Decreased expression of sestrin 2 predicts unfavorable outcome in colorectal cancer

Sestrins in Carcinogenesis-The Firefighters That Sometimes Stoke the Fire

Sestrins (SESN1-3) are a family of stress-responsive proteins that regulate cellular metabolism and redox balance, both of which are frequently disrupted in cancer. As direct targets of stress-responsive transcription factors, including tumour suppressor p53, Sestrins function as leucine-dependent inhibitors of mTORC1 and potent antioxidants. Their downregulation is widely observed across multiple cancers and is associated with increased tumour growth and poor prognosis. Despite their consistent tumour-suppressive effects through mTORC1 inhibition and promotion of p53-dependent apoptosis, Sestrins exhibit a limited role in tumour initiation, which appears to be context-dependent. Their antioxidant activity reduces oxidative damage, thereby protecting against genomic instability and other cancer-promoting events. However, in certain contexts, Sestrins may promote tumour survival and progression by stimulating pro-survival pathways, such as AKT signalling through mTORC2 activation. This review examines the molecular mechanisms underlying these dual functions, with a particular focus on mTOR signalling and oxidative stress. We also discuss Sestrin expression patterns and functional outcomes in various cancer types, including lung, liver, colon, skin, prostate, and follicular lymphomas, highlighting their potential as diagnostic markers and therapeutic targets.

Investigation of sestrin-2 levels and thiol-disulfide homeostasis in polyp tissue of patients with nasal polyps

Nasal polyposis (NP), a chronic inflammatory disease of the upper respiratory tract, has a poorly understood pathophysiology and no etiological factors explaining its pathogenesis, but inflammation remains an important factor. Sestrins (SESNS), which are conserved antioxidant proteins that accumulate in cells in response to various stresses, regulate the regulatory roles of SESN2 in the immune system and inflammatory responses. In the current study, we aimed to investigate the sestrin-2 pathway, oxidative stress and thiol-disulfide homeostasis in NP tissue of patients. The study included a total of 90 participants with the age 12-65 years. The patient group consisted of 45 patients diagnosed with NP and free from chronic disease. The control group comprised 45 patients who underwent nose surgery for anatomical pathology other than NP. The levels of native thiol, total thiol, disulfide, disulfide/native thiol and disulfide/total thiol were found to be significantly higher in the patient group, while native thiol/total thiol levels were lower when compared to the control group. Besides, the levels of total oxidant status (TOS) and oxidative stress index (OSI) were significantly higher while total antioxidant status (TAS) levels were significantly lower compared to the control group. Also, extracellular signal-regulated kinase 1/2 (ERK1/2) levels were found to be higher and SESN2 lower than those in control group. The findings show that decreased SESN2, TAS levels and increased ERK1/2, TOS and OSI levels and impaired thiol-disulfide homeostasis in polyp tissues of patients with NP cause oxidative stress.

Integration analysis of microRNAs as potential biomarkers in early-stage lung adenocarcinoma: the diagnostic and therapeutic significance of miR-183-3p

Introduction

Lung adenocarcinoma (LUAD) poses a significant therapeutic challenge, primarily due to delayed diagnosis and the limited efficacy of existing treatments.

Methods

To understand the pathogenesis and identify diagnostic biomarkers for LUAD in the early stage, we investigated differential miRNA expression in 33 stage I LUAD patients between tumor and matched paracancerous tissues by Illumina Sequencing. Target genes of differentially expressed miRNAs were predicted using TargetScan and miRDB databases and further analyzed by GO and KEGG pathway enrichment analysis. The miRNAs expression results were verified using qRT-PCR. Additionally, we evaluated the clinical significance of miRNAs by the TCGA database. miR-183-3p was chosen for subsequent biological functional studies by cell proliferation assays, cell migration and cell invasion assays, cell apoptosis and cell cycle assays in LUAD cells. The clinical relevance target genes of miR-183-3p were predicted by TargetScan databases and bioinformatics assays. Gene-specific experimental validation was performed using qRT-PCR, western blotting and luciferase reporter assays.

Results

We identified 36 differentially expressed miRNAs between LUAD tissues and matched paracancerous tissues. Target genes for these miRNAs revealed associations with processes and pathways such as RNA biosynthesis, intracellular signaling, protein transport, and the Ras, MAPK, and PI3K-AKT pathways. The qRT-PCR results were in alignment with the sequencing data for 19 out of these 21 miRNAs which not yet implicated in LUAD, 13 were up-regulated, 6 were down-regulated. The clinical relevance assays showed that 5 up-regulated miRNAs have diagnostic value for LUAD. miR-183-3p showed significant advantages in the result of sequencing, qRT-PCR, and clinical relevance assay. Biological functional assays showed that miR-183-3p emerged as a key regulator, promoting LUAD cell proliferation, decreasing apoptosis, and augmenting migration and invasion capabilities. The clinical relevance assays and experimental validation showed SESN1 as a clinical significance target of miR-183-3p.

Discussion

Our study lays the foundation for investigating miRNAs with diagnostic significance in early-stage LUAD, pointing out that inhibition of miR-183-3p may serve as a novel therapeutic in LUAD.

DNA methylation-driven gene FAM3D promotes colorectal cancer growth via the ATF4-SESN2-mTORC1 pathway

Globally, colorectal cancer (CRC) is the malignant tumor with the highest mortality rate after lung cancer. Abnormal DNA methylation drives dysregulated gene expression, thereby promoting CRC progression and leading to poor prognosis. We identified a 3-CpG methylation signature that is independently associated with CRC prognosis. The model consists of three methylation-driven genes: FAM3 Metabolism Regulating Signaling Molecule D (FAM3D), DAPP1, and PIGR. However, the prognostic significance, biological function, and related mechanisms of the individual methylation-driven gene FAM3D in CRC have not been studied. Here, we discovered that FAM3D expression was reduced in CRC tissues and cells, and that high methylation and low expression of FAM3D were independent prognostic risk factors for CRC. In addition, FAM3D promoted the growth and movement of CRC cells in vitro and the proliferation in nude mice, mainly by inhibiting ATF4 transcription and downregulating SESN2 expression, and ultimately activating mTORC1. Furthermore, FAM3D resulted in reduced sensitivity of CRC cells to oxaliplatin, cisplatin, and 5-fluorouracil. Our study showed that FAM3D activates the mTORC1 pathway through the ATF4-SESN2 axis and promotes the malignant progression of CRC, which contributes to predict CRC prognosis and guide individualized treatment.

