Long non-coding RNA LINC00628 functions as a gastric cancer suppressor via long-range modulating the expression of cell cycle related genes

Cell Cycle-Related lncRNAs as Innovative Targets to Advance Cancer Management

Long non-coding RNAs (lncRNAs) are non-coding RNAs (ncRNAs) longer than 200nt. They have complex biological functions and take part in multiple fundamental biological processes, such as cell proliferation, differentiation, survival and apoptosis. Recent studies suggest that lncRNAs modulate critical regulatory proteins involved in cancer cell cycle, such as cyclin, cell cycle protein-dependent kinases (CDK) and cell cycle protein-dependent kinase inhibitors (CKI) through different mechanisms. To clarify the role of lncRNAs in the regulation of cell cycle will provide new ideas for design of antitumor therapies which intervene with the cell cycle progression. In this paper, we review the recent studies about the controlling of lncRNAs on cell cycle related proteins such as cyclin, CDK and CKI in different cancers. We further outline the different mechanisms involved in this regulation and describe the emerging role of cell cycle-related lncRNAs in cancer diagnosis and therapy.

Chromatin and noncoding RNA-mediated mechanisms of gastric tumorigenesis

Gastric cancer (GC) is one of the most common and deadly cancers in the world. It is a multifactorial disease highly influenced by environmental factors, which include radiation, smoking, diet, and infectious pathogens. Accumulating evidence suggests that epigenetic regulators are frequently altered in GC, playing critical roles in gastric tumorigenesis. Epigenetic regulation involves DNA methylation, histone modification, and noncoding RNAs. While it is known that environmental factors cause widespread alterations in DNA methylation, promoting carcinogenesis, the chromatin- and noncoding RNA-mediated mechanisms of gastric tumorigenesis are still poorly understood. In this review, we focus on discussing recent discoveries addressing the roles of histone modifiers and noncoding RNAs and the mechanisms of their interactions in gastric tumorigenesis. A better understanding of epigenetic regulation would likely facilitate the development of novel therapeutic approaches targeting specific epigenetic regulators in GC.

Study on pharmacokinetic interactions between SHR2554 and itraconazole in healthy subjects: A single-center, open-label phase I trial

BACKGROUND

SHR2554, a novel oral Enhancer of Zeste Homolog 2 inhibitor, shows broad-spectrum anti-tumor efficacy in preclinical studies. As SHR2554 is mainly metabolized by CYP3A4, it is helpful to conduct research on the effects of itraconazole, a strong inhibitor of CYP3A4-metabolizing enzymes, on the pharmacokinetic characteristics and safety of SHR2554.

METHODS

We conducted a single-center, open-label pharmacokinetic study of itraconazole on SHR2554 in 18 healthy Chinese subjects. Subjects were orally administrated SHR2554 50 mg on Day 1, itraconazole 200 mg Quaque Die (QD) from Days 4 to 7, SHR2554 50 mg co-administrated with itraconazole 200 mg on Day 8, and itraconazole 200 mg QD from Days 9 to 12. Then, 4 ml of venous blood was collected at predetermined time points. Plasma SHR2554 concentrations were analyzed using a validated high-performance liquid chromatography tandem mass spectrometry method. Pharmacokinetic parameters were calculated using Phoenix WinNonlin v8.1.

RESULTS

The C_max of SHR2554 alone and in combination was 10.197 ± 7.0262 ng·ml^-1 versus 70.538 ± 25.0219 ng·ml^-1 , AUC_0-∞ was 50.99 ± 19.358 h·ng·ml^-1 versus 641.53 ± 319.538 h·ng·ml^-1 , and AUC_0-t was 28.70 ± 18.913 h·ng·ml^-1 versus 612.13 ± 315.720 h·ng·ml^-1 . Co-administration of SHR2554 and itraconazole caused 7.73-, 12.47-, and 23.75-fold adjusted geometric mean ratios increases in SHR2554 C_max , AUC_0-∞ and AUC_0-t respectively. The co-administration regimen was well tolerated and had a good safety profile.

