LINC00565 promotes proliferation and inhibits apoptosis of gastric cancer by targeting miR-665/AKT3 axis

Classical biomarkers and non-coding RNAs associated with diagnosis and treatment in gastric cancer

One of the most prevalent malignant tumors worldwide, stomach cancer still has a high incidence and fatality rate in China, and the number of young people developing early-onset gastric cancer is steadily increasing. The 5-year survival rate of stomach cancer is typically 30%-35%, the prognosis is bad, the patients' quality of life is low, and the progression of advanced gastric cancer cannot be effectively managed despite the use of surgical surgery, chemotherapy, and other medicines. We urgently need molecular biomarkers with high specificity and sensitivity to increase the early gastric cancer detection rate, extend patient survival, and improve patient quality of life. The initial diagnosis of gastric cancer primarily depends on gastroscopy and biopsy, and invasive procedures cause significant discomfort to patients. Similar to this, treating advanced and metastatic stomach cancer is a pressing issue that requires attention. More and more immune checkpoint molecules have been discovered, and corresponding inhibitors are gradually being applied to clinical diagnosis and treatment. Recently, some non-coding RNAs have begun to be used as new targets for the treatment of gastric cancer. Some non-coding RNAs are highly present in the serum or urine of gastric cancer patients and can be used as diagnostic markers or prognostic indicators. Many clinical trials targeting non-coding RNAs have also shown good therapeutic effects. In general, targeting non-coding RNAs has shown good therapeutic effects. The biomarkers for gastric cancer detection and treatment are reviewed in this article, focusing on the new non-coding RNAs used in diagnosis, prognosis, and treatment. Patients with stomach cancer should have access to more precise and efficient diagnosis and treatment choices as a result of ongoing technological advancements and thorough research.

Long non-coding RNA LINC00565 regulates ADAM19 expression through sponging microRNA-532-3p, thereby facilitating clear cell renal cell carcinoma progression

Proven by publications, long non-coding RNAs (lncRNAs) play critical roles in the development of clear cell renal cell carcinoma (ccRCC). Although lncRNA LINC00565 has been implicated in the progression of various cancers, its biological effects on ccRCC remain unknown. This study aimed to investigate the biological functions of LINC00565, as well as its potential mechanism in ccRCC. Here, the expression data of mature microRNAs (miRNAs) (normal: 71, tumor: 545), messenger RNAs (mRNAs), and lncRNAs (normal: 72, tumor: 539) of ccRCC were acquired from The Cancer Genome Atlas (TCGA) database and subjected to differential expression analysis. Quantitative reverse transcriptase polymerase chain reaction analyzed the expression levels of LINC00565, miR-532-3p, and ADAM19 mRNA. TCGA database, dual-luciferase report detection, and Argonaute 2 RNA immunoprecipitation were utilized to confirm the relationships between LINC00565 and miR-532-3p and between miR-532-3p and ADAM19, respectively. The progression of ccRCC cells was determined via CCK-8, colony formation, scratch healing, and transwell assays. Western blot was applied to detect the protein levels of epithelial-mesenchymal transition markers and ADAM19. We herein suggested that LINC00565 was prominently upregulated in ccRCC tissues and cells. Knockdown of LINC00565 repressed cell progression. We further predicted and validated miR-532-3p as a target of LINC00565, and miR-532-3p could target ADAM19. Knockdown of LINC00565 resulted in ADAM19 level downregulation in ccRCC cells and suppressed miR-532-3p could restore ADAM19 level. Thus, the three RNAs constructed a ceRNA network. Overexpressed ADAM19 could eliminate the anticancer effects caused by knocking down LINC00565 on ccRCC cells. In conclusion, LINC00565 upregulated ADAM19 via absorbing miR-532-3p, thereby facilitating the progression of ccRCC cells.

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

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

Construction of a cuproptosis-related lncRNA signature for predicting prognosis and immune landscape in osteosarcoma patients

BACKGROUND

Long noncoding RNAs (lncRNAs) influence the onset of osteosarcoma. Cuproptosis is a novel cell death mechanism. We attempted to identify a cuproptosis-related lncRNA signature to predict the prognosis and immune landscape in osteosarcoma patients.

METHODS

Transcriptional and clinical data of 85 osteosarcoma patients were derived from the TARGET database and randomly categorized into the training and validation cohorts. We implemented the univariate and multivariate Cox regression, along with LASSO regression analyses for developing a cuproptosis-related lncRNA risk model. Kaplan-Meier curves, C-index, ROC curves, univariate and multivariate Cox regression, and nomogram were used to assess the capacity of this risk model to predict the osteosarcoma prognosis. Gene ontology, KEGG, and Gene Set Enrichment (GSEA) analyses were conducted for determining the potential functional differences existing between the high-risk and low-risk patients. We further conducted the ESTIMATE, single-smaple GSEA, and CIBERSORT analyses for identifying the different immune microenvironments and immune cells infiltrating both the risk groups.

