Expression levels and co‑targets of miRNA‑126‑3p and miRNA‑126‑5p in lung adenocarcinoma tissues: Αn exploration with RT‑qPCR, microarray and bioinformatic analyses

MiR-1976/NCAPH/P65 axis inhibits the malignant phenotypes of lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a malignancy with an abysmal survival rate. High metastasis is the leading cause of the low survival rate of LUAD. NCAPH, an oncogene, is involved in the carcinogenesis of LUAD. However, the regulation of NCAPH in LUAD remains controversial. In this work, we identified an up-regulation of NCAPH in LUAD tissues. Patients who expressed more NCAPH had shorter overall survival (OS). Furthermore, NCAPH overexpression promoted LUAD cell migration while inhibiting apoptosis. MiR-1976 and miR-133b were predicted to target NCAPH expression by searching TargetScan and linkedomics databases. Following that, we confirmed that miR-1976 suppressed NCAPH by directly targeting a 7-bp region of NCAPH 3' untranslated regions (UTR). In addition, increased expression of miR-1976 decreased the proliferation & migration and promoted apoptosis of LUAD cells, and the re-introduction of NCAPH reversed these influences. Furthermore, the xenograft and metastasis mouse models also confirmed that miR-1976 inhibited tumor growth and metastasis in vivo by targeting NCAPH. Finally, we found that MiR-1976 targeting NCAPH blocked the activation of NF-κB. In conclusion, miR-1976 inhibits NCAPH activity in LUAD and acts as a tumor suppressor. The miR-1976/NCAPH/NF-κB axis may, in the future, represent crucial diagnostic and prognostic biomarkers and promising therapeutic options.

MicroRNA-126 selected with broad-spectrum analysis of microRNAs - a new predictive factor for the effectiveness of immunotherapy or chemoimmunotherapy in advanced NSCLC patients?

Introduction

Expression of PD-L1 on cancer cells is the only validated predictive factor for immunotherapy in NSCLC (Non-Small Cell Lung Cancer) patients. However, on this basis, it is difficult to predict the occurrence of resistance to immune checkpoint inhibitors (ICIs). MicroRNAs are widely studied as biomarkers of cancers. Our study was designed to determine whether microRNAs can be sensitive predictive factors in the qualification of NSCLC patients to first-line immunotherapy or chemoimmunotherapy.

Material and methods

The two-stage research on validation group (n=20) and study group (n=35) of patients with advanced NSCLC was conducted. Analysis of microRNAs expression by qPCR in plasma collected prior to the start of immunotherapy (pembrolizumab) or chemoimmunotherapy (combination of pembrolizumab with chemotherapy) was made. Broad-spectrum analysis of microRNAs expression was used in the studied group. Three microRNAs selected in that group as important for the effectiveness of ICIs were then examined in the validation group.

Results

In the studied group, significantly higher expression of miRNA-126-3p, miR-144-3p and miR-146-5p was observed in patients with long PFS compared to those with short PFS. In the validation group, low miRNA-126 expression indicated lower median progression-free survival and overall survival (2.3 vs. 5.0 months and 5.2 vs 11.2, respectively). These patients had a significantly higher risk of progression (HR= 2.92, 95% CI: 1.01 to 8.40, p=0.04) and death (HR=3.64, 95% CI: 1.22 to 10.84, p=0.02).

Conclusion

Our study showed that the expression of miR-126 in blood plasma may be a predictive factor for the effectiveness of first-line immunotherapy or chemoimmunotherapy in advanced NSCLC patients.

The Role of Thyroid Hormone Synthesis Gene-Related miRNAs Profiling in Structural and Functional Changes of The Thyroid Gland Induced by Excess Iodine

