Long non-coding RNA AFAP1-AS1 accelerates lung cancer cells migration and invasion by interacting with SNIP1 to upregulate c-Myc

Identifying cross-tissue molecular targets of lung function by multi-omics integration analysis from DNA methylation and gene expression of diverse human tissues

BACKGROUND

Previous studies have reported several genetic loci associated with lung function. However, the mediating mechanism between these genetic loci and lung function phenotype is rarely explored. In this research, we used a cross-tissue multi-omics post-GWAS analysis to explain the associations between DNA methylation, gene expression, and lung function.

METHODS

We conducted integration analyses of lung function traits using genome-wide association study (GWAS) summary data alongside expression quantitative trait loci (eQTLs) and DNA methylation quantitative trait loci (mQTLs) derived from whole blood, utilizing multi-omics SMR and Bayesian colocalization analysis. Considering the genetic differences of tissues, we replicated the shared causal signals of eQTLs and lung function in 48 diverse tissues and the shared causal signals of mQTLs and lung function in 8 diverse tissues. Multi-trait colocalization analyses were utilized to identify the causal signals between gene expression in blood, blood cell traits, and lung function, as well as between cross-tissue gene expression in diverse tissues and lung function.

RESULTS

Eight genes from blood tissue were prioritized as FEV1 causal genes using multi-omics SMR analysis and COLOC colocalization analysis: EML3, UBXN2A, ROM1, ZBTB38, RASGRP3, FAIM, PABPC4, and SNIP1. Equally, five genes (CD46, EML3, UBXN2A, ZBTB38, and LMCD1) were prioritized as FVC causal genes and one gene (LMCD1) was prioritized as FEV1/FVC causal genes. The causal signals between 8 genes (EML3, ROM1, UBXN2A, ZBTB38, RASGRP3, FAIM, PABPC4, and CD46) and lung function were successfully replicated in diverse tissues. More importantly, MOLCO colocalization analysis showed that 3 genes (CD46, LMCD1, and ZBTB38) expression in blood, blood cell traits, and lung function traits shared the same causal signals. Finally, through cross-tissue colocalization analysis of multiple traits, we found that the heart-lung axis EML3 expressions and lung function mediate the same causal signal.

CONCLUSION

This study identified potential cross-tissue molecular targets associated with lung function traits from DNA methylation and gene expression of diverse tissues and explored the probable regulation mechanism of these molecular targets. This provides multi-omics and cross-tissue evidence for the molecular regulation mechanism of lung function and may provide new insight into the influence of crosstalk between organs and tissues on lung function.

Study on the metastatic mechanism of LINC00115 in adenocarcinoma of the Esophagogastric junction

Adenocarcinoma of the esophagogastric junction (AEG) is a common and deadly cancer, and an in-depth investigation of its molecular mechanisms of metastasis is crucial for discovering new therapeutic targets. This study explores the role of the long non-coding RNA (lncRNA) LINC00115 in AEG metastasis and its underlying mechanisms. Through the analysis of 108 pairs of AEG cancer tissues and matched adjacent tissues, we found a significant upregulation of LINC00115 in AEG tissues, closely associated with TNM staging and lymph node metastasis. Utilizing cell counting kit-8 (CCK-8) assays, colony formation experiments, wound healing assays, flow cytometry for apoptosis and cell cycle analysis, and Transwell assays, we have confirmed that LINC00115 significantly promotes proliferation, migration, and invasion of AEG cells in vitro. Animal experiments further validate the role of LINC00115 in promoting tumor growth and metastasis in vivo. Additionally, our nuclear-cytoplasmic fractionation experiments and RNA fluorescence in situ hybridization (FISH) reveal that LINC00115, along with its interacting protein KH-Type splicing regulatory protein (KHSRP), predominantly localizes to the cell nucleus. By conducting RNA pull-down assays and mass spectrometry (MS) analysis, we have identified a direct interaction between LINC00115 and KHSRP protein and further determined their binding sites through catRAPID and ENCORI databases. This study provides evidence of LINC00115 as a novel biomarker and potential therapeutic target for AEG and offers a fresh perspective on understanding the molecular mechanisms of AEG metastasis.

Comparative Analysis of Transcriptomic and Proteomic Expression between Two Non-Small Cell Lung Cancer Subtypes

Non-small cell lung cancer (NSCLC) is frequently diagnosed late and has poor survival. The two predominant subtypes of NSCLC, adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC), are currently differentially diagnosed using immunohistochemical markers; however, they are increasingly recognized as very different cancer types suggestive of potential for new, more targeted therapies. There are extensive efforts to find more precise and noninvasive differential diagnostic tools. Here, we examined these two NSCLC subtypes for differences that may inform treatment and identify potential novel therapeutic pathways. We presented a comparative analysis of transcriptomic and proteomic expression in tumors from a cohort of 22 NSCLC patients: 8 LUSC and 14 LUAD. Comparing NSCLC subtypes, we found differential gene expression related to cell differentiation for LUSC and cellular structure and immune response regulation for LUAD. Differential protein expression between NSCLC subtypes was related to extracellular structure for LUSC and metabolic processes, including glucose metabolism for LUAD. This direct comparison was more informative about subtype-specific pathways than between each subtype and control (nontumor) tissues. Many of our observations between NSCLC subtypes support and inform existing observations and reveal differences that may aid research seeking to identify and validate novel subtype biomarkers or druggable targets.

Exosomal AFAP1-AS1 Promotes the Growth, Metastasis, and Glycolysis of Pituitary Adenoma by Inhibiting HuR Degradation

Exosomal long noncoding RNAs (lncRNAs), which are highly expressed in tumor-derived exosomes, regulate various cellular behaviors such as cell proliferation, metastasis, and glycolysis by facilitating intercellular communication. Here, we explored the role and regulatory mechanism of tumor-derived exosomal lncRNAs in pituitary adenomas (PA). We isolated exosomes from PA cells, and performed in vitro and in vivo assays to examine their effect on the proliferation, metastasis, and glycolysis of PA cells. In addition, we conducted RNA pull-down, RNA immunoprecipitation, co-immunoprecipitation, and ubiquitination assays to investigate the downstream mechanism of exosomal AFAP1-AS1. Exosomes from PA cells augmented the proliferation, mobility, and glycolysis of PA cells. Moreover, AFAP1-AS1 was significantly enriched in these exosomes and stimulated the growth, migration, invasion, and glycolysis of PA cells in vitro, as well as tumor metastasis in vivo. It also enhanced the binding affinity between Hu antigen R (HuR) and SMAD-specific E3 ubiquitin protein ligase 1 (SMURF1), resulting in HuR ubiquitination and degradation accompanied by enhanced expression of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). Moreover, HuR overexpression alleviated the exosomal AFAP1-AS1-mediated promotion of growth, metastasis, and glycolysis effects. These findings indicate that tumor-derived exosomal AFAP1-AS1 modulated SMURF1-mediated HuR ubiquitination and degradation to upregulate HK2 and PKM2 expression, thereby enhancing PA cell growth, metastasis, and glucose metabolism. This suggests targeting exosomal AFAP1-AS1 may be a potential strategy for the treatment of PA.

Long non-coding RNA OIP5-AS1 protects neurons from ischemia-reperfusion injury and inhibits neuronal apoptosis through TAB-2

Ischemic stroke represents a highly perilous cerebrovascular disorder, involving a variety of complex pathophysiological mechanisms. OIP5 antisense RNA 1 (OIP5-AS1) is a long non-coding RNA (LncRNA) that has been shown to play a pivotal role in a variety of disease systems. However, there are relatively few studies on ischemic stroke. This research aimed to elucidate the direct impact of OIP5-AS1 on neuronal cells following cerebral ischemia-reperfusion. Our study revealed a significant reduction in OIP5-AS1 expression in mouse neurons following middle cerebral artery occlusion/reperfusion (MCAO/R). Overexpression of OIP5-AS1 in neurons inhibits neuronal apoptosis induced by cerebral ischemia-reperfusion injury (CIRI) and exerts a neuroprotective role. Mechanistically, OIP5-AS1 may play a neuroprotective role after CIRI by up-regulating the expression of TAK1 binding protein 2 (TAB-2), reducing neuronal mitochondrial damage, and inhibiting apoptosis. OIP5-AS1 may become a novel therapeutic target for ischemic stroke.

Role of PD-1/PD-L1 signaling axis in oncogenesis and its targeting by bioactive natural compounds for cancer immunotherapy

Cancer is a global health problem and one of the leading causes of mortality. Immune checkpoint inhibitors have revolutionized the field of oncology, emerging as a powerful treatment strategy. A key pathway that has garnered considerable attention is programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1). The interaction between PD-L1 expressed on tumor cells and PD-1 reduces the innate immune response and thus compromises the capability of the body's immune system. Furthermore, it controls the phenotype and functionality of innate and adaptive immune components. A range of monoclonal antibodies, including avelumab, atezolizumab, camrelizumab, dostarlimab, durvalumab, sinitilimab, toripalimab, and zimberelimab, have been developed for targeting the interaction between PD-1 and PD-L1. These agents can induce a broad spectrum of autoimmune-like complications that may affect any organ system. Recent studies have focused on the effect of various natural compounds that inhibit immune checkpoints. This could contribute to the existing arsenal of anticancer drugs. Several bioactive natural agents have been shown to affect the PD-1/PD-L1 signaling axis, promoting tumor cell apoptosis, influencing cell proliferation, and eventually leading to tumor cell death and inhibiting cancer progression. However, there is a substantial knowledge gap regarding the role of different natural compounds targeting PD-1 in the context of cancer. Hence, this review aims to provide a common connection between PD-1/PD-L1 blockade and the anticancer effects of distinct natural molecules. Moreover, the primary focus will be on the underlying mechanism of action as well as the clinical efficacy of bioactive molecules. Current challenges along with the scope of future research directions targeting PD-1/PD-L1 interactions through natural substances are also discussed.

