A Novel Long Non-coding RNA, MSTRG.51053.2 Regulates Cisplatin Resistance by Sponging the miR-432-5p in Non-small Cell Lung Cancer Cells

Hsa-miR-665 Is a Promising Biomarker in Cancer Prognosis

Biomarkers are biomolecules used to identify or predict the presence of a specific disease or condition. They play an important role in early diagnosis and may be crucial for treatment. MicroRNAs (miRNAs), a group of small non-coding RNAs, are more and more regarded as promising biomarkers for several reasons. Dysregulation of miRNAs has been linked with development of several diseases, including many different types of cancer, and abnormal levels can be present in early stages of tumor development. Because miRNAs are stable molecules secreted and freely circulating in blood and urine, they can be sampled with little or no invasion. Here, we present an overview of the current literature, focusing on the types of cancers for which dysregulation of miR-665 has been associated with disease progression, recurrence, and/or prognosis. It needs to be emphasized that the role of miR-665 sometimes seems ambiguous, in the sense that it can be upregulated in one cancer type and downregulated in another and can even change during the progression of the same cancer. Caution is thus needed before using miR-665 as a biomarker, and extrapolation between different cancer types is not advisable. Moreover, more detailed understanding of the different roles of miR-665 will help in determining its potential as a diagnostic and prognostic biomarker.

Microsomal glutathione transferase 1 in cancer and the regulation of ferroptosis

Microsomal glutathione transferase 1 (MGST1) is a member of the MAPEG family (membrane associated proteins in eicosanoid and glutathione metabolism), defined according to enzymatic activities, sequence motifs, and structural properties. MGST1 is a homotrimer which can bind three molecules of glutathione (GSH), with one modified to a thiolate anion displaying one-third-of-sites-reactivity. MGST1 has both glutathione transferase and peroxidase activities. Each is based on stabilizing the GSH thiolate in the same active site. MGST1 is abundant in the liver and displays a broad subcellular distribution with high levels in endoplasmic reticulum and mitochondrial membranes, consistent with a physiological role in protection from reactive electrophilic intermediates and oxidative stress. In this review paper, we particularly focus on recent advances made in understanding MGST1 activation, induction, broad subcellular distribution, and the role of MGST1 in apoptosis, ferroptosis, cancer progression, and therapeutic responses.

CircNCOR1 regulates breast cancer radiotherapy efficacy by regulating CDK2 via hsa-miR-638 binding

BACKGROUND

Despite aggressive local and regional therapy, triple-negative breast cancer (TNBC) is characterized by an increased risk of locoregional recurrence. RNA-sequencing data has identified a large number of circRNAs in primary breast cancers, but the role of specific circRNAs in regulating the radiosensitivity of TNBC is not fully understood. This research aimed to investigate the function of circNCOR1 in the radiosensitivity of TNBC.

METHODS

CircRNA high-throughput sequencing was conducted on two breast cancer MDA-MB-231 and BT549 cell lines after 6 Gy radiation. The relationship between circNCOR1, hsa-miR-638, and CDK2 was determined by RNA immunoprecipitation (RIP), FISH and luciferase assays. The proliferation and apoptosis of breast cancer cells were measured by CCK8, flow cytometry, colony formation assays, and western blot.

RESULTS

Differential expression of circRNAs was closely related to the proliferation of breast cancer cells after irradiation. Overexpression of circNCOR1 facilitated the proliferation of MDA-MB-231 and BT549 cells and impaired the radiosensitivity of breast cancer cells. Additionally, circNCOR1 acted as a sponge for hsa-miR-638 to regulate the downstream target protein CDK2. Overexpression of hsa-miR-638 promoted apoptosis of breast cancer cells, while overexpression of CDK2 alleviated apoptosis and increased proliferation and clonogenicity. In vivo, overexpression of circNCOR1 partially reversed radiation-induced loosening of tumor structures and enhanced tumor cell proliferation.

CONCLUSION

Our results demonstrated that circNCOR1 bounds to hsa-miR-638 and targets CDK2, thereby regulating the radiosensitivity of TNBC.