Sestrin2 and Sestrin3 protect spermatogenesis against heat-induced meiotic defects†

Heat stress induces testicular oxidative stress, impairs spermatogenesis, and increases the risk of male infertility. Recent studies have highlighted the antioxidative properties of the Sestrins family in reducing cellular oxidative damage. However, the role of Sestrins (Sestrin1, 2, and 3) in the testicular response to heat stress remains unclear. Here, we found that Sestrin2 and 3 were highly expressed in the testis relative to Sestrin1. Then, the Sestrin2-/- and Sestrin3-/- mice were generated by CRISPR/Cas9 to investigate the role of them on spermatogenesis after heat stress. Our data showed that Sestrin2-/- and Sestrin3-/- mice testes exhibited more severe damage manifested by exacerbated loss of germ cells and higher levels of oxidative stress as compared to wild-type counterparts after heat stress. Notably, Sestrin2-/- and Sestrin3-/- mice underwent a remarkable increase in heat-induced spermatocyte apoptosis than that of controls. Furthermore, the transcriptome landscape of spermatocytes and chromosome spreading showed that loss of Sestrin2 and Sestrin3 exacerbated meiotic failure by compromising DNA double-strand breaks repair after heat stress. Taken together, our work demonstrated a critical protective function of Sestrin2 and Sestrin3 in mitigating the impairments of spermatogenesis against heat stress.

Role of sestrins in metabolic and aging-related diseases

Sestrins are a type of highly conserved stress-inducing protein that has antioxidant and mTORC1 inhibitory functions. Metabolic dysfunction and aging are the main risk factors for development of human diseases, such as diabetes, neurodegenerative diseases, and cancer. Sestrins have important roles in regulating glucose and lipid metabolism, anti-tumor functions, and aging by inhibiting the reactive oxygen species and mechanistic target of rapamycin complex 1 pathways. In this review, the structure and biological functions of sestrins are summarized, and how sestrins are activated and contribute to regulation of the downstream signal pathways of metabolic and aging-related diseases are discussed in detail with the goal of providing new ideas and therapeutic targets for the treatment of related diseases.

Association between the antioxidant properties of SESN proteins and anti-cancer therapies

Since the beginning of SESN protein development, they have attracted highly progressive attention due to their regulatory role in multiple signalling pathways. Through their antioxidant activity and autophagy regulation implication, they can function as powerful antioxidants to reduce oxidative stress in cells. SESN proteins received special attention in the field of regulation of reactive oxygen species level in the cell and its interplay with signalling pathways determining energy and nutrient homeostasis. Since perturbations in these pathways are implicated in cancer onset and development, SESNs might constitute potential novel therapeutic targets of broad interest. In this review, we discuss the impact of SESN proteins on anti-cancer therapy based on naturally occurring compounds and conventionally used drugs that influence oxidative stress and autophagy-induced cellular signalling pathways. The significant changes in reactive oxygen species level and nutrient status in cancer cells generate subsequent biological effect through the regulation of SESN-dependent pathways. Thus, SESN may serve as the key molecule for regulating anti-cancer drugs' induced cellular response.

Predictors of Survival Among the Oldest Old Following Acute Hospital Admission: Insights From Clinical and Biochemical Factors

Understanding the factors influencing survival in oldest old population is crucial for providing appropriate care and improving outcomes. This prospective observational study aimed to investigate the determinants of survival in acutely ill oldest old patients during acute hospitalization and 1-month follow-up. Various geriatric domains and biochemical markers were assessed. Among the 70 included patients with a median age of 87 (Inter quartile range: 85-90), the presence of diabetes, delirium, tachypnea, and high sirtuin-5 levels were associated with reduced in-hospital survival. Non-survivors had raised levels of Sirtuin 1 and Sirtuin 5, with an increase of 43% and 70%, respectively. At 1 month, delirium and diabetes were still associated with reduced survival. These findings suggest that type-2 diabetes, delirium, tachypnea, and high sirtuin-5 levels could serve as predictors of reduced survival in acutely ill, hospitalized oldest old patients.

SESN2 Knockdown Increases Betulinic Acid-Induced Radiosensitivity of Hypoxic Breast Cancer Cells

Betulinic acid (BA) is a natural compound well known for its anti-inflammatory, anti-viral, anti-bacterial, anti-malarial effects and anti-tumor properties. Its enhanced cytotoxicity in tumor cells and induction of cell death in various cancer entities qualifies BA as an interesting candidate for novel treatment concepts. Our analyses showed enhanced cytotoxicity and radiosensitization under hypoxic conditions in human breast cancer cells. So far, the underlying mechanisms are unknown. Therefore, we investigated the BA-treated human breast cancer cell lines MDA-MB-231 and MCF-7 under normoxic and hypoxic conditions based on microarray technology. Hypoxia and BA regulated a variety of genes in both breast cancer cell lines. KEGG pathway analysis identified an enrichment of the p53 pathway in MCF-7 cells (wtp53) under hypoxia. In MDA-MB-231 cells (mtp53) an additional BA incubation was required to activate the p53 signaling pathway. Fourteen down-regulated and up-regulated genes of the p53 pathway were selected for further validation via qRT-PCR in a panel of five breast cancer cell lines. The stress-induced gene Sestrin-2 (SESN2) was identified as one of the most strongly up-regulated genes after BA treatment. Knockdown of SESN2 enhanced BA-induced ROS production, DNA damage, radiosensitivity and reduced autophagy in breast cancer cells. Our results identified SESN2 as an important target to enhance the radiobiological and anti-tumor effects of BA on breast cancer cells.

Calycosin induces autophagy and apoptosis via Sestrin2/AMPK/mTOR in human papillary thyroid cancer cells

Calycosin, one of small molecules derived from astragalus, has anti-tumor effects in various tumors. However, the effects of calycosin on papillary thyroid cancer (PTC) remain unclear. This study aimed to explore the anti-tumor ability of calycosin on human PTC and its potential mechanisms. The B-CPAP cells were treated with calycosin, then cell proliferation, apoptosis and invasiveness were measured by CCK8 assay, flow cytometry, wound healing and transwell invasion assay, respectively. The cells were also performed by whole transcriptome microarray bioinformatics analysis. Apoptosis and autophagy-related markers or proteins were measured by qRT-PCR or western blot. Sestrin2-mediated AMPK/mTOR pathways were determined by western blot. We found that calycosin inhibited migration and invasion of B-CPAP cells and induced apoptosis (Bax/Bcl-2) and autophagy (LC3II/I, Beclin1) of B-CPAP cells. Differential expressed genes were screened between the calycosin-treated cells and control (524 genes upregulated and 328 genes downregulated). The pathway enrichment suggested that the role of calycosin in B-CPAP cells is closely related to apoptosis-related genes and p70S6 Kinase. Transmission electron microscopy found an increase in autophagosomes in calycosin-treated cells. Sestrin2 in human PTC tissues and B-CPAP cells was lower than in normal thyroid tissues and cells. And the pharmacological effects of calycosin in PTC cells were related to Sestrin2 activation, increased p-AMPK and inhibited p-mTOR and p-p70S6Kinase; these alterations were reversed when silencing Sestrin2. In conclusion, calycosin has an inhibitory effect on PTC via promoting apoptosis and autophagy through the Sestrin2/AMPK/mTOR pathway.

