Identification of lncRNA-miRNA-mRNA Networks Linked to Non-small Lung Cancer Resistance to Inhibitors of Epidermal Growth Factor Receptor

Whole transcriptome landscape in HAPE under the stress of environment at high altitudes: new insights into the mechanisms of hypobaric hypoxia tolerance

Background

High altitude pulmonary edema (HAPE) is an idiopathic, noncardiogenic form of pulmonary edema that occurs at high altitudes. It is characterized by a severe clinical course and carries a significant mortality risk. Despite its clinical relevance, the molecular mechanisms underlying HAPE are not well understood.

Methods

We conducted whole-transcriptome RNA sequencing on blood samples from 6 pairs of HAPE patients and healthy controls to identify differentially expressed (DE) mRNAs, miRNAs, circRNAs, lncRNAs, along with alternative splicing (AS) events, gene fusions, and novel transcripts. To explore the regulatory dynamics, we constructed ceRNA networks and analyzed immune cell infiltration patterns, further annotating the biological functions of these transcripts. For empirical validation, we selected five circRNAs from the ceRNA network and conducted RT-qPCR on 50 paired samples. Additionally, we assessed the correlations between circRNA expression levels and clinical data to evaluate their diagnostic potential.

Results

We observed 2,023 differentially expressed mRNAs (DEmRNAs), 84 DEmiRNAs, 200 DEcircRNAs, and 3,573 DElncRNAs. A total of 139 'A3SS' events, 103 'A5SS' events, 545 'MXE' events, 14 'RI' events, and 1,482 'SE' events were identified in the AS events analysis between the two groups. Two ceRNA networks were constructed. T cells, follicular helper, and Macrophages M1 cells exhibited the strongest positive correlation (R=0.82), while naive B cells and memory B cells demonstrated the strongest negative correlation (R=-0.62). In total, the expression of three circRNAs was significantly different in a larger cohort. Hsa_circ_0058497, hsa_circ_0081006, and hsa_circ_0083220 demonstrated consistent with the RNA sequencing results. These three circRNAs strongly correlate with clinical indicators and exhibit potential as diagnostic biomarkers. Finally, we verified five genes (CXCR4, HSD17B2, ANGPTL4, TIMP3, N4BP3) that were differentially expressed in endothelial cells under normoxia and hypoxia through bioinformatics and RT-qPCR analyses.

Conclusion

This study elucidates the differential expression of coding and non-coding RNAs (ncRNAs) in HAPE, identifies new transcripts and genes, and enhances our understanding of the transcriptional characteristics of HAPE. Moreover, it highlights the potential role of circRNAs in advancing the diagnosis and treatment of HAPE.

Distinct roles of CD244 expression in cancer diagnosis and prognosis: A pan-cancer analysis

The abnormal expression of tumor associated genes in pan-cancer is closely related to the clinicopathological features of distinct cancer types. Thus, identifying the role of specific genes in pan-cancer is needed for developing effective anti-cancer strategies. However, the function of CD244 in pan-cancer has not been fully understood. In this study, we explored the CD244 expression profile across 33 tumor types based on The Cancer Genome Atlas project, the Gene Expression Omnibus database, and other bioinformatics tools. We found down-regulated expression levels in seven tumor types and up-regulated expression levels in two tumor types. We subsequently explored the relationship between survival rate and CD244 expression, and found the positive relationship in patients with adrenocortical carcinoma (ACC), head and neck squamous cell carcinoma (HNSC), skin cutaneous melanoma (SKCM), and uterine corpus endometrial carcinoma (UCEC). We further investigated the association between CD244 expression and tumor-infiltrating immune cells, and discovered their positive correlation in different tumors. We found that CD244 expression level was higher in normal samples than in UCEC samples, and was positively associated with CD8+ T cells infiltrating. The mutation status, promoter methylation, CD244-related molecules and signaling pathways were also employed to study the potential function of CD244 in tumor initiation and progression. Our study offers a comprehensive overview of CD244 in human tumors, revealing CD244 as a potential prognostic biomarker and immunotherapeutic target in cancers.

Long non-coding RNAs in non-small cell lung cancer: implications for EGFR-TKI resistance

Non-small cell lung cancer (NSCLC) is one of the most common types of malignant tumors as well as the leading cause of cancer-related deaths in the world. The application of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) has dramatically improved the prognosis of NSCLC patients who harbor EGFR mutations. However, despite an excellent initial response, NSCLC inevitably becomes resistant to EGFR-TKIs, leading to irreversible disease progression. Hence, it is of great significance to shed light on the molecular mechanisms underlying the EGFR-TKI resistance in NSCLC. Long non-coding RNAs (lncRNAs) are critical gene modulators that are able to act as oncogenes or tumor suppressors that modulate tumorigenesis, invasion, and metastasis. Recently, extensive evidence demonstrates that lncRNAs also have a significant function in modulating EGFR-TKI resistance in NSCLC. In this review, we present a comprehensive summary of the lncRNAs involved in EGFR-TKI resistance in NSCLC and focus on their detailed mechanisms of action, including activation of alternative bypass signaling pathways, phenotypic transformation, intercellular communication in the tumor microenvironment, competing endogenous RNAs (ceRNAs) networks, and epigenetic modifications. In addition, we briefly discuss the limitations and the clinical implications of current lncRNAs research in this field.

