LncRNA-LOC101928316 contributes to gastric cancer progression through regulating PI3K-Akt-mTOR signaling pathway

Differential expression and clinical significance of long non-coding RNAs in the development and progression of lung adenocarcinoma

With the development of gene testing technology, we have found many different genes, and lncRNA is one of them. LncRNAs refer to a non-protein coding RNA molecule with a length of more than 200bp, which is one of the focuses of research on human malignant diseases such as LUAD. LncRNAs act as an oncogene or inhibitor to regulate the occurrence and progression of tumors. The differential expression of LncRNAs promotes or inhibits the progression of lung adenocarcinoma by affecting cell proliferation, metastasis, invasion, and apoptosis, thus affecting the prognosis and survival rate of patients. Therefore, LncRNAs can be used as a potential target for diagnosis and treatment of cancer. The early diagnosis of the disease was made through the detection of tumor markers. Because lung adenocarcinoma is not easy to diagnose in the early stage and tumor markers are easy to ignore, LncRNAs play an important role in the diagnosis and treatment of lung adenocarcinoma. The main purpose of this article is to summarize the known effects of LncRNAs on lung adenocarcinoma, the effect of differential expression of LncRNAs on the progression of lung adenocarcinoma, and related signal transduction pathways. And to provide a new idea for the future research of lung adenocarcinoma-related LncRNAs.

Targeting PI3K/AKT/mTOR and MAPK Signaling Pathways in Gastric Cancer

Gastric cancer (GC) is the fourth leading cause of death worldwide, with more than 1 million cases diagnosed every year. Helicobacter pylori represents the main risk factor, being responsible for 78% of the cases. Increased amounts of salt, pickled food, red meat, alcohol, smoked food, and refined sugars negatively affect the stomach wall, contributing to GC development. Several gene mutations, including PIK3CA, TP53, ARID1A, CDH1, Ras, Raf, and ERBB3 are encountered in GC pathogenesis, leading to phosphatidylinositol 3-kinase (PI3K) protein kinase B (AKT)/mammalian target of rapamycin (mTOR)-PI3K/AKT/mTOR-and mitogen-activated protein kinase (MAPK) signaling pathway activation and promoting tumoral activity. Helicobacter pylori, growth factors, cytokines, hormones, and oxidative stress also activate both pathways, enhancing GC development. In clinical trials, promising results have come from monoclonal antibodies such as trastuzumab and ramucirumab. Dual inhibitors targeting the PI3K/AKT/mTOR and MAPK signaling pathways were used in vitro studies, also with promising results. The main aim of this review is to present GC incidence and risk factors and the dysregulations of the two protein kinase complexes together with their specific inhibitors.

Decoding the regulatory landscape of lncRNAs as potential diagnostic and prognostic biomarkers for gastric and colorectal cancers

Colorectal cancer (CRC) and gastric cancer (GC) are major contributors to cancer-related mortality worldwide. Despite advancements in understanding molecular mechanisms and improved drug treatments, the overall survival rate for patients remains unsatisfactory. Metastasis and drug resistance are major challenges contributing to the high mortality rate in both CRC and GC. Recent research has shed light on the role of long noncoding RNAs (lncRNAs) in the development and progression of these cancers. LncRNAs regulate gene expression through various mechanisms, including epigenetic modifications and interactions with microRNAs (miRNAs) and proteins. They can serve as miRNA precursors or pseudogenes, modulating gene expression at transcriptional and post-transcriptional levels. Additionally, circulating lncRNAs have emerged as non-invasive biomarkers for the diagnosis, prognosis, and prediction of drug therapy response in CRC and GC. This review explores the intricate relationship between lncRNAs and CRC/GC, encompassing their roles in cancer development, progression, and chemoresistance. Furthermore, it discusses the potential of lncRNAs as therapeutic targets in these malignancies. The interplay between lncRNAs, miRNAs, and tumor microenvironment is also highlighted, emphasizing their impact on the complexity of cancer biology. Understanding the regulatory landscape and molecular mechanisms governed by lncRNAs in CRC and GC is crucial for the development of effective diagnostic and prognostic biomarkers, as well as novel therapeutic strategies. This review provides a comprehensive overview of the current knowledge and paves the way for further exploration of lncRNAs as key players in the management of CRC and GC.

