The Diverse Mechanisms of miRNAs and lncRNAs in the Maintenance of Liver Cancer Stem Cells

Deciphering Role of lncRNA 91H in Liver Cancer: Impact on Tumorigenesis

OBJECTIVE

This study aimed to investigate functional role of long ncRNA (lncRNA) 91H in liver cancer tumorigenesis, focusing on its effect on cell proliferation, apoptosis, cell cycle progression, migration, invasion, epithelial-mesenchymal transition (EMT) and In vivo tumor growth.

MATERIALS AND METHODS

In this experimental study, liver cancer tissues and cell lines were analyzed for lncRNA 91H expression using quantitative reverse transcription polymerase chain reaction (qRT-PCR). By employing si-RNA to silence 91H, we aimed to gain a more in-depth understanding of its specific contributions and effects within these cells. Cell proliferation was assessed through the CCK-8 assay, while apoptosis and cell cycle progression were quantified using Annexin V-FITC staining and flow cytometry, respectively. Migration and invasion capabilities of liver cancer cells were assessed through transwell assay. EMT was assessed by analyzing protein expression levels of EMT-associated markers through western blotting. In vivo effect of 91H was assessed through xenograft experiments.

RESULTS

Significantly higher levels of lncRNA 91H were observed in the liver cancer tissues and cell lines, than the normal cells. Silencing 91H in liver cancer cells led to a notable reduction of cell proliferation by inducing apoptosis and arresting the cell cycle. Liver cancer cells with decreased 91H expression exhibited diminished migration and invasion abilities, suggesting a role for 91H in promoting these processes. Furthermore, 91H knockdown weakened EMT in liver cancer cells, indicating its involvement in modulating this critical cellular transition. Furthermore, growth of subcutaneous xenograft tumors and weight was effectively suppressed by sh-lncRNA 91H.

CONCLUSION

Our study strongly supports lncRNA 91H's role in liver cancer progression by enhancing proliferation, migration, invasion, and EMT. Targeting 91H reduced in vivo tumor growth, highlighting its potential as a therapeutic liver cancer target. These findings suggest 91H's pivotal role in liver cancer aggressiveness, opening doors for future therapeutic approaches.

LncRNA NKILA Promotes Epithelial-Mesenchymal Transition of Liver Cancer Cells by Targeting miR-485-5p

Objective

Liver cancer (LC), one of the familiar malignancies, has a very high morbidity all over the world. The onset of the disease is hidden, and the patients usually do not express any special symptoms. Most of them will have been developed to the middle and later stage when they are diagnosed. This is one of the main reasons why the prognosis of LC is extremely pessimistic all the year round. Recently, researchers have focused mainly on molecular studies, among which LncRNA is a hot spot. This research aims to explore the biological behaviors of LncRNA NKILA and miR-485-5p in LC cells and verify the relationship between them, thereby providing a new theoretical basis for future prevention and treatment.

Methods

Ninety-four early LC patients admitted to our hospital from January 2015 to January 2017 were regarded as the research objects. In addition, human LC cells SMMC-7721, HepG2, and normal liver cells HL-7702 were purchased. The LncRNA NKILA and miR-485-5p level in cancer and adjacent tissues, LC, and normal liver cells of patients was tested by PCR. Patients were followed up for 3 years. Then, LncRNA NKILA and miR-485-5p's effects on prognosis and cell biological behavior were analyzed. At last, the relationship between LncRNA NKILA and miR-485-5p was assessed by a dual-luciferase reporter assay.

Results

The LncRNA NKILA expression was high in LC tissues and cells (P < 0.050), while miR-485-5p was low compared with the normal adjacent tissues (P < 0.050). Prognostic follow-up manifested that high LncRNA NKILA or low miR-485-5p could predict the poor prognosis and high mortality risk of the patients (P < 0.050). LC cells with downregulated LncRNA NKILA documented inhibited proliferation, invasion, and EMT, while the apoptosis level of the cells increased (P < 0.050). The proliferation, invasion, and EMT were inhibited by miR-485-5p increase, while the apoptosis of the cells decreased after upregulating miR-485-5p (P < 0.050). Online websites predicted that LncRNA NKILA had a binding site with miR-485-5p, and dual-luciferase reporter assay confirmed that LncRNA NKILA could directly target with miR-485-5p (P < 0.050). The miR-485-5p in LC cells increased after LncRNA NKILA was silenced (P < 0.050). The rescue experiment documented that LncRNA NKILA inhibition on LC cells was reversed by inhibiting miR-485-5p (P < 0.050).