At recent years, the impairment caused by iodine excess are paid more attention. However, there is still largely unknown about the exact mechanism induced by excessive iodine. MiRNAs have been found to act as biomarkers for a variety of diseases, whereas fewer studies focused on miRNAs related to a cluster of genes regulating thyroid hormone synthesis, such as NIS, Pendrin, TPO, MCT8, TSHR, TSHα, and TSHβ-related miRNAs in structural and functional changes of the thyroid gland induced by subchronic and chronic high iodine exposure. In the present study, one hundred and twenty 4-week-old female Wistar rats were randomly divided into control group (I50µg/L KIO3); HI 1 (I6000µg/L KIO3); HI 2 (I10000µg/L KIO3); and HI 3 (I50000µg/L KIO3), the exposure period was 3 months and 6 months, respectively. The iodine contents in the urine and blood, thyroid function, and pathological changes were determined. In addition, levels of thyroid hormone synthesis genes and the associated miRNAs profiling were detected. The results showed that subclinical hypothyroidism occurred in the high iodine groups with subchronic high iodine exposure, while 6-month exposure led to hypothyroidism in the I10000µg/L and I50000µg/L groups. Subchronic and chronic high iodine exposure caused mRNA and protein levels of NIS, TPO, and TSHR decreased significantly, and Pendrin expression increased significantly. In addition, MCT8 mRNA and protein levels are only remarkably decreased under the subchronic exposure. PCR results showed that levels of miR-200b-3p, miR-185-5p, miR-24-3p, miR-200a-3p, and miR-25-3p increased significantly exposed to high iodine for 3 months, while miR-675-5p, miR-883-5p, and miR-300-3p levels increased significantly under the exposure to high iodine for 6 months. In addition, miR-1839-3p level was markedly decreased exposed to high iodine for 3 and 6 months. Taken together, the miRNA profiling of genes regulating thyroid hormone synthesis remarkably altered from subclinical hypothyroidism to hypothyroidism induced by excess iodine exposure, and some miRNAs may play an important role in subclinical hypothyroidism or hypothyroidism through regulating NIS, Pendrin, TPO, MCT8, and TSHR providing promising targets to alleviate the impairment on the structure and function of thyroid gland.

Potential upstream lncRNA-miRNA-mRNA regulatory network of the ferroptosis-related gene SLC7A11 in renal cell carcinoma

Background

SLC7A11 is a key regulator of ferroptosis, which mediates cysteine uptake for glutathione biosynthesis and maintains redox homeostasis. Emerging evidence has shown that SLC7A11 is upregulated in many human tumors. Nevertheless, the prognosis and posttranslational regulatory mechanism of SLC7A11 in renal cell carcinoma (RCC) remains obscure.

Methods

The Oncomine, Gene Expression Profiling Interactive Analysis (GEPIA), and The Cancer Genome Atlas (TCGA) databases were used to analyze the difference in SLC7A11 expression between malignant and normal tissues. Furthermore, the GEPIA, the University of ALabama at Birmingham CANcer data analysis Portal (UALCAN), and starBase databases were used to conduct the survival analyses. For correlation analysis, the UALCAN and starBase databases were employed. The Tumor Immune Estimation Resource (TIMER) database was used to approximate the abundance of immune infiltration.

Results

We confirmed that SLC7A11 was upregulated in most human cancers, including 3 types of RCC. SLC7A11 overexpression was linked to poor prognosis of individuals with kidney renal clear cell carcinoma (KIRC), kidney chromophobe cell carcinoma (KICH), and kidney renal papillary cell carcinoma (KIRP). SLC7A11 expression was also linked to immune cell infiltration levels. After performing a comprehensive analysis of the regulatory mechanisms of SLC7A11 expression, the results depicted a potential noncoding (ncRNA)-messenger RNA (mRNA) axis, incorporating SNHG6-miR-26a-5p-SLC7A11 networks in KICH, CASC19/CYTOR/LINC00997-miR-27b-3pSLC7A11 networks in KIRC, and CASC19/CYTOR/PVT1-miR27b-3p-SLC7A11 networks in KIRP as partially responsible for the functions of SLC7A11 in RCC. SLC7A11 expression was positively linked to infiltrated immune cells and their matching marker sets in 3 types of RCC, including CD8⁺ and myeloid dendritic cells.

Conclusions

Our research elucidated the crucial functions and the upstream long noncoding RNA (lncRNA)-microRNA (miRNA) regulatory network of SLC7A11 in RCC. Importantly, SLC7A11 can be used as a potential prognostic biomarker for 3 types of RCC and to determine the infiltration of immune cells in malignant tissues.

