miRNA-448 inhibits cell growth by targeting BCL-2 in hepatocellular carcinoma

Molecular Mechanisms in Tumorigenesis of Hepatocellular Carcinoma and in Target Treatments-An Overview

Hepatocellular carcinoma is the most common primary malignancy of the liver, with hepatocellular differentiation. It is ranked sixth among the most common cancers worldwide and is the third leading cause of cancer-related deaths. The most important etiological factors discussed here are viral infection (HBV, HCV), exposure to aflatoxin B1, metabolic syndrome, and obesity (as an independent factor). Directly or indirectly, they induce chromosomal aberrations, mutations, and epigenetic changes in specific genes involved in intracellular signaling pathways, responsible for synthesis of growth factors, cell proliferation, differentiation, survival, the metastasis process (including the epithelial-mesenchymal transition and the expression of adhesion molecules), and angiogenesis. All these disrupted molecular mechanisms contribute to hepatocarcinogenesis. Furthermore, equally important is the interaction between tumor cells and the components of the tumor microenvironment: inflammatory cells and macrophages-predominantly with a pro-tumoral role-hepatic stellate cells, tumor-associated fibroblasts, cancer stem cells, extracellular vesicles, and the extracellular matrix. In this paper, we reviewed the molecular biology of hepatocellular carcinoma and the intricate mechanisms involved in hepatocarcinogenesis, and we highlighted how certain signaling pathways can be pharmacologically influenced at various levels with specific molecules. Additionally, we mentioned several examples of recent clinical trials and briefly described the current treatment protocol according to the NCCN guidelines.

Mitochondrial-mediated nuclear remodeling and macrophage polarizations: A key switch from liver fibrosis to HCC progression

Liver fibrosis is a significant health burden worldwide and has emerged as the leading cause of Hepatocellular carcinoma (HCC) incidence. Mitochondria are the dynamic organelles that regulate the differentiation, survival, and polarization of macrophages. Nuclear-DNA-associated proteins, micro-RNAs, as well as macrophage polarization are essential for maintaining intracellular and extra-cellular homeostasis in the liver parenchyma. Dysregulated mitochondrial coding genes (ETS complexes I, II, III, IV, and V), non-coding RNAs (mitomiRs), and nuclear alteration lead to the production of reactive oxygen species (ROS) and inflammation which are implicated in the transition of liver fibrosis into HCC. Recent findings indicated the protecting effect of E74-like factor 3/peroxisome proliferator-activated receptor-γ (Elf-3/PPAR-γ). HDAR-y inhibits the deacetylation of PPAR-y and maintains the PPAR-y pathway. Elf-3 plays a tumor suppressive role through epithelial-mesenchymal transition-related gene and zinc finger E-box binding homeobox 2 (ZEB-2) domain. Additionally, the development of HCC includes the PI3K/Akt/mTOR and transforming Growth Factor β (TGF-β) pathway that promotes the Epithelial-mesenchymal transition (EMT) through Smad/Snail/Slug signaling cascade. In contrast, the TLR2/NOX2/autophagy axis promotes M2 polarization in HCC. Thus, a thorough understanding of the mitochondrial and nuclear reciprocal relationship related to macrophage polarization could provide new research opportunities concerning diseases with a significant impact on liver parenchyma towards developing liver fibrosis or liver cancer. Moreover, this knowledge can be used to develop new therapeutic strategies to treat liver diseases.

MicroRNAs and their vital role in apoptosis in hepatocellular carcinoma: miRNA-based diagnostic and treatment methods

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies with high invasive and metastatic capability. Although significant advances have been made in the treatment of HCC, the overall survival rate of patients is still low. It is essential to explore accurate biomarkers for early diagnosis and prognosis along with therapeutic procedures to increase the survival rate of these patients. Anticancer therapies can contribute to induce apoptosis for the elimination of cancerous cells. However, dysregulated apoptosis and proliferation signaling pathways lead to treatment resistance, a significant challenge in improving efficient therapies. MiRNAs, short non-coding RNAs, play crucial roles in the progression of HCC, which regulate gene expression through post-transcriptional inhibition and targeting mRNA degradation in cancers. Dysregulated expression of multiple miRNAs is associated with numerous biological processes, including cell proliferation, apoptosis, invasion and metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, and drug resistance in HCC. This review summarizes the role and potential efficacy of miRNAs in promoting and inhibiting cell proliferation and apoptosis in HCC, as well as the role of miRNAs in therapy resistance in HCC.