Conclusion

The LncRNA NKILA with high expression advances LC cell proliferation, invasion, and EMT by targeting miR-485-5p.

Hypericin Exerts Detrimental Effect on Huh-7 As a Delegacy of Hepatocellular Carcinoma: A P53 Dependent Pathway

Background:

Hepatocellular carcinoma is the most common type of liver cancer which arises from the main cells in the liver. We address many studies investigating anti-cancer role of hypericin, however the proposing corresponding molecular pathway seems to be still a debate. Therefore, the present study aimed to evaluate the apoptotic effect of hypericin on the Huh7 as the liver cancer cell line and its relation with the gate keeper gene P53.

Materials and Methods:

In this study, the Huh7 cell line and fibroblast cells (as control group) were treated with different concentrations of hypericin for 24 and 48 hours. Detection of cell death was performed by MTT assay and flow cytometry. The expression of bax, bcl2 and p53 mRNAs was evaluated by Real-time PCR. Also, Immunocytochemistry (ICC) analysis was used for further evaluation of P53expression.

Results:

The results showed that hypericin has a dose-dependent cytotoxic effect on the Huh7 cell line, with no or marginal effect on fibroblastic cells. According to flow cytometry results, about 53%cells underwent apoptosis after exposure to LD50 of hypericin for 24 hours. Real-time PCR data demonstrated that the pro-apoptotic genes Bax and P53 expression level increased. Expectedly ICC results confirmed the up-regulation of P53 proteins in treated samples.

Conclusion:

Our results indicate the cytotoxicity of hypericin on Huh7 cells by affecting the expression of the gate keeper gene P53; furthermore it is suggested that this herb can be utilized simultaneously with modalities targeting P53 up-regulation or related molecular pathways.

Cancer stem cell characteristics and their potential as therapeutic targets

Cancer stem cells (CSCs) are a tumour subpopulation whose capacity for self-renewal, differentiation and proliferation generates unfavourable patient outcomes, including therapeutic resistance and metastasis. Much research has focused on the generation, biomarkers and therapeutic resistance of CSCs, as well as the development of CSC-targeted therapies. Reviews to date have either addressed general CSC characteristics or focused on CSCs from a well-studied cancer. Increasingly, specific treatment plans based on identification of molecular features and biomarkers of a patient's cancer, rather than classification according to tissue origin or bulk tumour properties, are leading to better patient outcomes. Here, we compare CSC characteristics, specifically their biomarkers and molecular features, and identify those that are common to a number of cancers. Identification of CSC markers that suggest therapeutic strategies has led to several successful in vitro and animal tests, recommending clinical trials of treatments with potentially enhanced therapeutic benefits, especially for recurring cancers.

Current understanding of epigenetics mechanism as a novel target in reducing cancer stem cells resistance

At present, after extensive studies in the field of cancer, cancer stem cells (CSCs) have been proposed as a major factor in tumor initiation, progression, metastasis, and recurrence. CSCs are a subpopulation of bulk tumors, with stem cell-like properties and tumorigenic capabilities, having the abilities of self-renewal and differentiation, thereby being able to generate heterogeneous lineages of cancer cells and lead to resistance toward anti-tumor treatments. Highly resistant to conventional chemo- and radiotherapy, CSCs have heterogeneity and can migrate to different organs and metastasize. Recent studies have demonstrated that the population of CSCs and the progression of cancer are increased by the deregulation of different epigenetic pathways having effects on gene expression patterns and key pathways connected with cell proliferation and survival. Further, epigenetic modifications (DNA methylation, histone modifications, and RNA methylations) have been revealed to be key drivers in the formation and maintenance of CSCs. Hence, identifying CSCs and targeting epigenetic pathways therein can offer new insights into the treatment of cancer. In the present review, recent studies are addressed in terms of the characteristics of CSCs, the resistance thereof, and the factors influencing the development thereof, with an emphasis on different types of epigenetic changes in genes and main signaling pathways involved therein. Finally, targeted therapy for CSCs by epigenetic drugs is referred to, which is a new approach in overcoming resistance and recurrence of cancer.