CONCLUSIONS

Compared with a single dose of SHR2554 50 mg, the exposure of SHR2554 in vivo was significantly affected by the combined administration of itraconazole.

M5C-Related lncRNA Predicts Lung Adenocarcinoma and Tumor Microenvironment Remodeling: Computational Biology and Basic Science

Purpose: Epigenetic RNA modification regulates gene expression post-transcriptionally. The aim of this study was to construct a prognostic risk model for lung adenocarcinoma (LUAD) using long non-coding RNAs (lncRNAs) related to m5C RNA methylation. Method: The lncRNAs regulated by m5C methyltransferase were identified in TCGA-LUAD dataset using Pearson correlation analysis (coefficient > 0.4), and clustered using non-negative matrix decomposition. The co-expressing gene modules were identified by WGCNA and functionally annotated. The prognostically relevant lncRNAs were screened by LASSO regression and a risk model was constructed. LINC00628 was silenced in the NCI-H460 and NCI-H1299 cell lines using siRNA constructs, and migration and invasion were assessed by the Transwell and wound healing assays respectively. Results: We identified 185 m5C methyltransferase-related lncRNAs in LUAD, of which 16 were significantly associated with overall survival. The lncRNAs were grouped into two clusters on the basis of m5C pattern, and were associated with significant differences in overall and disease-free survival. GSVA revealed a close relationship among m5C score, ribosomes, endolysosomes and lymphocyte migration. Using LASSO regression, we constructed a prognostic signature consisting of LINC00628, LINC02147, and MIR34AHG. The m5C-lncRNA signature score was closely related to overall survival, and the accuracy of the predictive model was verified by the receiver operating characteristic curve and decision curve analysis. Knocking down LINC00628 in NCI-H460 and NCI-H1299 cells significantly reduced their migration and invasion compared to that of control cells. Conclusion: We constructed a prognostic risk model of LUAD using three lncRNAs regulated by m5C methyltransferase, which has potential clinical value.

Cross-Talk Between m6A- and m5C-Related lncRNAs to Construct a Novel Signature and Predict the Immune Landscape of Colorectal Cancer Patients

BACKGROUND

N6-methyladenosine (m6A) and 5-methylcytosine (m5C) can modify long non-coding RNAs (lncRNAs), thereby affecting tumorigenesis and tumor progression. However, there is a lack of knowledge regarding the potential roles and cross-talk of m6A- and m5C-related lncRNAs in the tumor microenvironment (TME) and their effect on prognosis.

METHODS

We systematically evaluated the expression patterns of m6A- and m5C-related lncRNAs in 1358 colorectal cancer (CRC) samples from four datasets. Consensus clustering was conducted to identify molecular subtypes of CRC, and the clinical significance, TME, tumor-infiltrating immune cells (TIICs), and immune checkpoints in the different molecular subtypes were analyzed. Finally, we established a m6A- and m5C-related lncRNA signature and a prognostic nomogram.

RESULTS

We identified 141 m6A- and m5C-related lncRNAs by co-expression analysis, among which 23 lncRNAs were significantly associated with the overall survival (OS) of CRC patients. Two distinct molecular subtypes (cluster A and cluster B) were identified, and these two distinct molecular subtypes could predict clinicopathological features, prognosis, TME stromal activity, TIICs, immune checkpoints. Next, a m6A- and m5C-related lncRNA signature for predicting OS was constructed, and its predictive capability in CRC patients was validated. We then constructed a highly accurate nomogram for improving the clinical applicability of the signature. Analyses of clinicopathological features, prognosis, TIICs, cancer stem cell (CSC), and drug response revealed significant differences between two risk groups. In addition, we found that patients with a low-risk score exhibited enhanced response to anti-PD-1/L1 immunotherapy. Functional enrichment analysis showed that these lncRNAs related to the high-risk group were involved in the development and progression of CRC.