Circ_0000395 Promoted CRC Progression via Elevating MYH9 Expression by Sequestering miR-432-5p

Colorectal cancer (CRC) has been listed as the fourth deadly cancer. Circular RNA hsa_circRNA_001046, also termed as hsa_circ_0000395 (circ_0000395), has been shown to be upregulated in CRC. Nevertheless, the function of circ_0000395 in CRC progression is unclear. 42 CRC patients were enrolled in the study. Detection of circ_0000395 expression in tissues and cells was executed using real-time quantitative polymerase chain reaction (RT-qPCR). Evaluation of circ_0000395 function was performed using loss-of-function experiments in vitro and in vivo. The regulatory mechanism of circ_0000395 was predicted by bioinformatics analysis and validated by dual-luciferase reporter and RIP assays. Exosomes were isolated by ultracentrifugation and validated by western blotting, TEM, and NTA. Circ_0000395 was strongly expressed in CRC samples and cell lines. Also, circ_0000395 repressed CRC growth in mouse models in vivo and induced CRC cell apoptosis, restrained CRC cell proliferation, migration, invasion, and EMT in vitro. Mechanistically, circ_0000395 sequestered miR-432-5p to regulate MYH9 expression. Furthermore, miR-432-5p knockdown reversed circ_0000395 silencing-mediated effects on CRC cell malignant phenotypes. MYH9 overexpression counteracted the inhibiting effects of miR-432-5p upregulation on CRC cell malignant phenotypes. Additionally, CRC cells derived from exosomal circ_0000395 promoted cancer cell malignant phenotypes. Our findings demonstrated that circ_0000395 sequestered miR-432-5p to elevate MYH9 expression, resulting in facilitating CRC progression, manifesting a potential therapeutic target for CRC.

SNPs Sets in Codifying Genes for Xenobiotics-Processing Enzymes Are Associated with COPD Secondary to Biomass-Burning Smoke

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide; the main risk factors associated with the suffering are tobacco smoking (TS) and chronic exposure to biomass-burning smoke (BBS). Different biological pathways have been associated with COPD, especially xenobiotic or drug metabolism enzymes. This research aims to identify single nucleotide polymorphisms (SNPs) profiles associated with COPD from two expositional sources: tobacco smoking and BBS. One thousand-five hundred Mexican mestizo subjects were included in the study and divided into those exposed to biomass-burning smoke and smokers. Genome-wide exome genotyping was carried out using Infinium Exome-24 kit arrays v. 1.2. Data quality control was conducted using PLINK 1.07. For clinical and demographic data analysis, Rstudio was used. Eight SNPs were found associated with COPD secondary to TS and seven SNPs were conserved when data were analyzed by genotype. When haplotype analyses were carried out, five blocks were predicted. In COPD secondary to BBS, 24 SNPs in MGST3 and CYP family genes were associated. Seven blocks of haplotypes were associated with COPD-BBS. SNPs in the ARNT2 and CYP46A1 genes are associated with COPD secondary to TS, while in the BBS comparison, SNPs in CYP2C8, CYP2C9, MGST3, and MGST1 genes were associated with increased COPD risk.

Quantification of spatial pharmacogene expression heterogeneity in breast tumors

BACKGROUND

Chemotherapeutic drug concentrations vary across different regions of tumors and this is thought to be involved in development of chemotherapy resistance. Insufficient drug delivery to some regions of the tumor may be due to spatial differences in expression of genes involved in the disposition, transport, and detoxification of drugs (pharmacogenes). Therefore, in this study, we analyzed the spatial expression of 286 pharmacogenes in six breast cancer tissues using the recently developed Visium spatial transcriptomics platform to (1) determine if these pharmacogenes are expressed heterogeneously across tumor tissue and (2) to determine which pharmacogenes have the most spatial expression heterogeneity.

METHODS AND RESULTS

The spatial transcriptomics technology sequences the transcriptome of 55 um diameter barcoded sections (spots) across a tissue sample. We analyzed spatial gene expression profiles of four biobank-sourced breast tumor samples in addition to two breast tumor sample datasets from 10× Genomics. We define heterogeneity as the interquartile range of read counts. Collectively, we identified 8887 spots in tumor regions, 3814 in stroma, 44 in lymphocytes, and 116 in normal regions based on pathologist annotation of the tissues. We showed statistically significant differences in expression of pharmacogenes in tumor regions compared to surrounding non-tumor regions. We also observed that the most heterogeneously expressed genes within tumor regions were involved in reactive oxygen species (ROS) handling and detoxification mechanisms. GPX4, GSTP1, MGST3, SOD1, CYP4Z1, CYB5R3, GSTK1, and NAT1 showed the most heterogeneous expression within tumor regions.

CONCLUSIONS

The heterogeneous expression of these pharmacogenes may have important implications for cancer therapy due to their ability to impact drug distribution and efficacy throughout the tumor. Our results suggest that chemoresistance caused by expression of GPX4, GSTP1, MGST3, and SOD1 may be intrinsic, not acquired, since the heterogeneity is not specific to chemotherapy-treated samples or cell type. Additionally, we identified candidate chemoresistance pharmacogenes that can be further tested through focused follow-up studies.

