Long non-coding RNAs in non-small cell lung cancer as biomarkers and therapeutic targets

Comprehensive review for non-coding RNAs: From mechanisms to therapeutic applications

Non-coding RNAs (ncRNAs) are an assorted collection of transcripts that are not translated into proteins. Since their discovery, ncRNAs have gained prominence as crucial regulators of various biological functions across diverse cell types and tissues, and their abnormal functioning has been implicated in disease. Notably, extensive research has focused on the relationship between microRNAs (miRNAs) and human cancers, although other types of ncRNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), are also emerging as significant contributors to human disease. In this review, we provide a comprehensive summary of our current knowledge regarding the roles of miRNAs, lncRNAs, and circRNAs in cancer and other major human diseases, particularly cancer, cardiovascular, neurological, and infectious diseases. Moreover, we discuss the potential utilization of ncRNAs as disease biomarkers and as targets for therapeutic interventions.

Modulation of long noncoding RNAs by polyphenols as a novel potential therapeutic approach in lung cancer: A comprehensive review

Lung cancer stands as a formidable global health challenge, necessitating innovative therapeutic strategies. Polyphenols, bioactive compounds synthesized by plants, have garnered attention for their diverse health benefits, particularly in combating various cancers, including lung cancer. The advent of whole-genome and transcriptome sequencing technologies has illuminated the pivotal roles of long noncoding RNAs (lncRNAs), operating at epigenetic, transcriptional, and posttranscriptional levels, in cancer progression. This review comprehensively explores the impact of polyphenols on both oncogenic and tumor-suppressive lncRNAs in lung cancer, elucidating on their intricate regulatory mechanisms. The comprehensive examination extends to the potential synergies when combining polyphenols with conventional treatments like chemotherapy, radiation, and immunotherapy. Recognizing the heterogeneity of lung cancer subtypes, the review emphasizes the need for the integration of nanotechnology for optimized polyphenol delivery and personalized therapeutic approaches. In conclusion, we collect the latest research, offering a holistic overview of the evolving landscape of polyphenol-mediated modulation of lncRNAs in lung cancer therapy. The integration of polyphenols and lncRNAs into multidimensional treatment strategies holds promise for enhancing therapeutic efficacy and navigating the challenges associated with lung cancer treatment.

CircBRIP1: a plasma diagnostic marker for non-small-cell lung cancer

BACKGROUND

Circular RNA (circRNA), which has been demonstrated in studies to be abundantly prevalent in tumor cells and bodily fluids and to play a significant role in tumors, has the potential for biological markers to be used to assist tumor diagnosis. This study mainly discusses the potential of circBRIP1 as a biomarker for diagnosing non-small-cell lung cancer (NSCLC).

METHODS

First, high-throughput sequencing screened the differentially expressed circBRIP1, and real-time fluorescence quantitative PCR (qRT-PCR) verified its expression in NSCLC. Next, sanger sequencing, agarose gel electrophoresis, RNase R assay, and fluorescence in situ hybridization (FISH) were used to verify its molecular characteristics. The diagnostic value was analyzed by the subject operating characteristic curve (ROC), and the cardinality test was analyzed for correlation with clinicopathological parameters. Finally, we tentatively predicted the downstream miRNA- or RNA-binding protein that may bind to circBRIP1.

RESULTS

CircBRIP1 is highly expressed in NSCLC tissues, cells and plasma with good specificity and stability. CircBRIP1 not only can well-distinguish NSCLC patients from benign pulmonary diseases (BPD) patients, healthy individuals and small cell lung cancer (SCLC) patients, but it also has some potential for dynamic monitoring. Combined with the analysis of clinicopathological data, the high level of circRNA expression was related to the degree of tumor differentiation, TNM stage, T stage, lymph node metastasis and distal metastasis in NSCLC patients. In addition, circBRIP1 has a high diagnostic value.

CONCLUSIONS

Plasma circBRIP1 is significantly overexpressed in NSCLC patients. It can be used as a sensitive biomarker with unique value for early diagnosis, tumor development and prognosis detection.

The Role of Long Noncoding RNAs in Progression of Leukemia: Based on Chromosomal Location

Long non-coding RNA [LncRNA] dysregulation has been seen in many human cancers, including several kinds of leukemia, which is still a fatal disease with a poor prognosis. LncRNAs have been demonstrated to function as tumor suppressors or oncogenes in leukemia. This study covers current research findings on the role of lncRNAs in the prognosis and diagnosis of leukemia. Based on recent results, several lncRNAs are emerging as biomarkers for the prognosis, diagnosis, and even treatment outcome prediction of leukemia and have been shown to play critical roles in controlling leukemia cell activities, such as proliferation, cell death, metastasis, and drug resistance. As a result, lncRNA profiles may have superior predictive and diagnostic potential in leukemia. Accordingly, this review concentrates on the significance of lncRNAs in leukemia progression based on their chromosomal position.

Construction of 11 metabolic-related lncRNAs to predict the prognosis in lung adenocarcinoma

OBJECTIVE

To explore the metabolism-related lncRNAs in the tumorigenesis of lung adenocarcinoma.

METHODS

The transcriptome data and clinical information about lung adenocarcinoma patients were acquired in TCGA (The Cancer Genome Atlas). Metabolism-related genes were from the GSEA (Gene Set Enrichment Analysis) database. Through differential expression analysis and Pearson correlation analysis, lncRNAs about lung adenocarcinoma metabolism were identified. The samples were separated into the training and validation sets in the proportion of 2:1. The prognostic lncRNAs were determined by univariate Cox regression analysis and LASSO (Least absolute shrinkage and selection operator) regression. A risk model was built using Multivariate Cox regression analysis, evaluated by the internal validation data. The model prediction ability was assessed by subgroup analysis. The Nomogram was constructed by combining clinical indicators with independent prognostic significance and risk scores. C-index, calibration curve, DCA (Decision Curve Analysis) clinical decision and ROC (Receiver Operating Characteristic Curve) curves were obtained to assess the prediction ability of the model. Based on the CIBERSORT analysis, the correlation between lncRNAs and tumor infiltrating lymphocytes was obtained.

RESULTS

From 497 lung adenocarcinoma and 54 paracancerous samples, 233 metabolic-related and 11 prognostic-related lncRNAs were further screened. According to the findings of the survival study, the low-risk group had a greater OS (Overall survival) than the high-risk group. ROC analysis indicated AUC (Area Under Curve) value was 0.726. Then, a nomogram with T, N stage and risk ratings was developed according to COX regression analysis. The C-index was 0.743, and the AUC values of 3- and 5-year survival were 0.741 and 0.775, respectively. The above results suggested the nomogram had a good prediction ability. The results based on the CIBERSORT algorithm demonstrated the lncRNAs used to construct the model had a strong correlation with the polarization of immune cells.

CONCLUSIONS

The study identified 11 metabolic-related lncRNAs for lung adenocarcinoma prognosis, on which basis a prognostic risk scoring model was created. This model may have a good predictive potential for lung adenocarcinoma.

IL-18 serves as a main effector of CAF-derived METTL3 against immunosuppression of NSCLC via driving NF-κB pathway

Background: N6-methyladenosine (m6A) is the most abundant modification in eukaryotic mRNA. However, its role in non-small cell lung cancer (NSCLC) has not been completely elucidated.Objective: To explore whether methyltransferase like 3 (METTL3) in cancer associated fibroblasts (CAFs) affects the secretion of IL-18, which drives NSCLC cells to regulate PD-L1-mediated immunosuppression via the nuclear factor kappa B (NF-κB) pathway.Methods: Histopathological features of NSCLC tissues were identified by H&E and IHC staining. The levels of m6A writers (METTL3), IL-18 and NF-κB pathway related genes were assessed. The quantity of CD8+ T cells was evaluated by flow cytometry (FCM). The direct binding relationship between METTL3 and IL-18 mRNA was detected by RIP assay and RNA pulldown and confirmed by dual - luciferase reporter assay. The level of RNA m6A was detected by RNA m6A dot blot and meRIP assays. A heterotopic implantation model of NSCLC was established in NOD-SCID mice for further explore the effect of CAF derived METTL3 on immunosuppression of NSCLC in vivo.Results: Our results illustrated that METTL3 was down-regulated in CAFs, and CAF derived METTL3 alleviated PD-L1-mediated immunosuppression of NSCLC through IL-18. Subsequently, we found that IL-18 was main effector of CAF-derived METTL3 against immunosuppression of NSCLC, and IL-18 accelerated immunosuppression of NSCLC by driving NF-κB pathway. In vivo, METTL3 knockdown-derived CAFs accelerated immunosuppression of NSCLC.Conclusion: IL-18 served as a main effector of CAF-derived METTL3 against immunosuppression of NSCLC via driving NF-κB pathway.

Unraveling the prevalence of various signalling pathways in non-small-cell lung cancer: a review

Cancer has become a huge public health issue all around the world. The focus of research is on innovative cancer therapy techniques that include the disease's unique targets. Among the cancer-related deaths that occur, lung cancer is considered to be one of the major, accounting for about 1.6 million fatalities globally in 2012, or nearly 20% of all cancer deaths. Non-small-cell lung cancer, a type of lung cancer comprises upto 84% of lung cancer cases, demonstrating the need for a more effective treatment. A novel category of cancer management, known as targeted cancer medicines, has risen to prominence in recent years. Targeted cancer treatments, like traditional chemotherapy, employ pharmacological drugs to slow cancer development, enhance cell death, and prevent it from spreading. Targeted treatments, as the name implies, work by interfering with particular proteins implicated in cancer. Numerous research conducted in the last several decades have led to the conclusion that signalling pathways are involved in the growth of lung cancer. All malignant tumours are produced, spread, invade, and behave in various abnormal ways due to abnormal pathways. Numerous significant signalling pathways, including the RTK/RAS/MAP-Kinase pathway (hence often referred to as RTK-RAS for simplicity), PI3K/Akt signalling, and others, have been discovered as commonly genetically changed. The current developments in research on various signalling pathways, as well as the underlying mechanisms of the molecules implicated in these pathways, are innovatively summarised in this review. To give a good sense of the study that has been done so far, many routes are placed together. Thus, this review includes the detailed description regarding each pathways, the mutations formed, and the present treatment strategy to overcome the resistance.