CONCLUSIONS

We conducted a comprehensive analysis of m6A- and m5C-related lncRNAs in CRC and revealed their potential functions in predicting tumor-immune-stromal microenvironment, clinicopathological features, and prognosis, and determined their role in immunotherapy. These findings may improve our understanding of the cross-talk between m6A- and m5C-related lncRNAs in CRC and pave a new road for prognosis assessment and more effective immunotherapy strategies.

LINC00628 is differentially expressed between lung adenocarcinoma and squamous cell carcinoma and is associated with the prognosis of NSCLC

Non-small cell lung cancer (NSCLC) remains the most frequent malignancy worldwide, and lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) represent two major subtypes. LINC00628 has been demonstrated to promote LUAD progression; however, its clinical role in NSCLC remains elusive. The aim of the present study was to analyze the expression of long intergenic non-protein coding RNA 628 (LINC00628) in NSCLC, including in the LUAD and LUSC subtypes. In addition, its roles in NSCLC development and prognosis were also examined. Data from The Cancer Genome Atlas (TCGA) database were first used to assess the expression and prognostic potential in both LUAD and LUSC, then LINC00628 expression in 128 NSCLC tissues was measured using reverse transcription-quantitative PCR. A receiver operating characteristic curve was used to assess the ability of LINC00628 to discriminate between patients with LUAD and LUSC. Kaplan-Meier curves were used to analyze the relationship between LINC00628 expression and the overall survival of patients. Cox regression analysis was used to explore the potential prognostic factors that might be independently associated with NSCLC overall survival. Both in silico and tissue analysis data indicated that the expression of LINC00628 was significantly upregulated in NSCLC tissue compared with matched normal controls (P<0.001). LINC00628 expression levels were also significantly higher in LUAD cases than in patients with LUSC (P<0.001). In addition, LINC00628 could discriminate LUAD from LUSC cases. The expression of LINC00628 was significantly associated with tumor size (P=0.013), histological type (P=0.009), lymph node metastasis (P=0.021) and TNM stage (P=0.008). Survival analysis based on data from both TCGA and patients included in the present study identified an association between LINC00628 and overall survival in LUAD, but this relationship was not observed in LUSC for TCGA data. Cox regression analysis demonstrated that high LINC00628 expression was associated with poor overall survival in patients with LUAD (P=0.001), but not in patients with LUSC (P=0.088). In conclusion, LINC00628 expression was upregulated in NSCLC and associated with patient prognosis. Patients with LUAD had higher LINC00628 expression levels than those with LUSC, and increased LINC00628 served as an independent prognostic factor in LUAD, but not LUSC.

Identification of a Ferroptosis-Related LncRNA Signature as a Novel Prognosis Model for Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is a highly heterogeneous malignancy, which makes prognosis prediction of LUAD very challenging. Ferroptosis is an iron-dependent cell death mechanism that is important in the survival of tumor cells. Long non-coding RNAs (lncRNAs) are considered to be key regulators of LUAD development and are involved in ferroptosis of tumor cells, and ferroptosis-related lncRNAs have gradually emerged as new targets for LUAD treatment and prognosis. It is essential to determine the prognostic value of ferroptosis-related lncRNAs in LUAD. In this study, we obtained RNA sequencing (RNA-seq) data and corresponding clinical information of LUAD patients from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database and ferroptosis-related lncRNAs by co-expression analysis. The best predictors associated with LUAD prognosis, including C5orf64, LINC01800, LINC00968, LINC01352, PGM5-AS1, LINC02097, DEPDC1-AS1, WWC2-AS2, SATB2-AS1, LINC00628, LINC01537, LMO7DN, were identified by Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression analysis, and the LUAD risk prediction model was successfully constructed. Kaplan-Meier analysis, receiver operating characteristic (ROC) time curve analysis and univariate and multivariate Cox regression analysis and further demonstrated that the model has excellent robustness and predictive ability. Further, based on the risk prediction model, functional enrichment analysis revealed that 12 prognostic indicators involved a variety of cellular functions and signaling pathways, and the immune status was different in the high-risk and low-risk groups. In conclusion, a risk model of 12 ferroptosis related lncRNAs has important prognostic value for LUAD and may be ferroptosis-related therapeutic targets in the clinic.