RESULTS

We screened out four cuproptosis-related lncRNAs (AL033384.2, AL031775.1, AC110995.1, and LINC00565) to construct the risk model in the training cohort. This risk model displayed a good performance to predict the overall survival of osteosarcoma patients, which was confirmed by using the validation and the entire cohort. Further analyses showed that the low-risk patients have more immune activation and immune cells infiltrating as well as a good response to immunotherapy.

CONCLUSIONS

We developed a novel cuproptosis-related lncRNA signature with high reliability and accuracy for predicting outcome and immunotherapy response in osteosarcoma patients, which provides new insights into the personalized treatment of osteosarcoma.

Clinicopathological and prognostic value of long non-coding RNA CCAT1 expression in patients with digestive system cancer

Colon cancer associated transcript-1 (CCAT1) is known to play an important role in numerous types of human cancer, including bladder, prostate and ovarian cancer. However, a consistent perspective has not been established in digestive system cancer (DSC). To explore the prognostic value of CCAT1 in patients with DSC, a meta-analysis was performed. A systematic search of PubMed, Embase, Web of Science, China National Knowledge Infrastructure, Chinese Biological Medical Literature database, Cochrane Library and WanFang database was applied to select eligible articles. Pooled odds ratios (ORs) or hazard ratios (HRs) with corresponding 95% confidence intervals (CIs) were calculated to estimate the effects of CCAT1 on pathological or clinical features. A total of 1,719 patients from 12 eligible articles were enrolled in the meta-analysis. The results revealed that elevated CCAT1 expression was significantly related to larger tumor size (OR, 1.81; 95% CI, 1.31-2.48), poorer differentiation (OR, 0.45; 95% CI, 0.31-0.64), earlier lymph node metastasis (OR, 3.14; 95% CI, 2.34-4.22) and advanced TNM stage (OR, 3.08; 95% CI, 2.07-4.59). In addition, high CCAT1 expression predicted a poorer outcome for overall survival rate (HR, 2.37; 95% CI, 2.11-2.67) and recurrence-free survival rate (HR, 2.16, 95% CI, 1.31-3.57). High expression levels of CCAT1 were therefore related to unfavorable clinical outcomes of patients with DSC. These results demonstrated that CCAT1 could serve as a prognostic predictor in human DSC.

LncRNA RPSAP52 promotes cell proliferation and inhibits cell apoptosis via modulating miR-665/STAT3 in gastric cancer

LncRNA RPSAP52 is a newly identified functional molecular in several cancers, but its role in gastric cancer (GC) is currently unclear. This study aimed to investigate the biofunction of lncRNA RPSAP52 in GC. Quantitative polymerase-chain reaction (RT-qPCR) was employed to analyze the gene level of lncRNA RPSAP52 and miR-665. Cell proliferation capacity was evaluated via CCK-8 and colony formation assay. Flow cytometry was applied to detect cell cycle and cell apoptosis. Hematoxylin-eosin staining was conducted for histopathological analysis. Immunochemical staining was carried out to detect expression level of ki-67. Subcellular fractionation was performed to explore the position of lncRNA RPSAP52. The binding relationship among lncRNA RPSAP52, miR-665 and STAT3 was verified via luciferase reporter assay. RNA pull down experiments were used to verify the binding relationship between lncRNA RPSAP52 and miR-665. The STAT3 level was evaluated via Western blot. LncRNA RPSAP52 is significantly elevated in GC cells. Deletion of lncRNA RPSAP52 restrained cell proliferation and induced G0-G1 phase arrest, while expediting apoptosis in GC cells. Tumor growth in vivo was suppressed following lncRNA RPSAP52 depletion. MiR-665 was verified as the target of lncRNA RPSAP52. A ceRNA-sponge mechanism of lncRNA RPSAP52 on miR-665 was identified. Meanwhile, miR-665 functions as STAT3 sponge. MiR-665 overexpression and STAT3 depletion served the same functions as lncRNA RPSAP52 depletion in GC cells. LncRNA RPSAP52 exerted anti-cancer effects via modulating miR-665/STAT3 in GC.Abbreviations: Gastric cancer (GC); Quantitative polymerase-chain reaction (RT-qPCR); Helicobacter pylori (H. pylori); Roswell Park Memorial Institute 1640 (RPMI 1640); fetal bovine serum (FBS); glyceraldheyde 3-phosphate dehydrogenase (GAPDH); propidium iodide (PI); Cell counting kit-8 (CCK-8); radioimmunoprecipitation assay (RIPA); sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE); polyvinylidene fluoride (PVDF); enhanced chemiluminescence (ECL); Statistical Product and Service Solutions (SPSS); standard deviation (SD).

