lncRNA-UCA1 enhances cell proliferation through functioning as a ceRNA of Sox4 in esophageal cancer

MicroRNA-204-5p: A pivotal tumor suppressor

MicroRNAs (miRNAs) are a class of non-coding single-stranded RNA molecules with a length of approximately 18-25 nt nucleotides that regulate gene expression post-transcriptionally. MiR-204-5p originates from the sixth intron of the transient receptor potential cation channel subfamily M member 3 (TRPM3) gene. MiR-204-5p is frequently downregulated in various cancer types and is related to the clinicopathological characteristics and prognosis of cancer patients. So far, many studies have determined that miR-204-5p functions as a tumor suppressor for its extensive and powerful capacity to inhibit tumor proliferation, metastasis, autophagy, and chemoresistance in multiple cancer types. MiR-204-5p appears to be a promising prognostic biomarker and a therapeutic target for human cancers. This review summarized the latest advances on the role of miR-204-5p in human cancers.

Long Non-Coding RNA in Esophageal Cancer: A Review of Research Progress

In recent years, there has been significant progress in the diagnosis and treatment of esophageal cancer. However, owing to the lack of early diagnosis strategies and treatment targets, the prognosis of patients with esophageal cancer remains unsatisfactory. There is an urgent need to identify novel biomarkers and treatment targets for esophageal cancer. With the development of genomics, long-chain non-coding RNAs (LncRNAs), which were once considered transcriptional “noise,” are being identified and characterized rapidly in large numbers. Recent research shows that LncRNAs are closely related to a series of steps in tumor development and play an important regulatory role in DNA replication, transcription, and post-transcriptional regulation. The abnormal expression of LncRNAs leads to tumor cell proliferation, migration, invasion, and treatment resistance. This review focuses on the latest progress in research on the abnormal expression and functional mechanisms of LncRNAs in esophageal cancer. Further, it discusses the potential applications of these findings towards achieving an early diagnosis, improving treatment efficacy, and evaluating the prognosis of esophageal cancer.

Transcription factor SOX4 facilitates BMP2-regulated gene expression during invasive trophoblast differentiation

The interplay between growth factors, signaling pathways and transcription factors during placental development is key to controlling trophoblast differentiation. Bone morphogenetic protein 2 (BMP2) has been implicated in trophoblast invasion and spiral artery remodeling during early placental development. However, the molecular mechanisms by which these are accomplished have not been fully elucidated, particularly for transcriptional regulation of key transcription factors. Here, we identified SOX4 as a direct target gene induced by BMP2 in first-trimester placental trophoblasts. Analysis of single-cell RNA-seq data from first-trimester placentas and decidua tissues revealed that SOX4 expression is mainly localized in extravillous trophoblast and decidual stromal cells. Moreover, gain- and loss-of-function approaches demonstrated that SOX4 exerts a pro-invasive role in human trophoblasts, and this effect contributes to BMP2-enhanced trophoblast invasion. Importantly, we found that SOX4 was required for BMP2-induced regulation of a subset of genes associated with cell migration and extracellular matrix organization. We also show that SOX4-dependent regulation of the BMP2 target SERPINE2 occurs via binding of SOX4 to regulatory elements such as enhancers, thereby promoting BMP2-induced trophoblast invasion. In conclusion, these findings uncover a novel mechanism involving SOX4 that shapes the BMP2-regulated transcriptional network during invasive trophoblast development.

Non-coding RNAs as biomarkers for hepatocellular carcinoma-A systematic review

Hepatocellular carcinoma (HCC) is the sixth most common malignancy in the world and the fourth leading cause of cancer-related death, and its incidence is increasing globally. Despite significant advances in treatment strategies for HCC, the prognosis is still poor due to its high recurrence rate. Therefore, there is an urgent need to understand the pathogenesis of HCC and further develop new therapies to improve the prognosis and quality of life of HCC patients. MicroRNAs (miRNAs, miRs) are small non-coding RNAs involved in post-transcriptional regulation of gene expression that is abnormally expressed in cancer-associated genomic regions or vulnerable sites. More and more findings have shown that miRNAs are important regulatory factors of mRNA expression in HCC, and they are receiving more and more attention as a possible key biomarker of HCC. This review mainly summarizes the potential applied value on miRNAs as diagnostic, drug resistant, prognostic, and therapeutic biomarkers in the diagnosis, therapy, and prognosis of HCC. Also, we summarize the research value of long non-coding RNA (lncRNAs), circular RNAs (circRNAs), and miRNAs network in HCC as novel biomarkers, aiming at providing some references for the therapy of HCC.

Prognostic value of long noncoding RNA urothelial carcinoma-associated 1 in esophageal carcinoma: A protocol for meta-analysis, TCGA data and bioinformatics analysis

BACKGROUND

Currently, an increasing number of long noncoding RNAs (LncRNAs) have been reported to be abnormally expressed in human carcinomas and play a vital role in tumourigenesis. Some studies have been carried out to investigate the influence of the expression of LncRNA human urothelial carcinoma associated 1 (UCA1) on prognosis and clinical significance in patients with esophageal cancer, but the results are contradictory and uncertain. A meta-analysis and was conducted with controversial data to accurately assess the issue. We collected relevant TCGA data to further testify the result. In addition, bioinformatics analysis was conducted to investigate the mechanism and related pathways of LncRNA UCA1 in esophageal carcinoma.

METHODS

Wanfang, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, the Chongqing VIP Chinese Science and Technology Periodical Database, PubMed, Embase, and Web of Science were thoroughly searched for relevant information. Two reviewers independently performed data extraction and literature quality evaluation. Odd ratio and its 95% confidence intervals were applied to evaluate the relationship between LncRNA UCA1 and clinicopathological characteristics of esophageal carcinoma patients. Hazard ratios and its 95% confidence intervals were adopted to assess the prognostic effects of LncRNA UCA1 on overall survival and disease-free survival. Meta-analysis was performed with Stata 14.0 software. To further assess the function of LncRNA UCA1 in esophageal carcinoma, relevant data from The Cancer Genome Atlas (TCGA) database was collected. Three databases, miRWalk, TargetScan, and miRDB, were used for prediction of target genes. Genes present in these 3 databases were considered as predicted target genes of LncRNA UCA1. Venny 2.1 were used for intersection analysis. Subsequently, GO, KEGG, and PPI network analysis were conducted based on the overlapping target genes of LncRNA UCA1 to explore the possible molecular mechanism in esophageal carcinoma.

RESULTS

This study provides a high-quality medical evidence for the correlation between LncRNA UCA1 expression and overall survival, and between disease-free survival and clinicopathological features. Based on bioinformatics analysis, this study enhanced the understanding of the mechanism and related pathways of LncRNA UCA1 in esophageal carcinoma.

CONCLUSION

The study provides updated evidence to evaluate whether the expression of LncRNA UCA1 is in association with poor prognosis in patients with esophageal carcinoma.

ETHICS AND DISSEMINATION

The private information from individuals will not be published. This systematic review also should not damage participants' rights. Ethical approval is not available. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/8MCHW.

