Upregulated lncRNA CASC2 May Inhibit Malignant Melanoma Development Through Regulating miR-18a-5p/RUNX1

Deregulated Long Non-Coding RNAs (lncRNA) as Promising Biomarkers in Hidradenitis Suppurativa

Background/Objectives: In recent times, epigenetics alterations in Hidradenitis suppurativa (HS) have been explored and exploited translationally to guide investigation of new therapeutic approaches. On the other hand, long noncoding RNAs (LncRNAs), main regulators of the epigenetic status of the human genome, have been scarcely investigated, notwithstanding their potential relevance in broad pathogenesis comprehension. Here, we aim to explore the methylation pattern of lncRNAs in HS. Methods: In this case-control study, 24 HS patients and age-, sex- and BMI-matched controls were analyzed to characterize the methylome of lncRNA genes in peripheral blood cells. Gene ontology analysis (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, protein-protein interaction (PPI) network, and MCODE analysis were performed. Results: A set of fifteen lncRNA genes exhibited significantly differential methylation patterns, with ten of them showing hypomethylation and five displaying hypermethylation at specific CpG sites. The hypomethylated lncRNA genes were DLEU2, MESTIT1, CASC2, TUG1, KCNQ1DN, PSORS1C3, PCA3, DSCR8, RFPL1S, and PVT1, while the hypermethylated ones were HAR1A, FAM66B, SNHG9, HCG9, and HCP5. These lncRNA genes have been linked to various important biological processes, including cell proliferation, apoptosis, inflammation, chronic inflammatory skin diseases, and wound healing. Their altered methylation status suggests potential roles in regulating these processes, and may contribute to HS pathogenesis and healing mechanisms. Conclusions: This study revealed an interesting dysregulation pattern of definite lncRNAs in the methylome which is linked to both the development of HS and its comorbidities. Epigenetically altered lncRNAs genes could represent useful biomarkers, and could help in guiding innovative treatment strategies.

YY1-induced lncRNA00511 promotes melanoma progression via the miR-150-5p/ADAM19 axis

Increasing evidence indicates that long noncoding RNAs (lncRNAs) are therapeutic targets and key regulators of tumors development and progression, including melanoma. Long intergenic non-protein-coding RNA 511 (LINC00511) has been demonstrated as an oncogenic molecule in breast, stomach, colorectal, and lung cancers. However, the precise role and functional mechanisms of LINC00511 in melanoma remain unknown. This study confirmed that LINC00511 was highly expressed in melanoma cells (A375 and SK-Mel-28 cells) and tissues, knockdown of LINC00511 could inhibit melanoma cell migration and invasion, as well as the growth of subcutaneous tumor xenografts in vivo. By using Chromatin immunoprecipitation (ChIP) assay, it was demonstrated that the transcription factor Yin Yang 1 (YY1) is capable of binding to the LINC00511 promoter and enhancing its expression in cis. Further mechanistic investigation showed that LINC00511 was mainly enriched in the cytoplasm of melanoma cells and interacted directly with microRNA-150-5p (miR-150-5p). Consistently, the knockdown of miR-150-5p could recover the effects of LINC00511 knockdown on melanoma cells. Furthermore, ADAM metallopeptidase domain expression 19 (ADAM19) was identified as a downstream target of miR-150-5p, and overexpression of ADAM19 could promote melanoma cell proliferation. Rescue assays indicated that LINC00511 acted as a competing endogenous RNA (ceRNA) to sponge miR-150-5p and increase the expression of ADAM19, thereby activating the PI3K/AKT pathway. In summary, we identified LINC00511 as an oncogenic lncRNA in melanoma and defined the LINC00511/miR-150-5p/ADAM19 axis, which might be considered a potential therapeutic target and novel molecular mechanism the treatment of patients with melanoma.

LncRNA HAGLR May Aggravate Melanoma Malignancy Via miR-4644/ASB11 Pathway

In this study, we aimed to assess the biological functions of HAGLR and its underlying mechanisms in melanoma. HAGLR and ASB11 were knocked down by transfection with the corresponding siRNAs. Meanwhile, miR-4644 was downregulated using the miR-4644 inhibitor treatment. The target interactions among the three molecules were demonstrated using dual-luciferase reporter and RNA immunoprecipitation assays. The levels of HAGLR, miR-4644, and ASB11 in melanoma cells and tissues were assessed using quantitative real‑time PCR and western blotting. The functions and mechanisms underlying HAGLR action in melanoma progression were examined using Cell Counting Kit-8, Transwell, Caspase-3 activity, and xenograft tumor formation assays. HAGLR and ASB11 expression were elevated, whereas that of miR-4644 was downregulated in melanoma cells and tissues. The viability and migration of melanoma cells (A875 and A375) were markedly suppressed by the knockdown of HAGLR and ASB11 but promoted following miR-4644 inhibitor transfection. In contrast, apoptosis showed the opposite trend. In vivo, tumor weight declined considerably with downregulation of HAGLR. Mechanistically, HAGLR sponges miR-4644, increasing the levels of ASB11 and further aggravating melanoma. It latter negatively targets ASB11 in melanoma cells. Hence, the HAGLR-miR-4644-ASB11 axis may be a promising target for melanoma treatment.

RUNX1-Regulated Signaling Pathways in Ovarian Cancer

Ovarian cancer is the leading cause of gynecological death worldwide, and its poor prognosis and high mortality seriously affect the life of ovarian cancer patients. Runt-related transcription factor 1 (RUNX1) has been widely studied in hematological diseases and plays an important role in the occurrence and development of hematological diseases. In recent years, studies have reported the roles of RUNX1 in solid tumors, including the significantly increased expression of RUNX1 in ovarian cancer. In ovarian cancer, the dysregulation of the RUNX1 signaling pathway has been implicated in tumor progression, metastasis, and response to therapy. At the same time, the decreased expression of RUNX1 in ovarian cancer can significantly improve the sensitivity of clinical chemotherapy and provide theoretical support for the subsequent diagnosis and treatment target of ovarian cancer, providing prognosis and treatment options to patients with ovarian cancer. However, the role of RUNX1 in ovarian cancer remains unclear. Therefore, this article reviews the relationship between RUNX1 and the occurrence and development of ovarian cancer, as well as the closely regulated signaling pathways, to provide some inspiration and theoretical support for future research on RUNX1 in ovarian cancer and other diseases.

Discovery and Potential Functional Characterization of Long Noncoding RNAs Associated with Familial Acne Inversa with NCSTN Mutation

BACKGROUND

Long noncoding RNAs (lncRNAs) are associated with many dermatologic diseases. However, little is known about the regulatory function of lncRNAs in familial acne inversa (AI) patients with nicastrin (NCSTN) mutation.

OBJECTIVES

The aim of this study was to explore the regulatory function of lncRNAs in familial AI patients with NCSTN mutation.

METHODS

The expression profiles of lncRNAs and mRNAs in skin tissues from familial AI patients with NCSTN mutation and healthy individuals were analysed in this study via RNA sequencing (RNA-seq).

