LINC00460-miR-149-5p/miR-150-5p-Mutant p53 Feedback Loop Promotes Oxaliplatin Resistance in Colorectal Cancer

LINC00460 promotes neuroblastoma tumorigenesis and cisplatin resistance by targeting miR-149-5p/DLL1 axis and activating Notch pathway in vitro and in vivo

Long noncoding RNAs (lncRNAs) have been demonstrated to participate in neuroblastoma cisplatin resistance and tumorigenesis. LncRNA LINC00460 was previously reported to play a critical regulatory role in many cancer development. Nevertheless, its role in modulating neuroblastoma cisplatin resistance has not been explored till now. Cisplatin-resistant neuroblastoma cell lines were established by exposing neuroblastoma cell lines to progressively increasing concentrations of cisplatin for 6 months. LINC00460, microRNA (miR)-149-5p, and delta-like ligand 1 (DLL1) mRNA expression was measured through RT-qPCR. The protein levels of DLL1, epithelial-to-mesenchymal transition (EMT) markers, and the Notch signaling-related molecules were measured via western blotting. The IC50 value for cisplatin, cell growth, metastasis and apoptosis were analyzed in cisplatin-resistant neuroblastoma cells. The binding between LINC00460 (or DLL1) and miR-149-5p was validated through dual-luciferase reporter assay. The murine xenograft model was established to perform in vivo assays. LINC00460 and DLL1 levels were elevated, while miR-149-5p level was reduced in cisplatin-resistant neuroblastoma cells. LINC00460 depletion attenuated IC50 values for cisplatin, weakened cell growth, metastasis, and EMT, and enhanced apoptosis in cisplatin-resistant neuroblastoma cells. Mechanically, LINC00460 sponged miR-338-3p to increase DLL1 level, thereby activating Notch signaling pathway. DLL1 overexpression antagonized LINC00460 silencing-induced suppression on neuroblastoma cell cisplatin resistance and malignant behaviors, while such effects were further reversed by treatment with DAPT, the inhibitor of Notch pathway. Additionally, LINC00460 knockdown further augmented cisplatin-induced impairment on tumor growth in vivo. LINC00460 contributes to neuroblastoma cisplatin resistance and tumorigenesis through miR-149-5p/DLL1/Notch pathway, providing new directions to improve the therapeutic efficacy of chemotherapy drugs applied in patients with neuroblastoma.

LncRNA OIP5-AS1 Upregulates the Cyclin D2 Levels to Promote Metastasis of Breast Cancer by Targeting miR-150-5p

OBJECTIVE

Breast cancer (BC) is a cancer that seriously affects women's health. BC cell migration increases the mortality of BC patients. Current studies have shown that long noncoding RNAs (LncRNAs) are related to the metastasis mechanism of BC. This study aimed to explore the function and role of LncRNA OIP5-AS1 in BC. And we analyzed its regulatory mechanism and related modification process.

METHODS

Our study analyzed the expression pattern of OIP5-AS1 in BC tissues and cell lines by qRT-PCR. The effects of OIP5-AS1 on the function of BC cells were detected by CCK-8 and transwell experiments. Bioinformatics analysis and double luciferase reporter gene detection were used to confirm the correlation between OIP5-AS1 and miR-150-5p and between miR-150-5p and Cyclin D2 (CCND2). The rescue test analyzed the effect of miR-150-5p regulating OIP5-AS1. In addition, the N6-methyladenosine (m6A) modification process of OIP5-AS1 was analyzed by RNA m6A dot blot, RIP assay, and double luciferase report experiment.

RESULTS

OIP5-AS1 was significantly upregulated in BC tissues and cell lines. OIP5-AS1 knockdown inhibited BC cell viability, migration and invasion. OIP5-AS1 upregulated CCND2 by binding with miR-150-5p. This process affected the metastasis of BC. Higher degree of m6A methylation was confirmed in BC cell lines. There were some binding sites between methyltransferase like 3 (METTL3) and OIP5-AS1. Moreover, the silencing of METTL3 inhibited the OIP5-AS1 expression through decreasing the m6A methylation levels.

CONCLUSIONS

LncRNA OIP5-AS1 promoted cell viability and metastasis of BC cells by targeting miR-150-5p/CCND2 axis. This process was modified by m6A methylation of METTL3.

Established and emerging biomarkers of immunotherapy in renal cell carcinoma

Immunotherapies, such as immune checkpoint inhibitors, have heralded impressive progress for patient care in renal cell carcinoma (RCC). Despite this success, some patients' disease fails to respond, and other patients experience significant side effects. Thus, development of biomarkers is needed to ensure that patients can be selected to maximize benefit from immunotherapies. Improving clinicians' ability to predict which patients will respond to immunotherapy and which are most at risk of adverse events - namely through clinical biomarkers - is indispensable for patient safety and therapeutic efficacy. Accordingly, an evolving suite of therapeutic biomarkers continues to be investigated. This review discusses biomarkers for immunotherapy in RCC, highlighting current practices and emerging innovations, aiming to contribute to improved outcomes for patients with RCC.

YY1-induced lncRNA00511 promotes melanoma progression via the miR-150-5p/ADAM19 axis

Increasing evidence indicates that long noncoding RNAs (lncRNAs) are therapeutic targets and key regulators of tumors development and progression, including melanoma. Long intergenic non-protein-coding RNA 511 (LINC00511) has been demonstrated as an oncogenic molecule in breast, stomach, colorectal, and lung cancers. However, the precise role and functional mechanisms of LINC00511 in melanoma remain unknown. This study confirmed that LINC00511 was highly expressed in melanoma cells (A375 and SK-Mel-28 cells) and tissues, knockdown of LINC00511 could inhibit melanoma cell migration and invasion, as well as the growth of subcutaneous tumor xenografts in vivo. By using Chromatin immunoprecipitation (ChIP) assay, it was demonstrated that the transcription factor Yin Yang 1 (YY1) is capable of binding to the LINC00511 promoter and enhancing its expression in cis. Further mechanistic investigation showed that LINC00511 was mainly enriched in the cytoplasm of melanoma cells and interacted directly with microRNA-150-5p (miR-150-5p). Consistently, the knockdown of miR-150-5p could recover the effects of LINC00511 knockdown on melanoma cells. Furthermore, ADAM metallopeptidase domain expression 19 (ADAM19) was identified as a downstream target of miR-150-5p, and overexpression of ADAM19 could promote melanoma cell proliferation. Rescue assays indicated that LINC00511 acted as a competing endogenous RNA (ceRNA) to sponge miR-150-5p and increase the expression of ADAM19, thereby activating the PI3K/AKT pathway. In summary, we identified LINC00511 as an oncogenic lncRNA in melanoma and defined the LINC00511/miR-150-5p/ADAM19 axis, which might be considered a potential therapeutic target and novel molecular mechanism the treatment of patients with melanoma.

