ABSTRACT
BACKGROUND: Anoikis resistance has been demonstrated to facilitate distant metastases of cancers. MicroRNA-133b (miR-133b) is found to be down-regulated in various tumors, including esophageal squamous cell carcinoma (ESCC), and closely correlates with the malignant phenotype of ESCC. This study aimed to evaluate the roles of miR-133b in metastases of ESCC via regulating anoikis. METHODS: The expression of miR-133b and related molecules were detected in ESCC tissues and cells. The target relationship between miR-133b and epidermal growth factor receptor (EGFR) was verified by dual luciferase reporter assay. Cell proliferation was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Anoikis and anchorage-independent growth were assessed by anoikis assay and soft agar assay. Migration and invasion were evaluated by scratch and transwell assays. The expressions of related molecules were detected by reverse transcription-quantitative polymerase chain reaction and western blotting. The in vivo results were determined by tumor xenografts in nude mice. RESULTS: MiR-133b level was decreased in ESCC tissues and cells, which negatively correlated with EGFR, integrin ß4 (ITGB4), and phosphorylated focal adhesion kinase levels. Moreover, miR-133b down-regulated EGFR expression in ESCC cells. Overexpression of miR-133b inhibited the anoikis resistance, migration, invasion and epithelial-mesenchymal transition of ESCC cells via targeting EGFR. Finally, miR-133b overexpression suppressed tumor growth and lung metastases of ESCC in vivo. ITGB4/FAK/growth factor receptor-bound protein 2 (Grb2), protein kinase B (AKT), and extracellular signal-regulated kinase (ERK) pathways were involved in the regulatory mechanisms of miR-133b/EGFR axis in ESCC metastases in vitro and in vivo. CONCLUSIONS: The results suggested that miR-133b/EGFR axis regulated metastases of ESCC by affecting anoikis resistance via ITGB4/FAK/Grb2, AKT, and ERK pathways.
ABSTRACT
BACKGROUND: The outbreak of the coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 has been the most important clinical challenge worldwide since January 2020. COVID-19 inactivated vaccines play a crucial role in reducing the rates of morbidity and mortality. CASE SUMMARY: We presented a 48-year-old woman from Haidian District, Beijing, China who developed ischemic colitis after receiving the second dose of COVID-19 inactivated vaccine. Computed tomography of the abdomen showed edema and bowel wall thickening with hypodensity in the sigmoid colon and descending colon. Colonoscopy revealed hyperemia, edema and erosion of the mucosa with superficial ulceration and a yellow-white coating at the descending colon and sigmoid colon. The symptoms were relieved after 1 wk of receiving pinaverium bromide (50 mg, tid) and aspirin enteric-coated tablets (0.1 g, qd). CONCLUSION: The possible occurrence of ischemic colitis should be considered after administration of the COVID-19 inactivated vaccines.
ABSTRACT
BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor entity characterized by early metastasis and late diagnosis. MicroRNA-133b (miR-133b) has been considered as a tumor suppressor in many human cancers by regulating epidermal growth factor receptor (EGFR). However, the specific effects of miR-133b and EGFR on ESCC remain unclear. METHODS: qRT-PCR and western blotting were applied for measuring expression of mRNA and protein. Flow cytometry was used for detecting cell cycle and apoptosis. Cell proliferation, migration and invasion were detected by colony formation and transwell assays. Luciferase reporter assay was used to confirm the interaction between miR-133b and EGFR. RESULTS: Low expression of miR-133b and high expression of EGFR were identified in ESCC cells and tissues. Overexpression of miR-133b or knockdown of EGFR suppressed the cell proliferation, migration, and invasion of ESCC cells, and raised the percentage of G1 phase cells. The apoptosis of ESCC cells were promoted by increasing miR-133b and decreasing EGFR expression. Luciferase reporter assay confirmed EGFR as the target of miR-133b in ESCC cells. Overexpression of miR-133b significantly decreased the phosphorylation of PI3K, ERK and AKT by directly down-regulating EGFR. Higher expression of E-cadherin and CK-18 and lower expression of Vimentin and N-cadherin were observed after the transfection of miR-133b mimics or shEGFR. CONCLUSION: Overexpression of miR-133b could suppress proliferation, migration and invasion of ESCC cells by inhibiting MAPK/ERK and PI3K/AKT signaling pathways through targeting EGFR, indicating that miR-133b might be a potential therapeutic target for the treatment of ESCC.