A Comparative Meta-Analysis on the Association of lncRNAs MALAT1, HOTAIR, and AFAP1-AS1 With the Risk of Developing Lymph Node Metastasis in Lung Cancer

BACKGROUND

Numerous studies have demonstrated the significance of long noncoding RNA (lncRNA) in the development of cancer metastasis. The expression levels of many lncRNAs are elevated in metastatic lung cancer patients compared to non-metastatic lung cancer patients.

OBJECTIVES

The primary objective of the study was to investigate the association between the expression levels of three lncRNAs (MALAT1, HOTAIR, and AFAP1-AS1) and lymph node metastasis (LNM) of lung cancer.

METHODS

Cell Press, PubMed, SpringerLink, Web of Science, and Google Scholar were explored to perform the literature search. After screening 1862 articles, 66 English-language articles were selected based on the inclusion and exclusion criteria. From those articles, 17 publications comprising 1622 lung cancer patients were chosen for statistical analyses as well as quality assessment tests.

RESULTS

Forest plot analysis revealed that there was a significant difference in the incidence of LNM between the high and low MALAT1 expression groups (OR = 3.21, 95% CI: 1.34-7.67; random effects model). Significant differences were also observed in the incidence of LNM between patients with high and low HOTAIR expression levels (OR = 4.17, 95% CI: 1.47-11.82; random effects model). The expression level of AFAP1-AS1 was found to be significantly associated with LNM in lung cancer (OR = 2.31, 95% CI: 1.39-3.85, random effects model). Additional analysis from GEPIA and GEO databases revealed that the expression levels of these lncRNAs vary according to the type of tumor tissue, organ of metastasis, and cancer stage. However, these databases show that the result for AFAP1-AS1 is the most aligned with the meta-analysis's findings. Furthermore, several quality assessment tests showed that the AFAP1-AS1 studies are more reliable compared to the studies of other lncRNAs.

CONCLUSION

This study suggested that LNM in lung cancer patients is associated mostly with an elevated AFAP1-AS1 lncRNA level among the pool of three lncRNAs analyzed. Before these results can be implemented in a clinical setting, it is essential to conduct further validation and undertake comprehensive analysis to ensure robustness and reliability.

LncRNA AFAP1-AS1 Promotes Oral Squamous Cell Carcinoma Development by Ubiquitin-Mediated Proteolysis

BACKGROUND AND PURPOSE

Long noncoding RNA (lncRNA) dysregulation has been reported to play a pivotal role in the development of cancers. In this study, we aimed to screen the key lncRNA in oral squamous cell carcinoma (OSCC) via bioinformatics analysis and further validate the function of lncRNA in vitro and in vivo.

METHODS

Bioinformatics analysis was conducted to identify differentially expressed lncRNAs between control and OSCC samples. Quantitative real-time-polymerase chain reaction was employed to detect the expression of differentially expressed lncRNAs in human tongue squamous cell carcinoma and human oral keratinocytes cell lines. The biological function of lncRNA and its mechanism were examined via the experimental assessment of the cell lines with the lncRNA overexpressed and silenced. Additionally, to further explore the function of lncRNA in the progression of OSCC, xenograft tumour mouse models were established using 25 mice (5 groups, each with 5 mice). Tumour formation was observed at 2 weeks after the cell injection, and the tumours were resected at 5 weeks post-implantation.

RESULTS

Two lncRNAs, LINC00958 and AFAP1-AS1, were found to be correlated with the prognosis of OSCC. The results of the quantitative real-time-polymerase chain reaction indicated that the 2 lncRNAs were highly expressed in OSCC. In combination with the previous literature, we found AFAP1-AS1 to be a potentially important biomarker for OSCC. Thus, we further investigated its biological function and found that AFAP1-AS1 silencing inhibited cell proliferation, migration, and invasion whereas AFAP1-AS1 overexpression reversed the effect of AFAP1-AS1 silencing (P < .05). Mechanism analysis revealed that AFAP1-AS1 regulated the development of OSCC through the ubiquitin-mediated proteolysis pathway.

CONCLUSIONS

AFAP1-AS1 is an oncogene that aggravates the development of OSCC via the ubiquitin-mediated proteolysis pathway. It also provides a novel potential therapy for OSCC.

Exploring hypoxia-induced ncRNAs as biomarkers and therapeutic targets in lung cancer

Lung cancer is a deadly disease, causing nearly 20 % of all cancer deaths globally. A key factor in lung cancer's development and resistance to treatment is hypoxia, a condition where tumor cells experience low oxygen levels. In this low-oxygen environment, special molecules called non-coding RNAs (ncRNAs) become critical players. NcRNAs, including lncRNAs, miRNAs, circRNAs, and siRNAs, control how genes function and how cells behave. Some ncRNAs, like HIF1A-AS2 and HOTAIR, are linked to the aggressive spread of lung cancer, making them potential targets for therapy. Others, like certain miRNAs, show promise as early detection tools due to their influence on tumor blood vessel formation and metabolism. This complex interplay between hypoxia and ncRNAs is crucial for understanding lung cancer. For example, circRNAs can control the activity of miRNAs, impacting how tumors respond to low oxygen. Additionally, siRNAs offer a potential strategy to overcome treatment resistance caused by hypoxia. By studying the intricate relationship between hypoxia and ncRNAs, scientists hope to uncover new biomarkers for lung cancer. This knowledge will pave the way for developing more effective and targeted treatments for this devastating disease.

Multi-stage mechanisms of tumor metastasis and therapeutic strategies

The cascade of metastasis in tumor cells, exhibiting organ-specific tendencies, may occur at numerous phases of the disease and progress under intense evolutionary pressures. Organ-specific metastasis relies on the formation of pre-metastatic niche (PMN), with diverse cell types and complex cell interactions contributing to this concept, adding a new dimension to the traditional metastasis cascade. Prior to metastatic dissemination, as orchestrators of PMN formation, primary tumor-derived extracellular vesicles prepare a fertile microenvironment for the settlement and colonization of circulating tumor cells at distant secondary sites, significantly impacting cancer progression and outcomes. Obviously, solely intervening in cancer metastatic sites passively after macrometastasis is often insufficient. Early prediction of metastasis and holistic, macro-level control represent the future directions in cancer therapy. This review emphasizes the dynamic and intricate systematic alterations that occur as cancer progresses, illustrates the immunological landscape of organ-specific PMN creation, and deepens understanding of treatment modalities pertinent to metastasis, thereby identifying some prognostic and predictive biomarkers favorable to early predict the occurrence of metastasis and design appropriate treatment combinations.

Epigenetic reader ZMYND11 noncanonical function restricts HNRNPA1-mediated stress granule formation and oncogenic activity

Epigenetic readers frequently affect gene regulation, correlate with disease prognosis, and hold significant potential as therapeutic targets for cancer. Zinc finger MYND-type containing 11 (ZMYND11) is notably recognized for reading the epigenetic marker H3.3K36me3; however, its broader functions and mechanisms of action in cancer remain underexplored. Here, we report that ZMYND11 downregulation is prevalent across various cancers and profoundly correlates with poorer outcomes in prostate cancer patients. Depletion of ZMYND11 promotes tumor cell growth, migration, and invasion in vitro, as well as tumor formation and metastasis in vivo. Mechanistically, we discover that ZMYND11 exhibits tumor suppressive roles by recognizing arginine-194-methylated HNRNPA1 dependent on its MYND domain, thereby retaining HNRNPA1 in the nucleus and preventing the formation of stress granules in the cytoplasm. Furthermore, ZMYND11 counteracts the HNRNPA1-driven increase in the PKM2/PKM1 ratio, thus mitigating the aggressive tumor phenotype promoted by PKM2. Remarkably, ZMYND11 recognition of HNRNPA1 can be disrupted by pharmaceutical inhibition of the arginine methyltransferase PRMT5. Tumors with low ZMYND11 expression show sensitivity to PRMT5 inhibitors. Taken together, our findings uncover a previously unexplored noncanonical role of ZMYND11 as a nonhistone methylation reader and underscore the critical importance of arginine methylation in the ZMYND11-HNRNPA1 interaction for restraining tumor progression, thereby proposing novel therapeutic targets and potential biomarkers for cancer treatment.

