Long Noncoding RNA LINC00857 Promotes Proliferation, Migration, and Invasion of Colorectal Cancer Cell through miR-1306/Vimentin Axis

LncRNA PRBC induces autophagy to promote breast cancer progression through modulating PABPC1-mediated mRNA stabilization

Breast cancer is one of the major malignant tumors among women worldwide. Long noncoding RNAs (lncRNAs) have been documented as significant modulators in the development and progression of various cancers; however, the contribution of lncRNAs to breast cancer remains largely unknown. In this study, we found a novel lncRNA (NONHSAT137675) whose expression was significantly increased in the breast cancer tissues. We named the novel lncRNA as lncRNA PRBC (PABPC1-related lncRNA in breast cancer) and identified it as a key lncRNA associated with breast cancer progression and prognosis. Functional analysis displayed that lncRNA PRBC could promote autophagy and progression of breast cancer. Mechanistically, we verified that lncRNA PRBC physically interacted with PABPC1 through RIP assay, and PABPC1 overexpression could reverse the inhibiting effect of lncRNA PRBC knockdown on the malignant behaviors in breast cancer cells. Knockdown of lncRNA PRBC interfered the translocation of PABPC1 from nucleus to cytoplasm as indicated by western blot and IF assays. Significantly, the cytoplasmic location of PABPC1 was required for the interaction between PABPC1 and AGO2, which could be enhanced by lncRNA PRBC overexpression, leading to strengthened recruitment of mRNA to RNA-induced silencing complex (RISC) and thus reinforcing the inhibition efficiency of miRNAs. In general, lncRNA PRBC played a critical role in malignant progression of breast cancer by inducing the cytoplasmic translocation of PABPC1 to further regulate the function of downstream miRNAs. This study provides novel insight on the molecular mechanism of breast cancer progression, and lncRNA PRBC might be a promising therapeutic target and prognostic predictor for breast cancer.

Retracted: Long Noncoding RNA LINC00857 Promotes Proliferation, Migration, and Invasion of Colorectal Cancer Cell through miR-1306/Vimentin Axis

[This retracts the article DOI: 10.1155/2021/5525763.].

The role of microRNA-185 in the pathogenesis of human diseases: A focus on cancer

MicroRNAs (miRNAs) are a widely-studied class of non-coding RNAs characterized by their short length (18-25 nucleotides). The precise functions of miRNAs are not well-elucidated; however, an increasing number of studies suggest their involvement in various physiologic processes and deregulation in pathologic conditions. miRNA-185 (miR-185) is among the mostly-studied miRNAs in human diseases, which is found to play putative roles in conditions like metabolic disorders, asthma, frailty, schizophrenia, and hepatitis. Notably, many cancer studies report the downregulation of miR-185 in cell lines, tumor tissues, and plasma specimens of patients, while it demonstrates a suppressing role on the malignant properties of cancer cells in vitro and in vivo. Accordingly, miR-185 can be considered a tumor suppressor miRNA in human malignancies, while a few studies also report inconsistent findings. Being suggested as a prognostic/diagnostic biomarker, mi-185 is also found to offer clinical potentials, particularly for early diagnosis and prediction of the prognosis of cancer patients. In this review, we have outlined the studies that have evaluated the functions and clinical significance of miR-185 in different human diseases with a particular focus on cancer.

Clinical significance of long non-coding RNA ZEB2-AS1 and EMT-related markers in ductal and lobular breast cancer

BACKGROUND

Breast cancer is considered the most prevalent type of cancer in women and accounts for a high rate of death. A body of research has demonstrated that lncRNAs have a regulatory function in human diseases, especially cancers. ZEB2-AS1 is known as an oncogenic lncRNA in various types of cancers, and its deregulation may contribute to cancer development and progression. Therefore, we aimed to reveal the association of ZEB2-AS1 expression with epithelial-mesenchymal transition (EMT) markers, as a hallmark of cancer progression, in a clinical setting.