RESULTS

In total, 359 lncRNAs and 1,863 mRNAs were differentially expressed between the two groups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed that the dysregulated mRNAs targeted by lncRNAs were mainly associated with the immune regulation, Staphylococcus aureus infection and B cell receptor signalling pathways. The lncRNA-miRNA-mRNA coexpression network contained 265 network pairs comprising 55 dysregulated lncRNAs, 11 miRNAs, and 74 mRNAs. Conservation analysis of the differentially expressed lncRNAs between familial AI patients with NCSTN mutation and Ncstn keratinocyte-specific knockout (NcstnΔKC) mice identified 6 lncRNAs with sequence conservation; these lncRNAs may participate in apoptosis, proliferation, and skin barrier function.

CONCLUSIONS

These findings provide a direction for exploring the regulatory mechanisms underlying the progression of familial AI patients with NCSTN mutation.

Long non-coding RNAs and melanoma: From diagnosis to therapy

Although extremely rare, malignant melanoma is the deadliest type of skin malignancy with the inherent capability to invade other organs and metastasize to distant tissues. In 2021, it was estimated that approximately 106,110 patients may have received the diagnosis of melanoma, with a mortality rate of 7180. Surgery remains the common choice for treatment in patients with melanoma. Despite many advances in the treatment of melanoma, some patients, such as those who have received cytotoxic chemotherapeutic and immunotherapic agents, a significant number of patients may show inadequate treatment response following initiating these treatments. Non-coding RNAs, including lncRNAs, have become recently popular and attracted the attention of many researchers to make new insights into the pathogenesis of many diseases, particularly malignancies. LncRNAs have been thoroughly investigated in multiple cancers such as melanoma and have been shown to play a major role in regulating various physiological and pathological cellular processes. Considering their core regulatory function, these non-coding RNAs may be appropriate candidates for melanoma patients' diagnosis, prognosis, and treatment. In this review, we will cover all the current literature available for lncRNAs in melanoma and will discuss their potential benefits as diagnostic and/or prognostic markers or potent therapeutic targets in the treatment of melanoma patients.

The role of lncRNAs in the tumor microenvironment and immunotherapy of melanoma

Melanoma is one of the most lethal tumors with highly aggressive and metastatic properties. Although immunotherapy and targeted therapy have certain therapeutic effects in melanoma, a significant proportion of patients still have drug resistance after treatment. Recent studies have shown that long noncoding RNAs (lncRNAs) are widely recognized as regulatory factors in cancer. They can regulate numerous cellular processes, including cell proliferation, metastasis, epithelial-mesenchymal transition (EMT) progression and the immune microenvironment. The role of lncRNAs in malignant tumors has received much attention, whereas the relationship between lncRNAs and melanoma requires further investigation. Our review summarizes tumor suppressive and oncogenic lncRNAs closely related to the occurrence and development of melanoma. We summarize the role of lncRNAs in the immune microenvironment, immunotherapy and targeted therapy to provide new targets and therapeutic methods for clinical treatment.

RUNX Proteins as Epigenetic Modulators in Cancer

RUNX proteins are highly conserved in metazoans and perform critical functions during development. Dysregulation of RUNX proteins through various molecular mechanisms facilitates the development and progression of various cancers, where different RUNX proteins show tumor type-specific functions and regulate different aspects of tumorigenesis by cross-talking with different signaling pathways such as Wnt, TGF-β, and Hippo. Molecularly, they could serve as transcription factors (TFs) to activate their direct target genes or interact with many other TFs to modulate chromatin architecture globally. Here, we review the current knowledge on the functions and regulations of RUNX proteins in different cancer types and highlight their potential role as epigenetic modulators in cancer.

Long Non-Coding RNA CASC2 Functions as A Tumor Suppressor in Colorectal Cancer via Modulating The miR-18a-5p/BTG3 Pathway

OBJECTIVE

Reportedly, long non-coding RNA (lncRNA) cancer susceptibility candidate 2 (CASC2) is involved in regulating colorectal cancer (CRC) progression. However, the function and detailed downstream mechanism of CASC2 in CRC progression are not fully elucidated. The aim of the study was to investigate the potential function and molecular mechanism of CASC2 in CRC progression.

MATERIALS AND METHODS

In this experimental study, quantitative real-time polymerase chain reaction (qRT-PCR) was adopted to probe CASC2, microRNA-18a-5p (miR-18a-5p) and B cell translocation gene 3 (BTG3) mRNA expression in CRC tissues and cell lines. After CASC2 was overexpressed in Colo-678 and HCT116 cell lines, methylthiazol tetrazolium (MTT) and 5-bromo-2'-deoxyuridine (BrdU) assays were employed to examine the proliferation of CRC cells. Transwell migration and invasion assays were executed to evaluate the metastatic potential of CRC cells. The targeting relationships among CASC2, miR-18a-5p and BTG3 were validated by dual luciferase reporter gene assay. Western blot assay was applied to examine the regulatory effects of CASC2 and miR-18a-5p on BTG3 protein expression.

RESULTS

CASC2 was decreased in CRC tissues and cell lines, and its low expression in CRC tissues was associated with larger tumor size and lymph node metastasis. CASC2 overexpression restrained proliferative, migrative and invasive capabilities of CRC cells. CASC2 could function as a molecular sponge for miR-18a-5p and repress the expression of miR-18a-5p. Furthermore, the inhibitory effects of CASC2 on the malignant phenotypes of CRC cells was counteracted by miR-18a-5p mimics. Additionally, CASC2 could positively regulate BTG3 expression via suppressing miR-18a-5p.

CONCLUSION

CASC2 inhibits CRC development by suppressing miR-18a-5p and raising BTG3 expression.

Sevoflurane induces microRNA-18a to delay rat neurodevelopment via suppression of the RUNX1/Wnt/β-catenin axis

Sevoflurane anesthesia is reported to repress neurogenesis of neural stem cells (NSCs), thereby affecting the brain development, but the underlying mechanism of sevoflurane on the proliferation of NSCs remains unclear. Thus, this study aims to discern the relationship between sevoflurane and NSC proliferation. Bioinformatics tools were employed to predict the expression of microRNA-18a (miR-18a) in 9-day-old neonatal rat hippocampal tissues after sevoflurane treatment and the downstream genes of miR-18a, followed by a series of assays to explore the relationship among miR-18a, runt related transcription factor 1 (RUNX1), and β-catenin in the hippocampal tissues. NSCs were isolated from the hippocampal tissues and subjected to gain-/loss-of-function assays to investigate the interactions among miR-18a, RUNX1, and β-catenin in NSCs and their roles in NSC development. Bioinformatics analysis and experimental results confirmed high expression of miR-18a in rat hippocampal tissues and NSCs after sevoflurane treatment. Next, we found that miR-18a downregulated RUNX1 expression, while RUNX1 promoted NSC proliferation by activating the Wnt/β-catenin signaling pathway. The behavioral experiments also showed that sevoflurane caused nerve injury in rats, whilst RUNX1 overexpression protected rat neurodevelopment. Our findings uncovered that sevoflurane attenuated NSC proliferation via the miR-18a-meidated RUNX1/Wnt/β-catenin pathway, thereby impairing rat neurodevelopment.