Development of clinical trials for non-small cell lung cancer drugs in China from 2005 to 2023

Objective

Over the past few decades, the development of anti-cancer drugs in China has made outstanding achievements based on the support of national policies. To assess the progress of non-small cell lung cancer (NSCLC) drugs, we conducted a statistical analysis of clinical trials of drugs targeting NSCLC in China from 2005 to 2023.

Methods

We downloaded, screened and analysed the data from three official websites, the Centre for Drug Evaluation of China National Medical Products Administration website (NMPA), ClinicalTrials.gov and the Chinese Clinical Trial Registry (ChiCTR).

Results

From January 1, 2005 to April 15, 2023, a total of 1,357 drug clinical trials that met the standards were included, and the number of registered drug clinical trials has been increasing year by year, reaching the maximum of 199 in 2021. Among them, the maximum of 462 items (34.05%) in phase II clinical trials, followed by 333 (24.54%) in phase III clinical trials, and 139 (10.24%) in phase IV clinical trials. In all drug clinical trials, industry sponsored trials (ISTs) have 722 items (53.21%), which are higher than investigator-initiated trials (IITs). The clinical trials of chemical drugs have a maximum of 723 items (53.28%), while biopharmaceuticals have grown rapidly in the past 10 years, with a total of 374 (27.56%), and 48.19% of the drug clinical trials of combined medication. In addition, the geographical distribution of the leading units and participating units of Chinese drug clinical trials are uneven, and economic regions such as Beijing, Shanghai, Jiangsu are obviously ahead of other regions.

Conclusion

From 2005 to 2023, the clinical trials of registered drugs for the treatment of NSCLC increased rapidly. Among them, due to the development of immunotherapy, the clinical trials of biopharmaceuticals and drugs for combined medication are growing most rapidly, while the exploration of the original drugs is a little far from enough. Our research provides a direction for the future drug clinical trials of NSCLC, laying foundation for further extending the survival rate of patients with NSCLC.

Long intergenic non-protein-coding RNA 1547 acts as a competing endogenous RNA and exerts cancer-promoting activity in non-small cell lung cancer by targeting the microRNA-195-5p/ homeobox C8 axis

Long intergenic non-protein coding RNA 1547 (LINC01547) presents a notable relationship with prognosis in patients with ovarian cancer. Herein, we examined the expression of LINC01547 in non-small cell lung cancer (NSCLC) to ascertain its clinical significance. We also explored the detailed functions of LINC01547 in regulating the aggressive phenotype of NSCLC and the molecular mechanism of action underlying its carcinogenic activities events in NSCLC. Furthermore, we applied the data acquired from the tissue specimens and the Cancer Genome Atlas (TCGA) database to analyze the level of LINC01547 in NSCLC and conducted functional assays to address the regulatory effect of LINC01547. Further, we examined the mechanistic interaction among LINC01547, microRNA-195-5p (miR-195-5p), and homeobox C8 (HOXC8) using bioinformatics prediction and luciferase reporter assay. LINC01547 was noticeably overexpressed, as affirmed by data from TCGA and our own cohort; moreover, poor prognosis was associated with increased LINC01547 levels in patients with NSCLC. LINC01547 regulates cell proliferation, colony-forming, migration, and invasion, and its absence produced tumor-repressing effects in NSCLC. Mechanistically, as a competitive endogenous RNA, LINC01547 decoyed miR-195-5p and consequently resulted in the overexpression of HOXC8 in NSCLC cells. Using rescue experiments, we found that the regulatory activities of LINC01547 deficient in repressing the malignant properties of NSCLC cells could be counteracted by hindering miR-195-5p or overexpressing HOXC8. Conclusively, LINC01547 serves as a crucial component to worsen the oncogenicity of NSCLC cells by controlling the miR-195-5p/HOXC8 axis. Thus, the newly identified competing endogenous RNA pathway may potentially be an attractive therapeutic for NSCLC management.

LncRNA SLC9A3-AS1 knockdown increases the sensitivity of liver cancer cell to triptolide by regulating miR-449b-5p-mediated glycolysis

Triptolide (TP) is involved in the progression of liver cancer. However, the detailed molecular network regulated through TP is still unclear. Long non-coding RNA (LncRNA) SLC9A3 exerts roles in various pathological progresses. Nevertheless, whether SLC9A3 affects the sensitivity of liver cancer cells to TP have not been uncovered. The content of SLC9A3-AS1 and miR-449b-5p was estimated by utilizing quantitative real-time polymerase-chain reaction (qRT-PCR). Cell counting kit 8 (CCK-8) assay was introduced to assess cell viability. Additionally, cell viability as well as invasion was tested via transwell assay. The direct binding between miR-449b-5p and SLC9A3-AS1 or LDHA was confirmed through luciferase reporter gene assay. Moreover, glycolysis rate was tested by calculating the uptake of glucose in addition to the production of lactate in Huh7 cells. LncRNA SLC9A3-AS1 was up-regulated in liver cancer tissue samples and cells. Knockdown of SLC9A3-AS1 notably further inhibited viability, migration as well as invasion in Huh7 cells. MiR-449b-5p was the direct downstream miRNA of SLC9A3-AS1 and was down-regulated by SLC9A3-AS1 in Huh7 cells. In addition, miR-449b-5p was reduced in liver cancer tissues and cells. Overexpressed miR-449b-5p increased the sensitivity of Huh7 cells to TP remarkably. Moreover, miR-449b-5p negatively regulated LDHA expression in Huh7 cells. This work proved that SLC9A3-AS1 increased the sensitivity of liver cancer cells to TP by regulating glycolysis rate mediated via miR-449b-5p/LDHA axis. These findings implied that TP is likely to be a potent agent for treating patients diagnosed with liver cancer.

Recent Developments and Challenges in Molecular-Targeted Therapy of Non-Small-Cell Lung Cancer

Treatment of lung cancer with conventional therapies, which include radiation, surgery, and chemotherapy results in multiple undesirable adverse or side effects. The major clinical challenge in developing new drug therapies for lung cancer is resistance, which involves mutations and disturbance in various signaling pathways. Molecular abnormalities related to epidermal growth factor receptor (EGFR), v-Raf murine sarcoma viral oncogene homolog B1 (B-RAF) Kirsten rat sarcoma virus (KRAS) mutations, translocation of the anaplastic lymphoma kinase (ALK) gene, mesenchymal-epithelial transition factor (MET) amplification have been studied to overcome the resistance and to develop new therapies for non-small cell lung cancer (NSCLC). But, inevitable development of resistance presents limits the clinical benefits of various new drugs. Here, we review current progress in the development of molecularly targeted therapies, concerning six clinical biomarkers: EGFR, ALK, MET, ROS-1, KRAS, and B-RAF for NSCLC treatment.

LncRNA BC promotes lung adenocarcinoma progression by modulating IMPAD1 alternative splicing

BACKGROUND

The therapeutic value of targeted therapies in patients with lung cancer is reduced when tumours acquire secondary resistance after an initial period of successful treatment. However, the molecular events behind the resistance to targeted therapies in lung cancer remain largely unknown.

AIMS

To discover the important role and mechanism of lncRNA BC in promoting tumor metastasis and influencing clinical prognosis of LUAD.

MATERIALS & METHODS

Microarrays were used to screen a comprehensive set of lncRNAs with differential expression profiles in lung cancer cells. The functional role and mechanism of lncRNA were further investigated by gain- and loss-of-function assays. RNA pull-down, protein assays, and mass spectrometry were used to identify proteins that interacted with lncRNA. TaqMan PCR was used to measure lncRNA in lung adenocarcinoma and adjacent nontumor tissues from 428 patients. The clinical significance of lncRNA identified was statistically confirmed in this cohort of patients.

RESULTS

In this study, we show that the long non-coding RNA BC009639 (BC) is involved in acquired resistance to EGFR-targeted therapies. Among the 235 long non-coding RNAs that were differentially expressed in lung cancer cell lines, with different metastatic potentials, BC promoted growth, invasion, metastasis, and resistance to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), both in vitro and in vivo. BC was highly expressed in 428 patients with lung adenocarcinoma (LUAD) and high BC expression correlated with reduced efficacy of EGFR-TKI therapy. To uncover the molecular mechanism of BC-mediated EGFR-TKI resistance in lung cancer, we screened and identified nucleolin and hnRNPK that interact with BC. BC formed the splicing complex with nucleolin and hnRNPK to facilitate the production of a non-protein-coding inositol monophosphatase domain containing 1 (IMPAD1) splice variant, instead of the protein-coding variant. The BC-mediated alternative splicing (AS) of IMPAD1 resulted in the induction of the epithelial-mesenchymal transition and resistance to EGFR-TKI in lung cancer. High BC expression correlated with clinical progress and poor survival among 402 patients with LUAD.

DISSCUSSION

Through alternative splicing, BC boosted the non-coding IMPAD1-203 transcript variant while suppressing the IMPAD1-201 variant. In order to control the processing of pre-mRNA, BC not only attracted RNA binding proteins (NCL, IGF2BP1) or splicing factors (hnRNPK), but also controlled the formation of the splicing-regulator complex by creating RNA-RNA-duplexes.

CONCLUSION

Our results reveal an important role for BC in mediating resistance to EGFR-targeted therapy in LUAD through IMPAD1 AS and in implication for the targeted therapy resistance.