A photo-oxidation driven proximity labeling strategy enables profiling of mitochondrial proteome dynamics in living cells

Mapping the proteomic landscape of mitochondria with spatiotemporal precision plays a pivotal role in elucidating the delicate biological functions and complex relationship with other organelles in a variety of dynamic physiological processes which necessitates efficient and controllable chemical tools. We herein report a photo-oxidation driven proximity labeling strategy to profile the mitochondrial proteome by light dependence in living cells with high spatiotemporal resolution. Taking advantage of organelle-localizable organic photoactivated probes generating reactive species and nucleophilic substrates for proximal protein oxidation and trapping, mitochondrial proteins were selectively labeled by spatially limited reactions in their native environment. Integration of photo-oxidation driven proximity labeling and quantitative proteomics facilitated the plotting of the mitochondrial proteome in which up to 310 mitochondrial proteins were identified with a specificity of 64% in HeLa cells. Furthermore, mitochondrial proteome dynamics was deciphered in drug resistant Huh7 and LPS stimulated HMC3 cells which were hard-to-transfect. A number of differential proteins were quantified which were intimately linked to critical processes and provided insights into the related molecular mechanisms of drug resistance and neuroinflammation in the perspective of mitochondria. The photo-oxidation driven proximity labeling strategy offers solid technical support to a highly precise proteomic platform in time and finer space for more knowledge of subcellular biology.

linc00958/miR-185-5p/RSF-1 modulates cisplatin resistance and angiogenesis through AKT1/GSK3β/VEGFA pathway in cervical cancer

BACKGROUND

Chemoresistance is one of the major obstacles that lead to poor prognosis in cervical cancer. linc00958 was reported to be an oncogene in cervical cancer. However, its role in mediating chemoresistance remains to be revealed.

PURPOSE

To explore the regulatory mechanisms of linc00958 in cisplatin-resistant cervical cancer cells and further validate in xenograft mice.

METHODS

Online bioinformatic tools were used to conduct the pre-investigation of linc00958/miR-185-5p/RSF-1 and predict the associations between RSF-1 and AKT1/GSK3β/VEGFA in cervical cancer. RT-qPCR measured the RNA expression levels of linc00958/miR-185-5p/RSF-1 in SiHa and SiHa/DDP. Cell survival rates were evaluated by CCK8 methods after cells were exposed to differential concentrations of DDP. Dual-luciferase reporter methods were used to measure luciferase activity. Western blot measured RSF-1 protein and phosphorylated changes of AKT1/GSK3β. Immunofluorescence was employed to observe VEGFA secretion in vitro. Tube formation was applied to evaluate the in-vitro changes of angiogenesis. The SiHa/DDP cells stably transfected with pLKO-sh-NC or pLKO-sh-linc00958 plasmids, were injected into mice, establishing xenograft models. The changes in mice weight and tumor volumes were recorded. H&E staining and Immunohistochemistry (IHC) method was further performed.

RESULTS

linc00958 expression was higher in SiHa/DDP cells. High linc00958 expression was associated with low overall survival. In SiHa/DDP cells linc00958/miR-185-5p/RSF-1 axis inhibited the cellular resistance to cisplatin and suppressed VEGFA and the tube formation through AKT1/GSK3β/VEGFA pathway. The knockdown of linc00958 inhibited RSF-1 and Ki67, curbing tumor growth; it also inhibited VEGFA and CD34, decreasing angiogenesis in mice.

CONCLUSION

linc00958/miR-185-5p/RSF-1 modulates cisplatin resistance and angiogenesis through AKT1/GSK3β/VEGFA pathway in cervical cancer.

DRAIC promotes growth of breast cancer by sponging miR-432-5p to upregulate SLBP

Mounting evidence suggests that lncRNAs can exert functions in cancer progression in multiple manners. In recent years, competing endogenous RNA (ceRNA) has been widely reported in human cancers as a lncRNA-dominant molecular pathway. The current study aimed at proving the role of lncRNA downregulated RNA in cancer (DRAIC) in breast cancer (BRCA) progression. To be specific, qRT-PCR assay was conducted to measure the expression of DRAIC and other downstream target genes. It was uncovered that DRAIC was expressed at a high level in BRCA cells. Functional analyses, including CCK-8, colony formation, and EdU assays demonstrated that DRAIC depletion suppressed BRCA cell proliferation. In addition, cell apoptosis was promoted due to DRAIC knockdown. The inhibitory effect of DRAIC reduction on BRCA cell migration and invasion was proven by transwell assays. Mechanistically, DRAIC was confirmed to predominantly distribute in the cytoplasm and could interact with miR-432-5p. In addition, stem-loop binding protein (SLBP) was verified to be a downstream target of miR-432-5p and was positively regulated by DRAIC. Taken together, DRAIC sponged miR-432-5p to enhance SLBP expression, by which malignant behaviors of BRCA cells were promoted. Our findings may help to provide a promising therapeutic target for BRCA patients.

