Inhibition of sirtuin 1 deacetylase by miR-211-5p provides a mechanism for the induction of cell death in breast cancer cells

TIPE2 deficiency amplifies inflammation and immune dysregulation in MASH through modulating hepatic lipid metabolism and immune cell function

BACKGROUND

Metabolic Dysfunction-Associated Steatohepatitis (MASH) affects nearly 25% of the global population, yet there are no effective pharmacological treatments. Tumor necrosis factor α-induced protein 8-like 2 (TIPE2) is expressed in various immune cells and is crucial for regulating both innate and adaptive immune responses. However, its role in MASH development and the underlying mechanisms remain unclear.

METHOD

In this study, the role of TIPE2 in MASH was investigated using TIPE2 knockout (KO) mice and human hepatic LO2 cells. Immune cell infiltration, cytokine levels, and gene expression were analyzed. Techniques included flow cytometry for immune cell profiling, cytokine analysis, RNA sequencing, and quantitative PCR (qPCR) for validating gene expression changes.

RESULTS

TIPE2 was identified as a key regulator in MASH, influencing immune modulation and metabolic processes. TIPE2 KO mice exhibited increased infiltration and activation of natural killer (NK) cells, M1 macrophages, and myeloid-derived suppressor cells (MDSCs), along with elevated pro-inflammatory cytokines such as IFN-gamma, TNF-alpha, IL- 1 beta, and IL- 6. MDSCs from TIPE2 KO mice demonstrated enhanced PD-L1 expression, contributing to chronic liver inflammation through T cell suppression. RNA sequencing revealed that TIPE2 overexpression in human hepatic LO2 cells upregulated genes associated with amino acid biosynthesis, carbon metabolism, lipid regulation, glycolysis, and gluconeogenesis. These findings were supported by qPCR analyses of liver samples from mice, confirming TIPE2's role in maintaining lipid homeostasis and modulating immune responses.

CONCLUSION

The study highlights the pivotal role of TIPE2 in immune regulation and its influence on immune cell activation and inflammatory responses, which are critical in MASH progression. By exploring TIPE2-mediated immune regulation and its impact on the interplay between immune cell dynamics and liver metabolism, this research underscores TIPE2's central role in linking immune dysfunction to metabolic disturbances in MASH.

Exploring the potential of gemcitabine-metal-organic frameworks in combating pancreatic cancer under ketogenic conditions

BACKGROUND

Inadequate treatment responses, chemotherapy resistance, significant heterogeneity, and lengthy treatment durations create an urgent need for new pancreatic cancer therapies. This study aims to investigate the effectiveness of gemcitabine-loaded nanoparticles enclosed in an organo-metallic framework under ketogenic conditions in inhibiting the growth of MIA-PaCa-2 cells.

METHODS

Gemcitabine was encapsulated in Metal-organic frameworks (MOFs) and its morphology and size distribution were examined using transmission electron microscopy (TEM) and Dynamic light scattering (DLS) with further characterization including FTIR analysis. Various drug groups were established to evaluate their influences on cell cytotoxicity, apoptosis rate, cell cycle distribution, levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), and cell migration.

RESULTS

The gemcitabine-MOF was thoroughly analyzed to determine its size, morphology, and chemical composition, confirming its successful preparation. The treatment results showed an increase in the number of apoptotic cells following gemcitabine-MOF treatment, which was found to be associated with cell cycle arrest in the sub-G1 phase. Moreover, these treatments also resulted in reduced cell migration, decreased activity of antioxidant enzymes (SOD, GPx), and increased accumulation of MDA. Additionally, when exposed to ketogenic conditions (where beta-hydroxybutyrate is present in a glucose-limited medium), there was a further increase in cell cycle arrest, accompanied by a more pronounced decrease in SOD and GPx activity, as well as decreased migration.

CONCLUSION

The use of metal-organic framework to encapsulate gemcitabine yielded notable pro-apoptotic effects in MIA-PaCa-2 cells with which ketogenic conditions had a synergistic effect that can hold promise for improving therapeutic options.

Keratinocyte exosomal LOC285194 ameliorates psoriasis by inhibiting the differentiation of CD4+T cells to Th17 cells through regulating miR-211-5p/SIRT1 axis

Keratinocytes exosome participates in the pathogenesis of psoriasis and exosomes always carry long non-coding RNAs (lncRNAs) into target cells to function as an essential immune regulator in psoriasis-related diseases. LncRNA LOC285194 is closely associated with the occurrence of psoriasis. However, whether keratinocyte exosomal LOC285194 participates in the process of psoriasis remains vague. Exosomes were authenticated by transmission electron microscope and nanoparticle tracking analysis (NTA). Relative gene expression was determined by reverse transcription-polymerase chain reaction (RT-PCR). Flow cytometry was used to monitor the proportion of immune cells. Fluorescence in situ hybridization was employed to determine the colocalization of lncRNA and miRNA. Keratinocyte exosomal LOC285194 was reduced in psoriasis patients and had a negative association with Th17 cell infiltration in psoriasis patients. LOC285194-downregulation contributed to the differentiation of CD4+T cells to Th17 cells. Cytokine cocktail treatment reduced LOC285194 expression in keratinocytes and keratinocyte exosome, subsequently promoted the differentiation of CD4+T cells to Th17 cells and Th17 cells-related molecular levels including IL-17A, IL-22 and TNF-α, which were notably abrogated by LOC285194-upregulation in keratinocytes. As a sponge of LOC285194, miR-211-5p inhibition induced the increase of Th17 cell proportion in CD4+T cells, while exosomes treatment isolated from cytokine cocktail-exposed keratinocytes further enhanced Th17 cell proportion, which were abolished by LOC285194 overexpressed-exosome treatment. Furthermore, silent information regulator 1 (SIRT1) mediated the regulation role of miR-211-5p on Th17 cell production. Combined with the imiquimod-induced psoriasis animal model, exosomes isolated from LOC285194-overexpressing keratinocytes relieved psoriasis symptom through regulating miR-211-5p/SIRT1 axis. LOC285194 upregulation in keratinocytes promoted the keratinocyte exosomal LOC285194, that could be absorbed by CD4+T cells, leading to the inhibition of Th17 cell differentiation through targeting miR-211-5p/SIRT1 axis. This study provides a novel molecular mechanism of Th17 cell accumulation-mediated psoriasis.

