LncRNA ST8SIA6-AS1 promotes hepatocellular carcinoma cell proliferation and resistance to apoptosis by targeting miR-4656/HDAC11 axis

ST8SIA6-AS1, a novel lncRNA star in liver cancer

Liver cancer is one of the most lethal gastrointestinal malignancies. Emerging evidence has underscored the pivotal role of long non-coding RNAs (lncRNAs) in tumorigenesis, with ST8SIA6-AS1 identified as a novel oncogenic lncRNA contributing to liver cancer progression. ST8SIA6-AS1 is consistently upregulated in hepatic cancer tissues and is strongly associated with unfavorable prognosis. Moreover, it demonstrates high diagnostic efficacy in detecting HCC. ST8SIA6-AS1 is involved in various cellular processes including proliferation, migration, and invasion, primarily through its function as a competing endogenous RNA (ceRNA), thereby facilitating hepatocarcinogenesis and disease advancement. This review provides a detailed examination of the molecular functions and regulatory mechanisms of ST8SIA6-AS1 in hepatocellular carcinoma (HCC) and highlights its potential as a promising biomarker for liver cancer, aiming to propel the development of innovative therapeutic strategies for HCC management.

Exploring non-coding RNA mechanisms in hepatocellular carcinoma: implications for therapy and prognosis

Hepatocellular carcinoma (HCC) is a significant contributor to cancer-related deaths in the world. The development and progression of HCC are closely correlated with the abnormal regulation of non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). Important biological pathways in cancer biology, such as cell proliferation, death, and metastasis, are impacted by these ncRNAs, which modulate gene expression. The abnormal expression of non-coding RNAs in HCC raises the possibility that they could be applied as new biomarkers for diagnosis, prognosis, and treatment targets. Furthermore, by controlling the expression of cancer-related genes, miRNAs can function as either tumor suppressors or oncogenes. On the other hand, lncRNAs play a role in the advancement of cancer by interacting with other molecules within the cell, which, in turn, affects processes such as chromatin remodeling, transcription, and post-transcriptional processes. The importance of ncRNA-driven regulatory systems in HCC is being highlighted by current research, which sheds light on tumor behavior and therapy response. This research highlights the great potential of ncRNAs to improve patient outcomes in this difficult disease landscape by augmenting the present methods of HCC care through the use of precision medicine approaches.

The role of CEMIP in cancers and its transcriptional and post-transcriptional regulation

CEMIP is a protein known for inducing cell migration and binding to hyaluronic acid. Functioning as a hyaluronidase, CEMIP primarily facilitates the breakdown of the extracellular matrix component, hyaluronic acid, thereby regulating various signaling pathways. Recent evidence has highlighted the significant role of CEMIP in different cancers, associating it with diverse pathological states. While identified as a biomarker for several diseases, CEMIP's mechanism in cancer seems distinct. Accumulating data suggests that CEMIP expression is triggered by chemical modifications to itself and other influencing factors. Transcriptionally, chemical alterations to the CEMIP promoter and involvement of transcription factors such as AP-1, HIF, and NF-κB regulate CEMIP levels. Similarly, specific miRNAs have been found to post-transcriptionally regulate CEMIP. This review provides a comprehensive summary of CEMIP's role in various cancers and explores how both transcriptional and post-transcriptional mechanisms control its expression.

Comparative Structure-Based Virtual Screening Utilizing Optimized AlphaFold Model Identifies Selective HDAC11 Inhibitor

