 5 cases of unilateral thyroid lobectomy with central lymph node dissection, the mean operation time was (185.4±31.40) min; postoperative neck infections occurred in 6 cases; temporary vocal cord paralysis occurred in 1 case, which it recovered within two months; and CO 2 gas embolism occurred in 2 cases. In Period B, the average age of patients was (35.1±8.5) years old; mean tumor diameter was (1.32±0.67) cm; postoperative pathology indicated malignant nodules in 15 cases and benign nodules in 2 cases; in 2 cases of unilateral thyroid lobectomy, the mean operation time was (153.5±34.64) min; in 15 cases of unilateral thyroid lobectomy with central lymph node dissection, the mean operation time was (123.73±14.26) min; and none of patients developed postoperative neck infections or CO 2 gas embolism. All patients had different degree of cutaneous numbness in the submandibular region after surgery, which recovered within 1-2 weeks. There were no complications such as postoperative secondary hemorrhage, permanent vocal cord paralysis, hypoparathyroidism in both the periods. The median follow-up time was 86 months (57-105 months) in Peroid A and 5 months (3-12 months) in Peroid B. During the follow-up periods, there were no obvious abnormalities in swallowing, chewing, oral sensory function and neck activity, and also no tumor recurrence or metastasis. Conclusions:TOETSLVA is a safe and feasible surgery method, with a good cosmetic result. This approach will not lead to a postoperative cutaneous numbness of the submandibular region for a long time.