Long Noncoding RNA Mediated Regulation in Human Embryogenesis, Pluripotency, and Reproduction

Long noncoding RNAs (lncRNAs), a class of noncoding RNAs with more than 200 bp in length, are produced by pervasive transcription in mammalian genomes and regulate gene expression through various action mechanisms. Accumulating data indicate that lncRNAs mediate essential biological functions in human development, including early embryogenesis, induction of pluripotency, and germ cell development. Comprehensive analysis of sequencing data highlights that lncRNAs are expressed in a stage-specific and human/primate-specific pattern during early human development. They contribute to cell fate determination through interacting with almost all classes of cellular biomolecules, including proteins, DNA, mRNAs, and microRNAs. Furthermore, the expression of a few of lncRNAs is highly associated with the pathogenesis and progression of many reproductive diseases, suggesting that they could serve as candidate biomarkers for diagnosis or novel targets for treatment. Here, we review research on lncRNAs and their roles in embryogenesis, pluripotency, and reproduction. We aim to identify the underlying molecular mechanisms essential for human development and provide novel insight into the causes and treatments of human reproductive diseases.

Autophagy and gastrointestinal cancers: the behind the scenes role of long non-coding RNAs in initiation, progression, and treatment resistance

Gastrointestinal (GI) cancers comprise a heterogeneous group of complex disorders that affect different organs, including esophagus, stomach, gallbladder, liver, biliary tract, pancreas, small intestine, colon, rectum, and anus. Recently, an explosion in nucleic acid-based technologies has led to the discovery of long non-coding RNAs (lncRNAs) that have been found to possess unique regulatory functions. This class of RNAs is >200 nucleotides in length, and is characterized by their lack of protein coding. LncRNAs exert regulatory effects in GI cancer development by affecting different functions such as the proliferation and metastasis of cancer cells, apoptosis, glycolysis and angiogenesis. Over the past few decades, considerable evidence has revealed the important role of autophagy in both GI cancer progression and suppression. In addition, recent studies have confirmed a significant correlation between lncRNAs and the regulation of autophagy. In this review, we summarize how lncRNAs play a behind the scenes role in the pathogenesis of GI cancers through regulation of autophagy.

Revealing the role of miRNA-489 as a new onco-suppressor factor in different cancers based on pre-clinical and clinical evidence

Recently, microRNAs (miRNAs) have shown to be potential therapeutic, diagnostic and prognostic targets in disease therapy. These endogenous non-coding RNAs contribute to regulation of different cellular events that are necessary for maintaining physiological condition. Dysregulation of miRNAs is correlated with development of various pathological events such as neurological disorders, cardiovascular diseases, and cancer. miRNA-489 is a new emerging miRNA and studies are extensively investigating its role in pathological conditions. Herein, potential function of miRNA-489 as tumor-suppressor in various cancers is described. miRNA-489 is able to sensitize cancer cells into chemotherapy by disrupting molecular pathways involved in cancer growth such as PI3K/Akt, and induction of apoptosis. The PROX1 and SUZ12 as oncogenic pathways, are affected by miRNA-489 in suppressing metastasis of cancer cells. Wnt/β-catenin as an oncogenic factor ensuring growth and malignancy of tumors is inhibited via miRNA-489 function. For enhancing drug sensitivity of tumors, restoring miRNA-489 expression is a promising strategy. The lncRNAs can modulate miRNA-489 expression in tumors and studies about circRNA role in miRNA-489 modulation should be performed. The expression level of miRNA-489 is a diagnostic tool for tumor detection. Besides, down-regulation of miRNA-489 in tumors provides unfavorable prognosis.

Circular RNA Paired-Related Homeobox 1 Promotes Gastric Carcinoma Cell Progression via Regulating MicroRNA-665/YWHAZ Axis

BACKGROUND

Gastric carcinoma (GC) is a ubiquitous malignant tumor worldwide. Circular RNA paired-related homeobox 1 (circ-PRRX1), one kind of non-coding RNAs, has been reported to act as a promoter in tumor growth. This study aims to explore the effects of circ-PRRX1 on proliferation, apoptosis, and metastasis in GC and the underlying regulatory mechanisms.

METHODS

The expression of circ-PRRX1, miR-665, and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ) mRNA was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was used to analyze YWHAZ protein expression. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-Htetrazolium bromide (MTT), flow cytometry, and transwell assay were carried out to assess the viability, apoptosis, migration, and invasion in GC cells. The interaction between miR-665 and circ-PRRX1 or YWHAZ was predicted by StarBase v2.0 and identified by dual-luciferase reporter system. Xenograft mouse model was employed to determine the effects of circ-PRRX1 knockdown on GC growth in vivo.