Long Non-Coding RNAs (lncRNAs) as Regulators of the PI3K/AKT/mTOR Pathway in Gastric Carcinoma

Gastric cancer (GC) represents ~10% of the global cancer-related deaths, increasingly affecting the younger population in active stages of life. The high mortality of GC is due to late diagnosis, the presence of metastasis and drug resistance development. Additionally, current clinical markers do not guide the patient management adequately, thereby new and more reliable biomarkers and therapeutic targets are still needed for this disease. RNA-seq technology has allowed the discovery of new types of RNA transcripts including long non-coding RNAs (lncRNAs), which are able to regulate the gene/protein expression of many signaling pathways (e.g., the PI3K/AKT/mTOR pathway) in cancer cells by diverse molecular mechanisms. In addition, these lncRNAs might also be proposed as promising diagnostic or prognostic biomarkers or as potential therapeutic targets in GC. This review describes important topics about some lncRNAs that have been described as regulators of the PI3K/AKT/mTOR signaling pathway, and hence, their potential oncogenic role in the development of this malignancy.

Loss of cancer-associated fibroblast-derived exosomal DACT3-AS1 promotes malignant transformation and ferroptosis-mediated oxaliplatin resistance in gastric cancer

AIMS

Long non-coding RNAs (lncRNAs), as one of the components of exosomes derived from cancer-associated fibroblasts (CAFs), exhibit a crucial role in the pathogenesis and chemoresistance of gastric cancer (GC). Herein, we investigated the role and mechanism of a novel lncRNA disheveled binding antagonist of beta catenin3 antisense1 (DACT3-AS1) and its involvement in GC.

METHODS

DACT3-AS1 was identified by RNA-sequencing and verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The functional role of DACT3-AS1 in GC was evaluated using in vitro and in vivo experiments including Transwell assay, 5-Ethynyl-2'-deoxyuridine (EdU) assay, immunoblotting, and xenograft tumor mouse model. Dual-luciferase reporter assay was performed to assess the association between genes.

RESULTS

DACT3-AS1 was downregulated and involved in poor prognosis of patients with GC. The results from both in vitro and in vivo experiments showed that DACT3-AS1 suppressed cell proliferation, migration, and invasion through targeting miR-181a-5p/sirtuin 1 (SIRT1) axis. Additionally, DACT3-AS1 was transmitted from CAFs to GC cells mainly via exosomes. Exosomal DACT3-AS1 alleviated xenograft tumor growth. DACT3-AS1 conferred sensitivity of cancer cells to oxaliplatin through SIRT1-mediated ferroptosis both in vitro and in vivo.

CONCLUSIONS

CAFs-derived exosomal DACT3-AS1 is a suppressive regulator in malignant transformation and oxaliplatin resistance. DACT3-AS1 could be used for diagnosis and treatment of GC.

Hsa_circ_0044301 Regulates Gastric Cancer Cell’s Proliferation, Migration, and Invasion by Modulating the Hsa-miR-188-5p/DAXX Axis and MAPK Pathway

Simple Summary

This study aimed to investigate whether circRNA could be potential prognosis or therapeutic target. And we found the upregulated hsa_circ_0044301 was positively correlated with the 5-year survival rate of patients, which also could influence the proliferation, migration and invasion of gastric cancer cells in vitro and in vivo. Mechanically, it could act as the sponge of hsa-miR-188-5p and regulate the expression and function of targeted gene DAXX. In addition, this circRNA could also modulate the effect of GDC-0994 on ERK1/2 or 5-FU in cells. These findings have made a significant contribution to the study of circRNA in the treatment field of gastric cancer. Meanwhile this is the first detailed investigation of hsa_circ_0044301 in gastric cancer, and the circRNA has the value of further animal and clinical translation.