Long Noncoding RNA CASC2 Facilitated Wound Healing through miRNA-155/HIF-1α in Diabetic Foot Ulcers

Diabetic foot ulcers (DFU) are among the serious complications which are closely linked to diabetes mellitus. However, there is still a lack of accurate and effective standard prevention and treatment programs for DFU. In this manuscript, we have investigated the function of lncRNA cancer susceptibility candidate 2 (CASC2)/miR-155/hypoxia-inducible factor 1-alpha (HIF-1α) in the wound healing of DFU. We have analyzed lncRNA CASC2`s expression in the marginal tissues of ulcers in patients and mice with DFU. Additionally, the interaction relationship and mechanism between lncRNA CASC2, miR-155, and HIF-1α were determined, which proved the effects of lncRNA CASC2/miR-155/HIF-1α on fibroblasts apoptosis, proliferation, and migration. According to our study, the lncRNA CASC2's expression was low in the tissues of ulcers of DFU mice and patients. lncRNA CASC2's overexpression promoted fibroblasts migration, proliferation, and inhibited apoptosis and was beneficial for the healing of wounds, preferably in the DFU mice. In addition, lncRNA CASC2 directly targets miR-155 and HIF-1α functions as miR-155's target gene. Overexpression of miR-155 abrogated the function of lncRNA CASC2. Similarly, HIF-1α's inhibition has reversed the effect of miR-155 downregulation on fibroblasts. In general, overexpression of lncRNA CASC2 facilitated wound healing through miR-155/HIF-1α in DFU.

YY1-induced long non-coding RNA small nucleolar RNA host gene 8 promotes the tumorigenesis of melanoma via the microRNA-656-3p/SERPINE1 mRNA binding protein 1 axis

Long non-coding (lnc) RNA serves a vital role in the cellular processes of carcinoma. This study aimed to explore the accurate mechanism underlying lncRNA small nucleolar RNA host gene 8 (SNHG8) in melanoma. In this study, lncRNA SNHG8 expression were upregulated in melanoma tissues and cells, and lncRNA SNHG8 knockdown reduced melanoma cell viability, migration and invasion. Moreover, lncRNA SNHG8 expression could be induced by transcription factor YY1. In addition, we found that miR-656 could directly bind to lncRNA SNHG8 and SERPINE1 mRNA binding protein 1 (SERBP1). Rescue assays indicated that miR-656 overexpression inhibited the aforementioned cellular activities in melanoma cells, which were reversed by SERBP1 overexpression. In conclusion, this work elucidated that YY1-induced upregulation of lncRNA SNHG8 boosted the development of melanoma via the miR-656-3p/SERBP1 axis, providing a novel therapeutic strategy for melanoma treatment.

The pleiotropic roles of circular and long noncoding RNAs in cutaneous melanoma

Cutaneous melanoma (CM) is a very aggressive disease, often characterized by unresponsiveness to conventional therapies and high mortality rates worldwide. The identification of the activating BRAFV600 mutations in approximately 50% of CM patients has recently fueled the development of novel small-molecule inhibitors that specifically target BRAFV600 -mutant CM. In addition, a major progress in CM treatment has been made by monoclonal antibodies that regulate the immune checkpoint inhibitors. However, although target-based therapies and immunotherapeutic strategies have yielded promising results, CM treatment remains a major challenge. In the last decade, accumulating evidence points to the aberrant expression of different types of noncoding RNAs (ncRNAs) in CM. While studies on microRNAs have grown exponentially leading to significant insights on CM biology, the role of circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) in this tumor is less understood, and much remains to be discovered. Here, we summarize and critically review the available evidence on the molecular functions of circRNAs and lncRNAs in BRAFV600 -mutant CM and CM immunogenicity, providing recent updates on their functional role in targeted therapy and immunotherapy resistance. In addition, we also include an evaluation of several algorithms and databases for prediction and validation of circRNA and lncRNA functional interactions.

lncRNA GAS5, as a ceRNA, inhibits the proliferation of diffuse large B‑cell lymphoma cells by regulating the miR‑18a‑5p/RUNX1 axis

Diffuse large B-cell lymphoma (DLBCL) is a common and fatal malignant tumor caused by B-lymphocytes. Long non-coding RNA (lncRNA) GAS5 (growth arrest specific 5) has been reported to function as a tumor suppressor gene, and is differentially expressed in DLBCL. The present study aimed to explore the potential mechanisms of action of lncRNA GAS5 in the proliferation of DLBCL cells. The expression levels of GAS5, miR-18a-5p and Runt-related transcription factor 1 (RUNX1) in DLBCL cell lines were detected using reverse transcription-quantitative polymerase chain reaction, and their effects on cell proliferation, the cell cycle and apoptosis were determined using 5-ethynyl-2′-deoxyuridine assay and flow cytometry. Dual-luciferase reporter and RNA pull-down assays were used to evaluate the interaction between GAS5 and miR-18a-5p, or between miR-18a-5p and RUNX1. Chromatin immunoprecipitation assay was used to identify the interaction between RUNX1 and BAX. The expression levels of GAS5 and RUNX1 were downregulated; however, miR-18a-5p expression was upregulated in the DLBCL cell lines compared with the normal controls. GAS5 directly interacted with miR-18a-5p by acting as a competing endogenous RNA (ceRNA) and reversed the low expression of RUNX1 induced by miR-18a-5p. Additionally, the knockdown of RUNX1 reversed the inhibitory effects of GAS5 on the proliferation and cell cycle G1 arrest, and its promoting effects on the apoptosis of OCI-Ly3 and TMD8 cells. Moreover, RUNX1 enhanced BAX expression by directly binding to the BAX promoter. On the whole, the present study demonstrates that GAS5 functions as a ceRNA, inhibiting DLBCL cell proliferation by sponging miR-18a-5p to upregulate RUNX1 expression. These findings may provide a potential therapeutic strategy for DLBCL.

miR-18a-5p Facilitates Malignant Progression of Head and Neck Squamous Cell Carcinoma Cells via Modulating SORBS2

This study attempted to investigate possible molecular mechanism and role of miR-18a-5p in head and neck squamous cell carcinoma (HNSCC). Differential miRNAs and their possible targets were analyzed through TCGA database. By conducting qRT-PCR, miR-18a-5p was tested to be increased and SORBS2 was assessed to be downregulated in HNSCC cells. CCK-8, Transwell, and flow cytometry assays disclosed that miR-18a-5p facilitated HNSCC cell proliferation, migration, and invasion and repressed cell apoptosis. By dual-luciferase reporter gene assay, it was verified that miR-18a-5p had binding sites into SORBS2. Rescue experiments displayed that forced expression of SORBS2 restored the impact of miR-18a-5p overexpression on HNSCC cells. Collectively, our research preliminarily identified the promotion effect of miR-18a-5p/SORBS2 axis on malignant phenotypes of HNSCC cells. Our findings may provide a preclinical reference for HNSCC treatment.