Circulating miRNAs Expression in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex multifactorial disease that causes increasing morbidity worldwide, and many individuals with ME/CFS symptoms remain undiagnosed due to the lack of diagnostic biomarkers. Its etiology is still unknown, but increasing evidence supports a role of herpesviruses (including HHV-6A and HHV-6B) as potential triggers. Interestingly, the infection by these viruses has been reported to impact the expression of microRNAs (miRNAs), short non-coding RNA sequences which have been suggested to be epigenetic factors modulating ME/CFS pathogenic mechanisms. Notably, the presence of circulating miRNAs in plasma has raised the possibility to use them as valuable biomarkers for distinguishing ME/CFS patients from healthy controls. Thus, this study aimed at determining the role of eight miRNAs, which were selected for their previous association with ME/CFS, as potential circulating biomarkers of the disease. Their presence was quantitatively evaluated in plasma from 40 ME/CFS patients and 20 healthy controls by specific Taqman assays, and the results showed that six out of the eight of the selected miRNAs were differently expressed in patients compared to controls; more specifically, five miRNAs were significantly upregulated (miR-127-3p, miR-142-5p, miR-143-3p, miR-150-5p, and miR-448), and one was downmodulated (miR-140-5p). MiRNA levels directly correlated with disease severity, whereas no significant correlations were observed with the plasma levels of seven pro-inflammatory cytokines or with the presence/load of HHV-6A/6B genome, as judged by specific PCR amplification. The results may open the way for further validation of miRNAs as new potential biomarkers in ME/CFS and increase the knowledge of the complex pathways involved in the ME/CFS development.

Circular RNA circBNC2 facilitates glycolysis and stemness of hepatocellular carcinoma through the miR-217/high mobility group AT-hook 2 (HMGA2) axis

Hepatocellular cancer (HCC) accounts for approximately 90% of primary liver carcinoma and is a significant health threat worldwide. Circular RNA basonuclin 2 (circBNC2) is implicated with the progression of several cancers. However, its roles in carcinogenesis and glycolysis are still unclear in HCC. In this study, the levels of circBNC2 and high mobility group AT-hook 2 (HMGA2) were highly expressed, while these of miR-217 were poorly expressed in HCC tissues and cells. Upregulation of circBNC2 was related to poor prognosis and tumor node metastasis (TNM) stage. Knockdown of circBNC2 inhibited the HCC progression. Moreover, knockdown of circBNC2 suppressed the levels of Ras, ERK1/2, PCNA, HK2, and OCT4. Notably, circBNC2 functioned as a molecular sponge of microRNA 217 (miR-217) to upregulate the HMGA2 expression. The inhibitory effects of the circBNC2 silence on the growth and stemness of HCC cells, and levels of PCNA, HK2 and OCT4 were aggravated by the miR-217 overexpression, but neutralized by the HMGA2 overexpression. Besides, silencing of circBNC2 blocked the tumor growth through upregulating the expression of miR-217 and downregulating the levels of HMGA2, PCNA2, HK2 and OCT4 in vivo. Thus, the current data confirmed that circBNC2 sponged miR-217 to upregulate the HMGA2 level, thereby contributing to the HCC glycolysis and progression. These findings might present novel insight into the pathogenesis and treatment of HCC.

Thymoquinone Suppresses Angiogenesis in DEN-Induced Hepatocellular Carcinoma by Targeting miR-1-3p

Hepatocellular carcinoma (HCC) is characterized by its high vascularity and metastasis. Thymoquinone (TQ), the main bio-active constituent of Nigella sativa, has shown anticancer and hepatoprotective effects. TQ's anticancer effect is mediated through miRNA regulation. miR-1-3p plays a significant role in various cancers but its role in HCC invasiveness remains poorly understood. Bio-informatics analysis predicted that the 3'-UTR of TIMP3 is a target for miR-1-3p; Rats were equally divided into four groups: Group 1, the negative control; Group 2 received TQ; Group 3 received DEN; and Group 4 received DEN after pretreatment with TQ. The expression of TIMP3, MMP2, MMP9, and VEGF in rats' liver was determined immunohistochemically. RT-qPCR was used to measure the miR-1-3p level in rats' liver, and TIMP3, MMP2, MMP9, and VEGF in the HepG2 cells after being transfected with miR-1-3p mimic or inhibitor; In rats pretreated with TQ, a decreased expression of MMP2, MMP9 and VEGF, and increased expression levels of TIMP3 and miR-1-3p were detected. Treating the HepG2 cells with miR-1-3p mimic led to the upregulation of TIMP3 and downregulation of MMP2, MMP9, and VEGF, and showed a significant delay in wound healing; These results suggested that the anti-angiogenic effect of TQ in HCC may be mediated through the regulation of miR-1-3p.