LINC00460 knockdown sensitizes cervical cancer to cisplatin by downregulating TGFBI

The acquired resistance of cancer to cisplatin (DDP) limits the efficacy of chemotherapy. The prognostic value of long noncoding RNA (lncRNA) LINC00460 has been reported in cervical cancer. However, its effect on DDP sensitivity in cervical cancer remains poorly understood. In present study, LINC00460 was screened out through bioinformatics analysis. The expression levels of mRNAs and proteins were measured by reverse transcription-quantitative PCR (RT-qPCR) or western blot analysis. The sensitivity to DDP was investigated using an CCK8 assay. Cell apoptosis was determined by flow cytometry. The differentially expressed genes that were associated with the poor prognosis of cervical cancer were screened, and their correlations with LINC00460 expression were explored using Pearson's correlation analysis. Tumor xenograft model was used to assess the effect of LINC00460 knockdown on DDP sensitivity in vivo. The interaction between miR-338-3p and LINC00460 or transforming growth factor β-induced protein (TGFBI) was confirmed by RNA immunoprecipitation (RIP) and luciferase reporter assays. LINC00460 expression was increased in cervical cancer tissues and cells. High expression of LINC00460 was associated with dismal prognosis in cervical cancer patients. Silencing of LINC00460 increased drug sensitivity and induced apoptosis in DDP-resistant-cervical cancer cells. LINC00460 knockdown enhanced DDP sensitivity in cervical cancer cells largely by downregulating TGFBI expression. LINC00460 knockdown enhanced the sensitivity of cervical cancer to DDP in vivo, and this effect was partly mediated by the downregulation of TGFBI. LINC00460 positively regulated TGFBI expression, possibly by acting as a sponge of miR-338-3p. LINC00460 knockdown contributed to DDP sensitivity of cervical cancer by downregulating TGFBI, providing a novel mechanism underlying the acquisition of DDP sensitivity.

P53‑microRNA interactions regulate the response of colorectal tumor cells to oxaliplatin under normoxic and hypoxic conditions

Oxaliplatin (OXA)‑containing regimens are used as first‑line chemotherapy in colorectal cancer (CRC). However, OXA resistance remains a major challenge in CRC treatment. CRC cells that adapt to hypoxia can potentially develop OXA resistance, and the underlying molecular mechanisms still need to be further investigated. In the current study, the OXA drug sensitivity of two CRC cell lines, HCT116 (TP53WT) and HT29 (TP53MT), was compared under both normoxic and hypoxic conditions. It was found that under normoxic condition, HCT116 cells showed significantly higher OXA sensitivity than HT29 cells. However, both cell lines showed remarkable OXA resistance under hypoxic conditions. It was also revealed that P53 levels were increased after OXA and hypoxia treatment in HCT116 cells but not in HT29 cells. Notably, knocking down P53WT decreased normoxic but increased hypoxic OXA sensitivity in HCT116 cells, which did not exist in HT29 cells. Molecular analysis indicated that P53WT activated microRNA (miR)‑26a and miR‑34a in OXA treatment and activated miR‑23a in hypoxia treatment. Cell proliferation experiments indicated that a high level of miR‑23a decreased OXA sensitivity and that a high level of miR‑26a or miR‑34a increased OXA sensitivity in HCT116 cells. Additionally, it was demonstrated that miR‑26a, miR‑34a and miR‑23a affect cell apoptosis through regulation of MCL‑1, EZH2, BCL‑2, SMAD 4 and STAT3. Taken together, the present findings revealed the dual function of P53 in regulating cellular chemo‑sensitivity and highlighted the role of P53‑miR interactions in the response of CRC cells to OXA chemotherapy under normoxic and hypoxic conditions.

Identification and verification of a prognostic signature based on a miRNA-mRNA interaction pattern in colon adenocarcinoma

The expression characteristics of non-coding RNA (ncRNA) in colon adenocarcinoma (COAD) are involved in regulating various biological processes. To achieve these functions, ncRNA and a member of the Argonaute protein family form an RNA-induced silencing complex (RISC). The RISC is directed by ncRNA, especially microRNA (miRNA), to bind the target complementary mRNAs and regulate their expression by interfering with mRNA cleavage, degradation, or translation. However, how to identify potential miRNA biomarkers and therapeutic targets remains unclear. Here, we performed differential gene screening based on The Cancer Genome Atlas dataset and annotated meaningful differential genes to enrich related biological processes and regulatory cancer pathways. According to the overlap between the screened differential mRNAs and differential miRNAs, a prognosis model based on a least absolute shrinkage and selection operator-based Cox proportional hazards regression analysis can be established to obtain better prognosis characteristics. To further explore the therapeutic potential of miRNA as a target of mRNA intervention, we conducted an immunohistochemical analysis and evaluated the expression level in the tissue microarray of 100 colorectal cancer patients. The results demonstrated that the expression level of POU4F1, DNASE1L2, and WDR72 in the signature was significantly upregulated in COAD and correlated with poor prognosis. Establishing a prognostic signature based on miRNA target genes will help elucidate the molecular pathogenesis of COAD and provide novel potential targets for RNA therapy.

Intergenic CircRNA Circ_0007379 Inhibits Colorectal Cancer Progression by Modulating miR-320a Biogenesis in a KSRP-Dependent Manner

Circular RNAs (circRNAs) are covalently closed RNA structures that play multiple roles in tumorigenesis and progression. Compared with exon‒intron circRNAs, the biological functions and implications of intergenic circRNAs in human cancer are still poorly understood. Here, we performed circRNA microarray analysis and identified an intergenic circRNA, circ_0007379, that was significantly downregulated in patients with colorectal cancer (CRC). The biogenesis of circ_0007379 was mediated by reverse complementary matches (RCMs) and was negatively regulated by the RNA helicase DHX9. Functionally, circ_0007379 suppressed CRC cell growth and metastasis in cell culture as well as in patient-derived organoid and xenograft models. Mechanistically, circ_0007379 acted as a scaffold to facilitate the processing of both pri-miR-320a and pre-miR-320a in a KSRP-dependent manner, leading to miR-320a maturation and subsequent repression of transcription factor RUNX1 expression. Thus, our findings establish a previously unrecognized function of circRNA in inhibiting CRC progression.

Downregulation of AC092894.1 promotes oxaliplatin resistance in colorectal cancer via the USP3/AR/RASGRP3 axis

BACKGROUND

Oxaliplatin resistance is a complex process and has been one of the most disadvantageous factors and indeed a confrontation in the procedure of colorectal cancer. Recently, long non-coding RNAs (lncRNAs) have emerged as novel molecules for the treatment of chemoresistance, but the specific molecular mechanisms mediated by them are poorly understood.

METHODS

The lncRNAs associated with oxaliplatin resistance were screened by microarray. lncRNA effects on oxaliplatin chemoresistance were then verified by gain- and loss-of-function experiments. Finally, the potential mechanism of AC092894.1 was explored by RNA pull-down, RIP, and Co-IP experiments.

RESULTS

AC092894.1 representation has been demonstrated to be drastically downregulated throughout oxaliplatin-induced drug-resistant CRC cells. In vivo and in vitro experiments revealed that AC092894.1 functions to reverse chemoresistance. Studies on the mechanism suggested that AC092894.1 served as a scaffold molecule that mediated the de-ubiquitination of AR through USP3, thereby increasing the transcription of RASGRP3. Finally, sustained activation of the MAPK signaling pathway induced apoptosis in CRC cells.

CONCLUSIONS

In conclusion, this study identified AC092894.1 as a suppressor of CRC chemoresistance and revealed the idea that targeting the AC092894.1/USP3/AR/RASGRP3 signaling axis is a novel option for the treatment of oxaliplatin resistance.

Metabolism-related long non-coding RNA in the stomach cancer associated with 11 AMMLs predictive nomograms for OS in STAD

Background: The metabolic processes involving amino acids are intimately linked to the onset and progression of cancer. Long non-coding RNAs (LncRNAs) perform an indispensable function in the modulation of metabolic processes as well as the advancement of tumors. Non-etheless, research into the role that amino acid metabolism-related LncRNAs (AMMLs) might play in predicting the prognosis of stomach adenocarcinoma (STAD) has not been done. Therefore, This study sought to design a model for AMMLs to predict STAD-related prognosis and elucidate their immune properties and molecular mechanisms.