MicroRNA-18a-5p represses scar fibroblast proliferation and extracellular matrix deposition through regulating Smad2 expression

The aim of the present study was to investigate the expression and role of microRNA-18a-5p (miR-18a-5p) during the formation of hypertrophic scar (HS), and to further explore the molecular mechanisms involved. Downregulation of miR-18a-5p in HS tissues and human HS fibroblasts (hHSFs) was detected by reverse transcription-quantitative polymerase chain reaction. The binding sites between miR-18a-5p and the 3'-untranslated region of SMAD family member 2 (Smad2) were predicted by TargetScan and confirmed by dual-luciferase reporter assay. To investigate the role of miR-18a-5p in HS formation, the effects of miR-18a-5p downregulation or upregulation on hHSFs were subsequently determined. Cell proliferation was detected by an MTT assay, while cell apoptosis was measured by flow cytometry. In addition, the protein expression levels of Smad2, Collagen I (Col I) and Col III were examined by western blot assay. The findings indicated that miR-18a-5p downregulation in hHSFs significantly promoted the cell proliferation, decreased cell apoptosis and enhanced the expression levels of Smad2, Col I and Col III protein and mRNA, whereas miR-18a-5p upregulation in hHSFs exerted opposite effects. Notably, the effects of miR-18a-5p upregulation on hHSFs were eliminated by Smad2 upregulation. In conclusion, the data indicated that miR-18a-5p was downregulated during HS formation, and its upregulation repressed scar fibroblast proliferation and extracellular matrix deposition by targeting Smad2. Therefore, miR-18a-5p may serve as a novel therapeutic target for the treatment of HS.

The Functional Role of Long Non-Coding RNAs in Melanoma

Melanoma is the most lethal skin cancer, with increasing incidence worldwide. The molecular events that drive melanoma development and progression have been extensively studied, resulting in significant improvements in diagnostics and therapeutic approaches. However, a high drug resistance to targeted therapies and adverse effects of immunotherapies are still a major challenge in melanoma treatment. Therefore, the elucidation of molecular mechanisms of melanomagenesis and cancer response to treatment is of great importance. Recently, many studies have revealed the close association of long noncoding RNAs (lncRNAs) with the development of many cancers, including melanoma. These RNA molecules are able to regulate a plethora of crucial cellular processes including proliferation, differentiation, migration, invasion and apoptosis through diverse mechanisms, and even slight dysregulation of their expression may lead to tumorigenesis. lncRNAs are able to bind to protein complexes, DNA and RNAs, affecting their stability, activity, and localization. They can also regulate gene expression in the nucleus. Several functions of lncRNAs are context-dependent. This review summarizes current knowledge regarding the involvement of lncRNAs in melanoma. Their possible role as prognostic markers of melanoma response to treatment and in resistance to therapy is also discussed.

Pathogenic roles of long noncoding RNAs in melanoma: Implications in diagnosis and therapies

Melanoma is one of the most dangerous types of cutaneous neoplasms, which are pigment-producing cells of neuroectodermal origin found all over the body. A great deal of research is focused on the mechanisms of melanoma to promote better diagnostic and treatment options for melanoma in its advanced stages. The progression of melanoma involves alteration in different levels of gene expression. With the successful implementation of next-generation sequencing technology, an increasing number of long noncoding RNAs (lncRNAs) sequences have been discovered, and a significant number of them have phenotypic effects in both in vitro and in vivo studies, implying that they play an important role in the occurrence and progression of human cancers, particularly melanoma. A number of evidence indicated that lncRNAs are important regulators in tumor cell proliferation, invasion, apoptosis, immune escape, energy metabolism, drug resistance, epigenetic regulation. To better understand the role of lncRNAs in melanoma tumorigenesis, we categorize melanoma-associated lncRNAs according to their cellular functions and associations with gene expression and signaling pathways in this review. Based on the mechanisms of lncRNA, we discuss the possibility of lncRNA-target treatments, and the application of liquid biopsies to detect lncRNAs in melanoma diagnosis and prognosis.

FBXL19‑AS1 promotes the progression of nasopharyngeal carcinoma by acting as a competing endogenous RNA to sponge miR‑431 and upregulate PBOV1

Long non‑coding RNAs (lncRNAs) have been shown to function as crucial regulators in the progression of various types of cancer, including nasopharyngeal carcinoma (NPC). The aim of the present study was to investigate the mechanisms underlying the role of the FBXL19‑AS1/microRNA (miR)‑431/prostate and breast cancer overexpressed 1 (PBOV1) axis in the progression of NPC. The expression levels of FBXL19‑AS1, miR‑431 and PBOV1 were assessed by reverse transcription‑quantitative PCR. The Cell Counting Kit‑8 assay was utilized to detect cell viability. Cell migration and invasion were determined using a Transwell assay. The associations between FBXL19‑AS1 and miR‑431 or miR‑431 and PBOV1 were verified via bioinformatics analysis, dual‑luciferase and RNA‑binding protein immunoprecipitation assays. It was demonstrated that the expression levels of FBXL19‑AS1 and PBOV1 were upregulated in NPC tissues and cells, whereas miR‑431 expression was downregulated. FBXL19‑AS1 directly interacted with miR‑431. FBXL19‑AS1 silencing inhibited the viability, migration and invasion of C666‑1 and SUNE1 cells, whereas these effects could be alleviated by suppressing miR‑431. miR‑431 could target the 3'‑untranslated region of PBOV1. Overexpression of PBOV1 neutralized the miR‑431‑mediated suppression of NPC progression. Moreover, FBXL19‑AS1 could regulate PBOV1 by sponging miR‑431 in NPC cells. In conclusion, the lncRNA FBXL19‑AS1 accelerated NPC progression via the miR‑431/PBOV1 axis, suggesting that it may serve as a potential therapeutic target for patients with NPC.

miR-18a-5p Targets FBP1 to Promote Proliferation, Migration, and Invasion of Liver Cancer Cells and Inhibit Cell Apoptosis

Liver cancer is one of the most aggressive malignant tumors. It is significant to understand the molecular mechanism of liver cancer cells to develop new treatment plans. Studies have identified that FBP1 serves as a cancer inhibitor gene. To research the effect mechanism of FBP1 in liver cancer cells, bioinformatics analysis was performed to study its expression in liver cancer tissue. Survival analysis was also performed. Moreover, starBase database was applied to predict upstream regulatory genes of FBP1. Dual-luciferase assay was performed to testify their targeted relationship. The mRNA and protein expression levels of FBP1 in liver cancer cells were detected by qRT-PCR and western blot, respectively. Cell viability was analyzed by CCK-8 assay. The migratory and invasive abilities of cells were analyzed by Transwell assay. The apoptosis of liver cancer cells was detected by flow cytometry. The results showed that the expression of FBP1 was downregulated in liver cancer tissue and cells. FBP1 low expression was correlated with the poor prognosis of patients. miR-18a-5p could inhibit FBP1 expression. Overexpression of FBP1 could inhibit the progression of liver cancer cells and promote cell apoptosis. Overexpressing miR-18a-5p could promote the progression of liver cancer cells and inhibit cell apoptosis. However, overexpressing FBP1 simultaneously could reverse the effect. miR-18a-5p and FBP1 are expected to be candidates for liver cancer treatment.

