miR-122-5p Expression and Secretion in Melanoma Cells Is Amplified by the LPAR3 SH3–Binding Domain to Regulate Wnt1

MiR-122-5p regulates erastin-induced ferroptosis via CS in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a tumor that occurs in the nasopharynx. Although advances in detection and treatment have improved the prognosis of NPC the treatment of advanced NPC remains challenging. Here, we explored the effect of microRNA (miR)-122-5p on erastin-induced ferroptosis in NPC cells and the role of ferroptosis in the development of NPC. The effect of miR-122-5p silencing and overexpression and the effect of citrate synthase on erastin-induced lipid peroxidation in NPC cells was analyzed by measuring the amounts of malondialdehyde, Fe2+, glutathione, and reactive oxygen species and the morphological alterations of mitochondria. The malignant biological behavior of NPC cells was examined by cell counting kit-8, EDU, colony formation, Transwell, and wound healing assays. The effects of miR-122-5p on cell proliferation and migration associated with ferroptosis were examined in vivo in a mouse model of NPC generated by subcutaneous injection of NPC cells. We found that erastin induced ferroptosis in NPC cells. miR-122-5p overexpression inhibited CS, thereby promoting erastin-induced ferroptosis in NPC cells and decreasing NPC cell proliferation, migration, and invasion.

Identification of Prognostic Markers of DNA Damage and Oxidative Stress in Diagnosing Papillary Renal Cell Carcinoma Based on High-Throughput Bioinformatics Screening

Purpose

Papillary renal cell carcinoma (pRCC) is the second most common histological subtype of adult kidney tumors, with a poor prognosis due to limited understanding of the disease mechanism. Herein, we have performed high-throughput bioinformatic screening to explore and identify potential biomarkers of DNA damage and oxidative stress for pRCC.

Methods

RNA sequencing data related to pRCC were downloaded from the TCGA database, and differentially expressed genes (DEG) were identified by a wide variety of clustering and classification algorithms, including self-organized maps (SOM), artificial neural networks (ANN), support vector machines (SVM), fuzzy logic, and hyphenated techniques such as neuro-fuzzy networks. Then DAVID and STRING online biological information tools were used to analyze functional enrichment of the regulatory networks of DEG and construct a protein-protein interaction (PPI) network, and then the Cytoscape software was used to identify hub genes. The importance of key genes was assessed by the analysis of the Kaplan-Meier survival curves using the R software. Lastly, we have analyzed the expression of hub genes of DNA damage and oxidative stress (BDKRB1, NMUR2, PMCH, and SAA1) in pRCC tissues and adjacent normal tissues, as well as the relationship between the expression of hub genes in pRCC tissues and pathological characteristics and prognosis of pRCC patients.

Results

A total of 1,992 DEGs for pRCC were identified, with 1,142 upregulated ones and 850 downregulated ones. The DEGs were significantly enriched in activities including DNA damage and oxidative stress, chemical synaptic transmission, an integral component of the membrane, calcium ion binding, and neuroactive ligand-receptor interaction. cytoHubba in the Cytoscape software was used to determine the top 10 hub genes in the PPI network as BDKRB2, NMUR2, NMU, BDKRB1, LPAR5, KNG1, LPAR3, SAA1, MCHR1, PMCH, and NCAPH. Furthermore, the expression level of hub genes BDKRB1, NMUR2, PMCH, and SAA1 in pRCC tissues was significantly higher than that in the adjacent normal tissues. Meanwhile, the expression level of hub genes BDKRB1, NMUR2, PMCH, and SAA1 in pRCC tissues was significantly positively correlated with tumor stage, lymph node metastasis, and the histopathology grade of pRCC. In addition, high expression levels of hub genes BDKRB1, NMUR2, PMCH, and SAA1 were associated with a poor prognosis for patients with pRCC. Univariate and multivariate analyses showed that the expression of hub genes BDKRB1, NMUR2, PMCH, and SAA1 were independent risk factors for the prognosis of patients with pRCC.