Sequence-to-expression approach to identify etiological non-coding DNA variations in P53 and cMYC-driven diseases

Disease risk prediction based on genomic sequence and transcriptional profile can improve disease screening and prevention. Despite identifying many disease-associated DNA variants, distinguishing deleterious non-coding DNA variations remains poor for most common diseases. In this study, we designed in vitro experiments to uncover the significance of occupancy and competitive binding between P53 and cMYC on common target genes. Analyzing publicly available ChIP-seq data for P53 and cMYC in embryonic stem cells showed that ~344-366 regions are co-occupied, and on average, two cis-overlapping motifs (CisOMs) per region were identified, suggesting that co-occupancy is evolutionarily conserved. Using U2OS and Raji cells untreated and treated with doxorubicin to increase P53 protein level while potentially reducing cMYC level, ChIP-seq analysis illustrated that around 16 to 922 genomic regions were co-occupied by P53 and cMYC, and substitutions of cMYC signals by P53 were detected post doxorubicin treatment. Around 187 expressed genes near co-occupied regions were altered at mRNA level according to RNA-seq data analysis. We utilized a computational motif-matching approach to illustrate that changes in predicted P53 binding affinity in CisOMs of co-occupied elements significantly correlate with alterations in reporter gene expression. We performed a similar analysis using SNPs mapped in CisOMs for P53 and cMYC from ChIP-seq data, and expression of target genes from GTEx portal. We found significant correlation between change in cMYC-motif binding affinity in CisOMs and altered expression. Our study brings us closer to developing a generally applicable approach to filter etiological non-coding variations associated with common diseases.

ARMCX1 inhibits lung adenocarcinoma progression by recruiting FBXW7 for c-Myc degradation

BACKGROUND

Armadillo Repeat Containing X-Linked 1 (ARMCX1), a member of the ARM Repeat X-linked protein family, exerts inhibitory function in various tumors. However, its biological role in lung adenocarcinoma (LUAD) and the underlying molecular mechanisms require further exploration.

METHODS

LUAD tissue microarrays and bioinformatic databases were used to evaluate the relationship between ARMCX1 and clinicopathological features. The influence of ARMCX1 on LUAD cell proliferation, migration, and invasion in vitro was determined by colony formation, CCK-8, EdU incorporation, cell cycle, wound healing, and Transwell assays. The impact of ARMCX1 on LUAD cell growth and metastasis in vivo was determined by subcutaneously transplanted tumor and pulmonary metastasis assays. Western blot, immunoprecipitation, immunofluorescence, cycloheximide, and proteasome inhibitor assays were finally conducted to explore the potential underlying molecular mechanisms.

RESULTS

ARMCX1 expression was downregulated in clinical LUAD samples due to which patient prognoses were poor. Functional experiments indicated that ARMCX1 overexpression inhibited the growth and metastasis of LUAD cells in vitro and in vivo. The molecular mechanism suggested that ARMCX1 recruits the E3 ubiquitin ligase FBXW7 for mediating ubiquitinated degradation of c-Myc, suppressing its nuclear accumulation, and ultimately inactivating cell cycle and epithelial-mesenchymal transition (EMT) signals.

CONCLUSION

ARMCX1 inhibits LUAD cell proliferation and metastasis by interacting with c-Myc and enhancing its ubiquitination and degradation. Consequently, it can act as a tumor suppressor in this disease. These results suggest that ARMCX1 is a potential target in the treatment of LUAD.

Targeting circ-0034880-enriched tumor extracellular vesicles to impede SPP1highCD206+ pro-tumor macrophages mediated pre-metastatic niche formation in colorectal cancer liver metastasis

BACKGROUND

Information transmission between primary tumor cells and immunocytes or stromal cells in distal organs is a critical factor in the formation of pre-metastatic niche (PMN). Understanding this mechanism is essential for developing effective therapeutic strategy against tumor metastasis. Our study aims to prove the hypothesis that circ-0034880-enriched tumor-derived extracellular vesicles (TEVs) mediate the formation of PMN and colorectal cancer liver metastasis (CRLM), and targeting circ-0034880-enriched TEVs might be an effective therapeutic strategy against PMN formation and CRLM.

METHODS

We utilized qPCR and FISH to measure circRNAs expression levels in human CRC plasma, primary CRC tissues, and liver metastatic tissues. Additionally, we employed immunofluorescence, RNA sequencing, and in vivo experiments to assess the effect mechanism of circ-0034880-enriched TEVs on PMN formation and CRC metastasis. DARTS, CETSA and computational docking modeling were applied to explore the pharmacological effects of Ginsenoside Rb1 in impeding PMN formation.

RESULTS

We found that circ-0034880 was highly enriched in plasma extracellular vesicles (EVs) derived from CRC patients and closely associated with CRLM. Functionally, circ-0034880-enriched TEVs entered the liver tissues and were absorbed by macrophages in the liver through bloodstream. Mechanically, TEVs-released circ-0034880 enhanced the activation of SPP1highCD206+ pro-tumor macrophages, reshaping the metastasis-supportive host stromal microenvironment and promoting overt metastasis. Importantly, our mechanistic findings led us to discover that the natural product Ginsenoside Rb1 impeded the activation of SPP1highCD206+ pro-tumor macrophages by reducing circ-0034880 biogenesis, thereby suppressing PMN formation and inhibiting CRLM.

CONCLUSIONS

Circ-0034880-enriched TEVs facilitate strong interaction between primary tumor cells and SPP1highCD206+ pro-tumor macrophages, promoting PMN formation and CRLM. These findings suggest the potential of using Ginsenoside Rb1 as an alternative therapeutic agent to reshape PMN formation and prevent CRLM.

Reciprocal interactions between lncRNAs and MYC in colorectal cancer: partners in crime

Proto-oncogenic MYC is frequently dysregulated in colorectal cancer (CRC). In the past decades, long noncoding RNAs (lncRNAs) have emerged as important regulators in cancers, acting as scaffolds, molecular decoys, post-transcriptional regulators, and others. Interestingly, lncRNAs are able to control MYC expression both at transcriptional and post-transcriptional levels. It is suggested that the reciprocal interaction of MYC and lncRNAs often occurs in CRC. MYC can affect the cell fate by promoting or inhibiting the transcription of some lncRNAs. At the same time, some lncRNAs can also affect MYC expression or transcriptional activity, and in turn decide the cell fate. In this review we summarized the current knowledge about the MYC and lncRNA axis, focusing on its mutual regulation, roles in CRC, and proposed potential therapeutic prospects for CRC treatment.

Lowering expression of Epsin-3 inhibits migration and invasion of lung adenocarcinoma cells by inhibiting the epithelial-mesenchymal transition

The epithelial-mesenchymal transition (EMT) is a genetic reprogramming that tumor cells utilize for metastasis. Epsin-3 (EPN3) is an endocytic adapter protein involved in clathrin-mediated endocytosis and had been previously linked to EMT in breast cancer and glioma metastasis. In this study, identified the role of epsin-3 in lung adenocarcinoma and metastasis and epsin-3 levels identified using an expression profile analysis of patient data indicated the protein was abnormally overexpressed in lung adenocarcinoma patients and this was directly linked to disease severity. Gene knockdowns of EPN3 in human adenocarcinoma cell line A549 and the non-small cell lung carcinoma cell line H1299 decreased the levels of mesenchymal markers, including vimentin (VIM), N-cadherin (NCAD) and embryonic transcription factors like zinc finger E-box binding homeobox 1(ZEB1), snail, and the key molecules of Wnt pathway such as β-catenin and resulted in increased expression of the epithelial marker E-cadherin (ECAD). Our data links EPN3 to the EMT process in lung cancer and inhibition of its expression reduced the metastatic and invasive ability of lung adenocarcinoma cells by inhibiting the EMT process.

[Overexpression of CDHR2 inhibits proliferation of breast cancer cells by inhibiting the PI3K/Akt pathway]

OBJECTIVE

To investigate the mechanism by which CDHR2 overexpression inhibits breast cancer cell growth and cell cycle pragression via the PI3K/Akt signaling pathway.

METHODS

Bioinformatic analysis was performed to investigate CDHR2 expression in breast cancer and its correlation with survival outcomes of the patients. Immunohistochemistry was used to examine CDHR2 expressions in surgical specimens of tumor and adjacent tissues from 10 patients with breast cancer. CDHR2 expression levels were also detected in 5 breast cancer cell lines and a normal human mammary epithelial cell line using qRT-PCR and Western blotting. Breast cancer cell lines MDA-MB-231 and MCF7 with low CDHR2 expression were transfected with a CDHR2-overexpressing plasmid, and the changes in cell proliferation and cell cycle were evaluated using CCK-8 assay, EdU assay, and cell cycle assay; the changes in expressions of PI3K/Akt signaling pathway and cell cycle pathway proteins were detected with Western blotting.

RESULTS

Bioinformatic analysis showed low CDHR2 expression level in both breast cancer and adjacent tissues without significant difference between them (P > 0.05), but breast cancer patients with a high expression of CDHR2 had a more favorable prognosis. Immunohistochemistry, qRT-PCR and Western blotting showed that the expression of CDHR2 was significantly down-regulated in breast cancer tissues and breast cancer cells (P < 0.01), and its overexpression strongly inhibited cell proliferation, caused cell cycle arrest, and significantly inhibited PI3K and Akt phosphorylation and the expression of cyclin D1.

CONCLUSION

Overexpression of CDHR2 inhibits proliferation and causes cell cycle arrest in breast cancer cells possibly by inhibiting the PI3K/Akt signaling pathway.

System analysis based on Anoikis-related genes identifies MAPK1 as a novel therapy target for osteosarcoma with neoadjuvant chemotherapy

BACKGROUND

Osteosarcoma (OS) is the most common bone malignant tumor in children, and its prognosis is often poor. Anoikis is a unique mode of cell death.However, the effects of Anoikis in OS remain unexplored.