Pluripotency inducing Yamanaka factors: role in stemness and chemoresistance of liver cancer

Introduction: Liver cancer is a major cause of mortality and is characterized by the transformation of cells into an uncontrolled mass of tumor cells with many genetic and epigenetic changes, which lead to the development of tumors. A small subpopulation of cell population known as Cancer Stem Cells (CSCs) is responsible for cancer stemness and chemoresistance. Yamanaka factors [octamer-binding transcription factor 4 (OCT4), SRY (sex-determining region Y)-box 2 (SOX2), kruppel-like factor 4 (KLF4), and Myelocytomatosis (MYC); OSKM] are responsible for cancer cell stemness, chemoresistance, and recurrence.Area covered: We cover recent discoveries and investigate the role of OSKM in inducing pluripotency and stem cell-like properties in various cancers with special emphasis on liver cancer. We review Yamanaka factors' role in stemness and chemoresistance of liver cancer.Expert opinion: In CSCs, including liver CSCs, the deregulation of various signaling pathways is one of the major reasons for stemness and drug resistance and is primarily due to OSKM. OSKM are responsible for tumor heterogeneity which renders targeting drug useless after a certain period. These factors can be exploited to understand the underlying mechanism of cancer stemness and resistance to chemotherapeutic drugs.

miR-34a-5p suppresses the invasion and metastasis of liver cancer by targeting the transcription factor YY1 to mediate MYCT1 upregulation

BACKGROUND

In recent years, microRNAs (miRNAs) are reported to act as molecular biomarkers for cancer diagnosis, treatment, and prognosis (including liver cancer) and to be involved in the development and progression of cancer and other physiological and pathological changes. However, the role of miR-34a-5p in liver cancer is still largely unknown.

METHODS

In our study, the expression of miR-34a-5p in liver cancer tissues and HCC cell lines was detected by qRT-PCR. The CCK-8, scratch wound-healing motility and Transwell assays were used to evaluate the effect on cell proliferation, migration and invasion. The expression of YY1, E-cadherin, N-cadherin and vimentin was analysed by western blotting. The dual luciferase assay was performed to confirm whether YY1 is a target of miR-34a-5p. The combination of YY1 and MYCT1 was detected by chromatin immunoprecipitation (ChIP) assay.

RESULTS

The results showed that miR-34a-5p was downregulated in liver cancer tissues and HCC cell lines. Overexpression of miR-34a-5p inhibited the proliferation, migration and invasion of liver cancer cells. YY1 was a direct target of miR-34a-5p, and the expression of YY1 could reverse the influence of miR-34a-5p on the proliferation, migration and invasion of liver cancer cells. YY1 inhibited MYCT1 expression by directly binding to its promoter region, and knockdown of MYCT1 reversed the influence of miR-34a-5p on the proliferation, migration and invasion of liver cancer cells.

CONCLUSION

Our results suggest that miR-34a-5p could inhibit the invasion and metastasis of hepatoma cells by targeting YY1-mediated MYCT1 transcriptional repression.

lncRNA FOXD2-AS1 promotes hemangioma progression through the miR-324-3p/PDRG1 pathway

Background

Long non-coding RNAs (lncRNAs) FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) are reported could function as tumor promoter in several cancers. However, its role in hemangioma was not reported to yet.

Methods

Expression level of FOXD2-AS1 in hemangioma tissues and cells was explored using quantitative reverse-time PCR. Cell counting kit-8 (CCK-8) assay, colony formation assay, wound-healing assay, and transwell invasion assay were conducted to measure the roles of FOXD2-AS1. In addition, the levels of markers for proliferation and Epithelial-Mesenchymal Transition were investigated. Connection of FOXD2-AS1 and mcroRNA-324-3p (miR-324-3p) or miR-324-3p and p53 and DNA damage regulated 1 (PDRG1) was analyzed with bioinformatic analysis method and dual-luciferase activity reporter assay.

Results

Here, we found that FOXD2-AS1 was highly expressed in proliferating-phase hemangioma tissues compared with the involuting-phase hemangioma tissues. Functionally, FOXD2-AS1 knockdown suppressed cell proliferation, colony formation, migration, and invasion in vitro. Conversely, overexpression of FOXD2-AS1 promoted tumor growth in vitro. Mechanistically, FOXD2-AS1 inversely regulated miR-324-3p abundance in hemangioma cells. We also found FOXD2-AS1 acted as a competing endogenous RNA (ceRNA) by directly sponging miR-324-3p to regulate PDRG1 expression. In addition, the knockdown of PDRG1 reversed the stimulation effects of FOXD2-AS1 overexpression on HA cells.