Long noncoding RNA LINC00982 upregulates CTSF expression to inhibit gastric cancer progression via the transcription factor HEY1

Upregulating the expression of long noncoding RNA LINC00982 controlled cell proliferation in gastric cancer, but the regulatory molecular mechanisms are yet to be expounded. We here aimed to elaborate how LINC00982 regulated the malignancy of gastric cancer cells. RT-qPCR and Western blot analysis were used to detect the expression of LINC00982 and cathepsin F (CTSF) in gastric cancer tissues and cells. Modulatory effect of LINC00982 on gastric cancer cells was assessed by CCK-8, colony formation, Transwell migration, and invasion assays. The relationship between LINC00982, YRPW motif 1 (HEY1), and CTSF was examined by RNA-binding protein immunoprecipitation, luciferase assay, and chromatin immunoprecipitation, and their interaction in the regulation of gastric cancer cellular functions was analyzed by performing gain-of-function and rescue assays. The nude mouse model of tumor formation was developed to examine the effects of LINC00982 on tumorigenesis. LINC00982 was lowly expressed in gastric cancer tissues, whereas its overexpression impaired the proliferative, migratory, and invasive properties of gastric cancer cells. Furthermore, LINC00982 could bind to transcription factor HEY1 and inhibited its expression. Through blocking the binding of HEY1 to CTSF promoter, LINC00982 promoted the expression of CTSF. Overexpression of HEY1 or inhibition of CTSF could reverse the antitumor effects of LINC00982 on gastric cancer, which were further demonstrated in vivo. All these taken together, LINC00982 acted as a tumor suppressor in gastric cancer, which is therefore suggested to be a potential antitumor target for gastric cancer.NEW & NOTEWORTHY We identified LINC00982 as a promising antitumor target for the treatment of patients with gastric cancer. We also determined a regulatory network involved in the pathophysiology of gastric cancer wherein LINC00982 could bind to HEY1 to impair its binding to cathepsin F (CTSF) promoter and hence promote CTSF expression, which aids in better understanding of molecular mechanisms related to gastric tumorigenesis.

Knockdown of lincRNA PADNA promotes bupivacaine-induced neurotoxicity by miR-194/FBXW7 axis

BACKGROUND

The aim of the study was to explore the function and mechanism of lincRNA PADNA in bupivacaine-induced neurotoxicity.

METHODS

Mouse DRG neurons were cultured in vitro and treated with bupivacaine to establish a neurotoxicity model. Caspase3 activity, cell viability, and TUNEL assays were analyzed to assess the role of lincRNA PADNA. A dual-luciferase reporter assay was used to determine the binding target of lincRNA PANDA.

RESULTS

The expression of lincRNA PADNA was significantly increased with increasing concentrations of bupivacaine. Functional analysis revealed that knockdown of lincRNA PADNA increased caspase3 activity and inhibited cell viability. Western blot analysis showed that knockdown of lincRNA PADNA promoted cleaved caspase3 levels. We also revealed that lincRNA PADNA may bind with miR-194. Knockdown of miR-194 rescued the function of lincRNA PADNA, suggesting that lincRNA PADNA may sponge miR-194. In addition, we provided new evidence that the lincRNA PADNA/miR-194/FBXW7 axis plays an important role in the neurotoxicity process.