Methods: The STAD RNA-seq data in the TCGA-STAD dataset were randomized into the training and validation groups in a 1:1 ratio, and models were constructed and validated respectively. In the molecular signature database, This study screened for genes involved in amino acid metabolism. AMMLs were obtained by Pearson’s correlation analysis, and predictive risk characteristics were established using least absolute shrinkage and selection operator (LASSO) regression, univariate Cox analysis, and multivariate Cox analysis. Subsequently, the immune and molecular profiles of high- and low-risk patients and the benefit of the drug were examined.

Results: Eleven AMMLs (LINC01697, LINC00460, LINC00592, MIR548XHG, LINC02728, RBAKDN, LINCOG, LINC00449, LINC01819, and UBE2R2-AS1) were used to develop a prognostic model. Moreover, high-risk individuals had worse overall survival (OS) than low-risk patients in the validation and comprehensive groups. A high-risk score was associated with cancer metastasis as well as angiogenic pathways and high infiltration of tumor-associated fibroblasts, Treg cells, and M2 macrophages; suppressed immune responses; and a more aggressive phenotype.

Conclusion: This study identified a risk signal associated with 11 AMMLs and established predictive nomograms for OS in STAD. These findings will help us personalize treatment for gastric cancer patients.

Mutual interaction of lncRNAs and epigenetics: focusing on cancer

Long noncoding RNAs are characterized as noncoding transcripts longer than 200 nucleotides in response to a variety of functions within the cells. They are involved in almost all cellular mechanisms so as epigenetics. Given that epigenetics is an important phenomenon, which participates in the biology of complex diseases, many valuable studies have been performed to demonstrate the control status of lncRNAs and epigenetics. DNA methylation and histone modifications as epigenetic mechanisms can regulate the expression of lncRNAs by affecting their coding genes. Reciprocally, the three-dimensional structure of lncRNAs could mechanistically control the activity of epigenetic-related enzymes. Dysregulation in the mutual interaction between epigenetics and lncRNAs is one of the hallmarks of cancer. These mechanisms are either directly or indirectly involved in various cancer properties such as proliferation, apoptosis, invasion, and metastasis. For instance, lncRNA HOTAIR plays a role in regulating the expression of many genes by interacting with epigenetic factors such as DNA methyltransferases and EZH2, and thus plays a role in the initiation and progression of various cancers. Conversely, the expression of this lncRNA is also controlled by epigenetic factors. Therefore, focusing on this reciprocated interaction can apply to cancer management and the identification of prognostic, diagnostic, and druggable targets. In the current review, we discuss the reciprocal relationship between lncRNAs and epigenetic mechanisms to promote or prevent cancer progression and find new potent biomarkers and targets for cancer diagnosis and therapy.

LncRNAs in colorectal cancer: Biomarkers to therapeutic targets

Colorectal cancer (CRC) is the third leading cause of cancer-related death in men and women worldwide. As early detection is associated with lower mortality, novel biomarkers are urgently needed for timely diagnosis and appropriate management of patients to achieve the best therapeutic response. Long noncoding RNAs (lncRNAs) have been reported to play essential roles in CRC progression. Accordingly, the regulatory roles of lncRNAs should be better understood in general and for identifying diagnostic, prognostic and predictive biomarkers in CRC specifically. In this review, the latest advances on the potential diagnostic and prognostic lncRNAs as biomarkers in CRC samples were highlighted, Current knowledge on dysregulated lncRNAs and their potential molecular mechanisms were summarized. The potential therapeutic implications and challenges for future and ongoing research in the field were also discussed. Finally, novel insights on the underlying mechanisms of lncRNAs were examined as to their potential role as biomarkers and therapeutic targets in CRC. This review may be used to design future studies and advanced investigations on lncRNAs as biomarkers for the diagnosis, prognosis and therapy in CRC.

Circular RNA circ-CD44 regulates chemotherapy resistance by targeting the miR-330-5p/ABCC1 axis in colorectal cancer cells

BACKGROUND

Colorectal cancer (CRC) is a common malignant tumor worldwide, ranking fourth for incidence. Recently, circular RNAs (circRNAs) have been demonstrated to play a key role in chemotherapy resistance to CRC treatment. Therefore, the role of circ-CD44 is investigated in CRC.

METHODS

The expression levels of circ-CD44, miR-330-5p, and ATP binding cassette subfamily C member 1 (ABCC1) were quantified by real-time quantitative polymerase chain reaction (RT-qPCR) assay. The sensitivity of CRC cells to oxaliplatin (OXA) was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT) assay. Colony-forming experiment was performed to measure the colony-forming ability of CRC cells. The apoptosis, migration, and invasion of CRC cells were determined by flow cytometry and transwell assays. A xenograft experiment was established to clarify the functional role of circ-CD44 silencing in vivo. The interactional relationship among circ-CD44, miR-330-5p, and ABCC1 was confirmed by dual-luciferase reporter and RNA immunoprecipitation assays. The protein expression of ABCC1 was quantified by western blot assay.

RESULTS

Circ-CD44 was obviously upregulated in OXA-resistant colorectal cancer tissues and cells. Loss-of-function experiments revealed that inhibition of circ-CD44 suppressed proliferation, migration, and invasion while it increased OXA sensitivity and apoptosis in OXA-resistant colorectal cancer cells, which was overturned by suppression of miR-330-5p; besides, silencing of circ-CD44 also slowed the tumor growth in vivo. Additionally, overexpression of miR-330-5p inhibited chemotherapy resistance, proliferation, migration, and invasion while it induced apoptosis by targeting ABCC1.

CONCLUSION

Mechanistically, circ-CD44 functioned as a miRNA sponge for miR-330-5p to upregulate the expression of ABCC1 and regulate chemotherapy resistance in CRC cells.

Emerging roles of non-coding RNAs in colorectal cancer oxaliplatin resistance and liquid biopsy potential

Colorectal cancer (CRC) is one of the most common malignancies of the digestive tract, with the annual incidence and mortality increasing consistently. Oxaliplatin-based chemotherapy is a preferred therapeutic regimen for patients with advanced CRC. However, most patients will inevitably develop resistance to oxaliplatin. Many studies have reported that non-coding RNAs (ncRNAs), such as microRNAs, long non-coding RNAs, and circular RNAs, are extensively involved in cancer progression. Moreover, emerging evidence has revealed that ncRNAs mediate chemoresistance to oxaliplatin by transcriptional and post-transcriptional regulation, and by epigenetic modification. In this review, we summarize the mechanisms by which ncRNAs regulate the initiation and development of CRC chemoresistance to oxaliplatin. Furthermore, we investigate the clinical application of ncRNAs as promising biomarkers for liquid CRC biopsy. This review provides new insights into overcoming oxaliplatin resistance in CRC by targeting ncRNAs.

