SGK1 inhibition induces autophagy-dependent apoptosis via the mTOR-Foxo3a pathway

Therapeutic efficacy and anti-inflammatory mechanism of baicalein on endometriosis progression in patient-derived cell line and mouse model

BACKGROUND

Baicalein is a flavonoid extracted from the roots of Scutellaria baicalensis G. that has anti-inflammatory and antitumor effects. However, therapeutic mechanisms of baicalein in patients with endometriosis in vivo have yet to be elucidated. As a chronic inflammatory gynecological disease, endometriosis causes pain and infertility, and has no complete treatment to date. Current treatment strategies cause several side effects and have high recurrence rates.

PURPOSE

This study aimed to identify the in vivo therapeutic effects of baicalein on endometriosis and verify the action mechanisms of baicalein, focusing on regulating inflammation.

METHODS

In this study, an autologous transplant mouse model and patient-derived immortalized human ovarian endometriotic stromal cells (ihOESCs) were used to investigate the therapeutic activities of baicalein. The mouse model was administered with 40 mg/kg baicalein by oral gavage for 4 weeks, and the treatment outcomes of baicalein-treated mice were compared with vehicle- and dienogest-treated groups. ihOESCs were treated with 0-5 μg/ml baicalein for in vitro studies.

RESULTS

Baicalein significantly alleviated the progression of endometriosis in mouse models. Baicalein reduced the expression of proinflammatory cytokines in endometriotic lesions and ihOESCs, and cytokine expression and T cell proportions in mouse spleen. in vitro results showed that baicalein increased mitochondrial calcium flux and induced mitochondrial depolarization and ROS generation in ihOESCs. Ultimately, baicalein inactivated the MAPK/PI3K signaling and induced cell death in ihOESCs.

CONCLUSION

In conclusion, baicalein effectively attenuated the progression of endometriosis through its anti-inflammatory activities. Baicalein can be an alternative or supplemental treatment for endometriosis to ameliorate the side effects of hormonal therapy.

Role of KDM2B epigenetic factor in regulating calcium signaling in prostate cancer cells

KDM2B, a histone lysine demethylase, is expressed in a plethora of cancers. Earlier studies from our group, have showcased that overexpression of KDM2B in the human prostate cancer cell line DU-145 is associated with cell adhesion, actin reorganization, and improved cancer cell migration. In addition, we have previously examined changes of cytosolic Ca2+, regulated by the pore-forming proteins ORAI and the Ca2+ sensing stromal interaction molecules (STIM), via store-operated Ca2+ entry (SOCE) in wild-type DU-145. This study sought to evaluate the impact of KDM2B overexpression on the expression of key molecules (SGK1, Nhe1, Orai1, Stim1) and SOCE. Furthermore, this is the first study to evaluate KDM2B expression in circulating tumor cells (CTCs) from patients with prostate cancer. mRNA levels for SGK1, Nhe1, Orai1, and Stim1 were quantified by RT-PCR. Calcium signals were measured in KDM2B-overexpressing DU-145 cells, loaded with Fura-2. Blood samples from 22 prostate cancer cases were scrutinized for KDM2B expression using immunofluorescence staining and the VyCAP system. KDM2B overexpression in DU-145 cells increased Orai1, Stim1, and Nhe1 mRNA levels and significantly decreased Ca2+ release. KDM2B expression was examined in 22 prostate cancer patients. CTCs were identified in 45 % of these patients. 80 % of the cytokeratin (CK)-positive patients and 63 % of the total examined CTCs exhibited the (CK + KDM2B + CD45-) phenotype. To conclude, this study is the first to report increased expression of KDM2B in CTCs from patients with prostate cancer, bridging in vitro and preclinical assessments on the potentially crucial role of KDM2B on migration, invasiveness, and ultimately metastasis in prostate cancer.

Traditional Chinese medicine and mitophagy: A novel approach for cardiovascular disease management

BACKGROUND

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, imposing an enormous economic burden on individuals and human society. Laboratory studies have identified several drugs that target mitophagy for the prevention and treatment of CVD. Only a few of these drugs have been successful in clinical trials, and most studies have been limited to animal and cellular models. Furthermore, conventional drugs used to treat CVD, such as antiplatelet agents, statins, and diuretics, often result in adverse effects on patients' cardiovascular, metabolic, and respiratory systems. In contrast, traditional Chinese medicine (TCM) has gained significant attention for its unique theoretical basis and clinical efficacy in treating CVD.

PURPOSE

This paper systematically summarizes all the herbal compounds, extracts, and active monomers used to target mitophagy for the treatment of CVD in the last five years. It provides valuable information for researchers in the field of basic cardiovascular research, pharmacologists, and clinicians developing herbal medicines with fewer side effects, as well as a useful reference for future mitophagy research.

METHODS

The search terms "cardiovascular disease," "mitophagy," "herbal preparations," "active monomers," and "cardiac disease pathogenesis" in combination with "natural products" and "diseases" were used to search for studies published in the past five years until January 2024.

RESULTS

Studies have shown that mitophagy plays a significant role in the progression and development of CVD, such as atherosclerosis (AS), heart failure (HF), myocardial infarction (MI), myocardial ischemia/reperfusion injury (MI/RI), cardiac hypertrophy, cardiomyopathy, and arrhythmia. Herbal compound preparations, crude extracts, and active monomers have shown potential as effective treatments for these conditions. These substances protect cardiomyocytes by inducing mitophagy, scavenging damaged mitochondria, and maintaining mitochondrial homeostasis. They display notable efficacy in combating CVD.

CONCLUSION

TCM (including herbal compound preparations, extracts, and active monomers) can treat CVD through various pharmacological mechanisms and signaling pathways by inducing mitophagy. They represent a hotspot for future cardiovascular basic research and a promising candidate for the development of future cardiovascular drugs with fewer side effects and better therapeutic efficacy.