Mfn2-mediated mitochondrial fusion promotes autophagy and suppresses ovarian cancer progression by reducing ROS through AMPK/mTOR/ERK signaling

Mitochondrial dynamics are balanced fission and fusion events that regulate mitochondrial morphology, and alteration in these events results in mitochondrial dysfunction and contributes to many diseases, including tumorigenesis. Ovarian cancer (OC) cells exhibit fragmented mitochondria, but the mechanism by which mitochondrial dynamics regulators contribute to OC is considerably less clear. Here, we elucidated the potential role of Mfn2-mediated mitochondrial fusion in OC and present evidence that genetic or pharmacological activation of Mfn2 leads to mitochondrial fusion and reduces ROS generation, which correlates with reduced cell proliferation, invasion, migration, and EMT in OC cells. Also, increased mitochondrial fusion promotes the F-actin remodeling, reduces lamellipodia formation, and thus reduces EMT. Increased expression of Mfn2 triggers AMPK, promotes autophagy, reduces ROS, and suppresses OC progression by downregulating  the p-mTOR (2481 and 2448) and p-ERK axis. OC patients with higher Mfn2 expression have better survival than those with lower Mfn2 levels. Our findings demonstrate that restoration of Mfn2-mediated mitochondrial fusion suppressed OC progression and suggest that this process could be a potential strategy in OC treatment.

Sestrin2 in cancer: a foe or a friend?

Sestrin2 is a conserved antioxidant, metabolism regulator, and downstream of P53. Sestrin2 can suppress oxidative stress and inflammation, thereby preventing the development and progression of cancer. However, Sestrin2 attenuates severe oxidative stress by activating nuclear factor erythroid 2-related factor 2 (Nrf2), thereby enhancing cancer cells survival and chemoresistance. Sestrin2 inhibits endoplasmic reticulum stress and activates autophagy and apoptosis in cancer cells. Attenuation of endoplasmic reticulum stress and augmentation of autophagy hinders cancer development but can either expedite or impede cancer progression under specific conditions. Furthermore, Sestrin2 can vigorously inhibit oncogenic signaling pathways through downregulation of mammalian target of rapamycin complex 1 (mTORC1) and hypoxia-inducible factor 1-alpha (HIF-1α). Conversely, Sestrin2 decreases the cytotoxic activity of T cells and natural killer cells which helps tumor cells immune evasion. Sestrin2 can enhance tumor cells viability in stress conditions such as glucose or glutamine deficiency. Cancer cells can also upregulate Sestrin2 during chemotherapy or radiotherapy to attenuate severe oxidative stress and ER stress, augment autophagy and resist the treatment. Recent studies unveiled that Sestrin2 is involved in the development and progression of several types of human cancer. The effect of Sestrin2 may differ depending on the type of tumor, for instance, several studies revealed that Sestrin2 protects against colorectal cancer, whereas results are controversial regarding lung cancer. Furthermore, Sestrin2 expression correlates with metastasis and survival in several types of human cancer such as colorectal cancer, lung cancer, and hepatocellular carcinoma. Targeted therapy for Sestrin2 or regulation of its expression by new techniques such as non-coding RNAs delivery and vector systems may improve cancer chemotherapy and overcome chemoresistance, metastasis and immune evasion that should be investigated by future trials.

Flavonoids from Scutellaria barbata D. Don exert antitumor activity in colorectal cancer through inhibited autophagy and promoted apoptosis via ATF4/sestrin2 pathway

PURPOSE

Scutellaria barbata D. Don (SB), mainly containing flavonoids, has been frequently used for cancer treatment. However, little research has investigated the antitumor activity of flavonoids from SB (FSB). The current study aimed to assess the antitumor effect of TFSB and elucidate the probable underlying mechanism in vivo and in vitro.

STUDY DESIGN

FSB was prepared, and its chemical composition was characterized by HPLC-MS. Colorectal HCT116 cells were treated with various concentration of FSB. The viability, proliferation, apoptosis, migration, and autophagy of HCT116 cells were studied, as were further confirmed in tumor xenografts.

METHODS

Cell viability and proliferation were respectively examined by MTT and EdU staining. ROS was determined with DCFH-DA, and cell apoptosis was detected using flow cytometry. Transwell and wound-healing assays were performed to evaluate cell migration. Immunofluorescence was employed to evaluate sestrin2 and ATF4 level. The protein expressions of p-AMPK, p-ULK1, p-mTOR, 4E-BP1, LC3-I/II, cleaved-caspase-3, Bax, and bcl-2 were investigated by western blot. ATF4 was overexpressed in experiments to explore the role of ATF4/sestrin2 pathway in FSB-mediated efficacy.

RESULTS

FSB clearly reduced the cell viability, promoted ROS generation, and induced apoptosis in HCT116 cells by down-regulated Bcl-2, and increased cleaved-caspase-3 and Bax. Furthermore, FSB significantly inhibited migration of colorectal cells in a dose-dependent manner. Further mechanistic study indicated that FSB upregulated p-mTOR protein level, and reduced p-AMPK, p-ULK1, p-mTOR, p-4E-BP1 and LC3-I/II expression, which were major autophagy-related genes. In addition, FSB could cause downregulation of endogenous mTOR inhibitor sestrin2 and ATF4 expression. Transient overexpression of ATF4 resulted in mTOR and sestrin2 inhibition, and significantly compromised the effects of FSB on apoptosis and autophagy in HCT116 cells.

CONCLUSION

Our results reveal, for the first time, that FSB exerts antitumor activity through autophagy inhibition and apoptosis induction via ATF4/sestrin2 pathway in colorectal cancer cells. Scutellaria barbata D. Don may have great potential in the application for the prevention and treatment of human colorectal cancer.

Sestrin2 reduces cancer stemness via Wnt/β-catenin signaling in colorectal cancer

Background

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers in both men and women in China. In previous studies, Sestrin2 was demonstrated to have functions in CRC. However, the relationship between Sestrin2 and cancer stemness has not been reported.