LINC00460 Facilitates Cell Proliferation and Inhibits Ferroptosis in Breast Cancer Through the miR-320a/MAL2 Axis

Background: Emerging evidence suggests that long noncoding RNAs (lncRNAs) play an important role in the progression of multiple human cancers including breast cancer. In this study, we aimed to research novel functions of long intergenic noncoding RNA 460 (LINC00460) on cell proliferation and ferroptosis in breast cancer. Method: UALCAN, TANRIC, and GSE16446 data were used to analyze the expression of LINC00460 in breast cancer tissues. Furthermore, real-time quantitative PCR, western blot, cell proliferation assay, iron assay, and malondialdehyde (MDA) assay were applied to detect the function and mechanism of particular molecules. Results: The LINC00460 expression was significantly increased in breast cancer tissues compared with normal tissues. Importantly, patients with high LINC00460 expression showed a longer overall survival rate. LINC00460 knockdown markedly suppressed the proliferation of breast cancer cells and promoted ferroptosis. Mechanistic analysis revealed that LINC00460 promoted myelin and lymphocyte protein 2 (MAL2) expression by sponging miR-320a. Moreover, both miR-320a knockdown and MAL2 overexpression could reverse the effects of LINC00460 silencing on cell proliferation and ferroptosis. Conclusions: In summary, our results reveal an alternative mechanism by which breast cancer cells can acquire resistance to ferroptosis via the LINC00460/miR-320a/MAL2 axis.

The Role of Long Noncoding RNA (lncRNAs) Biomarkers in Renal Cell Carcinoma

Renal cell carcinoma is one of the common cancers whose incidence and mortality are continuously growing worldwide. Initially, this type of tumour is usually asymptomatic. Due to the lack of reliable diagnostic markers, one-third of ccRCC patients already have distant metastases at the time of diagnosis. This underlines the importance of establishing biomarkers that would enable the prediction of the disease's course and the risk of metastasis. LncRNA, which modulates genes at the epigenetic, transcriptional, and post-transcriptional levels, appears promising. The actions of lncRNA involve sponging and sequestering target miRNAs, thus affecting numerous biological processes. Studies have confirmed the involvement of RNAs in various diseases, including RCC. In this review, we focused on MALAT1 (a marker of serious pathological changes and a factor in the promotion of tumorigenesis), RCAT1 (tumour promoter in RCC), DUXAP9 (a plausible marker of localized ccRCC), TCL6 (exerting tumour-suppressive effects in renal cancer), LINC00342 (acting as an oncogene), AGAP2 Antisense1 (plausible predictor of RCC progression), DLEU2 (factor promoting tumours growth via the regulation of epithelial-mesenchymal transition), NNT-AS1 (sponge of miR-22 contributing to tumour progression), LINC00460 (favouring ccRCC development and progression) and Lnc-LSG1 (a factor that may stimulate ccRCC metastasis).

LINC00460 Promotes Cutaneous Squamous Cell Carcinoma Progression Through Stabilizing ELAVL1 Protein

Long intergenic noncoding ribonucleic acid (lncRNA) 460 is reportedly associated with carcinogenesis and progression in various types of cancer. However, the mechanisms underlying its action in cutaneous squamous cell carcinoma (CSCC) remain unclear. LINC00460 mRNA expression was analysed using data from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Cell growth, migration, and invasion were evaluated using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), transwell migration and invasion assays after inducing LINC00460 knockdown. A xenograft tumour model was used to determine the effects of LINC00460 on tumour growth and metastasis in vivo. To examine the interaction between LINC00460 and ELAVL1, RNA pulldown and RNA immunoprecipitation assays were performed. LINC00460 was found to be significantly upregulated in CSCC tissues and cell lines. Functionally, LINC00460 knockdown inhibited cell proliferation, migration, and invasion in vitro. Consistent with this, when LINC00460 expression decreased, CSCC tumorigenesis and metastasis in vivo were inhibited. Mechanistically, LINC00460 binds to embryonic lethal abnormal vision like RNA binding protein 1 (ELAVL1) and enhances its stability by inhibiting the β-transducin repeats-containing protein (β-TrCP)-mediated ubiquitination of ELAVL1. Moreover, the effect of LINC00460 silencing on the proliferation, migration, and invasion of CSCC cells could be reversed by overexpressing ELAVL1. Our findings demonstrated that LINC00460 plays a critical role in regulating ELAVL1 function. This highlights the potential targets for the clinical diagnosis and treatment of CSCC.

Tumor-Suppressive and Oncogenic Roles of microRNA-149-5p in Human Cancers

Malignant tumors are always a critical threat to human health, with complex pathogenesis, numerous causative factors, and poor prognosis. The features of cancers, such as gene mutations, epigenetic alterations, and the activation and inhibition of signaling pathways in the organism, play important roles in tumorigenesis and prognosis. MicroRNA (miRNA) enables the control of various molecular mechanisms and plays a variety of roles in human cancers, such as radiation sensitivity and tumor immunity, through the regulation of target genes. MiR-149-5p participates in the process and is closely related to lipogenesis, the migration of vascular endothelial cells, and the expression of stem-cell-related proteins. In recent years, its role in cancer has dramatically increased. In this review, we summarize the regular physiological roles of miRNAs, specifically miR-149-5p, in the organism and discuss the tumor-suppressive or oncogenic roles of miR-149-5p in different human cancers with respect to signaling pathways involved in regulation. Possible clinical applications of miR-149-5p in future targeted therapies and prognosis improvement in oncology are suggested.

Oncogenic roles of the lncRNA LINC00460 in human cancers

Long noncoding RNAs (lncRNAs) represent an important group of endogenous RNAs with limit protein-encoding capability, with a length of more than 200 nucleotides. Emerging evidence have demonstrated that lncRNAs are greatly involved in multiple cancers by playing critical roles in tumor initiation and progression. Long intergenic non-protein coding RNA 460 (LINC00460), a novel cancer-related lncRNA, exhibits abnormal expression and oncogenic function in multiple cancers, and positively correlates with poor clinical characteristics of cancer patients. LINC00460 has also been shown to be a promising biomarker for diagnosis as well as prognostic evaluation in cancer patients. In this review, we briefly summarized recent knowledge on the expression, functional roles, molecular mechanisms, and diagnostic and prognostic values of LINC00460 in human malignancies.

LncRNA PCGEM1 promotes colorectal cancer cell proliferation and migration in positive feedback loop through PCGEM1/miR-433-3p/CTCF axis

BACKGROUND AND OBJECTIVES

Prostate cancer gene expression marker 1 (PCGEM1) has been identified as an oncogenic long non-coding RNA (lncRNA) in diverse cancers, but it has never been linked with colorectal cancer (CRC). Former studies have shown the mutual regulation between lncRNAs and transcription factors (TFs) in cancer. CCCTC binding factor (CTCF) has been reported to transcriptionally activate lncRNAs in cancers. We predicted the binding of CTCF on PCGEM1 promoter through UCSC (https://genome.ucsc.edu/), but their relation has not been studied. We aimed to investigate whether and how PCGEM1 functioned in CRC cells and the interaction between PCGEM1 and CTCF.

METHODS AND RESULTS

The impacts of PCGEM1 and CTCF inhibition on CRC cells were verified through loss-of-function experiments. Mechanism experiments were used to prove the binding between CTCF and PCGEM1 in CRC progression. PCGEM1 possessed a high expression level in CRC cells as well as tumors. CTCF transcriptionally activated PCGEM1 expression. Knockdown of PCGEM1 or CTCF impeded proliferation and migration and drove apoptosis of CRC cells. Moreover, PCGEM1 bound miR-433-3p to prevent miR-433-3p from targeting CTCF.

CONCLUSION

We first revealed PCGEM1/miR-433-3p/CTCF positive feedback loop as an oncogenic axis in CRC cells, which potentially provides new clues for the advancement of CRC treatment.