Long Noncoding RNA UCA1 in Gastrointestinal Cancers: Molecular Regulatory Roles and Patterns, Mechanisms, and Interactions

The rising trend of gastrointestinal (GI) cancer has become a global burden due to its aggressive nature and poor prognosis. Long noncoding RNAs (lncRNAs) have recently been reported to be overexpressed in different GI cancers and may contribute to cancer progression and chemoresistance. They are featured with more than 200 nucleotides, commonly polyadenylated, and lacking an open reading frame. LncRNAs, particularly urothelial carcinoma-associated 1 (UCA1), are oncogenes involved in regulating cancer progression, such as cell proliferation, invasion, migration, and chemoresistance, particularly in GI cancer. This review was aimed to present an updated focus on the molecular regulatory roles and patterns of lncRNA UCA1 in progression and chemoresistance of different GI cancers, as well as deciphering the underlying mechanisms and its interactions with key molecules involved, together with a brief presentation on its diagnostic and prognostic values. The regulatory roles of lncRNA UCA1 are implicated in esophageal cancer, gastric cancer, pancreatic cancer, hepatobiliary cancer, and colorectal cancer, where they shared similar molecular mechanisms in regulating cancer phenotypes and chemoresistance. Comparatively, gastric cancer is the most intensively studied type in GI cancer. LncRNA UCA1 is implicated in biological roles of different GI cancers via interactions with various molecules, particularly microRNAs, and signaling pathways. In conclusion, lncRNA UCA1 is a potential molecular target for GI cancer, which may lead to the development of a novel chemotherapeutic agent. Hence, it also acts as a potential diagnostic and prognostic marker for GI cancer patients.

The Functional Role of Long Non-coding RNA UCA1 in Human Multiple Cancers: a Review Study

In various cancers, high-grade tumor and poor survival rate in patients with upregulated lncRNAs UCA1 have been confirmed. Urothelial carcinoma associated 1 (UCA1) is an oncogenic non-coding RNA with a length of more than 200 nucleotides. The UCA1 regulate critical biological processes that are involved in cancer progression, including cancer cell growth, invasion, migration, metastasis, and angiogenesis. So It should not surprise that UCA1 overexpresses in variety of cancers type, including pancreatic cancer, ovarian cancer, gastric cancer, colorectal cancer, breast cancer, prostate cancer, endometrial cancer, cervical cancer, bladder cancer, adrenal cancer, hypopharyngeal cancer, oral cancer, gallbladder cancer, nasopharyngeal cancer, laryngeal cancer, osteosarcoma, esophageal squamous cell carcinoma, renal cell carcinoma, cholangiocarcinoma, leukemia, glioma, thyroid cancer, medulloblastoma, hepatocellular carcinoma and multiple myeloma. In this article, we review the biological function and regulatory mechanism of UCA1 in several cancers and also, we will discuss the potential of its as cancer biomarker and cancer treatment.

Involvement of long non-coding RNAs in the progression of esophageal cancer

Esophageal cancer (EC) is one of the most common malignant tumors of the digestive system with high incidence and mortality rate worldwide. Therefore, exploring the pathogenesis of EC and searching for new targeted therapies are the current research hotspot for EC treatment. Long non‐coding RNAs (lncRNAs) are endogenous RNAs with more than 200 nucleotides, but without protein‐coding function. In recent years, lncRNAs have gradually become the focuses in the field of non‐coding RNA. Some lncRNAs have been proved to be closely related to the pathogenesis of EC. Many lncRNAs are abnormally expressed in EC and participate in many biological processes including cell proliferation, apoptosis, and metastasis by inhibiting or promoting target gene expression. LncRNAs can also regulate the progression of EC through epithelial‐mesenchymal transformation (EMT), which is closely related to the occurrence, development, and prognosis of EC. In this article, we review and discuss the involvement of lncRNAs in the progression of EC.

Long non-coding RNA MCM3AP-AS1 facilitates colorectal cancer progression by regulating the microRNA-599/ARPP19 axis

Colorectal cancer (CRC) is one of the most aggressive malignancies worldwide. Increasing evidence has indicated that microRNA (miR)-599 is involved in the occurrence and development of different types of tumors, such as breast cancer and glioma. However, the role of miR-599 in CRC remains unclear. Thus, the present study aimed to identify the regulatory mechanism of miR-599 in CRC progression. Reverse transcription-quantitative PCR was used to analyze the expression levels of MCM3AP-AS1, miR-599 and ARPP19, and Cell Counting Kit-8 and Transwell assays were used to determine the cell proliferation and migration of CRC cells. In addition, a Dual-luciferase reporter assay was used to analyze the direct interaction between miR-599 and MCM3AP-AS1 or ARPP19. Reverse transcription-quantitative PCR analysis demonstrated that miR-599 expression decreased in patients with CRC and in CRC cell lines, while miR-599 overexpression inhibited cell proliferation and migration abilities in vitro. MCM3AP-AS1 was identified as a molecular sponge of miR-599, and further investigation indicated that MCM3AP-AS1 silencing inhibited cell proliferation and migration of the CRC cell lines. In addition, ARPP19 was identified as a target gene of miR-599, and MCM3AP-AS1-knockdown decreased ARPP19 mRNA expression and increased miR-599 expression. Furthermore, silencing ARPP19 inhibited the proliferation and migration of the CRC cell lines. The results also demonstrated that MCM3AP-AS1 promoted CRC cell progression by regulating the miR-599/ARPP19 axis. Taken together, the results of the present study suggest that MCM3AP-AS1 may be a novel therapeutic target for patients with CRC.

LncRNA TUG1 promotes esophageal cancer development through regulating PLK1 expression by sponging miR-1294

OBJECTIVES

Esophageal cancer is one of the malignant tumor with poor survival. The 5-year survival rate of esophageal cancer patients remains poor due to limited therapeutic options and the development of drug-resistance. Recent evidence suggests that long non-coding RNAs (lncRNAs) are involved in occurrence and development of tumor, however, the molecular mechanisms of lncRNA taurine-upregulated gene 1 (TUG1) in esophageal cancer remain unknown.

RESULTS

TUG1 was overexpressed in esophageal cancer tissues and cells. The knockdown of TUG1 repressed proliferation and invasion, while promoted apoptosis of esophageal cancer cells by negatively regulating miR-1294 expression. Furthermore, PLK1 was a target mRNA of miR-1294 in esophageal cancer cells. Therefore, the effects of PLK1 silencing on proliferation, apoptosis, and invasion of esophageal cancer cells could be overturned by silencing miR-1294. Additionally, TUG1 silencing inhibited growth of tumor cells in vivo.

CONCLUSIONS

TUG1 was found as oncogenic gene in esophageal cancer. Mechanically, TUG1 attributed to esophageal cancer process by regulating miR-1294/ PLK1 axis.

Silencing of long non-coding RNA LINC01270 inhibits esophageal cancer progression and enhances chemosensitivity to 5-fluorouracil by mediating GSTP1methylation

Esophageal cancer (EC) is a serious digestive malignancy which remains the sixth leading cause of cancer-related deaths worldwide. Emerging evidence suggests the involvement of long non-coding RNAs (lncRNAs) in the tumorigenesis of EC and thus, in this study we explored the potential effects of lncRNA LINC01270 on EC cell proliferation, migration, invasion and, drug resistance via regulation of glutathione S-transferase P1 (GSTP1) methylation. First, we screened out the EC-related differentially expressed lncRNAs, and the expression of our top candidate LINC01270 was quantified in EC tissues and cells. To define the role of LINC01270 in EC progression, we evaluated the proliferation, migration and invasion of EC cells when the LINC01270 was overexpressed or knocked down, in the presence of the GSTP1 methylation inhibitor SGI-1027 and 5-fluorouracil (5-FU). In addition, interaction between LINC01270 and methylation of the GSTP1 promoter was identified. Finally, we assessed transplantable tumor growth in nude mice. LINC01270 was up-regulated and GSTP1 was down-regulated in EC tissues and cells. Silencing of LINC01270 inhibited migration and invasion, and enhanced the sensitivity of 5-FU in EC cells. We found that LINC01270 recruited the DNA methyltransferases DNMT1, DNMT3A and DNMT3B initiating GSTP1 promoter methylation, thereby leading to the proliferation, migration, invasion and drug resistance of EC cells. Moreover, GSTP1 overexpression was observed to reverse the effects of LINC01270 overexpression on EC cells and their response to 5-FU. Taken together, this study shows that inhibition of LINC01270 can lead to suppression of EC progression via demethylation of GSTP1, highlighting this lncRNA as a potential target for EC treatment.