RESULTS

Compared with normal tissues and cells, circ-PRRX1 and YWHAZ levels were upregulated, and miR-665 was downregulated in GC tissues and cells. Functionally, circ-PRRX1 knockdown inhibited the viability, migration, and invasion and promoted apoptosis in GC cells, whereas anti-miR-665 abolished these effects. Mechanistically, circ-PRRX1 was confirmed as a sponge of miR-665 to regulate YWHAZ expression. Xenograft mouse model suggested that circ-PRRX1 knockdown reduced GC cells growth in vivo.

CONCLUSION

Circ-PRRX1 knockdown suppressed GC development by targeting miR-665 to inhibit YWHAZ expression, and the potential molecular mechanism may provide a theoretical basis for GC therapy.

Circ_0016760 accelerates non-small-cell lung cancer progression through miR-646/AKT3 signaling in vivo and in vitro

BACKGROUND

Currently, the prognosis of non-small-cell lung cancer (NSCLC) patients remains dismal due to recurrence and metastasis. The purpose of our study was to explore the role of circular RNA_0016760 (circ_0016760) in NSCLC progression and its associated mechanism.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was implemented to measure the expression of circ_0016760, microRNA-646 (miR-646) and AK strain thymoma serine/threonine kinase 3 (AKT3). The protein level of AKT3 was examined by Western blot assay. Cell Counting Kit 8 assay, transwell assays, and flow cytometry were conducted to analyze cell proliferation, metastasis, and apoptosis. Dual-luciferase reporter assay was used to confirm the interactions that were predicted by bioinformatics software (Circular RNA Interactome and TargetScan). A xenograft tumor model was built to investigate the role of circ_0016760 in vivo.

RESULTS

Circ_0016760 and AKT3 were highly expressed in NSCLC tissue specimens and cell lines. Circ_0016760 interference suppressed cell proliferation, migration, and invasion and promoted the apoptosis of NSCLC cells. Circ_0016760 interacted with miR-646 and negatively regulated its expression. MiR-646 silencing partly counteracted circ_0016760 knockdown-mediated influences in NSCLC cells. MiR-646 bound to the AKT3 3' untranslated region in NSCLC cells, and miR-646 overexpression-induced effects in NSCLC cells were partly overturned by the addition of AKT3 overexpression plasmid. Circ_0016760 silencing reduced the expression of AKT3 through enhancing miR-646 expression. Circ_0016760 knockdown suppressed NSCLC tumor growth in vivo.

CONCLUSION

Circ_0016760 played an oncogenic role to promote the proliferation, migration, and invasion and restrained the apoptosis of NSCLC cells via miR-646/AKT3 signaling.

Long Non-coding RNA LINC01503 Promotes Gastric Cardia Adenocarcinoma Progression via miR-133a-5p/VIM Axis and EMT Process

BACKGROUND

LINC01503 has been reported to act as a candidate oncogenic lncRNA in several types of human cancer. However, the functions and underlying mechanisms of LINC01503 in gastric cardia adenocarcinoma (GCA) remain unclear.

AIMS

To investigate the roles and underlying mechanisms of LINC01503 in GCA progression.

MATERIALS AND METHODS

Gene expressions were detected by quantitative real-time PCR (qRT-PCR). Gain-of-function assays were performed to evaluate the function of LINC01503 in gastric cancer cells. Bioinformatics analysis, luciferase reporter assay, and RIP assay were performed to identify associations among LINC01503, miR-133a-5p, and VIM.

RESULTS

The expression level of LINC01503 was significantly elevated in GCA tissues and cell lines. High expression of LINC01503 was correlated with lymph node metastasis, TNM stage, and poor prognosis of GCA patients. Knockdown of LINC01503 significantly reduced proliferation, migration, and invasion ability in GC cells. LINC01503 might function as a competing endogenous RNA (ceRNA) via sponging miR-133a-5p to upregulate the expression of VIM. Furthermore, overexpression of LINC01503 promoted the progression of epithelial mesenchymal transition (EMT) in vitro.

CONCLUSION

LINC01503 serves as an oncogenic lncRNA to promote GCA progression via affecting LINC01503/miR-133a-5p/VIM axis and EMT process. LINC01503 not only has a critical role in GCA progression but also provide a novel potential biomarker in predicting prognosis for GCA patients.

Roles of ncRNAs as ceRNAs in Gastric Cancer

Although ignored in the past, with the recent deepening of research, significant progress has been made in the field of non-coding RNAs (ncRNAs). Accumulating evidence has revealed that microRNA (miRNA) response elements regulate RNA. Long ncRNAs, circular RNAs, pseudogenes, miRNAs, and messenger RNAs (mRNAs) form a competitive endogenous RNA (ceRNA) network that plays an essential role in cancer and cardiovascular, neurodegenerative, and autoimmune diseases. Gastric cancer (GC) is one of the most common cancers, with a high degree of malignancy. Considerable progress has been made in understanding the molecular mechanism and treatment of GC, but GC’s mortality rate is still high. Studies have shown a complex ceRNA crosstalk mechanism in GC. lncRNAs, circRNAs, and pseudogenes can interact with miRNAs to affect mRNA transcription. The study of the involvement of ceRNA in GC could improve our understanding of GC and lead to the identification of potential effective therapeutic targets. The research strategy for ceRNA is mainly to screen the different miRNAs, lncRNAs, circRNAs, pseudogenes, and mRNAs in each sample through microarray or sequencing technology, predict the ceRNA regulatory network, and, finally, conduct functional research on ceRNA. In this review, we briefly discuss the proposal and development of the ceRNA hypothesis and the biological function and principle of ceRNAs in GC, and briefly introduce the role of ncRNAs in the GC’s ceRNA network.