CONCLUSION

We performed comprehensive experiments to verify the function and mechanism of lincRNA PADNA in bupivacaine-induced neurotoxicity. Our study provides new evidence and clues for the prevention of neurotoxicity.

lncRNA SPRY4-IT1 Regulates Cell Proliferation and Migration by Sponging miR-101-3p and Regulating AMPK Expression in Gastric Cancer

Increasing evidence indicates that long noncoding RNA SPRY4 intronic transcript 1 (lncRNA SPRY4-IT1) has been reported to be associated with the progression of several cancers, but its expression level and the function of SPRY4-IT1 in the progression of gastric cancer (GC) have been rarely reported. Here we found that SPRY4-IT1 was upregulated in GC. In vitro experiments revealed that SPRY4-IT1 knockdown significantly inhibited GC cell proliferation by causing G1 arrest and promoting apoptosis, whereas SPRY4-IT1 overexpression promoted cell growth. Further functional assays indicated that SPRY4-IT1 overexpression significantly promoted cell migration and invasion. Bioinformatics analysis predicted that there is a SPRY4-IT1/miR-101-3p/AMPK axis in GC progression. A dual-luciferase reporter system validated the direct interaction of SPRY4-IT1, miR-101-3p, and AMPK. Western blot verified that the inhibition of SPRY4-IT1 decreased AMPK expression. Furthermore, silencing SPRY4-IT1 suppressed GC growth in vivo. Importantly, we demonstrated that SPRY4-IT1 was upregulated in serum exosomes from GC patients and correlated with cancer metastasis. Altogether, silencing SPRY4-IT1 suppresses the progression of GC by interacting with miR-101-3p and decreasing inhibiting AMPK expression. Taken together, our study demonstrates that SPRY4-IT1 could act as a potential therapeutic target for GC patients.

LINC00628 suppresses migration and invasion of hepatocellular carcinoma by its conserved region interacting with the promoter of VEGFA

Accumulated evidence revealed that numerous long noncoding RNAs (lncRNAs) have been found to be involved in the development and progression of hepatocellular carcinoma (HCC). LINC00628, a member of lncRNAs, has been reported to act as a tumor suppressor in gastric cancer and breast cancer. However, its potential role in HCC still remains unknown. Herein, we characterized the function of LINC00628 in HCC. Our investigation has revealed that LINC00628 were dramatically decreased in HCC tissues and cells, and inhibited the migration and invasion of HCC cells in vitro and in vivo. Moreover, LINC00628 exerted its tumor suppressive function by repressing the vascular endothelial growth factor A (VEGFA) promoter activity. A highly conserved region element in LINC00628 was identified by a cross-species comparative analysis, which is required for LINC00628 exerted its function. Dual-luciferase reporter assay showed that the conserved sequence mediated the interaction with a specific region of VEGFA promoter, resulting in a decrease of VEGFA expression. In conclusion, our results demonstrated that LINC00628 could function as a tumor suppressor in HCC via its conserved sequence elements interacting with a particular region of VEGFA promoter, suggesting that LINC00628 may serve as a novel promising target for diagnosis and therapy in HCC.

Overexpression of lncRNA Gm2691 attenuates apoptosis and inflammatory response after myocardial infarction through PI3K/Akt signaling pathway

Acute myocardial infarction is one of the most threatening disease in the world. In previous studies, numerous dysregulated lncRNAs exposed to ischemic reperfusion injury have been identified. In this differential lncRNAs, Gm2691 attracted our attention due to its high fold change. The aim of the study was to investigate the function and mechanism of lncRNA Gm2691 in ischemic reperfusion injury. AnaeroPack anaerobic system treated neonatal rat ventricular cardiomyocytes were used to analyze the function of lncRNA Gm2691 in vitro. Tunel, Caspase3, and inflammation markers were detected to evaluate apoptosis and inflammatory response. Rat acute myocardial infarction was performed to elucidate the function of lncRNA Gm2691 in vivo. The results showed that LncRNA Gm2691 improved the cardiac function and attenuated the inflammatory response in vivo. We also found that lncRNA Gm2691 reduced the apoptosis and improved cell survival rates in anaeroPack anaerobic system treated neonatal rat ventricular cardiomyocytes. Western blot analysis revealed that lncRNA Gm2691 decreased Akt and ERK1/2 activities, suggesting that lncRNA Gm2691 may functioned through Akt signaling pathway. We verified the function and mechanism of lncRNA Gm2691 and provide evidence that lncRNA Gm2691 may play important role in ischemic reperfusion injury, and understanding the precise role of Gm2691 will undoubtedly shed new light on the clinical treatment.