METHOD

Differential analysis of Anoikis-related genes was performed based on the metastatic and non-metastatic groups. Then LASSO logistic regression and SVM-RFE algorithms were applied to screen out the characteristic genes. Later, Univariate and multivariate Cox regression was conducted to identify prognostic genes and further develop the Anoikis-based risk score. In addition, correlation analysis was performed to analyze the relationship between tumor microenvironment, drug sensitivity, and prognostic models.

RESULTS

We established novel Anoikis-related subgroups and developed a prognostic model based on three Anoikis-related genes (MAPK1, MYC, and EDIL3). The survival and ROC analysis results showed that the prognostic model was reliable. Besides, the results of single-cell sequencing analysis suggested that the three prognostic genes were closely related to immune cell infiltration. Subsequently, aberrant expression of two prognostic genes was identified in osteosarcoma cells. Nilotinib can promote the apoptosis of osteosarcoma cells and down-regulate the expression of MAPK1.

CONCLUSIONS

We developed a novel Anoikis-related risk score model, which can assist clinicians in evaluating the prognosis of osteosarcoma patients in clinical practice. Analysis of the tumor immune microenvironment and chemotherapeutic drug sensitivity can provide necessary insights into subsequent mechanisms. MAPK1 may be a valuable therapeutic target for neoadjuvant chemotherapy in osteosarcoma.

LncRNA CARD8-AS1 suppresses lung adenocarcinoma progression by enhancing TRIM25-mediated ubiquitination of TXNRD1

Long non-coding RNAs (lncRNAs) play crucial roles in the tumorigenesis and progression of lung adenocarcinoma (LUAD). However, little was known about the role of lncRNAs in high-risk LUAD subtypes: micropapillary-predominant adenocarcinoma (MPA) and solid-predominant adenocarcinoma (SPA). In this study, we conducted a systematic screening of differentially expressed lncRNAs using RNA sequencing in 10 paired MPA/SPA tumor tissues and adjacent normal tissues. Consequently, 110 significantly up-regulated lncRNAs and 288 aberrantly down-regulated lncRNAs were identified (|Log2 Foldchange| ≥ 1 and corrected P < 0.05). The top 10 lncRNAs were further analyzed in 89 MPA/SPA tumor tissues and 59 normal tissues from The Cancer Genome Atlas database. Among them, CARD8-AS1 showed the most significant differential expression, and decreased expression of CARD8-AS1 was significantly associated with a poorer prognosis. Functionally, CARD8-AS1 overexpression remarkably suppressed the proliferation, migration and invasion of LUAD cells both in vitro and in vivo. Conversely, inhibition of CARD8-AS1 yielded opposite effects. Mechanistically, CARD8-AS1 acted as a scaffold to facilitate the interaction between TXNRD1 and E3 ubiquitin ligase TRIM25, thereby promoting the degradation of TXNRD1 through the ubiquitin-proteasome pathway. Additionally, TXNRD1 was found to promote LUAD cell proliferation, migration and invasion in vitro. Furthermore, the suppressed progression of LUAD cells resulting from CARD8-AS1 overexpression could be significantly reversed by simultaneous overexpression of TXNRD1. In conclusion, this study revealed that the lncRNA CARD8-AS1 played a suppressive role in the progression of LUAD by enhancing TRIM25-mediated ubiquitination of TXNRD1. The CARD8-AS1-TRIM25-TXNRD1 axis may represent a promising therapeutic target for LUAD.

The clinical utilization of SNIP1 and its pathophysiological mechanisms in disease

Smad intranuclear binding protein 1 (SNIP1), a highly conserved nuclear protein, functions as a transcriptional regulator and exerts a significant influence on disease progression. In addition, the N-terminal domain of SNIP1 facilitates its interaction with Smad4, a signaling protein associated with the TGF-β family, and RelA/p65, a transcription factor connected to NF-κB. This interaction further enhances the transcriptional activation of c-Myc-dependent genes. Presently, the primary emphasis in research is directed towards targeting the catalytic domain of SNIP1, as it holds promise as a potential therapeutic target for various diseases. While the significance of SNIP1 in pathological mechanisms remains uncertain, this review aims to comprehensively examine the existing literature on the association between SNIP1 and proteins implicated in the regulation of diverse clinical conditions, including cancer, inflammation, and related diseases.

Lung adenocarcinoma identification based on hybrid feature selections and attentional convolutional neural networks

Lung adenocarcinoma, a chronic non-small cell lung cancer, needs to be detected early. Tumor gene expression data analysis is effective for early detection, yet its challenges lie in a small sample size, high dimensionality, and multi-noise characteristics. In this study, we propose a lung adenocarcinoma convolutional neural network (LATCNN), a deep learning model tailored for accurate lung adenocarcinoma prediction and identification of key genes. During the feature selection stage, we introduce a hybrid algorithm. Initially, the fast correlation-based filter (FCBF) algorithm swiftly filters out irrelevant features, followed by applying the k-means-synthetic minority over-sampling technique (k-means-SMOTE) method to address category imbalance. Subsequently, we enhance the particle swarm optimization (PSO) algorithm by incorporating fast-decay dynamic inertia weights and utilizing the classification and regression tree (CART) as the fitness function for the second stage of feature selection, aiming to further eliminate redundant features. In the classifier construction stage, we present an attention convolutional neural network (atCNN) that incorporates an attention mechanism. This improved model conducts feature selection post lung adenocarcinoma gene expression data analysis for classification and prediction. The results show that LATCNN effectively reduces the feature dimensions and accurately identifies 12 key genes with accuracy, recall, F1 score, and MCC of 99.70%, 99.33%, 99.98%, and 98.67%, respectively. These performance metrics surpass those of other comparative models, highlighting the significance of this research for advancing lung adenocarcinoma treatment.

Lysine demethylase 5C inhibits transcription of prefoldin subunit 5 to activate c-Myc signal transduction and colorectal cancer progression

BACKGROUND

Lysine demethylase 5C (KDM5C) has been implicated in the development of several human cancers. This study aims to investigate the role of KDM5C in the progression of colorectal cancer (CRC) and explore the associated molecular mechanism.

METHODS

Bioinformatics tools were employed to predict the target genes of KDM5C in CRC. The expression levels of KDM5C and prefoldin subunit 5 (PFDN5) in CRC cells were determined by RT-qPCR and western blot assays. The interaction between KDM5C, H3K4me3, and PFDN5 was validated by chromatin immunoprecipitation. Expression and prognostic values of KDM5C and PFDN5 in CRC were analyzed in a cohort of 72 patients. The function of KDM5C/PFDN5 in c-Myc signal transduction was analyzed by luciferase assay. Silencing of KDM5C and PFDN5 was induced in CRC cell lines to analyze the cell malignant phenotype in vitro and tumorigenic activity in nude mice.

RESULTS

KDM5C exhibited high expression, while PFDN5 displayed low expression in CRC cells and clinical CRC samples. High KDM5C levels correlated with poor survival and unfavorable clinical presentation, whereas elevated PFDN5 correlated with improved patient outcomes. KDM5C mediated demethylation of H3K4me3 on the PFDN5 promoter, suppressing its transcription and thereby enhancing the transcriptional activity of c-Myc. KDM5C knockdown in CRC cells suppressed cell proliferation, migration and invasion, epithelial-mesenchymal transition, and tumorigenic activity while increasing autophagy and apoptosis rates. However, the malignant behavior of cells was restored by the further silencing of PFDN5.

CONCLUSION

This study demonstrates that KDM5C inhibits PFDN5 transcription, thereby activating c-Myc signal transduction and promoting CRC progression.

Comprehensive landscape and future perspective of long noncoding RNAs in non-small cell lung cancer: it takes a village

Long noncoding RNAs (lncRNAs) are a distinct subtype of RNA that lack protein-coding capacity but exert significant influence on various cellular processes. In non-small cell lung cancer (NSCLC), dysregulated lncRNAs act as either oncogenes or tumor suppressors, contributing to tumorigenesis and tumor progression. LncRNAs directly modulate gene expression, act as competitive endogenous RNAs by interacting with microRNAs or proteins, and associate with RNA binding proteins. Moreover, lncRNAs can reshape the tumor immune microenvironment and influence cellular metabolism, cancer cell stemness, and angiogenesis by engaging various signaling pathways. Notably, lncRNAs have shown great potential as diagnostic or prognostic biomarkers in liquid biopsies and therapeutic strategies for NSCLC. This comprehensive review elucidates the significant roles and diverse mechanisms of lncRNAs in NSCLC. Furthermore, we provide insights into the clinical relevance, current research progress, limitations, innovative research approaches, and future perspectives for targeting lncRNAs in NSCLC. By summarizing the existing knowledge and advancements, we aim to enhance the understanding of the pivotal roles played by lncRNAs in NSCLC and stimulate further research in this field. Ultimately, unraveling the complex network of lncRNA-mediated regulatory mechanisms in NSCLC could potentially lead to the development of novel diagnostic tools and therapeutic strategies.

