Functional Polymorphism in the MSI1 Gene Promoter Confers a Decreased Risk of Lung Cancer in Chinese by Reducing MSI1 Expression

Transcriptomic signature associated with RNA-binding proteins for survival stratification of laryngeal cancer

RNA-binding proteins (RBPs) have been suggested as important prognostic indicators in different human cancers. This study was designed to search the prognostic value of RBPs of laryngeal squamous cell carcinoma (LSCC). Differentially expressed RBPs (DERBPs) were screened via The Cancer Genome Atlas (TCGA). Bioinformatics methods were used to identify prognostic DERBPs. Expression profiling of training cohort were calculated to develop a transcriptomic signature, which was validated by three independent cohorts (TCGA cohort, GSE65858 cohort and GSE27020 cohort). We identified DERBPs and a set of signatures (GTPBP3, KHDRBS3 and RBM38) were confirmed as prognosis-related hub DERBPs in LSCC, which was also tested and verified by bioinformatics method and molecular biology experiment. The role of immune cell infiltration and drug resistance between subgroups was explored. Furthermore, the risk score based on transcriptomic signature was turned out to be an independent prognostic indicator for LSCC. Finally, a nomogram for further clinical application was established. Our study demonstrated that the transcriptomic signature we constructed could serve as a novel therapeutic target and biomarker for LSCC from the perspective of RBPs.

Circ_0055625 knockdown inhibits tumorigenesis and improves radiosensitivity by regulating miR-338-3p/MSI1 axis in colon cancer

BACKGROUND

Radiotherapy is a main therapeutic method for cancers, including colon cancer. In the current study, we aim to explore the effects of circular RNA (circRNA) circ_0055625 in the progression and radiosensitivity of colon cancer and the underlying mechanism.

METHODS

The expression of circ_0055625 and musashi homolog 1 (MSI1) mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). MSI1 protein expression was determined by Western blot. Cell proliferation was assessed by cell counting kit-8 (CCK-8) and colony formation assays. Cell survival fraction, apoptosis, and invasion were investigated by colony formation assay, flow cytometry analysis, and transwell invasion assay, respectively. Cell migration was detected by wound-healing and transwell migration assays. The binding relationship between microRNA-338-3p (miR-338-3p) and circ_0055625 or MSI1 was predicted by online databases and identified by Dual-Luciferase Reporter Assay. The effects of circ_0055625 silencing on the tumor formation and radiosensitivity of colon cancer in vivo were explored by in vivo tumor formation assay.

RESULTS

Circ_0055625 and MSI1 were upregulated in colon cancer tissues and cells relative to control groups. Radiation treatment apparently increased the expression of circ_0055625 and MSI1 in colon cancer cells. Circ_0055625 knockdown or MSI1 silencing repressed cell proliferation, migration, and invasion and promoted cell apoptosis and radiosensitivity in colon cancer. Also, circ_0055625 silencing-mediated effects were attenuated by MSI1 overexpression. Additionally, circ_0055625 silencing reduced MSI1 expression, which could be attenuated by miR-338-3p inhibitor. Mechanically, circ_0055625 acted as a sponge for miR-338-3p to regulate MSI1. Furthermore, circ_0055625 knockdown hindered tumor growth and improved radiosensitivity in vivo.

CONCLUSION

Circ_0055625 repression inhibited the progression and radioresistance of colon cancer by downregulating MSI1 through sponging miR-338-3p. This result might provide a theoretical basis for improving the therapy of colon cancer with radiation.

LINC01094 Down-Regulates miR-330-3p and Enhances the Expression of MSI1 to Promote the Progression of Glioma

Background

This study aims at probing into the expression, function, and mechanism of LINC01094 and miR-330-3p in glioma.

