Objective:To investigate the effect of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in modulat-ing the effects of oral squamous cell carcinoma (OSCC) invasion. Methods:Real-time polymerase chain reaction was employed to de-tect the expression of MALAT1 in samples of OSCC post-radical resection, normal oral mucosa samples, and oral squamous cell lines. MALAT1-siRNA was transfected into TSCCa human tongue squamous cell carcinoma cell lines. Cell proliferation was determined by methyl-thiazolyl-tetrazolium reduction assay. Cell migration and invasive ability were evaluated by scratch test and transwell assay. The expression of proteins that regulated invasion and apoptosis were examined using Western blot assay. Immunofluorescence assay was used to detect changes in epithelial-mesenchymal transition (EMT)-associated proteins in the cells. Tumor-bearing nude mouse models were established by subcutaneous implantation of TSCCa cells. Immunohistochemistry was used to detect up-regulation of proliferating cell nuclear antigen (PCNA) and matrix metalloproteinase-2/9 (MMP-2/9). Results:MALAT1 expression was significantly higher in OSCC than in normal tissues (P<0.05). MALAT1 expression was inhibited by transfecting MALAT1-siRNA. After MALAT1 expres-sion was down-regulated in TSCCa cells, proliferation was inhibited and invasion was attenuated, showing significant differences com-pared with the cells transfected with scrambled siRNA and control cells (P<0.05). Expression of N-cadherin and MMP-2/9 were down-regulated in the cells after MALAT1 was knocked down. Tumor growth was significantly slower in the MALAT1-siRNA group than in the control groups. IHC indicated that PCNA and MMP-2/9 expression of tumor tissues were significantly inhibited in MALAT1-siR-NA group. Conclusion:MALAT1 is over-expressed in human OSCC. MALAT1 reduction can inhibit the proliferation and invasion of OSCC cells. Furthermore, MALAT1 may promote OSCC invasion and metastasis by modulating EMT.

Objective: To investigate the characteristics, diagnosis, primary detection, and prognosis of cervical lymph node metastases of squamous cell carcinoma of unknown primary site (SCCUP). Methods: This study retrospectively analyzed the clinical features and follow-up data of 262 patients with SCCUP. The Chi-square test were used to analyze the clinical performances, characteristics of pri-mary lesions, and sensitivity and specificity of examinations to identify original lesions. Factors related to the overall survival (OS) and progression-free survival (PFS) were also analyzed. Results: The 262 patients with SCCUP comprised more men, with a median age of 57 years. At the follow-up, 70 patients were diagnosed with primary lesions (26.7%), and the detection rates of primary lymph nodes in those who were male (30.1%), with a single lesion site (31%), and with levelⅣdisease (39.3%) were higher than those in patients who were female (17.4%), with multiple lesion sites (18.7%), and with levelⅡ/Ⅲdisease (20.8%). Compared with traditional imaging examinations, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) had higher sensitivity and speci-ficity in detecting the primary tumor. Survival analysis showed that distant metastasis was an independent risk factor affecting OS and PFS, and the effect of N stage on PFS was statistically significant. Conclusions: In SCCUP patients, the proportion of patients who were male, with a single lesion site, and with cervicalⅣlymph node metastasis had higher rates of detection of the primary sites. PET/CT examination is important for the diagnosis of SCCUP, as well as the detection of primary lesions. Advanced N stage and distant metasta-sis indicated poor prognosis.

Background Silica nanoparticles (SiNPs) enter the human body through respiratory tract, digestive tract, and skin, causing body damage. Lung is one of the main damaged organs. Objective To observe the expressions of complement activated fragment C3a and its receptor C3aR in the lungs of mice exposed to SiNPs through respiratory tract, and to explore the involvement of C3a/C3aR in lung injury induced by SiNPs exposure. Methods The ultrastructure of SiNPs (particle size 5-20 nm) was determined under a transmission electron microscope, and the hydrodynamic diameter and surface Zeta potential of SiNPs were determined using a nanoparticle size analyzer. A total of 88 SPF C57BL/6J mice were randomly divided into five groups: a blank control group without any treatment (14 mice), a vehicle control group treated with 50 μL stroke-physiological saline solution by intratracheal instillation (14 mice), and three SiNPs exposure groups (low-dose group, medium-dose group, and high-dose group with 20 mice in each group, who were given 50 μL SiNPs suspension of 7, 21, and 35 mg·kg⁻¹ respectively and exposed once every 3 days for 5 times). The mice were anesthetized on day 1 (1-day model group) and day 15 (15-day model group) after exposure, then sacrificed after extraction of bronchoalveolar lavage fluid (BALF), and lung tissues were retained. The morphological changes of lung tissues were observed by HE staining, the expression level of C3a in BALF was detected by enzyme-linked immunosorbent assay, the deposition of C3a and C3aR in lung tissues were observed by immunohistochemistry, the protein expression level of C3aR was determined by Western blotting, and the localization and semi-quantitative detection of C3a and C3aR in lung tissues was observed by immunofluorescence. Results SiNPs agglomerated in stroke-physiological saline solution. The average hydrodynamic diameter was (185.60±7.39) nm and the absolute value of Zeta potential was (43.33±0.76) mV. The condition of mice in the 1-day model group and the 15-day model group was good, while 2 mice died in the medium-dose group of the 1-day model group due to misoperation. The autopsy results of the two mice showed congestion of the lung tissue, emphysema, and no imperfection of trachea integrity. No death was observed in other dose groups. The HE staining results showed pathological damage to the mouse lung, including alveolar wall thickening and inflammatory cell infiltration after SiNPs exposure. The pathological damage became more serious with the increase of dose. Regarding pathological changes, the 15-day model group was slightly relieved compared with the 1-day model group, but there were still pathological changes. The enzyme-linked immunosorbent assay results showed that there was no difference in the expression level of C3a between the blank control group and the vehicle control group (P＞0.05), the expression levels of C3a in the medium-dose group and the high-dose group were significantly higher than that in the vehicle control group (P<0.05). The immunohistochemistry results showed that C3a deposition was consistent with the enzyme-linked immunosorbent assay results. The Western blotting and the immunohistochemistry results showed that C3aR expression was low in the blank control group and the vehicle control group, while the expression in each dose group tended to increase with the increase of dose. The immunofluorescence results showed that the fluorescence signals of C3a and C3aR were weak in the blank control group and the vehicle control group in the 1-day model group and the 15-day model group, while the fluorescence signals in the lung tissues of mice in the SiNPs exposure groups tended to increase with the increase of dose. Conclusion The increased expressions of C3a and C3aR in complement activation may be related to lung injury induced by intratracheal instillation of SiNPs, suggesting that C3a/C3aR may be involved in lung injury induced by SiNPs exposure.