MIOX inhibits autophagy to regulate the ROS -driven inhibition of STAT3/c-Myc-mediated epithelial-mesenchymal transition in clear cell renal cell carcinoma

The specific mechanism of clear cell renal cell carcinoma (ccRCC) progression, a pathological type that accounts for the highest proportion of RCC, remains unclear. In this study, bioinformatics analysis of scRNA-seq dataset in ccRCC revealed that MIOX was a gene specifically down-regulated in tumor epithelial cells of ccRCC. Analysis of the TCGA database further validated the association between decreased MIOX mRNA levels and ccRCC malignant phenotype and poor prognosis. Immunohistochemistry indicated the down-regulation of MIOX in ccRCC tissues compared to paired adjacent renal tissues, with further down-regulation of MIOX in the primary tumors of patients with primary metastasis compared to those without metastasis. Also, patients with low expression of MIOX showed shorter metastasis-free survival (MFS) compared to those with high MIOX expression. In vitro results showed that overexpression of MIOX in ccRCC cells inhibited the proliferation, migration and invasion and promoted apoptosis. Mechanistically, up-regulation of MIOX inhibited autophagy to elevate the levels of ROS, and thus suppressed STAT3/c-Myc-mediated epithelial-mesenchymal transition in ccRCC cells. In vivo data further confirmed that increased MIOX expression suppressed the growth and proliferation of RCC cells and reduced the ability of RCC cells to form metastases in the lung. This study demonstrates that MIOX is an important regulatory molecule of ccRCC, which is conducive to understanding the potential molecular mechanism of ccRCC progression.

Lnc AC016727.1/BACH1/HIF-1 α signal loop promotes the progression of non-small cell lung cancer

BACKGROUND

Long noncoding RNAs (lncRNAs) have been reported to play vital roles in the development and progression of cancer. However, their biological significance and functional mechanisms in non-small cell lung cancer (NSCLC) are mostly unclear.

METHODS

We performed RNA-sequencing to predict the differential expression of lncRNAs in clinical NSCLC and paired paracancerous lung tissues. To identify lncRNA expression, quantitative polymerase chain reaction (qPCR) was used. Using both cell and mouse models, We studied lncRNA AC016727.1's function in NSCLC growth and metastasis. Western blot assays, dual luciferase reporter assays, and chromatin immunoprecipitation were used to analyze the functional mechanism of lncRNA AC016727.1.

RESULTS

Our larger NSCLC cohorts validated that the lncRNA AC016727.1 was upregulated in 94 paired NSCLC tissues and correlated with poor survival. Functionally, lncRNA AC016727.1 downregulation inhibited NSCLC cell proliferation, aerobic glycolysis, EMT, and migration, inducing apoptosis. Conversely, upregulated lncRNA AC016727.1 expression exhibited the opposite effect, promoting NSCLC cell survival. Importantly, lncRNA AC016727.1 knockdown inhibited lung cancer growth and slowed the progression of lung metastasis in nude mouse models. Mechanistically, lncRNA AC016727.1 upregulated BACH1 target gene expression by acting as a sponge for miR-98-5p, thereby functioning as a competing endogenous RNA. The function of lncRNA AC016727.1 is mediated by the miR-98-5p/BACH1 axis in NSCLC cells. Meanwhile, the transcription factor HIF-1α can bind to the promoter and activate lncRNA AC016727.1 transcription. lncRNA AC016727.1 regulates HIF-1α expression via BACH1 in NSCLC and forms the lncRNA AC016727.1/BACH1/HIF-1α signaling loop under hypoxic conditions.

CONCLUSION

Our study reveals a novel lncRNA AC016727.1/BACH1/HIF-1α signaling loop in the progression of NSCLC under hypoxic conditions, suggesting that lncRNA AC016727.1 could act as a useful biomarker for NSCLC and a new therapeutic target.

Metastasis-Related Signature for Clinically Predicting Prognosis and Tumor Immune Microenvironment of Osteosarcoma Patients

Osteosarcoma is the most prevalent clinical malignant bone tumor in adolescents. The prognosis of metastatic osteosarcoma is still very poor. The aim of our study was to investigate the clinical diagnosis and prognostic significance of metastasis related genes (MRGs) in patients with osteosarcoma. Clinical information and RNA sequencing data with osteosarcoma patients were obtained and set as the training set from UCSC databases. GSE21257 were downloaded and chosen as the verification cohort. An eight gene metastasis related risk signature including MYC, TAC4, ABCA4, GADD45GIP1, TNFRSF21, HERC5, MAGEA11, and PDE1B was built to predict the overall survival of osteosarcoma patients. Based on risk assessments, patients were classified into high- and low-risk groups. The high-risk patients had higher risk score and shorter survival time. ROC curves revealed that this risk signature can accurately predict survival times of osteosarcoma patients at the 1-, 2-, 3-, 4- and 5- year. GSEA revealed that MYC targets, E2F targets, mTORC1 signaling, Wnt /β-catenin signaling and cell cycle were upregulated, and cell adhesion molecules, and primary immunodeficiency were decreased in high-risk group. MRGs were highly linked with the tumor immune microenvironment and ICB response. These results identified that MRGs as a novel prognostic and diagnostic biomarker in osteosarcoma.

Long noncoding RNA study: Genome-wide approaches

Long noncoding RNAs (lncRNAs) have been confirmed to play a crucial role in various biological processes across several species. Though many efforts have been devoted to the expansion of the lncRNAs landscape, much about lncRNAs is still unknown due to their great complexity. The development of high-throughput technologies and the constantly improved bioinformatic methods have resulted in a rapid expansion of lncRNA research and relevant databases. In this review, we introduced genome-wide research of lncRNAs in three parts: (i) novel lncRNA identification by high-throughput sequencing and computational pipelines; (ii) functional characterization of lncRNAs by expression atlas profiling, genome-scale screening, and the research of cancer-related lncRNAs; (iii) mechanism research by large-scale experimental technologies and computational analysis. Besides, primary experimental methods and bioinformatic pipelines related to these three parts are summarized. This review aimed to provide a comprehensive and systemic overview of lncRNA genome-wide research strategies and indicate a genome-wide lncRNA research system.

LncRNA BCAN-AS1 stabilizes c-Myc via N6-methyladenosine-mediated binding with SNIP1 to promote pancreatic cancer

C-Myc overexpression contributes to multiple hallmarks of human cancer but directly targeting c-Myc is challenging. Identification of key factors involved in c-Myc dysregulation is of great significance to develop potential indirect targets for c-Myc. Herein, a collection of long non-coding RNAs (lncRNAs) interacted with c-Myc is detected in pancreatic ductal adenocarcinoma (PDAC) cells. Among them, lncRNA BCAN-AS1 is identified as the one with highest c-Myc binding enrichment. BCAN-AS1 was abnormally elevated in PDAC tumors and high BCAN-AS1 level was significantly associated with poor prognosis. Mechanistically, Smad nuclear-interacting protein 1 (SNIP1) was characterized as a new N6-methyladenosine (m6A) mediator binding to BCAN-AS1 via recognizing its m6A modification. m6A-modified BCAN-AS1 acts as a scaffold to facilitate the formation of a ternary complex together with c-Myc and SNIP1, thereby blocking S phase kinase-associated protein 2 (SKP2)-mediated c-Myc ubiquitination and degradation. Biologically, BCAN-AS1 promotes malignant phenotypes of PDAC in vitro and in vivo. Treatment of metastasis xenograft and patient-derived xenograft mouse models with in vivo-optimized antisense oligonucleotide of BCAN-AS1 effectively represses tumor growth and metastasis. These findings shed light on the pro-tumorigenic role of BCAN-AS1 and provide an innovant insight into c-Myc-interacted lncRNA in PDAC.

Upregulation of LINC00501 by H3K27 acetylation facilitates gastric cancer metastasis through activating epithelial-mesenchymal transition and angiogenesis

BACKGROUND

The molecular mechanism of the significant role of long noncoding RNAs (lncRNAs) in the progression and metastasis of gastric cancer (GC) remains largely elusive. Our objective is to detect overexpressed lncRNA in GC and investigate its role in promoting epithelial-mesenchymal transition and tumour microenvironment remodel.

METHODS

LncRNA differential expression profile in GC was analysed using RNA microarrays. The level of LINC00501 was evaluated in both GC patient tissues and GC cell lines by quantitative reverse transcription PCR and large-scale (n = 304) tissue microarray. To explore the biological role and regulatory driver of LINC00501 in GC, various experimental techniques including Chromatin isolation by RNA purification (ChIRP), RNA immunoprecipitation (RIP), chromatin immunoprecipitation (ChIP) assay, dual luciferase assays were performed.

RESULTS

Clinically, it was observed that LINC00501 level was abnormal overexpression in GC tissue and was associated with GC progression and distant metastasis. Gain and loss molecular biological experiments suggested that LINC00501, promoted EMT process and angiogenesis of GC. Mechanically, the enrichment of H3K27 acetylation in LINC00501 promoter region contributed to the increase of LINC00501 in GC. LINC00501 transactivated transcription of SLUG, by recruiting hnRNPR to its promoter. The growth of GC was inhibited both in vitro and in vivo by suppressing the level of LINC00501 using pharmacological intervention from the histone acetyltransferase (HAT) inhibitor -C646.

CONCLUSIONS

This study suggests that LINC00501 promotes GC progression via hnRNPR/SLUG pathway, which indicates a promising biomarker and target for GC.

LncRNA RP11-58O9.2 predicts poor prognosis and promotes progression of non-small cell lung cancer

OBJECTIVE

Long non-coding RNAs (lncRNAs) play a crucial role in non-small cell lung cancer (NSCLC). This study aimed to investigate the novel biomarker, lncRNA RP11-58O9.2, in patients with NSCLC.