Long non-coding RNAs and exosomal lncRNAs: Potential functions in lung cancer progression, drug resistance and tumor microenvironment remodeling

Among the different kinds of tumors threatening human life, lung cancer is one that is commonly observed in both males and females. The aggressive behavior of lung cancer and interactions occurring in tumor microenvironment enhances the malignancy of this tumor. The lung tumor cells have demonstrated capacity in developing chemo- and radio-resistance. LncRNAs are a category of non-coding RNAs that do not encode proteins, but their aberrant expression is responsible for tumor development, especially lung cancer. In the present review, we focus on both lncRNAs and exosomal lncRNAs in lung cancer, and their ability in regulating proliferation and metastasis. Cell cycle progression and molecular mechanisms related to lung cancer metastasis such as EMT and MMPs are regulated by lncRNAs. LncRNAs interact with miRNAs, STAT, Wnt, EZH2, PTEN and PI3K/Akt signaling pathways to affect progression of lung cancer cells. LncRNAs demonstrate both tumor-suppressor and tumor-promoting functions in lung cancer. They can be considered as biomarkers in lung cancer and especially exosomal lncRNAs present in body fluids are potential tools for minimally invasive diagnosis. Furthermore, we discuss regulation of lncRNAs by anti-cancer drugs and genetic tools as well as the role of these factors in therapy response of lung cancer cells.

Downregulation of Circ-CEP128 Enhances the Paclitaxel Sensitivity of Cervical Cancer Through Regulating miR-432-5p/MCL1

Chemoresistance is a common problem in cancer treatment, and circular RNA (circRNA) has been found to be associated with the progression of chemoresistance in cancer. However, the role and mechanism of circRNA centrosomal protein 128 (circ-CEP128) in the chemoresistance of cervical cancer (CC) are still unclear. The expression of circ-CEP128, microRNA (miR)-432-5p, and myeloid cell leukemia-1 (MCL1) was measured by quantitative real-time PCR. The paclitaxel resistance of cells was assessed using MTT assay. Cell proliferation, apoptosis, migration, and invasion were determined using MTT assay, colony formation assay, flow cytometry, and transwell assay. The protein levels of metastasis markers and MCL1 were examined using western blot analysis. Mice xenograft models were constructed to assess the effect of circ-CEP128 silencing on CC tumor growth and paclitaxel sensitivity. The interaction between miR-432-5p and circ-CEP128 or MCL1 was confirmed by dual-luciferase reporter assay and RIP assay. Circ-CEP128 had highly expression in CC tumor tissues and cells. Silencing of circ-CEP128 could enhance the paclitaxel sensitivity of CC cells by decreasing cell growth, migration, and invasion. Also, knockdown of circ-CEP123 reduced CC tumor growth and promoted the paclitaxel sensitivity of CC tumors. MiR-432-5p was found to be sponged by circ-CEP128, and its inhibitor could reverse the promoting function of circ-CEP128 silencing on the paclitaxel sensitivity of CC cells. Additionally, MCL1 was a target of miR-432-5p, and circ-CEP128 could sponge miR-432-5p to regulate MCL1. Besides, overexpressed MCL1 also could reverse the enhancing effect of miR-432-5p on the paclitaxel sensitivity of CC cells. In conclusion, the present study showed that circ-CEP128 silencing could increase the paclitaxel sensitivity of CC by regulating the miR-432-5p/MCL1 axis.

Circular RNA FOXO3 accelerates glycolysis and improves cisplatin sensitivity in lung cancer cells via the miR-543/Foxo3 axis