Methods and results

To investigate the contribution of Sestrin2 in CRC, we performed bioinformatics analysis of The Cancer Genome Atlas datasets and found that Sestrin2 was downregulated in CRC. Using a lentivirus vector, we verified that Sestrin2 suppressed CRC cell proliferation, migration, and colony formation. Furthermore, sphere formation, flow cytometry, quantitative PCR, and western blot analysis verified the influence of Sestrin2 on cancer stemness, including the expression of cluster of differentiation 44, octamer-binding transcription factor 4, sex-determining region Y-Box 2, CXC chemokine receptor 4, and the Wnt pathway downstream factors β-catenin and c-Myc. Consistently, the Wnt pathway activator BML-284 partially rescued the effects of Sestrin2 on the expression of proteins related to cancer stemness. Furthermore, in a mouse xenoplant model, tumors expressing Sestrin2 were significantly reduced in size with corresponding changes in cancer stemness.

Conclusions

Collectively, our results suggest that Sestrin2 inhibits CRC cell progression by downregulating the Wnt signaling pathway. Thus, Sestrin2 may be a promising therapeutic target for CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02498-x.

The functions and roles of sestrins in regulating human diseases

Sestrins (Sesns), highly conserved stress-inducible metabolic proteins, are known to protect organisms against various noxious stimuli including DNA damage, oxidative stress, starvation, endoplasmic reticulum (ER) stress, and hypoxia. Sesns regulate metabolism mainly through activation of the key energy sensor AMP-dependent protein kinase (AMPK) and inhibition of mammalian target of rapamycin complex 1 (mTORC1). Sesns also play pivotal roles in autophagy activation and apoptosis inhibition in normal cells, while conversely promoting apoptosis in cancer cells. The functions of Sesns in diseases such as metabolic disorders, neurodegenerative diseases, cardiovascular diseases, and cancer have been broadly investigated in the past decades. However, there is a limited number of reviews that have summarized the functions of Sesns in the pathophysiological processes of human diseases, especially musculoskeletal system diseases. One aim of this review is to discuss the biological functions of Sesns in the pathophysiological process and phenotype of diseases. More significantly, we include some new evidence about the musculoskeletal system. Another purpose is to explore whether Sesns could be potential biomarkers or targets in the future diagnostic and therapeutic process.

A paradoxical role for sestrin 2 protein in tumor suppression and tumorigenesis

Sestrin 2, a highly conserved stress-induced protein, participates in the pathological processes of metabolic and age-related diseases. This p53-inducible protein also regulates cell growth and metabolism, which is closely related to malignant tumorigenesis. Sestrin 2 was reported to regulate various cellular processes, such as tumor cell proliferation, invasion and metastasis, apoptosis, anoikis resistance, and drug resistance. Although sestrin 2 is associated with colorectal, lung, liver, and other cancers, sestrin 2 expression varies among different types of cancer, and the effects and mechanisms of action of this protein are also different. Sestrin 2 was considered a tumor suppressor gene in most studies, whereas conflicting reports considered sestrin 2 an oncogene. Thus, this review aims to examine the literature regarding sestrin 2 in various cancers, summarize its roles in suppression and tumorigenesis, discuss potential mechanisms in the regulation of cancer, and provide a basis for follow-up research and potential cancer treatment development.

Pan-drug and drug-specific mechanisms of 5-FU, irinotecan (CPT-11), oxaliplatin, and cisplatin identified by comparison of transcriptomic and cytokine responses of colorectal cancer cells

Colorectal cancer (CRC) caused over 900,000 deaths worldwide in 2020. A majority of late-stage CRC patients are treated with 5-fluorouracil (5-FU) combined with either irinotecan (CPT-11), oxaliplatin, or both. Despite their widespread use, the mechanisms of efficacy and toxicity of these drugs remain incompletely understood. While previous work has investigated cellular responses to these agents individually, we directly compare the transcriptomic and cytokine profiles of HCT116 wild-type and p53-/- colorectal cancer cells treated with these drugs and report pan-drug, drug-specific, drug class-specific, p53-independent, and p53-dependent signatures. We observed downregulation of histone genes by 5-FU (that significantly correlates with improved survival in CRC patients) and upregulation of FOS and ATF3 by oxaliplatin (which may contribute to peripheral neuropathy). BTG2 was identified as a top gene upregulated by all four drugs, suggesting its critical role in the cellular response to chemotherapy in CRC. Soluble TRAILR2 (death receptor 5; DR5) is a decoy receptor for TRAIL, an apoptosis-inducing cytokine. TRAILR2 was down-regulated by oxaliplatin and 5-FU, was not affected by CPT-11, and was increased by cisplatin. There was an increase in IL-8 by oxaliplatin and increase in ferritin by cisplatin which may contribute to cancer cell survival. Novel drug-specific mechanisms of efficacy or toxicity identified in these signatures may be targeted with combination therapies or development of new targeted therapies. Together, the findings here contribute to our understanding of the molecular bases of efficacy and toxicity of chemotherapeutic agents often used for treatment of GI cancer such as CRC.

Potential Roles of Sestrin2 in Alzheimer's Disease: Antioxidation, Autophagy Promotion, and Beyond

Alzheimer’s disease (AD) is the most common age-related neurodegenerative disease. It presents with progressive memory loss, worsens cognitive functions to the point of disability, and causes heavy socioeconomic burdens to patients, their families, and society as a whole. The underlying pathogenic mechanisms of AD are complex and may involve excitotoxicity, excessive generation of reactive oxygen species (ROS), aberrant cell cycle reentry, impaired mitochondrial function, and DNA damage. Up to now, there is no effective treatment available for AD, and it is therefore urgent to develop an effective therapeutic regimen for this devastating disease. Sestrin2, belonging to the sestrin family, can counteract oxidative stress, reduce activity of the mammalian/mechanistic target of rapamycin (mTOR), and improve cell survival. It may therefore play a crucial role in neurodegenerative diseases like AD. However, only limited studies of sestrin2 and AD have been conducted up to now. In this article, we discuss current experimental evidence to demonstrate the potential roles of sestrin2 in treating neurodegenerative diseases, focusing specifically on AD. Strategies for augmenting sestrin2 expression may strengthen neurons, adapting them to stressful conditions through counteracting oxidative stress, and may also adjust the autophagy process, these two effects together conferring neuronal resistance in cases of AD.