HDAC11 is a class IV histone deacylase with no crystal structure reported so far. The catalytic domain of HDAC11 shares low sequence identity with other HDAC isoforms, which makes conventional homology modeling less reliable. AlphaFold is a machine learning approach that can predict the 3D structure of proteins with high accuracy even in absence of similar structures. However, the fact that AlphaFold models are predicted in the absence of small molecules and ions/cofactors complicates their utilization for drug design. Previously, we optimized an HDAC11 AlphaFold model by adding the catalytic zinc ion and minimization in the presence of reported HDAC11 inhibitors. In the current study, we implement a comparative structure-based virtual screening approach utilizing the previously optimized HDAC11 AlphaFold model to identify novel and selective HDAC11 inhibitors. The stepwise virtual screening approach was successful in identifying a hit that was subsequently tested using an in vitro enzymatic assay. The hit compound showed an IC50 value of 3.5 µM for HDAC11 and could selectively inhibit HDAC11 over other HDAC subtypes at 10 µM concentration. In addition, we carried out molecular dynamics simulations to further confirm the binding hypothesis obtained by the docking study. These results reinforce the previously presented AlphaFold optimization approach and confirm the applicability of AlphaFold models in the search for novel inhibitors for drug discovery.

Utilization of AlphaFold models for drug discovery: Feasibility and challenges. Histone deacetylase 11 as a case study

Histone deacetylase 11 (HDAC11), an enzyme that cleaves acyl groups from acylated lysine residues, is the sole member of class IV of HDAC family with no reported crystal structure so far. The catalytic domain of HDAC11 shares low sequence identity with other HDAC isoforms which complicates the conventional template-based homology modeling. AlphaFold is a neural network machine learning approach for predicting the 3D structures of proteins with atomic accuracy even in absence of similar structures. However, the structures predicted by AlphaFold are missing small molecules as ligands and cofactors. In our study, we first optimized the HDAC11 AlphaFold model by adding the catalytic zinc ion followed by assessment of the usability of the model by docking of the selective inhibitor FT895. Minimization of the optimized model in presence of transplanted inhibitors, which have been described as HDAC11 inhibitors, was performed. Four complexes were generated and proved to be stable using three replicas of 50 ns MD simulations and were successfully utilized for docking of the selective inhibitors FT895, MIR002 and SIS17. For SIS17, The most reasonable pose was selected based on structural comparison between HDAC6, HDAC8 and the HDAC11 optimized AlphaFold model. The manually optimized HDAC11 model is thus able to explain the binding behavior of known HDAC11 inhibitors and can be used for further structure-based optimization.

HDAC11: A novel target for improved cancer therapy

Histone deacetylase 11 (HDAC11) is a unique member of the histone deacetylase family that plays an important role in the regulation of gene expression and protein function. In recent years, research on the role of HDAC11 in tumors has attracted increasing attention. This review summarizes the current knowledge on the subcellular localization, structure, expression, and functions of HDAC11 in tumors, as well as the regulatory mechanisms involved in its network, including ncRNA and substrates. Moreover, we focus on the progress made in targeting HDAC11 to overcome tumor therapy resistance, and the development of HDAC11 inhibitors for cancer treatment. Collectively, this review provides comprehensive insights into the potential clinical implications of HDAC11 for cancer therapy.

Differentially expressed non-coding RNAs and their regulatory networks in liver cancer

The vast majority of human transcriptome is represented by various types of small RNAs with little or no protein-coding capability referred to as non-coding RNAs (ncRNAs). Functional ncRNAs include microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), which are expressed at very low, but stable and reproducible levels in a variety of cell types. ncRNAs regulate gene expression due to miRNA capability of complementary base pairing with mRNAs, whereas lncRNAs and circRNAs can sponge miRNAs off their target mRNAs to act as competitive endogenous RNAs (ceRNAs). Each miRNA can target multiple mRNAs and a single mRNA can interact with several miRNAs, thereby creating miRNA-mRNA, lncRNA-miRNA-mRNA, and circRNA-miRNA-mRNA regulatory networks. Over the past few years, a variety of differentially expressed miRNAs, lncRNAs, and circRNAs (DEMs, DELs, and DECs, respectively) have been linked to cancer pathogenesis. They can exert both oncogenic and tumor suppressor roles. In this review, we discuss the recent advancements in uncovering the roles of DEMs, DELs, and DECs and their networks in aberrant cell signaling, cell cycle, transcription, angiogenesis, and apoptosis, as well as tumor microenvironment remodeling and metabolic reprogramming during hepatocarcinogenesis. We highlight the potential and challenges in the use of differentially expressed ncRNAs as biomarkers for liver cancer diagnosis and prognosis.

