Two lncRNAs, MACC1-AS1 and UCA1, co-mediate the expression of multiple mRNAs through interaction with individual miRNAs in breast cancer cells

BACKGROUND

Increasing studies have shown that lncRNAs often play roles through interaction with miRNAs to control gene expression by inhibiting translation or facilitating degradation of target mRNAs. Here, we report that two lncRNAs, MACC1-AS1 and UCA1 are coordinately expressed in breast cancer cells and share the ability to interact with multiple miRNAs to mediate the expression of different genes.

METHODS

Targetscan, starBase and miRDB databases were used to predict the relationships of MACC1-AS1/UCA1-miRNA-mRNA network. qRT-PCR, and RNA sequencing were used to study the differential expression of lncRNAs and miRNA-targeted genes in breast cancer cells. RIP, RNA pull-down and luciferase assays were performed to confirm the molecular interactions of MACC1-AS1 or UCA1 with predicted miRNAs. The role of lncRNA-mediated miRNA-mRNA interactions in cell proliferation was examined by MTT assays following loss-of-function and gain-of-function effects.

RESULTS

We identified a lncRNA-miRNA-mRNA regulatory network in breast cancer cells, in which a number of mRNAs can be co-regulated by MACC1-AS1 and UCA1 lncRNAs. Each lncRNA possesses the capacity as a ceRNA to compete with various mRNA-targeting miRNAs. Interaction of MACC1-AS1 or UCA1 with individual miRNAs is able to increase the expression of the same target mRNAs, such as TBL1X and MEF2D, thus affecting cancer-cell growth phenotype.

CONCLUSIONS

Our study suggests that in each cell type, there is a balance of interactions between certain lncRNAs and miRNAs. Disrupting the balance would eventually affect the expression of miRNA-targeted genes and cell proliferation.

IFN-γ affects pancreatic cancer properties by MACC1-AS1/MACC1 axis via AKT/mTOR signaling pathway

BACKGROUND

Metastasis-related in colon cancer 1 (MACC1) is highly expressed in a variety of solid tumours, but its role in pancreatic cancer (PC) remains unknown. Interferon gamma (IFN-γ) affecting MACC1 expression was explored as the potential mechanism following its intervention.

METHODS

Expressions of MACC1 treated with IFN-γ gradient were confirmed by quantitative real-time PCR (qRT-PCR) and western blot (WB). Proliferation, migration, and invasion abilities of PC cells treated with IFN-γ were analysed by CCK8, EDU, colony formation, Transwell (with or without matrix gel) and wound-healing assays. Expression of antisense long non-coding RNA of MACC1, MACC1-AS1, and proteins of AKT/mTOR pathway, (pho-)AKT, and (pho-)mTOR was also assessed by qRT-PCR and WB. SiRNA kit and lentiviral fluid were conducted for transient expression of MACC1 and stable expression of MACC1-AS1, respectively. Rescue assays of cells overexpressing MACC1-AS1 and of cells silencing MACC1 were performed and cellular properties and proteins were assessed by the above-mentioned assays as well.

RESULTS

IFN-γ inhibited MACC1 expression in a time- and dose-dependent manner; 100 ng/mL IFN-γ generally caused downregulation of most significant (p ≤ 0.05). In vitro experiments revealed that IFN-γ decreased cellular proliferation, migration, and invasion abilities and downregulated the expression of pho-AKT and pho-mTOR (p ≤ 0.05). Conversely, overexpression of MACC1-AS1 upregulated pho-AKT and pho-mTOR proteins, and reversed cellular properties (p ≤ 0.05). Rescue assays alleviated the above changes of pho-AKT/ mTOR and cellular properties.

CONCLUSION

IFN-γ affected PC properties by MACC1-AS1/MACC1 axis via AKT/mTOR signaling pathway, which provides novel insight for candidate targets for treating PC.