Therapeutic potential of β-hydroxybutyrate in the management of pancreatic neoplasms: exploring novel diagnostic and treatment strategies

Pancreatic neoplasm, a highly aggressive and often fatal cancer, poses challenges due to late detection and nonspecific symptoms. Therefore, both early diagnosis and appropriate therapeutic approaches are necessary to augment the condition of these patients. Cancer cells undergo metabolic deregulation, which enables their proliferation, survival, and invasion. As a result, it is crucial to focus on the metabolic pathways in prevalent cancers and explore treatment strategies that target these pathways to control tumor growth effectively. This is particularly relevant in cancers like pancreatic cancer, which undergo numerous metabolic alterations. The ketogenic regimen, characterized by low carbohydrate and protein contents and high-fat sources, does not involve caloric restriction. This allows for the induction of ketogenesis and an increase in ketone bodies, while insulin and glucose levels remain low even after meals. This unique metabolic state may influence the tumor microenvironment. Given the lack of unanimous agreement on the precise role and mechanism of the ketogenic diet, this review aims to clarify the diagnostic value and accuracy of ketone bodies in various types of pancreatic tumors and explore the potential anti-cancer effects of the ketogenic diet when used alone or in conjunction with chemotherapy, also to determine the potential of the ketogenic diet to be used as adjuvant therapy. The outcomes of this study are instrumental in enhancing our understanding of the benefits and drawbacks associated with employing this diet for the management and diagnosis of pancreatic cancer.

The dual role of sirtuins in cancer: biological functions and implications

Sirtuins are pivotal in orchestrating numerous cellular pathways, critically influencing cell metabolism, DNA repair, aging processes, and oxidative stress. In recent years, the involvement of sirtuins in tumor biology has garnered substantial attention, with a growing body of evidence underscoring their regulatory roles in various aberrant cellular processes within tumor environments. This article delves into the sirtuin family and its biological functions, shedding light on their dual roles-either as promoters or inhibitors-in various cancers including oral, breast, hepatocellular, lung, and gastric cancers. It further explores potential anti-tumor agents targeting sirtuins, unraveling the complex interplay between sirtuins, miRNAs, and chemotherapeutic drugs. The dual roles of sirtuins in cancer biology reflect the complexity of targeting these enzymes but also highlight the immense therapeutic potential. These advancements hold significant promise for enhancing clinical outcomes, marking a pivotal step forward in the ongoing battle against cancer.

Beta hydroxybutyrate induces lung cancer cell death, mitochondrial impairment and oxidative stress in a long term glucose-restricted condition

BACKGROUND

Metabolic plasticity gives cancer cells the ability to shift between signaling pathways to facilitate their growth and survival. This study investigates the role of glucose deprivation in the presence and absence of beta-hydroxybutyrate (BHB) in growth, death, oxidative stress and the stemness features of lung cancer cells.

METHODS AND RESULTS

A549 cells were exposed to various glucose conditions, both with and without beta-hydroxybutyrate (BHB), to evaluate their effects on apoptosis, mitochondrial membrane potential, reactive oxygen species (ROS) levels using flow cytometry, and the expression of CD133, CD44, SOX-9, and β-Catenin through Quantitative PCR. The activity of superoxide dismutase, glutathione peroxidase, and malondialdehyde was assessed using colorimetric assays. Treatment with therapeutic doses of BHB triggered apoptosis in A549 cells, particularly in cells adapted to glucose deprivation. The elevated ROS levels, combined with reduced levels of SOD and GPx, indicate that oxidative stress contributes to the cell arrest induced by BHB. Notably, BHB treatment under glucose-restricted conditions notably decreased CD133 expression, suggesting a potential inhibition of cell survival through the downregulation of CD133 levels. Additionally, the simultaneous decrease in mitochondrial membrane potential and increase in ROS levels indicate the potential for creating oxidative stress conditions to impede tumor cell growth in such environmental settings.

CONCLUSION

The induced cell death, oxidative stress and mitochondria impairment beside attenuated levels of cancer stem cell markers following BHB administration emphasize on the distinctive role of metabolic plasticity of cancer cells and propose possible therapeutic approaches to control cancer cell growth through metabolic fuels.