MiR-27a-3p Promotes Non-Small Cell Lung Cancer Through SLC7A11-Mediated-Ferroptosis

Background

Ferroptosis is a newly generated regulatory cell death promoted by the accumulated lipid-based reactive oxygen species (ROS). Solute carrier family 7 member 11 (SLC7A11), the cystine/glutamate antiporter, is known as a ferroptosis executor that exhibits a positive correlation with carcinoma progression because of antioxidant function. Nonetheless, it is yet unclear on the understanding of ferroptosis regulation in lung cancer.

Methods

Database, qRT-PCR, Western-blot (WB), and immunohistochemistry were utilized to determine SLC7A11 expression and function, as well as gene iron related to necrosis in clinical tissue specimens and cells; a ferroptosis inducer, inhibitors, and SLC7A11 lentivirus were used to confirm SLC7A11's biological activity in cell viability, oxidative stress, lipid peroxidation, and iron ion enrichment in non-small cell lung cancer (NSCLC) in different cells; lentivirus was used to infect lung adenocarcinoma cell lines to acquire miR-27a-3p overexpression and knockdown cell lines, and to detect SLC7A11 level through qRT-PCR and WB. The influence of upregulated/downregulated miR-27a-3p on ferroptosis and other related biological characteristics of lung adenocarcinoma cell lines was detected.

Results

Upregulated SLC7A11 was shown in NSCLC patients and cells, and increased SLC7A11 had a relation to the poorly prognostic status of NSCLC patients. Besides, a novel miRNA, miR-27a-3p, was an essential modulator of ferroptosis via directly targeting SLC7A11 in NSCLC cells. Overexpressing miR-27a-3p led to SLC7A11 suppression via directly binding to its 3'-UTR, followed by the reduction of erastin-caused ferroptosis. In contrast, inhibited miR-27a-3p resulted in an increase in NSCLC cells' sensitivity to erastin. Of importance, the accumulated lipid ROS and cell death of iron peptide mediated by anti-miR-27a-3p can be eliminated by impeding the glutamylation process. Our literature collectively uncovered that miR-27a-3p modulated ferroptosis by targeting SLC7A11 in NSCLC cells, illustrating the important role of miRNA in ferroptosis.

Conclusion

MiR-27a-3p modulates ferroptosis via targeting SLC7A11 in NSCLC cells, implying the significant role of miR-27a-3p/SLC7A11 in ferroptosis.

The Indication of Poor Prognosis by High Expression of ENO1 in Squamous Cell Carcinoma of the Lung

The purpose of this study is to investigate the significance of alpha-enolase (ENO1) expression in squamous cell carcinoma of the lung (LUSC), its prognostic value, and prospective molecular mechanism. Using multiplatforms data, including in-house immunohistochemistry, in-house real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), in-house microarray, and public high-throughput data, the expression significance and prognostic role of ENO1 in LUSC tissues were analyzed comprehensively. With the combination of all eligible cases, compared with 941 non-LUSC lung tissues, ENO1 was significantly overexpressed in 1163 cases of LUSC (standardized mean difference (SMD) = 1.23, 95% confidence interval (CI) = 0.76–1.70, P < 0.001). ENO1 also displayed a great ability to differentiate LUSC tissues from non-LUSC lung tissues (AUC = 0.8705) with the comprehensive sensitivity being 0.88 [0.83–0.92], and comprehensive specificity being 0.89 [0.84–0.94]). Moreover, in 1860 cases of LUSC with survival information, patients with higher expression of ENO1 had poorer prognosis (hazard ratio (HR) = 1.20, 95% CI = 1.01–1.43, P = 0.043). ENO1 and its related genes mainly participated in the pathways of cell division and proliferation. In conclusion, the upregulation of ENO1 could affect the carcinogenesis and unfavorable outcome of LUSC.