Integrated analysis of multiple transcriptomic data identifies ST8SIA6‑AS1 and LINC01093 as potential biomarkers in HBV‑associated liver cancer

The mechanisms of long-non-coding RNAs (lncRNAs) in hepatitis B virus (HBV) infection-associated liver cancer remain largely unclear. Therefore, the aim of the present study was to investigate the regulatory mechanisms of lncRNAs in this disease. HBV-liver cancer related transcriptome expression profile data (GSE121248 and GSE55092) from the Gene Expression Omnibus database and survival prognosis information from The Cancer Genome Atlas (TCGA) database were obtained for analysis. The limma package was used to identify the overlapped differentially expressed RNAs (DERs), including DElncRNAs and DEmRNAs, in the GSE121248 and GSE55092 datasets. The screened optimized lncRNA signatures were used to develop a nomogram model based on the GSE121248 dataset, which was validated using the GSE55092 and TCGA datasets. A competitive endogenous RNA (ceRNA) network was constructed based on the screened prognosis-associated lncRNA signatures from TCGA dataset. In addition, the levels of specific lncRNAs were evaluated in HBV-infected human liver cancer tissues and cells, and Cell Counting Kit-8, ELISA and Transwell assays were performed to evaluate the effects of the lncRNAs in HBV-expressing liver cancer cells. A total of 535 overlapped DERs, including 30 DElncRNAs and 505 DEmRNAs, were identified in the GSE121248 and GSE55092 datasets. An optimized DElncRNA signature comprising 10 lncRNAs was used to establish a nomogram. ST8SIA6-AS1 and LINC01093 were identified as lncRNAs associated with HBV-liver cancer prognosis in TCGA dataset, and were applied to construct a ceRNA network. Reverse transcription-quantitative PCR analysis showed that ST8SIA6-AS1 was upregulated and LINC01093 was downregulated in HBV-infected human liver cancer tissues and HBV-expressing liver cancer cells compared with non-HBV-infected controls. ST8SIA6-AS1 knockdown and LINC01093 overexpression independently reduced the number of copies of HBV DNA, the levels of hepatitis B surface antigen and hepatitis B e antigen, as well as cell proliferation, migration and invasion. In summary, the present study identified ST8SIA6-AS1 and LINC01093 as two potential biomarkers that may be effective therapeutic targets for HBV-associated liver cancer.

ST8SIA6-AS1 contributes to hepatocellular carcinoma progression by targeting miR-142-3p/HMGA1 axis

Hepatocellular carcinoma (LIHC) accounts for 90% of all liver cancers and is a serious health concern worldwide. Long noncoding RNAs (lncRNAs) have been observed to sponge microRNAs (miRNAs) and participate in the biological processes of LIHC. This study aimed to evaluate the role of the ST8SIA6-AS1-miR-142-3p-HMGA1 axis in regulating LIHC progression. RT-qPCR and western blotting were performed to determine the levels of ST8SIA6-AS1, miR-142-3p, and HMGA1 in LIHC. The relationship between ST8SIA6-AS1, miR-142-3p, and HMGA1 was assessed using luciferase assay. The role of the ST8SIA6-AS1-miR-142-3p-HMGA1 axis was evaluated in vitro using LIHC cells. Expression of ST8SIA6-AS1 and HMGA1 was significantly upregulated, whereas that of miR-142-3p was markedly lowered in LIHC specimens and cells. ST8SIA6-AS1 accelerated cell growth, invasion, and migration and suppressed apoptosis in LIHC. Notably, ST8SIA6-AS1 inhibited HMGA1 expression by sponging miR-142-3p in LIHC cells. In conclusion, sponging of miR-142-3p by ST8SIA6-AS1 accelerated the growth of cells while preventing cell apoptosis in LIHC cells, and the inhibitory effect of miR-142-3p was abrogated by elevating HMGA1 expression. The ST8SIA6-AS1-miR-142-3p-HMGA1 axis represents a potential target for the treatment of patients with LIHC.