Conclusion

To conclude, our study sheds novel light on the biological roles of FOXD2-AS1 in hemangioma, which may help the development of targeted therapy method for cancer.

Long non-coding RNA GAS5 is critical for maintaining stemness and induces chemoresistance in cancer stem-like cells derived from HCT116

Long non-coding RNAs (lncRNAs) are recognized as critical regulators of self-renewal in human cancer stem-like cells (CSCs), which are a subpopulation of cancer cells primarily responsible for the malignant features of cancer. However, most CSC-related lncRNAs remain unidentified. The results of the present study suggested that growth-arrest-specific transcript 5 (GAS5), a tumor suppressor, exhibited increased expression and was associated with malignant features in human colorectal cancer cell HCT116-derived CSCs. Phenotypic analysis indicated that GAS5 knockdown by specific siRNA significantly decreased CSC self-renewal capacity, proliferation and migration. Moreover, GAS5 knockdown sensitized CSCs to the chemotherapeutic agents 5-fluorouracil and doxorubicin by inducing apoptosis detected by Annexin V-FITC/PI double staining. Inhibition of Nodal growth differentiation factor (NODAL) signaling, which has been reported to be protected by GAS5, presented similar chemosensitivity effects to the GAS5 knockdown results. The present study also assessed the effects of GAS5 overexpression on HCT116 cells, and revealed that overexpression of GAS5 sensitized HCT116 cells to chemotherapeutic agents, which is the opposite of the effect observed in CSCs derived from HCT116 cells. Therefore, it was hypothesized that GAS5 may function as a critical factor for maintaining stemness and that it may exert protective effects on CSCs in a NODAL-dependent manner. Collectively, the results of the present study indicate that GAS5 may be a promising therapeutic target for overcoming malignant features and chemoresistance in colorectal cancer cells.

microRNA-454 promotes liver tumor-initiating cell expansion by regulating SOCS6

Tumor-initiating cells (T-ICs) are involved in the tumorigenesis, progression, drug resistance and recurrence of hepatocellular carcinoma (HCC). However, the underlying mechanism for the propagation of liver T-ICs remains unclear. Herein, we find that miR-454 is upregulated in liver T-ICs and has an important function in liver T-ICs. Functional studies have revealed that knockdown of miR-454 inhibits liver T-IC self-renewal and tumorigenesis. Conversely, forced miR-454 expression promotes liver T-IC self-renewal and tumorigenesis. Mechanistically, we found that miR-454 downregulates SOCS6 expression in liver T-ICs. The correlation between miR-454 and SOCS6 is validated in human HCC tissues. Furthermore, HCC cells that overexpress miR-454 are resistant to sorafenib treatment. Analysis of patient-derived xenografts (PDXs) further demonstrates that miR-454 may predict sorafenib benefits in HCC patients. In conclusion, our findings reveal the crucial role of miR-454 in liver T-IC expansion and sorafenib response.

Deciphering the Mounting Complexity of the p53 Regulatory Network in Correlation to Long Non-Coding RNAs (lncRNAs) in Ovarian Cancer

Amongst the various gynecological malignancies affecting female health globally, ovarian cancer is one of the predominant and lethal among all. The identification and functional characterization of long non-coding RNAs (lncRNAs) are made possible with the advent of RNA-seq and the advancement of computational logarithm in understanding human disease biology. LncRNAs can interact with deoxyribonucleic acid (DNA), ribonucleic acid (RNA), proteins and their combinations. Moreover, lncRNAs regulate orchestra of diverse functions including chromatin organization and transcriptional and post-transcriptional regulation. LncRNAs have conferred their critical role in key biological processes in human cancer including tumor initiation, proliferation, cell cycle, apoptosis, necroptosis, autophagy, and metastasis. The interwoven function of tumor-suppressor protein p53-linked lncRNAs in the ovarian cancer paradigm is of paramount importance. Several lncRNAs operate as p53 regulators or effectors and modulates a diverse array of functions either by participating in various signaling cascades or via interaction with different proteins. This review highlights the recent progress made in the identification of p53 associated lncRNAs while elucidating their molecular mechanisms behind the altered expression in ovarian cancer tumorigenesis. Moreover, the development of novel clinical and therapeutic strategies for targeting lncRNAs in human cancers harbors great promise.