TNF and HNRNPL Related Immunoregulatory Long non-coding RNA (THRIL) and long intergenic noncoding RNA-p21 (lincRNA-p21) as potential useful biomarkers for the diagnosis of tuberculosis

Early diagnosis is crucial in controlling tuberculosis globally and in developing countries with the emergence of drug-resistant Mycobacterium tuberculosis strains. Long non-coding RNAs (lncRNAs) are promising tuberculosis diagnostic biomarkers. Two lncRNA diagnostic markers, lncRNA THRIL and lincRNA-p21, were studied as tuberculosis diagnostic biomarkers. This cross-sectional study was conducted at the Center of Respiratory Diseases of LAQUINTINIE hospital and the National Veterinary Laboratory of Douala from December 2020 to August 2021. The ability of lncRNAs to distinguish between 19 healthy controls, 15 latent tuberculosis, and 21 active tuberculosis was estimated using quantitative polymerase chain reaction and Receiver Operating Characteristic curve analysis. Our analysis showed that lncRNA THRIL and lincRNA-p21 were significantly upregulated (P <0.05) in active and latent tuberculosis compared with healthy controls. LincRNA-p21 expression was significantly increased (P <0.05) in active tuberculosis compared with latent tuberculosis, whereas lncRNA THRIL was not significantly affected (P ≥0.05). Both lncRNA THRIL and lincRNA-p21 showed excellent performance in classifying latent tuberculosis and healthy controls (AUC = 92.86%). Furthermore, lncRNA THRIL was good at discriminating active tuberculosis from healthy controls (AUC = 89.79%), while lincRNA-p21 showed excellent discriminating performance (AUC = 100%). LncRNA THRIL was identified as a poor discriminator of latent tuberculosis from active tuberculosis (AUC = 64.28%), while lincRNA-p21 showed excellent diagnostic performance in this distinction (AUC = 92.86%). Our cross-sectional study suggests that lncRNA THRIL and lincRNA-p21 are promising tuberculosis diagnostic biomarkers that can differentiate between latent and active infection.

Noncoding RNA-mediated macrophage and cancer cell crosstalk in hepatocellular carcinoma

The tumor microenvironment (TME) is a well-recognized system that plays an essential role in tumor initiation, development, and progression. Intense intercellular communication between tumor cells and other cells (especially macrophages) occurs in the TME and is mediated by cell-to-cell contact and/or soluble messengers. Emerging evidence indicates that noncoding RNAs (ncRNAs) are critical regulators of the relationship between cells within the TME. In this review, we provide an update on the regulation of ncRNAs (primarily micro RNAs [miRNAs], long ncRNAs [lncRNAs], and circular RNAs [circRNAs]) in the crosstalk between macrophages and tumor cells in hepatocellular carcinoma (HCC). These ncRNAs are derived from macrophages or tumor cells and act as oncogenes or tumor suppressors, contributing to tumor progression not only by regulating the physiological and pathological processes of tumor cells but also by controlling macrophage infiltration, activation, polarization, and function. Herein, we also explore the options available for clinical therapeutic strategies targeting crosstalk-related ncRNAs to treat HCC. A better understanding of the relationship between macrophages and tumor cells mediated by ncRNAs will uncover new diagnostic biomarkers and pharmacological targets in cancer.

The minor allele of rs17427875 in long non-coding RNA-HOXA11-AS influences the prognosis of subarachnoid hemorrhage (SAH) via modulating miR-15a and STAT3 expression

Background: HOAX11-AS was reported to promote the progression of liver cancer via the signaling pathway of miR-15a-3p/STAT3. In this study, we investigated the effect of rs17427875 on the prognosis of subarachnoid hemorrhage (SAH) and its underlying molecular mechanisms.

Methods: 158 SAH patients were recruited and grouped according to their genotypes rs17427875. Peripheral blood and cerebrospinal fluid (CSF) samples were collected for subsequent analysis. Quantitative real-time PCR, luciferase assays, Western blot and ELISA were performed to analyze the correlations between the expression of lncRNA-HOXA11-AS, miR-15a, TNF-α and NF-κB.

Results: The survival rate was remarkably higher in SAH patients carrying the AA genotype of rs17427875 when compared with those carrying the AT genotype. The expression of miR-15a was significantly repressed in the peripheral blood and CSF of SAH patients carrying the AT allele when compared with that in patients carrying the AA allele. MiR-15a showed a remarkable efficacy in inhibiting the luciferase activity of wild type lncRNA-HOXA11-AS and STAT3 in THP-1 cells. P-HOXA11-AS-T showed a stronger ability to suppress the expression of miR-15a and activate the expression of STAT3, TNF-α and NF-κB in THP-1 cells when compared with P-HOXA11-AS-A.

Conclusions: The findings demonstrated that the presence of the minor allele of rs17427875 in lncRNA-HOXA11-AS could increase the expression level of lncRNA-HOXA11-AS, thus elevating the expression level of STAT3 via down-regulating miR-15a, and increased STAT3 expression could aggravate inflammation to cause poor prognosis of SAH. Therefore, the rs17427875 polymorphism can be used as a potential biomarker for the prognosis of SAH.

Regulatory pathways and drugs associated with ferroptosis in tumors

Ferroptosis is a type of cell death that depends on iron and reactive oxygen species (ROS). The accumulation of iron and lipid peroxidation primarily initiates oxidative membrane damage during ferroptosis. The core molecular mechanism of ferroptosis includes the regulation of oxidation and the balance between damage and antioxidant defense. Tumor cells usually contain a large amount of H₂O₂, and ferrous/iron ions will react with excessive H₂O₂ in cells to produce hydroxyl radicals and induce ferroptosis in tumor cells. Here, we reviewed the latest studies on the regulation of ferroptosis in tumor cells and introduced the tumor-related signaling pathways of ferroptosis. We paid particular attention to the role of noncoding RNA, nanomaterials, the role of drugs, and targeted treatment using ferroptosis drugs for mediating the ferroptosis process in tumor cells. Finally, we discussed the currently unresolved problems and future research directions for ferroptosis in tumor cells and the prospects of this emerging field. Therefore, we have attempted to provide a reference for further understanding of the pathogenesis of ferroptosis and proposed new targets for cancer treatment.

Long noncoding RNA regulatory factor X3- antisense RNA 1 promotes non-small cell lung cancer via the microRNA-577/signal transducer and activator of transcription 3 axis

Lung cancer is the most frequent malignancy, and non-small cell lung cancer (NSCLC) is its most common pathological type. Molecular targeted therapy has been testified to be effective in intervening in the occurrence and development of malignancies. This study investigates the effect of lncRNA Regulatory Factor X3- antisense RNA 1 (RFX3-AS1) in NSCLC progression. The RFX3-AS1 profile in NSCLC tissues and cells was measured by quantitative reverse transcription PCR (qRT-PCR). The RFX3-AS1 overexpression model was constructed. The cell counting kit-8 (CCK-8) experiment and cell colony formation assay were adopted to test cell viability. The cell apoptosis was determined by flow cytometry (FCM). Cell migration and invasion were monitored by the Transwell assay, and Western blot was implemented to verify the protein profiles of signal transducer and activator of transcription 3 (STAT3), E-cadherin, Vimentin and N-cadherin. In vivo, we validated the impact of RFX3-AS1 overexpression on the NSCLC xenograft mouse model. The targeting relationships between RFX3-AS1 and miR-577, miR-577 and STAT3 were confirmed by the dual-luciferase reporter assay. The results manifested that overexpressing RFX3-AS1 markedly facilitated NSCLC cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT), and suppressed cell apoptosis. In contrast, miR-577, which was a downstream target of RFX3-AS1, dramatically impeded the malignant biological behaviors of NSCLC cells. STAT3 was a direct target of miR-577, and it was negatively regulated by the latter. STAT3 activation reversed miR-577-mediated anti-tumor roles. In brief, RFX3-AS1 aggravated NSCLC progression by regulating the miR-577/STAT3 axis.

Methyltransferase 3, N6-adenosine-methyltransferase complex catalytic subunit-induced long intergenic non-protein coding RNA 1833 N6-methyladenosine methylation promotes the non-small cell lung cancer progression via regulating heterogeneous nuclear ribonucleoprotein A2/B1 expression

Long intergenic non-protein coding RNA 1833 (LINC01833) exhibits elevated expression in the non-small cell lung cancer (NSCLC) tissues, while its molecular mechanism in NSCLC progression remains elusive. Herein, the proliferation, migration, invasion as well as apoptosis of NSCLC cells were assessed. The potential N6-methyladenosine (m6A) modification site was predicted by the m6aVar tool. RNA pulldown and m6A-specific immunoprecipitation assays were used to detect the interaction between LINC01833 and methyltransferase 3, N6-adenosine-methyltransferase complex catalytic subunit (METTL3). RNA pull-down together with mass spectrometry were performed to assess the binding relationship between LINC01833 and heterogeneous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1) in NSCLC. Tumor xenograft mice model was established, and the tumor size and weight were measured. The results demonstrated that LINC01833 expression was elevated in NSCLC samples. Overexpression of LINC01833 promoted proliferative, migratory, and invasive abilities and inhibited HCC827 cell apoptosis. LINC01833 knockdown inhibited tumor growth in mice. LINC01833 is further demonstrated to be modulated by METTL3, which is highly expressed in NSCLC samples. In addition, RNA pulldown and m6A-specific immunoprecipitation assays indicated that LINC01833 might form a complex with HNRNPA2B1. In conclusion, m6A transferase METTL3-induced LINC01833 m6A methylation promotes NSCLC progression through modulating HNRNPA2B1 expression. Our findings indicated that LINC01833 might be a therapeutic target for NSCLC.

