MicroRNA-497 regulates cell proliferation in hepatocellular carcinoma

MicroRNA-497-5p Is Downregulated in Hepatocellular Carcinoma and Associated with Tumorigenesis and Poor Prognosis in Patients

Background

MicroRNAs (miRNAs) have been demonstrated to exhibit important regulatory roles in multiple malignancies, including hepatocellular carcinoma (HCC). hsa-miR-497-5p was reported to involve in cancer progression and poor prognosis in many kinds of tumors. However, the expression and its clinical significance of hsa-miR-497-5p in HCC remain unclear.

Methods

In the present study, we investigated the expression of hsa-miR-497-5p in HCC and analyzed the correction of clinical features with prognosis. The expression levels of hsa-miR-497-5p and potential target genes were analyzed in HCC and adjacent noncancerous tissues using The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) datasets. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to analyze hsa-miR-497-5p levels in 328 HCC tissues and 30 paired adjacent noncancer tissues. Overall survival (OS) and progression-free survival (PFS) of patients with HCC were assessed using the Kaplan-Meier method and the log-rank test.

Results

The hsa-miR-497-5p expression levels were decreased, and its target genes ACTG1, CSNK1D, PPP1CC, and BIRC5 were upregulated in HCC tissues compared with normal tissues. Lower levels of hsa-miR-497-5p expression and higher levels of the four target genes were significantly associated with higher tumor diameter. Moreover, patients with lower hsa-miR-497-5p expression and higher target genes levels had shorter OS.

Conclusion

The expression levels of hsa-miR-497-5p may play an important regulatory role in HCC and are closely correlated with HCC progression and poor prognosis in patients. The hsa-miR-497-5p may be a specific therapeutic target for the treatment of HCC.

miR-497-5p Decreased Expression Associated with High-Risk Endometrial Cancer

The current guidelines for diagnosis, prognosis, and treatment of endometrial cancer (EC), based on clinicopathological factors, are insufficient for numerous reasons; therefore, we investigated the relevance of miRNA expression profiles for the discrimination of different EC subtypes. Among the miRNAs previously predicted to allow distinguishing of endometrioid ECs (EECs) according to different grades (G) and from serous subtypes (SECs), we verified the utility of miR-497-5p. In ECs, we observed downregulated miR-497-5p levels that were significantly decreased in SECs, clear cell carcinomas (CCCs), and carcinosarcomas (CaSas) compared to EECs, thereby distinguishing EEC from SEC and rare EC subtypes. Significantly reduced miR-497-5p expression was found in high-grade ECs (EEC G3, SEC, CaSa, and CCC) compared to low-grade carcinomas (EEC G1 and mucinous carcinoma) and ECs classified as being in advanced FIGO (International Federation of Gynecology and Obstetrics) stages, that is, with loco-regional and distant spread compared to cancers located only in the uterus. Based on immunohistochemical features, lower miR-497-5p levels were observed in hormone-receptor-negative, p53-positive, and highly Ki-67-expressing ECs. Using a machine learning method, we showed that consideration of miR-497-5p expression, in addition to the traditional clinical and histopathologic parameters, slightly improves the prediction accuracy of EC diagnosis. Our results demonstrate that changes in miR-497-5p expression influence endometrial tumorigenesis and its evaluation may contribute to more precise diagnoses.

Hepigenetics: A Review of Epigenetic Modulators and Potential Therapies in Hepatocellular Carcinoma

Hepatocellular carcinoma is the fifth most common cancer worldwide and the second most lethal, following lung cancer. Currently applied therapeutic practices rely on surgical resection, chemotherapy and radiotherapy, or a combination thereof. These treatment options are associated with extreme adversities, and risk/benefit ratios do not always work in patients' favor. Anomalies of the epigenome lie at the epicenter of aberrant molecular mechanisms by which the disease develops and progresses. Modulation of these anomalous events poses a promising prospect for alternative treatment options, with an abundance of felicitous results reported in recent years. Herein, the most recent epigenetic modulators in hepatocellular carcinoma are recapitulated on.