Downregulation of the long noncoding RNA SNHG1 inhibits tumor cell migration and invasion by sponging miR-195 through targeting Cdc42 in oesophageal cancer

Despite the poor prognosis of oesophageal cancer (EC), the molecular mechanisms of EC are still unclear. In recent years, role of lncRNA in cancer development attracted much attention. The present study aimed to investigate the effects of the long noncoding RNA SNHG1 on the migration and invasion of EC cells and the possible mechanisms involved. The effects of SNHG1 on cell proliferation, migration, and invasion were determined and its relationship with miR-195/Cdc42 axis was investigated. It was found SNHG1 and Cdc42 were significantly upregulated, and miR-195 was significantly downregulated in both EC tissues and cell lines. In addition, the inhibition of either SNHG1 or Cdc42 resulted in suppression of cell proliferation, migration, and invasion, while inhibition of miR-195 led to opposite results and reversed the effects of si-SNHG1. We also observed that higher SNHG1 predicted poorer prognosis of EC patients. In summary, inhibition of SNHG1 can suppress the cell migration and invasion of EC cells by sponging miR-195 through targeting Cdc42. This study might provide deeper insights into the SNHG1/miR-195/Cdc42 axis in EC.

Exosomal long non-coding RNA UCA1 functions as growth inhibitor in esophageal cancer

PURPOSE

Esophageal cancer is a highly lethal and broad-spreading malignant tumor worldwide. Exosome-carrying lncRNAs play an essential role in the pathogenesis of various cancers.

RESULTS

The results revealed that the expression of UCA1 was decreased in esophageal cancer tissues and plasma exosomes. UCA1 was enriched in exosomes, and exosomal UCA1 was a promising biomarker for the diagnosis of esophageal cancer with 86.7% sensitivity and 70.2% specificity. Overexpression of UCA1 played anticancer roles in esophageal cancer cells through inhibiting cell proliferation, invasion and migration, and colony formation. Also, exosomal UCA1 was taken up by esophageal cancer cells and inhibited the progression of esophageal cancer in vitro and tumor growth in vivo. Furthermore, exosomal UCA1 could directly target miRNA-613 in esophageal cancer cells.

CONCLUSIONS

The results suggested that exosomal UCA1 inhibits tumorigenesis and progression of esophageal cancer in vitro and in vivo, and might be a promising biomarker for esophageal cancer.

PATIENT AND METHODS

In this study, we determined the expression of UCA1 in esophageal cancer tissues, plasma exosomes of patients with esophageal cancer. We determined the potential of exosomal UCA1 as a biomarker and its effect on the pathogenesis and progression of esophageal cancer in vitro and in vivo.

The interaction mechanism between autophagy and apoptosis in colon cancer

Autophagy and apoptosis play crucial roles in tumorigenesis. Recent studies have shown that autophagy and apoptosis have a cross-talk relationship in anti-tumor therapy. It is well established that apoptosis is one of the main pathways of tumor cell death. While autophagy can occurs in tumors with opposite function: protective autophagy and lethal autophagy. Protective autophagy can inhibit tumor apoptosis induced by anticancer drugs, while lethal autophagy can induce tumor cell apoptosis in cooperation with anticancer drugs. Hence, autophagy and apoptosis have synergistic and antagonistic effects in tumor. Colorectal cancer is a common malignant tumor with high morbidity and mortality. In recent years, colorectal carcinoma has achieved improved clinical efficacy with drug treatment. Nonetheless, increasing drug-resistance limit the treatment efficacy, highlighting the urgency of exploring the molecular events that drive drug resistance. Researchers have found that autophagy is one of the major factors leading to drug resistance in colon cancer. Therefore, elucidating the interaction between autophagy and apoptosis is helpful to improve the efficacy of anticancer drugs in clinical treatment of colorectal cancer. This review attaches great importance to the relationship between autophagy and apoptosis and related factors in colorectal cancer.

Hypoxic Tumor-Derived Exosomal Long Noncoding RNA UCA1 Promotes Angiogenesis via miR-96-5p/AMOTL2 in Pancreatic Cancer

The hypoxic microenvironment, an important feature of solid tumors, promotes tumor cells to release exosomes and enhances tumor angiogenesis. However, the detailed functions of hypoxic exosomes and the mechanisms underlying their effects in pancreatic cancer (PC) remain mysterious. Here, we observed that hypoxic exosomes derived from PC cells promoted cell migration and tube formation of human umbilical vein endothelial cells (HUVECs). The long noncoding RNA (lncRNA) UCA1, a key factor, was highly expressed in exosomes derived from hypoxic PC cells and could be transferred to HUVECs through the exosomes. In addition, the expression levels of UCA1 in exosomes derived from PC patients' serum were higher than in healthy controls and were associated with poor survival of PC patients. Moreover, hypoxic exosomal UCA1 could promote angiogenesis and tumor growth both in vitro and in vivo. With respect to the functional mechanism, UCA1 acted as a sponge of microRNA (miR)-96-5p, relieving the repressive effects of miR-96-5p on the expression of its target gene AMOTL2. Collectively, these results indicate that hypoxic exosomal UCA1 could promote angiogenesis and tumor growth through the miR-96-5p/AMOTL2/ERK1/2 axis and therefore, serve as a novel target for PC treatment.

LINC02418 promotes malignant behaviors in lung adenocarcinoma cells by sponging miR-4677-3p to upregulate KNL1 expression

Background

Lung adenocarcinoma (LAD) is a prevalent type of bronchogenic malignant tumor and one of the most critical factors related to human death. Long noncoding RNAs (lncRNAs) are involved in many complex biological processes and have been emerged as extremely important regulators of various cancers. LINC02418, a novel lncRNA, hasn’t been mentioned in previous studies on cancer development. Therefore, it’s important to define the potential function of LINC02418 in LAD.

Methods

Gene expression was examined by RT-qPCR or western blot. CCK-8, colony formation, TUNEL, and transwell assays were utilized to study the role of LINC02418 in LAD. The interaction of miR-4677-3p with LINC02418 (or KNL1) was verified through luciferase reporter, RIP and RNA pull-down assays.

Results

High expression of LINC02418 was observed in LAD specimens and cells. Downregulation of LINC02418 obstructed the proliferation and motility of LAD cells. Moreover, LINC02418 negatively modulated miR-4677-3p expression and miR-4677-3p overexpression could repress cell proliferation and migration. Moreover, kinetochore scaffold 1 (KNL1) expression was negatively modulated by miR-4677-3p but positively regulated by LINC02418. Furthermore, miR-4677-3p could bind with LINC02418 (or KNL1). Finally, KNL1 overexpression reversed the inhibitory function of LINC02418 deficiency in the malignant behaviors of LAD cells.

Conclusions

LINC02418 contributes to the malignancy in LAD via miR-4677-3p/KNL1 signaling, providing a probable therapeutic direction for LAD.

Silencing of Long Noncoding RNA LINC00324 Interacts with MicroRNA-3200-5p to Attenuate the Tumorigenesis of Gastric Cancer via Regulating BCAT1

PURPOSE

This study was aimed at exploring the effect of long noncoding RNA LINC00324 (LINC00324) on gastric cancer (GC) and the potential molecular mechanisms.

METHODS

The expression of LINC00324 and miR-3200-5p in GC tissues and cells was detected by qRT-PCR. LINC00324 was silenced in GC cells by transfection of si-LINC00324. Then, the proliferation, migration, and invasion of GC cells were analyzed by MTT, wound healing, and transwell assays, respectively. The interactions between LINC00324 and miR-3200-5p and between miR-3200-5p and BCAT1 were determined by a dual-luciferase reporter and/or RNA pull-down assay.