Sodium chloride promotes macrophage pyroptosis and aggravates rheumatoid arthritis by activating SGK1 through GABA receptors Slc6a12

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by synovial inflammation and the production of autoantibodies. Previous studies have indicated an association between high-salt diets (HSD) and an increased risk of RA, yet the underlying mechanisms remain unclear. Macrophage pyroptosis, a pro-inflammatory form of cell death, plays a pivotal role in RA. In this study, we demonstrate that HSD exacerbates the severity of arthritis in collagen-induced arthritis (CIA) mice, correlating with macrophage infiltration and inflammatory lesions. Given the significant alterations observed in macrophages from CIA mice subjected to HSD, we specifically investigate the impact of HSD on macrophage responses in the inflammatory milieu of RA. In our in vitro experiments, pretreatment with NaCl enhances LPS-induced pyroptosis in RAW.264.7 and THP-1 cells through the p38 MAPK/NF-κB signaling pathway. Subsequent experiments reveal that Slc6a12 inhibitors and SGK1 silencing inhibit sodium-induced activation of macrophage pyroptosis and the p38 MAPK/NF-κB signaling pathway, whereas overexpression of the SGK1 gene counteracts the effect of sodium on macrophages. In conclusion, our findings verified that high salt intake promotes the progression of RA and provided a detailed elucidation of the activation of macrophage pyroptosis induced by sodium transportation through the Slc6a12 channel.

The role of serum-glucocorticoid regulated kinase 1 in reproductive viability: implications from prenatal programming and senescence

OBJECTIVE

Organisms and cellular viability are of paramount importance to living creatures. Disruption of the balance between cell survival and apoptosis results in compromised viability and even carcinogenesis. One molecule involved in keeping this homeostasis is serum-glucocorticoid regulated kinase (SGK) 1. Emerging evidence points to a significant role of SGK1 in cell growth and survival, cell metabolism, reproduction, and life span, particularly in prenatal programming and reproductive senescence by the same token. Whether the hormone inducible SGK1 kinase is a major driver in the pathophysiological processes of prenatal programming and reproductive senescence?

METHOD

The PubMed/Medline, Web of Science, Embase/Ovid, and Elsevier Science Direct literature databases were searched for articles in English focusing on SGK1 published up to July 2023 RESULT: Emerging evidence is accumulating pointing to a pathophysiological role of the ubiquitously expressed SGK1 in the cellular and organismal viability. Under the regulation of specific hormones, extracellular stimuli, and various signals, SGK1 is involved in several biological processes relevant to viability, including cell proliferation and survival, cell migration and differentiation. In line, SGK1 contributes to the development of germ cells, embryos, and fetuses, whereas SGK1 inhibition leads to abnormal gametogenesis, embryo loss, and truncated reproductive lifespan.

CONCLUTION

SGK1 integrates a broad spectrum of effects to maintain the homeostasis of cell survival and apoptosis, conferring viability to multiple cell types as well as both simple and complex organisms, and thus ensuring appropriate prenatal development and reproductive lifespan.

LncRNA LBX2-AS1 promotes proliferation and migratory capacity of clear cell renal cell carcinoma through mitophagy

BACKGROUND

Long non-coding RNAs (lncRNAs) have been extensively investigated in the field of cancer, among which, lncRNA ladybird homeobox 2-antisense RNA 1 (LBX2-AS1) has been demonstrated to exert carcinogenic effects on a variety of malignancies. However, the biological functions of LBX2-AS1 in clear cell renal cell carcinoma (ccRCC) have not been explicitly elucidated.

METHODS

Arraystar lncRNA chip and qRT-PCR verify the expression of LncRNA LBX2-AS1 in ccRCC. CCK-8 assay and cell cloning assay were used to assess the proliferative capacity of ccRCC cells. Migration abilities were quantified by scratch assay and transwell assay. Potential molecular signaling pathways were determined by high-throughput whole transcriptomics analysis. WB analysis was performed to validate the relationship between LBX2-AS1 and key molecules of mitophagy pathway. The effect of LBX2-AS1 on mitophagy was observed by laser confocal microscopy. Rescue experiments further validated the role of downstream gene FOXO3A in the LBX2-AS1 signaling pathway. Finally, the authentic effect of LBX2-AS1 was verified in vivo.

RESULTS

LncRNA LBX2-AS1 was over expressed in ccRCC tissues and could enhance the proliferation and migration of ccRCC cells. Autophagic pathway was identified as a possible mechanism involved in the oncogenic effect of LBX2-AS1. Mitophagy levels were observed in LBX2-AS1 low-expressing cells through laser confocal microscopy. Knockdown of LBX2-AS1 significantly elevated mitophagy levels as observed using laser confocal microscopy and led to FOXOA3 decreasing in and BNIP3L and LC3 enrichment. Meanwhile, LBX2-AS1 knocking down dampened the proliferation of ccRCC cells in vivo.

The role of serum and glucocorticoid-regulated kinase 1 in cellular signaling: Implications for drug development

Serum and glucocorticoid-regulated kinase 1 (SGK1) is a ubiquitously expressed protein belonging to the Ser/Thr kinase family. It regulates diverse physiological processes, including epithelial sodium channel activity, hypertension, cell proliferation, and insulin sensitivity. Due to its significant role in the pathogenesis of numerous diseases, SGK1 can be exploited as a potential therapeutic target to address challenging health problems. SGK1 is associated with the development of obesity, and its overexpression enhances the sodium-glucose co-transporter 1 activity, which absorbs intestinal glucose. This review highlighted the detailed functional significance of SGK1 signaling and role in different diseases and subsequent therapeutic targeting. We aim to provide deeper mechanistic insights into understanding the pathogenesis and recent advancements in the SGK1 targeted drug development process. Small-molecule inhibitors are being developed with excellent binding affinity and improved SGK1 inhibition with desired selectivity. We have discussed small molecule inhibitors designed explicitly as potent SGK1 inhibitors and their therapeutic implications in various diseases. We further addressed the therapeutic potential and mechanism of action of these SGK1 inhibitors and provided a strong scientific foundation for developing effective therapeutics.

Identification of a new structural family of SGK1 inhibitors as potential neuroprotective agents

SGK1 is a serine/threonine kinase involved in several neurodegenerative-related pathways such as apoptosis, neuroinflammation, ionic channel regulation, and autophagy, among others. Despite its potential role as a pharmacological target against this kind of diseases, there are no reported inhibitors able to cross the BBB so far, being a field yet to be explored. In this context, a structure-based virtual screening against this kinase was performed, pointing out the deazapurine moiety as an interesting and easy-to-derivatize scaffold. Moreover, these inhibitors are able to i) exert neuroprotection in an in vitro model of AD and ii) block mitophagy in a PRKN-independent manner, reinforcing the hypothesis of SGK1 inhibitors as neuroprotective chemical tools.