New insights of miRNA molecular mechanisms in breast cancer brain metastasis and therapeutic targets

Brain metastases in breast cancer (BC) patients are often associated with a poor prognosis. Recent studies have uncovered the critical roles of miRNAs in the initiation and progression of BC brain metastasis, highlighting the disease's underlying molecular pathways. miRNA-181c, miRNA-10b, and miRNA-21, for example, are all overexpressed in BC patients. It has been shown that these three miRNAs help tumors grow and metastasize by targeting genes that control how cells work. On the other hand, miRNA-26b5p, miRNA-7, and miRNA-1013p are all downregulated in BC brain metastasis patients. They act as tumor suppressors by controlling the expression of genes related to cell adhesion, angiogenesis, and invasion. Therapeutic miRNA targeting has considerable promise in treating BC brain metastases. Several strategies have been proposed to modulate miRNA expression, including miRNA-Mimics, antagomirs, and small molecule inhibitors of miRNA biogenesis. This review discusses the aberrant expression of miRNAs and metastatic pathways that lead to the spread of BC cells to the brain. It also explores miRNA therapeutic target molecular mechanisms and BC brain metastasis challenges with advanced strategies. The targeting of certain miRNAs opens a new door for the development of novel therapeutic approaches for this devastating disease.

HOTAIR in colorectal cancer: structure, function, and therapeutic potential

lncRNAs play a vital part in cancer development by regulating gene expression. Among these, the lncRNA HOTAIR has gained considerable attention due to its entanglement in multiple cellular processes, including chromatin remodeling and gene regulation. HOTAIR has a complex structure consisting of multiple domains that interact with various protein complexes and RNA molecules. In colorectal cancer (CRC), HOTAIR expression is upregulated, and its overexpression has been correlated with poor patient prognosis and resistance to chemotherapy. HOTAIR has been found to regulate gene expression and promote cancer growth by interacting with specific miRNAs. In addition, HOTAIR has been implicated in the development of treatment resistance in colorectal cancer. To develop effective treatments, it's important to understand how HOTAIR regulates gene expression. This article discusses HOTAIR's structure, functions, and mechanisms in CRC and its potential as a target for therapy. The author also suggests future research directions to better understand HOTAIR's role in CRC progression and drug resistance.

SIRT1 mediated gastric cancer progression under glucose deprivation through the FoxO1-Rab7-autophagy axis

Purpose

Silent mating type information regulator 2 homolog 1 (SIRT1) and autophagy have a two-way action (promoting cell death or survival) on the progression and treatment of gastric cancer (GC) under different conditions or environments. This study aimed to investigate the effects and underlying mechanism of SIRT1 on autophagy and the malignant biological behavior of GC cells under conditions of glucose deprivation (GD).

Materials and methods

Human immortalized gastric mucosal cell GES-1 and GC cell lines SGC-7901, BGC-823, MKN-45 and MKN-28 were utilized. A sugar-free or low-sugar (glucose concentration, 2.5 mmol/L) DMEM medium was used to simulate GD. Additionally, CCK8, colony formation, scratches, transwell, siRNA interference, mRFP-GFP-LC3 adenovirus infection, flow cytometry and western blot assays were performed to investigate the role of SIRT1 in autophagy and malignant biological behaviors (proliferation, migration, invasion, apoptosis and cell cycle) of GC under GD and the underlying mechanism.

Results

SGC-7901 cells had the longest tolerance time to GD culture conditions, which had the highest expression of SIRT1 protein and the level of basal autophagy. With the extension of GD time, the autophagy activity in SGC-7901 cells also increased. Under GD conditions, we found a close relationship between SIRT1, FoxO1 and Rab7 in SGC-7901 cells. SIRT1 regulated the activity of FoxO1 and upregulated the expression of Rab7 through deacetylation, which ultimately affected autophagy in GC cells. In addition, changing the expression of FoxO1 provided feedback on the expression of SIRT1 in the cell. Reducing SIRT1, FoxO1 or Rab7 expression significantly inhibited the autophagy levels of GC cells under GD conditions, decreased the tolerance of GC cells to GD, enhanced the inhibition of GD in GC cell proliferation, migration and invasion and increased apoptosis induced by GD.

Conclusion

The SIRT1-FoxO1-Rab7 pathway is crucial for the autophagy and malignant biological behaviors of GC cells under GD conditions, which could be a new target for the treatment of GC.

Regulation of Inflammasome by microRNAs in Triple-Negative Breast Cancer: New Opportunities for Therapy

During the past decade, researchers have investigated the molecular mechanisms of breast cancer initiation and progression, especially triple-negative breast cancer (TNBC), in order to identify specific biomarkers that could serve as feasible targets for innovative therapeutic strategies development. TNBC is characterized by a dynamic and aggressive nature, due to the absence of estrogen, progesterone and human epidermal growth factor 2 receptors. TNBC progression is associated with the dysregulation of nucleotide-binding oligomerization domain-like receptor and pyrin domain-containing protein 3 (NLRP3) inflammasome, followed by the release of pro-inflammatory cytokines and caspase-1 dependent cell death, termed pyroptosis. The heterogeneity of the breast tumor microenvironment triggers the interest of non-coding RNAs' involvement in NLRP3 inflammasome assembly, TNBC progression and metastasis. Non-coding RNAs are paramount regulators of carcinogenesis and inflammasome pathways, which could help in the development of efficient treatments. This review aims to highlight the contribution of non-coding RNAs that support inflammasome activation and TNBC progression, pointing up their potential for clinical applications as biomarkers for diagnosis and therapy.