RESULTS

The expression of LINC00324 was upregulated in GC cells and tissues, but miR-3200-5p was downregulated. Silencing of LINC00324 inhibited the proliferation, migration, and invasion of GC cells. LINC00324 directly targeted miR-3200-5p, and miR-3200-5p directly targeted BCAT1. si-LINC00324 negatively regulated BCAT1 expression via binding to miR-3200-5p. Furthermore, silencing of LINC00324 reversed the promoting effects of BCAT1 on the proliferation, migration, and invasion of GC cells.

CONCLUSION

Silencing of LINC00324 inhibited the proliferation, migration, and invasion of GC cells through regulating the miR-3200-5p/BCAT1 axis.

Long Non-Coding RNA BLACAT1 Promotes the Tumorigenesis of Gastric Cancer by Sponging microRNA-149-5p and Targeting KIF2A

Objective

Gastric cancer (GC) is a gastrointestinal tumor. This study is aimed to explore the regulatory mechanism of long non-coding RNA BLACAT1 (BLACAT1)/microRNA-149-5p (miR-149-5p)/KIF2A cascade on GC.

Methods

The expression of BLACAT1, miR-149-5p and KIF2A in GC was detected by qRT-PCR. The proliferation, migration and invasion of GC cells in vitro were analyzed by MTT, wound-healing and transwell assay, respectively. The xenograft tumor model was constructed in nude mice to confirm the inhibition effect of BLACAT1 knockdown on GC in vivo. Then, dual-luciferase reporter assay was used to detect the interactions among BLACAT1, miR-149-5p and KIF2A. Western blot assay was performed to determine the protein expression of KIF2A.

Results

The expression of BLACAT1 and KIF2A was up-regulated in GC, but miR-149-5p expression was down-regulated. Silencing of BLACAT1 retarded the proliferation, migration and invasion of GC cells in vitro and the growth of tumor xenograft in vivo. Moreover, BLACAT1 acted as the molecular sponge of miR-149-5p to up-regulate KIF2A expression. At last, feedback experiments suggested that BLACAT1 accelerated the proliferation, migration and invasion of GC cells by regulating miR-149-5p/KIF2A axis.

Conclusion

BLACAT1 facilitated the tumorigenesis of GC through regulating miR-149-5p/KIF2A axis, which indicated BLACAT1/miR-149-5p/KIF2A cascade may be a new therapeutic target.

Molecular mechanisms of long non-coding RNAs in anaplastic thyroid cancer: a systematic review

BACKGROUND

anaplastic thyroid cancer (ATC) is one of the most lethal and aggressive cancers. Evidence has shown that the tumorigenesis of ATC is a multistep process involving the accumulation of genetic and epigenetic changes. Several studies have suggested that long non-coding RNAs (lncRNAs) may play an important role in the development and progression of ATC. In this article, we have collected the published reports about the role of lncRNAs in ATC.

METHODS

"Scopus", "Web of Science", "PubMed", "Embase", etc. were systematically searched for articles published since 1990 to 2020 in English language, using the predefined keywords.

RESULTS

961 papers were reviewed and finally 33 papers which fulfilled the inclusion and exclusion criteria were selected. Based on this systematic review, among a lot of evidences on examining the function of lncRNAs in thyroid cancer, there are only a small number of studies about the role of lncRNAs and their molecular mechanisms in the pathogenesis of ATC.

CONCLUSIONS

lncRNAs play a crucial role in regulation of different processes involved in the development and progression of ATC. Currently, just a few lncRNAs have been identified in ATC that may serve as prognosis markers such as GAS5, MIR22HG, and CASC2. Also, because of the dysregulation of Klhl14-AS, HOTAIRM1, and PCA3 during ATC development and progression, they may act as therapeutic targets. However, for most lncRNAs, only a single experiment has evaluated the expression profile in ATC tissues/cells. Therefore, further functional studies and expression profiling is needed to resolve this limitation and identify novel and valid biomarkers.

ST8SIA6-AS1 promotes hepatocellular carcinoma by absorbing miR-5195-3p to regulate HOXB6

BACKGROUND

Deemed as a member of malignant tumors, hepatocellular carcinoma (HCC) has been characterized as a lethal disease with high morbidity and mortality. It has been widely accepted that long noncoding RNAs (lncRNAs) play a big part in the complicated biologic processes of cancer.

AIM OF THE STUDY

The purpose of the study is to figure out the role and molecular regulation mechanism of ST8SIA6-AS1 in HCC.

METHODS

The role of ST8SIA6-AS1 in HCC was validated by RT-qPCR, colony formation, ki-67 detection, TUNEL, JC-1 detection, wound healing and transwell-invasion assays, furthermore, the binding ability between ST8SIA6-AS1/HOXB6 and miR-5195-3p were confirmed by RNA pull down and luciferase reporter assays. Besides, the regulatory mechanism of ST8SIA6-AS1 to HOXB6/miR-5195-3p was measured by RT-qPCR and western blot assays.

RESULTS

We measured that ST8SIA6-AS1 was highly expressed in HCC cell lines. Then knockdown of it suppressed cell proliferation, migration and migration but activated cell apoptosis in HCC. Furthermore, ST8SIA6-AS1 could bind with miR-5195-3p and negatively regulated its expression in HCC. Subsequently, it confirmed that HOXB6 was target gene of miR-5195-3p and positively modulated by ST8SIA6-AS1 in HCC. Finally, we verified that miR-5195-3p deficiency or HOXB6 upregulation countervailed the repressing effects of ST8SIA6-AS1 depletion on HCC progression.

CONCLUSIONS

To sum up, ST8SIA6-AS1 promotes HCC progression by absorbing miR-5195-3p to regulate HOXB6, which might provide some worthy suggestions to research the development process of HCC.

SNP rs12982687 affects binding capacity of lncRNA UCA1 with miR-873-5p: involvement in smoking-triggered colorectal cancer progression

BACKGROUND

This investigation was arranged to elucidate whether single nucleotide polymorphisms (SNPs) of lncRNA UCA1 was implicated in elevating colorectal cancer (CRC) risk by interacting with environmental exposures.

METHODS

LncRNASNP database was firstly adopted to predict SNPs that possibly affected binding of UCA1 with miRNAs and then the interactive effect of SNPs and environmental exposure on CRC risk was evaluated by recurring to type 2 gene-environment interactions (GEI) model. Besides, MTT assay, colony formation assay, transwell assay and wound healing assay were performed to assess the activity of CRC cell lines which carried distinct genotypes of specific SNPs. The impact of nicotine on activity of CRC cells was also appraised.

RESULTS

SNP rs12982687 of UCA1 intervened in the binding capacity of UCA1 with several miRNAs, especially miR-873-5p. MiRNAs regulated by UCA1, as predicted by mirPath software, shared genes that were enriched in HIF1 signaling pathway. Moreover, homozygote TT of rs12982687 reduced CRC risk among smokers, and CRC cells that carried rs12982687 (CC) displayed strong migration and invasion. By contrast, miR-873-5p mimic, which reduced UCA1 expression, delayed metastasis of CRC cells (all P < 0.05). Additionally, nicotine not merely elevated UCA1 and HIF-1α expressions in CRC cells, but also facilitated proliferation and metastasis of CRC cells (P < 0.05).

CONCLUSIONS

SNP rs12982687 was involved in smoking-triggered CRC progression, given its influence on UCA1's binding with miR-873-5p and HIF-1 signaling.