Long non-coding RNA LINRIS is upregulated in non-small cell lung cancer and its silencing inhibits cell proliferation by suppressing microRNA-10a maturation

Long noncoding RNA LINRIS (LINC00920) is known to participate in colorectal cancer. This study aimed to explore the role of LINRIS in non-small cell lung cancer (NSCLC). NSCLC and adjacent non-tumor tissues were collected from 62 NSCLC patients. LINRIS expression was detected using real-time quantitative PCR (RT-qPCRs). The 62 NSCLC patients were monitored every month for 5 years to evaluate the role of LINRIS in predicting the prognosis of NSCLC. The effects of LINRIS silencing on microRNA-10a (miR-10a) precursor and mature miR-10a levels were assessed by RT-qPCR. Cell proliferation was measured using Cell Counting Kit-8 (CCK-8) assays. LINRIS expression was upregulated in NSCLC tissues. High LINRIS levels predicted poor survival of NSCLC patients. LINRIS were positively correlated with mature (miR-10a) levels but not miR-10a precursor. In NSCLC cells, LINRIS silencing showed no role in miR-10a precursor accumulation but downregulated mature miR10a level. Moreover, LINRIS silencing inhibited cell proliferation, while miR-10a overexpression increased cell proliferation and inhibited the role of LINRIS silencing. Overall, LINRIS silencing may inhibit NSCLC cell proliferation by suppressing miR-10a maturation.

Abbreviations: Non-small cell lung cancer (NSCLC); Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR); LncRNA long intergenic noncoding RNA for IGF2BP2 stability (LINRIS).

Clinicopathological implications of lncRNAs, immunotherapy and DNA methylation in lung squamous cell carcinoma: a narrative review

Objective

To explore the clinicopathological impact of lncRNAs, immunotherapy, and DNA methylation in lung squamous cell carcinoma (LUSC), emphasizing their exact roles in carcinogenesis and modes of action.

Background

LUSC is the second most prevalent form, accounting for around 30% of non-small cell lung cancer (NSCLC). To date, molecular-targeted treatments have significantly improved overall survival in lung adenocarcinoma patients but have had little effect on LUSC therapy. As a result, there is an urgent need to discover new treatments for LUSC that are based on existing genomic methods.

Methods

In this review, we summarized and analyzed recent research on the biological activities and processes of lncRNA, immunotherapy, and DNA methylation in the formation of LUSC. The relevant studies were retrieved using a thorough search of Pubmed, Web of Science, Science Direct, Google Scholar, and the university's online library, among other sources.

Conclusions

LncRNAs are the primary components of the mammalian transcriptome and are emerging as master regulators of a number of cellular processes, including the cell cycle, differentiation, apoptosis, and growth, and are implicated in the pathogenesis of a variety of cancers, including LUSC. Understanding their role in LUSC in detail may help develop innovative treatment methods and tactics for LUSC. Meanwhile, immunotherapy has transformed the LUSC treatment and is now considered the new standard of care. To get a better knowledge of LUSC biology, it is critical to develop superior modeling systems. Preclinical models, particularly those that resemble human illness by preserving the tumor immune environment, are essential for studying cancer progression and evaluating novel treatment targets. DNA methylation, similarly, is a component of epigenetic alterations that regulate cellular function and contribute to cancer development. By methylating the promoter regions of tumor suppressor genes, abnormal DNA methylation silences their expression. DNA methylation indicators are critical in the early detection of lung cancer, predicting therapy efficacy, and tracking treatment resistance. As such, this review seeks to explore the clinicopathological impact of lncRNAs, immunotherapy, and DNA methylation in LUSC, emphasizing their exact roles in carcinogenesis and modes of action.

Long non‑coding RNA LINC01748 exerts carcinogenic effects in non‑small cell lung cancer cell lines by regulating the microRNA‑520a‑5p/HMGA1 axis

The important functions of long non‑coding RNAs in the malignancy of non‑small cell lung cancer (NSCLC) has been increasingly highlighted. However, whether LINC01748 functions in a crucial regulatory role still requires further research. The aim of the present study was to investigate the biological roles of LINC01748 in NSCLC. Furthermore, different experiments were utilized to investigate the mechanism of action of LINC01748 in 2 NSCLC cell lines. Reverse transcription‑quantitative PCR was used to measure mRNA expression levels. Cell Counting Kit‑8 assay, flow cytometry analysis and Transwell and Matrigel assays were also used to analyze, cell viability, apoptosis, and migration and invasion, respectively. A tumor xenograft model was used for in vivo experiments. RNA immunoprecipitation experiments, luciferase reporter assays and rescue experiments were used to investigate the mechanisms involved. Data from The Cancer Genome Atlas dataset and patients recruited into the present study showed that LINC01748 was overexpressed in NSCLC. Patients with high LINC01748 mRNA expression level had shorter overall survival rate compared with that in patients with low LINC01748 mRNA expression level. Then, knockdown of LINC01748 mRNA expression level reduced cell proliferation, migration and invasion, but increased cell apoptosis in vitro. Knockdown of LINC01748 also reduced tumor growth in vivo. Mechanistically, LINC01748 could act as a competing endogenous (ce)RNA to sponge microRNA(miR)‑520a‑5p, to increase the expression level of the target gene, high mobility group AT‑hook 1 (HMGA1) in the NSCLC cell lines. Furthermore, rescue experiments illustrated that the functions exerted by LINC01748 knockdown were negated by miR‑520a‑5p inhibition or HMGA1 overexpression. In summary, LINC01748 acted as a ceRNA by sponging miR‑520a‑5p, leading to HMGA1 overexpression, thus increasing the aggressiveness of the NSCLC cells. Accordingly, targeting the LINC01748/miR‑520a‑5p/HMGA1 pathway may benefit NSCLC therapy.

JMJD2C-mediated long non-coding RNA MALAT1/microRNA-503-5p/SEPT2 axis worsens non-small cell lung cancer

Jumonji domain containing protein 2C (JMJD2C) could epigenetically regulate cancer cells. We specifically explored the downstream mechanism of JMJD2C in non-small cell lung cancer (NSCLC) from the long non-coding RNA metastasis associated with lung adenocarcinoma transcript 1/microRNA-503-5p/septin 2 (MALAT1/miR-503-5p/SEPT2) axis. NSCLC clinical tissues were utilized to assess JMJD2C, MALAT1, miR-503-5p and SEPT2 levels. NSCLC cell lines (A549 and H1299) were applied for loss-of-function and gain-of-function tests to identify the functional roles of JMJD2C, MALAT1, miR-503-5p, and SEPT2. The interactions among JMJD2C, MALAT1, miR-503-5p, and SEPT2 were assessed. Augmented JMJD2C, MALAT1, and SEPT2 and reduced miR-503-5p levels were found in NSCLC. Depleting JMJD2C or MALAT1, or restoring miR-503-5p exerted anti-tumor effects on NSCLC cells in vitro and in vivo. JMJD2C is bound to the promoter of MALAT1. MALAT1 bound to miR-503-5p and miR-503-5p targeted SEPT2. Knocking down MALAT1 or SEPT2, or elevating miR-503-5p mitigated the pro-tumor effects of upregulated JMJD2C on NSCLC. It is evident that the JMJD2C-mediated MALAT1/miR-503-5p/SEPT2 axis takes part in the process of NSCLC and even worsens NSCLC.

LncRNA SOCS2-AS1 promotes the progression of glioma via regulating ITGB1 expression

BACKGROUND

Accumulating evidence has underscored the important role of long non-coding RNAs (lncRNAs) in the development and progression of glioma. However, the role of lncRNA SOCS2-AS1 in glioma is largely unknown.

METHODS

lncRNA SOCS2-AS1 silencing was achieved by specific siRNAs. Proliferation of glioma cell line after lncRNA SOCS2-AS1 silencing was examined by MTT assay, Transwell assay was used to confirm changes of invasion and migration of glioma cells, and study the molecular mechanism of lncRNA SOCS2-AS1 by RT-qPCR and bioinformatics analysis.

RESULTS

We identified that lncRNA SOCS2-AS1 was significantly upregulated in glioma, and its overexpression was closely related with malignant clinical features and poor prognosis. To explore the cellular function of SOCS2-AS1, we performed loss-of function assays in two glioma cells. We demonstrated that SOCS2-AS1 knockdown repressed glioma cell proliferation, migration and invasion. Mechanistically, SOCS2-AS1 expression was positively correlated with the expression levels of core factors ITGB1 of ECM-receptor interaction signaling pathway in glioma. Moreover, SOCS2-AS1 knockdown suppressed ITGB1 expression in glioma cells. Finally, rescue assays were carried out to determine that ITGB1 involved in SOCS2-AS1-mediated glioma cell proliferation, migration and invasion.

CONCLUSION

Our findings provided the first evidence suggested that SOCS2-AS1 promoted the progression of glioma via upregulating ITGB1 expression.

lncRNA TPT1‑AS1 knockdown inhibits liver cancer cell proliferation, migration and invasion

Long non-coding RNA (lncRNA) tumor protein translationally controlled 1 antisense RNA 1 (TPT1-AS1) serves as an oncogene in several tumors, including ovarian and cervical cancer. However, the functional role of TPT1-AS1 in liver cancer (LC) is not completely understood. The present study aimed to explore the role of TPT1-AS1 in LC. In this study, the reverse transcription-quantitative PCR results demonstrated that TPT1-AS1 expression was significantly upregulated in LC tissues and cell lines compared with adjacent paracancerous tissues and THLE-3 cells, respectively. Elevated TPT1-AS1 expression was significantly associated with TNM stage lymph node metastasis and poor prognosis in patients with LC, as determined via χ² and Kaplan-Meier survival analyses. By constructing TPT1-AS1 knockdown LC cell lines (HepG2 and SNU-182), loss-of-function experiments, including Cell Counting Kit-8, colony formation, flow cytometry, wound healing and Transwell assays, were performed to explore the function role of TPT1-AS1 in LC in vitro. The results demonstrated that TPT1-AS1 knockdown inhibited LC cell proliferation, G₁/S transition, migration and invasion compared with the small interfering RNA (si)-negative control (NC) group. Mechanistically, TPT1-AS1 knockdown markedly decreased CDK4, N-cadherin and Vimentin expression levels, but notably increased p21 and E-cadherin expression levels compared with the si-NC group. Therefore, the results of the present study suggested that TPT1-AS1 might serve as a promising therapeutic target for LC treatment.