Inflammatory Micro-environment Contributes to Stemness Properties and Metastatic Potential of HCC via the NF-κB/miR-497/SALL4 Axis

Increasing evidence has demonstrated the essential role of inflammatory micro-environment in tumorigenesis and tumor progression. Some cancer cells in tumor maintain typical stemness properties and, with the capacity of self-renewal, are thought to be crucial for the initiation and maintenance of tumors as well as their metastasis. Although both inflammatory micro-environment and stemness properties played crucial roles in tumor initiation and development, currently it is still unclear whether and how the inflammatory micro-environment promotes cancer stemness properties. Here, we show the first evidence that the inflammatory micro-environment promotes the stemness properties and metastatic potential of hepatocellular carcinoma (HCC) via the NF-κB/miR-497/SALL4 axis. We discover that miR-497 directly targets SALL4, negatively regulates its expression, and further inhibits the self-renewal and metastasis of HCC; more importantly, inflammatory factor TNF-α inhibits the expression of miR-497 via NF-kB-mediated negative transcriptional regulation and simultaneously upregulates the expression of SALL4 and promotes the self-renewal and metastasis phenotypes of HCC cells. Moreover, lower expression of miR-497 is significantly associated with poor prognosis in HCC patients. Taken together, our findings not only revealed a novel signaling pathway (NF-κB/miR-497/SALL4 axis) to connect inflammation with stemness properties, and clarified the molecular mechanisms underlying the inflammation-mediated self-renewal and metastasis phenotypes, but also provided novel molecular targets for developing new anticancer strategies.

miR-497 inhibits the carcinogenesis of hepatocellular carcinoma by targeting the Rictor/Akt signal pathway

MicroRNAs (miRNAs) are involved in regulating various physiologic and pathologic processes of different human diseases including hepatocellular carcinoma (HCC). Our research aimed to investigate the role of miR-497 in migration, invasive ability of HepG2-GS cells and the regulating mechanism. In this study, Rictor was identified as a target gene of miR-497 by informatic software, including Microcosm Targets, miRanda, and TargetScan. MiR-497 or Rictor were silenced or overexpressed in HepG2-GS cells through transfection. The functional assay results showed that Rictor knockdown inhibited cancer cell proliferation, migration and invasion. Overexpression of Rictor inversed the effects of miR-497 on cancer cells growth inhibition. miR-497 regulated protein kinase B, PKB (Akt) signaling pathway by targeting Rictor. MiR-497 increased chemo-sensitivity of HepG2-GS through regulation of Rictor. In conclusion, our research demonstrated that miR-497 inhibits the proliferation, invasion, metastasis, and chemotherapy resistance of hepatoma cells by targeting of Rictor/Akt signal pathway, and miR-497. Thus, Rictor has the potential to be a explored as a biomarker or therapeutic target for diagnosis and treatment of HCC.

miR-497 may enhance the sensitivity of non-small cell lung cancer cells to gefitinib through targeting the insulin-like growth factor-1 receptor

Background

Recently, studies have demonstrated that microRNA-497 (miR-497) plays an important role in modulating tumor cell sensitivity to chemotherapeutic drugs; however, its role in cellular resistance to the effects of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in treatment of non-small cell lung cancer (NSCLC) is not fully understood. In this study, we explored the potential of miR-497 in targeting the insulin-like growth factor-1 receptor (IGF-1R) signaling pathways to overcome gefitinib resistance.

Methods

A gefitinib resistant human lung adenocarcinoma A549 cell line (A549/GR) was established by the method of gefitinib mutagenesis culture. Next, the A549/GR cells were transfected with miR-497 mimics to establish an miR-497 overexpression model, designated A549/GR-miR497-mimic. MTT assay was used to assess cell resistance to gefitinib, and western blot assay was employed to evaluate alterations of IGF-1R and the AKT1 signaling pathway.

Results

We found that A549/GR-miR497-mimic cells (IC50 =33.76±0.97 µmol/L) were more sensitive to gefitinib than the control group (P<0.01). In addition, the expression levels of IGF-1R and phosphorylated AKT1 (p-AKT1) in A549/GR-miR497-mimic cells were reduced.

Conclusions

We demonstrated that miR-497 may have the effect of reversing gefitinib resistance and increasing the sensitivity of NSCLC cells to EGFR-TKIs by inhibiting the expression of IGF-1R and reducing activation of the downstream AKT signaling pathway. Thus, miR-497 plays a vital role in the acquired resistance to EGFR-TKIs, and it may represent a potential therapeutic strategy to treat NSCLC exhibiting resistance to EGFR-TKIs.