METHODS

A recent study suggested that ZEB2-AS1 is significantly involved in EMT. Here we intended to explore the roles of lncRNA ZEB2-AS1 in breast cancer (BC) using bioinformatics tools and laboratory settings. We first evaluated the expression of ZEB2-AS1 mRNA in tumor and healthy control tissues by lnCAR database. Furthermore, ZEB2-AS1 expression level, ZEB2, E-cadherin, and vimentin was measured via qRT-PCR in 30 paired ductal and lobular carcinoma tissues from breast cancer patients and the normal adjacent ones. The correlation between the lncRNA ZEB2-AS1 expression and clinicopathological characteristics of the breast cancer patients was evaluated.

RESULTS

ZEB2-AS1 showed an upregulation in breast cancer tissues (p = .04) compared to normal adjacent samples. In addition, its level was higher in breast cancer patients with advanced Stages (III & IV) (n = 18) compared to early Stages (I & II) (n = 12) (p = .04). Moreover, ZEB2 (p = .01) and vimentin (p = .02) expression were upregulated in the BC sample, but the expression level of E-cadherin (p = .02) was downregulated when compared with the adjacent normal tissues. By comparison of the expression of EMT-markers between different stages of breast cancer, overexpression of ZEB2 (p = .04) and vimentin (p = .04) and down expression of E-cadherin (p = .03) was observed in advance stages.

CONCLUSIONS

Collectively, our findings suggest that ZEB2-AS1 expression is significantly upregulated in tumor tissues, especially in advanced stages and ZEB2-AS1 is associated with the aggressiveness of tumors by functioning as putative oncogenic lncRNA. In addition, a combination of ZEB2-AS1 and these EMT markers in breast cancer potentiates these genes as biomarkers for tumor progression.

Identification of a apoptosis-related LncRNA signature to improve prognosis prediction and immunotherapy response in lung adenocarcinoma patients

Apoptosis is closely associated with the development of various cancers, including lung adenocarcinoma (LUAD). However, the prognostic value of apoptosis-related lncRNAs (ApoRLs) in LUAD has not been fully elucidated. In the present study, we screened 2, 960 ApoRLs by constructing a co-expression network of mRNAs-lncRNAs associated with apoptosis, and identified 421 ApoRLs that were differentially expressed between LUAD samples and normal lung samples. Sixteen differentially expressed apoptosis-related lncRNAs (DE-ApoRLs) with prognostic relevance to LUAD patients were screened using univariate Cox regression analysis. An apoptosis-related lncRNA signature (ApoRLSig ) containing 10 ApoRLs was constructed by applying the Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression method, and all LUAD patients in the TCGA cohort were divided into high or low risk groups. Moreover, patients in the high-risk group had a worse prognosis (p < 0.05). When analyzed in conjunction with clinical features, we found ApoRLSig to be an independent predictor of LUAD patients and established a prognostic nomogram combining ApoRLSig and clinical features. Gene set enrichment analysis (GSEA) revealed that ApoRLSig is involved in many malignancy-associated immunomodulatory pathways. In addition, there were significant differences in the immune microenvironment and immune cells between the high-risk and low-risk groups. Further analysis revealed that the expression levels of most immune checkpoint genes (ICGs) were higher in the high-risk group, which suggested that the immunotherapy effect was better in the high-risk group than in the low-risk group. And we found that the high-risk group was also better than the low-risk group in terms of chemotherapy effect. In conclusion, we successfully constructed an ApoRLSig which could predict the prognosis of LUAD patients and provide a novel strategy for the antitumor treatment of LUAD patients.

Identification of a prognostic classifier based on EMT-related lncRNAs and the function of LINC01138 in tumor progression for lung adenocarcinoma

Purpose: This study aimed to develop a prognostic indicator based on epithelial-mesenchymal transition (EMT)-related long noncoding RNAs (lncRNAs) and explore the function of EMT-related lncRNAs in malignant progression in lung adenocarcinoma (LUAD).