Long noncoding RNA LINC01703 exacerbates the malignant properties of non-small-cell lung cancer by upregulating MACC1 in a microRNA-605-3p-mediated manner

Long intergenic nonprotein coding RNA 1703 (LINC01703) has diagnostic significancein lung adenocarcinoma. However, its specific roles in non-small-cell lung cancer(NSCLC) and downstream mechanisms have not been investigated. In the current study,we characterized the role of LINC01703 in NSCLC malignancy and elucidated itsdetailed mechanism of action. LINC01703 expression was measured by qRT-PCR. Theregulatory effects of LINC01703 on the malignancy of NSCLC cells were assessed bymultiple functional experiments. The targeted interaction was confirmed by RNAimmunoprecipitation and luciferase reporter assays. Herein, overexpression ofLINC01703 in NSCLC was indicated in the TCGA database and further proven in ourcohort. Functional studies revealed that knocking down LINC01703 repressed cellproliferation, colony formation, migration and invasion in vitro, which wasaccompanied by the induction of apoptosis. The tumor growth of LINC01703-silencedcells was also inhibited in vivo. Mechanistic analyses revealed that LINC01703functioned as a competing endogenous RNA for microRNA-605-3p (miR-605-3p) inNSCLC cells, which thereby upregulated the miR-605-3p target metastasis associatedwith colon cancer 1 (MACC1). Rescue experiments highlighted that the regulatoryactions of LINC01703 ablation on NSCLC cells were abolished in response to miR-605-3p downregulation or MACC1 overexpression. In conclusion, LINC01703enhanced the aggressiveness of NSCLC cells by altering miR-605-3p/MACC1. Ourwork suggests the therapeutic potential of LINC01703/miR-605-3p/MACC1 in NSCLC.

Long non-coding RNA DLX6-AS1 knockdown suppresses the tumorigenesis and progression of non-small cell lung cancer through microRNA-16-5p/BMI1 axis

BACKGROUND

Non-small cell lung cancer (NSCLC) is a huge threat to sufferers' life and overall health. Long non-coding RNA (lncRNA) distal-less homeobox 6 antisense RNA 1 (DLX6-AS1) has been revealed to function as a carcinogenesis factor in some cancers. This research aimed to scrutinize the role and mechanism underlying DLX6-AS1 in NSCLC tumorigenesis and progression.

METHODS

The levels of DLX6-AS1, microRNA-16-5p (miR-16-5p), and BMI1 mRNA were estimated via reverse transcription-quantitative PCR (RT-qPCR) assay. The protein levels were disclosed by western blot assay. Cell proliferative potential was estimated by colony formation and Cell Counting Kit-8 (CCK-8) assays. Cell migration was estimated by Transwell and wound healing assay. A Transwell assay was executed to estimate cell invasion. The relationships of DLX6-AS1, miR-16-5p, and BMI1 were forecasted by bioinformatics analysis, and confirmed by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. A xenograft mice model was employed to to inspect the function of DLX6-AS1 knockdown on NSCLC tumorigenesis in vivo.

RESULTS

DLX6-AS1 was overexpressed in NSCLC tissues and cells, and was inextricably linked with the poor prognosis of NSCLC patients. Depletion of DLX6-AS1 oppressed cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT) but promoted apoptosis in NSCLC. MiR-16-5p is a target of DLX6-AS1 and directly targets BMI1. Moreover, the anti-tumor impacts of miR-16-5p were overturned by overexpression of DLX6-AS1 or BMI1 in NSCLC cells. Additionally, DLX6-AS1 silencing inhibited tumor growth of NSCLC in vivo.

CONCLUSIONS

In conclusion, lncRNA DLX6-AS1 downregulation suppressed the tumorigenesis and progression of NSCLC via miR-16-5p/BMI1 axis in vitro and in vivo, elucidating the vital roles and downstream targets of DLX6-AS1 in NSCLC.

Predictions of the dysregulated competing endogenous RNA signature involved in the progression of human lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer worldwide. Until now, the molecular mechanisms underlying LUAD progression have not been fully explained. This study aimed to construct a competing endogenous RNA (ceRNA) network to predict the progression in LUAD.

METHODS

Differentially expressed lncRNAs (DELs), miRNAs (DEMs), and mRNAs (DEGs) were identified from The Cancer Genome Atlas (TCGA) database with a |log2FC|> 1.0 and a false discovery rate (FDR) < 0.05. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein-protein interaction (PPI) network, and survival analyses were performed to analyse these DEGs involved in the ceRNA network. Subsequently, the drug-gene interaction database (DGIdb) was utilized to select candidate LUAD drugs interacting with significant DEGs. Then, lasso-penalized Cox regression and multivariate Cox regression models were used to construct the risk score system. Finally, based on the correlations between DELs and DEGs involved in the risk score system, the final ceRNA network was identified. Meanwhile, the GEPIA2 database and immunohistochemical (IHC) results were utilized to validate the expression levels of selected DEGs.

RESULTS

A total of 340 DELs, 29 DEMs, and 218 DEGs were selected to construct the initial ceRNA network. Functional enrichment analyses indicated that 218 DEGs were associated with the KEGG pathway terms "microRNAs in cancer", "pathways in cancer", "cell cycle", "HTLV-1 infection", and the "PI3K-Akt signalling pathway". K-M survival analysis of all differentially expressed genes involved in the ceRNA network identified 24 DELs, 4 DEMs, and 29 DEGs, all of which were significantly correlated with LUAD progression (P< 0.05). Furthermore, 15 LUAD drugs interacting with 29 significant DEGs were selected. After lasso-penalized Cox regression and multivariate Cox regression modelling, PRKCE, DLC1, LATS2, and DPY19L1 were incorporated into the risk score system, and the results suggested that LUAD patients who had the high-risk score always suffered from a poorer overall survival. Additionally, the correlation coefficients between these 4 DEGs and their corresponding DELs involved in the ceRNA network suggested that there were 2 significant DEL-DEG pairs, NAV2-AS2 - PRKCE (r= 0.430, P< 0.001) and NAV2-AS2 - LATS2 (r= 0.338, P< 0.001). And NAV2-AS2 - mir-31 - PRKCE and NAV2-SA2 - mir-31 - LATS2 were finally identified as ceRNA network involved in the progression of LUAD.

CONCLUSIONS

The lncRNA-miRNA-mRNA ceRNA network plays an essential role in predicting the progression of LUAD. These results may improve our understanding and provide novel mechanistic insights to explore prognosis and therapeutic drugs for LUAD patients.

Long noncoding RNA MGC27382 inhibits proliferation and metastasis of non-small cell lung cancer cells via down-regulating AKT/GSK3β pathway

PURPOSE

Persistent abnormal proliferation and long distant metastasis of tumors contribute to high mortality rate in non-small cell lung cancer (NSCLC) patients. Strategies that prevent NSCLC proliferation and/or metastasis have been studied but still need to be further explored. Numerous studies have proved the diversity functions of long noncoding RNAs (lncRNAs) exerted in cancer, including NSCLC. In this study, we aim to identify and investigate the role of novel lncRNAs in NSCLC progression.

METHODS

RNA sequence data were retrieved from the Cancer Genome Atlas (TCGA), differentially expressed lncRNAs (DElncRNAs) were screened out based on the R language, then real-time PCR experiment was introduced to detect the DElncRNA expression levels. A series of experiments including MTT, cell cycle, transwell, and wound healing assays were employed to explore the effect of DElncRNA MGC27382 on cell proliferation and invasion ability.

RESULTS

We detected that DElncRNA MGC27382 is down-regulated in NSCLC tissues and cells. Overexpression of MGC27382 prevented NSCLC cell proliferation via down-regulating cyclin D1 and cyclin E. Moreover, wound healing and transwell assays indicated that the ability of cell invasion and migration could be impaired when cells were treated with MGC27382 overexpression. Further studies demonstrated that MGC27382-mediated inhibition on NSCLC progression can be impaired by LY294002, which is a frequently used inhibitor of AKT/GSK3β pathway.

CONCLUSION

MGC27382 is down-regulated in NSCLC. It exerts an inhibitory role in NSCLC development through suppressing the AKT/GSK3β pathway. Our results indicate that the lncRNA MGC27382 might be a tumor-suppressor gene in NSCLC. Overexpression of MGC27382 is thought to be a potential strategy for overcoming NSCLC progression.

Long non-coding RNA SLC25A25-AS1 exhibits oncogenic roles in non-small cell lung cancer by regulating the microRNA-195-5p/ITGA2 axis

Long non-coding RNA SLC25A25 antisense RNA 1 (SLC25A25-AS1) exerts antitumour activity in colorectal cancer. The present study investigated whether SLC25A25-AS1 is implicated in the aggressiveness of non-small cell lung cancer (NSCLC) and the possible underlying mechanism. SLC25A25-AS1 expression in NSCLC was determined by reverse transcription-quantitative PCR. The proliferation, apoptosis, migration and invasion of NSCLC cells were tested in vitro through cell counting kit-8 assay, flow cytometry analysis, Transwell migration and invasion assays, followed by in vivo validation using animal experiments. Additionally, the competitive endogenous RNA theory for SLC25A25-AS1, microRNA-195-5p (miR-195-5p) and integrin α2 (ITGA2) was identified using subcellular fractionation, bioinformatics analysis, reverse transcription-quantitative PCR, western blotting, a luciferase assay and RNA immunoprecipitation. As compared with normal lung tissues, increased expression of SLC25A25-AS1 was demonstrated in NSCLC tissues using The Cancer Genome Atlas database.. In addition, SLC25A25-AS1 was overexpressed in both NSCLC tissues and cell lines. High SLC25A25-AS1 expression was markedly associated with shorter overall survival time of patients with NSCLC. SLC25A25-AS1 silencing impeded NSCLC cell proliferation and triggered apoptosis, while restricting cell migration and invasion. Tumour growth in vivo was also impaired by SLC25A25-AS1 silencing. Mechanistically, SLC25A25-AS1 was demonstrated to be an miR-195-5p sponge in NSCLC cells. miR-195-5p mimics decreased ITGA2 expression in NSCLC cells by directly targeting ITGA2, and SLC25A25-AS1 interference decreased ITGA2 expression by sequestering miR-195-5p. Furthermore, the antitumour effects of SLC25A25-AS1 silencing on malignant behaviours were counteracted when ITGA2 was restored or when miR-195-5p was silenced. In summary, by controlling the miR-195-5p/ITGA2 axis, SLC25A25-AS1 served tumour-promoting roles in NSCLC cells. Therefore, the SLC25A25-AS1/miR-195-5p/ITGA2 signalling pathway might be an attractive target for future therapeutic options in NSCLC.