The role of BCL-2 family proteins in regulating apoptosis and cancer therapy

Apoptosis, as a very important biological process, is a response to developmental cues or cellular stress. Impaired apoptosis plays a central role in the development of cancer and also reduces the efficacy of traditional cytotoxic therapies. Members of the B-cell lymphoma 2 (BCL-2) protein family have pro- or anti-apoptotic activities and have been studied intensively over the past decade for their importance in regulating apoptosis, tumorigenesis, and cellular responses to anticancer therapy. Since the inflammatory response induced by apoptosis-induced cell death is very small, at present, the development of anticancer drugs targeting apoptosis has attracted more and more attention. Consequently, the focus of this review is to summarize the current research on the role of BCL-2 family proteins in regulating apoptosis and the development of drugs targeting BCL-2 anti-apoptotic proteins. Additionally, the mechanism of BCL-2 family proteins in regulating apoptosis was also explored. All the findings indicate the potential of BCL-2 family proteins in the therapy of cancer.

Circular RNA Circ-STIL Contributes to Cell Growth and Metastasis in Hepatocellular Carcinoma via Regulating miR-345-5p/AQP3 Axis

BACKGROUND

Circular RNAs (circRNAs) are implicated in the pathogenesis and development of hepatocellular carcinoma (HCC). However, the function and latent mechanism of circ-STIL in HCC have not been elucidated.

AIMS

This study was designed to explore the precise role and underlying molecular mechanism of circ-STIL in HCC advancement.

METHODS

The expression levels of circ-STIL, SCL/TAL1 interrupting locus (STIL), miR-345-5p and aquaporin-3 (AQP3) were measured by quantitative real-time polymerase chain reaction or western blot. Cell proliferation was assessed by 3-(4,5-dimethylthizol-2-yl)-2,5-diphenyltetrazolium bromide assay and colony formation assay. Cell apoptosis was analyzed by flow cytometry. Transwell assay was conducted to analyze cell migratory and invasive capacities. The interactions among circ-STIL, miR-345-5p and AQP3 were confirmed by dual-luciferase reporter and RNA immunoprecipitation assays. Xenograft tumor model was established to analyze the role of circ-STIL in HCC in vivo.

RESULTS

Circ-STIL was upregulated in HCC tissues and cells. Circ-STIL knockdown inhibited HCC cell progression by reducing cell proliferation, migration and invasion and promoting cell apoptosis. MiR-345-5p was a direct target of circ-STIL, and AQP3 was targeted by miR-345-5p in HCC. Circ-STIL knockdown or miR-345-5p overexpression impeded cell malignant behaviors in HCC cells, and the effects could be reversed by miR-345-5p silence or AQP3 enhancement, respectively. Meanwhile, circ-STIL regulated AQP3 expression by sponging miR-345-5p. Besides, circ-STIL downregulation retarded HCC tumor growth in vivo.

CONCLUSION

Circ-STIL knockdown suppressed HCC development by regulating miR-345-5p/AQP3 pathway, which might provide a promising target for HCC therapy.

Knockdown of lncRNA BDNF-AS inhibited the progression of multiple myeloma by targeting the miR-125a/b-5p-BCL2 axis

Purpose

This study aimed to explore the role of long non-coding RNA (lncRNA) BDNF-AS in the progression of multiple myeloma (MM).

Methods

The expression of BDNF-AS, miR-125a-5p, and miR-125b-5p in MM serum and cell lines were detected by quantitative reverse transcriptase PCR (qRT-PCR). The binding relationships between miR-125a/b-5p and BDNF-AS or Bcl-2 were predicted by Starbase and verified by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) assay and 5-ethynyl-2′-deoxyuridine (EdU) staining assay. Cell migration was evaluated by wound healing assay. The expression levels of apoptosis-related proteins were evaluated by Western blot analysis. The role of BDNF-AS was also investigated in a xenograft tumor model in vivo.