Materials and methods: A LUAD dataset was acquired from The Cancer Genome Atlas (TCGA) to identify prognostic EMT-related lncRNAs via differential expression analysis and univariate Cox regression analysis. Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression analysis was utilized for variable selection and model construction. The EMT-related prognostic index (ERPI) was calculated according to the model and served as a classifier to divide LUAD individuals into high-ERPI and low-ERPI groups. A nomogram incorporating ERPI and clinicopathological variables was constructed. TCGA-LUAD, GSE50081, and GSE31210 were used to test the predictive capacity of the ERPI and nomogram. The characteristics of the tumor microenvironment (TME) were evaluated via the ESTIMATE, TIMER, and ssGSEA algorithms. Gene set variation analysis (GSVA) and ssGSEA were used to annotate the functions of the high-ERPI and low-ERPI groups. CCK8, transwell assay, wound-healing assay, and clone formation assay were conducted to clarify the biological functions of prognostic EMT-related lncRNAs.

Results: Ninety-seven differentially expressed EMT-related lncRNAs were identified, 15 of which were related to overall survival (OS). A prognostic signature was constructed based on 14 prognostic EMT-related lncRNAs to calculate the ERPI of each patient, and the predictive ability of ERPI was verified in TCGA, GSE50081, and GSE31210. The low-ERPI group survived longer and had a lower percentage of patients in advanced stage than the high-ERPI group. The nomogram had the highest predictive accuracy, followed by ERPI and stage. Patients with low ERPI had higher infiltration degree of immune cells and stronger immune responses than those with high ERPI. A series of in vitro experiments demonstrated that knockdown of LINC01138 dampened variability, proliferation, and motility of A549 and H460 cells.

Conclusion: Our study developed a prognostic classifier with robust prognostic performance and clarified the biological functions of LINC01138 in LUAD, aiding in making individual treatments for patients with LUAD and dissecting the mechanism of oncogenesis.

HSF1 Stimulates Glutamine Transport by Super-Enhancer-Driven lncRNA LINC00857 in Colorectal Cancer

Simple Summary

Based on the latest research, cancer cells prefer glutamine to glucose. Therefore, it is more worthwhile to explore the regulatory mechanism of glutamine metabolism in cancer cells. Super enhancers are critical for the gene transcriptional programs responsible for cell fate by interacting with various transcription factors. The transcription factor HSF1 exerts a multifaced role in tumorigenesis. However, the relevance of HSF1 to super enhancers in tumors remains obscure. Therefore, this study focused on the mechanism underlying super-enhancer activation and its relationship to HSF1 in CRC. Here, we performed a super-enhancer landscape in CRC and we screened out an HSF1-mediated super enhancer, lncRNA-LINC00857, by lncRNA microarray. We discovered that HSF1 could stimulate acetyltransferase P300-mediated super-enhancer activity to facilitate LINC00857 expression, contributing to SLC1A5/ASCT2-mediated glutamine transport. In addition, we validated that targeting the HSF1/LINC00857/ANXA11 axis may provide a valuable therapeutic strategy against CRC.

Abstract

Super enhancers are critical for the gene transcription responsible for cell fate by interacting with transcription factors. However, the relevance of HSF1 to super enhancers in tumors remains obscure. We profiled H3K27ac enrichment by chromatin immunoprecipitation sequencing. HSF1-mediated lncRNAs were identified by lncRNA microarray. The characteristics of LINC00857 were explored by in vitro and in vivo assays. The mechanism was studied via chromatin immunoprecipitation, RNA immunoprecipitation, and HSF1/ANXA11 knockout mice. We found that super enhancers occupied multiple gene loci in colorectal cancer. We screened out an HSF1-mediated super enhancer, lncRNA-LINC00857, which exerts its characteristics in promoting cell growth via regulating glutamine metabolism. Notably, HSF1 could stimulate the super-enhancer activity of LINC00857 by the enrichment of acetyltransferase P300 to its gene loci, contributing to LINC00857 transcription. In turn, nuclear LINC00857 cooperated with HSF1 to promote ANXA11 transcription, which modulated SLC1A5/ASCT2 protein expression by binding competitively to miR-122-5p. The knockout of ANXA11 attenuated colorectal cancer formation in vivo. Collectively, we shed light on a closely cooperative machinery between HSF1 and super enhancers. HSF1 could stimulate acetyltransferase P300-mediated super-enhancer activity to facilitate LINC00857 expression, contributing to SLC1A5-mediated glutamine transport. Targeting the HSF1/LINC00857/ANXA11 axis may provide a valuable therapeutic strategy against colorectal cancer.