Evaluation of Sestrin 2, Adiponectin, AMPK, and mTOR Genes Expression in Acute Myeloid Leukemia Patients

Background:

Effective treatment of acute myeloid leukemia (AML) is still controversial, therefore; a comprehensive understanding regarding the impaired cellular signaling pathways in AML can be useful in designing new therapeutic approaches. Among signaling pathways involved in AML, the mammalian target of rapamycin (mTOR) signaling pathway is of particular importance. While dysregulation of mTOR signaling has been reported in a wide range of patients with AML, but most studies have focused on mTOR downstream targets, and mTOR upstream targets have been overlooked.

Objective:

In this study, expression of mTOR genes and three upstream targets (5' adenosine monophosphate-activated protein kinase (AMPK, adiponectin, and sestrin 2) involved in mTOR signaling was investigated.

Materials and Methods:

In this study, expression of mTOR, AMPK, sestrin 2, and adiponectin genes in 60 patients with AML were evaluated compared to those of 30 healthy individuals as controls using the Real-Time polymerase chain reaction (Real-Time RT-PCR) method.

Results:

According to the results, there was a significant difference in the expression of all the studied genes in patients in comparison to the normal control group (P <0.05). Expression of the mTOR gene was increased, while expression of AMPK, sestrin 2, and adiponectin genes was decreased in the patients with AML. Mean expression of the genes (2-ΔCt) (AMPK, sestrin 2, adiponectin, and mTOR) was equal to 7.9, 3.2, 3.74, and 1.49 for controls and 6, 2.1, 2.83, and 2.64 for patients with AML, respectively.

Conclusions:

Given the decreased expression levels of sestrin 2, adiponectin, and AMPK genes as tumor inhibitors and the increased expression level of the mTOR gene as an oncogene in the patients with AML in our study, it is thought that disruption of this pathway may be involved in leukemogenesis and can be considered as an effective factor in the progression of cancer.

Sestrins as modulators of aging processes and diseases related to age

Sestrins are highly conserved proteins that regulate cell growth, metabolism, survival and proliferation under oxidative stress, genotoxic stress, hypoxia or endoplasmic reticulum stress. Sestrins affect cell signaling by inhibiting the production of reactive oxygen species, activating the AMP-activated protein kinase (AMPK), inhibiting the mTOR pathway and acting as a positive regulator of autophagy. Therefore, their protective role against cancer, metabolic disorders, cardiovascular diseases and neurodegeneration is increasingly being postulated. The article describes the mechanisms of action of sestrins and their meaning in aging and age-related diseases. The latest studies indicating their physiological significance and role in key signaling pathways controlling the cell metabolism and survival under stress conditions were also discussed.

Pharmacokinetic Analysis of Carnosic Acid and Carnosol in Standardized Rosemary Extract and the Effect on the Disease Activity Index of DSS-Induced Colitis

Rosemary extract (RE) is an approved food preservative in the European Union and contains dietary phytochemicals that are beneficial for gastrointestinal health. This study investigated the effects of RE on dextran sodium sulfate (DSS)-induced colitis and also determined the pharmacokinetics of dietary phytochemicals administered to mice via oral gavage. Individual components of rosemary extract were separated and identified by LC–MS/MS. The pharmacokinetics of two major diterpenes from RE, carnosic acid (CA) and carnosol (CL), administered to mice via oral gavage were determined. Then, the effect of RE pre-treatment on the disease activity index (DAI) of DSS-induced colitis in mice was investigated. The study determined that 100 mg/kg RE significantly improved DAI in DSS-induced colitis compared to negative control. Sestrin 2 protein expression, which increased with DSS exposure, was reduced with RE treatment. Intestinal barrier integrity was also shown to improve via fluorescein isothiocyanate (FITC)–dextran administration and Western blot of zonula occludens-1 (ZO-1), a tight junction protein. Rosemary extract was able to improve the DAI of DSS-induced colitis in mice at a daily dose of 100 mg/kg and showed improvement in the intestinal barrier integrity. This study suggests that RE can be an effective preventative agent against IBD.

Regulatory mechanisms of Sesn2 and its role in multi-organ diseases

Sestrin2 (Sesn2) is a powerful anti-oxidant that can prevent acute and chronic diseases. The role of Sesn2 has been thoroughly reviewed in liver, nervous system, and immune system diseases. However, there is a limited number of reviews that have summarized the effects of Sesn2 in heart and vascular diseases, and very less literature-based information is available on involvement of Sesn2 in renal and respiratory pathologies. This review summarizes the latest research on Sesn2 in multi-organ stress responses, with a particular focus on the protective role of Sesn2 in cardiovascular, respiratory, and renal diseases, emphasizing the potential therapeutic benefit of targeting Sesn2 in stress-related diseases.

SESTRINs: Emerging Dynamic Stress-Sensors in Metabolic and Environmental Health

Proper timely management of various external and internal stresses is critical for metabolic and redox homeostasis in mammals. In particular, dysregulation of mechanistic target of rapamycin complex (mTORC) triggered from metabolic stress and accumulation of reactive oxygen species (ROS) generated from environmental and genotoxic stress are well-known culprits leading to chronic metabolic disease conditions in humans. Sestrins are one of the metabolic and environmental stress-responsive groups of proteins, which solely have the ability to regulate both mTORC activity and ROS levels in cells, tissues and organs. While Sestrins are originally reported as one of several p53 target genes, recent studies have further delineated the roles of this group of stress-sensing proteins in the regulation of insulin sensitivity, glucose and fat metabolism, and redox-function in metabolic disease and aging. In this review, we discuss recent studies that investigated and manipulated Sestrins-mediated stress signaling pathways in metabolic and environmental health. Sestrins as an emerging dynamic group of stress-sensor proteins are drawing a spotlight as a preventive or therapeutic mechanism in both metabolic stress-associated pathologies and aging processes at the same time.

mTOR-Dependent Role of Sestrin2 in Regulating Tumor Progression of Human Endometrial Cancer

Simple Summary

Mammalian target of rapamycin complex 1 (mTORC1), a key controller of growth and environmental stress signaling, is frequently activated in human cancers. Sestrin2 (SESN2), a highly conserved stress-inducible protein, is one of the negative feedback mechanisms for inhibiting chronic activation of mTORC1. This study aimed to investigate the expression and clinical implications of SESN2 in endometrial cancer using an in vitro and in vivo approach. The analysis indicated increased levels of SESN2 and mTORC1 pathway activity in cancer tissues than in normal tissues. High SESN2 expression correlated with shorter patient survival duration. However, lentiviral overexpression of SESN2 and mTOR inhibitors suppressed cancer cell proliferation, migration, and epithelial–mesenchymal transition. Our study provides strong evidence for prognostic significance of SESN2, and its association with mTORC1 pathway and endometrial cancer growth. Thus, the results identified SESN2 as a potential therapeutic target in endometrial cancer.