Long non-coding RNAs (lncRNAs) in hepatocellular carcinoma progression: Biological functions and new therapeutic targets

Liver is an important organ in body that performs vital functions such as detoxification. Liver is susceptible to development of cancers, and hepatocellular carcinoma (HCC) is among them. 75-85% of liver cancer cases are related to HCC. Therefore, much attention has been directed towards understanding factors mediating HCC progression. LncRNAs are epigenetic factors with more than 200 nucleotides in length located in both nucleus and cytoplasm and they are promising candidates in cancer therapy. Directing studies towards understanding function of lncRNAs in HCC is of importance. LncRNAs regulate cell cycle progression and growth of HCC cells, and they can also induce/inhibit apoptosis in tumor cells. LncRNAs affect invasion and metastasis in HCC mainly by epithelial-mesenchymal transition (EMT) mechanism. Revealing the association between lncRNAs and downstream signaling pathways in HCC is discussed in the current manuscript. Infectious diseases can affect lncRNA expression in mediating HCC development and then, altered expression level of lncRNA is associated with drug resistance and radio-resistance. Biomarker application of lncRNAs and their role in prognosis and diagnosis of HCC are also discussed to pave the way for treatment of HCC patients.

HDAC11, an emerging therapeutic target for metabolic disorders

Histone deacetylase 11 (HDAC11) is the only member of the class IV HDAC, and the latest member identified. It is highly expressed in brain, heart, kidney and some other organs, and located in mitochondria, cytoplasm and nuclei, depending on the tissue and cell types. Although studies in HDAC11 total knockout mice suggest its dispensable features for tissue development and life, it participates in diverse pathophysiological processes, such as DNA replication, tumor growth, immune regulation, oxidant stress injury and neurological function of cocaine. Recent studies have shown that HDAC11 is also critically involved in the pathogenesis of some metabolic diseases, including obesity, diabetes and complications of diabetes. In this review, we summarize the recent progress on the role and mechanism of HDAC11 in the regulation of metabolic disorders, with the focus on its regulation on adipogenesis, lipid metabolism, metabolic inflammation, glucose tolerance, immune responses and energy consumption. We also discuss the property and selectivity of HDAC11 inhibitors and their applications in a variety of in vitro and in vivo models of metabolic disorders. Given that pharmacological and genetic inhibition of HDAC11 exerts a beneficial effect on various metabolic disorders, HDAC11 may be a potential therapeutic target to treat chronic metabolic diseases.

Long noncoding RNA ST8SIA6-AS1 promotes cell proliferation and metastasis in triple-negative breast cancer by targeting miR-145-5p/CDCA3 to inactivate the p53/p21 signaling pathway

BACKGROUND

Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer, always exhibits a poor prognosis due to high risk of early recurrence and distant metastasis. Long noncoding RNAs (lncRNAs) have been reported as crucial regulators in breast cancer. However, the functions and action mechanisms of lncRNA ST8SIA6-AS1 in TNBC are largely unknown.

METHODS

Quantitative real-time PCR and western blot assays were used to measure the expression levels of different genes and proteins. Cell proliferation ability was monitored by CCK-8, colony forming and flow cytometry assays. Wound healing and transwell assays were performed to evaluate cell migration and invasion. The regulatory mechanisms of ST8SIA6-AS1 in TNBC were confirmed by dual luciferase reporter and RIP assays. A mouse xenograft model was established to investigate the role of ST8SIA6-AS1 in TNBC tumor growth.