Aberrant expression of LncRNA CASC2 mediated the cell viability, apoptosis and autophagy of colon cancer cells by sponging miR-19a via NF-κB signaling pathway

Abnormal and rapid proliferation of colon cancer cells is a severe problem that can be regulated by non-coding RNAs. Thus, our study focused on effects of lncRNA CASC2 and miR-19a on colon cancer cells. Expressions of lncRNA CASC2, miR-19a, Bcl-2, Bax and NF-κB/p65 were examined by RT-qPCR. Cell viabilities were detected by CCK-8. A luciferase report assay was used for measuring binding conditions between lncRNA CASC2 and miR-19a. Western blotting was used to evaluate expression of LC3-I, LC3-II and p62 related to autophagy. Expression of lncRNA CASC2 lower in cancer cell lines and the overexpression reduced the cell viability of HT29 and SW480. Furthermore, Bcl-2 was suppressed by overexpressed lncRNA CASC2, while Bax was upregulated. LC3-Ⅰ and p62 were both inhibited, but LC3-Ⅱ was promoted. MiR-19a was predicted to bind lncRNA CASC2 and expressed higher in cancer cell lines. Overexpressed miR-19a reduced expression of lncRNA CASC2 and increased cell viability. This was repressed by upregulated lncRNA CASC2. Bcl-2 and Bax expression and proteins implicated in autophagy that are regulated by lncRNA CASC2 upregulation were reversed by miR-19a overexpression. NF-κB was upregulated in colon cancer cell lines, while inhibition of NF-κB reversed functions of lncRNA CASC2 and magnified roles of miR-19a. Our findings showed that lncRNA CASC2 inhibited cell viability in colon cancer cell lines and miR-19a reversed its functions through the NF-κB signalling pathway, suggesting that these could be factors in treating colon cancer in the future.

Regulation of RUNX proteins by long non-coding RNAs and circular RNAs in different cancers

RUNX proteins have been shown to behave as "double-edge sword" in wide variety of cancers. Discovery of non-coding RNAs has played linchpin role in improving our understanding about the post-transcriptional regulation of different cell signaling pathways. Several new mechanistic insights and distinct modes of cross-regulation of RUNX proteins and non-coding RNAs have been highlighted by recent research. In this review we have attempted to provide an intricate interplay between non-coding RNAs and RUNX proteins in different cancers. Better conceptual and mechanistic understanding of layered regulation of RUNX proteins by non-coding RNAs will be helpful in effective translation of the laboratory findings to clinically effective therapeutics.

Xmrks the Spot: Fish Models for Investigating Epidermal Growth Factor Receptor Signaling in Cancer Research

Studies conducted in several fish species, e.g., Xiphophorus hellerii (green swordtail) and Xiphophorus maculatus (southern platyfish) crosses, Oryzias latipes (medaka), and Danio rerio (zebrafish), have identified an oncogenic role for the receptor tyrosine kinase, Xmrk, a gene product closely related to the human epidermal growth factor receptor (EGFR), which is associated with a wide variety of pathological conditions, including cancer. Comparative analyses of Xmrk and EGFR signal transduction in melanoma have shown that both utilize STAT5 signaling to regulate apoptosis and cell proliferation, PI3K to modulate apoptosis, FAK to control migration, and the Ras/Raf/MEK/MAPK pathway to regulate cell survival, proliferation, and differentiation. Further, Xmrk and EGFR may also modulate similar chemokine, extracellular matrix, oxidative stress, and microRNA signaling pathways in melanoma. In hepatocellular carcinoma (HCC), Xmrk and EGFR signaling utilize STAT5 to regulate cell proliferation, and Xmrk may signal through PI3K and FasR to modulate apoptosis. At the same time, both activate the Ras/Raf/MEK/MAPK pathway to regulate cell proliferation and E-cadherin signaling. Xmrk models of melanoma have shown that inhibitors of PI3K and MEK have an anti-cancer effect, and in HCC, that the steroidal drug, adrenosterone, can prevent metastasis and recover E-cadherin expression, suggesting that fish Xmrk models can exploit similarities with EGFR signal transduction to identify and study new chemotherapeutic drugs.

Endothelial progenitor cells-derived exosomal microRNA-21-5p alleviates sepsis-induced acute kidney injury by inhibiting RUNX1 expression

The role of microRNA-21-5p (miR-21-5p) in sepsis-induced acute kidney injury (AKI) has been seldom discussed. Therefore, the objective of this present study was to investigate the mechanism of endothelial progenitor cells-derived exosomes (EPCs-exos) in sepsis-induced AKI via miR-21-5p/runt-related transcription factor 1 (RUNX1) axis. miR-21-5p was downregulated and RUNX1 was upregulated in the kidney of cecal ligation and puncture (CLP) rats, and miR-21-5p targeted RUNX1. Elevation of miR-21-5p improved renal function and renal tissue pathological damage, attenuated serum inflammatory response, as well as reduced apoptosis and oxidative stress response in renal tissues, and regulated endothelial glycocalyx damage marker proteins syndecan-1 and heparanase-1 in CLP rats. Overexpression of RUNX1 abolished the impacts of elevated miR-21-5p in CLP rats. Also, EPCs-exos upregulated miR-21-5p expression, and functioned similar to elevation of miR-21-5p for CLP rats. Downregulating miR-21-5p partially reversed the effects of EPCs-exos on sepsis-induced AKI. Collectively, our study suggests that EPCs release miR-21-5p-containing exosomes to alleviate sepsis-induced AKI through RUNX1 silencing.

Long Non-Coding RNA HOXA11-AS Modulates Proliferation, Apoptosis, Metastasis and EMT in Cutaneous Melanoma Cells Partly via miR-152-3p/ITGA9 Axis

Background

Long non-coding RNA homeobox A11 antisense RNA (HOXA11-AS) was showed to participate in the progression of different kinds of tumors, but the specific role of HOXA11-AS in cutaneous melanoma is not entirely unambiguous.

Methods

The levels of HOXA11-AS, microRNA-152-3p (miR-152-3p) and integrin alpha9 (ITGA9) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was detected via 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT), and apoptosis was measured by flow cytometry. The assessment of cell metastasis was performed by transwell migration and invasion assays. The protein levels were detected through Western blot. Dual-luciferase reporter assay was utilized to explore the target relationship among HOXA11-AS, miR-152-3p and ITGA9. The effect of HOXA11-AS on melanoma in vivo was investigated via xenograft experiment.