Abstract

Oncogenic activation of the mammalian target of rapamycin complex 1 (mTORC1) leads to endometrial cancer cell growth and proliferation. Sestrin2 (SESN2), a highly conserved stress-inducible protein, is involved in homeostatic regulation via inhibition of reactive oxygen species (ROS) and mTORC1. However, the role of SESN2 in human endometrial cancer remains to be investigated. Here, we investigated expression, clinical significance, and underlying mechanisms of SESN2 in endometrial cancer. SESN2 was upregulated more in endometrial cancer tissues than in normal endometrial tissues. Furthermore, upregulation of SESN2 statistically correlated with shorter overall survival and disease-free survival in patients with endometrial cancer. SESN2 expression strongly correlated with mTORC1 activity, suggesting its impact on prognosis in endometrial cancer. Additionally, knockdown of SESN2 promoted cell proliferation, migration, and ROS production in endometrial cancer cell lines HEC-1A and Ishikawa. Treatment of these cells with mTOR inhibitors reversed endometrial cancer cell proliferation, migration, and epithelial–mesenchymal transition (EMT) marker expression. Moreover, in a xenograft nude mice model, endometrial cancer growth increased by SESN2 knockdown. Thus, our study provides evidence for the prognostic significance of SESN2, and a relationship between SESN2, the mTORC1 pathway, and endometrial cancer growth, suggesting SESN2 as a potential therapeutic target in endometrial cancer.

WITHDRAWN: GAS5 enhances natural killer cell-mediated killing by promoting ubiquitination of SESN2 in prostate cancer cells

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The function of miR-200 family in oxidative stress response evoked in cancer chemotherapy and radiotherapy

Since the beginning of the discovery of microRNAs (miRs), these molecules have attracted highly progressive attention due to their powerful regulatory roles in a broad spectrum of biological processes, including proliferation, differentiation, apoptosis and carcinogenesis. With regard to carcinogenesis, the miRs regulatory potency has been associated with cancer onset, progression, metastasis, diagnosis and therapeutic response. In this review we discuss the impact of miR-200 family on drug resistance development during anti-cancer therapy. Developing resistance to chemotherapeutic drugs as well as radiotherapy are major clinical obstacles in the successful therapeutic strategies to cancer treatment. Acquired cancer chemoresistance is a multifactorial phenomenon involving such factors as tumor type, tumor stage, cellular reactive oxygen species (ROS) level or ROS-responsive miRs profile. ROS level could influence the miRs expression level, which changes the cellular profile of the content of miRs. Such significant changes in the cellular miRs profile generate subsequent biological effects through the regulation of their target genes. This review outlines the interactions between ROS and miR-200 family in different kinds of cancers in response to chemotherapy.

The Emerging Role of Sestrin2 in Cell Metabolism, and Cardiovascular and Age-Related Diseases

Sestrins (Sesns), including Sesn1, Sesn2, and Sesn3, are cysteine sulfinyl reductases that play critical roles in the regulation of peroxide signaling and oxidant defense. Sesn2 is thought to regulate cell growth, metabolism, and survival response to various stresses, and act as a positive regulator of autophagy. The anti-oxidative and anti-aging roles of Sesn2 have been the focus of many recent studies. The role of Sesn2 in cellular metabolism and cardiovascular and age-related diseases must be analyzed and discussed. In this review, we discuss the physiological and pathophysiological roles and signaling pathways of Sesn2 in different stress-related conditions, such as oxidative stress, genotoxic stress, and hypoxia. Sesn2 is also involved in aging, cancer, diabetes, and ischemic heart disease. Understanding the actions of Sesn2 in cell metabolism and age-related diseases will provide new evidence for future experimental research and aid in the development of novel therapeutic strategies for Sesn2-related diseases.

Emerging Roles of Sestrins in Neurodegenerative Diseases: Counteracting Oxidative Stress and Beyond

Low levels of reactive oxygen species (ROS) are critical for the operation of regular neuronal function. However, heightened oxidative stress with increased contents of oxidation markers in DNA, lipids, and proteins with compromised antioxidant capacity may play a harmful role in the brain and may be implicated in the pathophysiology of neurodegenerative diseases. Sestrins, a family of evolutionarily-conserved stress-inducible proteins, are actively regulated by assorted stresses, such as DNA damage, hypoxia, and oxidative stress. Three highly homologous genes that encode sestrin1, sestrin2, and sestrin3 proteins exist in the genomes of vertebrates. Under stressful conditions, sestrins are activated with versatile functions to cope with different types of stimuli. A growing body of evidence suggests that sestrins, especially sestrin2, can counteract oxidative stress, lessen mammalian/mechanistic target of rapamycin (mTOR) expression, and promote cell survival, thereby playing a critical role in aging-related disorders including neurodegeneration. Strategies capable of augmenting sestrin expression may; thus, facilitate cell adaptation to stressful conditions or environments through stimulation of antioxidant response and autophagy process, which may carry clinical significance in neurodegenerative diseases.

Interactions between microRNA-200 family and Sestrin proteins in endometrial cancer cell lines and their significance to anoikis

In the present study, we intend to determine whether Sestrin proteins 1, 2, and 3 (SESN1-3) are targets of microRNA-200 family (miR-200) in endometrial cancer (EC) Ishikawa, AN3CA, KLE, and RL 95-2 cell lines and to investigate how these potential interactions influence anoikis resistance of EC cell lines. The luciferase reporter assay, qRT-PCR, and western blotting assays were used to verify whether SESN1-3 are direct targets of miR-200. Moreover, the anoikis assay and transient transfections of miR-200 mimics or inhibitors into EC cell lines were performed to evaluate the modulatory role of miR-200 and SESN proteins on anoikis resistance. We demonstrated that SESN2 protein is a direct target of mir-141 in KLE and RL-95-2 EC cell lines and the functional interaction of miR-141 and SESN2 protein has a downstream effect on anoikis resistance and SESN2 expression level in Ishikawa and AN3CA cell lines. Moreover, we have shown that SESN3 protein is a direct target of miR-200b, miR-200c, and miR-429 in Ishikawa, AN3CA, and KLE cell lines. Our results show that manipulation of miR-200b, miR-200c, and miR-429 expression patterns also has an influence on anoikis resistance in EC cell lines. In conclusion, we identified new interactions between miR-200 and the oxidative stress response SESN proteins that affect anoikis resistance in human EC cells.