RETRACTED: MicroRNA-497 promotes proliferation and inhibits apoptosis of cardiomyocytes through the downregulation of Mfn2 in a mouse model of myocardial ischemia-reperfusion injury

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. An Expression of Concern for this article was previously published while an investigation was conducted (see related editorial: https://doi.org/10.1016/j.biopha.2022.113812). This retraction notice supersedes the Expression of Concern published earlier. Concern was raised about the reliability of the images shown in Figure 1, and the Western blots in Figures 6C and 8E, which appear to contain similar features to those found in other publications, as detailed here: https://pubpeer.com/publications/5E5DF69C11DAD50FBE63CD4F95990F; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. Additional concerns were raised over the provenance of the flow cytometry data in Figure 10C, that appear to contain repeating features. Furthermore, the myocardial infarct images in Figure 5A appear to actually show brain slices. Independent analysis also identified additional suspected image duplications within Figures 3A and 4. The journal requested the corresponding author comment on these concerns and provide the associated raw data. The authors did not respond to this request and therefore the Editor-in-Chief decided to retract the article.

Genetic architecture and regulatory impact on hepatic microRNA expression linked to immune and metabolic traits

Regulation of microRNA (miRNA) expression contributes to a wide range of target gene expression and phenotypes. The miRNA expression in the liver, the central metabolic organ, was examined in 209 pigs, and integrated with haematological and clinical biomarkers of metabolic and overall health, mRNA-target expression levels and single-nucleotide polymorphism (SNP) genotypes. The expression levels of 426 miRNA species correlated with plasma haematological or biochemical traits (r² = |0.19–0.45|, false discovery rate < 5%). Pairs of these miRNAs and their predicted target mRNAs showing expressing levels associated with the identical traits were examined to understand how immune and metabolic traits are affected by miRNA-mediated regulatory networks derived by mapping miRNA abundance as an expression quantitative trait. In total, 221 miRNA-expression-QTL correspond to 164 SNPs and 108 miRNAs, including miR-34a, miR-30e, miR-148-3p, miR-204, miR-181-5p, miR-143-5p and let-7 g that also correlate with the biomarkers. Sixty-one SNPs were simultaneously associated with 29 miRNA and 41 mRNA species. The expression levels of 13 out of 29 miRNA were correlated with one of the biochemical or haematological traits. For example, the expression levels of miR-34a were correlated with serum phosphorus and cholesterin levels; miR-204, miR-15a and miR-16b were correlated with triglyceride. For haematological traits, the expression levels of miR-652 and miR-204 were correlated with the mean corpuscular haemoglobin concentration, and the expression of miR-143 was correlated with plateletcrit. Pleiotropic association analyses revealed genetic links between mRNA and miRNA on SSC6 for miR-34a, SSC9 for miR-708 and SSC14 for miR-652. Our analysis of miRNA and mRNA transcript profiles, their correlation with clinically important plasma parameters of hepatic functions as well as information on their genetic regulation provide novel regulatory networks and potential new biomarkers for immune and metabolic traits.

Identification of micro-RNA expression profile related to recurrence in women with ESMO low-risk endometrial cancer

Background

Actual European pathological classification of early-stage endometrial cancer (EC) may show insufficient accuracy to precisely stratify recurrence risk, leading to potential over or under treatment. Micro-RNAs are post-transcriptional regulators involved in carcinogenic mechanisms, with some micro-RNA patterns of expression associated with EC characteristics and prognosis. We previously demonstrated that downregulation of micro-RNA-184 was associated with lymph node involvement in low-risk EC (LREC). The aim of this study was to evaluate whether micro-RNA signature in tumor tissues from LREC women can be correlated with the occurrence of recurrences.

Methods

MicroRNA expression was assessed by chip analysis and qRT-PCR in 7 formalin-fixed paraffin-embedded (FFPE) LREC primary tumors from women whose follow up showed recurrences (R+) and in 14 FFPE LREC primary tumors from women whose follow up did not show any recurrence (R−), matched for grade and age. Various statistical analyses, including enrichment analysis and a minimum p-value approach, were performed.

Results

The expression levels of micro-RNAs-184, -497-5p, and -196b-3p were significantly lower in R+ compared to R− women. Women with a micro-RNA-184 fold change < 0.083 were more likely to show recurrence (n = 6; 66%) compared to those with a micro-RNA-184 fold change > 0.083 (n = 1; 8%), p = 0.016. Women with a micro-RNA-196 fold change < 0.56 were more likely to show recurrence (n = 5; 100%) compared to those with a micro-RNA-196 fold change > 0.56 (n = 2; 13%), p = 0.001.

Conclusions

These findings confirm the great interest of micro-RNA-184 as a prognostic tool to improve the management of LREC women.