Comprehensive analysis of PLOD family members in low-grade gliomas using bioinformatics methods

Low-grade gliomas (LGGs) is a primary invasive brain tumor that grows slowly but is incurable and eventually develops into high malignant glioma. Novel biomarkers for the tumorigenesis and lifetime of LGG are critically demanded to be investigated. In this study, the expression levels of procollagen-lysine, 2-oxoglutarate 5-dioxygenases (PLODs) were analyzed by ONCOMINE, HPA and GEPIA. The GEPIA online platform was applied to evaluate the interrelation between PLODs and survival index in LGG. Furthermore, functions of PLODs and co-expression genes were inspected by the DAVID. Moreover, we used TIMER, cBioportal, GeneMINIA and NetworkAnalyst analysis to reveal the mechanism of PLODs in LGG. We found that expression levels of each PLOD family members were up-regulated in patients with LGG. Higher expression of PLODs was closely related to shorter disease-free survival (DFS) and overall survival (OS). The findings showed that LGG cases with or without alterations were significantly correlated with the OS and DFS. The mechanism of PLODs in LGG may be involved in response to hypoxia, oxidoreductase activity, Lysine degradation and immune cell infiltration. In general, this research has investigated the values of PLODs in LGG, which could serve as biomarkers for diagnosis, prognosis and potential therapeutic targets of LGG patients.

Linc00426 accelerates lung adenocarcinoma progression by regulating miR-455-5p as a molecular sponge

Increasing lines of evidence indicate the role of long non-coding RNAs (LncRNAs) in gene regulation and tumor development. Hence, it is important to elucidate the mechanisms of LncRNAs underlying the proliferation, metastasis, and invasion of lung adenocarcinoma (LUAD). We employed microarrays to screen LncRNAs in LUAD tissues with and without lymph node metastasis and revealed their effects on LUAD. Among them, Linc00426 was selected for further exploration in its expression, the biological significance, and the underlying molecular mechanisms. Linc00426 exhibits ectopic expression in LUAD tissues and cells. The ectopic expression has been clinically linked to tumor size, lymphatic metastasis, and tumor differentiation of patients with LUAD. The deregulation of Linc00426 contributes to a notable impairment in proliferation, invasion, metastasis, and epithelial–mesenchymal transition (EMT) in vitro and in vivo. Mechanistically, the deregulation of Linc00426 could reduce cytoskeleton rearrangement and matrix metalloproteinase expression. Meanwhile, decreasing the level of Linc00426 or increasing miR-455-5p could down-regulate the level of UBE2V1. Thus, Linc00426 may act as a competing endogenous RNA (ceRNA) to abate miR-455-5p-dependent UBE2V1 reduction. We conclude that Linc00426 accelerates LUAD progression by acting as a molecular sponge to regulate miR-455-5p, and may be a potential novel tumor marker for LUAD.

MicroRNA-126: A new and promising player in lung cancer

Lung cancer is one of the most common malignant tumors associated with cancer death; however, the mechanisms involved in lung tumor development have not been completely elucidated, which impedes the advancement of clinical diagnosis and therapy. MicroRNA-126 (miR-126) is an important member of the microRNA family and is encoded by intron 7 of epidermal growth factor-like domain-containing gene 7. Increasing evidence has demonstrated that miR-126, as a distinct endothelial-enriched miRNA and new tumor suppressor gene, serves a promising role in the occurrence, development and metastasis of various types of cancer, including liver cancer, colorectal cancer, melanoma and lung cancer. In the present review, the current knowledge of the role of miR-126 in lung cancer growth, metastasis, diagnosis and prognosis as well as therapy was summarized, which may provide new insights on the biological roles of miRNAsin lung cancer and facilitate the ultimate development of miRNA-based therapies in clinical patients with non-small cell lung cancer.

SLC7A11/xCT in cancer: biological functions and therapeutic implications

Amino acid transporters mediate substrates across cellular membranes and their fine-tuned regulations are critical to cellular metabolism, growth, and death. As the functional component of system Xc-, which imports extracellular cystine with intracellular glutamate release at a ratio of 1:1, SLC7A11 has diverse functional roles in regulating many pathophysiological processes such as cellular redox homeostasis, ferroptosis, and drug resistance in cancer. Notably, accumulated evidence demonstrated that SLC7A11 is overexpressed in many types of cancers and is associated with patients' poor prognosis. As a result, SLC7A11 becomes a new potential target for cancer therapy. In this review, we first briefly introduce the structure and function of SLC7A11, then discuss its pathological role in cancer. We next summarize current available data of how SLC7A11 is subjected to fine regulations at multiple levels. We further describe the potential inhibitors of the SLC7A11 and their roles in human cancer cells. Finally, we propose novel insights for future perspectives on the modulation of SLC7A11, as well as possible targeted strategies for SLC7A11-based anti-cancer therapies.