Long noncoding RNAs in cancer cells

Long noncoding RNA (lncRNA) has recently been investigated as key modulators that regulate many biological processes in human cancers via diverse mechanisms. LncRNAs can interact with macromolecules such as DNA, RNA, or protein to exert cellular effects and to act as either tumor promoters or tumor suppressors in various malignancies. Moreover, the aberrant expression of lncRNAs may be detected in multiple cancer phenotypes by employing the rapidly developing modern gene chip technology and bioinformatics analysis. Herein, we highlight the mechanisms of action of lncRNAs, their functional cellular roles and their involvement in cancer progression. Finally, we provide an overview of recent progress in the lncRNA field and future potential for lncRNAs as cancer diagnostic markers and therapeutics.

Knockdown of linc00152 inhibits the progression of gastric cancer by regulating microRNA-193b-3p/ETS1 axis

BACKGROUND

Gastric cancer (GC) is a serious threat for public health worldwide. Long non-coding RNA (lncRNA) linc00152 has been well reported to be an oncogene and a potential biomarker in multiple cancers including GC. However, the molecular mechanisms of linc00152 in GC development need to be further investigated.

METHODS

RT-qPCR assay was employed to detect the levels of linc00152, microRNA-193b-3p (miR-193b-3p) and ETS1 mRNA. ETS1 protein level was measured by western blot assay. Cell proliferative, migratory and invasive capacities were assessed by colony formation together with CCK-8 assays, transwell migration and invasion assays, respectively. Bioinformatics analyses and luciferase reporter assay were used to explore whether miR-193b-3p could interact with linc00152 or ETS1 3'UTR. The roles and molecular basis of linc00152 silence on the growth of GC xenograft tumors were tested in vivo.

RESULTS

Linc00152 expression was notably upregulated in GC tissues and cells. The proliferative, migratory and invasive abilities of GC cells were weakened by linc00152 depletion, miR-193b-3p overexpression or ETS1 knockdown. Linc00152 upregulation inhibited miR-193b-3p expression by direct interaction and abolished miR-193b-3p-mediated anti-proliferation, anti-migration and anti-invasion effects in GC cells. ETS1 was a target of miR-193b-3p and linc00152 could promote ETS1 expression by downregulating miR-193b-3p. In vivo experiments further validated that linc00152 knockdown inhibited the growth of GC xenograft tumors by upregulating miR-193b-3p and downregulating ETS1.

CONCLUSION

Knockdown of linc00152 inhibited GC progression by sequestering miR-193b-3p from ETS1 in vitro and in vivo, elucidating a novel molecular mechanism of linc00152 in promoting GC carcinogenesis.

Prognostic value of long noncoding RNAs in gastric cancer: a meta-analysis

Background

In the last few years, accumulating evidence has indicated that numerous long noncoding RNAs (lncRNAs) are abnormally expressed in gastric cancer (GC) and are associated with the survival of GC patients. This study aimed to conduct a meta-analysis on 19 lncRNAs (AFAP1 antisense RNA 1 [AFAP1-AS1], CDKN2B antisense RNA 1 [ANRIL], cancer susceptibility 15 [CASC15], colon cancer associated transcript 2 [CCAT2], gastric adenocarcinoma associated, positive CD44 regulator, long intergenic noncoding RNA [GAPLINC], H19, imprinted maternally expressed transcript [H19], HOX transcript antisense RNA [HOTAIR], HOXA distal transcript antisense RNA [HOTTIP], long intergenic non-protein coding RNA 673 [LINC00673], metastasis-associated lung adenocarcinoma transcript 1 [MALAT1], maternally expressed 3 [MEG3], promoter of CDKN1A antisense DNA damage activated RNA [PANDAR], Pvt1 oncogene [PVT1], SOX2 overlapping transcript [Sox2ot], SPRY4 intronic transcript 1 [SPRY4-IT1], urothelial cancer associated 1 [UCA1], X inactive specific transcript [XIST], ZEB1 antisense RNA 1 [ZEB1-AS1] and ZNFX1 antisense RNA 1 [ZFAS1]) to systematically estimate their prognostic value in GC.