PPARγ activation by fisetin mitigates vascular smooth muscle cell senescence via the mTORC2-FoxO3a-autophagy signaling pathway

Cellular senescence is caused by diverse stimuli and contributes to cardiovascular diseases. Several studies have indicated that PPARγ acts as a key mediator of lipid metabolism and shown that it has a protective effect on vascular biology. Nevertheless, the mechanism responsible for the anti-aging effects of PPARγ has not been fully elucidated in vascular smooth muscle cell (VSMC). Furthermore, although mTOR complex 2 (mTORC2) is known to be involved in cellular senescence and autophagy, relatively few studies have investigated its effects as compared with mTOR complex 1 (mTORC1). Therefore, we focused on mTORC2 function and investigated the relationship between PPARγ and mTORC2, and the anti-aging mechanism in VSMC. We found PPARγ activation dose-dependently mitigated the hydrogen peroxide (H2O2)-induced senescence. Treatment of fisetin induced the translocation of PPARγ from cytosol to nuclear and inhibited VSMC senescence. Moreover, activated PPARγ increased PTEN transcription, leading to inhibition of the mTORC2 signaling pathway. We determined mTORC2 activation contributed to senescence by suppressing the FoxO3a-autophagy signaling pathway, and dual knockdown of mTORC1 and mTORC2 decreased cellular senescence and increased autophagy activation more than respective single knockdown. Finally, fisetin acted as a PPARγ activator and inhibited VSMC senescence through the mTORC2-FoxO3a-autophagy signaling pathway. These results demonstrate PPARγ is associated with cellular senescence and that fisetin has an anti-aging effect via PPARγ activation and mTORC2 inhibition in VSMC. These results demonstrate that the mTORC2 signaling pathway regulates autophagy and cellular senescence, which suggests mTORC2 should be considered a significant target for preventing cellular senescence and age-related diseases.

miR-3200 accelerates the growth of liver cancer cells by enhancing Rab7A

Researches indicate miR-3200 is closely related to tumorigenesis, However, the role of miR-3200 in human hepatocarcinogenesis is still unclear. In this study, we clearly demonstrate that miR-3200 accelerates the growth of liver cancer cells in vivo and in vitro. Obviously, these findings are noteworthy that miR-3200 affects the transcriptional regulation for several genes, including DSP，BABAM2, Rab7A,SQSTM1,PRKAG2,CDK1,ABCE1,BECN1,PTEN,UPRT. And miR-3200 affects the transcriptional ability of several genes, such as, upregulating CADPS, DSP,FBXO32, PPCA,SGK1, PATXN7L1, PLK2,ITGB5,FZD3,HOXC8,HSPA1A,C-Myc,CyclnD1,CyclinE,PCNA and down -regulating SUV39H1, MYO1G, OLFML3, CBX5, PPDE2A, HOXA7, RAD54L, CDC45,SHMT7,MAD2L1,P27,IQGAP3,PTEN,P57,SCAMP3,etc...On the other hand, it is obvious that miR-3200 affects the translational ability of several genes, such as, upregulating GNS,UPRT,EIFAD,YOS1,SGK1,K-Ras,PKM2,C-myc,Pim1,CyclinD1,mTOR,erbB-2,CyclinE,PCNA,RRAS,ARAF,RAPH1,etc.. and down-regulating KDM2A, AATF, TMM17B, RAB8B, MYO1G,P21WAF1/Cip1,GADD45,PTEN,P27,P18,P57,SERBP1,RPL34,UFD1,Bax,ANXA6,GSK3β. Strikingly, miR-3200 affects some signaling pathway in liver cancer, including carbon metabolism signaling pathway, DNA replication pathway, FoxO signaling pathway, Hippo signaling pathway, serine and threonine metabolism signaling pathway, mTOR signaling pathway, Fatty acid biosynthesis signaling pathway, carcinogenesis-receptor activation signaling pathway, autophagy signaling pathway. Furthermore, our results suggest that miR-3200 enhances expression of RAB7A, and then Rab7A regulates the carcinogenic function of miR-3200 by increasing telomere remodeling in human liver cancer. These results are of great significance for the prevention and treatment of human liver cancer.

Circular RNA COL1A2 Mediates High Glucose-Induced Oxidative Stress and Pyroptosis by Regulating MiR-424-5p/SGK1 in Diabetic Nephropathy

Diabetic nephropathy (DN) represents a major diabetes-related complication, which could undermine renal function. CircCOL1A2 has been previously reported to show abnormal expression during DN. However, its functional role in the progression of DN, as well as the potential molecular mechanisms, remains unclear. The present work examined the expression of circCOL1A2 in the plasma of DN patients, and employed high glucose (HG)-challenged HK-2 cells as the in vitro cell model of hyperglycemia (HG)-induced DN. CircCOL1A2 was silenced using siRNA in HK-2 cells to clarify the functional engagement of circCOL1A2 in HG-induced DN. We examined the roles of circCOL1A2 in regulating oxidative stress by measuring reactive oxygen species (ROS), lipid peroxidation, and superoxide dismutase (SOD) levels. Besides, the effects of circCOL1A2 silencing on pyroptosis were investigated by RT-qPCR, western blot (WB), and ELISA assays. StarBase (version 2.0) was used to identify the downstream effector of circCOL1A2, and their interactions were further verified through dual-luciferase reporter analysis, RNA pull-down assays, and RNA immunoprecipitation (RIP) assay. CircCOL1A2 was highly expressed in DN patients and HG-induced HK-2 cells. Knocking down circCOL1A2 alleviated oxidative stress and pyroptosis upon HG treatment. In addition, we demonstrated that circCOL1A2 knockdown could promote miR-424-5p expression while inhibiting Serum/Glucocorticoid Regulated Kinase 1 (SGK1) level. Furthermore, miR-424-5p inhibitor or SGK1 overexpression impaired the effects of circCOL1A2 knockdown on HG-induced oxidative stress and pyroptosis. Hence, our results demonstrated that the circCOL1A2 mediates HG-exposed pyroptosis and oxidative stress through modulating miR-424-5p/SGK1 axis in diabetic nephropathy, indicating that silencing circCOL1A2 is a potential intervention strategy for DN management.