Non-small cell lung cancer (NSCLC) is the most common cause of cancer-associated mortality worldwide. Our previous study revealed that circular RNA (circRNA)-FOXO3 is highly expressed in lung cancer and inhibits cell proliferation. However, to the best of our knowledge, at present, no study has focused on the specific mechanism of circRNA-FOXO3 in drug resistance. Therefore, the present study aimed to provide novel perspectives on the role of circRNA-FOXO3 in cisplatin (DDP) resistance in NSCLC. A Cell Counting Kit-8 assay was used to determine the viability of cells overexpressed with circRNA-FOXO3 and under DDP treatment. Glycolysis was analyzed by measuring glucose consumption and lactate production. The interaction of circRNA-FOXO3, microRNA 543 (miR-543) and Foxo3 was confirmed using a dual-luciferase reporter assay. It was revealed that circRNA-FOXO3 improved cell sensitivity to DDP and repressed glycolysis in DDP-sensitive and DDP-resistant NSCLC cells. Bioinformatics analysis, luciferase reporter assays, quantitative PCR and RNA pull-down assays were employed to verify the binding of circRNA-FOXO3 to miR-543. Functionally, inhibition of miR-543 could sensitize NSCLC cells to DDP, and overexpression of miR-543 at least partially abolished the circRNA-FOXO3-induced decrease in chemoresistance. Furthermore, it was revealed that Foxo3 was a direct target of miR-543. Notably, the inhibitory action of miR-543 silencing on DDP resistance and glycolysis was reversed by overexpression of Foxo3 in DDP-sensitive and DDP-resistant NSCLC cells. In conclusion, the present study demonstrated that circRNA-FOXO3 promoted DDP sensitivity in NSCLC cells by regulating the miR-543/Foxo3 axis-mediated glycolysis balance. The present findings may provide novel perspectives for the treatment of patients with NSCLC resistant to DDP.

ALDH3A1 driving tumor metastasis is mediated by p53/BAG1 in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a lethal malignancy with metastasis, a major tumor feature that predominantly correlated with progression, but the molecules that mediated tumor metastasis remain elusive. To declare the critical regulatory genes, RNA sequencing data in LUAD patients was acquired from The Cancer Genome Atlas (TCGA) and found that ALDH3A1 was distinctly highly expressed in LUAD patients with metastasis (M1) compared with those without metastasis (M0), linked to the property of cancer stem cell and epithelial-mesenchymal transition (EMT). Besides, high ALDH3A1 expression predicted a poor prognosis. Knockdown of ALDH3A1 showed decreased proliferation, migration, and invasion in A549 cell line. Furthermore, BAG1 was regulated by ALDH3A1 through p53, enhanced cell proliferation, and predicted clinical prognosis. Our findings collectively uncovered a novel mechanism that orchestrates tumor cells' metastasis, and decreasing ALDH3A1 represented a potential therapeutic target for reprogramming metastasis.

LINC01783 facilitates cell proliferation, migration and invasion in non-small cell lung cancer by targeting miR-432-5p to activate the notch pathway

Background

Non-small cell lung cancer (NSCLC) is a common malignancy around the globe. Increasing long non-coding RNAs (lncRNAs) have been confirmed to be associated with the progression of cancers, including NSCLC. Long intergenic non-protein coding RNA 1783 (LINC01783) is a novel lncRNA and its regulatory function as competing endogenous RNA (ceRNA) has not been studied in NSCLC.

Methods

RT-qPCR measured the expression level of LINC01783 in NSCLC cells. CCK-8, EdU, transwell and wound healing assays were conducted to detect cell proliferation, migration and invasion in NSCLC. The relationship between miR-432-5p and LINC01783 along with delta like 1 (DLL-1) was illustrated by RNA pull down, RIP and luciferase reporter assays.

Results

LINC01783 was found remarkably increased in NSCLC cell lines, and down-regulation of LINC01783 suppressed cell proliferation, migration and invasion. Then, we discovered Notch pathway was related to the progression of NSCLC, and DLL-1 expression was reduced by LINC01783 knockdown. Furthermore, DLL-1 overexpression could counteract the suppressive effects of LINC01783 down-regulation on the growth of NSCLC cells. MiR-432-5p was observed to be the mutual miRNA that could bind with both LINC01783 and DLL-1. Overexpression of miR-432-5p inhibited DLL-1 expression. In the rescue assays, miR-432-5p depletion offset the impacts of LINC01783 knockdown, and then DLL-1 silence recovered the influence of miR-432-5p down-regulation on NSCLC cell growth.

Conclusion

LINC01783 aggravates NSCLC cell growth by regulating Notch pathway and sponging miR-432-5p, being a potential target in the treatment for NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01912-0.

CircNEIL3 regulatory loop promotes pancreatic ductal adenocarcinoma progression via miRNA sponging and A-to-I RNA-editing

Background

A growing number of studies have focused on investigating circRNAs as crucial regulators in the progression of multiple cancer types. Nevertheless, the biological effects and underlying mechanisms of circRNAs in pancreatic ductal adenocarcinoma (PDAC) remain unclear.

Methods

Differentially expressed circRNAs between cancerous tissue and adjacent normal tissues were identified by RNA sequencing in PDAC. Subsequently, in vitro and in vivo functional experiments were performed to investigate the functional roles of circNEIL3 in PDAC tumour growth and metastasis. Furthermore, RNA pull-down, dual-luciferase reporter assays, RNA immunoprecipitation (RIP) assays, fluorescent in situ hybridization (FISH) and Sanger sequencing assays were performed to examine the circular interaction among circNEIL3, miR-432-5p and adenosine deaminases acting on RNA 1 (ADAR1).