METHODS

RP11-58O9.2 expression in NSCLC cells and tissues was detected by reverse transcription-quantitative polymerase chain reaction. Patient survival was analyzed in relation to RP11-58O9.2 expression levels. RP11-58O9.2 expression was knocked down and endogenous expression was verified in two NSCLC cell lines. Cell proliferation was then assessed by Cell Counting Kit-8 and colony-formation assays, and cell invasion and migration were assessed by Transwell and wound-healing assays, respectively. In vivo experiments were performed in mice, and the combination of RP11-58O9.2 and miR-6749-3p was predicted by miRanda.

RESULTS

RP11-58O9.2 was highly expressed in NSCLC cell lines and tissues, and was associated with advanced stage, lymphatic metastasis, and differentiation group. High RP11-58O9.2 levels were also associated with shorter survival. RP11-58O9.2 knockdown inhibited the proliferation, invasion, and migration of lung cancer cells, and tumor growth in mouse xenografts in vivo. RP11-58O9.2 may target and regulate miR-6749-3p.

CONCLUSIONS

LncRNA RP11-58O9.2 is associated with NSCLC prognosis and promotes lung cancer progression. Further studies are needed to investigate the mechanisms and the regulatory association between RP11-58O9.2 and miR-6749-3p.

The roles of protein ubiquitination in tumorigenesis and targeted drug discovery in lung cancer

The malignant lung cancer has a high morbidity rate and very poor 5-year survival rate. About 80% - 90% of protein degradation in human cells is occurred through the ubiquitination enzyme pathway. Ubiquitin ligase (E3) with high specificity plays a crucial role in the ubiquitination process of the target protein, which usually occurs at a lysine residue in a substrate protein. Different ubiquitination forms have different effects on the target proteins. Multiple short chains of ubiquitination residues modify substrate proteins, which are favorable signals for protein degradation. The dynamic balance adapted to physiological needs between ubiquitination and deubiquitination of intracellular proteins is beneficial to the health of the organism. Ubiquitination of proteins has an impact on many biological pathways, and imbalances in these pathways lead to diseases including lung cancer. Ubiquitination of tumor suppressor protein factors or deubiquitination of tumor carcinogen protein factors often lead to the progression of lung cancer. Ubiquitin proteasome system (UPS) is a treasure house for research and development of new cancer drugs for lung cancer, especially targeting proteasome and E3s. The ubiquitination and degradation of oncogene proteins with precise targeting may provide a bright prospect for drug development in lung cancer; Especially proteolytic targeted chimerism (PROTAC)-induced protein degradation technology will offer a new strategy in the discovery and development of new drugs for lung cancer.

Role of c-Myc in lung cancer: Progress, challenges, and prospects

Lung cancer remains the leading cause of cancer-related deaths worldwide. Despite the recent advances in cancer therapies, the 5-year survival of non-small cell lung cancer (NSCLC) patients hovers around 20%. Inherent and acquired resistance to therapies (including radiation, chemotherapies, targeted drugs, and combination therapies) has become a significant obstacle in the successful treatment of NSCLC. c-Myc, one of the critical oncoproteins, has been shown to be heavily associated with the malignant cancer phenotype, including rapid proliferation, metastasis, and chemoresistance across multiple cancer types. The c-Myc proto-oncogene is amplified in small cell lung cancers (SCLCs) and overexpressed in over 50% of NSCLCs. c-Myc is known to actively regulate the transcription of cancer stemness genes that are recognized as major contributors to tumor progression and therapeutic resistance; thus, targeting c-Myc either directly or indirectly in mitigation of the cancer stemness phenotype becomes a promising approach for development of a new strategy against drug resistant lung cancers. This review will summarize what is currently known about the mechanisms underlying c-Myc regulation of cancer stemness and its involvement in drug resistance and offer an overview on the current progress and future prospects in therapeutically targeting c-Myc in both SCLC and NSCLC.

SP1-Induced Upregulation of LncRNA AFAP1-AS1 Promotes Tumor Progression in Triple-Negative Breast Cancer by Regulating mTOR Pathway

The long non-coding RNA (lncRNA) actin fiber-associated protein-1 antisense RNA 1 (AFAP1-AS1) exerted oncogenic activity in triple-negative breast cancer (TNBC). We designed this study and conducted it to investigate the upstream regulation mechanism of AFAP1-AS1 in TNBC tumorigenesis. In this work, we proved the localization of AFAP1-AS1 in the cytoplasm. We elucidated the mechanism by which the transcription factor specificity protein 1 (SP1) modulated AFAP1-AS1 in TNBC progression, which has yet to be thoroughly studied. Dual luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay revealed a strong affinity of SP1 toward the promoter regions P3 of AFAP1-AS1, proving the gene expression regulation of AFAP1-AS1 via SP1 in TNBC. Additionally, SP1 could facilitate the tumorigenesis of TNBC cells in vitro and in vivo by regulating the AFAP1-AS1 expression. Furthermore, silenced AFAP1-AS1 suppressed the expression of genes in the mTOR pathway, such as eukaryotic translation initiation factor 4B (EIF4B), mitogen-activated protein kinase-associated protein 1 (MAPKAP1), SEH1-like nucleoporin (SEH1L), serum/glucocorticoid regulated kinase 1 (SGK1), and its target NEDD4-like E3 ubiquitin protein ligase (NEDD4L), and promoted the gene expression of s-phase kinase-associated protein 2 (SKP2). Overall, this study emphasized the oncogenic role of SP1 and AFAP1-AS1 in TNBC and illustrated the AFAP1-AS1 upstream interaction with SP1 and the downstream modulatory of mTOR signaling, thus offering insights into the tumorigenesis mechanism in TNBC.

Biological effects and mechanisms of fisetin in cancer: a promising anti-cancer agent

Fisetin, a natural flavonoid, possesses numerous biological activities that have been extensively studied in various diseases. When it comes to cancer, fisetin exhibits a range of biological effects, such as suppressing cell growth, triggering programmed cell death, reducing the formation of new blood vessels, protecting against oxidative stress, and inhibiting cell migration. Moreover, fisetin has the ability to enhance the effectiveness of chemotherapy. The anticancer properties of fisetin can be attributed to a diverse array of molecules and signaling pathways, including vascular endothelial growth factor (VEGF), mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-κB), PI3K/Akt/mTOR, and Nrf2/HO-1. Consequently, fisetin holds promise as a therapeutic agent for anticancer treatment. In this review, we place emphasis on the biological functions and various molecular targets of fisetin in anticancer therapy.

RNA modifications in cancer

Currently, more than 170 modifications have been identified on RNA. Among these RNA modifications, various methylations account for two-thirds of total cases and exist on almost all RNAs. Roles of RNA modifications in cancer are garnering increasing interest. The research on m6A RNA methylation in cancer is in full swing at present. However, there are still many other popular RNA modifications involved in the regulation of gene expression post-transcriptionally besides m6A RNA methylation. In this review, we focus on several important RNA modifications including m1A, m5C, m7G, 2'-O-Me, Ψ and A-to-I editing in cancer, which will provide a new perspective on tumourigenesis by peeking into the complex regulatory network of epigenetic RNA modifications, transcript processing, and protein translation.

Sequence-to-expression approach to identify etiological non-coding DNA variations in P53 and cMYC-driven diseases

Background and methods

Disease risk prediction based on DNA sequence and transcriptional profile can improve disease screening, prevention, and potential therapeutic approaches by revealing contributing genetic factors and altered regulatory networks. Despite identifying many disease-associated DNA variants through genome-wide association studies, distinguishing deleterious non-coding DNA variations remains poor for most common diseases. We previously reported that non-coding variations disrupting cis-overlapping motifs (CisOMs) of opposing transcription factors significantly affect enhancer activity. We designed in vitro experiments to uncover the significance of the co-occupancy and competitive binding and inhibition between P53 and cMYC on common target gene expression.

Results

Analyzing publicly available ChIP-seq data for P53 and cMYC in human embryonic stem cells and mouse embryonic cells showed that ~ 344-366 genomic regions are co-occupied by P53 and cMYC. We identified, on average, two CisOMs per region, suggesting that co-occupancy is evolutionarily conserved in vertebrates. Our data showed that treating U2OS cells with doxorubicin increased P53 protein level while reducing cMYC level. In contrast, no change in protein levels was observed in Raji cells. ChIP-seq analysis illustrated that 16-922 genomic regions were co-occupied by P53 and cMYC before and after treatment, and substitutions of cMYC signals by P53 were detected after doxorubicin treatment in U2OS. Around 187 expressed genes near co-occupied regions were altered at mRNA level according to RNA-seq data. We utilized a computational motif-matching approach to determine that changes in predicted P53 binding affinity by DNA variations in CisOMs of co-occupied elements significantly correlate with alterations in reporter gene expression. We performed a similar analysis using SNPs mapped in CisOMs for P53 and cMYC from ChIP-seq data in U2OS and Raji, and expression of target genes from the GTEx portal.

Conclusions

We found a significant correlation between change in motif-predicted cMYC binding affinity by SNPs in CisOMs and altered gene expression. Our study brings us closer to developing a generally applicable approach to filter etiological non-coding variations associated with P53 and cMYC-dependent diseases.