RESULTS

ST8SIA6-AS1 displayed a higher expression in TNBC cells. Silencing ST8SIA6-AS1 impaired cell proliferation, cell cycle progression, migration, and invasion in vitro, and slowed tumor growth in vivo. Mechanistically, ST8SIA6-AS1 could facilitate the expression of its target CDCA3 (cell division cycle associated protein 3) and inactivate the p53/p21 signaling by inhibiting miR-145-5p. Moreover, miR-145-5p exerted a tumor-suppressive activity by targeting CDCA3. The tumor-suppressive effects induced by ST8SIA6-AS1 knockdown were abated by the down-regulation of miR-145-5p or the up-regulation of CDCA3.

CONCLUSION

ST8SIA6-AS1 exerts an oncogenic role in TNBC by interacting with miR-145-5p to up-regulate CDCA3 expression and inactivate the p53/p21 signaling, highlighting ST8SIA6-AS1 as a promising molecular target to combat TNBC.

LncRNA ST8SIA6-AS1 facilitates hepatocellular carcinoma progression by governing miR-651-5p/TM4SF4 axis

The oncogenic role of ST8SIA6-AS1 in different cancers was reported, including hepatocellular carcinoma (HCC). However, the underlying mechanism has not been completely explored. Real time quantitative PCR analysis was conducted to assess the ST8SIA6-AS1, miR-651-5p and TM4SF4 expression in HCC tissues and cells. Cell counting kit-8 and wound-healing migration assays were adopted to evaluate the HCC cell proliferation and migration, respectively. The expression of apoptosis-related proteins (Bax and Bcl-2) in human colorectal cancer cells (HCC) was determined by western blotting. In addition to bioinformatics analysis, RNA immunoprecipitation studies and luciferase reporter assays were undertaken to investigate the direct target relationship among ST8SIA6-AS1 and miR-651-5p or TM4SF4. Highly expressed ST8SIA6-AS1 and TM4SF4 as well as poorly expressed miR-651-5p were detected in HCC tissues and cells. Clinically, miR-651-5p expression in HCC tissues is negatively correlated with ST8SIA6-AS1 or TM4SF4. Cell functional assays demonstrated that ST8SIA6-AS1 silencing resulted in weakened proliferative and migratory capacities in HCC cells in addition to increase Bax expression and reduced Bcl-2 expression. ST8SIA6-AS1 exhibited its oncogenic function by sponging tumor suppressor miR-651-5p, and the anti-oncogenic of miR-651-5p was offset by its TM4SF4. The manipulation of ST8SIA6-AS1/miR-651-5p/TM4SF4 axis-mediated oncogenicity in HCC might shed new light on HCC diagnosis and therapy.

A pan-cancer analysis identifies HDAC11 as an immunological and prognostic biomarker

Histone deacetylase 11 (HDAC11) is aberrantly expressed in many types of cancer, and such abnormalities are associated with tumor immunity and heterogeneous clinical outcomes. Here, we explore the prognostic value and immunological function of HDAC11 across 33 cancer types. We observe HDAC11 is aberrantly expressed in 25 cancer types and positively or negatively associated with prognosis in different cancers. HDAC11 played a protective prognostic role in KIRP, KIRC, LGG, PCPG, READ, and UVM, which was contrary to the conventional opinion that HDAC11 was an oncogenic gene. Moreover, HDAC11 is negatively associated with tumor immune components, most immune checkpoint genes, and key cytokine expression. HDAC11 is correlated with tumor mutational burden in 11 cancer types and with microsatellite instability in 9 cancer types, suggesting HDAC11 may affect a patient's response to immune checkpoint inhibitor (ICI) therapy. In addition, HDAC11 is negatively correlated with the drug sensitivity of oxaliplatin, carmustine, ifosfamide, imexon, lomustine, and BN-2629, indicating the potential synergy between HDAC11 inhibitors and these anti-tumor drugs. In vitro assays indicate that HDAC11 inhibitor SIS17 combined with oxaliplatin shows a synergistic cytotoxic role in K562 cells while SIS17 has an antagonistic effect on the cytotoxic role of oxaliplatin in 769P cells. HDAC11 is also associated with hallmark pathways, including epithelial mesenchymal transition, IL-6/JAK/STAT3, and allograft rejection pathways. Overall, we provide clues regarding the key role of HDAC11 in multiple cancers.