MicroRNA-381 inhibits cell proliferation and invasion in endometrial carcinoma by targeting the IGF-1R

Endometrial carcinoma (EC) is the sixth most common type of malignant tumor occurring in females. MicroRNAs (miRNAs) serve as oncogenes or tumor suppressors in human cancer and play important roles in tumorigenesis, and tumor development by regulating various processes. Thus, further investigation into miRNAs involved in EC formation and progression may aid in developing effective therapeutic strategies for patients with this disease. miRNA‑381 (miR‑381) is aberrantly expressed in multiple types of human cancer. However, the expression pattern, biological roles and underlying mechanisms of miR‑381 in EC are poorly understood. In the present study, the results showed that miR‑381 was downregulated in EC tissues and cell lines. Decreased miR‑381 expression correlated with the International Federation of Gynecology and Obstetrics stage, lymph nodes metastasis and myometrial invasion of EC. The ectopic expression of miR‑381 significantly inhibited the proliferation and invasion of EC cells. Through a series of experiments, the insulin‑like growth factor receptor 1 (IGF‑1R) was identified as a novel direct target of miR‑381 in EC. Furthermore, IGF‑1R was highly expressed in EC tissues and inversely correlated with miR‑381 levels. IGF‑1R overexpression partially abrogated the tumor‑suppressive effects of miR‑381 on the proliferation and invasion of EC cells. miR‑381 targeted IGF‑1R to inactivate the protein kinase B (AKT) and extracellular signal‑regulated kinase (ERK) signaling pathways in EC. These results suggest that miR‑381 acts as a tumor suppressor in EC by directly targeting IGF‑1R, and indirectly regulating the AKT and ERK signaling pathways. Thus, miR‑381 should be investigated as a prognostic biomarker and novel therapeutic target for the treatment of patients with EC.

Down-regulation of MiR-365 as a novel indicator to assess the progression and metastasis of hepatocellular carcinoma

MicroRNAs (miRNAs) are involved in the pathogenesis of diverse types of malignancies, including hepatocellular carcinoma (HCC). However, miR-365 has rarely been reported in HCC. The purpose of the current study was to identify the clinical relevance of miR-365 in HCC and examine the potential downstream signaling effectors.Using real-time RT-qPCR, we confirmed that miR-365 expression was markedly decreased in HCC tissues (3.5138 ± 2.2527) compared to that in paraneoplastic liver tissues (6.5950 ± 4.1230, P<0.001). Receiver operating characteristic curves to assess the diagnostic value of miR-365 in HCC demonstrated that the area under the curve was 0.757. Furthermore, down-regulation of miR-365 was remarkably correlated to the number of tumor nodes, status of metastasis, clinical TNM stage, portal vein tumor embolus and vaso-invasion. In addition to the clinical value of miR-365, a total of 238 downstream direct targets selected by online predictive algorithms and key genes generated from natural language processing and the Cancer Genome Atlas (TCGA) were pooled for bioinformatics analysis. These potential targets were mainly enriched in the Ras Pathway using PANTHER analysis and the 'Pathways in Cancer' using Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. In conclusion, down-regulated miR-365 may contribute to the progression and metastasis of HCC via targeting multiple signaling pathways, and miR-365 may act as a novel biomarker for HCC.

MicroRNA‑497 inhibits cellular proliferation, migration and invasion of papillary thyroid cancer by directly targeting AKT3

Thyroid cancer is the most common tumor of the endocrine organs. Emerging studies have indicated the critical roles of microRNAs (miRs) in papillary thyroid cancer (PTC) formation and progression through function as tumor suppressors or oncogenes. The present study investigated the expression level and biological roles of miR-497 in PTC and its underlying mechanisms. It was demonstrated that the expression level of miR-497 was reduced in both PTC tissues and cell lines. Enforced expression of miR-497 suppressed PTC cell proliferation, migration and invasion. According to bioinformatics analysis, a luciferase reporter assay, reverse transcription-quantitative polymerase chain reaction and western blotting, RAC-γ serine/threonine-protein kinase (AKT3) was demonstrated to be the direct target gene of miR-497. In addition, AKT3 expression increased in PTC tissues and negatively correlated with miR-497 expression. Furthermore, downregulation of AKT3 also suppressed cell proliferation, migration and invasion of PTC, which had similar roles to miR-497 overexpression in PTC cells. Taken together, these results suggested that this newly identified miR-497/AKT3 signaling pathway may contribute to PTC occurrence and progression. These findings provide novel potential therapeutic targets for the therapy of PTC.