Methods

The qualified literature was systematically searched in PubMed, Web of Science, Embase and Cochrane Database of Systematic Reviews (up to March 16, 2018), and one meta-analysis relating to the relationship between lncRNA expression and overall survival (OS) of GC patients was performed. The only evaluation criterion of survival results was OS.

Results

A total of 6,095 GC patients and 19 lncRNAs from 51 articles were included in the present study. Among the listed 19 lncRNAs, 18 lncRNAs (other than SPRY4-IT1) showed a significantly prognostic value (P<0.05).

Conclusion

This meta-analysis suggested that the abnormally expressed lncRNAs (AFAP1-AS1, ANRIL, CASC15, CCAT2, GAPLINC, H19, HOTAIR, HOTTIP, LINC00673, MALAT1, MEG3, PANDAR, PVT1, Sox2ot, UCA1, XIST, ZEB1-AS1 and ZFAS1) were significantly associated with the survival of GC patients, among which AFAP1-AS1, CCAT2, LINC00673, PANDAR, PVT1, Sox2ot, ZEB1-AS1 and ZFAS1 were strong candidates in predicting the prognosis of GC patients.

Long non-coding RNA AK058003, as a precursor of miR-15a, interacts with HuR to inhibit the expression of γ-synuclein in hepatocellular carcinoma cells

Long non-coding RNAs (lncRNAs) have been identified as critical players in multiple cancers and lncRNAs are tightly linked to cancer progression. However, only little amount of lncRNAs have been identified to participate in the molecular mechanisms of the progression of hepatocellular carcinoma. In this study, we found that lncRNA-AK058003 is down-regulated in hepatocellular carcinoma tissues and it is associated with the relapse and metastasis of the cancer. Furthermore, lncRNA-AK058003 acts as a tumor suppressor, suppressing hepatocellular carcinoma cell proliferation and metastasis in vitro and in vivo. lncRNA-AK058003 can reduce mRNA stabilizing protein HuR, which results in the inhibition of the expression of γ-synuclein. In addition, a bioinformatics study indicated that γ-synuclein is a target of miR-15a. To verify whether lncRNA-AK058003 plays a role in miR-15a-mediated inhibition of γ-synuclein, we demonstrated that lncRNA-AK058003 is very likely to be a precursor of miR-15a. Collectively, lncRNA-AK058003 can reduce the expression of mRNA stabilizing protein HuR and act as a precursor of miR-15a to suppress γ-synuclein-mediated cell proliferation and the metastasis of hepatocellular carcinoma.

Keratin17 Promotes Tumor Growth and is Associated with Poor Prognosis in Gastric Cancer

Krt17 is a 48kDa protein member of keratin family. Previous literatures have demonstrated Krt17 may play a promotive role in the progression of various malignancies. However, the exact function of Krt17 in the carcinogenesis and the progression of gastric cancer (GC) remains unknown. In the present study, the expression of Krt17 in 20 fresh GC and matched normal tissues were detected and Krt17 was found to be significantly increased in GC tissues compared to normal tissues. And then the immunochemistry was performed to investigate the Krt17 expression in 569 GC tissue specimens, we found that the expression of Krt17 was remarkably positively correlated with the tumor size (P < 0.01), depth of invasion (T) (P < 0.001), lymph node metastasis (N) (P < 0.001), tumor node metastasis (TNM) stage (P < 0.001) and vascular invasion (P < 0.05). High expression of Krt17 predicted a poor prognosis of GC patients. In addition, we showed silencing of Krt17 inhibited GC cell proliferation, migration and invasion, and induced cell apoptosis by altering Bcl2 family protein expression and cleaved caspase3 upregulation. Moreover, silencing of Krt17 led to cell cycle arrest at G1/S stage by decreasing cyclin E1 and cyclin D expression. In conclusion, our findings revealed Krt17 can be used as a novel predictive biomarker, thus providing a novel therapeutic target for GC patients.