ST8SIA6-AS1 promotes the development of hepatocellular carcinoma cells through miR-338-3p/NONO Axis

BACKGROUND

Increasing studies have shown a vital fact that long non-coding RNAs (lncRNAs) play a considerable regulatory role in hepatocellular carcinoma (HCC) progression. However, whether ST8 alpha-N-acetyl-neuraminide alpha-2, 8-sialyltransferase 6 antisense RNA 1 (ST8SIA6-AS1) affects the development of HCC is unclear.

METHODS

The target genes in HCC cell lines were quantified via utilzing quantitative real-time polymerase chain reaction (RT-qPCR) analysis and western blot. Effects of ST8SIA6-AS1 on proliferative, apoptosis and migratory ability of HCC cells were proved by a series of function experiments. The cellular distribution of ST8SIA6-AS1 was examined through fluorescent in situ hybridization (FISH) assay and subcellular fractionation experiments. RNA pulldown assay was implemented to explore the target of ST8SIA6-AS1. RNA Binding Protein Immunoprecipitation (RIP) and luciferase reporter assays were performed to identify the specific relationships between miR-338-3p and ST8SIA6-AS1/ non-POU domain containing octamer binding (NONO).

RESULTS

The expression of ST8SIA6-AS1 was apparently elevated in HCC cell. Silenced ST8SIA6-AS1 reduced proliferative, migratory and invasive ability of HCC cells. Moreover, ST8SIA6-AS1 targeted miR-338-3p to modulate the expression of NONO in HCC cells.

CONCLUSIONS

ST8SIA6-AS1 enhances the progression of HCC via miR-338-3p/NONO axis in vitro.

LncRNA ST8SIA6-AS1 Promotes Cholangiocarcinoma Progression by Suppressing the miR-145-5p/MAL2 Axis

BACKGROUND

The tumor-promoting roles of ST8SIA6-AS1 and miR-145-5p have been found in several cancers, but their function in cholangiocarcinoma (CHOL) remains speculative. The purpose of this study was to examine the regulatory functions of the ST8SIA6-AS1/MAL2/miR-145-5p pathway in CHOL progression.

METHODS

RT-qPCR assay was used to detect ST8SIA6-AS1 expression in CHOL tissues and cell lines. Cell migration, apoptosis, invasion, and proliferation abilities were assessed by RIP, RNA pull-down, and luciferase assays. CCK-8, BrdU, transwell, and FITC assays to investigate the regulatory functions of ST8SIA6-AS1, miR-145-5p, and MAL2 function in CHOL cells.

RESULTS

Findings revealed the enrichment of ST8SIA6-AS1 in CHOL tissues and cell lines. It was also found that ST8SIA6-AS1 facilitated cell growth and migration, but it reduced the apoptosis level of the CHOL cells. The results of experiments showed that ST8SIA6-AS1 sponged miR-145-5p, thereby allowing MAL2 to exert its biological function on CHOL cells.

CONCLUSION

This research suggested that the ST8SIA6-AS1/miR-145-5p/MAL2 axis could enhance CHOL progression, which might be useful to improve the clinical outcomes of CHOL patients.

