miR-376a inhibits the proliferation and invasion of osteosarcoma by targeting FBXO11

Allicin Inhibits Osteosarcoma Growth by Promoting Oxidative Stress and Autophagy via the Inactivation of the lncRNA MALAT1-miR-376a-Wnt/β-Catenin Signaling Pathway

Allicin, an organic sulfur compound extracted from the bulb of Allium sativum, can potentially prevent various tumors. Our previous study found that allicin can effectively suppress the proliferation of osteosarcoma cells. However, the molecular mechanisms have not been illustrated. In this study, Saos-2 and U2OS osteosarcoma cells were used to investigate the underlying mechanisms. A series of experiments were carried out to authenticate the anticancer property of allicin. Knockdown of lncRNA MALAT1 inhibited the proliferation, invasion and migration and promoted apoptosis of osteosarcoma cells. Knockdown of miR-376a increased the proliferation, invasion, and migration and dropped apoptosis of osteosarcoma cells. Furthermore, knockdown of miR-376a reversed the influences of MALAT1 silencing in osteosarcoma cells. Based on our data, MALAT1 could downregulate the expression of miR-376a, subsequently accelerating osteosarcoma. Moreover, oxidative stress and autophagy were identified as the potential key pathway of allicin. Allicin inhibited osteosarcoma growth and promoted oxidative stress and autophagy via MALATI-miR-376a. We also found that allicin promotes oxidative stress and autophagy to inhibit osteosarcoma growth by inhibiting the Wnt/β-catenin pathway in vivo and in vitro. All data showed that allicin promotes oxidative stress and autophagy of osteosarcoma via the MALATI-miR-376a-Wnt/β-catenin pathway.

Ultrasound-targeted microbubble destruction-mediated silencing of FBXO11 suppresses development of pancreatic cancer

Ultrasound-targeted microbubble destruction (UTMD) has been a promising noninvasive tool for organ- or tissue-specific gene or drug delivery. This study aimed to explore the function of F-box protein 11 (FBXO11), an E3 ubiquitin ligase, in the development of pancreatic cancer (PCa). Differentially expressed genes in PCa were identified using the GSE62452 and GSE28735 datasets, and FBXO11 was significantly highly expressed in PCa. UTMD-mediated FBXO11 silencing significantly suppressed growth activity, epithelial-mesenchymal transition, migration, and invasion while reduced apoptosis of PCa cells in vitro and reduced the growth and metastasis of xenograft tumors in vivo. Importantly, UTMD-mediated sh-FBXO11 showed more pronounced tumor-suppressive effects than direct administration of sh-FBXO11 alone. The potential substrates of FBXO11 as an E3 ubiquitin ligase were predicted using the Ubibrowser. TP53 was predicted and validated as a downstream substrate of FBXO11. FBXO11 induced ubiquitination and degradation of the tumor suppressor protein TP53 to induce PCa progression. In conclusion, this study suggests that silencing of FBXO11, especially that mediated by UTMD, might suppress the malignant biological behaviors of PCa cells and serve as a potential therapeutic strategy for PCa management.

MAP17 contributes to non-small cell lung cancer progression via suppressing miR-27a-3p expression and p38 signaling pathway

PROBLEM AND AIM

The overexpression of MAP17 has been reported in various human carcinomas. However, its molecular mechanism in non-small cell lung cancer (NSCLC) has not been fully understood. Our study aimed to reveal the molecular mechanism of NSCLC that involved MAP17 and identify its target miRNA.

METHODS

RT-qPCR and immunoblot assays were conducted to measure the expression of mRNA and protein in NSCLC tissues and cell lines. Meanwhile, the A549 cells (an NSCLC cell line) were randomly assigned to the MAP17 overexpression group, the MAP17 knockdown group and negative control group to study the roles of MAP17 in cell viability, cell proliferation, migration, invasion, and apoptosis by performing Trypan blue exclusion, MTT, colony formation, transwell, wound healing and flow-cytometric apoptosis assays. The luciferase reporter assay was conducted to confirm the target relationship between MAP17 and miR-27a-3p.

RESULTS

The upregulation of MAP17 mRNA and protein was observed in NSCLC tissues and cell lines. In vitro, the positive roles of MAP17 on cell viability, migration, and invasion were confirmed in A549 cells. It was also found that MAP17 could inhibit cell apoptosis by suppressing the activation of the p38 pathway. This research eventually proved the target relationship between MAP17 and miR-27a-3p, and that miR-27a-3p reversed the effects of MAP17 in A549 cells by directly targeting MAP17.

CONCLUSIONS

MAP17 plays an oncogenic role in NSCLC by suppressing the activation of the p38 pathway. Apart from that, the miR-27a-3p can inhibit the expression of MAP17 to suppress the NSCLC progression.