Biological and clinical relevance of metastasis-associated long noncoding RNAs in esophageal squamous cell carcinoma: A systematic review

Esophageal squamous cell carcinoma (ESCC) is a foremost cancer-related death worldwide owing to rapid metastasis and poor prognosis. Metastasis, as the most important reason for death, is biologically a multifaceted process involving a range of cell signaling pathways. Long noncoding RNAs (lncRNAs), as transcriptional regulators, can regulate numerous genomic processes and cellular processes such as cell proliferation, migration, and invasion. LncRNAs have also been shown to involve in/regulate the cancer metastasis-related signaling pathways. Hence, they have increasingly been brought to international attention in molecular oncology research. A number of researchers have attempted to reveal the biological and clinical relevance of lncRNAs in ESCC tumourigenesis and metastasis. The aberrant expression of these molecules in ESCC has regularly been reported to involve in various cellular processes and clinical features, including diagnosis, prognosis, and therapeutic responses. Here, we especially consider the pathways in which lncRNAs act as metastasis-mediated effectors, mainly by interacting with epithelial-mesenchymal transition-associated factors. We review the biological roles of lncRNAs through involving in ESCC metastasis as well as the clinical significance of the metastasis-related lncRNAs in cancer diagnosis and prognosis.

LncRNA SNHG1 Regulates the Progression of Esophageal Squamous Cell Cancer by the miR-204/HOXC8 Axis

Objective

Long noncoding RNA small nucleolar RNA host gene 1 (SNHG1) has been reported to be aberrantly expressed and plays an important role in human cancers, including esophageal squamous cell cancer. However, the regulatory mechanism underlying SNHG1 in the progression of esophageal squamous cell cancer is poorly defined.

Materials and Methods

Fifty-three esophageal squamous cell cancer patients were recruited and overall survival was analyzed. EC9706 and KYSE150 cells were cultured for study in vitro. The expression levels of SNHG1, microRNA (miR)-204 and homeobox c8 (HOXC8) were detected by quantitative real-time polymerase chain reaction and Western blot. Cell cycle distribution, apoptosis, migration and invasion were determined by flow cytometry and transwell assays, respectively. The target interaction among SNHG1, miR-204 and HOXC8 was validated by luciferase reporter assay and RNA immunoprecipitation. Xenograft model was established to investigate the role of SNHG1 in vivo.

Results

High expression of SNHG1 was exhibited in esophageal squamous cell cancer and indicated poor outcomes of patients. SNHG1 silence led to cell cycle arrest at G0-G1 phase, inhibition of migration and invasion and increase of apoptosis. miR-204 was validated to sponge by SNHG1 and target HOXC8 in esophageal squamous cell cancer cells. miR-204 knockdown or HOXC8 restoration reversed the inhibitive role of SNHG1 silence in the progression of esophageal squamous cell cancer cells. Furthermore, inhibiting SNHG1 decreased xenograft tumor growth by regulating miR-204 and HOXC8.

Conclusion

SNHG1 knockdown suppresses migration and invasion but induces apoptosis of esophageal squamous cell cancer cells by increasing miR-204 and decreasing HOXC8.

Silencing of lncRNA UCA1 curbs proliferation and accelerates apoptosis by repressing SIRT1 signals by targeting miR-204 in pediatric AML

The long noncoding RNA urothelial carcinoma-associated 1 (UCA1) has been reported to sustain the proliferation of acute myeloid leukemia (AML) cells through downregulating cell cycle regulators p27^kip1 . Yet, the foundational mechanism of UCA1 in AML pathologies remains unclear. Herein, we found an escalation of UCA1 expression and suppression of miR-204 expression in pediatric AML patients and cells. UCA1 silencing suppressed cell proliferative abilities, promoted apoptotic rates, decreased Ki67, and increased cleaved caspase-3 in AML cells. Moreover, UCA1 sponged miR-204 and suppressed its expression. UCA1 overexpression inversed the miR-204 suppressed proliferation and promoted apoptosis. UCA1 also boosted the expression of SIRT1, a miR-204 target, via the sponging interaction. Furthermore, miR-204 inhibited inducible nitric oxide synthase and cyclooxygenase-2 expression, while UCA1 overexpression inversed the inhibitory effects in AML cells. Our findings concluded that UCA1 downregulation repressed cell proliferation and promoted apoptosis through inactivating SIRT1 signals by upregulating miR-204 in pediatric AML.

LINC00511 accelerated the process of gastric cancer by targeting miR-625-5p/NFIX axis

Background

Gastric cancer (GC) is a common-sighted cancer which is hard to cure over the world. Substantial researches revealed that long non-coding RNAs (lncRNAs) were fundamental regulators in the process of cancers. Nevertheless, the biological function of LINC00511 and how LINC00511 was involved in the regulatory system in GC remained unclear.

Methods

RIP assays and luciferase reporter assays were performed to illustrate combination between LINC00511 and miR-625-5p. Loss-of-function assays were applied for identifying LINC00511 function in GC.

Results

In our study, LINC00511 was discovered significantly high in expression in GC tissues and cell lines. Moreover, LINC00511 showed a strong expression in I/II and III/IV stage. Knockdown of LINC00511 could inhibit the cell proliferation while enhanced cell apoptosis rate in GC. We used nuclear–cytoplasmic fractionation to judge the subcellular localization of LINC00511. Furthermore, miR-625-5p was found to have binding sites for LINC00511 and negatively regulated by LINC00511. Overexpression of miR-625-5p repressed the course of GC. And knockdown of miR-625-5p could recover the effects of LINC00511 silence. Besides, NFIX was discovered as a downstream target of miR-625-5p and overexpression of NFIX could offset the influence of LINC00511 silence. The results of vivo studies manifested that down-regulation of LINC00511 could reduce the Ki67 expression and NFIX while lifted the expression of miR-625-5p.

Conclusion

Overall, the results from our study demonstrated that LINC00511 could function as a tumor promoter by targeting miR-625-5p NFIX axis, suggesting LINC00511 could be considered as a target for GC treatment.

Long Noncoding RNA UCA1 Overexpression Is Associated with Poor Prognosis in Digestive System Malignancies: A Meta-analysis

Long noncoding RNA (lncRNA) urothelial carcinoma associated 1 (UCA1) has been reported to be highly expressed in many kinds of cancers. This meta-analysis summarized its potential prognostic value in digestive system malignancies. A meta-analysis was performed through a comprehensive search in PubMed, EMBASE, the Cochrane Library, Web of Science and Chinese National Knowledge Infrastructure (CNKI) for suitable articles on the prognostic impact of UCA1 in digestive system malignancies from inception to June 27, 2019. Pooled hazard ratios (HRs) with 95% confidence interval (95%CI) were calculated to summarize the effect. Sixteen studies were included in the study, with a total of 1504 patients. A significant association was observed between UCA1 abundance and poor overall survival (OS), and shorter disease-free survival (DFS) for patients with digestive system malignancies, with pooled HR of 2.07 (95%CI: 1.74-2.47), and of 2.50 (95%CI: 1.62-3.86). Subgroup analysis and sensitivity analysis suggested the reliability of our findings. It is suggested that UCA1 abundance may serve as a reliable predictive factor for poor prognosis in patients with digestive system malignancies.

UCA1 long non-coding RNA: An update on its roles in malignant behavior of cancers

The lncRNA urothelial carcinoma-associated 1 (UCA1) is a 1.4 kb long transcript which has been firstly recognized in human bladder cancer cell line. Subsequent studies revealed its over-expression in a wide array of human cancer cell lines and patients' samples. In addition to conferring malignant phenotype to cells, it enhances resistance to conventional anti-cancer drugs. Moreover, transcript levels of this lncRNA have been regarded as diagnostic markers in several cancer types including gastric, bladder and liver cancers. The underlying mechanism of its participation in carcinogenesis has been identified in some cancer types. Sponging tumor suppressor miRNAs, interacting with cancer-promoting signaling pathways and enhancing cell cycle progression are among these mechanisms. Although few studies have shown anti-carcinogenic properties for this lncRNA, the bulk of evidence supports its oncogenic roles. In the current study, we have reviewed the current literature on the role of UCA1 in the carcinogenic process based on the results of in vitro studies, investigations in animal models and assessment of UCA1 expression in clinical samples.