Results

BDNF-AS was significantly upregulated, while miR-125a-5p and miR-125b-5p were downregulated in MM serum and corresponding cancer cell lines. Knockdown of BDNF-AS effectively inhibited the proliferation and migration of MM.1S and U266 cells, and co-transfection of miR-125a-5p or miR-125b-5p inhibitor and sh-BDNF-AS enhanced cell proliferation and migration compared with that in sh-BDNF-AS group. Knockdown of miR-125a-5p or miR-125b-5p significantly enhanced the proliferation and migration of MM.1S and U266 cells, and co-transfection of sh-Bcl-2 and miR-125a/b-5p inhibitor inhibited cell proliferation compared with that in miR-125a/b-5p inhibitor group. Moreover, knockdown of BDNF-AS increased the expression levels of apoptosis-related proteins (cleaved caspase 3 and cleaved PARP), while knockdown of miR-125a-5p or miR-125b-5p reduced the expression levels of these apoptosis-related proteins compared with knockdown of BDNF-AS. Furthermore, knockdown of BDNF-AS effectively suppressed MM tumor growth in vivo.

Conclusion

Our findings revealed that knockdown of BDNF-AS inhibited the progression of MM by targeting the miR-125a/b-5p-Bcl-2 axis, indicating that BDNF-AS might serve as a novel drug target for MM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12979-021-00258-5.

New Cu(II) coordination polymer inhibits cervical cancer development by regulating BRCA1 protein via miR-9-5p

A novel Cu(II)-based coordination polymer [chemical composition, {[CuL(CH₃CO₂)](H₂O)(DMF)}_n (1, DMF = N,N-dimethylformamide) was successfully prepared via Cu(NO₃)₂·3H₂O reaction with HL ligand in DMF and H₂O mixture by using a hetero-donor ligand 4-(bis(4-(4H-1,2,4-triazol-4-yl)phenyl)amino)benzoic acid (HL) featuring carboxylic acid and triazole groups. Reverse transcription-polymerase chain reaction (RT-PCR) was adopted to determine miR-9-5p expression in cervical cancer cells after compound treatment. Bioinformatic analysis and luciferase reporter assay were utilized to confirm miR-9-5p and BRCA1 interaction to discover the potential goal of miR-9-5p in cervical cancer cells. Cell Counting Kit-8 (CCK-8) and reactive oxygen species (ROS) detection kits were adopted to examine cancer cell proliferation and ROS accumulation after compound treatment.

Phospho-Smad3L promotes progression of hepatocellular carcinoma through decreasing miR-140-5p level and stimulating epithelial-mesenchymal transition

BACKGROUND

The transforming growth factor β (TGF-β) activates JNK, phosphorylates Smad3 to linker-phosphorylated Smad3 (pSmad3L), resulting in liver tumorigenesis. However, the effect of pSmad3L on hepatocellular carcinoma (HCC) prognosis is obscure.

AIM

To detect the effect of pSmad3L on HCC prognosis and investigate the mechanism.

METHODS

The expressions of pSmad3L, E-cadherin, vimentin and MicroRNA-140-5p (miR-140-5p) were detected by using immunohistochemistry, immunofluorescence and in situ hybridization. Next, the relationships of pSmad3L and HCC patients' prognoses, pSmad3L and EMT markers, pSmad3L and miR-140-5p were analyzed using Spearman's rank correlation test. JNK/pSmad3L specific inhibitor SP600125 or Smad3 mutant plasmid was used to suppress JNK/pSmad3L pathway, and QPCR assay was performed to investigate the effect of pSmad3L on miR-140-5p level. The proliferation and invasion of hepatoma cells were observed using colony formation assay and transwell assay.

RESULTS

We demonstrated that patient with high level of pSmad3L predicted poor prognosis. Next, we verified that pSmad3L promoted EMT of hepatoma cells in vivo and in vitro. In order to investigate the mechanism, we verified a negative correlation between pSmad3L and miR-140-5p, which was an EMT inhibitor, in the liver tissues of HCC patient and diethylnitrosamine (DEN)-induced rat HCC model. We further used SP600125 or pSmad3L mutant plasmid to decrease pSmad3L level of hepatoma cells, and inhibition of pSmad3L increased miR-140-5p level and suppressed EMT of hepatoma cells.