EZH2 in Cancer Progression and Potential Application in Cancer Therapy: A Friend or Foe?

Enhancer of zeste homolog 2 (EZH2), a histone methyltransferase, catalyzes tri-methylation of histone H3 at Lys 27 (H3K27me3) to regulate gene expression through epigenetic machinery. EZH2 functions as a double-facet molecule in regulation of gene expression via repression or activation mechanisms, depending on the different cellular contexts. EZH2 interacts with both histone and non-histone proteins to modulate diverse physiological functions including cancer progression and malignancy. In this review article, we focused on the updated information regarding microRNAs (miRNAs) and long non coding RNAs (lncRNAs) in regulation of EZH2, the oncogenic and tumor suppressive roles of EZH2 in cancer progression and malignancy, as well as current pre-clinical and clinical trials of EZH2 inhibitors.

LINC00978 predicts poor prognosis in breast cancer patients

Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death among women worldwide. Long non-coding RNAs (lncRNAs) are a class of non-coding RNAs in the human genome that involves in breast cancer development and progression. Here, we identify a lncRNA, LINC00978, which is upregulated in breast cancer cell lines and tissues compared with corresponding controls. Furthermore, LINC00978 expression is negatively associated with hormone receptor (HR) status in 195 breast cancer patients studied (p = 0.033). Kaplan–Meier survival analysis shows that patients with high LINC00978 expression have poorer disease-free survival (DFS) than those with low LINC00978 expression (p = 0.012), and multivariate analysis identifies LINC00978 as an independent prognostic factor in breast cancer (p = 0.008, hazard ratio [HR] = 2.270, 95% confidence interval [CI] 1.237–4.165). Our study indicates that LINC00978 may be an oncogene in breast cancer, and can serve as a potential biomarker to predict prognosis in breast cancer patients.

Long Noncoding RNA Taurine-Upregulated Gene 1 Promotes Cell Proliferation and Invasion in Gastric Cancer via Negatively Modulating miRNA-145-5p

Long noncoding RNA (lncRNA) taurine-upregulated gene 1 (TUG1) is involved in the development and carcinogenesis of various tumors, suggesting the diagnostic potential of TUG1 in these cancers. However, the exact role of TUG1 and its underlying mechanism in gastric cancer (GC) remain unknown. In this study, the expression of TUG1 and miR-145-5p in GC cell lines and nonmalignant gastric epithelial cell lines was detected by qRT-PCR. BGC-823 and SGC-7901 cells were transfected with si-TUG1, pcDNA 3.1-TUG1, miR-145-5p mimics, or matched controls. The biological function of TUG1 and miR-145-5p in GC cell proliferation and invasion in vitro and tumor growth in vivo was investigated by MTT assay, Transwell invasion assay, and tumor xenograft experiments. The regulating relationship between TUG1 and miR-145-5 was confirmed by luciferase reporter assay. The results showed that TUG1 was significantly overexpressed and miR-145-5p was dramatically downregulated in GC cell lines. TUG1 knockdown strikingly inhibited cell proliferation and invasion in vitro and markedly suppressed tumor growth in vivo. Furthermore, TUG1 could directly bind to miR-145-5p and repress miR-145-5p expression. TUG1 overexpression significantly relieved the inhibition on GC cell proliferation and invasion in vitro and tumor growth in vivo, mediated by miR-145-5p overexpression. In conclusion, TUG1 promotes cell proliferation and invasion in GC via negatively modulating miRNA-145-5p, which undoubtedly contributes to understanding the mechanism of GC occurrence and development.