MiR-211 plays a dual role in cancer development: From tumor suppressor to tumor enhancer

Cancer is a general term for more than 100 unique malignancies in different organs of the body. Each cancer type and subtype has its own unique genetic, epigenetic, and cellular factors accountable for malignant progression and metastasis. Small non-coding RNAs called miRNAs target mRNAs and play a vital part in the pathogenesis of human diseases, specifically cancer. Recent investigations provided knowledge of the deregulation of miR-211 in various cancer types and disclosed that miR-211 has an oncogenic or tumor-suppressive impact on tumourigenesis and cancer development. Moreover, recent discoveries which clarify the essential functions of miR-211 might provide proof for its prognosis, diagnostic and therapeutic impact on cancer. Thereby, this review will discuss recent findings regarding miR-211 expression level, target genes, and mechanisms in different cancers. In addition, the most recent results that propose miR-211 usefulness as a noninvasive biomarker and therapeutic factor for the diagnosis and treatment of cancer will be explained.

The sirtuin family in health and disease

Sirtuins (SIRTs) are nicotine adenine dinucleotide(+)-dependent histone deacetylases regulating critical signaling pathways in prokaryotes and eukaryotes, and are involved in numerous biological processes. Currently, seven mammalian homologs of yeast Sir2 named SIRT1 to SIRT7 have been identified. Increasing evidence has suggested the vital roles of seven members of the SIRT family in health and disease conditions. Notably, this protein family plays a variety of important roles in cellular biology such as inflammation, metabolism, oxidative stress, and apoptosis, etc., thus, it is considered a potential therapeutic target for different kinds of pathologies including cancer, cardiovascular disease, respiratory disease, and other conditions. Moreover, identification of SIRT modulators and exploring the functions of these different modulators have prompted increased efforts to discover new small molecules, which can modify SIRT activity. Furthermore, several randomized controlled trials have indicated that different interventions might affect the expression of SIRT protein in human samples, and supplementation of SIRT modulators might have diverse impact on physiological function in different participants. In this review, we introduce the history and structure of the SIRT protein family, discuss the molecular mechanisms and biological functions of seven members of the SIRT protein family, elaborate on the regulatory roles of SIRTs in human disease, summarize SIRT inhibitors and activators, and review related clinical studies.

The Mechanistic Roles of Sirtuins in Breast and Prostate Cancer

Simple Summary

There are diverse reports of the dual role of sirtuin genes and proteins in breast and prostate cancers. This review discusses the current information on the tumor promotion or suppression roles of SIRT1–7 in breast and prostate cancers. Precisely, we highlight that sirtuins regulate various proteins implicated in proliferation, apoptosis, autophagy, chemoresistance, invasion, migration, and metastasis of both breast and prostate cancer. We also provide evidence of the direct regulation of sirtuins by miRNAs, highlighting the consequences of this regulation in breast and prostate cancer. Overall, this review reveals the potential value of sirtuins as biomarkers and/or targets for improved treatment of breast and prostate cancers.

Abstract

Mammalian sirtuins (SIRT1–7) are involved in a myriad of cellular processes, including apoptosis, proliferation, differentiation, epithelial-mesenchymal transition, aging, DNA repair, senescence, viability, survival, and stress response. In this review, we discuss the current information on the mechanistic roles of SIRT1–7 and their downstream effects (tumor promotion or suppression) in cancers of the breast and prostate. Specifically, we highlight the involvement of sirtuins in the regulation of various proteins implicated in proliferation, apoptosis, autophagy, chemoresistance, invasion, migration, and metastasis of breast and prostate cancer. Additionally, we highlight the available information regarding SIRT1–7 regulation by miRNAs, laying much emphasis on the consequences in the progression of breast and prostate cancer.

Matrine promotes mitochondrial biosynthesis and reduces oxidative stress in experimental optic neuritis

Optic neuritis (ON), characterized by inflammation of the optic nerve and apoptosis of retinal ganglion cells (RGCs), is one of the leading causes of blindness in patients. Given that RGC, as an energy-intensive cell, is vulnerable to mitochondrial dysfunction, improving mitochondrial function and reducing oxidative stress could protect these cells. Matrine (MAT), an alkaloid derived from Sophoraflavescens, has been shown to regulate immunity and protect neurons in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis and ON. However, the protective mechanism of MAT on RGCs is largely unknown. In this study, we show that MAT treatment significantly reduced the degree of inflammatory infiltration and demyelination of the optic nerve and increased the survival rate of RGCs. The expression of Sirtuin 1 (SIRT1), a member of an evolutionarily conserved gene family (sirtuins), was upregulated, as well as its downstream molecules Nrf2 and PGC-1α. The percentage of TOMM20-positive cells was also increased remarkably in RGCs after MAT treatment. Thus, our results indicate that MAT protects RGCs from apoptosis, at least in part, by activating SIRT1 to regulate PGC-1α and Nrf2, which, together, promote mitochondrial biosynthesis and reduce the oxidative stress of RGCs.