Long non-coding RNA TUG1 aggravates cerebral ischemia and reperfusion injury by sponging miR-493-3p/miR-410-3p

Background

Cerebral ischemia and reperfusion injury (CIRI) affects bodily function by causing irreversible damage to brain cells. The diverse pathophysiological course factors hinder the research work to go deeper. Long noncoding RNA taurine-upregulated gene 1 (TUG1) has been reported to be related to CIRI. This study explored the undefined regulatory pathway of TUG1 in CIRI.

Methods

Quantitative real-time polymerase chain reaction was applied to test the expression of TUG1, microRNA (miR)-493-3p and miR-410-3p. The viability and apoptosis of oxygen and glucose deprivation/reoxygen (OGD/R) model cells were evaluated by cell counting kit-8 and flow cytometry assay, respectively. The determination of inflammatory factors of interleukin-6, interleukin-1β and tumor necrosis factor-α was presented by enzyme-linked immunosorbent assay. The oxidative stress was performed by measuring the generation of malondialdehyde, reactive oxygen species and the activity of superoxide dismutase. Cytotoxicity was presented by measuring the generation of lactate dehydrogenase. Western blot assay was devoted to assessing the level of apoptosis-related factors (cleaved-caspase-3 and cleaved-caspase-9) and the protein level of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK) pathway-related factors in neuro-2a cells treated by OGD/R. Besides, online database starBase was applied to predict the potential binding sites of TUG1 to miR-493-3p and miR-410-3p, which was further confirmed by the dual-luciferase reporter system.

Results

The expression of TUG1 was upregulated, while miR-493-3p or miR-410-3p was downregulated in the serum of CIRI and OGD/R model cells. Meanwhile, knockdown of TUG1 eliminated the suppression in proliferation, the promotion in apoptosis, inflammation and oxidative stress, as well as the cytotoxicity in OGD/R model cells. Interestingly, the inhibition of miR-493-3p or miR-410-3p allayed the above effects. In addition, TUG1 harbored miR-493-3p or miR-410-3p and negatively regulated their expression. Finally, the TUG1 activated JNK and p38 MAPK pathways by sponging miR-493-3p/miR-410-3p.

Conclusion

TUG1 motivated the development of CIRI by sponging miR-493-3p/miR-410-3p to activate JNK and p38 pathways. The novel role of TUG1 in CIRI may contribute to the advancement of CIRI treatment.

LncRNA TP73-AS1 promotes oxidized low-density lipoprotein-induced apoptosis of endothelial cells in atherosclerosis by targeting the miR-654-3p/AKT3 axis

Background

Although lncRNA TP73-AS1 has been shown to play important roles in various human diseases, its function in atherosclerosis (AS) remains unclear.

Methods

Human aortic endothelial cells (HAECs) were treated with 50 μg/ml oxidized low-density lipoprotein (ox-LDL) to establish an atherosclerotic cell model. The expression of TP73-AS1, miR-654-3p and AKT3 was detected by qRT-PCR. Cell functions were evaluated CCK-8 assay and flow cytometry. The protein levels of apoptosis-related proteins were evaluated by western blot. The binding relationship among TP73-AS1, miR-654-3p and AKT3 was determined by bioinformatics analysis and luciferase reporter assay.

Results

TP73-AS1 was upregulated and miR-654-3p was downregulated in ox-LDL treated HAECs. TP73-AS1 silencing and miR-654-3p mimics decreased the viability and inhibited apoptosis of ox-LDL treated HAECs, decreased the expression levels of c-caspase-9, c-caspase-3 and Bax, and increased Bcl-2 expression. In addition, miR-654-3p inhibitor significantly reversed the inhibitory effects of si-TP73-AS1 on cell viability and apoptosis. TP73-AS1 could positively regulate AKT3 through directly sponging miR-654-3p.

Conclusion

TP73-AS1 promoted apoptosis of ox-LDL stimulated endothelial cells by targeting the miR-654-3p/AKT3 axis, suggesting that TP73-AS1 might be a potential target for AS treatment.