LINC00978 regulates metabolic rewiring to promote the malignancy of glioblastoma through AKR1B1

Glioma is a fatal primary brain tumor. Improved glioma treatment effectiveness depends on a better understanding of its underlying mechanisms. Herein, we reported LINC00978 overexpressed in gliomas. Downregulation of LINC00978 in glioblastoma cells inhibited cell proliferation, invasion, migration, and induced apoptosis. In vivo experiments confirmed that the CamK-A siRNA of LINC00978 could effectively inhibit the proliferation of glioma cells. The main pathway and genes regulated by LINC00978 were detected using RNA sequencing to elucidate the molecular mechanism. The results suggest that LINC00978 regulates the expression of genes related to metabolic pathways, including aldo-keto reductase family 1 member B (AKR1B1), which mediates the cytotoxicity of 2-deoxyglucose. LINC00978 positively regulated AKR1B1 expression, and 2-deoxyglucose induced AKR1B1 expression via a LINC00978-dependent mechanism. This research has revealed that LINC00978 promotes the sensitivity of glioma cells to 2DG. LINC00978 is highly expressed in most glioma patients. Thus, understanding the anticancer mechanism identified in this study may contribute to treating the majority of glioma patients. This study clarified the function and molecular mechanism of LINC00978 in glioblastoma and provided a study basis for LINC00978 to guide the clinical treatment of glioblastoma.

DNA polymerase POLD1 promotes proliferation and metastasis of bladder cancer by stabilizing MYC

To date, most studies on the DNA polymerase, POLD1, have focused on the effect of POLD1 inactivation mutations in tumors. However, the implications of high POLD1 expression in tumorigenesis remains elusive. Here, we determine that POLD1 has a pro-carcinogenic role in bladder cancer (BLCA) and is associated to the malignancy and prognosis of BLCA. Our studies demonstrate that POLD1 promotes the proliferation and metastasis of BLCA via MYC. Mechanistically, POLD1 stabilizes MYC in a manner independent of its' DNA polymerase activity. Instead, POLD1 attenuates FBXW7-mediated ubiquitination degradation of MYC by directly binding to the MYC homology box 1 domain competitively with FBXW7. Moreover, we find that POLD1 forms a complex with MYC to promote the transcriptional activity of MYC. In turn, MYC increases expression of POLD1, forming a POLD1-MYC positive feedback loop to enhance the pro-carcinogenic effect of POLD1-MYC on BLCA. Overall, our study identifies POLD1 as a promotor of BCLA via a MYC driven mechanism and suggest its potential as biomarker for BLCA.

Prognostic Value and Genome Signature of m6A/m5C Regulated Genes in Early-Stage Lung Adenocarcinoma

RNA modifications implicate pathological and prognosis significance in cancer development and progression, of which, m6A and m5C are representative regulators. These RNA modifications could produce effects on the function of other RNA by regulating gene expression. Thus, in this study, we aimed to explore the correlation between m6A/m5C regulators and early-stage lung adenocarcinoma (LUAD). Only the early-stage LUAD samples were included in this investigation, and the RNA-seq dataset of The Cancer Genome Atlas (TCGA) cohort was utilized to evaluate the expression of 37 m6A/m5C regulated genes. Based on the expression level of these 37 genes, early-stage LUAD patients were divided into 2 clusters, which were performed by consensus clustering, and the m6A/m5C subtypes had significantly different prognostic outcomes (p < 0.001). Cluster1, which has a better prognosis, was characterized by the C3 (inflammatory) immune subtype, low immune infiltration, chemokine expression, major histocompatibility complex (MHC) expression, and immune checkpoint molecule expression. Furthermore, compared with cluster1, cluster2 showed a T cell exhaustion state, characterized by a high expression of immune checkpoint genes, and immune cells, such as T cells, CD8+ T cells, cytotoxic lymphocytes, NK cells, and so on. In addition, patients in cluster2 were with high tumor mutational burden (TMB) and numerous significant mutated oncogene and tumor suppressor genes, such as WNT10B, ERBB4, SMARCA4, TP53, and CDKN2A (p < 0.001). A total of 19 genes were mostly related to the prognosis of LUAD and were upregulated in cluster2 (p < 0.05), showing a positive correlation with the mRNA expression of 37 m6A/m5C regulated genes. The predictive risk model was constructed using Cox and LASSO (least absolute shrinkage and selection operator) regression analysis. Finally, a seven-gene m6A/m5C risk model, comprising of METTL3, NPLOC4, RBM15, YTHDF1, IGF2BP1, NSUN3, and NSUN7, was constructed to stratify the prognosis of early-stage LUAD (p = 0.0049, AUC = 0.791). The high-risk score was associated with a poorer prognosis. This model was also validated using two additional GEO datasets: GSE72094 (p = 0.011, AUC = 0.736) and GSE50081 (p = 0.012, AUC = 0.628). In summary, it was established that the m6A/m5C-regulated genes performed a crosstalk function in the mRNA expression of early-stage LUAD. By interacting with other mRNA genes, m6A/m5C modification disturbs DNA replication and the tumor immune microenvironment (TIME). The seven-gene risk model may be a critical tool for the prognostic assessment of early-stage LUAD.

Keratin19 promotes pancreatic cancer progression and poor prognosis via activating the Hedgehog pathway

Pancreatic cancer is a serious threat to human health, with strong invasiveness, rapid progression and poor prognosis. Tumors expressing keratin 19 (K19) have stronger invasiveness and a worse prognosis. However, the role and mechanism of K19 in pancreatic cancer have remained largely elusive. In the present study, K19 expression was detected in pancreatic cancer tissues, its effect on proliferation, apoptosis and metastasis of pancreatic cancer at the cellular, in vivo preclinical and clinical levels was evaluated and its effect on the Hedgehog pathway was analyzed. K19 was significantly overexpressed in pancreatic cancer, promoted pancreatic cancer proliferation and metastasis, inhibited tumor cell apoptosis and was associated with poor prognosis. Mechanistically, these effects were mediated through the activation of the Hedgehog pathway. In conclusion, K19 may be a novel target molecule for pancreatic cancer treatment.

Suppression of Cancer Cell Stemness and Drug Resistance via MYC Destabilization by Deubiquitinase USP45 Inhibition with a Natural Small Molecule

Cancer stem cells (CSCs) play significant roles in cancer development, drug resistance and cancer recurrence. In cancer treatments based on the CSC characteristics and inducing factors, MYC is a promising target for therapeutic molecules. Although it has been regarded as an undrugable target, its stability tightly regulated by the ubiquitin-proteasome system offers a new direction for molecule targeting and cancer treatment. Herein we report our discoveries in this research area, and we have found that deubiquitinase USP45 can directly bind with MYC, resulting in its deubiquitination and stabilization. Further, USP45 overexpressing can upregulate MYC, and this overexpressing can significantly enhance cancer development, cancer cell stemness and drug resistance. Interestingly, without enhancing cancer development, MYC silencing with shRNA can only suppress USP45-induced stemness and drug resistance. Moreover, we have identified that USP45 can be specifically bound and inhibited by a natural small molecule (α-mangostin), in turn significantly suppressing USP45-induced stemness and drug resistance. Since USP45 is significantly expressed in cervical tumors, we have discovered that the combination of α-mangostin and doxorubicin can significantly inhibit USP45-induced cervical tumorigenesis in an animal model. In general, on the basis of our USP45 discoveries on its MYC deubiquitination and α-mangostin inhibition, suppressing USP45 has opened a new window for suppressing cancer development, stemness and drug resistance.

MiR-138-5p suppresses the progression of lung cancer by targeting SNIP1

BACKGROUND

MicroRNAs (miRNAs) play crucial roles in the development of various cancers. Here, we aimed to evaluate the roles of miR-138-5p in lung cancer progression and the value of miR-138-5p in lung cancer diagnosis.

METHODS

Quantitative real-time PCR was performed to examine the expressions of miR-138-5p and smad nuclear interacting protein 1 (SNIP1) mRNA. The diagnostic value of miR-138-5p was analyzed using receiver operating characteristic (ROC) curve analysis, sensitivity, and specificity. We explored the effect of miR-138-5p on cell proliferation and metastasis by CCK-8, colony formation, wound healing and transwell assays. Western blot was employed to detect the protein expression of SNIP1 and related genes. Lung cancer cell growth was evaluated in vivo using xenograft tumor assay.

RESULTS

MiR-138-5p was decreased in the serum of patients with non-small cell lung cancer (NSCLC) and in NSCLC cells and tissues. The area under the ROC curve of serum miR-138-5p in the diagnosis of NSCLC was 0.922. This finding indicates the high diagnostic efficiency for lung cancer. MiR-138-5p suppressed but its inhibitor promoted cell proliferation and migration compared with control treatment in vitro and in vivo. MiR-138-5p directly binds to the 3'-untranslated region of SNIP1 and negatively regulated the expression of SNIP1, thereby inhibiting the expression of cyclin D1 and c-Myc. Moreover, overexpression of SNIP1 rescues the miR-138-5p-mediated inhibition in NSCLC cells.

CONCLUSIONS

The results suggested that miR-138-5p suppressed lung cancer cell proliferation and migration by targeting SNIP1. Serum miR-138-5p is a novel and valuable biomarker for NSCLC diagnosis.