LncRNA UCA1 affects epithelial-mesenchymal transition, invasion, migration and apoptosis of nasopharyngeal carcinoma cells

Objective: In this study, long non-coding RNA urothelial carcinoma associated 1 (lncRNA UCA1) in nasopharyngeal carcinoma (NPC) and its effect on the malignant phenotype of NPC cells was investigated. Methods: Initially, the expression of UCA1 in NPC tissues and cells was detected. NPC cell line that with highest expression of UCA1 was selected for subsequent cell function test. A series of experiments were used to detect proliferation, colony formation, cell cycle distribution, apoptosis, invasion and migration of NPC cells with the interference of UCA1 expression. Western blot analysis was carried out to detect the expression of E-cadherin and vimentin for verifying the effect of UCA1 on epithelial mesenchymal transition (EMT). Results: The expression of UCA1 was found to be upregulated in NPC tissues and cells. The expression of UCA1 in stage Ⅲ + IV of NPC tissues and in patients with lymph node metastasis was significantly higher than that in patients at stage Ⅰ + Ⅱ and in patients without lymph node metastasis. Inhibition of UCA1 repressed proliferation, EMT, colony formation, invasion and migration while stimulating apoptosis of NPC cells. Conclusion: Our study suggests that UCA1 expression was overexpressed in NPC. Additionally, UCA1 suppression could inhibit proliferation, EMT, invasion and migration, and promote apoptosis of NPC cells.

Downregulated lncRNA UCA1 acts as ceRNA to adsorb microRNA-498 to repress proliferation, invasion and epithelial mesenchymal transition of esophageal cancer cells by decreasing ZEB2 expression

Objective: Esophageal cancer (EC) is one of the most general malignant tumors in humans. There were few studies researching the connections between lncRNA UCA1 and EC. This study is to research the effect of lncRNA UCA1 adsorbing microRNA-498 (miR-498) as a ceRNA to regulate ZEB2 expression on epithelial mesenchymal transition (EMT), invasion and migration of EC cells. Methods: UCA1, miR-498 and ZEB2 expression in EC tissues and cells was detected by RT-qPCR or western blot analysis. EC cells were transfected with siRNA-UCA1, miR-498 mimics or their controls to determine cell colony, proliferation, cycle distribution, apoptosis, migration and invasion by colony formation assay, CCK-8 assay, flow cytometry, and Transwell assay, respectively. The protein expression of PCNA, c-Myc, E-cadherin, N-cadherin, MMP-2 and MMP-9 was detected by Western blot analysis. The growth rate and weight of transplanted tumor in nude mice were observed. Results: There were overly expressed UCA1 and ZEB2 and lowly expressed miR-498 in EC tissues and cells. LncRNA UCA1 acted as ceRNA to inhibit miR-498 expression and thereby increasing ZEB2 expression. With down-regulated UCA1 and up-regulated miR-498, ZEB2 expression, cell proliferation, colony formation, invasion, migration ability, EMT, tumor growth rate and weight in nude mice were apparently reduced. Conclusion: This study demonstrates that inhibited UCA1 up-regulated miR-498 and down-regulated ZEB2, thereby repressing proliferation activity, invasion, migration, and EMT of EC cells.

Long noncoding RNA HAGLR acts as a microRNA-143-5p sponge to regulate epithelial-mesenchymal transition and metastatic potential in esophageal cancer by regulating LAMP3

Homeobox D gene cluster antisense growth-associated long noncoding RNA (HAGLR) functions as a crucial regulator in the progression and development of human cancers. We analyzed effects of HAGLR, microRNA (miR)-143-5p and lysosome-associated membrane glycoprotein (LAMP)3 on esophageal cancer (EC) and the related mechanisms. Microarray analysis was used to screen out EC-related genes and the regulation network among HAGLR, miR-143-5p, and LAMP3. The regulatory mechanisms of HAGLR and miR-143-5p in EC were analyzed following the treatment of miR-143-5p mimic, miR-143-5p inhibitor, HAGLR vector, or small interfering RNA against HAGLR in EC cells. The expression of N-cadherin, vimentin, Twist1, Snail1, and E-cadherin as well as the abilities of cell proliferation, invasion, and migration were measured. The effects of the HAGLR/miR-143-5p/LAMP3 axis were determined in vivo by assessing tumor formation in nude mice. The expression of HAGLR and LAMP3 was increased, whereas that of miR-143-5p was diminished in EC tissues and cells. HAGLR could competitively bind to miR-143-5p, and miR-143-5p targeted LAMP3. Down-regulated HAGLR or up-regulated miR-143-5p increased E-cadherin expression and significantly diminished expression of LAMP3, N-cadherin, vimentin, Twist1, and Snail1. Moreover, down-regulated HAGLR inhibited cell proliferation, invasion, migration, epithelial-mesenchymal transition (EMT), and tumor growth. Moreover, down-regulation of HAGLR inhibited LAMP3 expression by sponging miR-143-5p, thereby suppressing the progression of EC. Taken together, our results suggest HAGLR acts as a competing endogenous RNA of miR-143-5p to increase the expression of LAMP3, thus promoting EMT, proliferation, invasion, and migration in EC cells.-Yang, C., Shen, S., Zheng, X., Ye, K., Sun, Y., Lu, Y., Ge, H. Long noncoding RNA HAGLR acts as a microRNA-143-5p sponge to regulate epithelial-mesenchymal transition and metastatic potential in esophageal cancer by regulating LAMP3.

The prognostic value and mechanisms of lncRNA UCA1 in human cancer

Long noncoding RNAs (lncRNAs), longer than 200 nucleotides in length, play important roles in the development and progression of various cancers. An increasing number of studies have revealed that lncRNAs function as potential oncogenes or tumor suppressors to influence biological processes, such as cell growth, invasion, migration and apoptosis. Urothelial carcinoma associated 1 (UCA1), an oncogenic lncRNA, was first found in bladder cancer and highly expressed in multiple cancers, including gastric cancer, colorectal cancer, lung cancer and breast cancer. UCA1 promotes tumorigenesis mainly via binding to tumor-suppressive microRNAs (miRNAs), activating several pivotal signaling pathways and alteration of epigenetic and transcriptional regulation. In addition, high expression of UCA1 is related to poor clinicopathological features especially for shorter overall survival, suggesting that UCA1 might be regarded as a prognosis biomarker in human cancers. In the present review, we summarized current studies on UCA1 to explore its prognostic value and underlying regulation mechanisms in the development of multiple cancers in order to provide a glimmer of hope for the prevention and treatment of malignant tumors.

