Downregulation of miR-552 in hepatocellular carcinoma inhibits cell migration and invasion, and promotes cell apoptosis via RUNX3

LINC00261 Inhibits Esophageal Cancer Radioresistance by Down-Regulating microRNA-552-3p and Promoting DIRAS1

OBJECTIVE

Esophageal cancer (EC) represents a life-threatening tumor with an ever-increasing incidence rate. Long intergenic non-protein coding RNAs (LINCs) have also become a topic of interest in EC. In a similar light, the current study aimed to investigate the role of LINC00261 in EC radioresistance.

METHODS

Firstly, radioresistant EC cell lines TE-1-R and TE-5-R were established using TE-1 and TE-5 cells. Subsequently, LINC00261, microRNA (miR)-552-3p, and DIRAS1 expression patterns in EC tissues and adjacent normal tissues and EC cells were evaluated. In addition, survival fraction (SF), colony formation, apoptosis, and γ-H2AX levels were analyzed, followed by the detection of the binding relation between LINC00261 and miR-552-3p and between miR-552-3p and DIRAS1. Lastly, xenograft transplantation was carried out to confirm the effects of LINC00261 on EC radioresistance in vivo.

RESULTS

LINC00261 and DIRAS1 were poorly-expressed in EC tissues and cells, but miR-552-3p was over-expressed. In EC cells with X-ray radiation, over-expression of LINC00261 reduced SF and cell viability, strengthened γ-H2AX levels, and promoted apoptosis, while all these trends were counteracted by miR-522-3p over-expression or DIRAS1 silencing. Mechanistic investigation further validated the binding relation between LINC00261 and miR-552-3p, and between miR-552-3p and DIRAS1. Moreover, LINC00261 over-expression suppressed tumor growth and reduced EC radioresistance in vivo.

CONCLUSION

Altogether, our findings indicated that LINC00261 exerts a suppressive effect on EC radioresistance via the competing endogenous RNA network to sponge miR-552-3p and up-regulate DIRAS1 transcription.

miR-552 promotes the proliferation and metastasis of cervical cancer cells through targeting MUC15 pathway

Accumulating evidence shows that microRNAs (miRNAs) play key roles in tumorigenesis, progression, recurrence and drug resistance of malignant tumors. The tumor-promoting role of miR-552 has been evidenced in multiple tumors. Yet, the relevance of miR-552 in cervical cancer remains undetermined. This study aimed to investigate the role of miR-552 in cervical cancer proliferation and metastasis. Herein, we for first found that miR-552 expression was upregulated in cervical cancer tissues compared with their normal controls. Functional assays revealed that miR-552 promoted the proliferation and metastasis of cervical cancer cells. Mechanically, bioinformatics and luciferase reporter analysis identified MUC15 as a direct target of miR-552. Reduced MUC15 expression was detected in cervical cancer, and MUC15 overexpression exhibited a tumor-suppressive effect. MUC15 restoration partially abolished the discrepancy of growth and metastasis capacity between miR-552 overexpression cervical cancer cells and control cells. Taken together, these data demonstrate that miR-552 acts as a potential oncogene miRNA in cervical cancer, which exerts its function through targeting MUC15.

miR-552: an important post-transcriptional regulator that affects human cancer

MiR-552 is a small non-coding RNA located on chromosome 1p34.3, and its expression level is significantly up-regulated in tissues or cells of various tumors. miR-552 can target multiple genes. These targeted genes play important regulatory roles in biological processes such as gene transcription and translation, cell cycle progression, cell proliferation, apoptosis, cell migration, and invasion. Besides, miR-552 may affect the efficacy of various anticancer drugs by targeting genes such as TP53 and RUNX3. This review summarizes the biological functions and clinical expressions of miR-552 in human cancer. Our goal is to explore the potential value of miR-552 in the diagnosis, prognosis, and treatment of human cancer.

LncRNA TTN-AS1 Regulates miR-524-5p and RRM2 to Promote Breast Cancer Progression

Background

Recent studies suggest many long non-coding RNAs (lncRNAs) are crucial oncogenes or tumor suppressors. This study intended to investigate the biological function and mechanism of lncRNA TTN antisense RNA 1 (TTN-AS1) in the progression of breast cancer (BC).

Materials and Methods

BC tissue samples were collected. The expression of TTN-AS1 in BC tissues and adjacent tissues was detected by qRT-PCR, and the relationship between pathological indicators and TTN-AS1 expression was analyzed by chi-square test. BC cell lines T47D and BT549 were utilized as cell models. CCK-8 assay and BrdU assay were used to detect the effect of TTN-AS1 on BC cell proliferation. Transwell assay was used to detect the effects of TTN-AS1 on cell migration and invasion. In addition, dual-luciferase reporter gene assay was used to confirm the targeting relationship between miR-524-5p and TTN-AS1. Western blot was used to detect the function of TTN-AS1 on regulating ribonucleotide reductase subunit 2 (RRM2) and survivin. Additionally, subcutaneous xenotransplanted tumor model and tail vein injection model were constructed in vivo.

Results

The expression of TTN-AS1 in BC tissues was significantly higher than that in normal tissues, and its high expression was correlated with adverse pathological indicators. Overexpression of TTN-AS1 significantly promoted the proliferation, migration and invasion of BC cells. TTN-AS1 knockdown suppressed the malignant phenotypes of BC cells. TTN-AS1 overexpression significantly impeded the expression of miR-524-5p, but increased the expression of RRM2.

Conclusion

TTN-AS1 exerts oncogenic function in BC by repressing miR-524-5p and increasing the expression of RRM2.

Tripterine Restrains the Aggressiveness of Hepatocellular Carcinoma Cell via Regulating miRNA-532-5p/CXCL2 Axis

Introduction

Triterpene has attracted considerable interests because it exhibits anticancer effects. However, the effects of tripterine on hepatocellular carcinoma (HCC) are not well studied. In the current study, the mechanism of tripterine on HCC cells growth and metastasis was examined.

Methods

The inhibitory effect on the growth and aggressiveness in HCC cells was analyzed by Cell Counting Kit-8 (CCK-8), wound healing and Transwell assay. The levels of microRNA-532-5p (miR-532-5p) in HCC cells and tissues were measured using qRT-PCR. The expression of chemokine (C-X-C Motif) ligand 2 (CXCL2) was determined by Western blotting and immunohistochemistry (IHC). Luciferase reporter gene assay was used to validate the binding between miR-532-5p and CXCL2. The impact of tripterine on the growth and metastasis of HCC cells in vivo was analyzed using transplanted tumor model and experimental lung metastasis model, respectively.

Results

We found that tripterine inhibited HCC cells proliferation, migration ability and invasion. Under tripterine treatment, the level of miR-532-5p was strikingly raised, and overexpression of miR‑532-5p reduced cell viability and metastatic-related traits. In addition, we identified CXCL2 as a target of miR-532-5p in HCC. Rescue experiments indicated that overexpression of CXCL2 restored the migration and invasive capacity of HCC cells inhibited by miR-532-5p or tripterine treatment. Finally, the tumor growth and metastatic ability of HCC MHCC97H cell in vivo were also significantly restrained by tripterine. The expression of CXCL2 was distinctly decreased and miR-532-5p level was increased by tripterine in vivo.

Conclusion

In conclusion, tripterine inhibits the growth, migration ability and invasiveness of HCC cells through intervening miR-532-5p/CXCL2.