Results

CircNEIL3 was upregulated in PDAC and promoted the progression of PDAC cells both in vitro and in vivo. Mechanistically, circNEIL3 was shown to regulate the expression of ADAR1 by sponging miR-432-5p to induce RNA editing of glioma-associated oncogene 1 (GLI1), ultimately influencing cell cycle progression and promoting epithelial-to-mesenchymal transition (EMT) in PDAC cells. Moreover, we discovered that the circNEIL3/miR-432-5p/ADAR1 axis was correlated with the PDAC clinical stage and overall survival of PDAC patients, while ADAR1 may reduce the biogenesis of circNEIL3.

Conclusions

Our findings reveal that circNEIL3 facilitates the proliferation and metastasis of PDAC through the circNEIL3/miR-432-5p/ADAR1/GLI1/cell cycle and EMT axis and that its expression is regulated by ADAR1 through a negative feedback loop. Therefore, circNEIL3 may serve as a prognostic marker and a therapeutic target for PDAC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01333-7.

Lung cancer cells and their sensitivity/resistance to cisplatin chemotherapy: Role of microRNAs and upstream mediators

Cisplatin (CP) is a well-known chemotherapeutic agent with excellent clinical effects. The anti-tumor activity of CP has been demonstrated in different cancers such as breast, cervical, reproductive, lung, brain, and prostate cancers. However, resistance of cancer cells to CP chemotherapy has led to its failure in eradication of cancer cells, and subsequent death of patients with cancer. Fortunately, much effort has been put to identify molecular pathways and mechanisms involved in CP resistance/sensitivity. It seems that microRNAs (miRs) are promising candidates in mediating CP resistance/sensitivity, since they participate in different biological aspects of cells such as proliferation, migration, angiogenesis, and differentiation. In this review, we focus on miRs and their regulation in CP chemotherapy of lung cancer, as the most malignant tumor worldwide. Oncogenic miRs trigger CP resistance in lung cancer cells via targeting various pathways such as Wnt/β-catenin, Rab6, CASP2, PTEN, and Apaf-1. In contrast, onco-suppressor miRs inhibit oncogene pathways such as STAT3 to suppress CP resistance. These topics are discussed to determine the role of miRs in CP resistance/sensitivity. We also describe the upstream modulators of miRs such as lncRNAs, circRNAs, NF-κB, SOX2 and TRIM65 and their association with CP resistance/sensitivity in lung cancer cells. Finally, the effect of anti-tumor plant-derived natural compounds on miR expression during CP sensitivity of lung cancer cells is discussed.

Cytotoxicity of glucoevatromonoside alone and in combination with chemotherapy drugs and their effects on Na+,K+-ATPase and ion channels on lung cancer cells

Cardiac glycosides (CGs) are useful drugs to treat cardiac illnesses and have potent cytotoxic and anticancer effects in cultured cells and animal models. Their receptor is the Na⁺,K⁺ ATPase, but other plasma membrane proteins might bind CGs as well. Herein, we evaluated the short- and long-lasting cytotoxic effects of the natural cardenolide glucoevatromonoside (GEV) on non-small-cell lung cancer H460 cells. We also tested GEV effects on Na⁺,K⁺ -ATPase activity and membrane currents, alone or in combination with selected chemotherapy drugs. GEV reduced viability, migration, and invasion of H460 cells spheroids. It also induced cell cycle arrest and death and reduced the clonogenic survival and cumulative population doubling. GEV inhibited Na⁺,K⁺-ATPase activity on A549 and H460 cells and purified pig kidney cells membrane. However, it showed no activity on the human red blood cell plasma membrane. Additionally, GEV triggered a Cl-mediated conductance on H460 cells without affecting the transient voltage-gated sodium current. The administration of GEV in combination with the chemotherapeutic drugs paclitaxel (PAC), cisplatin (CIS), irinotecan (IRI), and etoposide (ETO) showed synergistic antiproliferative effects, especially when combined with GEV + CIS and GEV + PAC. Taken together, our results demonstrate that GEV is a potential drug for cancer therapy because it reduces lung cancer H460 cell viability, migration, and invasion. Our results also reveal a link between the Na⁺,K⁺-ATPase and Cl^- ion channels.

