Nicotine-induced miR-21-3p promotes chemoresistance in lung cancer by negatively regulating FOXO3a.

Lung cancer is the leading cause of cancer-related mortality worldwide and cigarette smoking is reported to contribute to the lung cancer-related mortality. The present study aimed to investigate the molecular mechanism underlying nicotine-induced chemoresistance in lung cancer. The expression of microRNA (miR)-21-3p and its predicted target FOXO3a in lung cancer cells was detected via reverse transcription-quantitative PCR, in the presence or absence of nicotine. The regulatory effect of miR-21-3p and FOXO3a on lung cancer cell proliferation and apoptosis induced by docetaxel or cisplatin treatment was evaluated by performing Cell Counting Kit-8 and Annexin V/PI staining assays, respectively. The interaction between miR-21-3p and FOXO3a was analyzed by performing luciferase reporter assays and western blotting. FOXO3a overexpression rescue experiments were conducted in vitro and in vivo using a xenograft mouse model to assess the function of miR-21-3p/FOXO3a in lung cancer. Nicotine induced miR-21-3p expression in lung cancer cells in a dose-dependent manner. miR-21-3p downregulated FOXO3a expression by directly binding to the 3'-untranslated region of FOXO3a. Moreover, miR-21-3p knockdown sensitized lung cancer cells to docetaxel or cisplatin treatment. Mechanistically, FOXO3a was predicted as a direct target of miR-21-3p. FOXO3a overexpression promoted the chemosensitivity of lung cancer cells to docetaxel or cisplatin treatment. Furthermore, FOXO3a overexpression antagonized the regulatory function of miR-21-3p on docetaxel- or cisplatin-treated lung cancer cells. In the docetaxel- or cisplatin-treated lung cancer xenograft mouse model, miR-21-3p promoted chemoresistance via negatively regulating FOXO3a. Therefore, the present study demonstrated that nicotine-induced miR-21-3p promoted chemoresistance to docetaxel or cisplatin treatment via negatively regulating FOXO3a, which may serve as a novel therapeutic strategy for the treatment of patients with chemoresistant lung cancer.

STIM1 mediates IAV-induced inflammation of lung epithelial cells by regulating NLRP3 and inflammasome activation via targeting miR-223.

AIMS: Influenza A virus (IAV) infection accelerates the inflammatory injury of lung epithelial cells that contributes to pulmonary lesion. Recently, stromal interaction molecule 1 (STIM1) was found to mediate cellular immune response and participated in lung tumorigenesis. Our study aimed to illustrate the function and mechanism of STIM1 in IAV-induced inflammation injury and oxidative stress of lung epithelial cells. MAIN METHODS: We evaluated the levels of STIM1 in IAV-infected patients' serum and BEAS-2B cells using RT-qPCR, Elisa and western blotting methods. MTT and Elisa were performed to measure cell viability and cytokine contents. Besides, ROS intensity, SOD contents and cell apoptosis were detected based on DCFH-DA probe, colorimetry and cell death kits. A luciferase assay and Pearson's correlation analysis evaluated the associations between target genes. KEY FINDINGS: STIM1 was dramatically up-regulated in IAV-infected patients' serum and BEAS-2B cells. Silencing STIM1 in vitro inhibited oxidative stress and inflammatory responses induced by IAV, and reversed cell viability and suppressed apoptosis. Moreover, miR-223 and NLRP3 were negatively and positively correlated with STIM1. STIM1 was found to regulate NLRP3 expression by binding the AACUGAC motif in miR-223. STIM1/miR-223/NLRP3 axis modulated IAV-induced inflammation injury of lung epithelial cells. SIGNIFICANCE: Our evidence indicated that silencing STIM1 alleviated IAV-induced inflammation injury of lung epithelial cells by inactivating NLRP3 and inflammasome via promoting miR-223 expression. These findings may contribute to understand the mechanism of IAV-induced lung injury and help for therapy of IAV infection.

Significance of Trask protein interactions in brain metastatic cohorts of lung cancers.

A class of adhesion protein that occurs in the membrane with both extracellular and intracellular domain and play vital role in maintaining multicellularity is TRASK, also called CUB-domain containing protein1, CD318 (CDCP1). Specifically, in the current study, documented aggressive grades of lung cancers and distant metastatic tissues were examined for protein interactions of Trask and compared with lung cancer variants in situ. The intracellular domain of Trask has the ability to undergo tyrosine phosphorylation and thereafter undergo increased genomic expression, as well as interact with cytoskeletal proteins in the cell periphery and other local signal transduction machinery to induce invadopodia formation and distant metastasis. We incorporated proximity ligation assay to examine protein interactions of Trask in metastatic lung cancer tissues and compare with advanced and low-grade lung cancers restricted to the primary site of origins. Here, we provide direct evidence that activated Trask, which is a phosphorylated form, binds with cytoskeletal proteins actin and spectrin. These interactions were not seen in locally growing lung cancer and cancer in situ. These interactions may be responsible for invadopodia formation and breaking free from a multicellular environment. Functional studies demonstrated interaction between Trask and the STOCs Orai1 and Stim1. Calcium release from internal stores was highest in metastatic lung cancers, suggesting this mechanism as an initial stimulus for the cells to respond chaotically to external growth factor stimulation, especially in aggressive metastatic variants of lung cancers. Recently, inhibitors of STOCs have been identified, and preclinical evidence may be obtained whether these drugs may be of benefit in preventing the deadly consequences of lung cancer.

[Effect of thymectomy in treatment of myasthenia gravis: analysis of 67 cases].

OBJECTIVE: To evaluate the clinical effects of thymectomy in treatment of myasthenia gravis: (MG). METHODS: The clinical data of 67 patients, 29 males and 38 females, aged 10.5 - 68, who underwent thymectomy were analyzed. RESULTS: According to the Monden's standard the overall effective rate of thymectomy was 71.6%. The remission rate was 32.8% (22/6), the improvement rate was 38.8% (26/67), 14 patients showed no change (20.9%), and deterioration was seen in 5 patients (7.5%). CONCLUSION: An effective method to treat MG, thymectomy should be performed on most of the MG patients early and actively.

[Clinical analysis of operation combined chemotherapy for stage IIIa non-small cell lung cancer].

OBJECTIVE: To study the therapeutic result of operation combined chemotherapy for stage IIIa non-small cell lung cancer. METHODS: From January 2000 to December 2003, the data of 83 cases with stage IIIa non-small cell lung cancer undergoing operation combined chemotherapy and 33 cases with stage IIIa non-small cell lung cancer undergoing non-operative therapy were retrospectively analyzed. The median survival time and the 1-, 2-, 3- year survival rates of the two groups were compared by the Kaplan-Meier method. RESULTS: The median survival time of the operation group was 20.3 months, and the 1-, 2-, 3- year survival rates were 85%, 70%, and 35% respectively. The median survival time of the non-operation group was 14.5 months and the 1-, 2-, 3- year survival rates were 75%, 33%, and 15% respectively. CONCLUSION: The therapeutic result of the operation combined chemotherapy for the stage IIIa non-small cell lung cancer is better than that of the non-operative therapy obviously.