Exosomal miR-222-3p contributes to castration-resistant prostate cancer by activating mTOR signaling

Despite the clinical benefits of androgen deprivation therapy, most patients with advanced androgen-dependent prostate cancer (ADPC) eventually relapse and progress to lethal androgen-independent prostate cancer (AIPC), also termed castration-resistant prostate cancer (CRPC). MiRNAs can be packaged into exosomes (Exos) and shuttled between cells. However, the roles and mechanisms of exosomal miRNAs involved in CRPC progression have not yet been fully elucidated. Here, we find that miR-222-3p is elevated in AIPC cells, which results in remarkable enhancement of cell proliferation, migration, and invasion ability. Furthermore, Exos released by AIPC cells can be uptaken by ADPC cells, thus acclimating ADPC cells to progressing to more aggressive cell types in vitro and in vivo through exosomal transfer of miR-222-3p. Mechanistically, Exos-miR-222-3p promoted ADPC cells transformed to AIPC-like cells, at least in part, by activating mTOR signaling through targeting MIDN. Our results show that AIPC cells secrete Exos containing miRNA cargo. These cargos can be transferred to ADPC cells through paracrine mechanisms that have a strong impact on cellular functional remodeling. The current work underscores the great therapeutic potential of targeting Exo miRNAs, either as a single agent or combined with androgen receptor pathway inhibitors for CRPC treatment.

Emerging proteins involved in castration‑resistant prostate cancer via the AR‑dependent and AR‑independent pathways (Review)

Despite achieving optimal initial responses to androgen deprivation therapy, most patients with prostate cancer eventually progress to a poor prognosis state known as castration‑resistant prostate cancer (CRPC). Currently, there is a notable absence of reliable early warning biomarkers and effective treatment strategies for these patients. Although androgen receptor (AR)‑independent pathways have been discovered and acknowledged in recent years, the AR signaling pathway continues to play a pivotal role in the progression of CRPC. The present review focuses on newly identified proteins within human CRPC tissues. These proteins encompass both those involved in AR‑dependent and AR‑independent pathways. Specifically, the present review provides an in‑depth summary and analysis of the emerging proteins within AR bypass pathways. Furthermore, the significance of these proteins as potential biomarkers and therapeutic targets for treating CRPC is discussed. Therefore, the present review offers valuable theoretical insights and clinical perspectives to comprehensively enhance the understanding of CRPC.

The rules and regulatory mechanisms of FOXO3 on inflammation, metabolism, cell death and aging in hosts

The FOX family of transcription factors was originally identified in 1989, comprising the FOXA to FOXS subfamilies. FOXO3, a well-known member of the FOXO subfamily, is widely expressed in various human organs and tissues, with higher expression levels in the ovary, skeletal muscle, heart, and spleen. The biological effects of FOXO3 are mostly determined by its phosphorylation, which occurs in the nucleus or cytoplasm. Phosphorylation of FOXO3 in the nucleus can promote its translocation into the cytoplasm and inhibit its transcriptional activity. In contrast, phosphorylation of FOXO3 in the cytoplasm leads to its translocation into the nucleus and exerts regulatory effects on biological processes, such as inflammation, aerobic glycolysis, autophagy, apoptosis, oxidative stress, cell cycle arrest and DNA damage repair. Additionally, FOXO3 isoform 2 acts as an important suppressor of osteoclast differentiation. FOXO3 can also interfere with the development of various diseases, including inhibiting the proliferation and invasion of tumor cells, blocking the production of inflammatory factors in autoimmune diseases, and inhibiting β-amyloid deposition in Alzheimer's disease. Furthermore, FOXO3 slows down the aging process and exerts anti-aging effects by delaying telomere attrition, promoting cell self-renewal, and maintaining genomic stability. This review suggests that changes in the levels and post-translational modifications of FOXO3 protein can maintain organismal homeostasis and improve age-related diseases, thus counteracting aging. Moreover, this may indicate that alterations in FOXO3 protein levels are also crucial for longevity, offering new perspectives for therapeutic strategies targeting FOXO3.

Luteolin inhibits triple-negative breast cancer by inducing apoptosis and autophagy through SGK1-FOXO3a-BNIP3 signaling

Background: Triple-negative breast cancer (TNBC) is one of the most prominent neoplasm disorders and lacks efficacious treatments yet. Luteolin (3',4',5,7-tetrahydroxyflavone), a natural flavonoid commonly presented in plants, has been reported to delay the progression of TNBC. However, the precise mechanism is still elusive. We aimed to elucidate the inhibition and molecular regulation mechanism of luteolin on TNBC. Methods: The effects of luteolin on the biological functions of TNBC cells were first evaluated using the corresponding assays for cell counting kit-8 assay, flow cytometry, wound-healing assay, and transwell migration assay, respectively. The mechanism of luteolin on TNBC cells was then analyzed by RNA sequencing and verified by RT-qPCR, Western blot, transmission electron microscopy, etc. Finally, in vivo mouse tumor models were constructed to further confirm the effects of luteolin on TNBC. Results: Luteolin dramatically suppressed cell proliferation, invasion, and migration while favoring cell apoptosis in a dose- and time-dependent manner. In TNBC cells treated with luteolin, SGK1 and AKT3 were significantly downregulated while their downstream gene BNIP3 was upregulated. According to the results of 3D modeling, the direct binding of luteolin to SGK1 was superior to that of AKT3. The inhibition of SGK1 promoted FOXO3a translocation into the nucleus and led to the transcription of BNIP3 both in vitro and in vivo, eventually facilitating the interaction between BNIP3 and apoptosis and autophagy protein. Furthermore, the upregulation of SGK1, induced by luteolin, attenuated the apoptosis and autophagy of the TNBC. Conclusion: Luteolin inhibits TNBC by inducing apoptosis and autophagy through SGK1-FOXO3a-BNIP3 signaling.

mTOR in programmed cell death and its therapeutic implications

Mechanistic target of rapamycin (mTOR), a highly conserved serine/threonine kinase, is involved in cellular metabolism, protein synthesis, and cell death. Programmed cell death (PCD) assists in eliminating aging, damaged, or neoplastic cells, and is indispensable for sustaining normal growth, fighting pathogenic microorganisms, and maintaining body homeostasis. mTOR has crucial functions in the intricate signaling pathway network of multiple forms of PCD. mTOR can inhibit autophagy, which is part of PCD regulation. Cell survival is affected by mTOR through autophagy to control reactive oxygen species production and the degradation of pertinent proteins. Additionally, mTOR can regulate PCD in an autophagy-independent manner by affecting the expression levels of related genes and phosphorylating proteins. Therefore, mTOR acts through both autophagy-dependent and -independent pathways to regulate PCD. It is conceivable that mTOR exerts bidirectional regulation of PCD, such as ferroptosis, according to the complexity of signaling pathway networks, but the underlying mechanisms have not been fully explained. This review summarizes the recent advances in understanding mTOR-mediated regulatory mechanisms in PCD. Rigorous investigations into PCD-related signaling pathways have provided prospective therapeutic targets that may be clinically beneficial for treating various diseases.