LncRNA TTN‑AS1 promotes endometrial cancer by sponging miR‑376a‑3p

Increasing research has demonstrated that lncRNAs participate in the development of multiple cancer types. However, the role of TTN-AS1 in endometrial cancer (EC) remains unknown. The present study aimed to explore the function of titin-antisense RNA1 (TTN-AS1) in EC progression and the underlying mechanisms. qRT-PCR was performed to assess the TTN-AS1 expression patterns in EC tissues and cell lines. Loss of function experiments were carried out to estimate the effects of TTN-AS1 on EC cell proliferation, migration and invasion. To reveal the underlying mechanisms, informatics tools were used to predict the targets. Rescue experiments were performed to investigate the TTN-AS1-regulated miR-376a-3p/pumilio homolog 2 (PUM2) axis involved. The results of the present study revealed that TTN-AS1 was highly expressed in both EC tissues and cell lines, and TTN-AS1 knockdown inhibited EC cell proliferation, migration and invasion. With respect to the mechanisms, miR-376a-3p was revealed to be targeted by TTN-AS1, and reversed the effects on EC development induced by TTN-AS1. In addition, PUM2 was positively regulated by TTN-AS1, and miR-376a-3p mediated the regulation between them. Furtherly, in vivo experiments confirmed the results. Collectively, TTN-AS1 enhanced EC cell proliferation and metastasis by targeting the miR-376a-3p/PUM2 axis, which may shed light on EC diagnosis and treatment.

Long non-coding RNA NNT-AS1 regulates proliferation, apoptosis, inflammation and airway remodeling of chronic obstructive pulmonary disease via targeting miR-582-5p/FBXO11 axis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a kind of chronic lung disease that mainly induced by smoking-caused inflammation. Long non-coding RNAs (lncRNAs) have been reported to play a part in the course of pulmonary diseases. Here, we studied the role of lncRNA NNT-AS1 in the development of COPD.

MATERIALS

qRT-PCR analysis and ELISA assay were applied to evaluate the expression of genes and inflammatory cytokines, respectively. CCK8 and EdU assays were utilized to assess proliferation, while flow cytometry assay was conducted to evaluate apoptosis. Luciferase reporter, RNA pull down and RIP assays were combined to explore relationships between genes.

RESULTS

NNT-AS1 was observed to be up-regulated in cigarette smoke extract (CSE)-treated 16HBE cells. Knockdown of NNT-AS1 abolished CSE-caused suppressive effects on cell proliferation, apoptosis, inflammation and airway remodeling. Mechanistically, NNT-AS1 up-regulated FBXO11 expression via sponging miR-582-5p. Moreover, miR-582-5p inhibitor or FBXO11 overexpression counteracted NNT-AS1 silence-elicited effects on proliferation, apoptosis, inflammation and airway remodeling.

CONCLUSION

Our data revealed that NNT-AS1 played a promoting role in smoking-induced COPD via modulating miR-582-5p/FBXO11 signaling, suggesting a novel potential target for COPD treatment.

Retraction Note to: miR-376a inhibits the proliferation and invasion of osteosarcoma by targeting FBXO11

This article has been retracted by the editors because the data are unreliable. It appears that the images in Figure 4c have been re-used but labelled as different conditions. The authors were asked to provide raw data for this figure, but were unable to do so. Author Jianyang Chen stated on behalf of all co-authors that they agree to this retraction.

miR-324-5p upregulation potentiates resistance to cisplatin by targeting FBXO11 signalling in non-small cell lung cancer cells

Dysregulation of microRNAs (miRNAs) plays a key role during the pathogenesis of chemoresistance in lung cancer (LCa). Previous study suggests that miR-324-5p may serve as a unique miRNA signature for LCa, but its role and the corresponding molecular basis remain largely explored. Herein, we report that miR-324-5p expression was significantly increased in cisplatin (CDDP)-resistant LCa tissues and cells, and this upregulation predicted a poor post-chemotherapy prognosis in LCa patients. miR-324-5p was further shown to impact CDDP response: Ectopic miR-324-5p expression in drug-naïve LCa cells was sufficient to attenuate sensitivity to CDDP and to confer more robust tumour growth in CDDP-challenged nude mice. Conversely, ablation of miR-324-5p expression in resistant cells effectively potentiated CDDP-suppressed cell growth in vitro and in vivo. Using multiple approaches, we further identified the tumour suppressor FBXO11 as the direct down-stream target of miR-324-5p. Stable expression of FBXO11 could abrogate the pro-survival effects of miR-324-5p in CDDP-challenged LCa cells. Together, these findings suggest that miR-324-5p upregulation mediates, at least partially, the CDDP resistance by directly targeting FBXO11 signalling in LCa cells. In-depth elucidation of the molecular basis underpinning miR-324-5p action bears potential implications for mechanism-based strategies to improve CDDP responses in LCa.

miR-509-5p Inhibits the Proliferation and Invasion of Osteosarcoma by Targeting TRIB2

Osteosarcoma (OS) is one of the most common malignant bone tumors in adolescents with a poor prognosis. Though miR-509-5p has been reported as a tumor suppressor in several human cancers, the role of miR-509-5p in OS remains unclear. In this study, our result of real-time PCR (RT-PCR) showed that the expression of miR-509-5p was significantly decreased in OS tissues and cell lines. Overexpression of miR-509-5p significantly suppressed cell proliferation and invasion in OS cell lines. Moreover, we identified tribbles homolog 2 (TRIB2) as the direct target of miR-509-5p. Knockdown of TRIB2 could inhibit the malignant capacity of OS cells. At last, we reported that TRIB2 could inhibit the bioactivity of the tumor suppressor gene p21 via blocking its transcriptional activity. Collectively, our study revealed that miR-509-5p functions as a tumor suppressor by targeting TRIB2 in OS and thus could affect the activity of p21, suggesting that miR-509-5p is a novel preventive intervention for OS patients.