LncRNA ALDB-898 modulates intestinal epithelial cell damage caused by Clostridium perfringens type C in piglet by regulating ssc-miR-122-5p/OCLN signaling

Diarrhea of piglets caused by Clostridium perfringens type C (C. perfringens type C) infection is a global problem afflicting piglet production. Long noncoding RNA (LncRNA) and microRNA (miRNA) have emerged as critical regulators of this pathological process, but the underlying molecular mechanisms remain unclear. In this study, we first observed the expression changes of ALDBSSCG0000000898 (ALDB-898) and ssc-miR-122-5p in infected ileum tissue of piglets with C. perfringens type C, and then used C. perfringens beta2 toxin (CPB2) to induce intestinal porcine epithelial cells (IPEC-J2) to construct an injury model. Cytometry kit 8 (CCK-8), lactate dehydrogenase (LDH), real-time quantitative polymerase chain reaction (RT-qPCR), Western blot, flow cytometry and fluorescein isothiocyanate-dextran 4 (FITC-Dextran 4) flux assays were performed to study the effect of ALDB-898 and ssc-miR-122-5p in apoptosis, inflammation and intestinal barrier damage and inflammatory in IPEC-J2 cells induced by CPB2. In addition, dual-luciferase reporter gene analysis was performed to confirm the relationship between ssc-miR-122-5p and ALDB-898 or ssc-miR-122-5p and occludin (OCLN), respectively. There were lower expression levels of ALDB-898 and OCLN and higher expression levels of ssc-miR-122-5p in diarrhea piglets caused by Clostridium perfringens type C. ALDB-898 and OCLN were significantly decreased and ssc-miR-122-5p was increased in IPEC-J2 after exposure to the CPB2 in a dose- and time-dependent manner. ALDB-898 overexpression mitigated CPB2-induced cell injury by promoting viability, restraining apoptosis, cytotoxicity, and inflammatory response, as well as weakening the destruction of the intestinal barrier. Further mechanisms disclosed that ALDB-898 functioned as a competing endogenous RNA (ceRNA) via binding to ssc-miR-122-5p, and OCLN was a target of ssc-miR-122-5p. Importantly, the ssc-miR-122-5p mimic led to abolishing the protective function of ALDB-898 on CPB2-induced IPEC-J2 cell damage, and the addition of OCLN reversed the negative impact of ssc-miR-122-5p, thereby restoring the protection of ALDB-898. Our data showed that ALDB-898 could enhance the expression of OCLN through competitive binding ssc-miR-122-5p to suppress CPB2-induced damage. The ALDB-898/ssc-miR-122-5p/OCLN signaling may be a candidate therapeutic pathway for diarrhea of piglets.

P63 and P73 Activation in Cancers with p53 Mutation

The members of the p53 family comprise p53, p63, and p73, and full-length isoforms of the p53 family have a tumor suppressor function. However, p53, but not p63 or p73, has a high mutation rate in cancers causing it to lose its tumor suppressor function. The top and second-most prevalent p53 mutations are missense and nonsense mutations, respectively. In this review, we discuss possible drug therapies for nonsense mutation and a missense mutation in p53. p63 and p73 activators may be able to replace mutant p53 and act as anti-cancer drugs. Herein, these p63 and p73 activators are summarized and how to improve these activator responses, particularly focusing on p53 gain-of-function mutants, is discussed.

miR-150-5p inhibits nasopharyngeal cancer genesis by suppressing PYCR1

BACKGROUND

Nasopharyngeal cancer (NPC) is a rare cancer type with a low five-year survival rate. Dysregulation of PYCR1 and miR-150-5p has been involved in the development of various cancers. However, the molecular mechanism of the miR-150-5p-PYCR1 axis in NPC remains unclear.

METHODS

The expressions of miR-150-5p and PYCR1 in NPC tissues and cells were measured by RT-qPCR. The luciferase assay and RNA pull-down assay were used to confirm the interaction between miR-150-5p and PYCR1. The function of overexpression of miR-150-5p and PYCR1 were detected by cell viability, proliferation, migration and invasion in NPC C666-1 and SUNE-1 cells.

RESULTS

The miR-150-5p expression was reduced in NPC tissues and cells and negatively correlated with PYCR1 level. Upregulation of miR-150-5p conspicuously repressed cell growth. However, upregulation of PYCR1 significantly facilitated the development of NPC, which further suppressed NPC tumorigenesis by abolishing the effect of miR-150-5p.

CONCLUSIONS

We clarified that miR-150-5p attenuated NPC tumorigenesis through reducing PYCR1 expression. This provides a new perspective of NPC involving both miR-150-5p and PYCR1 for the treatment of NPC.

YTHDF3 Facilitates eIF2AK2 and eIF3A Recruitment on mRNAs to Regulate Translational Processes in Oxaliplatin-Resistant Colorectal Cancer

Oxaliplatin, as a first-line drug, frequently causes chemo-resistance in colorectal cancer (CRC). The role of N6-methyladenosine (m6A) modification in multiple biological functions has been well studied. However, the molecular mechanisms underlying m6A methylation in modulating anti-cancer drug resistance in CRC remain obscure. In the present study, we found that YTH m6A RNA-binding protein 3 (YTHDF3) was highly expressed in oxaliplatin-resistant (OXAR) CRC tissues and cells. Moreover, we observed that YTHDF3 could recognize the 5' untranslated region of significantly m6A-methylated RNAs, which were associated with tumor resistance and recruit eukaryotic translation initiation factor 3 subunit A (eIF3A) to facilitate the translation of these target genes. Furthermore, we determined that eukaryotic translation initiation factor 2 alpha kinase 2 (eIF2AK2) bridged YTHDF3 and eIF3A, enhancing the stability of the YTHDF3/eIF3A complex in OXAR CRC cells. Taken together, our data identified YTHDF3 as a novel hallmark and revealed the molecular mechanism of YTHDF3 on gene translation via coordination with eIF2AK2 in OXAR CRC cells.

LncRNAs driving feedback loops to boost drug resistance: sinuous pathways in cancer

Feedback loops mediate signaling pathways to maintain cellular homeostasis. There are two types, positive and negative feedback loops. Both are subject to alterations, and consequently can become pathogenic in the development of diseases such as cancer. Long noncoding RNAs (lncRNAs) are regulators of signaling pathways through feedback loops hidden as the dark regulatory elements yet to be described with great impact on cancer tumorigenesis, development, and drug resistance. Several feedback loops have been studied in cancer, however, how they are regulated by lncRNAs is hardly evident, setting a trending topic in oncological research. In this review, we recapitulate and discuss the feedback loops that are regulated by lncRNAs to promote drug resistance. Furthermore, we propose additional strategies that allow us to identify, analyze and comprehend feedback loops regulated by lncRNAs to induce drug resistance or even to gain insight into novel feedback loops that are stimulated under the pressure of treatment and consequently increase its efficacy. This knowledge will be useful to optimize the therapeutic use of oncological drugs.

A Review on the Role of miR-149-5p in the Carcinogenesis

miR-149 is an miRNA with essential roles in carcinogenesis. This miRNA is encoded by the MIR149 gene on 2q37.3. The miR-149 hairpin produces miR-149-5p and miR-149-3p, which are the “guide” and the sister “passenger” strands, respectively. Deep sequencing experiments have shown higher prevalence of miR-149-5p compared with miR-149-3p. Notably, both oncogenic and tumor suppressive roles have been reported for miR-149-5p. In this review, we summarize the impact of miR-149-5p in the tumorigenesis and elaborate mechanisms of its involvement in this process in a variety of neoplastic conditions based on three lines of evidence, i.e., in vitro, in vivo and clinical settings.