FOXO signaling pathway participates in oxidative stress-induced histone deacetylation

High concentrations of antioxidants can exert pro-oxidative effects, elevate the level of intracellular reactive oxygen species (ROS), and cause oxidative stress in cells. We previously found that high concentrations of curcumin, a natural polyphenol antioxidant, elevated ROS levels and upregulated the expression of histone deacetylase 1 (HDAC1) in human gastric cancer cells (hGCCs); however, its potential mechanisms and subsequent functions have not been elucidated. In the present study, we treated hGCCs with high concentrations of curcumin, detected several indicators of oxidative stress, and investigated the mechanism of curcumin-treatment-mediated HDAC1 upregulation and its effect on histone acetylation. The results showed that curcumin treatment caused oxidative stress in hGCCs and upregulated HDAC1/2 expression via the forkhead box O (FOXO) signaling pathway, ultimately leading to the deacetylation of histones in hGCCs. Moreover, HDAC1/2 mediates the deacetylation of FOXOs and promotes their transcription activities, implying a positive feedback loop between FOXOs and HDAC1/2. These findings present a mechanism by which oxidative stress induces histone deacetylation in hGCCs.

Low-dose dexamethasone promotes osteoblast viability by activating autophagy via the SGK1/FOXO3a signaling pathway

Autophagy contributes to bone homeostasis and development under physiological conditions. Although previous studies have demonstrated the induction of the autophagy machinery by endogenous glucocorticoids (GCs), the precise mechanisms involved have not yet been clarified. The current study aimed to explore the effect of a low dose of GC (10^-8 M dexamethasone, Dex) on autophagy in mouse embryonic osteoblastic precursor cells (MC3T3-E1 cells) and the potential mechanisms. The results showed that 10^-8 M Dex induced significant time-dependent increases in the expression and activation of serum- and glucocorticoid-induced kinase-1 (SGK1) in MC3T3-E1 cells and that these effects were accompanied by increased cell viability and decreased apoptosis. The autophagy inhibitor 3-MA significantly inhibited Dex-mediated promotion of viability. Moreover, Dex increased LC3II and Beclin-1 levels and decreased SQSTM/p62 levels in a time-dependent manner, and these effects were attenuated by pretreatment with 3-MA. Transfection of Dex-treated MC3T3-E1 cells with shRNA-SGK1 resulted in a significant reduction in cell viability and an increase in apoptosis. 3-MA further exacerbated these effects of SGK1 inhibition. Knocking down SGK1 before Dex exposure significantly reduced the phosphorylated forkhead box O3a (p-FOXO3a)/FOXO3 ratio, suppressed LC3II and Beclin-1 levels, and increased SQSTM/p62 levels in MC3T3-E1 cells, and these effects were amplified by 3-MA. In conclusion, the results revealed that low-dose GC treatment increased osteoblast viability by activating autophagy via the SGK1/FOXO3a pathway.

Reproductive performance and transcriptome analysis of ovaries at different parities in female rabbits

This study investigated the reproductive performance and ovarian molecular regulation associated with parity in commercial rabbit systems. The pregnancy data of 658 female rabbits from the first to sixth parities (P1 to P6) under the same mating pattern were analyzed, showing a significant decrease in the conception rate in P6. Compared to P1 (N = 120) and P2 (N = 105), P6 (N = 99) had significantly lower performance indices in terms of total litter size, live litter size, survival rate at birth, and weight of 3 and 5 wk old kits (P < 0.05). Using H&E staining, we found that the ovarian primordial follicle reservoir of P6 was significantly lower than that of P1 and P2, and the number of atretic follicles at P6 was significantly higher (P < 0.05). Blood (N = 30 per group) and ovaries (N = 6 per group) in P1, P2, and P6 were collected for measurement of the serum anti-oxidant capacity and indices of ovarian function by ELISA. It was found that serum glutathione, ovarian Klotho protein, and telomeres of P1 and P2 were significantly higher than those of P6 (P < 0.05). The serum levels of ROS and MDA at P1 and P2 were significantly lower than those at P6 (P < 0.05). Additionally, transcriptome analysis showed 213 up-regulated and 747 down-regulated differentially expressed genes (DEGs) between P2 and P6 ovaries. Several DEGs were related to reproduction, including CYP21A2, PTGFR, SGK1, PIK3R6, and SRD5A2. These results demonstrate the influence of parity on reproduction in female rabbits, reflected in a loss of follicle reservoir, disordered levels of anti-oxidants, and indices associated with ovarian function and molecular regulation. This study provides a basis for the strategies to increase reproductive rate in female rabbits.

The Serum- and Glucocorticoid-Inducible Kinase 1 (SGK1) as a Novel Therapeutic Target in Mantle Cell Lymphoma

INTRODUCTION

Mantle cell lymphoma (MCL) is an aggressive and incurable B-cell-derived malignant disease. MCL is treated using general chemotherapy; however, disease progression and relapse are common; thus, the development of novel therapeutic targets for treatment of MCL is urgently required. Serum- and glucocorticoid-inducible kinase 1 (SGK1) is involved in various cellular activities, and its dysregulation contributes to the pathogenesis of multiple types of cancer. However, little is known regarding its functional roles and associated molecular mechanisms in MCL.

METHODS

SGK1 inhibition mediated by either shRNA or treatment with SGK1 inhibitor (GSK650394) was conducted in MCL cell lines. Western blotting analysis was performed to figure out the expression of related proteins. MCL-cell-derived xenograft models were constructed to evaluate the anti-tumor effects of SGK1 inhibition or/and Bruton's tyrosine kinase (BTK) inhibition in vivo.