Conclusion

The results of this analysis suggested that BDKRB1, NMUR2, PMCH, and SAA1 might be potential prognostic biomarkers and novel therapeutic targets for pRCC.

Elucidation of the mechanism of miR‑122‑5p in mediating FOXO3 injury and apoptosis of mouse cochlear hair cells induced by hydrogen peroxide

Unveiling the mechanism of miR-122-5p in the mediation of forkhead box O3 (FOXO3) in regards to cochlear hair cell damage provides an effective solution for the treatment of ear hearing disorders. An oxidative stress model using a mouse cochlear hair cell line (HEI-OC1) was established via hydrogen peroxide (H₂O₂). Then HEI-OC1 cells were transfected with miR-122-5p mimic, miR-122-5p inhibitor, and lentiviral vector FOXO3-WT/MUT. Cell viability and apoptosis rate were determined by MTT assay and flow cytometry. Reactive oxygen species (ROS) were observed by confocal laser scanning microscopy. Bcl-2, Bax, capase-3 and c-caspase-9 levels were quantified by western blot analysis and quantitative reverse transcription polymerase chain reaction (RT-qPCR). Enzyme-linked immunosorbent assay (ELISA) was used to detect superoxide dismutase (SOD) and malondialdehyde (MDA) levels, and flow cytometry was performed to measure the mitochondrial membrane potential levels. In the HEI-OC1 oxidative stress model after transfection, the miR-122-5p level was decreased, whereas the FOXO3 level was increased, Moreover, the increased FOXO3 level diminished the cell viability, but promoted cell apoptosis. Apart from this, the Bcl-2 level was downregulated, while levels of Bax, c-caspase-3, c-caspase-9, ROS and MDA were upregulated. Meanwhile, the mitochondrial membrane potential level was also elevated. Overexpression of miR-122-5p was able to partially offset the effects of FOXO3 in the H₂O₂-treated HEI-OC1 cells. Collectively, miR-122-5p restrained the decrease in HEI-OC1 cell viability and apoptosis induced by treatment with H₂O₂.

Indoleamine 2, 3 Dioxygenase 1 Impairs Chondrogenic Differentiation of Mesenchymal Stem Cells in the Joint of Osteoarthritis Mice Model

Osteoarthritis (OA) is a serious joint inflammation that leads to cartilage degeneration and joint dysfunction. Mesenchymal stem cells (MSCs) are used as a cell-based therapy that showed promising results in promoting cartilage repair. However, recent studies and clinical trials explored unsatisfied outcomes because of slow chondrogenic differentiation and increased calcification without clear reasons. Here, we report that the overexpression of indoleamine 2,3 dioxygenase 1 (IDO1) in the synovial fluid of OA patients impairs chondrogenic differentiation of MSCs in the joint of the OA mice model. The effect of MSCs mixed with IDO1 inhibitor on the cartilage regeneration was tested compared to MSCs mixed with IDO1 in the OA animal model. Further, the mechanism exploring the effect of IDO1 on chondrogenic differentiation was investigated. Subsequently, miRNA transcriptome sequencing was performed for MSCs cocultured with IDO1, and then TargetScan was used to verify the target of miR-122-5p in the SF-MSCs. Interestingly, we found that MSCs mixed with IDO1 inhibitor showed a significant performance to promote cartilage regeneration in the OA animal model, while MSCs mixed with IDO1 failed to stimulate cartilage regeneration. Importantly, the overexpression of IDO1 showed significant inhibition to Sox9 and Collagen type II (COL2A1) through activating the expression of β-catenin, since inhibiting of IDO1 significantly promoted chondrogenic signaling of MSCs (Sox9, COL2A1, Aggrecan). Further, miRNA transcriptome sequencing of SF-MSCs that treated with IDO1 showed significant downregulation of miR-122-5p which perfectly targets Wnt1. The expression of Wnt1 was noticed high when IDO1 was overexpressed. In summary, our results suggest that IDO1 overexpression in the synovial fluid of OA patients impairs chondrogenic differentiation of MSCs and cartilage regeneration through downregulation of miR-122-5p that activates the Wnt1/β-catenin pathway.