The Relationship Between the Network of Non-coding RNAs-Molecular Targets and N6-Methyladenosine Modification in Colorectal Cancer

Recent accumulating researches implicate that non-coding RNAs (ncRNAs) including microRNA (miRNA), circular RNA (circRNA), and long non-coding RNA (lncRNAs) play crucial roles in colorectal cancer (CRC) initiation and development. Notably, N6-methyladenosine (m⁶A) methylation, the critical posttranscriptional modulators, exerts various functions in ncRNA metabolism such as stability and degradation. However, the interaction regulation network among ncRNAs and the interplay with m⁶A-related regulators has not been well documented, particularly in CRC. Here, we summarize the interaction networks and sub-networks of ncRNAs in CRC based on a data-driven approach from the publications (IF > 6) in the last quinquennium (2016–2021). Further, we extend the regulatory pattern between the core m⁶A regulators and m⁶A-related ncRNAs in the context of CRC metastasis and progression. Thus, our review will highlight the clinical potential of ncRNAs and m⁶A modifiers as promising biomarkers and therapeutic targets for improving the diagnostic precision and treatment of CRC.

Knockdown of circular RNA septin 9 inhibits the malignant progression of breast cancer by reducing the expression of solute carrier family 1 member 5 in a microRNA-149-5p-dependent manner

Breast cancer (BC) is the most frequently diagnosed cancer in women. Increasing evidence suggests that circular RNA (circRNA) exerts critical functions in BC progression. However, the roles of circRNA septin 9 (circSEPT9) in BC development and the underneath mechanism remain largely unclear so far. In this work, the RNA levels of circSEPT9, microRNA-149-5p (miR-149-5p) and solute carrier family 1 member 5 (SLC1A5) were detected by quantitative real-time polymerase chain reaction. Western blot was performed to check protein expression. Glutamine uptake, cell proliferation and cell apoptosis were investigated by glutamine uptake, cell counting kit-8, cell colony formation, 5-Ethynyl-29-deoxyuridine, flow cytometry analysis or DNA content quantitation assay. The interactions of miR-149-5p with circSEPT9 and SLC1A5 were identified by a dual-luciferase reporter assay. Mouse model assay was carried out to analyze the effect of circSEPT9 on tumor formation in vivo. Results showed that circSEPT9 and SLC1A5 expression were significantly upregulated, while miR-149-5p was downregulated in BC tissues and cells as compared with paracancerous normal breast tissues and human normal breast cells. Knockdown of circSEPT9 or SLC1A5 inhibited glutamine uptake and cell proliferation, but induced cell apoptosis in BC cells. SLC1A5 overexpression relieved circSEPT9 silencing-induced repression of BC cell malignancy. In mechanism, circSEPT9 regulated SLC1A5 expression by sponging miR-149-5p. In support, circSEPT9 knockdown led to delayed tumor tumorigenesis in vivo. In summary, these results indicates that circSEPT9 may act an oncogenic role in BC malignant progression by regulating miR-149-5p/SLC1A5 pathway, providing a novel mechanism responsible for BC development.

MicroRNA hsa-miR-150-5p inhibits nasopharyngeal carcinogenesis by suppressing PYCR1 (pyrroline-5-carboxylate reductase 1)

Nasopharyngeal cancer is a rare cancer type, but with a low five-year survival rate. Dysregulation of pyrroline-5-carboxylate reductase 1 (PYCR1) and microRNA hsa-miR-150-5p is involved in the development of various cancers. However, the molecular mechanism of the hsa-miR-150-5p-PYCR1 axis in nasopharyngeal cancer remains unclear. To identify the mechanism of the hsa-miR-150-5p-PYCR1 axis, the expression of hsa-miR-150-5p and PYCR1 in nasopharyngeal cancer tissues and cells was first measured by reverse transcription quantitative polymerase chain reaction. The luciferase and RNA pull-down assays were used to confirm the interaction between hsa-miR-150-5p and PYCR1. The overexpression of hsa-miR-150-5p and PYCR1 was detected by cell viability, proliferation, western blotting, migration, and invasion in nasopharyngeal cancer cells. The expression levels of hsa-miR-150-5p was reduced in the nasopharyngeal cancer tissues and cells and were negatively correlated with the PYCR1 levels. The upregulation of hsa-miR-150-5p significantly repressed cell growth and promoted apoptosis. However, the upregulation of PYCR1 expression significantly promoted nasopharyngeal carcinogenesis, which could abolish the inhibitory effect of hsa-miR-150-5p. In conclusion, we clarified that hsa-miR-150-5p attenuated nasopharyngeal carcinogenesis by reducing the PYCR1 expression levels. This provides a new perspective of nasopharyngeal cancer involving both hsa-miR-150-5p and PYCR1 for the treatment of nasopharyngeal cancer.

Tumor Suppressor miRNA in Cancer Cells and the Tumor Microenvironment: Mechanism of Deregulation and Clinical Implications

MicroRNAs (miRNAs) are noncoding RNAs that have been identified as important posttranscriptional regulators of gene expression. miRNAs production is controlled at multiple levels, including transcriptional and posttranscriptional regulation. Extensive profiling studies have shown that the regulation of mature miRNAs expression plays a causal role in cancer development and progression. miRNAs have been identified to act as tumor suppressors (TS) or as oncogenes based on their modulating effect on the expression of their target genes. Upregulation of oncogenic miRNAs blocks TS genes and leads to tumor formation. In contrast, downregulation of miRNAs with TS function increases the translation of oncogenes. Several miRNAs exhibiting TS properties have been studied. In this review we focus on recent studies on the role of TS miRNAs in cancer cells and the tumor microenvironment (TME). Furthermore, we discuss how TS miRNA impacts the aggressiveness of cancer cells, with focus of the mechanism that regulate its expression. The study of the mechanisms of miRNA regulation in cancer cells and the TME may paved the way to understand its critical role in the development and progression of cancer and is likely to have important clinical implications in a near future. Finally, the potential roles of miRNAs as specific biomarkers for the diagnosis and the prognosis of cancer and the replacement of tumor suppressive miRNAs using miRNA mimics could be promising approaches for cancer therapy.

MiR-149-5p: An Important miRNA Regulated by Competing Endogenous RNAs in Diverse Human Cancers

MicroRNAs (miRNAs) consist of a large family of small, non-coding RNAs with the ability to result in gene silencing post-transcriptionally. With recent advances in research technology over the past several years, the physiological and pathological potentials of miRNAs have been gradually uncovered. MiR-149-5p, a conserved miRNA, was found to regulate physiological processes, such as inflammatory response, adipogenesis and cell proliferation. Notably, increasing studies indicate miR-149-5p may act as an important regulator in solid tumors, especially cancers in reproductive system and digestive system. It has been acknowledged that miR-149-5p can function as an oncogene or tumor suppressor in different cancers, which is achieved by controlling a variety of genes expression and adjusting downstream signaling pathway. Moreover, the levels of miR-149-5p are influenced by several newly discovered long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). However, there is blank about systematic function and mechanism of miR-149-5p in human cancers. In this review, we firstly summarize the present comprehension of miR-149-5p at the molecular level, its vital role in tumor initiation and progression, as well as its potential roles in monitoring diverse reproductive and digestive malignancies.