RESULTS

In this study, it was shown that inhibition of SGK1 significantly reduced cell proliferation, invasion and migration, increased apoptosis and blocked cell cycle progression in MCL cells. Furthermore, SGK1 inhibition significantly reduced the activation of ERK, AKT/mTOR, JAK2/STAT3 and the NF-κB signaling pathways. Using MCL-cell-derived xenograft mice models, SGK1 inhibition decreased tumor cell proliferation and tumor growth. Importantly, SGK1 overexpression significantly promoted xenograft tumor growth. Moreover, simultaneous inhibition of SGK1 and Bruton tyrosine kinase (BTK) resulted in synergistic anti-tumor effects on MCL both in vitro and in vivo.

CONCLUSION

SGK1 may be a novel candidate therapeutic target and simultaneous inhibition of SGK1 and BTK may be a promising therapeutic strategy for MCL patients. Further pre-clinical and even clinical studies of SGK1 inhibitor or combination with BTK inhibitor are essential.

Serum and glucocorticoid-regulated kinase 1: Structure, biological functions, and its inhibitors

Serum and glucocorticoid-regulated kinase 1 (SGK1) is a serine/threonine kinase belonging to the protein kinase A, G, and C (AGC) family. Upon initiation of the phosphoinositide 3-kinase (PI3K) signaling pathway, mammalian target of rapamycin complex 2 (mTORC2) and phosphoinositide-dependent protein kinase 1 (PDK1) phosphorylate the hydrophobic motif and kinase domain of SGK1, respectively, inducing SGK1 activation. SGK1 modulates essential cellular processes such as proliferation, survival, and apoptosis. Hence, dysregulated SGK1 expression can result in multiple diseases, including hypertension, cancer, autoimmunity, and neurodegenerative disorders. This review provides a current understanding of SGK1, particularly in sodium transport, cancer progression, and autoimmunity. In addition, we summarize the developmental status of SGK1 inhibitors, their structures, and respective potencies evaluated in pre-clinical experimental settings. Collectively, this review highlights the significance of SGK1 and proposes SGK1 inhibitors as potential drugs for treatment of clinically relevant diseases.

Short-Chain Fatty Acids Reduce Oligodendrocyte Precursor Cells Loss by Inhibiting the Activation of Astrocytes via the SGK1/IL-6 Signalling Pathway

Short-chain fatty acids (SCFAs) are known to be actively involved in neurological diseases, but their roles in hypoxic-ischaemic brain injury (HIBI) are unclear. In this study, a rat model of HIBI was established, and this study measured the changes in IL-6 and NOD-like receptor thermal protein domain associated protein 3 (NLRP3), in addition to proliferation and apoptosis indicators of oligodendrocyte precursor cells (OPCs). The mechanism of action of SCFA on astrocytes was also investigated. Astrocytes were subjected to hypoxia in vitro, and OPCs were treated with IL-6. The results showed that SCFAs significantly alleviated HIBI-induced activation of astrocytes and loss of OPCs. SCFA pretreatment (1) downregulated the expression of NLRP3, IL-6, CCL2, and IP-10; (2) had no effect on the proliferation of OPCs; (3) ameliorated the abnormal expression of Bax and Bcl-2; and (4) regulated IL-6 expression via the SGK1-related pathway in astrocytes. Our findings revealed that SCFAs alleviated the loss of OPCs by regulating astrocyte activation through the SGK1/IL-6 signalling pathway.

Is the glucocorticoid receptor a key player in prostate cancer?: A literature review

Glucocorticoids act through the glucocorticoid receptor (GR) and exert pleiotropic effects in different cancer types. In prostate cancer cells, GR and androgen receptor (AR) share overlapping transcriptomes and cistromes. Under enzalutamide treatment, GR signaling can bypass AR activation and promote castration resistance via the expression of a subset of AR-target genes. However, GR-dependent growth under enhanced antiandrogen inhibition occurs only in a subset of primed cells. On the other hand, glucocorticoids have been used successfully in the treatment of prostate cancer for many years. In the context of AR signaling, GR competes with AR for DNA-binding and has the potential to halt the proliferation rate of prostate cancer cells. Their target genes overlap by <50% and they execute unique functions in vivo. In addition, even when AR and GR upregulate the same transcriptional target gene, the effect might not be identical in magnitude. Besides being able to drive tumor proliferation, GR is also a key player in prostate cancer cell survival. Stimulation of GR activity can undermine the effects of enhanced antiandrogen treatment, chemotherapy and radiotherapy. GR activation in prostate cancer can increase prosurvival gene expression. Identifying the full spectrum of GR activity will inform the optimal use of glucocorticosteroids in prostate cancer. It will also determine the best strategies to target the protumorigenic effects of GR.

Emerging Proteins in CRPC: Functional Roles and Clinical Implications

Prostate cancer (PCa) is the most common cancer in men in the western world, but the lack of specific and sensitive markers often leads to overtreatment of prostate cancer which eventually develops into castration-resistant prostate cancer (CRPC). Novel protein markers for diagnosis and management of CRPC will be promising. In this review, we systematically summarize and discuss the expression pattern of emerging proteins in tissue, cell lines, and serum when castration-sensitive prostate cancer (CSPC) progresses to CRPC; focus on the proteins involved in CRPC growth, invasion, metastasis, metabolism, and immune microenvironment; summarize the current understanding of the regulatory mechanisms of emerging proteins in CSPC progressed to CRPC at the molecular level; and finally summarize the clinical applications of emerging proteins as diagnostic marker, prognostic marker, predictive marker, and therapeutic marker.

Roles of Micro Ribonucleic Acids in Astrocytes After Cerebral Stroke

Cerebral stroke is one of the highest-ranking causes of death and the leading cause of disability globally, particularly with an increasing incidence and prevalence in developing countries. Steadily more evidence has indicated that micro ribonucleic acids (miRNAs) have important regulatory functions in gene transcription and translation in the course of cerebral stroke. It is beyond arduous to understand the pathophysiology of cerebral stroke, due in part to the perplexity of influencing the network of the inflammatory response, brain edema, autophagy and neuronal apoptosis. The recent research shows miRNA plays a key role in regulating aquaporin 4 (AQP4), and many essential pathological processes after cerebral stroke. This article reviews the recent knowledge on how miRNA influences the inflammatory response, brain edema, infarction size, and neuronal injury after cerebral stroke. In addition, some miRNAs may serve as potential biomarkers in stroke diagnosis and therapy since the expression of some miRNAs in the blood is stable after cerebral stroke.