Abstract

Background: Despite advances in diagnostic and therapeutic technologies, the prognosis of patients with gastric cancer (GC) remains poor, necessitating further search for more effective therapeutic targets and markers for prognosis prediction. Circular RNA (circRNA) plays a role in various diseases, including GC. Methods: CircRNA expression in GC tissues was detected by circRNA microarray and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The correlation between circRNA-0044301 and patient survival was analyzed by log-rank test and Cox regression analysis. Next, in vitro characterization and functional analysis of circRNA-0044301 was done by various assays using RNase R, actinomycin D, and RNA fluorescence in situ hybridization, as well as investigations into its use as a drug to treat tumors in a subcutaneous tumorigenesis model. RNA immunoprecipitation and dual-luciferase reporter assays were used to identify circRNA-0044301-related miRNA (miRNA-188-5p), key proteins of the related pathway (ERK1/2), and the downstream target DAXX. Finally, we investigated the relationship between circRNA-0044301 and ravoxertinib (GDC-0994) and 5-fluorouracil (5-FU) using qRT-PCR, Western blotting, and CCK8 assays. Results: CircRNA-0044301 was upregulated in tissues and cancer cells compared to its levels in controls, related to patient prognosis, and its specific siRNA-vivo could slow tumor growth. On the mechanism, it acted as a sponge of miRNA-188-5p, could regulate the downstream target DAXX, and modulated the effect of GDC-0994 on ERK1/2 and 5-FU in cells. Conclusions: CircRNA-0044301/miRNA-188-5p/DAXX (ERK1/2) may be a key axis in GC progression, and circRNA-0044301 has immense potential to be a therapeutic target for GC.

LncRNA DLEU2 silencing impedes the migration, invasion and EMT in gastric cancer cell by suppressing PI3K/AKT signaling pathway

Context: The high expression of long non-coding RNA deleted in lymphocytic leukaemia 2 (lncRNA DLEU2) has been confirmed in gastric cancer (GC).Objective: However, the detailed mechanism concerning its involvement in GC remained unclear, which we aimed to explore in this study.Materials and methods: LncRNA DLEU2 expression in GC was estimated by bioinformatic analysis, and the relationship between the expression of DLEU2 and the clinicopathological characteristics of patients with GC was performed. qRT-PCR was employed to detect the expression of lncRNA DLEU2 and confirm the transfection efficiency following the knockdown or overexpression of DLEU2. Functional assays, including CCK-8, flow cytometry, scratching test and Transwell assays, were used to determine the role of DLEU2 in tumor phenotypes. The effects of DLEU2 on the PI3K/Akt pathway were detected by western blot. For elucidating the functions of DLEU2/PI3K/Akt axis in GC, we inhibited the PI3K/Akt pathway in rescue experiments, and evaluated the expression levels of epithelial-mesenchymal transition (EMT)-related proteins by western blot.Results: The expression of DLEU2 was aberrantly up-regulated in GC tissues and cells, which was correlated with the degree of tumor differentiation, cancer antigen 19-9 (CA19-9) and Lauren histologic classification of patients with GC. Silencing of DLEU2 induced apoptosis, attenuated viability, migration and invasion as well as inhibited the PI3K/Akt signaling pathway in GC cells. Mechanistically, the DLEU2/PI3K/Akt axis promoted the progression of GC and the EMT by down-regulating the expression of E-Cadherin and up-regulating those of N-Cadherin and Vimentin.Discussion and conclusions: LncRNA DLEU2 promoted the migration, invasion and EMT in GC by activating the PI3K/Akt pathway.

Long non-coding RNAs: Biogenesis, functions, and clinical significance in gastric cancer

Gastric cancer (GC) is one of the most prevalent malignant tumor types and the third leading cause of cancer-related death worldwide. Its morbidity and mortality are very high due to a lack of understanding about its pathogenesis and the slow development of novel therapeutic strategies. Long non-coding RNAs (lncRNAs) are a class of non-coding RNAs with a length of more than 200 nt. They play crucial roles in a wide spectrum of physiological and pathological processes by regulating the expression of genes involved in proliferation, differentiation, apoptosis, cell cycle, invasion, metastasis, DNA damage, and carcinogenesis. The aberrant expression of lncRNAs has been found in various cancer types. A growing amount of evidence demonstrates that lncRNAs are involved in many aspects of GC pathogenesis, including its occurrence, metastasis, and recurrence, indicating their potential role as novel biomarkers in the diagnosis, prognosis, and therapeutic targets of GC. This review systematically summarizes the biogenesis, biological properties, and functions of lncRNAs and highlights their critical role and clinical significance in GC. This information may contribute to the development of better diagnostics and treatments for GC.