CircMYBL2 regulates the resistance of cervical cancer cells to paclitaxel via miR-665-dependent regulation of EGFR

Circular RNAs are considered to be associated with cancer resistance. This study aims to investigate the function and mechanism of circMYBL2 in paclitaxel (PTX) resistance of cervical cancer (CC). The expression of circMYBL2, miR-665 and epidermal growth factor receptor (EGFR) was investigated using quantitative real-time polymerase chain reaction assay. Cell viability, cell colony number, cell proliferation, apoptosis and lactate dehydrogenase (LDH) were detected by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, colony formation, 5-ethynyl-2'-deoxyuridine incorporation, flow cytometry and LDH release assays, respectively. The interaction between miR-665 and circMYBL2 or EGFR was confirmed by dual-luciferase reporter assay. The protein expression levels were quantified by western blot or immunohistochemistry assay. Mice xenograft models were constructed to investigate the effect of circMYBL2 on CC tumor growth. CircMYBL2 was upregulated in CC tissues and cells, especially in PTX-resistant CC tissues and cells, and it was a stable circRNA mainly distributed in the cytoplasm. CircMYBL2 could enhance the PTX resistance of CC cells in vitro and promote CC tumor growth in vivo. Mechanistically, circMYBL2 could inhibit the PTX sensitivity and promote cell malignant behaviors in PTX-sensitive and PTX-resistant CC cells via upregulating EGFR mediated by miR-665. CircMYBL2 played a positive role in the PTX resistance and malignant activities of PTX-sensitive and PTX-resistant CC cells by regulating the miR-665/EGFR network, providing a novel therapeutic strategy for the treatment of CC patients resistant to PTX.

MicroRNA-665 regulates the proliferation, apoptosis and adhesion of gastric cancer cells by binding to cadherin 3

Numerous studies have reported that abnormal cadherin 3 (CDH3) and microRNA (miRNA/miR)-665 expression can induce the progression of gastric cancer (GC). However, the mechanism of interaction between miR-665 and CDH3 in GC requires further investigation. The present study aimed to investigate the influence of miR-665 and CDH3 in GC development. The effect of miR-665 and CDH3 on GC tissues and cell lines was examined using reverse transcription-quantitative PCR. Subsequently, CDH3 protein expression in GC cell lines was detected using western blotting. To confirm the association between miR-665 and CDH3, a dual-luciferase reporter assay system was employed. Cell proliferation and adhesion were analyzed using BrdU ELISA, MTT and cell adhesion assays. Finally, caspase-3 activity assay kit and FITC apoptosis detection kit were used for the determination of apoptosis of GC cells. The current findings confirmed the upregulation of CDH3 expression in GC cell lines and tissues. Experimental results indicated that CDH3 overexpression increased cell proliferation and adhesion, but decreased the apoptosis level of the cells. Similarly, the miR-665 inhibitor enhanced cell proliferation and adhesion, but inhibited apoptosis of GC cells. Additionally, it was observed that CDH3 was a direct target of miR-665 in GC cells and that miR-665 inhibited CDH3 expression, thereby repressing the progression of GC. In conclusion, the present study suggested that by targeting CDH3, miR-665 suppressed the progression of GC. These findings may provide a significant theoretical basis for future GC clinical therapy.

Downregulation of lncRNA HCP5 has inhibitory effects on gastric cancer cells by regulating DDX21 expression

LncRNA HCP5 has been confirmed to play crucial roles in many types of cancers. However, the role of lncRNA HCP5 in regulating the occurrence and development of gastric cancer (GC) remains unknown. In the current study, we aimed to investigate the precise effects of lncRNA HCP5 on cell proliferation, migration and invasion and molecular mechanisms in gastric cancer. Using RT-qPCR analysis, we found that lncRNA HCP5 was differentially expressed in GC cell lines. CCK-8, wound healing and transwell assay indicated that the proliferation, migration and invasion of gastric cancer cells were inhibited by downregulation of lncRNA HCP5 and lncRNA HCP5 overexpression exhibited the opposite effects in gastric cancer cells. Mechanistically, RNA binding protein immunoprecipitation and dual luciferase reporter assay confirmed the interaction between lncRNA HCP5 and DDX21. The effects of lncRNA HCP5 overexpression the proliferation, migration and invasion of GC cells were partly rescued by DDX21 silencing. Taken together, downregulation of lncRNA HCP5 exerted inhibitory effects on GC cell proliferation, migration and invasion through modulation of DDX21 expression, demonstrating the function of lncRNA HCP5 and DDX21 in GC progression.