Tissue microRNA expression profiling in hepatic and pulmonary metastatic melanoma

Malignant melanoma has a propensity for the development of hepatic and pulmonary metastases. MicroRNAs (miRs) are small, noncoding RNA molecules containing about 22 nucleotides that mediate protein expression and can contribute to cancer progression. We aim to identify clinically useful differences in miR expression in metastatic melanoma tissue. RNA was extracted from formalin-fixed, paraffin-embedded samples of hepatic and pulmonary metastatic melanoma, benign, nevi, and primary cutaneous melanoma. Assessment of miR expression was performed on purified RNA using the NanoString nCounter miRNA assay. miRs with greater than twofold change in expression when compared to other tumor sites (P value ≤ 0.05, modified t-test) were identified as dysregulated. Common gene targets were then identified among dysregulated miRs unique to each metastatic site. Melanoma metastatic to the liver had differential expression of 26 miRs compared to benign nevi and 16 miRs compared to primary melanoma (P < 0.048). Melanoma metastatic to the lung had differential expression of 19 miRs compared to benign nevi and 10 miRs compared to primary melanoma (P < 0.024). Compared to lung metastases, liver metastases had greater than twofold upregulation of four miRs, and 4.2-fold downregulation of miR-200c-3p (P < 0.0081). These findings indicate that sites of metastatic melanoma have unique miR profiles that may contribute to their development and localization. Further investigation of the utility of these miRs as diagnostic and prognostic biomarkers and their impact on the development of metastatic melanoma is warranted.

ZEB1-AS1/miR-133a-3p/LPAR3/EGFR axis promotes the progression of thyroid cancer by regulating PI3K/AKT/mTOR pathway

Background

Thyroid cancer (TC) is a member of common malignant tumors in endocrine system. To develop effective treatment, further comprehension of understanding molecular mechanism in TC is necessary. In this research, we attempted to search the underlying molecular mechanism in TC.

Methods

ZEB1-AS1 expression was analyzed via qRT-PCR analysis. CCK-8, colony formation, flow cytometry and TUNEL assays were used to evaluate TC cell growth. The interaction between miR-133a-3p and LPAR3, EGFR and ZEB1-AS1 was testified through using RNA pull down and luciferase reporter assays.

Results

LPAR3 and EGFR were expressed at high levels in TC tissues and cell lines. Besides, both LPAR3 and EGFR could promote TC cell growth. Later, miR-133a-3p was searched as an upstream gene of LPAR3 and EGFR, and LPAR3 could partially rescue the suppressive effect of miR-133a-3p overexpression on TC progression, whereas the co-transfection of LPAR3 and EGFR completely restored the inhibition. Next, ZEB1-AS1 was confirmed as a sponge of miR-133a-3p. ZEB1-AS1 has a negative correlation with miR-133a-3p and a positive association with LPAR3 and EGFR through ceRNA analysis. Importantly, ZEB1-AS1 boosted the proliferation and suppressed the apoptosis in TC cells. Through restoration assays, we discovered that ZEB1-AS1 regulated LPAR3 and EGFR expression to mediate TC cell proliferation and apoptosis by sponging miR-133a-3p. Further investigation also indicated the oncogenic role of ZEB1-AS1 by mediating PI3K/AKT/mTOR pathway.

Conclusions

ZEB1-AS1 could be an underlying biomarker in TC.

Overexpressed miR-122-5p Promotes Cell Viability, Proliferation, Migration And Glycolysis Of Renal Cancer By Negatively Regulating PKM2

Objective

Renal cancer is one of the most deadly urological malignancies. Currently, there is still a lack of effective treatment. Our purpose was to explore the mechanisms of miR-122-5p in renal cancer.