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.

Non-Coding RNAs in Gastric Cancer: From Malignant Hallmarks to Clinical Applications

Gastric cancer (GC) is one of the most lethal malignancies worldwide. However, the molecular mechanisms underlying gastric carcinogenesis remain largely unknown. Over the past decades, advances in RNA-sequencing techniques have greatly facilitated the identification of various non-coding RNAs (ncRNAs) in cancer cells, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). Accumulating evidence has revealed that ncRNAs are essential regulators in GC occurrence and development. However, ncRNAs represent an emerging field of cancer research, and their complex functionality remains to be clarified. Considering the lack of viable biomarkers and therapeutic targets in GC, further studies should focus on elucidating the intricate relationships between ncRNAs and GC, which can be translated into clinical practice. In this review, we summarize recent research progress on how ncRNAs modulate the malignant hallmarks of GC, especially in tumor immune escape, drug resistance, and stemness. We also discuss the promising applications of ncRNAs as diagnostic biomarkers and therapeutic targets in GC, aiming to validate their practical value for clinical treatment.

The Role of LncRNAs in Translation

Long non-coding RNAs (lncRNAs), a group of non-protein coding RNAs with lengths of more than 200 nucleotides, exert their effects by binding to DNA, mRNA, microRNA, and proteins and regulate gene expression at the transcriptional, post-transcriptional, translational, and post-translational levels. Depending on cellular location, lncRNAs are involved in a wide range of cellular functions, including chromatin modification, transcriptional activation, transcriptional interference, scaffolding and regulation of translational machinery. This review highlights recent studies on lncRNAs in the regulation of protein translation by modulating the translational factors (i.e, eIF4E, eIF4G, eIF4A, 4E-BP1, eEF5A) and signaling pathways involved in this process as wells as their potential roles as tumor suppressors or tumor promoters.

The emerging role of non-coding RNAs in the regulation of PI3K/AKT pathway in the carcinogenesis process

The PI3K/AKT pathway is an intracellular signaling pathway with an indispensable impact on cell cycle control. This pathway is functionally related with cell proliferation, cell survival, metabolism, and quiescence. The crucial role of this pathway in the development of cancer has offered this pathway as a target of novel anti-cancer treatments. Recent researches have demonstrated the role of microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in controlling the PI3K/AKT pathway. Some miRNAs such as miR-155-5p, miR-328-3p, miR-125b-5p, miR-126, miR-331-3p and miR-16 inactivate this pathway, while miR-182, miR-106a, miR-193, miR-214, miR-106b, miR-93, miR-21 and miR-103/107 enhance activity of this pathway. Expression levels of PI3K/AKT-associated miRNAs could be used to envisage the survival of cancer patients. Numerous lncRNAs such as GAS5, FER1L4, LINC00628, PICART1, LOC101928316, ADAMTS9-AS2, SLC25A5-AS1, MEG3, AB073614 and SNHG6 interplay with this pathway. Identification of the impact of miRNAs and lncRNAs in the control of the activity of PI3K/AKT pathway would enhance the efficacy of targeted therapies against this pathway. Moreover, each of the mentioned miRNAs and lncRNAs could be used as a putative therapeutic candidate for the interfering with the carcinogenesis. In the current study, we review the role of miRNAs and lncRNAs in controlling the PI3K/AKT pathway and their contribution to carcinogenesis.

Non-coding RNAs underlying chemoresistance in gastric cancer

BACKGROUND

Gastric cancer (GC) is a major health issue in the Western world. Current clinical imperatives for this disease include the identification of more effective biomarkers to detect GC at early stages and enhance the prevention and treatment of metastatic and chemoresistant GC. The advent of non-coding RNAs (ncRNAs), particularly microRNAs (miRNAs) and long-non coding RNAs (lncRNAs), has led to a better understanding of the mechanisms by which GC cells acquire features of therapy resistance. ncRNAs play critical roles in normal physiology, but their dysregulation has been detected in a variety of cancers, including GC. A subset of ncRNAs is GC-specific, implying their potential application as biomarkers and/or therapeutic targets. Hence, evaluating the specific functions of ncRNAs will help to expand novel treatment options for GC.

