[Expression of miR-454-3p and its effect on proliferation, invasion and metastasis of colon cancer]

[Silenced ANP32A inhibits the growth, invasion and migration of colorectal cancer in vitro via the inactivation of AKT pathway]

OBJECTIVE

To investigate the effect of ANP32A silencing on invasion and migration of colon cancer cells and the influence of the activity of AKT signaling pathway on this effect.

METHODS

Colorectal cancer HCT116 and SW480 were transfected with a small interfering RNA targeting ANP32A via a lentiviral vector. At 24, 48 and 72 h after the transfection, the changes in cell proliferation and AKT activity in the cells were detected using MTT assay and Western blotting, respectively. HCT116 and SW480 cells were treated with the AKT agonist SC79 or its inhibitor MK2206 for 24, 48, 72 and 96 h, and the changes in cell migration and invasion ability were analyzed using Transwell chamber assay and cell proliferation was assessed using MTT assay. The effects of SC79 and MK2206 on migration and invasion abilities of HCT116 and SW480 cells with or without ANP32A silencing were examined using wound healing and Transwell chamber assays, and the changes in the expression of metadherin (MTDH), a factor associated with cells invasion and migration, was detected with Western blotting.

RESULTS

Lentivirus-mediated ANP32A silencing significantly down-regulated the activity of AKT and inhibited the proliferation of both HCT116 and SW480 cells (P < 0.01). The application of AKT inhibitor MK2206 obviously inhibited the proliferation, invasion and migration of the colorectal cancer cells (P < 0.05), while the AKT agonist SC79 significantly promoted the invasion and migration of the cells (P < 0.01). In HCT116 and SW480 cells with ANP32A silencing, treatment with MK2206 strongly enhanced the inhibitory effects of ANP32A silencing on cell invasion and migration (P < 0.05) and the expression of MTDH, while SC79 partially reversed these inhibitory effects (P < 0.01).

CONCLUSION

ANP32A silencing inhibits invasion and migration of colorectal cancer cells possibly by inhibiting the activation of the AKT signaling pathway.

Tumor Suppressor 4.1N/EPB41L1 is Epigenetic Silenced by Promoter Methylation and MiR-454-3p in NSCLC

Non–small-cell lung cancer (NSCLC) is divided into three major histological types, namely, lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC), and large-cell lung carcinoma (LCLC). We previously identified that 4.1N/EPB41L1 acts as a tumor suppressor and is reduced in NSCLC patients. In the current study, we explored the underlying epigenetic mechanisms of 4.1N/EPB41L1 reduction in NSCLC. The 4.1N/EPB41L1 gene promoter region was highly methylated in LUAD and LUSC patients. LUAD patients with higher methylation level in the 4.1N/EPB41L1 gene promoter (TSS1500, cg13399773 or TSS200, cg20993403) had a shorter overall survival time (Log-rank p = 0.02 HR = 1.509 or Log-rank p = 0.016 HR = 1.509), whereas LUSC patients with higher methylation level in the 4.1N/EPB41L1 gene promoter (TSS1500 cg13399773, TSS1500 cg07030373 or TSS200 cg20993403) had a longer overall survival time (Log-rank p = 0.045 HR = 0.5709, Log-rank p = 0.018 HR = 0.68 or Log-rank p = 0.014 HR = 0.639, respectively). High methylation of the 4.1N/EPB41L1 gene promoter appeared to be a relatively early event in LUAD and LUSC. DNA methyltransferase inhibitor 5-Aza-2′-deoxycytidine restored the 4.1N/EPB41L1 expression at both the mRNA and protein levels. MiR-454-3p was abnormally highly expressed in NSCLC and directly targeted 4.1N/EPB41L1 mRNA. MiR-454-3p expression was significantly correlated with 4.1N/EPB41L1 expression in NSCLC patients (r = −0.63, p < 0.0001). Therefore, we concluded that promoter hypermethylation of the 4.1N/EPB41L1 gene and abnormally high expressed miR-454-3p work at different regulation levels but in concert to restrict 4.1N/EPB41L1 expression in NSCLC. Taken together, this work contributes to elucidate the underlying epigenetic disruptions of 4.1N/EPB41L1 deficiency in NSCLC.

Mechanism underlying long non‑coding RNA ILF3‑AS1‑mediated inhibition of cervical cancer cell proliferation, invasion and migration, and promotion of apoptosis

Long non-coding RNA ILF3 divergent transcript (ILF3-AS1) displays a tumor-suppressing effect. StarBase predicted that the potential target microRNA (miR) of ILF3-AS1 was miR-454-3p; therefore, the present study investigated the effect of ILF3-AS1 and its target miR-454-3p on cervical cancer (CC). Gene Expression Profiling Interactive Analysis was used to predict the expression of ILF3-AS1 in CC and the overall survival rate of patients. The present study demonstrated that ILF3-AS1 expression was significantly downregulated in human CC tissues and cells compared with adjacent tissues (ANTs) and normal cervical epithelial cells (NCEs), respectively. Patients with CC with high ILF3-AS1 expression displayed higher survival rates compared with patients with low ILF3-AS1 expression. Cell viability, apoptosis, migration and invasion were detected by performing Cell Counting Kit-8, flow cytometry, wound healing and Transwell assays, respectively. Compared with the negative control (NC) group, ILF3-AS1 overexpression significantly inhibited CC cell viability and migration, but significantly increased CC cell apoptosis. Moreover, ILF3-AS1 overexpression significantly upregulated E-Cadherin expression levels, but significantly downregulated N-Cadherin and snail family transcriptional repressor 1 expression levels compared with the NC group. miR-454-3p expression was negatively correlated with ILF3-AS1, and highly expressed in CC tissues and cells compared with ANTs and NCEs, respectively. PTEN, which was predicted and verified as the target gene for miR-454-3p, was significantly downregulated in CC tissues and cells compared with ANTs and NCEs, respectively. ILF3-AS1 expression was positively correlated with PTEN expression, and ILF3-AS1 overexpression partially reversed the inhibitory effect of miR-454-3p on PTEN expression. In conclusion, the present study indicated that ILF3-AS1 inhibited CC cell proliferation and migration, and promoted CC cell apoptosis by inhibiting epithelial-mesenchymal transition, and ILF3-AS1 overexpression partially reversed the inhibitory effect of miR-454-3p on PTEN expression.