Long noncoding RNA MACC1-AS1 promotes the stemness of hepatocellular carcinoma cells by antagonizing miR-145

Objectives

This work aimed to investigate the roles of long noncoding (lnc)RNA MACC1-AS1 (MACC1 antisense RNA 1) in progression of hepatocellular carcinoma (HCC).

Methods

Real-time quantitative PCR, western blot, spheroid formation, aldehyde dehydrogenase isoform 1 (ALDH1) activity analysis, luciferase reporter assay, and RNA pull-down analysis were used to examine MACC1-AS1–mediated effects on HCC cell stemness.

Results

MACC1-AS1 was highly expressed in HCC tissues and cells. MACC1-AS1 positively regulated the expression of stemness master regulators and inhibited spheroid-forming ability and ALDH1 activity. Furthermore, MACC1-AS1 promoted the stemness of HCC cells by antagonizing microRNA (miR)-145 activity. Overexpression of miR-145 also attenuated HCC cell stemness.

Conclusions

This work revealed a novel MACC1-AS1/miR-145 axis that regulates the stemness of HCC cells.

Long non-coding RNAs MACC1-AS1 and FOXD2-AS1 mediate NSD2-induced cisplatin resistance in esophageal squamous cell carcinoma

The nuclear receptor-binding SET domain (NSD) protein family encoding histone lysine methyltransferases is involved in cancer progression. However, the role of NSDs in esophageal squamous cell carcinoma (ESCC) remains unclear. Here we examined the expression of NSDs in cisplatin-resistant and parental ESCC cells and revealed the upregulation of NSD2 in cisplatin-resistant cells. Ectopic expression of NSD2 increased cisplatin resistance and attenuated cisplatin-induced apoptosis. Colony formation assay indicated that NSD2 overexpression enhanced long-term survival of ESCC cells after treatment with cisplatin. In contrast, knockdown of NSD2 inhibited ESCC cell proliferation and sensitized ESCC cells to cisplatin. Depletion of NSD2 augmented the cytotoxic effect of cisplatin on EC109 xenograft tumors. NSD2 stimulated long non-coding RNA MACC1-AS1 in ESCC cells. Knockdown of MACC1-AS1 impaired NSD2-induced cisplatin resistance. Moreover, MACC1-AS1 overexpression promoted ESCC cell proliferation and cisplatin resistance. Clinically, MACC1-AS1 was upregulated in ESCC relative to adjacent noncancerous tissues. High MACC1-AS1 levels were significantly associated with reduced overall survival of ESCC patients. There was a positive correlation between MACC1-AS1 and NSD2 expression in ESCC specimens. Taken together, MACC1-AS1 induced by NSD2 mediates resistance to cisplatin in ESCC and may represent a novel target to improve cisplatin-based chemotherapy.

Long noncoding RNA MACC1-AS1 promotes the stemness of nonsmall cell lung cancer cells through promoting UPF1-mediated destabilization of LATS1/2

The roles of long noncoding RNA (lncRNA) MACC1-AS1 have been revealed in various tumors. This work aims to explore the roles of lncRNA MACC1-AS1 in the stemness of nonsmall cell lung cancer (NSCLC) cells and the underlying mechanism. We showed that overexpression of MACC1-AS1 enhanced the stemness of NSCLC cells, which is evident as the increased expression of cancer stem cell transcription factors, ALDH1 activity, and sphere-formation capacity, while knockdown of MACC1-AS1 decreased it. RNA-sequencing analysis revealed that the Hippo pathway was mostly enriched in NSCLC cell with MACC1-AS1 overexpression. Further mRNA and western blot analysis showed that ectopic expression of MACC1-AS1 regulated the expression LATS1/2, the critical regulator of Hippo pathway. Additionally, it was found that MACC1-AS1 interacted with up-frameshift 1 (UPF1) to modulate mRNA decay of LATS1/2. Overexpression of LAST1/2 attenuated the promoting effects of MACC1-AS1 overexpression on the stemness of NSCLC cells. Therefore, our results demonstrate the effects of the novel MACC1-AS1/UPF1/LATS1/2 axis in NSCLC cell stemness.