The molecular mechanisms of the long noncoding RNA SBF2-AS1 in regulating the proliferation of oesophageal squamous cell carcinoma

The long noncoding RNASBF2-AS1 can promote the occurrence and development of many kinds of tumours, but its role in oesophageal squamous cell carcinoma (ESCC) is unknown. We found that SBF2-AS1 was up-regulated in ESCC, and its expression was positively correlated with tumor size (P = 0.0001), but was not related to gender, age, TNM stage, histological grade, and lymphnode metastasis (P > 0.05). It was further found that the higher the expression of SBF2-AS1, the lower the survival rate. COX multivariate analysis showed that the expression of SBF2-AS1 was an independent prognostic factor. Functional experiments show that inhibition of SBF2-AS1 can inhibit the proliferation of ESCC through in vivo and in vitro, and overexpression of SBF2-AS1 can promote the proliferation of ESCC and inhibit its apoptosis. In mechanism, SBF2-AS1/miR-338-3P, miR-362-3P/E2F1 axis are involved in the regulation of ESCC growth. In general, SBF2-AS1 may be used as ceRNA to combine with miR-338-3P and miR-362-3P to up-regulate the expression ofE2F1, and ultimately play a role in promoting cancer. It may be used as a therapeutic target and a biomarker for prognosis.

FGD5‑AS1 promotes cisplatin resistance of human lung adenocarcinoma cell via the miR‑142‑5p/PD‑L1 axis

Previous studies have reported that long non-coding (lnc) RNA FGD5-antisense 1 (FGD5-AS1) promotes tumor proliferation, migration and invasion. Therefore, the present study aimed to elucidate the biological role and underlying molecular mechanisms of FGD5-AS1 in cisplatin (DDP) resistance of lung adenocarcinoma (LAD) cells. The results demonstrated that FGD5-AS1 was highly expressed in DDP-resistant LAD tissues and cells. Knockdown of FGD5-AS1 decreased the proliferative, migratory and invasive abilities of DDP-resistant LAD cells. Moreover, it was identified that FGD5-AS1 acted as a molecular sponge for microRNA (miR)-142, and FGD5-AS1 enhanced the resistance of A549/DDP cells to DDP by directly interacting with miR-142. Programmed cell death 1 ligand 1 (PD-L1) was also found to be a key effector of the FGD5-AS1/miR-142 axis to regulate the chemoresistance of DDP-resistant LAD cells. In conclusion, the present study demonstrated that FGD5-AS1 increased DDP resistance of LAD via the miR-142/PD-L1 axis, which may offer a novel treatment strategy for patients with DDP-resistant LAD.

Development of a Novel Serum Exosomal MicroRNA Nomogram for the Preoperative Prediction of Lymph Node Metastasis in Esophageal Squamous Cell Carcinoma

Preoperative prediction of lymph node (LN) metastasis is accepted as a crucial independent risk factor for treatment decision-making for esophageal squamous cell carcinoma (ESCC) patients. Our study aimed to establish a non-invasive nomogram to identify LN metastasis preoperatively in ESCC patients. Construction of the nomogram involved three sequential phases with independent patient cohorts. In the discovery phase (N = 20), LN metastasis-associated microRNAs (miRNAs) were selected from next-generation sequencing (NGS) assay of human ESCC serum exosome samples. In the training phase (N = 178), a nomogram that incorporated exosomal miRNA model and clinicopathologic was developed by multivariate logistic regression analysis to preoperatively predict LN status. In the validation phase (n = 188), we validated the predicted nomogram's calibration, discrimination, and clinical usefulness. Four differently expressed miRNAs (chr 8-23234-3p, chr 1-17695-5p, chr 8-2743-5p, and miR-432-5p) were tested and selected in the serum exosome samples from ESCC patients who have or do not have LN metastasis. Subsequently, an optimized four-exosomal miRNA model was constructed and validated in the clinical samples, which could effectively identify ESCC patients with LN metastasis, and was significantly superior to preoperative computed tomography (CT) report. In addition, a clinical nomogram consisting of the four-exosomal miRNA model and CT report was established in training cohort, which showed high predictive value in both training and validation cohorts [area under the receiver operating characteristic curve (AUC): 0.880 and 0.869, respectively]. The Hosmer–Lemeshow test and decision curve analysis implied the nomogram's clinical applicability. Our novel non-invasive nomogram is a robust prediction tool with promising clinical potential for preoperative LN metastasis prediction of ESCC patients, especially in T1 stage.