Targeting mutant p53 for cancer therapy: direct and indirect strategies

TP53 is a critical tumor-suppressor gene that is mutated in more than half of all human cancers. Mutations in TP53 not only impair its antitumor activity, but also confer mutant p53 protein oncogenic properties. The p53-targeted therapy approach began with the identification of compounds capable of restoring/reactivating wild-type p53 functions or eliminating mutant p53. Treatments that directly target mutant p53 are extremely structure and drug-species-dependent. Due to the mutation of wild-type p53, multiple survival pathways that are normally maintained by wild-type p53 are disrupted, necessitating the activation of compensatory genes or pathways to promote cancer cell survival. Additionally, because the oncogenic functions of mutant p53 contribute to cancer proliferation and metastasis, targeting the signaling pathways altered by p53 mutation appears to be an attractive strategy. Synthetic lethality implies that while disruption of either gene alone is permissible among two genes with synthetic lethal interactions, complete disruption of both genes results in cell death. Thus, rather than directly targeting p53, exploiting mutant p53 synthetic lethal genes may provide additional therapeutic benefits. Additionally, research progress on the functions of noncoding RNAs has made it clear that disrupting noncoding RNA networks has a favorable antitumor effect, supporting the hypothesis that targeting noncoding RNAs may have potential synthetic lethal effects in cancers with p53 mutations. The purpose of this review is to discuss treatments for cancers with mutant p53 that focus on directly targeting mutant p53, restoring wild-type functions, and exploiting synthetic lethal interactions with mutant p53. Additionally, the possibility of noncoding RNAs acting as synthetic lethal targets for mutant p53 will be discussed.

CircMYH9 drives colorectal cancer growth by regulating serine metabolism and redox homeostasis in a p53-dependent manner

Background

Circular RNAs (circRNAs) play important roles in cancer progression and metabolism regulation. Serine/glycine metabolism supports the growth of cancer cells by contributing to their anabolic demands and epigenome as well as by regulating their redox state. However, the role of circRNA in the regulation of serine/glycine metabolism has not been well elucidated.

Methods

Microarray analysis was used to screen differentially expressed novel circRNAs. qRT-PCR and FISH were utilized to analyzed the expression of circMYH9. CCK8, colony formation and FACS were used to analyze proliferation of colorectal cancer (CRC) cells. Xenograft experiments were used to analyze tumor growth in vivo. RNA-sequencing, immunoblot and LC–MS were used to identify the downstream metabolic pathway of circMYH9. ChIRP, Mass Spectrometry, RIP and RNA pulldown were utilized to test the interaction between circMYH9, hnRNPA2B1 and p53 pre-mRNA. ChIP-qPCR was used to analyze the binding sites of HIF-1α. Chemically-induced CRC mice were generated to evaluate the role of circMYH9 in tumorigenesis.

Results

We identified an intron-derived circRNA, circMYH9, which was significantly upregulated in CRC tissues. A higher circMYH9 level correlated with shorter relapse-free survival and overall survival of CRC patients. CircMYH9 promoted serine/glycine metabolism, the NAD + /NADH ratio, and glutathione recycling and inhibited reactive oxygen species (ROS) in a p53-dependent manner, impacting tumour growth. Mechanistically, circMYH9 destabilized the pre-mRNA of p53 by recruiting hnRNPA2B1 in the nucleus. hnRNPA2B1 bound to N6-methyladenosine sites on the 3' untranslated region of p53 pre-mRNA and maintained its stability. Moreover, a lack of amino acids led to an elevated level of ROS, resulting in increased HIF1α, which promoted circMYH9 expression by binding to the promoter region. Furthermore, in vivo AAV9-mediated transfection of circMYH9 could drive chemically-induced carcinogenesis by suppressing p53 in mice.

Conclusions

The overexpression of circMYH9 promotes CRC proliferation though modulating serine/glycine metabolism and redox homeostasis in a p53-dependent manner, and targeting circMYH9 and its pathway may be an effective strategy for the treatment of CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01412-9.

The Molecular Networks of microRNAs and Their Targets in the Drug Resistance of Colon Carcinoma

Simple Summary

We systematically reviewed the recent scientific publications describing the role of microRNAs in the regulation of drug resistance in colon cancer. To clarify the intricate web of resulting genetic and biochemical interactions, we used a machine learning approach aimed at creating: (i) networks of validated miRNA/target interactions involved in drug resistances and (ii) drug-centric networks, from which we identified the major clusters of proteins affected by drugs used in the treatment of colon cancer. Finally, to facilitate a high-level interpretation of these molecular interactions, we determined the cellular pathways related with drug resistance and regulated by the miRNAs in colon cancer.

Abstract

Drug resistance is one of the major forces driving a poor prognosis during the treatment and progression of human colon carcinomas. The molecular mechanisms that regulate the diverse processes underlying drug resistance are still under debate. MicroRNAs (miRNAs) are a subgroup of non-coding RNAs increasingly found to be associated with the regulation of tumorigenesis and drug resistance. We performed a systematic review of the articles concerning miRNAs and drug resistance in human colon cancer published from 2013 onwards in journals with an impact factor of 5 or higher. First, we built a network with the most studied miRNAs and targets (as nodes) while the drug resistance/s are indicated by the connections (edges); then, we discussed the most relevant miRNA/targets interactions regulated by drugs according to the network topology and statistics. Finally, we considered the drugs as nodes in the network, to allow an alternative point of view that could flow through the treatment options and the associated molecular pathways. A small number of microRNAs and proteins appeared as critically involved in the most common drugs used for the treatment of patients with colon cancer. In particular, the family of miR-200, miR34a, miR-155 and miR-17 appear as the most relevant microRNAs. Thus, regulating these miRNAs could be useful for interfering with some drug resistance mechanisms in colorectal carcinoma.

Identification of Ferroptosis-Related Long Noncoding RNA and Construction of a Novel Prognostic Signature for Gastric Cancer

Background

Gastric cancer is the most common malignant tumor of the digestive system. It has a poor prognosis and is clinically challenging to treat. Ferroptosis is a newly defined mode of programmed cell death. The roles and prognostic value of ferroptosis-related long noncoding RNAs (lncRNAs) in gastric cancer remain unknown.

Results

In the current study, 20 ferroptosis-related lncRNAs were identified via univariate Cox analysis, least absolute shrinkage, and selection operator Cox regression analysis and used to construct a prognostic signature and classify gastric cancer patients into high-risk and low-risk groups. The signature was validated using TCGA training and testing cohorts. The risk signature was an independent prognostic indicator of survival and accurately predicted the prognoses of patients with gastric cancer. It was also associated with immune cell infiltration. Gene set enrichment analysis was used to investigate underlying mechanisms that the 20 ferroptosis-related lncRNAs were involved in. Chemosensitivity and immune checkpoint inhibitor analyses indicated that high-risk patients were more sensitive to the immune checkpoint inhibitor programmed cell death protein 1.

Conclusions

The important role of ferroptosis-related lncRNAs in immune infiltration identified in the current study may assist the determination of personalized prognoses and treatments in patients with gastric cancer. These 20 lncRNAs can be used as the diagnostic and prognostic markers for gastric cancer.

Long intergenic non-protein coding RNA 460: Review of its role in carcinogenesis

Long intergenic non-coding RNAs (lincRNAs) establish a group of long non-coding RNAs (lncRNAs) that have no overlap with protein-coding genes. These transcripts have been found to affect chromatin configurations, arrange high-order nuclear structures, function as scaffolds for proteins and RNAs and serve as molecular decoys. LINC00460 is a member of this group of lincRNAs that participate in the pathoetiology of cancers. This lincRNA has been found to serve as a sponge for a number of tumor suppressor miRNAs, including miR-539, miR-1224-5p, miR-612, miR-342-3p, miR-485-5p and miR-149-5p, and increase expression of oncogenic targets of these miRNAs. Moreover, through targeting miRNAs that regulate sensitivity to chemotherapeutic agents, it can affect response of cancer cells to these agents. In the current manuscript, we tended to describe the role of LINC00460 in this process through summarizing the results of in vitro, in vivo and human studies.