CONCLUSIONS

In this review, we summarize some of the well-known ncRNAs that play a role in the development and progression of GC. We also review the application of such ncRNAs in clinical diagnostics and trials as potential biomarkers. Obviously, a deeper understanding of the biology and function of ncRNAs underlying chemoresistance can broaden horizons toward the development of personalized therapy against GC.

LncRNA NEAT1 promotes gastric cancer progression via miR-1294/AKT1 axis

Long non-coding RNAs (lncRNAs) were reported to promote the development of gastric cancer (GC). Nuclear-enriched abundant transcript 1 (NEAT1) played a great role in diverse cancers, but the mechanism of NEAT1 in GC remains indistinct. NEAT1 and AKT1 were distinctly up-regulated and miR-1294 was down-regulated in GC tissues and cells. Cell proliferation and metastasis were refrained but apoptosis was promoted in GC cells after knockdown of NEAT1. NEAT1 negatively regulated miR-1294 expression, and the miR-1294 inhibitor reverted the si-NEAT1-induced effect on GC cells. NEAT1 modulated AKT1 expression through miR-1294, and the si-NEAT1-induced effect was relieved by AKT1. NEAT1 affected phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway via regulating miR-1294 and AKT1. NEAT1 could modulate cell proliferation, apoptosis, and metastasis in GC cells by regulating the PI3K/AKT/mTOR signaling pathway via the miR-1294/AKT1 axis, showing the great potential for NEAT1 as a valid biomarker in the progression and treatment of GC.

PI3K/AKT/mTOR signaling in gastric cancer: Epigenetics and beyond

PI3K/AKT/mTOR pathway is one of the most important signaling pathways involved in normal cellular processes. Its aberrant activation modulates autophagy, epithelial-mesenchymal transition, apoptosis, chemoresistance, and metastasis in many human cancers. Emerging evidence demonstrates that some infections as well as epigenetic regulatory mechanisms can control PI3K/AKT/mTOR signaling pathway. In this review, we focused on the role of this pathway in gastric cancer development, prognosis, and metastasis, with an emphasis on epigenetic alterations including DNA methylation, histone modifications, and post-transcriptional modulations through non-coding RNAs fluctuations as well as H. pylori and Epstein-Barr virus infections. Finally, we reviewed different molecular targets and therapeutic agents in clinical trials as a potential strategy for gastric cancer treatment through the PI3K/AKT/mTOR pathway.

LBX2-AS1/miR-219a-2-3p/FUS/LBX2 positive feedback loop contributes to the proliferation of gastric cancer

BACKGROUND

Long non-coding RNAs (lncRNAs) are increasingly investigated in numerous carcinomas containing gastric cancer (GC). The aim of our research is to inquire about the expression profile and role of LBX2-AS1 in GC.

METHODS

The expressions of LBX2-AS1, miR-219a-2-3p, FUS and LBX2 were measured by qRT-PCR. Western blot evaluated FUS and LBX2 protein levels. Cell proliferation and apoptosis were, respectively, evaluated by CCK-8, colony formation, EdU, flow cytometry and TUNEL assays. FISH and subcellular fractionation assays examined the position of LBX2-AS1. The binding between genes were certified by RIP, RNA pull-down, ChIP and luciferase reporter assays. Pearson correlation analysis analyzed the association of genes. Kaplan-Meier method detected the relationship of LBX2-AS1 expression with overall survival.

RESULTS

The up-regulation of LBX2-AS1 in GC tissues and cells was verified. Function assays proved that LBX2-AS1 down-regulation restricted the proliferation ability. Then, we unveiled the LBX2-AS1/miR-219a-2-3p/FUS axis. Additionally, LBX2-AS1 positively regulated LBX2 mRNA stability via FUS. LBX2 transcriptionally modulated LBX2-AS1. In the end, rescue and in vivo experiments validated the whole regulatory mechanism.

CONCLUSION

LBX2-AS1/miR-219a-2-3p/FUS/LBX2 positive feedback loop mainly affected the proliferation and apoptosis abilities of GC cells, offering novel therapeutic targets for the treatment of patients with GC.