HDAC11: a multifaceted histone deacetylase with proficient fatty deacylase activity and its roles in physiological processes

The histone deacetylases (HDACs) family of enzymes possess deacylase activity for histone and nonhistone proteins; HDAC11 is the latest discovered HDAC and the only member of class IV. Besides its shared HDAC family catalytical activity, recent studies underline HDAC11 as a multifaceted enzyme with a very efficient long-chain fatty acid deacylase activity, which has open a whole new field of action for this protein. Here, we summarize the importance of HDAC11 in a vast array of cellular pathways, which has been recently highlighted by discoveries about its subcellular localization, biochemical features, and its regulation by microRNAs and long noncoding RNAs, as well as its new targets and interactors. Additionally, we discuss the recent work showing the consequences of HDAC11 dysregulation in brain, skeletal muscle, and adipose tissue, and during regeneration in response to kidney, skeletal muscle, and vascular injuries, underscoring HDAC11 as an emerging hub protein with physiological functions that are much more extensive than previously thought, and with important implications in human diseases.

Aberrant Sialylation in Cancer: Biomarker and Potential Target for Therapeutic Intervention?

Simple Summary

Sialylation is a post-translational modification that consists in the addition of sialic acid to growing glycan chains on glycoproteins and glycolipids. Aberrant sialylation is an established hallmark of several types of cancer, including breast, ovarian, pancreatic, prostate, colorectal and lung cancers, melanoma and hepatocellular carcinoma. Hypersialylation can be the effect of increased activity of sialyltransferases and results in an excess of negatively charged sialic acid on the surface of cancer cells. Sialic acid accumulation contributes to tumor progression by several paths, including stimulation of tumor invasion and migration, and enhancing immune evasion and tumor cell survival. In this review we explore the mechanisms by which sialyltransferases promote cancer progression. In addition, we provide insights into the possible use of sialyltransferases as biomarkers for cancer and summarize findings on the development of sialyltransferase inhibitors as potential anti-cancer treatments.

Abstract

Sialylation is an integral part of cellular function, governing many biological processes including cellular recognition, adhesion, molecular trafficking, signal transduction and endocytosis. Sialylation is controlled by the levels and the activities of sialyltransferases on glycoproteins and lipids. Altered gene expression of these enzymes in cancer yields to cancer-specific alterations of glycoprotein sialylation. Mounting evidence indicate that hypersialylation is closely associated with cancer progression and metastatic spread, and can be of prognostic significance in human cancer. Aberrant sialylation is not only a result of cancer, but also a driver of malignant phenotype, directly impacting key processes such as tumor cell dissociation and invasion, cell-cell and cell-matrix interactions, angiogenesis, resistance to apoptosis, and evasion of immune destruction. In this review we provide insights on the impact of sialylation in tumor progression, and outline the possible application of sialyltransferases as cancer biomarkers. We also summarize the most promising findings on the development of sialyltransferase inhibitors as potential anti-cancer treatments.

Long Non-coding RNA ST8SIA6-AS1 Promotes Lung Adenocarcinoma Progression Through Sponging miR-125a-3p

Emerging evidence suggests that long non-coding RNA (lncRNA) plays a critical role in human disease progression. Recently, a novel lncRNA ST8SIA6-AS1 was shown as an important driver in various cancer types. Nevertheless, its contribution to lung adenocarcinoma (LUAD) remains undocumented. Herein, we found that ST8SIA6-AS1 was frequently overexpressed in LUAD cell lines, tissues, and plasma. Depletion of ST8SIA6-AS1 significantly inhibited LUAD cell proliferation and invasion in vitro and tumor growth in vivo. In term of mechanism, ST8SIA6-AS1 was transcriptionally repressed by tumor suppressor p53, and ST8SIA6-AS1 was mainly located in the cytoplasm and could abundantly sponge miR-125a-3p to increase nicotinamide N-methyltransferase (NNMT) expression, thereby facilitating LUAD malignant progression. Clinically, high ST8SIA6-AS1 was positively correlated with larger tumor size, lymph node metastasis, and later TNM stage. Moreover, ST8SIA6-AS1 was identified as an excellent indicator for MM diagnosis and prognosis. Collectively, our data demonstrate that ST8SIA6-AS1 is a carcinogenic lncRNA in LUAD, and targeting the axis of ST8SIA6-AS1/miR-125a-3p/NNMT may be a promising treatment for LUAD patients.