Sestrins at the Interface of ROS Control and Autophagy Regulation in Health and Disease

Reactive oxygen species (ROS) and autophagy are two highly complex and interrelated components of cell physiopathology, but our understanding of their integration and their contribution to cell homeostasis and disease is still limited. Sestrins (SESNs) belong to a family of highly conserved stress-inducible proteins that orchestrate antioxidant and autophagy-regulating functions protecting cells from various noxious stimuli, including DNA damage, oxidative stress, hypoxia, and metabolic stress. They are also relevant modulators of metabolism as positive regulators of the key energy sensor AMP-dependent protein kinase (AMPK) and inhibitors of mammalian target of rapamycin complex 1 (mTORC1). Since perturbations in these pathways are central to multiple disorders, SESNs might constitute potential novel therapeutic targets of broad interest. In this review, we discuss the current understanding of regulatory and effector networks of SESNs, highlighting their significance as potential biomarkers and therapeutic targets for different diseases, such as aging-related diseases, metabolic disorders, neurodegenerative diseases, and cancer.

Carnosol, a dietary diterpene from rosemary (Rosmarinus officinalis) activates Nrf2 leading to sestrin 2 induction in colon cells

Background

Rosemary is abundant with phytochemicals and has recently been approved as an antioxidant food preservative in the European Union. The safety of rosemary is well established, however, the benefits on gastrointestinal health are less known. Our overall hypothesis is that the phytochemicals in rosemary including carnosol have the potential to promote gastrointestinal health by activation of the antioxidant sestrin-2 when consumed in our diet.

Methods

Colon cells HCT116 and SW480 were treated with carnosol and evaluated by MTT, immunofluorescence, ELISA, and Western blot analysis to understand the modulation of the PERK/Nrf2/Sestrin-2 pathway.

Results

Carnosol was found to modulate PERK and increase the concentration of nuclear Nrf2. Furthermore, a downstream marker of Nrf2 expression, Sestrin-2 was shown to be upregulated.

Conclusion

Based on these observations carnosol modulates the PERK and Nrf2 pathways along with increased expression of sestrin-2, a known stress inducible antioxidant.

Gene promoter and exon DNA methylation changes in colon cancer development - mRNA expression and tumor mutation alterations

BACKGROUND

DNA mutations occur randomly and sporadically in growth-related genes, mostly on cytosines. Demethylation of cytosines may lead to genetic instability through spontaneous deamination. Aims were whole genome methylation and targeted mutation analysis of colorectal cancer (CRC)-related genes and mRNA expression analysis of TP53 pathway genes.

METHODS

Long interspersed nuclear element-1 (LINE-1) BS-PCR followed by pyrosequencing was performed for the estimation of global DNA metlyation levels along the colorectal normal-adenoma-carcinoma sequence. Methyl capture sequencing was done on 6 normal adjacent (NAT), 15 adenomatous (AD) and 9 CRC tissues. Overall quantitative methylation analysis, selection of top hyper/hypomethylated genes, methylation analysis on mutation regions and TP53 pathway gene promoters were performed. Mutations of 12 CRC-related genes (APC, BRAF, CTNNB1, EGFR, FBXW7, KRAS, NRAS, MSH6, PIK3CA, SMAD2, SMAD4, TP53) were evaluated. mRNA expression of TP53 pathway genes was also analyzed.

RESULTS

According to the LINE-1 methylation results, overall hypomethylation was observed along the normal-adenoma-carcinoma sequence. Within top50 differential methylated regions (DMRs), in AD-N comparison TP73, NGFR, PDGFRA genes were hypermethylated, FMN1, SLC16A7 genes were hypomethylated. In CRC-N comparison DKK2, SDC2, SOX1 genes showed hypermethylation, while ERBB4, CREB5, CNTN1 genes were hypomethylated. In certain mutation hot spot regions significant DNA methylation alterations were detected. The TP53 gene body was addressed by hypermethylation in adenomas. APC, TP53 and KRAS mutations were found in 30, 15, 21% of adenomas, and in 29, 53, 29% of CRCs, respectively. mRNA expression changes were observed in several TP53 pathway genes showing promoter methylation alterations.

CONCLUSIONS

DNA methylation with consecutive phenotypic effect can be observed in a high number of promoter and gene body regions through CRC development.

Sestrin 2 suppresses cells proliferation through AMPK/mTORC1 pathway activation in colorectal cancer

Sestrin 2 is a conserved antioxidant protein that reduces reactive oxygen species (ROS) and inhibits mammalian target of rapamycin complex 1 (mTORC1). We previously showed that sestrin 2 is abnormally decreased in colorectal cancer (CRC). To elucidate the molecular mechanism behind the potential contribution of sestrin 2 to CRC, we used a lentiviral expression vector system to determine the effects of sestrin 2 overexpression on human CRC cells. We found that sestrin 2 overexpression decreased ROS production, inhibited cell growth, and stimulated apoptosis in two CRC cell lines. In parallel, expression of the proliferation marker PCNA was decreased, proapoptotic caspase 3, 7, and 9 levels were increased, and expression of the anti-apoptotic protein survivin was reduced. Sestrin 2 overexpression also activated the adenosine monophosphate-activated protein kinase (AMPK) pathway, and suppressed mTORC1 signaling. Treating CRC cells with compound C, an AMPK inhibitor, reversed or attenuated changes in proliferation, apoptosis, and signaling proteins of the AMPK/mTORC1 axis. In a xenograft mouse model, CRC growth was attenuated by sestrin 2 overexpression. These results suggest that sestrin 2 suppresses CRC cell growth through activation of the AMPK/mTORC1 pathway and induction of apoptosis, and could be a novel pharmacological target for the treatment of CRC.

Immunohistochemical evaluation of stress-responsive protein sestrin2 and its correlation with p53 mutational status in eyelid sebaceous gland carcinoma

BACKGROUND

p53 is a stress-activated tumour suppressor gene, and its mutation has been associated with solid tumours including non-melanoma skin cancers. Sestrin2 expression is associated with DNA damage and oxidative stress and has been described as a downstream target of p53 network. However, its role in sebaceous gland carcinoma (SGC) remains unexplored.

OBJECTIVES

To determine the role of p53 and its downstream target gene sestrin2 expression and p53 gene mutation status in SGC.

METHODS

Twenty cases of eyelid SGC tumour and circulating cell-free DNA (ccfDNA) were subjected to mutational analysis of p53 gene. p53 and sesrin2 expression was evaluated by immunohistochemistry. Results were correlated with the clinicopathological features of eyelid SGC.