Atezolizumab and blockade of LncRNA PVT1 attenuate cisplatin resistant ovarian cancer cells progression synergistically via JAK2/STAT3/PD-L1 pathway

OBJECTIVE

To investigate the relationship between lncRNA PVT1(PVT1) level and PD-L1 expression and their functions in cisplatin resistant epithelial ovarian cancer (CREOC).

METHODS

PVT1 and PD-L1 in ovarian cancer tissues were detected and analyzed. The cells proliferation, apoptosis, invasion abilities and potential mechanism were detected by cell functional experiments and western-blot assay, respectively.

RESULTS

The average expressions of PVT1 and PD-L1 in CREOC tissues were significantly higher. The expression of PVT1 is positively associated with PD-L1 in CREOC. Higher expressions of PVT1 and PD-L1 indicated more malignant clinical behavior and shorter PFS and OS. Knockdown of PVT1 inhibited the proliferation and invasion and promote apoptosis for A2780cis cells, which may be related to decrease the expression of PD-L1 via repressing JAK2/STAT3 pathway.

CONCLUSIONS

The synergistic therapeutic strategy using LncRNA PVT1-targeted therapy and immune checkpoint blockade of PD-L1 warrant study further for ovarian cancer patients with cisplatin resistant recurrence.

Long Non-Coding RNA CRNDE Is Involved in Resistance to EGFR Tyrosine Kinase Inhibitor in EGFR-Mutant Lung Cancer via eIF4A3/MUC1/EGFR Signaling

(1) Background: Acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is an intractable problem for many clinical oncologists. The mechanisms of resistance to EGFR-TKIs are complex. Long non-coding RNAs (lncRNAs) may play an important role in cancer development and metastasis. However, the biological process between lncRNAs and drug resistance to EGFR-mutated lung cancer remains largely unknown. (2) Methods: Osimertinib- and afatinib-resistant EGFR-mutated lung cancer cells were established using a stepwise method. A microarray analysis of non-coding and coding RNAs was performed using parental and resistant EGFR-mutant non-small cell lung cancer (NSCLC) cells and evaluated by bioinformatics analysis through medical-industrial collaboration. (3) Results: Colorectal neoplasia differentially expressed (CRNDE) and DiGeorge syndrome critical region gene 5 (DGCR5) lncRNAs were highly expressed in EGFR-TKI-resistant cells by microarray analysis. RNA-protein binding analysis revealed eukaryotic translation initiation factor 4A3 (eIF4A3) bound in an overlapping manner to CRNDE and DGCR5. The CRNDE downregulates the expression of eIF4A3, mucin 1 (MUC1), and phospho-EGFR. Inhibition of CRNDE activated the eIF4A3/MUC1/EGFR signaling pathway and apoptotic activity, and restored sensitivity to EGFR-TKIs. (4) Conclusions: The results showed that CRNDE is associated with the development of resistance to EGFR-TKIs. CRNDE may be a novel therapeutic target to conquer EGFR-mutant NSCLC.

Landscape of epigenetically regulated lncRNAs and DNA methylation in smokers with lung adenocarcinoma

In this study, we identified long non-coding RNAs (lncRNAs) associated with DNA methylation in lung adenocarcinoma (LUAD) using clinical and methylation/expression data from 184 qualified LUAD tissue samples and 21 normal lung-tissue samples from The Cancer Genome Atlas (TCGA). We identified 1865 differentially expressed genes that correlated negatively with the methylation profiles of normal lung tissues, never-smoker LUAD tissues and smoker LUAD tissues, while 1079 differentially expressed lncRNAs were identified using the same criteria. These transcripts were integrated using ingenuity pathway analysis to determine significant pathways directly related to cancer, suggesting that lncRNAs play a crucial role in carcinogenesis. When comparing normal lung tissues and smoker LUAD tissues, 86 candidate genes were identified, including six lncRNAs. Of the 43 candidate genes revealed by comparing never-smoker LUAD tissues and smoker LUAD tissues, 13 were also different when compared to normal lung tissues. We then investigated the expression of these genes using the Gene Expression of Normal and Tumor Tissues (GENT) and Methylation and Expression Database of Normal and Tumor Tissues (MENT) databases. We observed an inverse correlation between the expression of 13 genes in normal lung tissues and smoker LUAD tissues, and the expression of five genes between the never-smoker and smoker LUAD tissues. These findings were further validated in clinical specimens using bisulfite sequencing, revealing that AGR2, AURKB, FOXP3, and HMGA1 displayed borderline differences in methylation. Finally, we explored the functional connections between DNA methylation, lncRNAs, and gene expression to identify possible targets that may contribute toward the pathogenesis of cigarette smoking-associated LUAD. Together, our findings suggested that differentially expressed lncRNAs and their target transcripts could serve as potential biomarkers for LUAD.

LINC00665 functions as a competitive endogenous RNA to regulate AGTR1 expression by sponging miR‑34a‑5p in glioma

Glioma is the most aggressive tumor of the central nervous system. Long non-coding RNAs (lncRNAs) may be involved in modulating tumor generation. The present study analyzed an lncRNA microarray of glioma and selected long intergenic non-protein coding RNA 665 (LINC00665) as the research object. The mode of expression and biological function of LINC00665 in glioma were assessed using lncRNA microarray and RT-qPCR analyses. Gain-of-function assays and/or loss-of-function assays were implemented to explore the role of LINC00665 in the progression of glioma. Dual-luciferase reporter and RNA immunoprecipitation assays explored the downstream molecular mechanism of LINC00665. The function of the molecular pathway in progression of glioma was analyzed using rescue assays. High expression of LINC00665 was marked in glioma tissues and cells, which correlated with an unsatisfactory prognosis. Upregulation of LINC00665 significantly promoted the proliferation and invasion of glioma cells. LINC00665 acted as a competing endogenous RNA by sponging miR-34a-5p to upregulate angiotensin II receptor type 1 (AGTR1). LINC00665 promoted the progression of glioma by acting as a competitive endogenous RNA to competitively bind to miR-34a-5p and mediate AGTR1 expression.

Long non-coding RNAs as potential biomarkers in the prognosis and diagnosis of lung cancer: A review and target analysis

Long non-coding RNAs (lncRNA) have been emerged as a novel class of molecular regulators in cancer. They are dysregulated in many types of cancer; however, there is not enough knowledge available on their expression and functional profiles. Lung cancer is the leading cause of the cancer deaths worldwide. Generally, lncRNAs may be associated with lung tumor pathogenesis and they may act as biomarkers for the cancer prognosis and diagnosis. Compared to other invasive prognostic and diagnostic methods, detection of lncRNAs might be a user-friendly and noninvasive method. In this review article, we selected 27 tumor-associated lncRNAs by literature reviewing to further discussing in detail for using as diagnostic and prognostic biomarkers in lung cancer. Also, in an in silico target analysis, the "Experimentally supported functional regulation" approach of the LncTarD web tool was used to identifying the target genes and regulatory mechanisms of the selected lncRNAs. The reports on diagnostic and prognostic potential of all selected lncRNAs were discussed. However, the target genes and regulatory mechanisms of the 22 lncRNAs were identified by in silico analysis and we found the pathways that are controlled by each target group of lncRNAs. They use epigenetic mechanisms, ceRNA mechanisms, protein interaction and sponge mechanism. Also, 10, 23, 5, and 28 target genes for each of these mechanisms were identified, respectively. Finally, each group of target genes controls 50, 12, 7, and 2 molecular pathways, respectively. In conclusion, LncRNAs could be used as biomarkers in lung cancer due to their roles in control of several signaling pathways related to lung tumors. Also, it seems that lncRNAs, which use epigenetic mechanisms for modulating a large number of pathways, could be considered as important subjects for lung cancer-related diagnostic and prognostic biomarkers.

LncRNA MALAT1 accelerates non-small cell lung cancer progression via regulating miR-185-5p/MDM4 axis

Non-small cell lung cancer (NSCLC) is the commonest malignancy with high death rate around the world. LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is greatly overexpressed in multifarious cancers, including NSCLC. However, the precise mechanism of MALAT1 in NSCLC tumorigenesis is blurry. This paper aims to investigate the theory of MALAT1 action in NSCLC progression. The levels of MALAT1, microRNA (miR)-185-5p, and mouse double minute 4 protein (MDM4) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Cell proliferation and apoptosis were, respectively, determined by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay, and flow cytometry. Cell migratory and invasive abilities were inspected by transwell assay. The binding relationship between miR-185-5p and MALAT1 or MDM4 was confirmed by dual-luciferase reporter assay. The impacts of MALAT1 on tumor growth in vivo were measured by a xenograft experiment. We found MALAT1 and MDM4 were upregulated and MALAT1 positively regulated the MDM4 expression. MALAT1 and MDM4 deletion significantly hindered the proliferation, metastasis, and expedited the apoptosis of NSCLC cells. MDM4 overexpression partly overturned the influence of MALAT1 downregulation on cell development. Moreover, miR-185-5p, as a target of MALAT1, could directly target MDM4, and miR-185-5p upregulation exerted inhibitory effects on NSCLC cells. Besides, knockdown of MALAT1 inhibited tumor growth in vivo through miR-185-5p/MDM4 axis in NSCLC. Collectively, MALAT1 contributed to proliferation, migration, invasion, and impeded apoptosis by regulating the MDM4 expression mediated by miR-185-5p in NSCLC cells.