Panel of miR-150 and linc00673, regulators of CCR6/CCL20 may serve as non-invasive diagnostic marker of non-small cell lung cancer

The C-C motif ligand 20 (CCL20) is a chemokine that specifically binds to the chemokine receptor 6 (CCR6) and the CCL20/CCR6 axis has been implicated in the non-small lung cancer (NSCLC) development and progression. Its expression is regulated by mutual interactions of non-coding RNAs (ncRNAs). This goals of presented study was to evaluate the expression level of CCR6/CCL20 mRNA in NSCLC tissue comparative to selected ncRNAs: miR-150, linc00673. The expression level of the studied ncRNAs was also assessed in serum extracellular vesicles (EVs). Thirty patients (n = 30) were enrolled as the study cohort. Total RNA was isolated from tumor tissue, adjacent macroscopically unchanged tissue and serum EVs. The expression level of studied genes and ncRNAs were estimated based on the qPCR method. Higher expression level of CCL20 mRNA but lower expression level of CCR6 mRNA were observed in tumor in comparison to control tissue. Relative to the smoking status, higher CCL20 (p < 0.05) and CCR6 mRNA (p > 0.05) expression levels were observed in current smokers than in never smokers. In serum EVs the expression level of miR-150 has a negative correlation with AJCC tumor staging, whereas the expression level of linc00673 positively correlated (p > 0.05). The lower expression level of miR-150 and higher expression level of linc00673 in serum EVs were observed in NSCLC patients with lymph nodes metastases (p > 0.05). Regarding the histopathological type, significantly lower expression level of miR-150 and higher expression level of linc00673 were observed in the serum EVs of patients with AC compared to patient with SCC. Our findings revealed that smoking significantly changed the expression level of CCL20 mRNA in NSCLC tissue. Changes in expression levels of miR-150 and linc00673 in the serum EVs of NSCLC patients in relation to presence of lymph node metastases and the stage of cancer development may serve as a non-invasive molecular biomarkers of tumor progression. Furthermore, expression levels of miR-150 and linc00673 may serve as non-intrusive diagnostic biomarkers differentiating adenocarcinoma from squamous cell carcinoma.

Analysis of the lncRNA-miRNA-mRNA Network Reveals a Potential Regulatory Mechanism of EGFR-TKI Resistance in NSCLC

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are widely used for patients with EGFR-mutated lung cancer. Despite its initial therapeutic efficacy, most patients eventually develop drug resistance, which leads to a poor prognosis in lung cancer patients. Previous investigations have proved that non-coding RNAs including long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs) contribute to drug resistance by various biological functions, whereas how they regulate EGFR-TKI resistance remains unclear. In this study, we examined gene expression using the microarray technology on gefitinib-resistant NSCLC cells to obtain differentially expressed (DE) lncRNAs and mRNAs. A total of 45 DE-lncRNAs associated with overall survival and 1799 target DE-mRNAs were employed to construct a core lncRNA-miRNA-mRNA network to illustrate underlying molecular mechanisms of how EGFR-TKI resistance occurs in NSCLC. We found that target DE-mRNAs were mainly enriched in pathways involved in EGFR-TKI resistance, especially the target DE-mRNAs regulated by LINC01128 were significantly enriched in the PI3K/Akt signaling pathway, where the synergy of these target DE-mRNAs may play a key role in EGFR-TKI resistance. In addition, downregulated LINC01128, acting as a specific miRNA sponge, decreases PTEN via sponging miR-25-3p. Furthermore, signaling reactions caused by the downregulation of PTEN would activate the PI3K/Akt signaling pathway, which may lead to EGFR-TKI resistance. In addition, a survival analysis indicated the low expression of LINC01128, and PTEN is closely related to poor prognosis in lung adenocarcinoma (LUAD). Therefore, the LINC01128/miR-25-3p/PTEN axis may promote EGFR-TKI resistance via the PI3K/Akt signaling pathway, which provides new insights into the underlying molecular mechanisms of drug resistance to EGFR-TKIs in NSCLC. In addition, our study sheds light on developing novel therapeutic approaches to overcome EGFR-TKI resistance in NSCLC.

High Expression of lncRNA HEIH is Helpful in the Diagnosis of Non-Small Cell Lung Cancer and Predicts Poor Prognosis

Background

This study aims to investigate the expression and clinical value of long non-coding RNA (lncRNA) HEIH in peripheral blood of patients with non-small cell lung cancer (NSCLC).

Methods

Healthy subjects (N=70), patients with lung squamous cell carcinoma (LUSC, N=70) and patients with lung adenocarcinoma (LUAD, N=80) were included. LncRNA HEIH expression in peripheral blood of included subjects was detected using RT-qPCR. According to the median expression of lncRNA HEIH, LUSC and LUAD patients were allocated into lncRNA HEIH high/low expression groups. The correlation between lncRNA HEIH and clinical indicators of patients was analyzed; Logistic multifactor regression was used to analyze the independent risk factors influencing lncRNA HEIH level. Receiver-operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of lncRNA HEIH and carcinoembryonic antigen (CEA) in LUSC/LUAD patients. MedCalc-Comparison of ROC curves was used to compare the area under ROC curve. The cumulative survival rates of lncRNA HEIH high/low expression group were analyzed by Kaplan–Meier curve. COX multivariate analysis was used to assess the independent factors affecting prognosis of NSCLC.

Results

LncRNA HEIH in peripheral blood of LUSC/LUAD patients was higher than that in healthy controls, with no evident difference between LUSC and LUAD groups. In LUSC/LUAD patients, TNM stage, lymph node metastasis, distal metastasis, and CEA were independent risk factors affecting lncRNA HEIH; patients with high lncRNA HEIH expression had larger pack-years and tumor size, higher CEA level and tumor stage, and higher risk of lymph node metastasis and distal metastasis. LncRNA HEIH had higher diagnostic efficiency than CEA in NSCLC patients. High expression of lncRNA HEIH predicted poor prognosis in patients with NSCLC and was an independent risk factor for prognosis of NSCLC.

Conclusion

High expression of lncRNA HEIH is helpful in the diagnosis of NSCLC and predicts poor prognosis.