Results

HOXA11-AS and ITGA9 were up-regulated while miR-152-3p was down-regulated in melanoma. Knockdown of HOXA11-AS refrained cell proliferation, metastasis and epithelial-mesenchymal transition (EMT) but induced apoptosis in melanoma cells. HOXA11-AS targeted miR-152-3p and overexpression of HOXA11-AS mitigated the miR-152-3p-induced effects on melanoma cellular behaviors. ITGA9 was a target of miR-152-3p and miR-152-3p inhibitor relieved the repression on proliferation, metastasis and EMT while elevation on apoptosis caused by si-ITGA9 via elevating ITGA9. HOXA11-AS knockdown restrained ITGA9 expression via up-regulating miR-152-3p. Suppression of HOXA11-AS inhibited melanoma progression in part through increasing miR-152-3p and decreasing ITGA9 expression in vivo.

Conclusion

HOXA11-AS modulated proliferation, apoptosis, metastasis and EMT in melanoma cells by regulating miR-152-3p/ITGA9 axis in part. HOXA11-AS could promote melanoma development and be used as a promising biomarker in the diagnosis and treatment for cutaneous melanoma.

Comprehensive Review on the Clinical Relevance of Long Non-Coding RNAs in Cutaneous Melanoma

Cutaneous melanoma is considered a rare tumor, although it is one of the most common cancers in young adults and its incidence has risen in the last decades. Targeted therapy, with BRAF and MEK inhibitors, and immunotherapy revolutionized the treatment of metastatic melanoma but there is still a considerable percentage of patients with primary or acquired resistance to these therapies. Recently, oncology researchers directed their attention at the role of long non-coding RNAs (lncRNAs) in different types of cancers, including melanoma. lncRNAs are RNA transcripts, initially considered "junk sequences", that have been proven to have a crucial role in the fine regulation of physiological and pathological processes of different tissues. Furthermore, they are more expressed in tumors than protein-coding genes, constituting perfect candidates either as biomarkers (diagnostic, prognostic, predictive) or as therapeutic targets. In this work, we reviewed all the literature available for lncRNA in melanoma, elucidating all the potential roles in this tumor.

Integration of transcriptome and cistrome analysis identifies RUNX1-target genes involved in pancreatic cancer proliferation

The extremely high proliferation rate of tumor cells contributes to pancreatic cancer (PC) progression. Runt-related transcription factor 1(RUNX1), a key factor in hematopoiesis that was correlated with tumor progression. However, the role of RUNX1 in PC proliferation was still unclear. We found that RUNX1 was significantly upregulated in PC tissues and its expression was negatively associated with prognosis of PC patients in a multicenter analysis according to immunohistochemical (IHC). RUNX1 downregulation in PC resulted in a significantly reduced cell proliferation rate, which was consistent with in vivo subcutaneous tumor formation assay results. RNA-seq and ChIP-seq results revealed that a portion of target genes, including HAP1, GPRC5B, PTPN21, VHL and EN2, were regulated by RUNX1, a finding successfully validated by ChIP-qPCR, qRT-PCR and Western blot. Subsequently, IHC and proliferation assays showed these target genes to be dysregulated in PC, affecting tumor growth. Our data suggest that RUNX1 plays an oncogenic role in tumor proliferation and is a potential prognostic biomarker and therapeutic target for PC.

Good or not good: Role of miR-18a in cancer biology

miR-18a is a member of primary transcript called miR-17-92a (C13orf25 or MIR17HG) which also contains five other miRNAs: miR-17, miR-19a, miR-20a, miR-19b and miR-92a. This cluster as a whole shows specific characteristics, where miR-18a seems to be unique. In contrast to the other members, the expression of miR-18a is additionally controlled and probably functions as its own internal controller of the cluster. miR-18a regulates many genes involved in proliferation, cell cycle, apoptosis, response to different kinds of stress, autophagy and differentiation. The disturbances of miR-18a expression are observed in cancer as well as in different diseases or pathological states. The miR-17-92a cluster is commonly described as oncogenic and it is known as 'oncomiR-1', but this statement is a simplification because miR-18a can act both as an oncogene and a suppressor. In this review we summarize the current knowledge about miR-18a focusing on its regulation, role in cancer biology and utility as a potential biomarker.

miR-18a expression in basal cell carcinoma and regulatory mechanism on autophagy through mTOR pathway

BACKGROUND

Basal cell carcinoma (BCC) is the most common form of skin carcinoma.

AIM

To investigate the function of key micro(mi)RNAs and to explore the potential molecular mechanisms involved in BCC.

METHODS

The microarray dataset GSE34535, which comprises seven BCC samples and seven control samples, was downloaded from the Gene Expression Omnibus database. Differentially expressed miRNAs (DE-miRNAs) were identified. We collected tissue samples from 20 patients with BCC and 20 healthy controls (HCs), to compare the miR-18a expression in their tissue samples. Expression of miR-18a in A431 and HaCaT cells was also assayed. Following this, we upregulated and downregulated miR-18a expression in A431 cells to examine the effects on cell proliferation, migration and apoptosis. To further investigate the relative mechanism, the proteins LC3, Beclin 1, Akt and mammalian target of rapamycin (mTOR) were examined by quantitative real-time PCR and Western blotting. For further verification, we examined the expression of LC3 in the 20 BCC and 20 HC tissue samples.

RESULTS

In total, 19 DE-miRNAs (13 upregulated and 6 downregulated) that were common to the BCC and HC groups were identified. Levels of miR-18a were about three-fold higher in BCC tissues and A431 cells compared with their respective control groups. In vitro, downregulation of miR-18a was shown to inhibit cell proliferation and activate autophagy via the Akt/mTOR signalling pathway, while upregulation of miR-18a promoted proliferation of these cells. LC3 was decreased in BCC compared with HC tissue samples.

CONCLUSIONS

Our data support an oncogenic role of miR-18a through a novel Akt/mTOR/Beclin 1/LC3 axis, and suggest that the antitumour effects of miR-18a inhibitor may make it suitable for BCC therapy.

Long noncoding RNA CASC2 inhibits ox-LDL-mediated vascular smooth muscle cells proliferation and migration via the regulation of miR-532-3p/PAPD5

Background

Studies have demonstrated that long noncoding RNAs (lncRNAs) have essential impacts on the development of atherosclerosis (AS). This study aimed to identify the role and functional mechanism of lncRNA CASC2 in the development and migration of vascular smooth muscle cells (VSMCs).

Method

The serum of 40 pairs of AS patients and healthy volunteers were collected and the expression of CASC2 was evaluated. qRT-PCR and western blotting were carried out to examine the expression levels of at mRNA and protein level, repectively. Cell proliferation assay, colony formation assay, transwell migration assay, dual-luciferase reporter assay, and wound healing assay were conducted to evaluate cell proliferation, colony formation, migration, transcription, targeting, and self-restoration.