Materials and Methods

qRT-PCR was employed to examine LINC01094 and miR-330-3p expressions in gliomas. After gain-of-function and loss-of-function models were constructed, CCK-8 and Transwell assays were used to detect the proliferation, migration and invasion of LN229 and U251 cells, respectively. Additionally, dual luciferase reporter gene assay was utilized to verify the binding site between m4iR-330-3p and LINC01094, miR-330-3p, and the 3ʹUTR of musashi RNA binding protein 1 (MSI1). Then, RNA pull-down, RIP, qRT-PCR and Western blot were employed to detect the regulatory relationships among LINC01094, miR-330-3p, and MSI1.

Results

The expression of LINC01094 was elevated in glioma tissues and cell lines, and the high expression of LINC01094 was associated with high grade of glioma. In contrast, miR-330-3p was lowly expressed in glioma tissue. Overexpression of LINC01094 or down-regulation of miR-330-3p promoted the proliferation, migration, and invasion of glioma cells, while LINC01094 knockdown or miR-330-3p up-regulation impeded these processes. miR-330-3p was identified as a target miRNA of LINC01094, and it could be negatively regulated by LINC01094. In addition, miR-330-3p antagonized the function of LINC01094 by negatively regulating MSI1.

Conclusion

LINC01094 promotes the proliferation, migration, and invasion of glioma cells by adsorbing miR-330-3p and up-regulating the expression of MSI1.

[Musashi-1 positively regulates growth and proliferation of hepatoma cells in vitro]

OBJECTIVE

To investigate the regulatory role of Musashi-1 (MSI1) in the proliferation and growth of hepatocellular carcinoma (HCC) cells.

METHODS

We examined the expression of MSI1 in HCC and paired adjacent tissues from 24 patients using immunohistochemistry and Western blotting. A MSI1-expressing vector was constructed and stably transfected into HepG2 cells, and short hairpin RNAs (shRNAs) that targeted MSI1 mRNA were ligated into the vector and stably transfected in Huh7 cells. The effects of MSI1 overexpression and silencing on the proliferation, viability and cell cycle of HepG2 cells were investigated using flow cytometry or MTT assay. The expressions of PCNA, cyclin D1, APC and β-catenin in the HCC cells were detected with Western blotting.

RESULTS

MSI1 expression was significantly up-regulated in HCC tissues as compared with that in the adjacent tissues. Overexpression of MSI1 in HepG2 cells resulted in significantly enhanced cell growth (P < 0.01) and significantly reduced G0/G1 phase cells from (58.42±3.18)% to (40.67±1.22)% and increased S phase cells from (28.51± 1.93)% to (40.06±1.92)% (P < 0.01), causing also increases in the expressions of PCNA and Cyclin D1. Knockdown of MSI1 in Huh7 cells obviously inhibited the cell growth and caused cell cycle arrest at the G1/S phase (P < 0.01) with reduced protein expressions of PCNA and cyclin D1. Overexpression of MSI1 in HepG2 cells also down-regulated the expression of APC and up-regulated the expression of β-catenin protein, while MSI1 knockdown caused reverse changes in Huh7 cells.

CONCLUSIONS

MSI1 promotes the progression of HCC through positive modulation of cell growth and cell cycle via the Wnt/β-catenin pathway.

Knockdown of MSI1 inhibits the proliferation of human oral squamous cell carcinoma by inactivating STAT3 signaling

Musashi RNA-binding protein 1 (MSI1) is highly expressed in several types of cancer; however, its role in oral squamous cell carcinoma (OSCC) remains unknown. The purpose of this study was to investigate the probable mechanism underlying the involvement of MSI1 in OSCC. The results demonstrated that MSI1 was upregulated in OSCC tissues, but not in adjacent healthy tissues. MSI1 silencing resulted in decreased cell proliferative, invasive and migrative capacity. In addition, MSI1 silencing led to cell cycle arrest at the S phase, downregulation of c-Myc and cyclin D1, and upregulation of p21 and p27 levels. Additional studies demonstrated that MSI1 suppression inhibited the activation of signal transducer and activator of transcription 3 (STAT3) signaling. Accordingly, the findings of the present study suggested that MSI1 silencing can suppress OSCC cell proliferation and progression, in part by inhibiting the activation of the c-Myc/STAT3 pathway.