Post-transcriptional regulations of cancer stem cell homeostasis

PURPOSE OF REVIEW

Although extensively studied for over a decade, gene expression programs established at the epigenetic and/or transcriptional levels do not fully characterize cancer stem cells (CSC). This review will highlight the latest advances regarding the functional relevance of different key post-transcriptional regulations and how they are coordinated to control CSC homeostasis.

RECENT FINDINGS

In the past 2 years, several groups have identified master post-transcriptional regulators of CSC genetic programs, including RNA modifications, RNA-binding proteins, microRNAs and long noncoding RNAs. Of particular interest, these studies reveal that different post-transcriptional mechanisms are coordinated to control key signalling pathways and transcription factors to either support or suppress CSC homeostasis.

SUMMARY

Deciphering molecular mechanisms coordinating plasticity, survival and tumourigenic capacities of CSCs in adult and paediatric cancers is essential to design new antitumour therapies. An entire field of research focusing on post-transcriptional gene expression regulation is currently emerging and will significantly improve our understanding of the complexity of the molecular circuitries driving CSC behaviours and of druggable CSC weaknesses.

miR-664b-5p Inhibits Hepatocellular Cancer Cell Proliferation Through Targeting Oncogene AKT2

Background: miR-664b-5p accelerates the development of certain cancers, but the role of miR-664b-5p in hepatocellular carcinoma (HCC) has been less reported. Therefore, the authors aimed to study the role of miR-664b-5p in HCC progression. Materials and Methods: miR-664b-5p expression in liver cancer and adjacent tissues, and in HepG2 and SUN-475 cells, was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Relationship between miR-664b-5p and AKT2 was predicted by TargetScan and confirmed by dual-luciferase reporter assay, and gene or protein expressions were determined by performing qRT-PCR and Western blotting. The viability and apoptosis, and the migration and invasion of HepG2 and SUN-475 cells were determined by CCK-8 assay and flow cytometry, and transwell assay, respectively. Results: Downregulated miR-664b-5p was observed in hepatocellular cancer tissues. Functional analyses revealed that miR-664b-5p mimic suppressed viability, migration, and invasion, but promoted apoptosis in HepG2 and SUN-475 cells. AKT2 was a target of miR-664b-5p, whose mimics inhibited the expression of AKT2. However, upregulated AKT2 promoted viability, migration, and invasion, but inhibited apoptosis in HepG2 and SUN-475 cells, and such effects were reversed by miR-664b-5p mimics. Conclusions: miR-664b-5p acts as a cancer suppressor through negatively regulating AKT2 expression in HepG2 and SUN-475 cells, suggesting that miR-664b-5p could be a protective target for HCC patients.

microRNA-29a regulates liver tumor-initiating cells expansion via Bcl-2 pathway

MicroRNAs (miRNAs) participate in tumorigenesis, progression, recurrence and drug resistance of hepatocellular carcinoma (HCC). However, few miRNAs have been identified and entered clinical practice. Herein, we report that miR-29a is downregulated in tumor-initiating cells (T-ICs) and has an important function in liver T-ICs. Functional studies revealed that miR-29a knockdown promotes liver T-ICs self-renewal and tumorigenesis. Conversely, a forced miR-29a expression inhibits liver T-ICs self-renewal and tumorigenesis. Mechanistically, we find that miR-29a downregulates Bcl-2 via binding its mRNA 3'UTR in liver T-ICs. The correlation between miR-29a and Bcl-2 is validated in human HCC tissues. Furthermore, the miR-29a expression determines the responses of hepatoma cells to sorafenib treatment. Analysis of patient-derived xenografts (PDXs) further demonstrated that the miR-29a high patients are more sensitive to sorafenib treatment. In conclusion, our findings revealed the crucial role of the miR-29a in liver T-ICs expansion and sorafenib response, rendering miR-29a as an optimal target for the prevention and intervention of HCC.

miR-219 regulates liver cancer stem cell expansion via E-cadherin pathway

Liver cancer stem cells contribute to tumorigenesis, progression, recurrence and drug resistance of hepatocellular carcinoma (HCC). However, the underlying mechanism for the propagation of liverCSCs is not fully understood yet. Here we show that miR-219 is upregulated in liver CSCs. Knockdown of miR-219 attenuates the self-renewal and tumorigenicity of liver CSCs. Conversely, miR-219 overexpressing enhances the self-renewal and tumorigenicity of liver CSCs.Mechanistically,miR-219 downregulates E-cadherin via itsmRNA 3'UTR in liver CSCs. The correlation between miR-219 and E-cadherin is validated in human HCC tissues. Furthermore, the miR-219 expression determines the responses of hepatoma cells to sorafenib treatment. Our findings indicate that miR-219 plays a critical role in liver CSCs expansion and sorafenib response, rendering miR-219 as an optimal target for the prevention and intervention of HCC.Abbreviations: HCC: Hepatocellular carcinoma; CSCs: cancer stem cells; DMEM: Dulbecco's modified Eagle's medium; FBS: fetal bovine serum; OS: overall survival.