Down-regulation of long non-coding RNA HOTAIR inhibits invasion and migration of oesophageal cancer cells via up-regulation of microRNA-204

Oesophageal cancer is a progressive tumour with high mortality. However, therapies aimed at treating oesophageal cancer remain relatively limited. Accumulating studies have highlighted long non‐coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR), microRNA‐204 (miR‐204) and homeobox C8 (HOXC8) in the progression of oesophageal cancer. Herein, we tried to demonstrate the function of HOTAIR, miR‐204 and HOXC8 in oesophageal cancer and their relationship. Differentially expressed genes involved in oesophageal cancer were identified. The endogenous expression of HOTAIR and miR‐204 in oesophageal cancer cell lines was altered to elucidate their effects and to identify the interaction among HOTAIR, miR‐204 and HOXC8. We also explored the underlying regulatory mechanisms of HOTAIR and miR‐204 with siRNA against HOTAIR, miR‐204 mimic or miR‐204 inhibitor. Cell proliferation, migration, invasion and apoptosis were subsequently detected. Xenograft in nude mice was induced to evaluate tumourigenicity. miR‐204 was down‐regulated, while HOTAIR and HOXC8 were up‐regulated in the oesophageal cancer tissues. HOTAIR could competitively bind to miR‐204 and miR‐204 could further target HOXC8. The oesophageal cancer cells treated with si‐HOTAIR or miR‐204 mimic exhibited decreased expression levels of HOXC8, Vimentin and MMP‐9, but increased E‐cadherin level. Silenced HOTAIR or elevated miR‐204 inhibited proliferation, migration and invasion, along with stimulated apoptosis of oesophageal cancer cells. In summary, our results show that lncRNA HOTAIR could specifically bind to miR‐204 as a competing endogenous RNA and regulate miR‐204 and HOXC8. Hence, down‐regulation of HOTAIR could inhibit progression of oesophageal cancer, indicating a novel target for oesophageal cancer treatment.

Crosstalk between the lncRNA UCA1 and microRNAs in cancer

Long non-coding RNAs (lncRNAs) are a major subset of highly conserved non-coding RNAs (ncRNAs) that consist of at least 200 nucleotides and have limited protein-coding potential. Cumulative data have shown that lncRNAs are deregulated in many types of cancer and may control pathophysiological processes of cancer at various levels, including transcription, post-transcription and translation. Recently, lncRNAs have been demonstrated to interact with microRNAs (miRNAs), another major subset of ncRNAs, which regulate physiological and pathological processes by inhibiting target mRNA translation or promoting mRNA degradation. The lncRNA urothelial carcinoma-associated 1 (UCA1) has recently gained much attention as it is overexpressed in many types of cancer and is involved in carcinogenesis. Here, we review the crosstalk between UCA1 and miRNAs during the pathogenesis of cancer, with a focus on cancer-cell proliferation, invasion, drug resistance, and metabolism.

LINC00922 Accelerates the Proliferation, Migration and Invasion of Lung Cancer Via the miRNA-204/CXCR4 Axis

BACKGROUND The aim of this study was to clarify the potential function of LINC00922 in regulating the progression of lung cancer and its underling mechanism. MATERIAL AND METHODS Relative levels of LINC00922 in lung cancer tissues and cell lines was determined by quantitative polymerase chain reaction. Correlation between LINC00922 levels and pathological indexes of lung cancer patients was analyzed through the chi-square test. Subsequently, regulatory effects of LINC00922 on the proliferative, migratory, and invasive capacities of PC9 and A549 cells were evaluated. Western blot was conducted to determine the role of LINC00922 in mediating protein levels of CXCR4, E-cadherin, and vimentin. Through dual-luciferase reporter gene assay and functional experiments, the potential function of LINC00922/miRNA-204/CXCR4 regulatory loop in mediating the progression of lung cancer was explored. RESULTS LINC00922 was highly expressed in lung cancer and correlated to the poor prognosis of lung cancer patients. Overexpression of LINC00922 accelerated PC9 and A549 cells to proliferate, migrate, and invade. CXCR4 was upregulated in lung cancer tissues and cells, which promoted lung cancer cells to migrate and invade. LINC00922 regulated the level of CXCR4 and directly bound to miRNA-204/CXCR4. LINC00922 mediated the cellular behaviors of lung cancer cells via targeting the miRNA-204/CXCR4 axis. CONCLUSIONS LINC00922 was upregulated in lung cancer, and accelerated lung cancer cells to proliferate, migrate, and invade via targeting the miRNA-204/CXCR4 axis.

SOX4: Epigenetic regulation and role in tumorigenesis

Sex-determining region Y-related (SRY) high-mobility group box 4 (SOX4) is a member of the group C subfamily of SOX transcription factors and promotes tumorigenesis by endowing cancer cells with survival, migratory, and invasive capacities. Emerging evidence has highlighted an unequivocal role for this transcription factor in mediating various signaling pathways involved in tumorigenesis, epithelial-to-mesenchymal transition (EMT), and tumor progression. During the last decade, numerous studies have highlighted the epigenetic interplay between SOX4-targeting microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and SOX4 and the subsequent modulation of tumorigenesis, invasion and metastasis. In this review, we summarize the current state of knowledge about the role of SOX4 in cancer development and progression, the epigenetic regulation of SOX4, and the potential utilization of SOX4 as a diagnostic and prognostic biomarker and its depletion as a therapeutic target.

Matrix Hyaluronan-CD44 Interaction Activates MicroRNA and LncRNA Signaling Associated With Chemoresistance, Invasion, and Tumor Progression

Tumor malignancies involve cancer cell growth, issue invasion, metastasis and often drug resistance. A great deal of effort has been placed on searching for unique molecule(s) overexpressed in cancer cells that correlate(s) with tumor cell-specific behaviors. Hyaluronan (HA), one of the major ECM (extracellular matrix) components have been identified as a physiological ligand for surface CD44 isoforms which are frequently overexpressed in malignant tumor cells during cancer progression. The binding interaction between HA and CD44 isoforms often stimulates aberrant cellular signaling processes and appears to be responsible for the induction of multiple oncogenic events required for cancer-specific phenotypes and behaviors. In recent years, both microRNAs (miRNAs) (with ~20–25 nucleotides) and long non-coding RNAs (lncRNAs) (with ~200 nucleotides) have been found to be abnormally expressed in cancer cells and actively participate in numerous oncogenic signaling events needed for tumor cell-specific functions. In this review, I plan to place a special emphasis on HA/CD44-induced signaling pathways and the presence of several novel miRNAs (e.g., miR-10b/miR-302/miR-21) and lncRNAs (e.g., UCA1) together with their target functions (e.g., tumor cell migration, invasion, and chemoresistance) during cancer development and progression. I believe that important information can be obtained from these studies on HA/CD44-activated miRNAs and lncRNA that may be very valuable for the future development of innovative therapeutic drugs for the treatment of matrix HA/CD44-mediated cancers.

Functional analysis of lncRNAs based on competitive endogenous RNA in tongue squamous cell carcinoma

Backround

Tongue squamous cell carcinoma (TSCC) is the most common malignant tumor in the oral cavity. An increasing number of studies have suggested that long noncoding RNA (lncRNA) plays an important role in the biological process of disease and is closely related to the occurrence and development of disease, including TSCC. Although many lncRNAs have been discovered, there remains a lack of research on the function and mechanism of lncRNAs. To better understand the clinical role and biological function of lncRNAs in TSCC, we conducted this study.

Methods

In this study, 162 tongue samples, including 147 TSCC samples and 15 normal control samples, were investigated and downloaded from The Cancer Genome Atlas (TCGA). We constructed a competitive endogenous RNA (ceRNA) regulatory network. Then, we investigated two lncRNAs as key lncRNAs using Kaplan-Meier curve analysis and constructed a key lncRNA-miRNA-mRNA subnetwork. Furthermore, gene set enrichment analysis (GSEA) was carried out on mRNAs in the subnetwork after multivariate survival analysis of the Cox proportional hazards regression model.

Results

The ceRNA regulatory network consists of six differentially expressed miRNAs (DEmiRNAs), 29 differentially expressed lncRNAs (DElncRNAs) and six differentially expressed mRNAs (DEmRNAs). Kaplan-Meier curve analysis of lncRNAs in the TSCC ceRNA regulatory network showed that only two lncRNAs, including LINC00261 and PART1, are correlated with the total survival time of TSCC patients. After we constructed the key lncRNA-miRNA -RNA sub network, the GSEA results showed that key lncRNA are mainly related to cytokines and the immune system. High expression levels of LINC00261 indicate a poor prognosis, while a high expression level of PART1 indicates a better prognosis.

