Long noncoding RNA MEG3 is downregulated in cervical cancer and affects cell proliferation and apoptosis by regulating miR-21

Nie

et al. 2017

Cell Physiol Biochem

Background/Aims: Increasing evidence has demonstrated a significant role of long non-coding RNAs (lncRNAs) in diverse biological processes, and many of which are likely to have functional roles in vascular remodeling. However, their functions in pulmonary arterial hypertension (PAH) remain largely unknown. Pulmonary vascular remodeling is an important pathological feature of PAH, leading to increased vascular resistance and reduced compliance. Pulmonary artery smooth muscle cells (PASMCs) dysfunction is involved in vascular remodeling. Long noncoding RNAs are potential regulators of PASMCs function. Herein, we determined whether long noncoding RNA–maternally expressed gene 3 (MEG3) was involved in PAH-related vascular remodeling. Methods: The arterial wall thickness was examined by hematoxylin and eosin (H&E) staining in distal pulmonary arteries (PAs) isolated from lungs of healthy volunteers and PAH patients. The expression level of MEG3 was analyzed by qPCR. The effects of MEG3 on human PASMCs were assessed by cell counting Kit-8 assay, BrdU incorporation assay, flow cytometry, scratch-wound assay, immunofluorescence, and western blotting in human PASMCs. Results: We revealed that the expression of MEG3 was significantly downregulated in lung and PAs of patients with PAH. MEG3 knockdown affected PASMCs proliferation and migration in vitro. Moreover, inhibition of MEG3 regulated the cell cycle progression and made more smooth muscle cells from the G₀/G₁ phase to the G₂/M+S phase and the process could stimulate the expression of PCNA, Cyclin A and Cyclin E. In addition, we found that the p53 pathway was involved in MEG3–induced smooth muscle cell proliferation. Conclusions: This study identified MEG3 as a critical regulator in PAH and demonstrated the potential of gene therapy and drug development for treating PAH.

Section: Resultsmentioning

confidence: 99%

Long Non-Coding RNA MEG3 Downregulation Triggers Human Pulmonary Artery Smooth Muscle Cell Proliferation and Migration via the p53 Signaling Pathway

Nie

et al. 2017

Cell Physiol Biochem

“…Besides, an increasing study have evidenced that lncRNAs can act as a competing endogenous RNA (ceRNA) via sponging miRNAs [13, 14]. In previous studies, MEG3 has been described to be a ceRNA that regulate miR-21 [15, 16], miR-1297 [17], and miR-140-5p [18]. Thus, we speculated that MEG3 may serve as a ceRNA which connecting some other miRNAs in pNETs.…”

Section: Introductionmentioning

confidence: 99%

MEG3 Suppresses Human Pancreatic Neuroendocrine Tumor Cells Growth and Metastasis by Down-Regulation of Mir-183

Zhang

Feng

2017

Cell Physiol Biochem

Background/Aims: Pancreatic neuroendocrine tumors (pNETs) are rare neoplasms which arise from pancreatic islet cells. Recently, lncRNA MEG3 has been reported as a tumor suppressor in variety cancers. This study aimed to reveal the functional effects of MEG3 on pNETs which has not been uncovered previously. Methods: The expression of MEG3, miR-183, and BRI3 in BON1 cells were altered by transfection with their specific vectors/shRNA, or mimic/inhibitor. Thereafter, cell viability, apoptosis, the protein expressions of cell cycle related factors, and apoptosis associated factors, as well as cell migration and invasion were respectively assessed by typan blue staining, flow cytometry, western blotting, and transwell assay. Results: MEG3 was low expressed in BON1 and QGP-1 cells, when compared to three normal cell lines (HEK293, CCL-153, and EC-304). MEG3 overexpression decreased BON1 cells viability, invasion, migration, but significantly induced apoptosis. miR-183 was a direct target of MEG3, and miR-183 up-regulation abolished the anti-growth and anti-metastasis effects of MEG3 overexpression on BON1 cells. Moreover, BRI3 was a target of miR-183, and BRI3 exhibited a tumor-promoting role possibly via activation of p38/ERK/AKT and Wnt/β-Catenin signaling in BON1 cells. Conclusion: This study demonstrated a tumor suppressive effect of MEG3 in BON1 cells that suppresses tumor cells growth and metastasis. A novel regulatory mechanism has been revealed that modulation of MEG3/miR-183/BRI3 axis may be pivotal in pNET.

“…[4][5][6][7] Recent literatures reported that aberrant lncRNA expression is observed in almost all malignant human tumors and is involved in tumorigenesis by acting as oncogenes or tumor suppressor genes. [8][9][10] Tumor suppressor candidate 7 (TUSC7) is an antisense RNA gene consisted of four exons and located at 3q13.3. 11 TUSC7 has no protein-coding potential and belongs to lncRNAs.…”

Section: Introductionmentioning

confidence: 99%

Long non-coding RNA tumor suppressor candidate 7 advances chemotherapy sensitivity of endometrial carcinoma through targeted silencing of miR-23b

Shang

Liu

et al. 2017

Tumour Biol.

Endometrial carcinoma is the most common malignant tumor of the female genital tract worldwide. TUSC7 (tumor suppressor candidate 7) is an antisense long non-coding RNA and is downregulated and acts as a potential tumor suppressor in several malignant tumors. In this study, the low expression of TUSC7 was confirmed in endometrial carcinoma tissues and was associated with high pathological stages of endometrial carcinoma, which revealed that TUSC7 might be involved in tumorigenesis and progression of endometrial carcinoma. Moreover, the expression of TUSC7 in endometrial carcinoma tissues and cell lines resistant to CDDP and Taxol was lower than that in sensitive endometrial carcinoma tissues and cell lines, which indicated that the TUSC7 expression level was positively correlated with the response of endometrial carcinoma patients to chemotherapy with CDDP and Taxol. TUSC7 upregulation inhibited proliferation, blocked cells at G1 phase, and advanced apoptosis and chemotherapy sensitivity to CDDP and Taxol in HEC1A/CR cell line. Furthermore, miR-23b was upregulated in endometrial carcinoma and negatively correlated with the expression of TUSC7. RNA pull-down assay indicated that TUSC7 could specifically silence the expression of miR23b in HEC1A/CR cell line; miR-23b was a target gene of TUSC7. MiR-23b upregulation mostly reversed the TUSC7-induced regulatory effects on HEC1A/CR cell line. In summary, long non-coding RNA TUSC7 was underexpressed in endometrial carcinoma, especially in endometrial carcinoma chemotherapy-resistant tissues and cell lines and acted as a potential tumor suppressor gene to inhibit cell growth as well as advance the chemotherapy sensitivity through targeted silencing of miR-23b, which might provide a new therapeutic target to endometrial carcinoma.