A Proposed TUSC7/miR-211/Nurr1 ceRNET Might Potentially be Disturbed by a cer-SNP rs2615499 in Breast Cancer

Evidence and in silico analyses showed that TUSC7, miR-211, and Nurr1 may be involved in BC pathogenesis by ceRNET signaling axis. This study aimed to investigate the potential role of TUSC7/miR-211/Nurr1 ceRNET and rs2615499 variant as a novel cer-SNP in BC subjects. The expression assays were conducted by qPCR on tumor tissues (n = 50), tumor-adjacent normal tissues (TANTs) (n = 50), and clinically healthy control tissues (n = 50). The expression of TUSC7 and Nurr1 significantly decreased, but the level of miR-211 significantly increased in tumor tissues compared to TANTs and healthy normal tissues. Altered expression of TUSC7 and miR-211 was associated with poor prognosis of patients. The Nurr1 exhibited a double-edged sword-like activity in BC. In addition, TUSC7, Nurr1, and miR-211 expressions were significantly related to a novel BC-associated rs2615499 (A > C) located in the miR-211 binding site on Nurr1 3'-UTR. In the second part of the study, a case-control study was performed on BC patients (n = 100) and matched healthy controls (n = 100). The genomic DNA was isolated and genotyping was performed using Tetra-Primer ARMS PCR. The CC and AC genotypes were associated with higher expression levels of Nurr1 and worse outcomes of the disease. Our findings revealed that TUSC7 functions as a tumor suppressor in BC potentially via miR-211/Nurr1, which might be disturbed by the cer-SNP rs2615499. However, functional studies are needed to validate these results.

Dual role of microRNA-1297 in the suppression and progression of human malignancies

MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded and tiny RNAs that modulate several biological functions, more importantly, the pathophysiology of numerous human cancers. They are bound with target mRNAs and thereby regulate gene expression at post-transcriptional levels. MiRNAs can either trigger cancer progression as an oncogene or alleviate it as a tumor suppressor. Abnormal expression of microRNA-1297 (miR-1297) has been noticed in several human cancers suggesting a distinct role for the miRNA in tumorigenesis. More specifically, it is both up-regulated and down-regulated in various cancers suggesting that it can act as both tumor suppressor and oncogene. This review systematically highlights the different roles of miR-1297 in the pathophysiology of human cancers, explains the mechanisms underlying miR-1297-mediated tumorigenesis, and discusses its potential prognostic, diagnostic, and therapeutic importance.

Knockdown of long non-coding RNA NEAT1 relieves the inflammatory response of spinal cord injury through targeting miR-211-5p/MAPK1 axis

Spinal cord injury (SCI) is a refractory disease often accompanied by inflammation. Long non-coding RNA NEAT1 (lncRNA NEAT1) was reported to be involved in the expression of the inflammasomes, while the regulatory effect of NEAT1 on SCI was poorly investigated. Herein, we carried out further studies on the pathogenesis of SCI. PC-12 cells were incubated with lipopolysaccharide (LPS) to induce inflammation. Western blotting assay was used to measure the protein expression levels. RNA expression levels were analyzed using RT-qPCR. Cell counting kit 8 and flow cytometry assays were used to separately determine the cell viability and apoptosis rate. The targeted relationships were verified by luciferase reporter and RNA pull-down assays. It was found that LPS induced inflammation in the PC-12 cells, leading to significantly higher cell apoptosis rate and lower viability, and the expression level of NEAT1 was elevated by LPS. However, knockdown of NEAT1 partially reversed the effects of LPS. Subsequently, the potential interaction between NEAT1 and miR-211-5p was validated and miR-211-5p inhibitor was further confirmed to antagonize the effects of NEAT knockdown. The downstream target gene of miR-211-5p was predicted and verified to be MAPK1. In addition, overexpression of MAPK1 was proved to antagonize the effects of NEAT1 knockdown. Taken together, the knockdown of NEAT1 remarkably alleviated the inflammation of SCI via miR-211-5p/MAPK1 axis.

Trending topics of SIRT1 in tumorigenicity

BACKGROUND

Carcinogenesis is governed by a series of genetic alterations and epigenetic changes that lead to aberrant patterns in neoplastic cells. Sirtuin-1(SIRT1), an NAD⁺-dependent protein deacetylase, is capable of deacetylating histones and non-histone substrates that regulate various physiological activities during tumorigenesis. Recent studies have identified the role of SIRT1 in different stages of cancer, including genome instability, tumor initiation, proliferation, metabolism, and therapeutic response. However, the action of SIRT1 has been reported to be both oncogenic and tumor suppressive during carcinogenesis. Consequently, the biological functions of SIRT1 in cancer remain controversial.

SCOPE OF REVIEW

We highlight the most recent findings on SIRT1 in different stages of tumorigenesis, and update the current status of SIRT1 small molecule modulators in clinical application of cancer treatment.

MAJOR CONCLUSION

By targeting both tumor suppressors and oncogenic proteins, SIRT1 has a bifunctional role at different stages of tumorigenesis. The impact of SIRT1 on tumorigenesis is also distinct at different stages and is dependent on its dosages. SIRT1 suppresses tumor initiation through its functions in promoting DNA repair, increasing genome stability, and inhibiting inflammation at the pre-cancer stage. However, SIRT1 enhances tumor proliferation, survival, and drug resistance through its roles in anti-apoptosis, pro-tumor metabolism, and anti-inflammation (inhibition of anti-tumor immunity) at the stages of tumor progression, metastasis, and relapse. Consequently, both SIRT1 inhibitors and activators have been explored for cancer treatment.

GENERAL SIGNIFICANCE

Better understanding the dose- and stage-dependent roles of SIRT1 in each cancer type can provide new avenues of exploration for therapy development.