IFI35 Promotes Renal Cancer Progression by Inhibiting pSTAT1/pSTAT6-Dependent Autophagy

Interferon-induced protein 35 (IFI35), is currently acknowledged to govern the virus-related immune inflammatory responses. However, the biological significance and function of IFI35 in renal cell cancer (RCC) is still not well understood. Here, IFI35 expression and function were investigated in RCC tissues, renal cancer cells, and animal models. The results showed that IFI35 expression was significantly increased in 200 specimens of RCC patients. We found that higher IFI35 levels were significantly correlated with poor RCC prognosis. In human cell lines, the knockdown of IFI35 suppressed the malignant behavior of renal cancer cells. Similarly, the IFI35 knockdown resulted in significant inhibition of tumor progression in the subcutaneous or lung metastasis mouse model. Furthermore, the knockdown of IFI35 promoted the induction of autophagy by enhancing the autophagy-related gene expression (LC3-II, Beclin-1, and ATG-5). Additionally, blockade of STAT1/STAT6 phosphorylation (pSTAT1/pSTAT6) abrogated the induced autophagy by IFI35 knockdown in renal cancer cells. The autophagy inhibitor 3-MA also abolished the prevention of tumor growth by deleting IFI35 in renal cancer models. The above results suggest that the knockdown of IFI35 suppressed tumor progression of renal cancer by pSTAT1/pSTAT6-dependent autophagy. Our research revealed that IFI35 may serve as a potential diagnosis and therapeutic target for RCC.

SGK1, a Critical Regulator of Immune Modulation and Fibrosis and a Potential Therapeutic Target in Chronic Graft-Versus-Host Disease

Patients with severe chronic graft-versus-host disease (cGVHD) always experience debilitating tissue injury and have poorer quality of life and shorter survival time. The early stage of cGVHD is characterized by inflammation, which eventually leads to extensive tissue fibrosis in various organs, such as skin and lung, eventually inducing scleroderma-like changes and bronchiolitis obliterans syndrome. Here we review the functions of serum/glucocorticoid regulated kinase 1 (SGK1), a hub molecule in multiple signal transduction pathways and cell phosphorylation cascades, which has important roles in cell proliferation and ion channel regulation, and its relevance in cGVHD. SGK1 phosphorylates the ubiquitin ligase, NEDD4, and induces Th cells to differentiate into Th17 and Th2 phenotypes, hinders Treg development, and promotes inflammatory fibrosis. Phosphorylation of NEDD4 by SGK1 also leads to up-regulation of the transcription factor SMAD2/3, thereby amplifying the fibrosis-promoting effect of TGF-β. SGK1 also up-regulates the inflammatory transcription factor, nuclear factor-κB (NF-κB), which in turn stimulates the expression of multiple inflammatory mediators, including connective tissue growth factor. Overexpression of SGK1 has been observed in various fibrotic diseases, including pulmonary fibrosis, diabetic renal fibrosis, liver cirrhosis, hypertensive cardiac fibrosis, peritoneal fibrosis, and Crohn’s disease. In addition, SGK1 inhibitors can attenuate, or even reverse, the effect of fibrosis, and may be used to treat inflammatory conditions and/or fibrotic diseases, such as cGVHD, in the future.

Targeting autophagy in prostate cancer: preclinical and clinical evidence for therapeutic response

Prostate cancer is a leading cause of death worldwide and new estimates revealed prostate cancer as the leading cause of death in men in 2021. Therefore, new strategies are pertinent in the treatment of this malignant disease. Macroautophagy/autophagy is a “self-degradation” mechanism capable of facilitating the turnover of long-lived and toxic macromolecules and organelles. Recently, attention has been drawn towards the role of autophagy in cancer and how its modulation provides effective cancer therapy. In the present review, we provide a mechanistic discussion of autophagy in prostate cancer. Autophagy can promote/inhibit proliferation and survival of prostate cancer cells. Besides, metastasis of prostate cancer cells is affected (via induction and inhibition) by autophagy. Autophagy can affect the response of prostate cancer cells to therapy such as chemotherapy and radiotherapy, given the close association between autophagy and apoptosis. Increasing evidence has demonstrated that upstream mediators such as AMPK, non-coding RNAs, KLF5, MTOR and others regulate autophagy in prostate cancer. Anti-tumor compounds, for instance phytochemicals, dually inhibit or induce autophagy in prostate cancer therapy. For improving prostate cancer therapy, nanotherapeutics such as chitosan nanoparticles have been developed. With respect to the context-dependent role of autophagy in prostate cancer, genetic tools such as siRNA and CRISPR-Cas9 can be utilized for targeting autophagic genes. Finally, these findings can be translated into preclinical and clinical studies to improve survival and prognosis of prostate cancer patients.

• Prostate cancer is among the leading causes of death in men where targeting autophagy is of importance in treatment;

• Autophagy governs proliferation and metastasis capacity of prostate cancer cells;

• Autophagy modulation is of interest in improving the therapeutic response of prostate cancer cells;

• Molecular pathways, especially involving non-coding RNAs, regulate autophagy in prostate cancer;

• Autophagy possesses both diagnostic and prognostic roles in prostate cancer, with promises for clinical application.

Cordyceps cicadae Ameliorates Renal Hypertensive Injury and Fibrosis Through the Regulation of SIRT1-Mediated Autophagy

Hypertensive renal injury is a complication of hypertension. Cordyceps cicadae (C. cicadae) is a traditional Chinese medicine used to treat chronic kidney diseases especially renal fibrosis. Autophagy is described as a cell self-renewal process that requires lysosomal degradation and is utilized for the maintenance of cellular energy homeostasis. The present study explores the mechanism underlying C. cicadae’s renoprotection on hypertensive nephropathy (HN). First, HN rat models were established on spontaneously hypertensive rats (SHRs). The expression of fibrosis-related protein and autophagy-associated protein was detected in vivo. NRK-52E cells exposed to AngII were chosen to observe the potential health benefits of C. cicadae on renal damage. The level of extracellular matrix accumulation was detected using capillary electrophoresis immunoquantification and immunohistochemistry. After treatment with lysosomal inhibitors (chloroquine) or an autophagy activator (rapamycin), the expression of Beclin-1, LC3II, and SQSTM1/p62 was further investigated. The study also investigated the change in sirtuin1 (SIRT1), fork head box O3a (FOXO3a), and peroxidation (superoxide dismutase (SOD) and malondialdehyde (MDA)) expression when intervened by resveratrol. The changes in SIRT1 and FOXO3a were measured in patients and the SHRs. Here, we observed that C. cicadae significantly decreased damage to renal tubular epithelial cells and TGFβ1, α-smooth muscle actin (α-SMA), collagen I (Col-1), and fibronectin expression. Meanwhile, autophagy defects were observed both in vivo and in vitro. C. cicadae intervention significantly downregulated Beclin-1 and LC3II and decreased SQSTM1/p62, showing an inhibition of autophagic vesicles and the alleviation of autophagy stress. These functions were suppressed by rapamycin, and the results were just as effective as the resveratrol treatment. HN patients and the SHRs exhibited decreased levels of SIRT1 and FOXO3a. We also observed a positive correlation between SIRT1/FOXO3a and antifibrotic effects. Similar to the resveratrol group, the expression of SIRT1/FOXO3a and oxidative stress were elevated by C. cicadae in vivo. Taken together, our findings show that C. cicadae ameliorates tubulointerstitial fibrosis and delays HN progression. Renoprotection was likely attributable to the regulation of autophagic stress mediated by the SIRT1 pathway and achieved by regulating FOXO3a and oxidative stress.