LncRNA MACC1-AS1 Promotes Lung Adenocarcinoma Cell Proliferation by Downregulating PTEN

Background: MACC1-AS1 is an oncogenic lncRNA in gastric cancer, which interacts with AMP-activated protein kinase (AMPK) to promote cancer development. AMPK is known to interact with phosphatase and tensin homolog (PTEN). Therefore, MACC1-AS1 may also have associations with PTEN. This study aimed to investigate the interactions between MACC1-AS1 and PTEN in lung adenocarcinoma (LUAD). Materials and Methods: This study recruited 64 LUAD patients admitted to The First People's Hospital of Wenling City. Gene and protein expression levels were determined by qPCR and western blot, respectively. Cell transfections were performed to assess gene interactions. Cell proliferation was evaluated by CCK-8 assay. Results: MACC1-AS1 was upregulated in LUAD and inversely correlated with the expression of PTEN. High expression levels of MACC1-AS1 in LUAD tissues were closely correlated with poor survival rate of LUAD patients. In LUAD cells, overexpression of MACC1-AS1 led to decreased expression of PTEN and increased proliferation rate of LUAD cells, while MACC1-AS1 silencing led to increased expression of PTEN and decreased proliferation rate of LUAD cells. Furthermore, overexpression of PTEN attenuated the effects of overexpressing MACC1-AS1. Conclusions: The authors' results demonstrated that MACC1-AS1 promoted cell proliferation by downregulating PTEN in LUAD cells.

The long non-coding RNA MACC1-AS1 promotes nasopharyngeal carcinoma cell stemness via suppressing miR-145-mediated inhibition on SMAD2/MACC1-AS1 axis

The promoting roles of the long non-coding RNA (lncRNA) MACC1-AS1 have been indicated in gastric and pancreatic cancer, however, its roles in nasopharyngeal carcinoma (NPC) progression are never been revealed. In this work, it was shown that lncRNA MACC1-AS1 was highly expressed in NPC tissues and cells relative to the adjacent tissues and nasal mucosa cells, respectively. Additionally, MACC1-AS1 expression was positively correlated with the high rate of lymph node metastasis and large tumor size. in vitro and in vivo experiments revealed that MACC1-AS1 knockdown reduced the stemness of NPC cells, which was indicated by the decrease of sphere-forming ability, ALDH1 activity, stemness marker expression and tumor-initiating capacity. Mechanistic research showed that MACC1-AS1 antagonized the activity of miR-145, which could target Smad2. In turn, smad2 directly bound to MACC1-AS1 promoter and thus increased MACC1-AS1 expression. Notably, knockdown of miR-145 or overexpression of Smad2 rescued the inhibition of MACC1-AS1 knockdown on the stemness of NPC cells. Therefore, these results demonstrate a novel MACC1-AS1/miR-145/Smad2 negative loop responsible for NPC cell stemness.

Long noncoding RNA MACC1-AS1 is a potential sponge of microRNA-34a in cervical squamous cell carcinoma and upregulates cyclin-dependent kinase 6

The present study aimed to investigate the role of long noncoding RNA MACC1-AS1 in cervical squamous cell carcinoma (CSCC). In the present study MACC1-AS1 expression as analyzed using reverse transcription-quantitative PCR. The interactions between MACC1-AS1 and miR-34a was analyzed via overexpression experiments. Cell cycle and proliferation analyses were performed to analyze the roles of MACC1-AS1 in regulating cancer cell cycle progression and cell proliferation. It was observed that MACC1-AS1 was upregulated in CSCC, and its expression levels were elevated with the increase in clinical stage. Bioinformatics analysis revealed that MACC1-AS1 may be a sponge of miR-34a, which can target cyclin-dependent kinase 6 (CDK6). In CSCC cells, MACC1-AS1 overexpression led to upregulation of CDK6, while miR-34a overexpression had the opposite effect and reduced the effects of MACC1-AS1 overexpression in co-transfected cells. Cell cycle and proliferation analyses demonstrated that MACC1-AS1 and CDK6 promoted cell cycle progression and cell proliferation. By contrast, miR-34a had the opposite effect on cell cycle proliferation and cell proliferation, reducing the effects induced by MACC1-AS1 overexpression. Therefore, the lncRNA MACC1-AS1 may serve as a sponge of miR-34a to upregulate CDK6, thereby promoting cell cycle progression and cell proliferation.