CONCLUSIONS

JNK/pSmad3L pathway induces EMT by inhibiting miR-140-5p in HCC progression.

Targeting Bcl-2 for cancer therapy

Apoptosis deficiency is one of the most important features observed in neoplastic diseases. The Bcl-2 family is composed of a subset of proteins that act as decisive apoptosis regulators. Research and clinical studies have both demonstrated that the hyperactivation of Bcl-2-related anti-apoptotic effects correlates with cancer occurrence, progression and prognosis, also having a role in facilitating the radio- and chemoresistance of various malignancies. Therefore, targeting Bcl-2 inactivation has provided some compelling therapeutic advantages by enhancing apoptotic sensitivity or reversing drug resistance. Therefore, this pharmacological route turned into one of the most promising routes for cancer treatment. This review discusses some of the well-defined and emerging roles of Bcl-2 as well as its potential clinical value in cancer therapeutics.

Serum MicroRNAs as predictors for fibrosis progression and response to direct-acting antivirals treatment in hepatitis C virus genotype-4 Egyptian patients

BACKGROUND

MicroRNA (miRNAs) are small non-coding molecules that play an important role in hepatitis C virus (HCV) replication and liver diseases progression. The current study aimed to evaluate serum miRNAs as potential biomarkers for diagnosis, monitoring of fibrosis progression and prediction of responses to direct-acting antivirals (sofosbuvir + daclatasvir + ribavirin) in HCV genotype-4 patients.

METHODS

The serum levels of four miRNAs (miRNA-21, 199, 448 and 181c) were assessed in 150 HCV patients and 50 healthy controls using quantitative real-time PCR. The diagnostic accuracy was determined using receiver operating characteristic (ROC) curve.

RESULTS

The four studied miRNAs showed significant upregulation in HCV patients compared with controls. There were significant upregulation of MiR-199 and significant downregulation of miR-448 in late stages of fibrosis with high diagnostic accuracy (area under the curve "AUC" = 0.989%; P < .001) and (AUC = 0.0.672; P > .001), respectively. Regarding response to treatment, only miR-199 showed a significant upregulation in non-responder patients with high diagnostic accuracy (AUC = 0.968; P < .001).

CONCLUSION

miR-199 and miR-448 could serve as valuable non-invasive biomarkers for assessment of liver fibrosis progression. Additionally, miR-199 could be also a potential biomarker for assessment of treatment efficacy among HCV patients. Therefore, miR-199 and miR-448 serum levels should be considered during the treatment of HCV genotype-4 patients in Egypt and the world.

Long non-coding RNA ZEB1-AS1 promotes proliferation and metastasis of hepatocellular carcinoma cells by targeting miR-299-3p/E2F1 axis

There is emerging evidence that dysregulation of long non-coding RNAs (lncRNAs) is associated with hepatocellular carcinoma (HCC). Zinc finger E-box binding homeobox 1 antisense 1 (ZEB1-AS1) functions as an oncogenic regulator in various malignancies. Nonetheless, the potential role of ZEB1-AS1 in HCC remains poorly elucidated. Herein, qRT-PCR was employed for examining ZEB1-AS1, miR-299-3p and E2F1 mRNA expressions in HCC cells and tissues. MTT assay was performed to evaluate cell proliferation. Transwell assay was utilized for evaluating cancer cell migration and invasion. Western blot was employed for measuring E2F1 protein expression. What's more, dual-luciferase reporter assay was utilized for verifying the targeting relationships between ZEB1-AS1 and miR-299-3p, as well as E2F1 and miR-299-3p. It was demonstrated that, in HCC tissues and cells, ZEB1-AS1 expression was markedly increased, and meanwhile, its high expression level is related to the unfavorable clinicopathologic indicators. ZEB1-AS1 overexpression facilitated HCC cell proliferation, migration and invasion, while its knockdown led to the opposite effects. In terms of mechanism, we discovered that ZEB1-AS1 could decoy miR-299-3p and up-regulate E2F1 expression. This work reveals the functions and mechanism of ZEB1-AS1 in HCC tumorigenesis and progression, which provides novel biomarkers and therapeutic targets for HCC.