Results

The expression levels of CASC2 were decreased, while the expression levels of miR-532-3p were elevated in AS patient samples and VSMCs. Overexpression of CASC2 inhibited the proliferation and migration of VSMCs and enhanced cell apoptosis. CASC2 inhibited the expression of miR-532-3p, and inversely upregulated the expression of PAPD5, which was a target of miR-532-3p. In addition, knockdown of miR-532-3p-mimic and PAPD5 could attenuate the impact of overexpression of CASC2 on proliferation, migration, and apoptosis in ox-LDL-VSMCs.

Conclusion

CASC2 suppressed cell reproduction and promoted cell apoptosis by regulating the miR-532-3p/PAPD5 axis in ox-LDL-mediated VSMCs. This might be important for AS therapeutics.

Inflammation and DNA methylation coregulate the CtBP-PCAF-c-MYC transcriptional complex to activate the expression of a long non-coding RNA CASC2 in acute pancreatitis

Long non-coding RNAs (lncRNAs) are emerging as important regulators involved in the pathogenesis of many diseases. However, it is still unknown if they contribute to the occurrence of acute pancreatitis (AP). Here, we identified a lncRNA CASC2 (Cancer Susceptibility Candidate 2) was significantly upregulated in the pancreatic tissues from AP patients. Knockdown or overexpression of CASC2 in vitro could specifically repress or induce the expression of two proinflammatory cytokines including IL6 (Interleukin 6) and IL17, respectively. Changing the expression levels of several transcription factors that were predicted to bind to the promoter of CASC2, we found c-MYC could specifically regulate the expression of CASC2. Using immunoprecipitation, mass spectrometry, and co-immunoprecipitation assays, we proved that c-MYC assembled a transcriptional complex with PCAF (p300/CBP-associated Factor) and CtBP1/2 (C-terminal Binding Protein 1 and 2), terming as the CtBP-PCAF-c-MYC (CPM) complex. Further investigation revealed that CtBPs were amplified in the pancreatic tissues from AP patients and they functioned as coactivators to induce the expression of CASC2 and thus led to the upregulation of IL6 and IL17. Moreover, we identified that decreased DNA methylation levels in the promoters of CtBPs and inflammatory stimuli coactivated the expression of CtBPs. Collectively, we identified a new signaling pathway in which DNA methylation and inflammatory stimuli coregulate the CPM complex to activate CASC2 expression, whose induction further activates the expression of IL6 and IL17, eventually aggravating inflammation response and causing the pathology of AP.

Long noncoding RNA WDFY3-AS2 suppresses tumor progression by acting as a competing endogenous RNA of microRNA-18a in ovarian cancer

Ovarian cancer (OC) is a fatal cancer in women, mainly due to its aggressive nature and poor survival rate. The lncRNA-miRNA-mRNA (long noncoding RNA-microRNA-messenger RNA) interaction is promising biomarkers for the improving prognosis of OC. Therefore, we explored the regulatory mechanism of WDFY3-AS2/miR-18a/RORA axis involved in the biological activities of OC cells. Microarray analysis predicted differentially expressed lncRNA, miRNA, and mRNA related to OC, followed by investigating the relationship among them. The expression patterns of the identified lncRNA WDFY3-AS2, miR-18a, and RORA were measured in OC tissue and cells. Gain- and loss-of-function experiments were performed to characterize the effect of lncRNA WDFY3-AS2 on OC cells, as well as the involvement of miR-18a and RAR related orphan receptor A (RORA). The in vitro assays were validated by in vivo experiments. According to bioinformatics analysis, WDFY3-AS2 was speculated to affect OC by sponging miR-18a and modulating RORA. WDFY3-AS2 and RORA were underexpressed in OC, while miR-18a was highly expressed. Notably, WDFY3-AS2 acts as a competing endogenous RNA to sponge miR-18a and upregulate RORA. Upon overexpressing WDFY3-AS2 or inhibiting miR-18a, RORA expression was increased, thereby the OC cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) were suppressed, accompanied by enhanced apoptosis. In vivo experiments confirmed that the tumor growth was reduced in response to overexpressed WDFY3-AS2 or inhibited miR-18a. Taken together, the lncRNA WDFY3-AS2/miR-18a axis regulates the tumor progression of OC by targeting RORA, providing new insights for prevention and control of OC.

Long noncoding RNA CASC2 suppresses esophageal squamous cell carcinoma progression by increasing SOCS1 expression

Objective

Esophageal squamous cell carcinoma (ESCC) is one of the leading causes of cancer-related deaths worldwide. Emerging evidence suggests the involvement of long noncoding RNAs (lncRNAs) in tumorigenesis. LncRNA Cancer Susceptibility Candidate 2 (CASC2) has been demonstrated to act as a tumor suppressor contributing to the development and progression of several cancers. However, the functional significance and underlying mechanism of CASC2 in ESCC progression has not been well elucidated.

Methods

The expression levels of CASC2 in ESCC tissues were detected by qRT-PCR. CASC2 overexpression and knockdown models were established and used to investigate the functional role of CASC2 in ESCC cells. RIP, RNA pull-down and dual-luciferase assay was used to detect the association between CASC2 and miR-155. The interaction between CASC2 and Suppressor Of Cytokine Signaling 1 (SOCS1) was assessed by RIP and RNA pull-down assays.

Results

In the present study, we found that CASC2 was significantly downregulated in ESCC tissues and positively correlated with overall survival time of patients with ESCC. Functional assays demonstrated that CASC2 suppressed proliferation, migration and invasion, as well as enhanced drug sensitivity in ESCC cells. Mechanistically, CASC2 inhibited ESCC progression by upregulating the expression of SOCS1 via two different ways. CASC2 acted as competing endogenous RNA (ceRNA) for miR-155 to post-transcriptionally increase SOCS1 expression. On the other hand, CASC2 was capable of interacting with SOCS1 protein and suppressing its degradation.

Conclusion

Conclusively, these results demonstrated that CASC2 could exert as a tumor suppressive lncRNA in ESCC progression via regulating SOCS1.