MACC1-AS1 promotes hepatocellular carcinoma cell invasion and proliferation by regulating PAX8

Long noncoding RNAs play vital roles in several biological processes, including cell growth and embryonic development. We showed that MACC1-AS1 was overexpressed in hepatocellular carcinoma (HCC) cells and tissues. The MACC1-AS1 expression level was dramatically upregulated in HCC samples compared to adjacent normal samples, and 77.5% (31 of 40) of HCC samples showed overexpression of MACC1-AS1. Ectopic MACC1-AS1 expression enhanced cell proliferation and cyclin D1 expression in both SMMC7721 and MHCC-97H cells. Ectopic expression of MACC1-AS1 promoted vimentin, N-cadherin and snail expression and decreased E-cadherin expression in both SMMC7721 and MHCC-97H cells. MACC1-AS1 overexpression also induced cell invasion in the same two cell lines. Furthermore, MACC1-AS1 overexpression enhanced PAX8 expression in HCC cells. The PAX8 level was dramatically increased in HCC samples compared to adjacent normal samples, and 75% (30 of 40) of HCC samples showed overexpression of PAX8. PAX8 expression was positively correlated with MACC1-AS1 expression in HCC samples. MACC1-AS1 overexpression promoted HCC cell proliferation, EMT and invasion through regulating PAX8. These results suggest that MACC1-AS1 acts as an oncogene in the development of HCC.

The lncRNA MACC1-AS1 promotes gastric cancer cell metabolic plasticity via AMPK/Lin28 mediated mRNA stability of MACC1

Background

Metabolic plasticity has been increasingly thought to be a determinant of tumor growth and metastasis. MACC1, a transcriptional regulator of MET, was recognized as an oncogene in gastric cancer (GC); however, its transcriptional or post-translational regulation was not clear. We previously reported the metabolic role of MACC1 in glycolysis to promote GC progression. MACC1-AS1 is the antisense lncRNA of MACC1, yet its function was previously unknown.

Methods

We profiled and analyzed the expression of MACC1-AS1 utilizing the TCGA database as well as in situ hybridization using 123 pairs of GC tissues and matched adjacent normal gastric mucosa tissues (ANTs). The biological role of MACC1-AS1 in cell growth and metastasis was determined by performing in vitro and in vivo functional experiments. Glycolysis and antioxidant capabilities were assayed to examine its metabolic function. Further, the specific regulatory effect of MACC1-AS1 on MACC1 was explored transcriptionally and post-transcriptionally.

Results

MACC1-AS1 was shown to be expressed significantly higher in GC tissues than in ANTs, which predicted poor prognosis in GC patients. MACC1-AS1 promoted GC cell proliferation and inhibited cell apoptosis under metabolic stress. Mechanistically, MACC1-AS1 stabilized MACC1 mRNA and post-transcriptionally augmented MACC1 expression. Further, MACC1-AS1 was shown to mediate metabolic plasticity through MACC1 upregulation and subsequent enhanced glycolysis and anti-oxidative capabilities, and this was suggested to be coordinated by the AMPK/Lin28 pathway.

Conclusions

Elevated expression of MACC1-AS1 in gastric cancer tissues is linked to poor prognosis and promotes malignant phenotype upon cancer cells. MACC1-AS1 is elevated under metabolic stress and facilitates metabolic plasticity by promoting MACC1 expression through mRNA stabilization. Our study implicates lncRNA MACC1-AS1 as a valuable biomarker for GC diagnosis and prognosis.

Electronic supplementary material

The online version of this article (10.1186/s12943-018-0820-2) contains supplementary material, which is available to authorized users.