XIAP, commonly targeted by tumor suppressive miR-3607-5p and miR-3607-3p, promotes proliferation and inhibits apoptosis in hepatocellular carcinoma

MicroRNAs (miRNAs) are frequently aberrantly expressed in hepatocellular carcinoma (HCC) and are involved in its development. However, their role and mechanism in HCC are still not fully elucidated. Differential expression analysis and survival analysis were performed to identify potential miRNAs in HCC and miR-3607 was identified as a candidate therapeutic target and prognostic biomarker. RT-qPCR confirmed the low expression of mature miR-3607-3p and miR-3607-5p in HCC. Functional experiments suggested that both miR-3607-3p and miR-3607-5p significantly inhibited HCC proliferation and induced apoptosis. Next, the detailed mechanism of miR-3607-3p and miR-3607-5p in HCC was explored by combination of bioinformatic analysis and experimental validation, and uncovered that XIAP, a common target gene of miR-3607-3p and miR-3607-5p, was involoved in their tumor suppressive effects. Finally, a XIAP-associated protein-protein interaction network, consisting of 10 positively correlated genes, was established. Collectively, we for the first time suggest that miR-3607-3p and miR-3607-5p inhibit HCC by acting one common target XIAP.

Crosstalk of long non-coding RNAs and EMT: Searching the missing pieces of an incomplete puzzle for lung cancer therapy

BACKGROUND

Lung cancer is considered to be the first place among the cancer-related deaths worldwide and demands novel strategies in the treatment of this life-threatening disorder. The aim of this review is to explore regulation of epithelial-to-mesenchymal transition (EMT) by long non-coding RNAs (lncRNAs) in lung cancer.

INTRODUCTION

LncRNAs can be considered as potential factors for targeting in cancer therapy, since they regulate a bunch of biological processes, e.g. cell proliferation, differentiation and apoptosis. The abnormal expression of lncRNAs occurs in different cancer cells. On the other hand, epithelial-to-mesenchymal transition (EMT) is a critical mechanism participating in migration and metastasis of cancer cells.

METHOD

Different databases including Googlescholar, Pubmed and Sciencedirect were used for collecting articles using keywords such as "LncRNA", "EMT", and "Lung cancer".

RESULT

There are tumor-suppressing lncRNAs that can suppress EMT and metastasis of lung cancer cells. Expression of such lncRNAs undergoes down-regulation in lung cancer progression and restoring their expression is of importance in suppressing lung cancer migration. There are tumor-promoting lncRNAs triggering EMT in lung cancer and enhancing their migration.

CONCLUSION

LncRNAs are potential regulators of EMT in lung cancer, and targeting them, both pharmacologically and genetically, can be of importance in controlling migration of lung cancer cells.

Toosendanin induces apoptosis of MKN‑45 human gastric cancer cells partly through miR‑23a‑3p‑mediated downregulation of BCL2

Toosendanin (TSN) is a tetracyclic triterpenoid extracted from Melia toosendan Sieb, et Zucc, which primarily grows in specific areas of China. Although toosendanin (TSN) exerts antitumoral effects on various human cancer cells, its influence on gastric cancer (GC) is remains to be elucidated. MicroRNAs (miRNAs/miRs) serve crucial roles in apoptosis and proliferation of cancer cells. miR-23a-3p has been shown to be associated with human GC; however, the specific function of miR-23a-3p in GC remains unclear. Therefore, the present study aimed to elucidate the role of miR-23a-3p in the regulation of GC cell proliferation and apoptosis induced in vitro by TSN treatment. Subsequently, apoptosis-related genes expression levels were quantified by reverse transcription-quantitative PCR and western blot analysis, respectively, and the target relationship between miR-23a-3p and BCL2 was determined by luciferase reporter gene analysis. Additionally, cell proliferation and apoptosis experiments were carried out. The results indicated that TSN inhibited proliferation and induced apoptosis in MKN-45 cells. Moreover, it upregulated the expression of miR-23a-3p. B-cell lymphoma-2 (BCL2) was identified as a potential target gene of miR-23a-3p, which was demonstrated to bind to the 3′-untranslated region of BCL2 mRNA, as detected by the luciferase reporter assay. Further studies revealed that BCL2 expression was downregulated following overexpression of miR-23a-3p. In addition, the overexpression of the miR-23a-3p inhibited proliferation, induced G₁ arrest and increased apoptosis in MKN-45 cells. The results of the present study demonstrated that miR-23a-3p inhibited proliferation and induced apoptosis of GC cells, which may be attributable to its direct targeting of BCL2. These results may provide a novel insight into the apoptosis of GC cells, and may lead to investigations into the mechanisms of the effects of TSN.