The noncoding RNA BC200 associates with polysomes to positively regulate mRNA translation in tumor cells

BC200 is a noncoding RNA elevated in a broad spectrum of tumor cells that is critical for cell viability, invasion, and migration. Overexpression studies have implicated BC200 and the rodent analog BC1 as negative regulators of translation in both cell-based and in vitro translation assays. Although these studies are consistent, they have not been confirmed in knockdown studies and direct evidence for this function is lacking. Herein, we have demonstrated that BC200 knockdown is correlated with a decrease in global translation rates. As this conflicts with the hypothesis that BC200 is a translational suppressor, we overexpressed BC200 by transfection of in vitro transcribed RNA and transient expression from transfected plasmids. In this context BC200 suppressed translation; however, an innate immune response confounded the data. To overcome this, breast cancer cells stably overexpressing BC200 and various control RNAs were developed by selection for genomic incorporation of a plasmid coexpressing BC200 and the neomycin resistance gene. Stable overexpression of BC200 was associated with elevated translation levels in pooled stable cell lines and isolated single-cell clones. Cross-linking sucrose density gradient centrifugation demonstrated an association of BC200 and its reported binding partners SRP9/14, CSDE1, DHX36, and PABPC1 with both ribosomal subunits and polysomal RNA, an association not previously observed owing to the labile nature of the interactions. In summary, these data present a novel understanding of BC200 function as well as optimized methodology that has far reaching implications in the study of noncoding RNAs, particularly within the context of translational regulatory mechanisms.

SNHG3 Knockdown Suppresses Proliferation, Migration and Invasion, and Promotes Apoptosis in Non-Small Cell Lung Cancer Through Regulating miR-216a/ZEB1 Axis

Background

Tumour growth and development are dependent on many factors including long noncoding RNAs (lncRNAs). However, limited information is available on the involvement of lncRNAs in non-small cell lung cancer (NSCLC) and the molecular mechanisms have not been defined. Here, we examined the expression of small nucleolar RNA host gene 3 (SNHG3) and its contribution to the development of NSCLC.

Methods

We detected SNHG3, miR-216a, and ZEB1 expression in tissues from NSCLC patients and lung adenocarcinoma cell lines using quantitative real-time polymerase chain reaction. Proliferation, migrations, invasion, and apoptosis of tumour cells were assessed using cell counting kit-8, transwell experiments, and flow cytometry after SNHG3 knockdown by small interfering RNAs. Bioinformatics and luciferase reporter assays were employed for analysing the interactions between SNHG3, miR-216a, and ZEB1.

Results

We found highly upregulated SNHG3 in tissues and cells from NSCLC patients, which was linked to poor prognosis. SNHG3 silencing diminished the ability of NSCLC cells to proliferate, migrate, and invade and promoted apoptosis. Furthermore, SNHG3 competed with endogenous RNA and enhanced the expression of ZEB1 by interfering with miR-216a. ZEB1 overexpression or miR-216a blockade reversed SNHG3-induced tumour inhibition. Similar effects were observed in vivo where SNHG3 knockdown inhibited NSCLC tumour growth by reducing expression of miR-216a while increasing that of ZEB1.

Conclusion

Knockdown of SNHG3 inhibits NSCLC tumour development and progression by upregulation of ZEB1 and interference with miR-216a, revealing an attractive alternative target for patients with NSCLC.

Expression of long noncoding RNA NBAT1 is associated with the outcome of patients with non-small cell lung cancer

OBJECTIVE Long noncoding RNA neuroblastoma-associated transcript 1 (NBAT1) has been reported to be involved in cancer progression. However, the clinical significance of NBAT1 in non-small cell lung cancer (NSCLC) is still unclear. Our present research aimed to explore whether NBAT1 serves as a biomarker for NSCLC prognosis. METHODS The expression of NBAT1 was examined by RT-PCR in tissue samples of 162 NSCLC patients and was compared with the adjacent non-tumor lung specimens. Then the association between NBAT1 expression and clinical-pathological parameters was further evaluated. Survival analysis was performed using the Kaplan-Meier method. The prognostic significance of NBAT1 expression in NSCLC patients was explored by the use of univariate and multivariate analyses. RESULTS NBAT1 expression was prominently decreased in NSCLC tissues compared with matched normal lung specimens (p < 0.01). Moreover, survival analyses indicated that patients with low expression displayed dramatically decreased 5-year overall survival (p = 0.008). CONCLUSIONS NBAT1 expression might contribute to tumor progression and poor prognosis of NSCLC and might be a new therapeutic target in NSCLC.

Long noncoding RNA CBR3 antisense RNA 1 promotes the aggressive phenotypes of non‑small‑cell lung cancer by sponging microRNA‑509‑3p and competitively upregulating HDAC9 expression

Long noncoding RNA CBR3 antisense RNA 1 (CBR3‑AS1) plays significant roles in the initiation and progression of osteosarcoma. The aim of the present study was to investigate the involvement of CBR3‑AS1 in the development of non‑small cell lung cancer (NSCLC). Reverse transcription‑quantitative PCR was performed to detect CBR3‑AS1 expression in NSCLC tissues and cell lines. The impacts of CBR3‑AS1 on cellular proliferation, apoptosis, migration and invasiveness in vitro, and tumor growth in vivo, were investigated using the Cell Counting Kit‑8 assay, flow cytometry, Transwell migration and invasion assays, and tumor xenograft model‑based analysis, respectively. The results indicated that CBR3‑AS1 was markedly upregulated in NSCLC tissues and cell lines. High CBR3‑AS1 expression was correlated with larger tumor size, advanced TNM stage, increased incidence of lymph node metastasis and shorter overall survival times in patients with NSCLC. Furthermore, CBR3‑AS1‑knockdown notably suppressed cellular proliferation, migration and invasiveness in vitro, and also promoted apoptosis and suppressed tumorigenicity in vivo. Mechanistic investigation demonstrated that CBR3‑AS1 functions as a competing endogenous RNA for microRNA‑509‑3p (miR‑509‑3p) in NSCLC cells. Furthermore, miR‑509‑3p exerted tumor‑suppressive effects in NSCLC, and histone deacetylase 9 (HDAC9) was identified as a direct target of miR‑509‑3p. HDAC9 expression was suppressed by CBR3‑AS1 depletion, which was abolished by miR‑509‑3p inhibition. Further rescue experiments revealed that increasing the output of the miR‑509‑3p/HDAC9 axis counteracted the CBR3‑AS1 depletion‑induced inhibitory effects on NSCLC cells. Collectively, the results of the present study indicate that the CBR3‑AS1/miR‑509‑3p/HDAC9 pathway exerts tumor‑promoting actions in NSCLC oncogenesis and progression, suggesting that this pathway is an effective target for the management of NSCLC.

Immune-related long non-coding RNA signature identified prognosis and immunotherapeutic efficiency in bladder cancer (BLCA)

Background

As bladder cancer was recognized to be immunogenic, dozens of studies have focused on immune biology of BLCA, but little is known about its relationship with the long non-coding RNAs (lncRNAs).

Methods

LASSO Cox regression model was used to establish immune-related lncRNAs signature (IRLS) in BLCA. The immune infiltration landscape of BLCA was conducted via ssGSEA and immunotherapy response was calculated through TIDE algorithm.

Results

A total of 82 immune-related lncRNAs were screened out according to spearman correlation analysis with the immune score (|R| > 0.4, p < 0.05). We selected 5 prognostic lncRNAs to construct immune-related lncRNAs signature (IRLS) through LASSO Cox regression analysis. Then we validated that 5 enrolled lncRNAs was downregulated in BLCA tissues and cells when compared with paracancerous tissues and normal bladder epithelium cell. The univariate and multivariate Cox regression analysis both demonstrated the IRLS was a robust independent prognostic factor in overall survival prediction with high accuracy. The GSVA and GSEA also suggested that the IRLS are involved in the immune-related biological processes and pathways which are very well known in the context of BLCA tumorigenesis. In addition, we found that IRLS is strikingly positive correlated with tumour microenvironment (TME) immune cells infiltration and expression of critical immune checkpoints, indicating that the poor prognosis might be caused partly by immunosuppressive TME. Finally, the results from the TIDE analysis revealed that IRLS could efficiently predict the clinical response of immunotherapy in BLCA.

Conclusion

We have developed a novel IRLS, which have a latent prognostic value for BLCA patients and might facilitate personalized counselling for immunotherapy.

Long Non-coding RNA MRUL Contributes to Osteosarcoma Progression Through the miR-125a-5p/FUT4 Axis

Osteosarcoma (OS) originates in the skeletal system and has a rising global incidence. Long Non-coding RNAs (lncRNAs) are key regulators of human cancers development and progression. However, their roles in the development of OS are not well understood. This research aimed to investigate the effect of a long non-coding RNA (lncRNA), MRUL, on OS and revealed its potential molecular mechanisms. The bioinformatics analysis demonstrated that lncRNA MRUL was involved in regulating nucleic acid-templated transcription, cellular macromolecule biosynthetic process, immune response, and inflammatory response. In this work, the expression of lncRNA MRUL was detected by quantitative real-time polymerase chain reaction (qRT-RCR) in both cancer tissues and cell lines. We found that lncRNA MRUL was up-regulated in cancer tissues and cell lines. Functional experiments showed that knockdown of lncRNA MRUL inhibited OS cell proliferation, and metastasis. At the same time, we found that lncRNA MRUL interacted with miR-125a-5p to suppress FUT4 expression. Moreover, inhibition of miR-125a-5p abrogated the biological roles of lncRNA MRUL knockdown on OS cell proliferation, migration, and invasion. In conclusion, these results demonstrated that OS-upregulated lncRNA MRUL promoted cell proliferation, and metastasis via negatively regulating miR-125a-5p, and imply that lncRNA MRUL may be a potential biomarker for OS.