LncRNA H19 promotes epithelial mesenchymal transition and metastasis of esophageal cancer via STAT3/EZH2 axis

BACKGROUND

Long non-coding RNA H19 (lncRNA H19) has been widely reported in esophageal cancer (EC), and previous study had found that lncRNAH19 was up-regulated in EC and promoted cell proliferation and metastasis. However, the mechanism still needs further studied.

METHODS

Levels of lncRNA H19 were analyzed by qRT-PCR in matched samples from 30 patients. Expression levels of lncRNA H19, let-7, STAT3 and EZH2 were additionally identified by qRT-PCR and western blotting in five EC cell lines. The effects of lncRNA H19 on cell proliferation, migration, invasion and apoptosis in cell lines were performed by MTT assay, colony formation assay, Transwell assay and flow cytometry in vitro, and tumor formation was detected by xenograft nude mice model in vivo. The expression level of STAT3, EZH2, β-catenin, and EMT and metastasis related molecules such as E-cadherin, N-cadherin, Snail-1 and MMP-9 was assessed by qRT-PCR and western blotting. Finally, luciferase reporter assay and RIP assay were used to verify the interaction between lncRNA H19 and let-7c, and their subsequent regulation of STAT3.

RESULTS

Knockdown of lncRNA H19 repressed cell proliferation, migration and invasion as well as EMT and metastasis via STAT3-EZH2-β-catenin pathway, while lncRNA H19 regulated STAT3 negatively regulated let-7c in EC cell lines.

CONCLUSIONS

lncRNA H19 facilitates EMT and metastasis of EC through let-7c/STAT3/EZH2/β-catenin axis.

lncRNA CADM1-AS1 inhibits cell-cycle progression and invasion via PTEN/AKT/GSK-3β axis in hepatocellular carcinoma

Purpose: CADM1-AS1 (cell adhesion molecule 1 antisense RNA 1, long non-coding RNA), was firstly characterized in renal clear cell carcinoma, and exhibits a tumor suppressor role. However, its clinical relevance and exact effects in hepatocellular carcinoma (HCC) remain unknown. Therefore, in this study, we aimed to assess the clinical significance and function of CADM1-AS1 in HCC. Methods: We detected CADM1-AS1 expression in liver cancer tissue samples and cell lines, and analyzed the association between CADM1-AS1 expression and clinical parameters in 90 liver cancer patients. Moreover, we conducted gain-of-function and loss-of-function studies in liver cancer cell to explore the biological function and molecular mechanism of CADM1-AS1. Results: CADM1-AS1 expression was reduced in HCC. Clinical data showed that this downregulation was associated with advanced tumor stage, high TNM stage and reduced survival in HCC patients. CADM1-AS1 overexpression inhibited HCC cells proliferation, migration and invasion, while inducing G0/G1 phase arrest. Meanwhile, we revealed that CADM1-AS1 inhibited the phosphorylation of AKT and GSK-3β. Furthermore, our study showed that CADM1-AS1 decreased the cell cycle associated proteins expression of cyclinD, cyclinE, CDK2 CDK4, CDK6, and enhanced the levels of p15, p21 and p27. More importantly, SC79, a specific activator for AKT;, apparently attenuated the effects of CADM1-AS1 on above cell-cycle associated proteins, confirming that CADM1-AS1 inhibited cell cycles through the AKT signaling pathway. And we also found the CADM1-AS1 has antitumor effect in vivo by a xenograft HCC mouse model. In conclusion, the present findings show that the CADM1-AS1 inhibits proliferation of HCC by inhibiting AKT/GSK-3β signaling pathway, then upregulate p15, p21, p27 expression and downregulate cyclin, CDK expression to inhibit the G0/G1 to S phase transition both in vitro and in vivo. Conclusion: CADM1-AS1 functions as a tumor-suppressive lncRNA. This study reveals a molecular pathway involving PTEN/AKT/GSK-3β which regulates HCC cell-cycle progression.

Long noncoding RNA UCA1 as a novel biomarker of lymph node metastasis and prognosis in human cancer: a meta-analysis

Background: Urothelial carcinoma associated 1 (UCA1), a novel long noncoding RNA (lncRNA) which is first discovered in 2006 in human bladder cancer and has become a hot spot in recent years. UCA1 has been demonstrated correlated with clinical outcomes in various cancers. However, the results from each study are insufficient and not completely consistent. Therefore, we perform a systematic meta-analysis to evaluate the value for a feasible biomarker for metastasis and prognosis of cancer. Methods: Relevant English literatures were searched in PubMed, Cochrane Library, Web of science, Embase databases and Chinese literatures were searched in Chinese National Knowledge Infrastructure Wanfang from inception up to 17 April 2018. The pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) using random/fixed-effect were used to identify the relationship between UCA1 and lymph node metastasis (LNM) or overall survival (OS) of cancer patients. Subgroup analysis and sensitivity analysis were performed. The current meta-analysis was performed using Review Manager 5.3 and Stata 12.0 software. Results: A total of 3411 patients from 38 studies were finally included. Patients who with high UCA1 expression suffered from an increased risk of LNM (OR = 2.50; 95% CI: 1.93–3.25). UCA1 was also significantly associated with OS (HR = 2.05; 95% CI: 1.77–2.38). Subgroup analyses across several different variables also showed the similar results in LNM and OS of cancer patients. Conclusion: High expression of UCA1 was linked with poor clinical outcome. UCA1 can serve as a potential molecular marker for metastasis and prognosis in different types of cancers.

Characteristics of the competition among RNAs for the binding of shared miRNAs

Competing endogenous RNAs (ceRNAs) are RNAs that share common miRNA binding sites and compete with each other for the miRNA association at these sites. The observation of this phenomenon in the cells altered the view of the miRNA target RNAs from molecules that are passively controlled by miRNAs to molecules that also modulate the miRNAs activity. In this review, we build a general profile of ceRNAS characteristics in order to facilitate ceRNAs identification by researchers. The information summarized here contains an actualized list of previously reported ceRNAs and classes of RNAs that can participate in this type of interaction, the expression behavior and characteristics of ceRNAs and miRNAs in the context of competition, the influence of the shared MREs/miRNAs numbers and the miRNA binding strength on the competition, reports on competition between RNAs in different subcellular localizations and the concept that ceRNAs may form a huge regulatory network in the cell.

LONG-NONCODING RNAs in gastroesophageal cancers

Despite continuing improvements in multimodal therapies, gastro-esophageal malignances remain widely prevalent in the population and is characterized by poor overall and disease-free survival rates. Due to the lack of understanding about the pathogenesis and absence of reliable markers, gastro-esophageal cancers are associated with delayed diagnosis. The increasing understanding about cancer's molecular landscape in the recent years, offers the possibility of identifying 'targetable' molecular events and in particular facilitates novel treatment strategies and development of biomarkers for early stage diagnosis. At least 98% of our genome is actively transcribed into non-coding RNAs encompassing long non-coding RNAs (lncRNAs) constituted of transcripts longer than 200 nucleotides with no protein-coding capacity. Many studies have demonstrated that lncRNAs are functional genomic elements playing pivotal roles in main oncogenic processes. LncRNA can act at multiple levels developing a complex molecular network that can modulate directly or indirectly the expression of genes involved in tumorigenesis. In this review, we focus on lncRNAs as emerging players in gastro-esophageal carcinogenesis and critically assess their potential as reliable noninvasive biomarkers and in next generation targeted therapies.