LINC00565 promotes the progression of colorectal cancer by upregulating EZH2

The present study aimed to illustrate the role of LINC00565 in aggravating colorectal cancer (CRC) by targeting enhancer of zeste homolog 2 (EZH2). The relative levels of LINC00565 and EZH2 in CRC tissues, based on their Tumor-Node-Metastasis stage and tumor size, were detected by reverse transcription-quantitative polymerase chain reaction. The diagnostic value of LINC00565 in CRC was assessed by depicting receiver operating characteristic curves. Pearson's correlation test was applied to analyze the expression correlation between LINC00565 and EZH2 in CRC tissues. The transfection efficacy of three LINC00565 small interfering RNAs was examined in CRC HCT116 and SW480 cell lines. After knockdown of LINC00565, the proliferative and migratory abilities of CRC cells were detected by Cell Counting Kit-8 and Transwell assays, respectively. The subcellular distribution of LINC00565 was analyzed, and the interaction between LINC00565 and EZH2 was determined by RNA immunoprecipitation. Finally, co-regulation of LINC00565 and EZH2 on CRC cell functions was explored by performing rescue experiments. Results showed that LINC00565 was upregulated in CRC tissues, especially in patients with stage III+IV and in those with large tumor sizes, suggesting its diagnostic value in CRC. EZH2 was also upregulated in CRC tissues, showing a positive correlation with LINC00565. LINC00565 was mainly expressed in the cytoplasm and was found to bind with EZH2. Validation was performed by overexpressing EZH2, which abolished the role of silenced LINC00565 in regulating proliferative and migratory abilities in CRC. Therefore, the upregulation of LINC00565 in CRC tissues was found to stimulate the aggravation of CRC by upregulating EZH2.

Long non-coding RNA FALEC promotes colorectal cancer progression via regulating miR-2116-3p-targeted PIWIL1

BACKGROUND

Colorectal cancer (CRC) is one of the most common digestive malignant tumors globally. Focally amplified lncRNA on chromosome 1 (FALEC) is a novel lncRNA that has been reported to be involved in many biological processes during carcinogenesis. However, its role in CRC remains poorly understood.

METHODS

Gene expression at mRNA or protein level was measured by qRT-PCR or western blot, respectively. In vitro experiments including EdU, colony formation, flow cytometry, wound-healing and transwell assays, as well as in vivo xenograft experiment, were utilized to determine the functional role of FALEC in CRC. Relevant mechanical assays were performed to investigate the underlying molecular mechanism.

RESULTS

FALEC was aberrantly up-regulated in CRC. FALEC knockdown could impair CRC cell proliferation, migration and invasion, whereas facilitate cell apoptosis. MiR-2116-3p was revealed to be sponged by FALEC. PIWIL1 was identified as the target of miR-2116-3p. Mechanically, FALEC restored the expression of PIWIL1 via absorbing miR-2116-3p. MiR-2116-3p inhibition and PIWIL1 enrichment could counteract the anti-tumor impact induced by silenced FALEC on the oncogenic behaviors of CRC cells.

CONCLUSION

Our study revealed that FALEC promoted CRC progression via restoring the expression of miR-2116-3p-targeted PIWIL1, suggesting the potential application of targeting FALEC in the treatment of CRC.

miR-635 targets KIFC1 to inhibit the progression of gastric cancer

Accumulating studies have shown that the dysregulation of microRNAs is related to the carcinogenesis and development of gastric cancer (GC), and the role of miR-635 in GC remains largely unknown. miR-635 and Kinesin Family Member C1 (KIFC1) mRNA expression in GC tissues and paracancerous tissues and cells were detected by quantitative real-time PCR. KIFC1 protein expression in GC tissues and paracancerous normal tissues and cells was detected by immunohistochemistry and western blot. Cell proliferation was monitored by Cell Counting Kit-8 assay and 5-bromo-2′-deoxyuridine assay. Transwell assay was employed to detect the migration and invasion of GC cells. The dual-luciferase reporter gene assay was adopted to detect the targeting relationship between miR-635 and KIFC1. Compared with paracancerous tissues, miR-635 expression was remarkably decreased in GC tissues; conversely, KIFC1 expression was significantly increased. Compared with human normal gastric epithelial cell GSE-1, miR-635 expression was markedly decreased in GC cell lines. Meanwhile, KIFC1 expression was significantly increased, and the Kaplan-Meier Plotter database showed that its high expression was remarkably associated with poor prognosis. Additionally, miR-635 can negatively regulate KIFC1. miR-635 can target KIFC1 to inhibit proliferation, migration and invasion of GC cells. Collectively, miR-635 is lowly expressed in GC, and it inhibits proliferation, migration and invasion of GC cells via regulating KIFC1.