miR-202 Suppresses Hepatocellular Carcinoma Progression via Downregulating BCL2 Expression

miRNAs play an important role in progression of hepatocellular carcinoma (HCC). In this work, we assessed the function of miR-202 in human HCC and identified BCL2 as its target. We found miR-202 expression was found significantly downregulated, while BCL2 expression was markedly upregulated in HCC tissues and cell lines (HepG2, Hep3B, and HCCLM3). Both miR-202 and BCL2 were closely correlated with major vascular invasion and advanced TNM stage as well as overall survival of HCC patients. Overexpression of miR-202 significantly inhibited cell proliferation, induced apoptosis and cell cycle arrest at the G₀/G₁ phase, and prevented tumor formation in a xenograft nude mouse model. Further, miR-202 dramatically inhibited migration, invasion, and epithelial–mesenchymal transition. miR-202 bound to the 3′-untranslated region (3′-UTR) of BCL2 mRNA and downregulated the expression level of BCL2 protein. Exogenous BCL2 overexpression weakened the inhibitory effects of miR-202, while inhibition of BCL2 enhanced the inhibitory effects of miR-202. In conclusion, miR-202 serves as a tumor suppressor in HCC progression by downregulating BCL2 expression, indicating miR-202 might be a potential target for HCC.

miR-3691-5p promotes hepatocellular carcinoma cell migration and invasion through activating PI3K/Akt signaling by targeting PTEN

Background: The enhanced ability of cancer metastasis is the major cause for the cancer-related death of hepatocellular carcinoma (HCC). Better understanding the mechanisms for the motility of cancer cells will benefit the treatment. Accumulating evidence suggests that aberrant microRNA (miRNA) expression contributes to HCC development and progression, whereas miR-3691-5p has not been reported in HCC.

Purpose: The aim of this study was to elucidate the expression, function and mechanism of miR-3691-5p in HCC.

Methods: Real-time quantitative polymerase chain reaction (qPCR) was performed to detect miR-3691-5p expression in HCC tissues and cell lines database analysis were conducted for detection of the expression of miR-3691-5p in HCC. Then, the association of miR-3691-5p with clinicopathological features of HCC patients were statistically measured. Subsequently, we attempted to observe the effects of miR-3691-5p on migration and invasion of HCC cells by transwell assays. Furthermore, bioinformatics tools and luciferase reporter gene assay as well as recuse experiments were conducted to explore the target of miR-3691-5p in HCC, and to explore whether the target mediated the effects of miR-3691-5p HCC cells.

Results: In the current study, we found that miR-3691-5p expression was elevated in both HCC tissues and cell lines, which was significantly correlated with poor prognosis and clinicopathological features including TNM stage (P=0.016) and vascular invasion (P=0.016). Furthermore, gain-or loss-of function assays demonstrated that miR-3691-5p promoted HCC cell migration and invasion. Luciferase reporter assay confirmed that PTEN was a direct downstream target of miR-3691-5p. Recuse assays showed that restoration of PTEN reversed the effects of miR-3691-5p on HCC cell migration and invasion through decreasing PI3K/Akt signaling.

Conclusion: Our results demonstrated that miR-3691-5p contributes to HCC cell migration and invasion through activating PI3K/Akt signaling by targeting PTEN.

Circular RNA hsa_circ_0001649 inhibits hepatocellular carcinoma progression via multiple miRNAs sponge

Circular RNA (circRNA) exerts an essential role in tumor development. Hsa_circ_0001649 (circ-0001649) was produced at the SHPRH gene locus containing exon 26-29. This study analyzed the specific mechanism of circ-0001649 in influencing the development of hepatocellular carcinoma (HCC). Relative levels of circ-0001649 in HCC cell lines and tissues were examined by qRT-PCR. The direct binding between circ-0001649 and miR-127-5p/miR-612/miR-4688 were verified through Dual-luciferase reporter gene assay, RNA Binding Protein Immunoprecipitation (RIP) assay and western blot detection. In vitro and in vivo regulatory roles of circ-0001649 in proliferative and migratory abilities of HCC were evaluated by EdU, Transwell and tumourigenicity assay, respectively. Results showed that circ-0001649 was markedly decreased in hepatocellular carcinoma cell lines and tumor tissues. Overexpression of circ-0001649 greatly inhibited proliferation and migration of HCC in vitro and in vivo. More importantly, we confirmed that circ-0001649 regulated cellular behaviors of HCC cells by targeting SHPRH. Furthermore, we determined that circ-0001649 served as a ceRNA to sponge miR-127-5p, miR-612 and miR-4688, thus activating SHPRH. In summary, our study showed that circ-0001649 was lowly expressed in HCC and inhibited HCC progression via multiple miRNAs sponge.