Circular RNA circ_0001588 sponges miR-211-5p to facilitate the progression of glioblastoma via up-regulating YY1 expression

BACKGROUND

As the most common and detrimental brain tumor with high invasiveness and poor prognosis, glioblastoma (GBM) has severely threatened people's health globally. Therefore, it is of great importance and necessary to identify the molecular mechanisms involved in tumorigenesis and development, thus contributing to potential therapeutic targets and strategies.

METHODS

The level of circ_0001588 was detected in 68 pairs of GBM tissues and adjacent normal tissues and human glioma cell lines via a real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Then, the effect of circ_0001588 on the proliferation, migration and invasion of glioma cells was evaluated. In addition, potential downstream targets of circ_0001588 were forecasted by circBANK and Starbase. Their interaction was confirmed by introducing luciferase reporter assays. Moreover, sh-circ_0001588 transfected U251 cells were used to form tumors in vivo. Finally, the functional mechanism of circ_0001588 was identified by qRT-PCR, western blotting, xenograft and immunohistochemistry (IHC) assays.

RESULTS

The expression of circ_0001588 is markedly up-regulated in GBM tissues and human gliomas cells. Additionally, increased expression of circ_0001588 is positively relevant with poor survival in GBM patients. The down-regulation of circ_0001588 distinctly inhibits the proliferation, migration and invasion of GBM in vitro, as well as tumor growth in vivo. Moreover, knockdown of circ_0001588 reduces the tumor volume and weight, enhances the relative IHC staining index of E-cadherin and decreases the relative IHC staining index of Ki-67, Yin Yang 1 (YY1) and vinmentin in vivo. Mechanistically, circ_0001588 locates in the cytoplasm, which is directly bound with miR-211-5p. Furthermore, circ_0001588 can positively regulate YY1 via sponging miR-211-5p. Moreover, circ_0001588 accelerates the proliferation, migration and invasion of GBM by modulating miR-211-5p/YY1 signaling.

CONCLUSIONS

These results illustrate a new circ_0001588/miR-211-5p/YY1 regulatory signaling axis in GBM.

Circulating miRNAs as early indicators of diet and physical activity response in women with metastatic breast cancer

Treatments for metastatic breast cancer (MBC) improve survival but often impose prolonged symptom burden. We performed molecular characterization of 84 miRNAs in the circulating serum of women with MBC to explore possible early indicators of intervention response. Expression levels of miR-10a-5p and miR-211-5p were downregulated in nonresponders, but upregulated in responders (miR-10a-5p: 0.40-fold and eightfold; miR 211-5p: 0.47-fold and fourfold). miR-205-5p expression was upregulated in both nonresponders and responders, but to a greater extent in responders (1.8-fold and sixfold). Additionally, levels of miR-10a-5p were negatively correlated with expression levels of IL-6 (r = -0.412). Exploration of these pathways may reveal mechanisms of action in lifestyle interventions aimed at improving quality of life and impacting disease progression for women with MBC.

As treatment for women with metastatic breast cancer improves survival rates, interventions are needed that relieve symptom burden. We examined the serum of women with metastatic breast cancer who participated in a lifestyle intervention that improved diet and increased physical activity. Three miRNAs were discovered that may serve as early indicators of the ability of lifestyle interventions to improve quality of life and impact disease progression.

Three miRNAs may predict how women with metastatic breast cancer respond to lifestyle interventions.

LncRNA KCNQ1OT1 Promotes Proliferation, Invasion and Metastasis of Prostate Cancer by Regulating miR-211-5p/CHI3L1 Pathway

Background

Bone metastasis after failure of castration therapy is the main reason of death in patients with prostate cancer (PCa). Therefore, full awareness of the metastasis mechanism of PCa and discovery of new therapeutic targets are necessary. Studies showed that lncRNA was involved in the development of cancer. However, its potential role and molecular mechanism in PCa metastasis are still unclear. YKL-40 is an 18 glycosyl hydrolase family protein encoded by CHI3L1, which is involved in the invasion and metastasis of various tumors. A previous study of the authors found that YKL-40 was related to the invasion and metastasis of PCa cells. However, the cause of its abnormal expression in PCa remains unclear. The present study explored the role of lncRNA KCNQ1OT1/miR-211-5p/CHI3L1 regulatory axis in the proliferation, invasion, and metastasis of PCa.

Methods

RT-PCR and Western blot were used to measure the expression profiles of KCNQ1OT1 and YKL. CCK-8 and Transwell assays were used to examine their effects on cell proliferation and migration. Double luciferase reporter assay was used to verify the interactions between miR-211-5p and CHI3L1 3′-UTR.

Results

KCNQ1OT1 expression was upregulated in PCa tissues and cells. Downregulating this expression inhibited PCa cell invasion, proliferation, and metastasis. KCNQ1OT1 bound miR-211-5p competitively, and miR-211-5p targeted CHI3L1 3′-UTR. miR-211-5p expression was downregulated, whereas CHI3L1 (YKL-40) expression was upregulated. miR-211-5p levels were negatively correlated with KCNQ1OT1 expression and CHI3L1 mRNA. The decrease in YKL-40 expression in PCa cells induced by the downregulation of KCNQ1OT1 expression could be offset by miR-211-5p inhibitor transfection.