LncRNA FER1L4 induces apoptosis and suppresses EMT and the activation of PI3K/AKT pathway in osteosarcoma cells via inhibiting miR-18a-5p to promote SOCS5

Previous studies have determined that long non-coding RNA (lncRNA) Fer-1-like protein 4 (FER1L4) is suppressed in osteosarcoma (OS) and inhibits the tumorigenesis in a variety of cancer. However, the precise biological of FER1L4 in OS has not been cleared. The aim of this study is to investigate the roles and potential mechanisms of FER1L4 in apoptosis and epithelial-mesenchymal transition (EMT) in OS. In the present study, the levels of FER1L4 were decreased significantly in OS tissues and cell lines compared with non-tumorous tissues or hFOB1.19. Knockdown of FER1L4 in OS cells decreased the apoptosis rate, but increased the OS cell proliferation, upregulated the expression levels of CD133 and Nanog, as well as promoted Twist1 expression, increased the N-cadherin and Vimentin expression. In turn, the opposite trends were observed upon overexpression of FER1L4. In addition, the expression of PI3K, p-AKT (Ser470) and p-AKT (Thr308) was upregulated by siFER1L4, while decreased upon overexpression of FER1L4. MicroRNA (miRNA) -18a-5p, an osteosarcoma-promoting miRNA which was suggested a target of FER1L4 in osteosarcoma, was identified to be a functional target of FER1L4 on the regulating of cell apoptosis and EMT, presently. The effects of FER1L4 overexpression on the markers of cell apoptosis, proliferation, EMT, and stemness and PI3K/AKT signaling were all reversed by miR-18a-5p upregulation. Furthermore, the suppressor of cytokine signaling 5 (SOCS5) was confirmed a target gene of miR-18a-5p by luciferase gene reporter assay and SOCS5 suppression by miR-18a-5p attenuated the effects of FER1L4 overexpression on the OS cells apoptosis and the expressed levels of PI3K, AKT, Twist1, N-cadherin and Vimentin. In conclusion, our data indicated thatthe overexpression of FER1L4 promoted apoptosis and inhibited the EMT markers expression and PI3K/AKT signaling pathway activation in OS cells via downregulating miR-18a-5p to promote SOCS5.

Oncogenic role of long non-coding RNA SNHG12 in gastric cancer cells by targeting miR-16

The long non-coding RNA small nucleolar RNA host gene 12 (SNHG12) has recently been reported to have an oncogenic role in gastric cancer (GC), but the molecular mechanisms remain largely elusive. In the present study, it was observed that SNHG12 was significantly upregulated in GC tissues and cell lines. High expression of SNHG12 was associated with GC progression and poor prognosis of patients. Knockdown of SNHG12 markedly inhibited the proliferation and migration of the BGC823 and HGC27 GC cell lines. MicroRNA (miR)-16 was identified as a target of SNHG12, and its expression was negatively regulated by SNHG12 in BGC823 and HGC27 cells. In addition, the expression of miR-16 was significantly decreased in GC tissues and cell lines, and inversely associated with the expression of SNHG12 in GC tissues. Furthermore, knockdown of miR-16 impaired the inhibitory effects on GC cell proliferation and migration induced by downregulation of SNHG12. In conclusion, the present study demonstrates that inhibition of SNHG12 suppresses GC cell proliferation and migration by modulation of miR-16 expression, and thus suggests that the SNHG12/miR-16 interaction may be used as a promising target for GC treatment.

Knockdown of lncRNA-UCA1 inhibits the proliferation and migration of melanoma cells through modulating the miR-28-5p/HOXB3 axis

Long non-coding RNA urothelial carcinoma-associated 1 (UCA1) functions as an oncogene in different human cancers, including melanoma. However, the molecular mechanism of UCA1 underlying melanoma progression still remains largely unknown. In the present study, reverse transcription quantitative polymerase chain reaction and western blot analyses were used to examine the mRNA and protein expression levels, respectively. Cell Counting Kit-8 and wound healing assays were conducted to study cell proliferation and migration, respectively. A luciferase reporter assay was used to confirm the targeting relationship. It was demonstrated that UCA1 expression was increased in melanoma tissues and cell lines. In addition, UCA1 expression was higher in melanoma tissues at stage III-IV than in tissues at stage I-II. Inhibition of UCA1 expression markedly reduced melanoma cell proliferation and migration. Further investigation revealed that UCA1 functioned in melanoma cells through directly binding with microRNA (miR)-28-5p. The expression of miR-28-5p was significantly reduced in melanoma tissues and had an inverse correlation with UCA1 expression. In addition, miR-28-5p expression was higher in melanoma tissues at advanced stages than in stage I-II tissues. Furthermore, homeobox (HOX)B3 was identified as a target gene of miR-28-5p in melanoma cells, and HOXB3 overexpression reversed the suppressive effects of UCA1 downregulation on melanoma cell proliferation and migration. Finally, HOXB3 was upregulated in melanoma tissues compared with its expression in adjacent tissues, and HOXB3 expression was increased in melanoma tissues at advanced stages. Taken together, the regulatory network of the UCA1/miR-28-5p/HOXB3 axis in melanoma was demonstrated for the first time in the present study, expanding the understanding of the molecular mechanism underlying melanoma progression. Future studies may further confirm the function of this signaling pathway in vivo.

MicroRNA-18a promotes hepatocellular carcinoma proliferation, migration, and invasion by targeting Bcl2L10

BACKGROUND

Hepatocellular carcinoma (HCC) is known to feature several microRNA dysregulations. This study aimed to determine and investigate the prognostic value of microRNA (miRNA/miR)-18a and its role in regulating the progression of HCC.

METHODS

miR-18a expressions in human HCC tissues, pair-matched adjacent normal liver tissues as well as in HCC cell lines were determined by quantitative real-time PCR. The prognostic value of miR-18a was determined using Kaplan-Meier survival analysis and multivariable Cox regression assay. The ability of miR-18a in promoting HCC progression was verified in vitro.

RESULTS

miR-18a expressions in HCC tissues and cells were more than twice those of the normal control group (P<0.05). miR-18a expression was associated with the alpha-fetoprotein (AFP) level, TNM stage, tumor size, and intrahepatic vascular invasion (P<0.05). Kaplan- Meier survival analysis revealed that HCC patients with high expression of miR-18a possessed a more unfavorable prognosis (log-rank P<0.001). Overexpression of miR-18a promoted cell apoptosis and proliferation, induced S phase transition, as well as enhanced the migration and invasion ability of HCC cells. miR-18a was found to directly target the downstream molecule Bcl2L10. Furthermore, overexpressing Bcl2L10 was able to partly reverse the promoting effects of miR-18a on HCC cell progression.

CONCLUSION

miR-18a may serve as a prognostic biomarker of HCC as it is demonstrated to carry out a decisive role in HCC progression by promoting HCC cell invasion, migration, and proliferation through targeting Bcl2L10.

CASC2: An emerging tumour-suppressing long noncoding RNA in human cancers and melanoma

Deregulation of long noncoding RNAs (lncRNAs) has been implicated in tumourigenesis. Cancer Susceptibility Candidate 2 (CASC2) is a lncRNA downregulated in multiple cancer types, including endometrial, lung, gastric and colorectal cancers. CASC2 functions as a tumour-suppressive lncRNA though multiple mechanisms, such as sequestration of oncogenic microRNAs and repression of Wnt/β-catenin signalling. Pertinent to clinical practice, the use of CASC2 as a prognostic marker has been demonstrated in sporadic studies. These findings suggested that CASC2 might play an important role in human cancers and melanoma. More efforts are warranted to examine the function role of CASC2 in other cancer types. Further validation is also needed to promote its development to be a clinically utilizable prognostic biomarker.