RESULTS

p53 gene mutations was detected in 25% of the SGC cases. A C>T transition was identified in exon 6 in a single patient in both tumour and ccfDNA. A G>T transversion leading to amino acid change D259Y was seen in four patients. A splice site mutation affected a single case in exon 6. p53 expression was observed in 55% SGC. Loss of sestrin2 in 55% SGC cases correlated with poor tumour differentiation (P=0.0001), upper eyelid involvement (P=0.004), p53 mutation (P=0.039) and with mutant p53 expression (P=0.0001).

CONCLUSION

Sestrin2 expression was found to be significantly reduced in p53 mutated SGC cases and in cases with strong p53 nuclear immunopositivity, suggesting that loss of sestrin2 may be of biological significance in the development of SGC and as a key downstream component of p53 tumour suppression network in eyelid SGC.

Loss of sestrin 2 potentiates the early onset of age-related sensory cell degeneration in the cochlea

Sestrin 2 (SESN2) is a stress-inducible protein that protects tissues from oxidative stress and delays the aging process. However, its role in maintaining the functional and structural integrity of the cochlea is largely unknown. Here, we report the expression of SESN2 protein in the sensory epithelium, particularly in hair cells. Using C57BL/6J mice, a mouse model of age-related cochlear degeneration, we observed a significant age-related reduction in SESN2 expression in cochlear tissues that was associated with early onset hearing loss and accelerated age-related sensory cell degeneration that progressed from the base toward the apex of the cochlea. Hair cell death occurred by caspase-8 mediated apoptosis. Compared to C57BL/6J control mice, Sesn2 KO mice displayed enhanced expression of proinflammatory genes and activation of basilar membrane macrophages, suggesting that loss of SESN2 function provokes the immune response. Together, these results suggest that Sesn2 plays an important role in cochlear homeostasis and immune responses to stress.

SESN2 correlates with advantageous prognosis in hepatocellular carcinoma

Background

SESN2 plays important roles in the regulation of cell survival, cell protection, and tumor suppression. However, the relationship between SESN2 expression and the clinicopathological attributes of hepatocellular carcinoma (HCC) is barely investigated.

Methods

One-step quantitative reverse transcription PCR, Western blotting analysis in 15 fresh HCC tissues, and immunohistochemistry (IHC) analysis in a tissue microarray (TMA) containing 100 HCC cases were performed to examine SESN2 expression. Survival analyses by Cox regression method and Kaplan-Meier curve were performed to describe the overall survival of 100 HCC patients.

Results

The SESN2 expression in HCC tissues declined dramatically compared with the corresponding noncancerous tissues, and SESN2 expression was remarkably associated with HBV infection (p = 0.019), HCV infection (p = 0.001), and lymph node metastasis (p = 0.033). Survival analysis further demonstrated that SESN2 expression could serve as an independent prognostic biomarker for overall survival in univariate (p = 0.001) and multivariate analyses (p = 0.003).

Conclusion

The data are the first to indicate that SESN2 might be a novel prognostic marker for HCC and that elevated SESN2 expression predicts advantageous outcomes in HCC patients.

5-Fluorouracil inhibits cell migration by induction of Sestrin2 in colon cancer cells

5-Fluorouracil (5-FU) is a chemotherapeutic agent used in the treatment of colorectal cancer. In this study, we investigated whether 5-FU induces Sestrin2 (SESN2), an antioxidant enzyme, and the role of SESN2 in 5-FU action in colon cancer cells. We found that 5-FU upregulated SESN2 protein expression in both HCT116 and HT29 cells. It also increased transcripts of SESN1 and SESN2, but not of SESN3. Furthermore, we investigated whether production of reactive oxygen species (ROS) was involved in 5-FU-induced SESN2 expression. 5-FU did not increase ROS production nor affect Nrf2 phosphorylation and expression levels. Moreover, SESN2 upregulation by 5-FU was not prevented by pretreatment with antioxidants. Next, we investigated p53 levels after 5-FU treatment to elucidate the regulation of SESN2 by 5-FU. An increase in p53 levels was detected following 5-FU treatment; pifithrin-α, an inhibitor of p53 activation, reversed 5-FU-induced SESN2 expression. 5-FU prevented serum-induced in vitro cell migration, but knockdown of SESN2 or treatment with pifithrin-α reversed a 5-FU-mediated decrease in cell migration. Taken together, our results suggest that 5-FU increases SESN2 levels via a p53-dependent pathway, which contributes to inhibition of cancer cell migration in vitro.

Sestrin2 inhibits hypoxia-inducible factor-1α accumulation via AMPK-mediated prolyl hydroxylase regulation

Sestrin2 (SESN2) is an antioxidant protein that modulates cellular redox homeostasis through regeneration of peroxiredoxins. It has beneficial effects in oxidative or metabolic stress conditions as an upstream regulator of AMP-activated protein kinase (AMPK). Since hypoxia causes oxidative and metabolic stress, this study investigated the effect of SESN2 on signaling pathways altered by hypoxia in colon cancer cells. SESN2 overexpression in HEK293 cells inhibited hypoxia-inducible factor-1α (HIF-1α), which plays a crucial role in tumor growth and development in hypoxia. Moreover, infection with adenovirus-SESN2 (Ad-SESN2) decreased hypoxia or CoCl₂-induced HIF-1α accumulation in colorectal cancer cells. Ad-SESN2 also reduced CoCl₂-induced hypoxia response element (HRE)-luciferase activity and mRNA level of HIF-1α-driven genes. Furthermore, Ad-SESN2 infected cells showed anti-metastatic effects in serum-induced cell migration and invasion in vitro. Ad-SESN2 facilitated the ubiquitination of HIF-1α protein and increased hydroxyl-HIF-1α (OH-HIF-1α) level. In contrast, treatment with dimethyloxalylglycine (DMOG), an inhibitor of prolyl hydroxylase (PHD), reversed Ad-SESN2-induced OH-HIF-1α and subsequently suppressed HIF-1α level. The inhibitory effects of SESN2 on the serum-induced in vitro cell migration and invasion were also abrogated by DMOG treatment. Furthermore, knockdown of AMPKα reversed Ad-SESN2-mediated increase of OH-HIF-1α and inhibition of HIF-1α. Dominant-negative form of AMPK also restored the Ad-SESN2 mediated decrease in HIF-1α accumulation. Lastly, Ad-SESN2 suppressed tumor growth in a mouse xenograft model. Taken together, these results suggest that SESN2 increases degradation of HIF-1α via AMPK-PHD regulation that contributes to inhibition of in vitro and in vivo tumorigenesis.