Long non-coding RNA ARAP1-AS1 promotes tumorigenesis and metastasis through facilitating proto-oncogene c-Myc translation via dissociating PSF/PTB dimer in cervical cancer

Long non-coding RNA (lncRNA) is emerging as a pivotal regulator in tumorigenesis and aggressive progression. Here, we focused on an oncogenic lncRNA, ARAP1 antisense RNA 1 (ARAP1-AS1), which was notably upregulated in cervical cancer (CC) tissues, cell lines and serum. High ARAP1-AS1 expression was closely associated with larger tumor size, advanced FIGO stage as well as lymph node metastasis. Importantly, it was identified as an effective diagnostic and prognostic biomarker for CC. In vitro and in vivo assays showed that knockdown of ARAP1-AS1 inhibited, while overexpression of ARAP1-AS1 promoted CC cell growth and dissemination. Stepwise mechanistic dissection unveiled that ARAP1-AS1 could directly interact with PSF to release PTB, resulting in accelerating the internal ribosome entry site (IRES)-driven translation of proto-oncogene c-Myc, thereby facilitating CC development and progression. Moreover, c-Myc was able to transcriptionally activate ARAP1-AS1 by directly binding to the E-box motif located on ARAP1-AS1 promoter. Taken together, our findings clearly reveal the crucial role of ARAP1-AS1 in CC tumorigenesis and metastasis via regulation of c-Myc translation, targeting ARAP1-AS1 and its related regulatory loop implicates the therapeutic possibility for CC patients.

Long non-coding RNA ERICH3-AS1 is an unfavorable prognostic factor for gastric cancer

Long non-coding RNAs (lncRNAs) play important roles in gastric cancer (GC), but the mechanism is not fully clear. ERICH3-AS1 (ERICH3 antisense RNA1) is affiliated with the non-coding RNA class which has proven to be involved in the prognostic of GC, but the function of ERICH3-AS1 is still unclear. In this study, we aim to explore the potential function of ERICH3-AS1 in the development of GC and analyze the prognostic role of ERICH3-AS1 in GC. We found that the lncRNA ERICH3-AS1 was significantly up-regulated in GC tissues in the analysis of The Cancer Genome Atlas (TCGA) data; the Kaplan-Meier analysis showed that the higher the expression of ERICH3-AS1 was, the earlier the recurrence and the poorer the prognosis would be in patients. Cox univariate and multivariate analyses revealed that ERICH3-AS1 was a risk factor of disease-free survival (DFS) (p < 0.05) and overall survival (OS) (p < 0.05) of patients. Through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, it demonstrated that the ERBB pathways, the mitogen-activated protein kinase (MAPK) pathways, the MTOR pathways, p53 pathways and Wnt pathways were differentially enriched in ERICH3-AS1 high expression phenotype. Furthermore, the correlation analysis showed that ERICH3-AS1 had significant correlations with apoptosis-related proteins such as BCL2L10 and CASP14; cell cycle-associated proteins CDK14 and invasion and migration-associated proteins such as MMP20, MMP26 and MMP27. In summary, we identified that increased ERICH3-AS1 might be a potential biomarker for diagnosis and independent prognostic factor of GC. Moreover, ERICH3-AS1 might participate in the oncogenesis and development of tumors via cell cycle and apoptosis pathway mediated by ERBB, MAPK, MTOR, p53 and Wnt pathways.

The Down-Regulation of lncRNA PCAT18 Promotes the Progression of Gastric Cancer via MiR-107/PTEN/PI3K/AKT Signaling Pathway

Purpose

LncRNAs are important regulators in cancers. In this study, we investigated the role of lncRNA PCAT18 in gastric cancer (GC).

Patients and Methods

The level of PCAT18 in GC tissues and cells was determined by qRT-PCR. The cellular behaviors of GC cells with knockdown or overexpression of PCAT18 were respectively detected by CCK-8 assays, colony formation assays, flow cytometry and Western blot. A GC mice model was established by subcutaneous injection of MGC-803 and HGC-27 cells with the knockdown or overexpression of PCAT18. The tumor size and weight were measured, and IHC was performed to determine ki-67 level. Predicted by bioinformatics software and confirmed by dual-luciferase reporter assay, PCAT18 was involved in miR-107/PTEN axis, thus, the expression of and relationship among PCAT18, miR-107 and PTEN pathway were explored in clinical cases and GC cell lines. Rescue assay was performed in GC cells by co-transfection with miR-107 mimic or PCAT18. The PTEN/PI3K/AKT pathway was then detected by Western blot.