Long Noncoding RNAs and Circular RNAs Regulate AKT and Its Effectors to Control Cell Functions of Cancer Cells

AKT serine-threonine kinase (AKT) and its effectors are essential for maintaining cell proliferation, apoptosis, autophagy, endoplasmic reticulum (ER) stress, mitochondrial morphogenesis (fission/fusion), ferroptosis, necroptosis, DNA damage response (damage and repair), senescence, and migration of cancer cells. Several lncRNAs and circRNAs also regulate the expression of these functions by numerous pathways. However, the impact on cell functions by lncRNAs and circRNAs regulating AKT and its effectors is poorly understood. This review provides comprehensive information about the relationship of lncRNAs and circRNAs with AKT on the cell functions of cancer cells. the roles of several lncRNAs and circRNAs acting on AKT effectors, such as FOXO, mTORC1/2, S6K1/2, 4EBP1, SREBP, and HIF are explored. To further validate the relationship between AKT, AKT effectors, lncRNAs, and circRNAs, more predicted AKT- and AKT effector-targeting lncRNAs and circRNAs were retrieved from the LncTarD and circBase databases. Consistently, using an in-depth literature survey, these AKT- and AKT effector-targeting database lncRNAs and circRNAs were related to cell functions. Therefore, some lncRNAs and circRNAs can regulate several cell functions through modulating AKT and AKT effectors. This review provides insights into a comprehensive network of AKT and AKT effectors connecting to lncRNAs and circRNAs in the regulation of cancer cell functions.

Activation of CD44 signaling in leader cells induced by tumor-associated macrophages drives collective detachment in luminal breast carcinomas

Collective detachment of cancer cells at the invading front could generate efficient metastatic spread. However, how cancer cell clusters shed from the leading front remains unknown. We previously reported that the dynamic expression of CD44 in breast cancers (BrCas) at collectively invading edges was associated with tumor-associated macrophages (TAMs). In this study, we first observed that the highly expressed CD44 (CD44^high) cancer cell clusters were located in the BrCa circulating vessels, accompanied by CD206⁺ TAMs. Next, we identified that the cancer cell clusters can be converted to an invasive CD44^high state which was induced by TAMs, thus giving rise to CD44-associated signaling mediated cohesive detachment. Then, we showed that disrupting CD44-signaling inhibited the TAMs triggered cohesive detaching using 3D organotypic culture and mouse models. Furthermore, our mechanistic study showed that the acquisition of CD44^high state was mediated by the MDM2/p53 pathway activation which was induced by CCL8 released from TAMs. Blocking of CCL8 could inhibit the signaling cascade which decreased the CD44-mediated cohesive detachment and spread. Our findings uncover a novel mechanism underlying collective metastasis in BrCas that may be helpful to seek for potential targets.

Long non-coding RNAs are involved in alternative splicing and promote cancer progression

Alternative splicing (AS) is a key process in which precursor RNAs produce different mature RNAs, and the disorder of AS is a key factor in promoting cancer development. Compared with coding RNA, studies on the functions of long non-coding RNAs (lncRNAs) are far from enough. In fact, lncRNA is an important participant and regulator in the process of AS. On the one hand, lncRNAs regulate cancer progression as AS products of precursor messenger RNA (mRNA), but on the other hand, precursor lncRNA generates cancer-related abnormal splicing variants through AS. In addition, lncRNAs directly or indirectly regulate the AS events of downstream target genes, thus affecting the occurrence and development of cancer. Here, we reviewed how lncRNAs regulate AS and influence oncogenesis in different ways.

LncRNA MNX1-AS1: A novel oncogenic propellant in cancers

To date, recent studies have shown that long non-coding RNAs (lncRNAs) are key players in gene regulation processes involved in cancer pathogenesis. In general, Motor neuron and pancreas homeobox 1-antisense RNA1 (MNX1-AS1) is highly expressed in all cancers as reported so far and exerts oncogenic effects through different mechanisms. In this review, we comprehensively summarize the detailed mechanisms of potential functions of MNX1-AS1 in different cancer types as well as the latest knowledge highlighting the potential of MNX1-AS1 as a therapeutic target for cancer. Aberrant expression of MNX1-AS1 closely correlates with clinicopathological parameters. such as lymphatic metastasis, tumor size, tumor stage, OS and DFS. Thus, MNX1-AS1 can be used as a diagnostic and prognostic biomarker or even a therapeutic prognostic target. This article reviews its function, molecular mechanism and clinical prognosis in various malignancies.

The emerging roles of the interaction between m6A modification and c-Myc in driving tumorigenesis and development

N6-methyladenosine (m6A) is an extremely common and conservative posttranscriptional modification, that can specifically target and regulate the expression or stability of a series of tumor-related genes, thus playing critical roles in the occurrence and development of tumors. c-Myc is an important tumorigenic transcription factor that promotes tumorigenesis and development by mainly regulating the expression of downstream target genes. Increasing evidence shows that m6A modification, as well as abnormal expression and regulation of c-Myc, is critical molecular mechanisms driving tumorigenesis and development. Although more evidence has been uncovered about the individual roles of m6A modification or c-Myc in tumors, the interaction between m6A modification and c-Myc in tumorigenesis and development has not been systematically summarized. Therefore, this review is focused on the mutual regulation between m6A modification and c-Myc expression and stability as well as its roles in tumorigenesis and development. We also summarized the potential value of the interaction between m6A modification and m6A expression and stability in tumor diagnosis and treatment, which provides a specific reference for revealing the mechanism of tumor occurrence and development as well as clinical diagnosis and treatment.

A Signature of 14 Long Non-Coding RNAs (lncRNAs) as a Step towards Precision Diagnosis for NSCLC

LncRNAs have arisen as new players in the world of non-coding RNA. Disrupted expression of these molecules can be tightly linked to the onset, promotion and progression of cancer. The present study estimated the usefulness of 14 lncRNAs (HAGLR, ADAMTS9-AS2, LINC00261, MCM3AP-AS1, TP53TG1, C14orf132, LINC00968, LINC00312, TP73-AS1, LOC344887, LINC00673, SOX2-OT, AFAP1-AS1, LOC730101) for early detection of non-small-cell lung cancer (NSCLC). The total RNA was isolated from paired fresh-frozen cancerous and noncancerous lung tissue from 92 NSCLC patients diagnosed with either adenocarcinoma (LUAD) or lung squamous cell carcinoma (LUSC). The expression level of lncRNAs was evaluated by a quantitative real-time PCR (qPCR). Based on Ct and delta Ct values, logistic regression and gradient boosting decision tree classifiers were built. The latter is a novel, advanced machine learning algorithm with great potential in medical science. The established predictive models showed that a set of 14 lncRNAs accurately discriminates cancerous from noncancerous lung tissues (AUC value of 0.98 ± 0.01) and NSCLC subtypes (AUC value of 0.84 ± 0.09), although the expression of a few molecules was statistically insignificant (SOX2-OT, AFAP1-AS1 and LOC730101 for tumor vs. normal tissue; and TP53TG1, C14orf132, LINC00968 and LOC730101 for LUAD vs. LUSC). However for subtypes discrimination, the simplified logistic regression model based on the four variables (delta Ct AFAP1-AS1, Ct SOX2-OT, Ct LINC00261, and delta Ct LINC00673) had even stronger diagnostic potential than the original one (AUC value of 0.88 ± 0.07). Our results demonstrate that the 14 lncRNA signature can be an auxiliary tool to endorse and complement the histological diagnosis of non-small-cell lung cancer.

Ribosome 18S m6A methyltransferase METTL5 promotes pancreatic cancer progression by modulating c‑Myc translation

Methyltransferase N6‑adenosine (METTL5) is a methyltransferase that specifically catalyzes 18S rRNA N6 methylation at adenosine 1832 (m⁶A₁₈₃₂), which is located in a critical position in the decoding center, therefore suggesting its potential importance in the regulation of translation. However, the underlying mechanism of METTL5‑mediated translation regulation of specific genes and its biological functions are largely undefined. To the best of our knowledge, the present study demonstrated for the first time that METTL5 was an oncogene that promoted cell proliferation, migration, invasion and tumorigenesis in pancreatic cancer. In addition, the oncogenic function of METTL5 may involve an increase in c‑Myc translation, as evidenced by the fact that the oncogenic effect caused by METTL5 overexpression could be abolished by c‑Myc knockdown. Notably, m⁶A modifications at the 5' untranslated region (5'UTR) and coding DNA sequence region (near the 5'UTR) of c‑Myc mRNA played a critical role in the specific translation regulation by METTL5. In addition, it was further demonstrated that METTL5 and its cofactor tRNA methyltransferase activator subunit 11‑2 synergistically promote pancreatic cancer progression. These findings revealed important roles for METTL5 in the development of pancreatic cancer and present the METTL5/c‑Myc axis as a novel therapeutic strategy for treatment.

A Review on the Role of AFAP1-AS1 in the Pathoetiology of Cancer

AFAP1-AS1 is a long non-coding RNA which partakes in the pathoetiology of several cancers. The sense protein coding gene from this locus partakes in the regulation of cytophagy, cell motility, invasive characteristics of cells and metastatic ability. In addition to acting in concert with AFAP1, AFAP1-AS1 can sequester a number of cancer-related miRNAs, thus affecting activity of signaling pathways involved in cancer progression. Most of animal studies have confirmed that AFAP1-AS1 silencing can reduce tumor volume and invasive behavior of tumor cells in the xenograft models. Moreover, statistical analyses in the human subjects have shown strong correlation between expression levels of this lncRNA and clinical outcomes. In the present work, we review the impact of AFAP1-AS1 in the carcinogenesis.