Conclusion

This study showed that lncRNA KCNQ1OT1, as a ceRNA, upregulated CHI3L1 and promoted PCa progression through competitive binding to miR-211-5p.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

MicroRNA-383-5p acts as a potential prognostic biomarker and an inhibitor of tumor cell proliferation, migration, and invasion in breast cancer

BACKGROUND

MicroRNAs (miRNAs) have been reported to serve as potential biomarkers in various cancer and play important roles in tumor progression.

OBJECTIVE

The aim of this study was to investigate the prognostic significance and functional role of miR-383-5p in breast cancer.

METHODS

The expression levels of miR-383-5p in breast cancer tissues and cell lines were measured using quantitative real-time PCR analysis. Kaplan-Meier curve and Cox regression analysis were used to explore the prognostic significance of miR-383-5p in breast cancer. The CCK-8 assay was used to assess cell proliferation ability. Transwell assays were used to assess cell migration and invasion abilities of breast cancer cells.

RESULTS

The expression of miR-383-5p was significantly downregulated in breast cancer tissues and cell lines, compared with that in normal tissues and normal epithelial MCF-10A cells, respectively. The expression of miR-383-5p was associated with differentiation, lymph node metastasis, and TNM stage. Patients with low miR-383-5p expression had shorter overall survival than those with high miR-383-5p expression. Overexpression of miR-383-5p significantly inhibited cell proliferation, migration, and invasion, while downregulation of miR-383-5p promoted cell proliferation, migration, and invasion in vitro. LDHA was a direct target of miR-383-5p.

CONCLUSIONS

Taken together, miR-383-5p was downregulated in breast cancer tissues and cell lines, and overexpression of miR-383-5p inhibited cell proliferation, migration, and invasion in breast cancer cells by targeting LDHA. Based on our findings, miR-383-5p may be a prognostic biomarker and therapeutic target for breast cancer.

Berberine Inhibits the Expression of SCT through miR-214-3p Stimulation in Breast Cancer Cells

In this study, we aimed to evaluate the suppressive abilities of berberine (BBR) on MCF-7 and MDA-MB-231 cells and confirm its underlying mechanisms on miR-214-3p. We first built a panel of 18 miRNAs and 9 lncRNAs that were reported to participate in the mechanism of breast cancer. The RT-qPCR results suggested that BBR illustrated a dosage-dependent pattern in the stimulation to miR-214-3p in both MCF-7 and MDA-MB-231 cells. Then, we performed gain-and-lose function tests to validate the role of miR-214-3p contributing to the anticancer effects of BBR. Both BBR and miR-214-3p mimic reduced the cell viability, repressed migration and invasion capacities, increased rates of total apoptotic cells and ratio of Bax/Bcl-2, and increased the percentage of G2/M cells of MCF-7 and MDA-MB-231 cells by colony formation and CKK8 assay, scratch wound healing and gelatin-based 3D conformation assay, transwell invasion assay, and cell cycle analysis, respectively. However, miR-214-3p inhibitor counteracted all these effects of BBR. Based on the bioinformatics analysis and dual-luciferase reporter test, we identified binding sites between SCT and miR-214-3p. We further confirmed that BBR massively and dose-dependently reduced the mRNA expression and protein levels of SCT in both MCF-7 and MDA-231 cells. We testified that both miR-214-3p mimic and BBR could decrease the mRNA expression and protein levels of SCT, while miR-214-3p inhibitor weakened these reductions. In conclusion, BBR suppressed MCF-7 and MDA-MB-231 breast cancer cells by upregulating miR-214-3p and increasing its inhibition to SCT.

Identification of Functional Genes in Pterygium Based on Bioinformatics Analysis

Purpose

The competing endogenous RNA (ceRNA) network regulatory has been investigated in the occurrence and development of many diseases. This research aimed at identifying the key RNAs of ceRNA network in pterygium and exploring the underlying molecular mechanism.

Methods

Differentially expressed long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs were obtained from the Gene Expression Omnibus (GEO) database and analyzed with the R programming language. LncRNA and miRNA expressions were extracted and pooled by the GEO database and compared with those in published literature. The lncRNA-miRNA-mRNA network was constructed of selected lncRNAs, miRNAs, and mRNAs. Metascape was used to perform Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses on mRNAs of the ceRNA network and to perform Protein-Protein Interaction (PPI) Network analysis on the String website to find candidate hub genes. The Comparative Toxicogenomic Database (CTD) was used to find hub genes closely related to pterygium. The differential expressions of hub genes were verified using the reverse transcription-real-time fluorescent quantitative PCR (RT-qPCR).

Result

There were 8 lncRNAs, 12 miRNAs, and 94 mRNAs filtered to construct the primary ceRNA network. A key lncRNA LIN00472 ranking the top 1 node degree was selected to reconstruct the LIN00472 network. The GO and KEGG pathway enrichment showed the mRNAs in ceRNA networks mainly involved in homophilic cell adhesion via plasma membrane adhesion molecules, developmental growth, regulation of neuron projection development, cell maturation, synapse assembly, central nervous system neuron differentiation, and PID FOXM1 PATHWAY. According to the Protein-Protein Interaction Network (PPI) analysis on mRNAs in LINC00472 network, 10 candidate hub genes were identified according to node degree ranking. Using the CTD database, we identified 8 hub genes closely related to pterygium; RT-qPCR verified 6 of them were highly expressed in pterygium.