Sputum long non-coding RNA biomarkers for diagnosis of lung cancer

BACKGROUND

Analysis of molecular changes in sputum may help diagnose lung cancer. Long non-coding RNAs (lncRNAs) play vital roles in various biological processes, and their dysregulations contribute to the development and progression of lung tumorigenesis. Herein, we determine whether aberrant lncRNAs could be used as potential sputum biomarkers for lung cancer.

METHODS

Using reverse transcription PCR, we measure expressions of lung cancer-associated lncRNAs in sputum of a discovery cohort of 67 lung cancer patients and 65 cancer-free smokers with benign diseases and a validation cohort of 59 lung cancer patients and 60 cancer-free smokers with benign diseases.

RESULTS

In the discovery cohort, four of the lncRNAs displayed a significantly different level in sputum of lung cancer patients vs.cancer-free smokers with benign diseases (all P< 0.001). From the four lncRNAs, three lncRNAs (SNHG1, H19, and HOTAIR) are identified as a biomarker panel, producing 82.09% sensitivity and 89.23% specificity for diagnosis of lung cancer. Furthermore, the biomarker panel has a higher sensitivity (82.09% vs. 52.24%, P= 0.02) and a similar specificity compared with sputum cytology (89.23% vs. 90.77%, P= 0.45). In addition, the lncRNA biomarker panel had a higher sensitivity (87.50% vs. 70.07%, p= 0.03) for diagnosis of squamous cell carcinoma compared with adenocarcinoma of the lung, while maintaining the same specificity (89.23%). The potential of the sputum lncRNA biomarkers for lung cancer detection is confirmed in the validation cohort.

CONCLUSION

We have for the first time shown that the analysis of lncRNAs in sputum might be a noninvasive approach for diagnosis of lung cancer.

Tumor-derived urinary exosomal long non-coding RNAs as diagnostic biomarkers for bladder cancer

Bladder cancer (BC) is the sixth most common malignancy in men and 17th in women. Exosomal long non-coding RNAs (lncRNAs) have been defined as a novel biomarker for BC. The aim of this study is to evaluate the clinical significance of urine exosomal PVT-1, ANRIL and PCAT-1 as a biomarker in BC patients with tumors classified as T1 or T2. Exosomes were isolated from urine of BC patients and healthy donors, then characterized according to their shape, size, and exosome markers by Electron Microscopy, Dynamic light scattering, and Western blotting. Exosomal lncRNAs extraction was done to determine the expression levels of PVT-1, ANRIL and PCAT-1 by qRT-PCR. ANRIL and PCAT-1 expression was significantly higher in BC patients compared to normal subjects. To evaluate the performance of the identified lncRNAs for BC detection, we performed ROC curves analysis. The diagnostic accuracy of ANRIL and PCAT-1, measured by AUC, was 0.7229 (sensitivity = 46.67 % and specificity = 87.5 %) and 0.7292 (sensitivity = 43.33 % and specificity = 87.5 %). Transcript levels of lncRNAs in urinary exosomes are potential diagnostic biomarkers in bladder cancer.

LINC00028 regulates the development of TGFβ1-treated human tenon capsule fibroblasts by targeting miR-204-5p

Glaucoma is a leading cause of blindness worldwide with complex pathogenesis. The excessive proliferation and fibrosis of human tenon capsule fibroblasts (HTFs) trigger the scar formation after glaucoma filtration surgery. The purpose was to investigate the role of long intergenic non-protein coding RNA 28 (LINC00028) and mechanism in transforming growth factor β1 (TGFβ1)-treated HTFs. The detection of LINC00028 and miR-204-5p expression was conducted using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was assessed by cell counting kit-8 (CCK-8) assay. Cell migration and invasion were monitored by transwell assay. The expression of Epithelial-mesenchymal transition (EMT)-related markers, including E-cadherin, α-Smooth muscle actin (α-SMA), fibronectin and β-catenin, and autophagy-related markers, including Beclin 1 and light chain 3 (LC3-II and LC3-I) at the protein level was quantified using western blot. The prediction of the relationship between LINC00028 and miR-204-5p was performed by the online tool miRcode, and the verification of the relationship between them was conducted using dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull-down assay. The expression of LINC00028 was elevated in glaucoma tissues and TGFβ1-treated HTFs. LINC00028 downregulation blocked proliferation, migration, invasion, EMT, fibrosis and autophagy of TGFβ1-treated HTFs. MiR-204-5p was a target of LINC00028, and its reintroduction exerted a similar role of LINC00028 downregulation. The inhibition of miR-204-5p reversed the effects of LINC00028 downregulation in TGFβ1-treated HTFs. LINC00028 regulated proliferation, migration, invasion, EMT, fibrosis and autophagy to induce the development of HTFs by competitively targeting miR-204-5p, and LINC00028 was regarded as a promising biomarker for glaucoma filtration treatment.

Identification of Three lncRNAs as Potential Predictive Biomarkers of Lung Adenocarcinoma

Background

Lung cancer is the most common cancer and the most common cause of cancer-related death worldwide. However, the molecular mechanism of its development is unclear. It is imperative to identify more novel biomarkers.

Methods

Two datasets (GSE70880 and GSE113852) were downloaded from the Gene Expression Omnibus (GEO) database and used to identify the differentially expressed genes (DEGs) between lung cancer tissues and normal tissues. Then, we constructed a competing endogenous RNA (ceRNA) network and a protein-protein interaction (PPI) network and performed gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and survival analyses to identify potential biomarkers that are related to the diagnosis and prognosis of lung cancer.

Results

A total of 41 lncRNAs and 805 mRNAs were differentially expressed in lung cancer. The ceRNA network contained four lncRNAs (CLDN10-AS1, SFTA1P, SRGAP3-AS2, and ADAMTS9-AS2), 21 miRNAs, and 48 mRNAs. Functional analyses revealed that the genes in the ceRNA network were mainly enriched in cell migration, transmembrane receptor, and protein kinase activity. mRNAs DLGAP5, E2F7, MCM7, RACGAP1, and RRM2 had the highest connectivity in the PPI network. Immunohistochemistry (IHC) demonstrated that mRNAs DLGAP5, MCM7, RACGAP1, and RRM2 were upregulated in lung adenocarcinoma (LUAD). Survival analyses showed that lncRNAs CLDN10-AS1, SFTA1P, and ADAMTS9-AS2 were associated with the prognosis of LUAD.

Conclusion

lncRNAs CLDN10-AS1, SFTA1P, and ADAMTS9-AS2 might be the biomarkers of LUAD. For the first time, we confirmed the important role of lncRNA CLDN10-AS1 in LUAD.

Inhibition of osteopontin overcomes acquired resistance to afatinib in EGFR-mutant non-small-cell lung cancer

Background

We aimed to explore a novel therapeutic strategy to conquer acquired resistance to second generation EGFR-TKI afatinib in EGFR-mutant NSCLC.

Methods

Firstly, we established afatinib-resistant cell lines using increasing concentrations of afatinib. Secondly, we over-expressed or silenced the expression of osteopontin (OPN) using in-vitro transfection. Further, western blot analysis was used to detect the expressions of OPN and epithelial-mesenchymal transition (EMT) biomarkers. Finally, cell proliferation was evaluated by MTT assay.

Results

Afatinib (≤5.0 µmol/L)-resistant H1650 (H1650-AR) and H1975 (H1975-AR) cells were successfully established, and grew faster compared with both parental cells at the same time interval. Western blot analysis revealed that afatinib significantly promoted the expressions of OPN and EMT biomarkers in H1975-AR and H1650-AR cells. Gain and loss assays validated that OPN over-expression promoted acquired resistance to afatinib, and induced the expressions of EMT biomarkers in H1650-AR and H1975-AR cells. Conversely, silencing of OPN not only significantly sensitized resistant cells to afatinib, but also suppressed EMT progression in H1650-AR and H1975-AR cells.

Conclusions

These results demonstrated that OPN was required for acquired resistance of EGFR-mutant NSCLC cells to afatinib.

The Polymorphisms of lncRNA HOXA11-AS and the risk of Lung Cancer in Northeastern Chinese population

Long non-coding RNAs (LncRNA) have been wildly explored in several malignant tumors. This study aimed to evaluate the effect of HOXA11-AS polymorphisms (rs17427875 and rs11564004) on lung cancer susceptibility and its interaction with smoking exposure. This hospital-based case-control study, which included 466 cases and 557 controls, was carried out in Shenyang City, Liaoning province. The genotyping method was TaqMan allelic discrimination assay and all statistical analysis were performed by SPSS 20.0 and R (3.5.3). The results demonstrated that HOXA11AS-rs17427875 polymorphisms were correlated with the susceptibility of lung adenocarcinoma. T alleles of rs17427875 played a portal role in increasing lung adenocarcinoma risk. HOXA11AS-rs11564004 polymorphisms had the significant association with lung cancer risks, as well as its subtypes like non-small cell lung cancer, adenocarcinoma. The allele G of rs11564004 acted as a protective factor for lung cancer. The similar results were observed in the homozygous model and recessive model of rs11564004. Nevertheless, interaction analysis of the additive and multiplicative model scales showed no statistical significance between HOXA11-AS polymorphisms and smoking exposure in the development of lung cancer.