miR-519d-3p Overexpression Inhibits P38 and PI3K/AKT Pathway via Targeting VEGFA to Attenuate the Malignant Biological Behavior of Non-Small Cell Lung Cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a heterogeneous tumor that accounts for approximately 85% of all lung cancer cases worldwide. microRNAs (miRNAs) are believed to play an important role in regulating a variety of biological processes, including immunity and cancer. We investigated the effect of miR-519d-3p on the mitigation of NSCLC in vitro and in vivo. METHODS: RT-PCR or immunohistochemical assays were used to assess the expression of miR-519d-3p. Colony formation, flow cytometry, and transwell assay were respectively used to detect proliferation, apoptosis, and invasion of A549 and NCI-H661 cell lines. Luciferase reporter assay was used to verify targeting the relationship between mir-519d-3p and VEGFA. Western blot was used to examine the expression of Ki67, caspase-3, E-cadherin, N-cadherin, VEGF, P38, and PI3K/AKT. Animal models were established by BABL/c mice to research the effect of mir-519d-3p overexpression in vivo. RESULTS: In vitro, miR-519d-3p overexpression inhibited A549 and NCI-H661 cells proliferation, invasion, and also promoted apoptosis. In addition, miR-519d-3p overexpression downregulated VEGFA expression and decreased the P38 and PI3K/AKT phosphorylation level. In vivo, miR-519d-3p overexpression significantly restrained tumor volume (2087±265 mm3 vs 599±135 mm3, *P< 0.05) and tumor weight (0.45±0.08 g vs 0.13±0.06 g, *P<0.05) compared with the control group. Overexpression of miR-519d-3p downregulated levels of Ki67 and N-cadherin significantly. CONCLUSION: The data indicated that miR-519d-3p could be a novel therapy or adjuvant against NSCLC.

A novel positive feedback loop of linc02042 and c-Myc mediated by YBX1 promotes tumorigenesis and metastasis in esophageal squamous cell carcinoma.

BACKGROUND: Long non-coding RNA (lncRNA) is a class of endogenous RNA with a length of more than 200 nucleotides, which is emerging as a pivotal player in cancer development and progression. However, the functional roles of many members in this class remain largely uncharacterized. In the present study, we explored the biological relevance of linc02042 in esophageal squamous cell carcinoma (ESCC). METHODS: qRT-PCR was used to detect the levels of linc02042 and c-Myc. Western blot was used to assess protein expression level. CCK-8 and Transwell assays were employed to test ESCC cell proliferation and invasion, respectively. The mice study including xenograft tumor and lung metastasis models was used to determine the role of linc02042 in vivo. RNA pull-down, ChIP and luciferase reporter assays were employed to test the relationship between linc02042, YBX1 and c-Myc. RESULTS: Linc02042 was found to be markedly upregulated in ESCC cell lines, tissues and plasma, and was closely correlated with malignant clinical features. Knockdown of linc02042 significantly inhibited ESCC cell viability and invasion in vitro as well as tumor growth and lung metastasis in vivo, whereas overexpression of linc02042 resulted in the opposite results. Mechanistically, linc02042 acted as a scaffold for YBX-1 binding to the 3'-UTR of c-Myc mRNA, leading to enhanced c-Myc mRNA stability, thereby facilitating ESCC growth and metastasis. Moreover, in turn, c-Myc was able to transcriptionally elevate linc02042 by directly binding to the E-box motif proximal to the transcription start site (TSS) of linc02042 promoter. Clinically, linc02042 was identified as an effective diagnostic and prognostic biomarker for ESCC patients, and its expression was strongly positively correlated with c-Myc expression in ESCC tissues. CONCLUSION: Our data suggest that linc02042 plays an important tumor-promoting role in ESCC, which lays a foundation for considering it as a potential target for ESCC patients.

The novel circular RNA circ-CAMK2A enhances lung adenocarcinoma metastasis by regulating the miR-615-5p/fibronectin 1 pathway.

BACKGROUND: Circular RNA (circRNA) has recently been considered as a key regulator in carcinogenesis. In this study, we investigated the functional significance and regulatory role of circ-CAMK2A (hsa_circ_0128332) in lung adenocarcinoma (LUAD). METHODS: GSE101586 was employed to screen differentially expressed circRNAs. = Relative expression levels of circ-CAMK2A, miR-615-5p, fibronectin 1 (FN1), MMP2, and MMP9 were tested by quantitative reverse transcription PCR (qRT-PCR) or western blotting. Functional experiments were performed by CCK-8, wound healing, and transwell assays. Luciferase reporter and biotin-labeled RNA pull-down assays were carried out to evaluate the interaction between circ-CAMK2A, miR-615-5p, and fibronectin 1. In addition, a lung metastasis model was constructed to determine the metastasis-promoting role of circ-CAMK2A in vivo. RESULTS: Circ-CAMK2A overexpression was observed in LUAD and was closely associated with lymph node metastasis, distant metastasis, advanced clinical stage, and poor prognosis. Circ-CAMK2A silencing evidently inhibited LUAD cell migration and invasion, whereas circ-CAMK2A overexpression had an opposite effect. Importantly, overexpression of circ-CAMK2A also enhanced LUAD metastasis in vivo. Mechanistically, miR-615-5p was identified as a direct target of circ-CAMK2A. Circ-CAMK2A up-regulates the expression level of fibronectin 1 by sponging miR-615-5p, thereby increasing MMP2 and MMP9 expression to promote the metastasis of LUAD. CONCLUSION: Circ-CAMK2A plays a crucial role in the metastasis of LUAD, at least partially, by regulating the miR-615-5p/fibronectin 1 axis.

uspA1 of Moraxella catarrhalis clinical isolates in Japan and its relationship with adherence to HEp-2 cells.

The surface protein, UspA1, of Moraxella catarrhalis is involved in adherence to human epithelial cells. We examined the expression of uspA1, and adherence to HEp-2 cells of clinical isolates. The uspA1 gene was detected in 204 of 208 isolates. The 4 uspA1-negative isolates belonged to the 16S rRNA type II with an A to G substitution at nucleotide 445 of 16S rRNA. In 13 isolates of the 16S rRNA type II, transcription of uspA1 was decreased or absent. A relationship between the extent of uspA1 transcription and adherence to HEp-2 cells was found in 5 isolates of the type I. In contrast, the 16S rRNA type II strains still had considerable adherence to HEp-2 cells. The type I uspA1 gene was expressed in Escherichia coli JM109 and the transformants adhered to HEp-2 cells at rates about 7 times higher than the host strain. These data indicated that the uspA1 was virtually ubiquitous in clinical isolates of M. catarrhalis and was responsible for adherence to HEp-2 cells of 16S rRNA type I isolates. However, the data also suggested that adherence of 16S rRNA type II strains to HEp-2 cells was attributed to factor(s) other than UspA1.