Conclusion

Our research found LINC00472 might regulate 8 hub miRNAs (miR-29b-3p, miR-183-5p, miR-138-5p, miR-211-5p, miR-221-3p, miR-218-5p, miR-642a-5p, miR-5000-3p) and 6 hub genes (CDH2, MYC, CCNB1, RELN, ERBB4, RB1) in the ceRNA network through mainly PID FOXM1 PATHWAY and play an important role in the development of pterygium.

MicroRNA-154: A Novel Candidate for Diagnosis and Therapy of Human Cancers

MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded, tiny RNAs with 21-23 nucleotides that regulate several biological functions through binding to target mRNAs and modulating gene expression at post-transcriptional levels. Recent studies have described crucial roles for miRNAs in pathophysiology of numerous human cancers. They can act as an oncogene and promote cancer or as a tumor suppressor and alleviate the disease. Recently discovered microRNA-154 (miR-154) has been proposed to be involved in multiple physiological and pathological processes including cancer. With this aspect, aberrant expression of miR-154 has been demonstrated in variety of human malignancies, suggesting an important role for miR-154 in tumorigenesis. To be specific, it is considered as a tumor suppressor miRNA and exerts its beneficial effects by targeting several genes. This review systematically summarizes the recent advances done on the role of miR-154 in different cancers and discusses its potential prognostic, diagnostic and therapeutic values.

Impact of Sirtuin Enzymes on the Altered Metabolic Phenotype of Malignantly Transformed Cells

Sirtuins compose a unique collection of histone deacetylase enzymes that have a wide variety of enzymatic activities and regulate diverse cell functions such as cellular metabolism, longevity and energy homeostasis, mitochondrial function, and biogenesis. Impaired sirtuin functions or alterations of their expression levels may result in several pathological conditions and contribute to the altered metabolic phenotype of malignantly transformed cells in a significant manner. In the twenty-first century, principles of personalized anticancer treatment need to involve not only the evaluation of changes of the genetic material, but also the mapping of epigenetic and metabolic alterations, to both of which the contribution of sirtuin enzymes is fundamental. Since sirtuins are central players in the maintenance of cellular energy and metabolic homeostasis, they are key elements in the development of metabolic transformation of cancer cells referred to as the Warburg effect. Although its most well-known features are enhanced glycolysis and excessive lactate production, Warburg effect has several aspects involving both carbohydrate, lipid, and amino acid metabolism, among which different tumor types have different preferences. Therefore, energy supply of cancer cells can be impaired by a growing number of antimetabolite agents, for which appropriate vectors are strongly needed. However, data are controversial about their tumor suppressor or oncogenic properties, the biological effects of sirtuin enzymes strongly depend on the tissue microenvironment (TME) in which they are expressed. Immune cells are regarded as key players of TME. Sirtuins regulate the survival, activation, metabolism, and mitochondrial function of these cells, therefore, they are not only single elements, but key regulators of the network that determines anticancer immunity. Altered metabolism of tumor cells induces changes in the gene expression pattern of cells in TME, due to altered concentrations of metabolite cofactors of epigenetic modifiers including sirtuins. In summary, epigenetic and metabolic alterations in malignant diseases are influenced by sirtuins in a significant manner, and should be treated in a personalized approach. Since they often develop in early stages of cancer, broad examination of these alterations is required at time of the diagnosis in order to provide a personalized combination of distinct therapeutic agents.

Retracted Article: MicroRNA-1271 modulates hepatitis B virus replication, cell proliferation and apoptosis in hepatitis B virus-related hepatocellular carcinoma by targeting SIRT1

Chronic hepatitis B virus (HBV) infection is a leading cause of hepatocellular carcinoma (HCC). Certain studies have revealed that microRNAs play crucial roles in HBV-related HCC. The aim of this study was to investigate the effects of microRNA-1271 (miR-1271) on HBV replication, cell proliferation and apoptosis in HBV-related HCC. The expression of HBV DNA and miR-1271 was detected by quantitative real time-polymerase chain reaction (qRT-PCR). The mRNA and protein levels of SIRT1 were detected by qRT-PCR and western blot analysis, respectively. HBV replication was assessed by the expression of HBV DNA and the levels of HBsAg and HBeAg. Cell proliferation was assessed by cell counting kit-8 (CCK-8) and 5-bromo-2-deoxyuidine (BrdU) assay, and apoptosis was evaluated by flow cytometry assay, enzyme-linked immunosorbent assay (ELISA) and the activity of caspase-3. The relationship between miR-1271 and SIRT1 was predicated by online software and confirmed by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) and pull-down assay. We first found that the expression of miR-1271 was downregulated and SIRT1 was upregulated in both HBV-related HCC tissues and cells. Overexpression of miR-1271 inhibited HBV replication and cell proliferation whilst promoting apoptosis in HBV-related HCC cells. Subsequently, SIRT1 was identified as a target of miR-1271. Moreover, overexpression of SIRT1 reversed the effects of miR-1271 overexpression on HBV replication, cell proliferation and apoptosis in HBV-related HCC cells. In conclusion, our study demonstrated that miR-1271 inhibited HBV replication and proliferation and promoted apoptosis of HBV-related HCC cells via targeting SIRT1, which might contribute to the diagnosis and therapy of HBV-related HCC.

MiR-1271 suppressed HBV-related HCC cells development by downregulating SIRT1.