Effect of lincRNA-p21 targeting HIF-1α on biological functions of liver cancer cells

The effects of long intergenic non-coding ribonucleic acid (lincRNA)-p21 targeting hypoxia-inducible factor-1α (HIF-1α) on proliferation, apoptosis and migration of liver cancer cells were investigated. MHCC97H liver cancer cells were infected with control lentivirus (control group) and lincRNA-p21 lentivirus (observation group), and control stable cell lines and lincRNA-p21 stable cell lines were screened and obtained by using puromycin. The expression levels of lincRNA-p21 messenger RNA (mRNA) in the control and observation groups were analyzed via reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Bioinformatics was used to search for the lincRNA-p21 target. The expression of target gene was analyzed via western blotting, and the proliferation, apoptosis, migration and in vivo tumor formation of MHCC97H cells in the control and observation groups were also analyzed. Compared with that in control group, the lincRNA-p21 mRNA level in observation group was increased significantly (P<0.05). It was found via bioinformatic comparison that HIF-1α was one of the targets of lincRNA-p21. Results of Western blotting revealed that the expression level of HIF-1α protein in cells in observation group was significantly downregulated (P<0.05). Besides, the level of vascular endothelial growth factor (VEGF) protein in cells in control group was obviously higher than that in observation group (P<0.05). Compared with those in control group, the cell proliferation and migration capacities in observation group were markedly reduced, but the apoptosis level was significantly increased (P<0.05). According to the in vivo tumor formation assay, the cell proliferation rate in control group was obviously higher than that in observation group (P<0.05). The number of tumor blood vessels in cells in control group was obviously reduced compared with that in observation group (P<0.05). lincRNA-p21 can significantly downregulate the level of HIF-1α, thus downregulating the expression of VEGF and affecting the cell proliferation, apoptosis and migration.

miR-1-3p suppresses proliferation of hepatocellular carcinoma through targeting SOX9

Background

Liver cancer was the fourth leading cause of cancer-related death in 2015. Hepatocellular carcinoma (HCC) is the most common type of liver cancer. miR-1-3p plays important roles in cancer, including prostate, bladder, lung cancer, and colorectal carcinoma. The function of miR-1-3p in HCC remains poorly understood.

Methods

qRT-PCR was performed to detect the miR-1-3p expression in HCC cell lines (HCCLM3, Hep3B, Bel-7404, SMMC-7721) and the normal human hepatic cell line (LO2). HCCLM3 and Bel-7404 cells were transfected with miR-1-3p mimic or scramble control followed by water-soluble tetrazolium salt (WST-1) assay. Western bolt analysis was performed to determine the protein levels. TargetScan7.1 (http://www.targetscan.org/vert_71/) was used to predict the potential targets of miR-1-3p. SRY (sex determining region Y)-box 9 (SOX9), which has been previously shown to play an important role in HCC, was found to be a target of miR-1-3p. Luciferase reporter assay was used to explore the targeting of miR-1-3p on SOX9. For in vivo tumorigenesis assay, HCCLM3 cells with stable overexpression of miR-1-3p or control plasmid were injected subcutaneously into the flank of the SCID mice and animals were monitored for tumor growth.

Results

miR-1-3p was significantly downregulated in HCC cell lines (HCCLM3, Hep3B, Bel-7404, and SMMC-7721) compared to normal human hepatic cell line (LO2). Overexpression of miR-1-3p significantly inhibited the proliferation and induced apoptosis in HCCLM3 and Bel-7474 cells. SOX9 was a direct target of miR-1-3p in HCC cells. Inhibition of SOX9 significantly inhibited the proliferation of HCCLM3 and Bel-7474 cells. In vivo, overexpression of miR-1-3p decreased tumor volume in a xenograft model.

Conclusion

These results highlight the role of miR-1-3p in HCC. Overexpression of miR-1-3P inhibited the proliferation of HCC at least partly due to the regulation of SOX9. miR-1-3p may be a promising therapeutic candidate for HCC.