Methods

The expression levels of miR-122-5p and pyruvate kinase M2 (PKM2) in renal cancer cells were detected by RT-qPCR and Western blot analyses, respectively. Then, we measured the cell viability after knockdown of miR-122-5p and PKM2 using CCK-8 assay. Moreover, flow cytometry was used to investigate cell cycle and apoptosis of renal cancer cells. The cell migration of renal cancer cells transfected by miR-122-5p inhibitor and siPKM2 was then detected by wound healing assay. Furthermore, glucose consumption and lactate production were measured. Autophagy-related protein LCII/I was detected by Western blot.

Results

MiR-122-5p was upregulated in renal cancer cells compared to HK2 cells, especially in 786-O cells. We found that silencing miR-122-5p promoted PKM2 expression in 786-O cells. After transfection of siPKM2 or miR-122-5p inhibitor, the cell viability of 786-O cells was significantly reduced. Furthermore, the G1 phase of 786-O cells was significantly blocked, and the S phase was significantly increased. In addition, knockdown of miR-122-5p or PKM2 promoted renal cancer cell apoptosis and inhibited cell migration. Glucose consumption of 786-O cells was significantly increased after transfection by siPKM2. Silencing miR-122-5p significantly promoted the expression levels of LCII/I.

Conclusion

Our findings revealed that overexpressed miR-122-5p promotes renal cancer cell viability, proliferation, migration, glycolysis and autophagy by negatively regulating PKM2, which provide a new insight for the development of renal cancer therapy.

MicroRNA Regulation of the Autotaxin-Lysophosphatidic Acid Signaling Axis

The revelation that microRNAs (miRNAs) exist within the human genome uncovered an underappreciated mechanism of gene expression. For cells to regulate expression of their genes, miRNA molecules and argonaute proteins bind to mRNAs and interfere with efficient translation of the RNA transcript. Although miRNAs have important roles in normal tissues, miRNAs may adopt aberrant functions in malignant cells depending on their classification as either a tumor suppressor or oncogenic miRNA. Within this review, the current status of miRNA regulation is described in the context of signaling through the lysophosphatidic acid receptors, including the lysophosphatidic acid-producing enzyme, autotaxin. Thus far, research has revealed miRNAs that increase in response to lysophosphatidic acid stimulation, such as miR-21, miR-30c-2-3p, and miR-122. Other miRNAs inhibit the translation of lysophosphatidic acid receptors, such as miR-15b, miR-23a, and miR200c, or proteins that are downstream of lysophosphatidic acid signaling, such as miR-146 and miR-21. With thousands of miRNAs still uncharacterized, it is anticipated that the complex regulation of lysophosphatidic acid signaling by miRNAs will continue to be elucidated. RNA-based therapeutics have entered the clinic with enormous potential in precision medicine. This exciting field is rapidly emerging and it will be fascinating to witness its expansion in scope.

MicroRNA heterogeneity in melanoma progression

The altered expression of miRNAs has been linked with neocarcinogenesis or the development of human malignancies including melanoma. Of significance, multiple clinical studies have documented that distinct sets of microRNAs (miRNAs) could be utilized as prognostic biomarkers for cancer development or predict the outcomes of treatment responses. To that end, an in-depth validation of such differentially expressed miRNAs is necessary in diverse settings of cancer patients in order to devise novel approaches to control tumor growth and/or enhance the efficacy of clinically-relevant therapeutic options. Moreover, considering the heterogeneity and sophisticated regulation of miRNAs, the precise delineation of their cellular targets could also be explored to design personalized medicine. Given the significance of miRNAs in regulating several key cellular processes of tumor cells including cell cycle progression and apoptosis, we review the findings of such miRNAs implicated in melanoma tumorigenesis. Understanding the novel mechanistic insights of such miRNAs will be useful for developing diagnostic or prognostic biomarkers or devising future therapeutic intervention for malignant melanoma.