The lncRNA OGFRP1/miR-149-5p/IL-6 axis regulates prostate cancer chemoresistance

BACKGROUND

The long non-coding RNA (lncRNA) OGFRP1 has been found to promote malignancy in prostate cancer (PC) and other cancer types. How this lncRNA functions in the regulation of PC chemoresistance, however, is poorly defined.

METHODS

qRT-PCR was employed to measure OGFRP1, miR-149-5p, and IL-6 expression in PC tissues and cells. IC50 values for paclitaxel and docetaxel in PC cells were assessed via a CCK-8 assay approach. Putative miR-149-5p binding targets were identified and validated through bioinformatics assays and luciferase reporter assays, respectively. The impact of OGFRP1 on PC chemoresistance in vivo was validated using a xenograft model system.

RESULTS

Docetaxel-resistant PC (PC/DR) cells and tissues exhibited reduced OGFRP1 expression and increased miR-149-5p expression. Knocking down OGFRP1 augmented the sensitivity of these PC cells to docetaxel and paclitaxel in vitro and in vivo. Mechanistically, OGFRP1 was found to bind and sequester miR-149-5p within PC/DR cells, thereby indirectly regulating IL-6 expression. Consistent with this model, the overexpression of IL-6 reversed the OGFRP1 knockdown-mediated reductions in docetaxel and paclitaxel IC50 values for these PC cells.

CONCLUSIONS

OGFRP1 can sequester miR-149-5p, thereby indirectly promoting IL-6 upregulation and thereby promoting chemoresistance in PC cells. This OGFRP1/miR-149-5p/IL-6 axis may thus be a promising target for therapeutic efforts aimed at PC chemosensitization and treatment.

Development and Interpretation of a Genomic Instability Derived lncRNAs Based Risk Signature as a Predictor of Prognosis for Clear Cell Renal Cell Carcinoma Patients

Background

Clear cell renal cell carcinoma (ccRCC) is a kind of frequently diagnosed cancer, leading to high death rate in patients. Genomic instability (GI) is regarded as playing indispensable roles in tumorigenesis and impacting the prognosis of patients. The aberrant regulation of long non-coding RNAs (lncRNAs) is a main cause of GI. We combined the somatic mutation profiles and expression profiles to identify GI derived lncRNAs (GID-lncRNAs) in ccRCC and developed a GID-lncRNAs based risk signature for prognosis prediction and medication guidance.

Methods

We decided cases with top 25% cumulative number of somatic mutations as genomically unstable (GU) group and last 25% as genomically stable (GS) group, and identified differentially expressed lncRNAs (GID-lncRNAs) between two groups. Then we developed the risk signature with all overall survival related GID-lncRNAs with least absolute shrinkage and selection operator (LASSO) Cox regression. The functions of the GID-lncRNAs were partly interpreted by enrichment analysis. We finally validated the effectiveness of the risk signature in prognosis prediction and medication guidance.

Results

We developed a seven-lncRNAs (LINC00460, AL139351.1, AC156455.1, AL035446.1, LINC02471, AC022509.2, and LINC01606) risk signature and divided all samples into high-risk and low-risk groups. Patients in high-risk group were in more severe clinicopathologic status (higher tumor grade, pathological stage, T stage, and more metastasis) and were deemed to have less survival time and lower survival rate. The efficacy of prognosis prediction was validated by receiver operating characteristic analysis. Enrichment analysis revealed that the lncRNAs in the risk signature mainly participate in regulation of cell cycle, DNA replication, material metabolism, and other vital biological processes in the tumorigenesis of ccRCC. Moreover, the risk signature could help assess the possibility of response to precise treatments.

Conclusion

Our study combined the somatic mutation profiles and the expression profiles of ccRCC for the first time and developed a GID-lncRNAs based risk signature for prognosis predicting and therapeutic scheme deciding. We validated the efficacy of the risk signature and partly interpreted the roles of the seven lncRNAs composing the risk signature in ccRCC. Our study provides novel insights into the roles of genomic instability derived lncRNAs in ccRCC.

The Mechanistic Roles of ncRNAs in Promoting and Supporting Chemoresistance of Colorectal Cancer

Colorectal Cancer (CRC) is one of the most common gastrointestinal malignancies which has quite a high mortality rate. Despite the advances made in CRC treatment, effective therapy is still quite challenging, particularly due to resistance arising throughout the treatment regimen. Several studies have been carried out to identify CRC chemoresistance mechanisms, with research showing different signalling pathways, certain ATP binding cassette (ABC) transporters and epithelial mesenchymal transition (EMT), among others to be responsible for the failure of CRC chemotherapies. In the last decade, it has become increasingly evident that certain non-coding RNA (ncRNA) families are involved in chemoresistance. Research investigations have demonstrated that dysregulation of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) contribute towards promoting resistance in CRC via different mechanisms. Considering the currently available data on this phenomenon, a better understanding of how these ncRNAs participate in chemoresistance can lead to suitable solutions to overcome this problem in CRC. This review will first focus on discussing the different mechanisms of CRC resistance identified so far. The focus will then shift onto the roles of miRNAs, lncRNAs and circRNAs in promoting 5-fluorouracil (5-FU), oxaliplatin (OXA), cisplatin and doxorubicin (DOX) resistance in CRC, specifically using ncRNAs which have been recently identified and validated under in vivo or in vitro conditions.

LINC00460/DHX9/IGF2BP2 complex promotes colorectal cancer proliferation and metastasis by mediating HMGA1 mRNA stability depending on m6A modification

Background

Increasing studies have shown that long noncoding RNAs (lncRNAs) are pivotal regulators participating in carcinogenic progression and tumor metastasis in colorectal cancer (CRC). Although lncRNA long intergenic noncoding RNA 460 (LINC00460) has been reported in CRC, the role and molecular mechanism of LINC00460 in CRC progression still requires exploration.

Methods

The expression levels of LINC00460 were analyzed by using a tissue microarray containing 498 CRC tissues and their corresponding non-tumor adjacent tissues. The correlations between the LINC00460 expression level and clinicopathological features were evaluated. The functional characterization of the role and molecular mechanism of LINC00460 in CRC was investigated through a series of in vitro and in vivo experiments.

Results

LINC00460 expression was increased in human CRC, and high LINC00460 expression was correlated with poor five-year overall survival and disease-free survival. LINC00460 overexpression sufficiently induced the epithelial–mesenchymal transition and promoted tumor cell proliferation, migration, and invasion in vitro and tumor growth and metastasis in vivo. In addition, LINC00460 enhanced the protein expression of high-mobility group AT-hook 1 (HMGA1) by directly interacting with IGF2BP2 and DHX9 to bind the 3′ untranslated region (UTR) of HMGA1 mRNA and increased the stability of HMGA1 mRNA. In addition, the N6-methyladenosine (m6A) modification of HMGA1 mRNA by METTL3 enhanced HMGA1 expression in CRC. Finally, it suggested that HMGA1 was essential for LINC00460-induced cell proliferation, migration, and invasion.

Conclusions

LINC00460 may be a novel oncogene of CRC through interacting with IGF2BP2 and DHX9 and bind to the m6A modified HMGA1 mRNA to enhance the HMGA1 mRNA stability. LINC00460 can serve as a promising predictive biomarker for the diagnosis and prognosis among patients with CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01857-2.