Characterization of a non-coding RNA-associated ceRNA network in metastatic lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a highly malignant cancer. Although competing endogenous RNA (ceRNA)-based profiling has been investigated in patients with LUAD, it has not been specifically used to study metastasis in LUAD. We found 130 differentially expressed (DE) lncRNAs, 32 DE miRNAs and 981 DE mRNAs from patients with LUAD in The Cancer Genome Atlas (TCGA) database. We analysed the functions and pathways of 981 DE mRNAs using the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Based on the target DE mRNAs and DE lncRNAs of DE miRNAs, we established an lncRNA-miRNA-mRNA ceRNA network, comprising 37 DE lncRNAs, 22 DE miRNAs and 212 DE mRNAs. Subsequently, we constructed a protein-protein interaction network of DE mRNAs in the ceRNA network. Among all, DE RNAs, 5 DE lncRNAs, 5 DE miRNAs and 45 DE mRNAs were confirmed found to be associated with clinical prognosis. Moreover, 3 DE lncRNAs, 4 DE miRNAs and 9 DE mRNAs in the ceRNA network were associated with clinical prognosis. We further screened 3 DE lncRNAs, 3 DE miRNAs and 3 DE mRNAs using clinical samples. These DE lncRNAs, DE miRNAs and DE mRNAs in ceRNA network may serve as independent biomarkers of LUAD metastasis.

Downregulation of miRNA-126-3p is associated with progression of and poor prognosis for lung squamous cell carcinoma

Lung squamous cell carcinoma (LUSC) is the main pathological type of pulmonary malignant tumors; at present, less than 10% of patients with advanced metastatic LUSC live for more than 5 years. We previously reported that low expression of miRNA-126-3p is associated with the occurrence and progression of lung adenocarcinoma (LUAD). Here, we examined expression of miRNA-126-3p in 23 samples from patients with LUSCs and 23 normal control specimens by quantitative real-time PCR (RT-qPCR). Associations between miRNA-126-3p expression and clinical features were studied from materials derived from Gene Expression Omnibus (GEO) chips and The Cancer Genome Atlas (TCGA) database. Twelve online platforms were used to identify candidate target genes of miRNA-126-3p. Further analyses of the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and protein-protein interaction (PPI) network were performed on the target genes. GEO microarray analysis, TCGA data mining, RT-qPCR, and integration analysis consistently reported low expression of miRNA-126-3p in LUSC. A total of 42 genes were identified as potential target genes of miRNA-126-3p from online platforms, GEO microarrays, and the TCGA database. GO and KEGG analyses demonstrated that the target genes are involved in several biological processes that promote the progression of LUSC. SOX2, E2F2, and E2F3 were selected as hub genes from the PPI network for further analysis. In summary, our results suggest that the low expression of miRNA-126-3p may play a role in promoting the development of LUSC and miRNA-126-3p may be a biomarker for LUSC early diagnosis and prognosis.

MicroRNA in Lung Cancer Metastasis

Tumor metastasis is a hallmark of cancer, with distant metastasis frequently developing in lung cancer, even at initial diagnosis, resulting in poor prognosis and high mortality. However, available biomarkers cannot reliably predict cancer spreading sites. The metastatic cascade involves highly complicated processes including invasion, migration, angiogenesis, and epithelial-to-mesenchymal transition that are tightly controlled by various genetic expression modalities along with interaction between cancer cells and the extracellular matrix. In particular, microRNAs (miRNAs), a group of small non-coding RNAs, can influence the transcriptional and post-transcriptional processes, with dysregulation of miRNA expression contributing to the regulation of cancer metastasis. Nevertheless, although miRNA-targeted therapy is widely studied in vitro and in vivo, this strategy currently affords limited feasibility and a few miRNA-targeted therapies for lung cancer have entered into clinical trials to date. Advances in understanding the molecular mechanism of metastasis will thus provide additional potential targets for lung cancer treatment. This review discusses the current research related to the role of miRNAs in lung cancer invasion and metastasis, with a particular focus on the different metastatic lesions and potential miRNA-targeted treatments for lung cancer with the expectation that further exploration of miRNA-targeted therapy may establish a new spectrum of lung cancer treatments.