Tumor Suppressor Function of miR-127-3p and miR-376a-3p in Osteosarcoma Cells

Since the introduction of high-dose chemotherapy about 35 years ago, survival rates of osteosarcoma patients have not been significantly improved. New therapeutic strategies replacing or complementing conventional chemotherapy are therefore urgently required. MicroRNAs represent promising targets for such new therapies, as they are involved in the pathology of multiple types of cancer, and aberrant expression of several miRNAs has already been shown in osteosarcoma. In this study, we identified silencing of miR-127-3p and miR-376a-3p in osteosarcoma cell lines and tissues and investigated their role as potential tumor suppressors in vitro and in vivo. Transfection of osteosarcoma cells (n = 6) with miR-127-3p and miR-376a-3p mimics significantly inhibited proliferation and reduced the colony formation capacity of these cells. In contrast, we could not detect any influence of miRNA restoration on cell cycle and apoptosis induction. The effects of candidate miRNA restoration on tumor engraftment and growth in vivo were analyzed using a chicken chorioallantoic membrane (CAM) assay. Cells transfected with mir-127-3p and miR-376a-3p showed reduced tumor take rates and tumor volumes and a significant decrease of the cumulative tumor volumes to 41% and 54% compared to wildtype cells. The observed tumor suppressor function of both analyzed miRNAs indicates these miRNAs as potentially valuable targets for the development of new therapeutic strategies for the treatment of osteosarcoma.

LncRNA TTN-AS1 sponges miR-376a-3p to promote colorectal cancer progression via upregulating KLF15

AIMS

Long non-coding RNAs (lncRNAs) play key roles in regulating multiple cancers. TTN-AS1 was reported to function in several human malignancies. However, the biological function of TTN-AS1 in colorectal cancer (CRC) has not been explored. In this study, we aimed to investigate the role and the underlying mechanisms of TTN-AS1 in CRC progression.

MAIN METHODS

RT-qPCR was used to detect the expression levels of TTN-AS1, miR-376a-3p and KLF15 in colorectal cancer tissues and cells. CCK-8, colony formation, flow cytometry and transwell assays were performed to determine the cell proliferation, apoptotic rate and invasion ability. Target genes were predicted using bioinformatics methods. si-RNA and miRNA inhibitor were transfected into CRC cells to explore the underlying mechanisms. Tumor xenografts were created to confirm the function of TTN-AS-1 in vivo.

KEY FINDINGS

TTN-AS1 upregulation was observed both in CRC tissues and cell lines. Functional investigation showed that knockdown of TTN-AS1 inhibited CRC cell proliferation and invasion, while enhanced cell apoptosis. Bioinformatics analysis identified miR-376a-3p as a target of TTN-AS1. Transfection of miR-376a-3p inhibitor mitigated the alterations induced by TTN-AS1 knockdown. Moreover, TTN-AS1 positively regulated KLF15 via sponging miR-376a-3p. Additionally, these findings were supported by in vivo experiments.

SIGNIFICANCE

In conclusions, TTN-AS1 promoted CRC proliferation and invasion through miR-376a-3p/KLF15 axis. Our findings suggested that TTN-AS1 might be a potential therapeutic target in CRC treatment.

Long noncoding RNA TTN-AS1 enhances the malignant characteristics of osteosarcoma by acting as a competing endogenous RNA on microRNA-376a thereby upregulating dickkopf-1

The expression levels and detailed functions of TTN-AS1 in osteosarcoma (OS) have not yet been explored. This study aimed to measure TTN-AS1 expression in OS tissues and cell lines, investigate its specific roles in the aggressive characteristics of OS cells in vitro and in vivo, and elucidate the regulatory mechanisms of TTN-AS1 action. TTN-AS1 expression was high in OS tissue samples and cell lines; TTN-AS1 overexpression correlated with the clinical stage, distant metastasis, and shorter overall survival of the patients. A TTN-AS1 knockdown inhibited OS cell proliferation, migration, and invasion and induced apoptosis in vitro and slowed tumor growth in vivo. Mechanism investigation revealed that TTN-AS1 acts as a competing endogenous RNA on microRNA-376a-3p (miR-376a) in OS cells. Dickkopf-1 (DKK1) mRNA was identified as a direct target of miR-376a in OS cells. Resumption of DKK1 expression reversed the tumor-suppressive activities of miR-376a overexpression in OS cells. The knockdown of miR-376a counteracted the reduction in the malignant characteristics of OS cells by the downregulation of TTN-AS1. In conclusion, TTN-AS1 functions as a competing endogenous RNA targeting miR-376a and increases the malignancy of OS cells in vitro and in vivo by upregulating DKK1.