Two GEO MicroRNA Expression Profile Based High-Throughput Screen to Identify MicroRNA-31-3p Regulating Growth of Medullary Thyroid Carcinoma Cell by Targeting RASA2

Background

Medullary thyroid carcinoma (MTC), a rare type of thyroid cancer, is a big challenge in clinical treatment. However, the pathogenesis of MTC remains poorly understand. MicroRNAs (miRNAs) were previously demonstrated to be involved in the pathogenesis of MTC, however, the roles of majority of miRNAs in MTC are still undetermined.

Material/Methods

Two GEO miRNA expression profiles (GSE40807, GSE97070) were downloaded, and the differentially expressed miRNAs (DEmiRNAs) of GSE40807 and GSE97070 were analyzed by bioinformatics methods. Expressions of miRNAs were detected by quantitative real-time polymerase chain reaction; cell proliferation was examined through Cell Counting Kit-8, colony formation and in vivo tumor growth assays; the interaction between miRNA and mRNA was verified by dual-luciferase reporter assay; functional analysis of target genes was performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID, www.david.ncifcrf.gov) software.

Results

Ten miRNAs were identified to be dysregulated in both GSE40807 and GSE97070 datasets, and miR-31-3p showed the highest change fold (Log fold change=−3.460625 in GSE40807 and Log fold change=−0.07084374 in GSE97070). MiR-31-3p expression was significantly downregulated in MTC, and low miR-31-3p expression showed a poor prognosis relative to high miR-31-3p expression (P<0.05). Functionally, miR-31-3p inhibited MTC cell proliferation in vitro and in vivo. Functional analysis also showed that the target genes of miR-31-3p were involved in numerous of biochemical processes and pathways, of which Ras signaling pathway was selected for further study. RASA2, overexpressed in MTC, were negatively regulated by miR-31-3p. In addition, we found that knockdown of RASA2 inhibited MTC cell proliferation.

Conclusions

Reduced expression level of miR-31-3p might play a key role in the tumorigenesis of MTC by targeting critical pathways, especially Ras signaling pathway.

lncRNA CASC9 regulates cell migration and invasion in hemangioma endothelial cells by targeting miR-125a-3p/Nrg1

Background

Despite being one of the most common benign tumors, the prevalence and pathogenesis of hemangiomas (HAs) are poorly understood. We aimed to identify the biological role of the long non-coding RNA (lncRNA) CASC9 in the HA-derived endothelial cell (HDECs) phenotype as well as elucidate the mechanism involved.

Methods

The expression of CASC9 was identified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). the effect of CASC9 on cell proliferation, migration and invasion of HDECs were examined by CCK8, wound healing, and transwell assay, respectively. Bioinformatics analysis and a luciferase reporter assay were utilized to investigated the mechanisms involved. The in vivo tumorigenesis capability of CASC9 on HA was also evaluated.

Results

The expression of CASC9 was significantly elevated in HA tissue compared to normal tissue. Down-regulation of CASC9 inhibited proliferation, migration, and invasion of HDECs. The translation of cyclinD1, N-cadherin, Twist, and MMP2 was also decreased by CASC9 knockdown treatment. Furthermore, CASC9 over-expression exerted the opposite effect of proliferation, migration, and invasion of HDECs. We also found that CASC9 interacts with miR-125a-3p/Nrg1 to regulate cellular functions. Interestingly, miR-125a-3p can reverse the effect of CASC9 on proliferation, migration, and invasion of HDECs. Together, the clinical data showed that CASC9 expression is negatively correlated with miR-125a-3p expression and positively correlated with Nrg1 expression. CASC9 also exerted anti-tumorigenesis capability in vivo.

Conclusion

Our study indicates that CASC9 accelerates cell growth and invasion of HDECs and provides new insights for the diagnosis and molecular therapy of HA.