β-Hydroxyisovaleryl-Shikonin Exerts an Antitumor Effect on Pancreatic Cancer Through the PI3K/AKT Signaling Pathway

Pancreatic cancer (PC) is marked with a low survival rate and lack of recognized effective treatment strategy. We investigated the antitumor effect of β-hydroxyisovaleryl-shikonin (β-HIVS) on PC and the associated working mechanism. Cell toxicity was determined using Cell Counting Kit-8 (CCK-8) assay. Acridine Orange/Ethidium Bromide (AO/EB) double-fluorescent staining assay accompanied by flow cytometry was utilized to estimate cell apoptosis. Cell cycle, reactive oxygen species (ROS), and mitochondrial membrane potential were all evaluated using flow cytometry. Transwell and wound healing assays were performed to evaluate cell migration and invasion. Protein expression was analyzed by Western blots. A xenograft mouse model was employed to determine the antitumor effect of β-HIVS in vivo. PC cell viability gradually decreased with increasing β-HIVS while apoptosis was enhanced together with cell-cycle blockage in the G0–G1 phases. β-HIVS induced mitochondrial dysfunction, ROS production, and DNA damage and inhibited the invasive and migratory ability of PC cells. We further confirmed the suppression of EMT and PI3K/AKT pathways as underlying mechanisms. The mouse model treated with the increasing dose of β-HIVS displayed decreased tumor growth rate, along with increased apoptosis. Thus, β-HIVS exerts antitumor effects on PC through inducing apoptosis, ROS production, decreasing mitochondrial membrane potential, and suppressing signal pathways, such as PI3K/AKT. In summary, β-HIVS might be a promising strategy for PC treatment.

LINC00857 promotes colorectal cancer progression by sponging miR-150-5p and upregulating HMGB3 (high mobility group box 3) expression

Colorectal cancer (CRC) is the third most commonly diagnosed malignant tumor worldwide. LINC00857 has been reported as a dysregulated long non-coding RNAs (lncRNAs) involved in the genesis and development of different cancers. In CRC, accumulating evidence indicates that high mobility group box 3 (HMGB3) is over-expressed and contributes to CRC development. However, the mechanism underlying HMGB3 upregulation in CRC remains unclear. The present work aims to investigate the role of LINC00857 and its functional interaction with HMGB3 in regulating CRC progression. Differential expression of LINC00857 between CRC tissues and normal tissues was identified in TCGA (The Cancer Genome Atlas) database. In vitro functional assays were performed to explore the biological functions of LINC00857 in CRC cells. In vivo xenograft model was employed to investigate the role of LINC00857 in CRC tumorigenesis. We found that LINC00857 was significant upregulated in CRC tissues and cell lines. LINC00857 knockdown significantly inhibited the proliferation, migration and invasion of CRC cells, and also induced apoptosis. Moreover, LINC00857 knockdown suppressed CRC tumorigenesis in vivo. We further demonstrated that the effects of LINC00857 in CRC cells were mediated through miR-150-5p/HMGB3 axis. LINC00857 negatively regulates the activity of miR-150-5p, which releases its inhibition on HMGB3 expression. Our data indicate that LINC00857/miR-150-5p/HMGB3 axis plays a fundamental role in regulating the malignant phenotype and tumorigenesis of CRC. Targeting this axis may serve as novel therapeutic strategies for CRC treatment.