Epitranscriptomics and epiproteomics in cancer drug resistance: therapeutic implications

Drug resistance is a major hurdle in cancer treatment and a key cause of poor prognosis. Epitranscriptomics and epiproteomics are crucial in cell proliferation, migration, invasion, and epithelial–mesenchymal transition. In recent years, epitranscriptomic and epiproteomic modification has been investigated on their roles in overcoming drug resistance. In this review article, we summarized the recent progress in overcoming cancer drug resistance in three novel aspects: (i) mRNA modification, which includes alternative splicing, A-to-I modification and mRNA methylation; (ii) noncoding RNAs modification, which involves miRNAs, lncRNAs, and circRNAs; and (iii) posttranslational modification on molecules encompasses drug inactivation/efflux, drug target modifications, DNA damage repair, cell death resistance, EMT, and metastasis. In addition, we discussed the therapeutic implications of targeting some classical chemotherapeutic drugs such as cisplatin, 5-fluorouridine, and gefitinib via these modifications. Taken together, this review highlights the importance of epitranscriptomic and epiproteomic modification in cancer drug resistance and provides new insights on potential therapeutic targets to reverse cancer drug resistance.

Down-regulation of circ-PTN suppresses cell proliferation, invasion and glycolysis in glioma by regulating miR-432-5p/RAB10 axis

BACKGROUND

Circular RNAs (circRNAs) are related to the carcinogenesis of cancers, including glioma. However, the role and mechanism of circRNA pleiotrophin (circ-PTN) remain largely unknown.

METHODS

Glioma tissues (n = 30) and normal tissues were obtained. Glioma cell lines LN229 and A172 were cultured for experiments in vitro. circ-PTN, microRNA-432-5p (miR-432-5p) and Ras-related protein Rab-10 (RAB10) levels were examined via quantitative reverse transcription polymerase chain reaction or western blot. Cell proliferation, invasion and glycolysis were examined via 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide, colony formation analysis, transwell invasion analysis, specific glucose, lactate or adenosine triphosphate assay kit and western blot. The relationship of miR-432-5p and circ-PTN or RAB10 was analyzed via dual-luciferase reporter analysis. The effect of circ-PTN on glioma development in vivo was explored by a murine xenograft model.

RESULTS

circ-PTN expression was enhanced and miR-432-5p abundance was reduced in glioma tissues and cells. circ-PTN silence suppressed cell proliferation, invasion and glycolysis. circ-PTN regulated glioma development by directly sponging miR-432-5p. RAB10 was a target of miR-432-5p and miR-432-5p inhibited cell proliferation, invasion and glycolysis by targeting RAB10. circ-PTN could modulate RAB10 expression via miR-432-5p. circ-PTN knockdown reduced glioma cell xenograft tumor growth in vivo.

CONCLUSION

circ-PTN knockdown repressed cell proliferation, invasion and glycolysis in glioma via modulating miR-432-5p and RAB10.

Lnc-HSD17B11-1:1 Functions as a Competing Endogenous RNA to Promote Colorectal Cancer Progression by Sponging miR-338-3p to Upregulate MACC1

Background

Long non-coding RNAs (lncRNAs) play pivotal roles in various kinds of human diseases, especially in cancer. However, regulatory role, clinical significance and underlying mechanisms of lncRNAs in colorectal cancer (CRC) liver metastasis still remain largely unknown. This study aimed to report a novel lncRNA, lnc-HSD17B-11:1, and its functional role in CRC progression.

Materials and methods

Differentially expressed lnc-HSD17B11-1:1 was screened and identified from a lncRNA profile microarray. Quantitative real-time PCR was used to determine the expression levels and prognostic values of lncRNA in CRC cohorts. In vitro and in vivo functional experiments were performed to investigate the effects of lnc-HSD17B11-1:1 on tumor growth and metastasis in CRC. Mechanistically, Base Scope, bioinformatics analyses, dual luciferase reporter assay and RNA immunoprecipitation experiments were performed to confirm the association of lnc-HSD17B11-1:1 and miR-338-3p. Dual luciferase reporter assay, qRT-PCR and western blot analysis were performed to assess the relationships among lnc-HSD17B11-1:1, miR-338-3p, and MACC1.

Results

Evidently up-regulation of lnc-HSD17B11-1:1 in CRC primary tissues was correlated with the depth of invasion (p = 0.043), clinical stage (p = 0.027), distant metastasis (p = 0.003) and poor prognosis of patients with CRC. lnc-HSD17B11-1:1 promoted CRC cell proliferation, mobility and invasion in vitro and in vivo. Mechanistic analysis revealed that lnc-HSD17B11-1:1 may act as a competing endogenous RNA (ceRNA) by acting as a sponge for miR-338-3p to upregulate the expression of MACC1.

Conclusion

These findings suggest that lnc-HSD17B11-1:1 promotes CRC progression through lnc-HSD17B11-1:1/miR-338-3p/MACC1 axis and this might serve as a new diagnostic marker or target for treatment of CRC.