Results

PCAT18 was down-regulated in GC tissues and cells, and it had a significant diagnostic value for GC. The expression of PCAT18 was highly associated with tumor size, and PCAT18 was found to inhibit GC growth in vitro and in vivo. It was also found that PCAT18 was involved in PTEN/PI3K/AKT signaling pathway through targeting miR-107.

Conclusion

PCAT18 inhibits the progression of GC via miR-107/PTEN/PI3K/AKT signaling pathway. Additionally, PCAT18 is possibly a promising target for treatment of GC.

Ethanol extract of Ligustrum lucidum Ait. leaves suppressed hepatocellular carcinoma in vitro and in vivo

Background

The present study investigated the pharmacological activity and mechanism of ethanol extract of Ligustrum lucidum Ait. leaves (EEL) on HCC.

Methods

Cell viability was determined using cell counting kit-8 (CCK-8) assay. The effects of EEL on cellular biological activities were analyzed by flow cytometry (FCM), cell wound scratch assay and transwell assay. The expression levels of related mRNA and protein were determined by performing quantitative real-time PCR (qRT-PCR), Western blotting assay and immunocytochemistry. Methylation-specific PCR (MSP) was carried out to investigate the possible mechanism underlying the DNA methylation of PTEN.

Results

EEL showed cytotoxicity to both Bel-7402 and Huh-7 cell lines. We also found that EEL enhanced the apoptosis of Bel-7402 and Huh-7 cells by regulating the expressions of Bcl-2 associated X (Bax), B cell lymphoma 2 (Bcl-2) and Cytochrome-C and the activity of caspase-3 and therefore promoted cell cycle arrest. Moreover, EEL also suppressed cell migration and invasion. EEL increased the expression of tissue inhibitor of metalloproteinases 2 (TIMP2) but decreased the expressions of matrix metalloproteinase2 (MMP2) and MMP9. Furthermore, EEL inhibited the phosphorylation of PI3K/Akt pathway. MSP results showed that EEL promoted the demethylation of PTEN, suggesting that the inactivation of PI3K/Akt may be related to DNA de-methylation of PTEN. In addition, EEL inhibited the tumor growth of HCC in vivo.

Conclusions

EEL exerted anti-tumor effect on HCC in vitro and in vivo. EEL mediated by the inhibition of PI3K/Akt may be closely related to DNA de-methylation of PTEN. Thus, EEL could be used as a potential anti-cancer therapeutic agent of HCC.

LncRNA-LOC101928316 contributes to gastric cancer progression through regulating PI3K-Akt-mTOR signaling pathway

Long noncoding RNA (lncRNA) has played the important function in regulation of various biological processes and in diagnostic value has been widely appreciated. In the present study, we have found that LOC101928316 was significantly downregulated in gastric cancer (GC) tissues specimen, GC cell lines, and associated with the GC patients tumor, node, and metastasis (TNM) stage and degree of differentiation (P ＜ 0.05). LOC101928316 overexpression can significantly inhibit SGC‐7901 cell migration, invasion, and proliferation (P＜0.05). LOC101928316 molecular mechanism investigates suggested that LOC101928316 can regulate PI3K‐Akt‐mTOR signaling pathway and change the GC development progression in vivo and in vitro. In vivo experiment also revealed that LOC101928316‐Overexpression can inhibit the tumorigenicity of GC cells in tumor‐burdened experimental nude mice (P ＜ 0.05). LOC101928316 may function as anti‐oncogene and also plays an important role in GC tumorigenesis. Collectively, our data provided the key role of LOC101928316 in the tumorigenesis of GC. In addition, the present study elucidates LOC101928316 potential regulatory network, which may help us to lead a better knowing of the pathogenesis of GC and probe the lncRNA as a novel biomarker to diagnosis and therapy for this malignant tumor.