LncRNA TGFB2-AS1 regulates lung adenocarcinoma progression via act as a sponge for miR-340-5p to target EDNRB expression

Long non-coding RNA TGFB2-antisense RNA1 (TGFB2-AS1) has been reported could regulate tumorigenesis. However, the roles of TGFB2-AS1 in lung adenocarcinoma (LUAD) remain largely unknown. In this work, we aimed to explore the expression levels of TGFB2-AS1 and mechanisms in regulating LUAD progression. Expression level of TGFB2-AS1 in LUAD tissues and normal tissues was analyzed at StarBase. Moreover, its expression in LUAD cells and normal cell was analyzed with quantitative real-time polymerase chain reaction method. Gain- and loss-of-function studies were conducted to analyze the biological roles of TGFB2-AS1 in LUAD. Results indicated TGFB2-AS1 was evidently downregulated in LUAD tissues and cells. Moreover, as analyzed by cell counting kit-8 assay, wound-healing and transwell invasion assays, results revealed TGFB2-AS1 overexpression could suppress proliferation, migration and invasion abilities of LUAD cells in vitro and tumor growth in vivo. In addition, LncBase V2.0 and TargetScan prediction tools showed TGFB2-AS1 and endothelin receptor type B (EDNRB) shares binding site in microRNA-340-5p (miR-340-5p). Furthermore, luciferase activity reporter assay and RT-qPCR assay validated these prediction results. Furthermore, we showed TGFB2-AS1 functions as sponge for miR-340-5p to regulate EDNRB expression. Collectively, our results indicated TGFB2-AS1/miR-340-5p/EDNRB axis plays crucial roles in regulating LUAD progression, indicating TGFB2-AS1 may be a novel therapeutic target for LUAD.

LINC00565 Enhances Proliferative Ability in Endometrial Carcinoma by Downregulating KLF9

Objective

To detect LINC00565 expression level in endometrial carcinoma (EC) samples and cell lines, and the correlations between LINC00565 and clinical features of EC patients. After intervening LINC00565, the underlying mechanism about proliferative ability in EC cell lines is observed.

Methods

Relative levels of LINC00565 and KLF9 in 52 paired EC and paracancerous tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between relative level of LINC00565 or KLF9 and clinical features of EC patients was analyzed. After knockdown of LINC00565 and KLF9, potential regulations of them on biological functions of EC were examined by Cell Counting Kit (CCK-8), colony formation assay and in vivo xenograft model in nude mice, respectively. At last, dual-luciferase reporter assay and rescue experiments were conducted to illustrate the mechanisms of LINC00565 and KLF9 in mediating the development of EC.

Results

LINC00565 was upregulated in EC tissues. Chi-square analysis showed that a high level of LINC00565 predicted large tumor size, advanced pathological staging and poor prognosis in EC. Silence of LINC00565 decreased proliferative ability in EC cells and tumor growth in nude mice bearing EC. KLF9 was the target gene of LINC00565. The negative interaction between LINC00565 and KLF9 was responsible for stimulating the malignant development of EC. Knockdown of KLF9 could abolish the regulatory effects of silenced LINC00565 on proliferative ability and tumorigenesis in EC.

Conclusion

LINC00565 is upregulated in EC tissues and closely linked to tumor size, pathological staging and poor prognosis in EC patients. LINC00565 stimulates proliferative ability in EC by downregulating KLF9.

LncRNA CRNDE and lncRNA SNHG7 are Promising Biomarkers for Prognosis in Synchronous Colorectal Liver Metastasis Following Hepatectomy

Purpose

Synchronous colorectal liver metastasis (SCLM) had limited availability of tools to predict survival and tumor recurrence. LncRNA CRNDE and lncRNA SNHG7 have been proven to be closely related to cancer progression. However, the predictive value of lncRNA CRNDE and lncRNA SNHG7 in cancer prognosis is still unclear. The purpose of this study was to investigate whether lncRNA CRNDE and lncRNA SNHG7 could be used as promising biomarkers for prognosis prediction of SCLM patients who underwent hepatectomy.

Methods

The expression profile of lncRNA CRNDE and lncRNA SNHG7 in serum of SCLM patients was examined by qRT-PCR. The relationship between lncRNA expression and clinicopathological characteristics was analyzed. The Cox proportional-hazards regression model and Kaplan-Meier analysis were performed to analyze the association between lncRNA expression and overall survival (OS) and tumor recurrence of SCLM patients.

Results

Levels of lncRNA CRNDE and lncRNA SNHG7 in patients who underwent recurrence or death were significantly higher than that of patients with recurrence-free or survival (P<0.01). Both lncRNA CRNDE high level and lncRNA SNHG7 high level showed a significant correlation with differentiation of primary tumor, invasion depth of primary focus, lymph node metastases, number of liver metastases, and liver metastasis grade. High levels of lncRNA CRNDE or lncRNA SNHG7 predicted shorter recurrence time, shorter OS time, higher recurrence rate and lower OS rate. Furthermore, lncRNA CRNDE and lncRNA SNHG7 were independent risk factors for high recurrence and poor OS in SCLM underwent hepatectomy.

Conclusion

Taken together, lncRNA CRNDE and lncRNA SNHG7 could be promising biomarkers for prediction of OS and tumor recurrence in SCLM underwent hepatectomy.