Columbianetin alleviates lipopolysaccharides (LPS)-induced inflammation and apoptosis in chondrocyte through activation of autophagy by inhibiting serum and glucocorticoid-induced protein kinase 1 (SGK1) expression

Osteoarthritis (OA) is a degenerative disease of articular cartilage involving the entire joint tissue. Columbianetin (CBT) is a major active compound of radix angelicae pubescentis, which is used in the treatment of OA. This paper attempts to explore the role of CBT in OA. Lipopolysaccharides (LPS) was used to induce mouse chondrocytes ATDC5. The effect of CBT on cell viability in ATDC5 cells with or without LPS induction was determined by CCK-8 and LDH kits. The inflammatory response was evaluated using ELISA kits. Apoptosis in LPS-induced ATDC5 cells were examined by TUNEL staining. The expression of apoptosis and autophagy-related proteins was tested with Western blot. The relationship between CBT and serum and glucocorticoid-induced protein kinase 1 (SGK1) was examined by RT-qPCR, Western blot, and molecular docking. After SGK1 overexpression or addition of the autophagy inhibitor 3-methyladenine (3 MA), the above experiments were done again. Results revealed that CBT increased LPS-induced decrease in ATDC5 cell viability. CBT inhibited inflammation triggered by LPS, evidenced by reduced levels of TNF-α, IL-6 and IL-1β. Cell apoptosis was attenuated following CBT adding in ATDC5 cells exposed to LPS, accompanied by upregulated Bcl-2 expression and downregulated Bax and cleaved caspase 3 expression. In addition, CBT elevated Beclin1 and LC3II/LC3I expression but decreased p62 expression. Additionally, CBT inhibited SGK1 expression. However, SGK1 overexpression or 3 MA reversed the effects of CBT on LPS-induced loss of ATDC5 cell viability, inflammation, apoptosis and autophagy. Collectively, CBT could improve OA through the activation of chondrocyte autophagy by suppressing SGK1 expression.

SGK1 mutation status can further stratify patients with germinal center B-cell-like diffuse large B-cell lymphoma into different prognostic subgroups

There are over a 100 driver gene mutations in patients with diffuse large B‐cell lymphoma (DLBCL), but their clinical significance remains unclear. Here, we first analyzed the DLBCL dataset from the UK‐based Haematological Malignancy Research Network. Patients were divided into high‐ and low‐risk groups based on whether lymphoma progressed within 24 months. Genes showing significantly different frequencies between groups were selected. Survival data for patients with the selected mutant genes were analyzed. The results were validated using two other large databases to evaluate the relationship between the selected mutant genes and prognosis. The mutation frequencies of 11 genes (MYD88[L265P], SGK1, MPEG1, TP53, SPEN, NOTCH1, ETV6, TNFRSF14, MGA, CIITA, and PIM1) significantly differed between the high‐ and low‐risk groups. The relationships between these mutant genes and patient survival were analyzed. Patients who harbored SGK1 (serum and glucocorticoid‐inducible kinase 1) mutations exhibited the best prognosis. Most patients with SGK1 mutation are germinal center B‐cell (GCB) subtype. Among patients with GCB DLBCL, those harboring SGK1 mutations exhibited better prognosis than those without SGK1 mutations. Most SGK1 mutations were single‐base substitutions, primarily scattered throughout the catalytic domain‐encoding region. Multiple SGK1 mutations were identified in a single patient. Thus, SGK1 mutations are a marker of good prognosis for DLBCL and occur predominantly in the GCB subtype of DLBCL. SGK1 mutation status can further stratify patients with GCB DLBCL into different prognostic subgroups.

E2F transcription factor 2-activated DLEU2 contributes to prostate tumorigenesis by upregulating serum and glucocorticoid-induced protein kinase 1

Long noncoding RNAs (lncRNAs) participate in biological processes in multiple types of tumors. However, the regulatory patterns of lncRNAs in prostate cancer remain largely unclear. Here, we evaluated the expression and roles of the lncRNA DLEU2 in prostate cancer. Our results showed that DLEU2 was upregulated in advanced prostate cancer tissues. Patients with prostate cancer displaying high expression of DLEU2 had a poor prognosis. Moreover, we demonstrated that overexpression of DLEU2 facilitated the proliferation, migration, and invasion of prostate cancer in vitro. Mechanistically, DLEU2 promoted serum and glucocorticoid-induced protein kinase 1 (SGK1) expression by acting as an miR-582-5p sponge, and the transcription of DLEU2 was activated by the dysregulation of E2F transcription factor 2 (E2F2) expression in prostate cancer. Furthermore, knockdown of DLEU2 attenuated prostate cancer tumorigenesis in vivo. Notably, these findings suggested that E2F2-activated DLEU2 may function as a competing endogenous RNA to facilitate prostate cancer progression by targeting the miR-582-5p/SGK1 axis.

Cyclophosphamide affects eye development and locomotion in zebrafish (Danio rerio)

Cyclophosphamide (CP) is a broad-spectrum anticancer drug and has been frequently detected in aquatic environments due to its incomplete removal by wastewater treatment facilities and slow degradation in waters. Its toxicity in fish remains largely unknown. In this study, zebrafish eggs <4 h post fertilization (hpf) were exposed to CP at the concentrations from 0.5 to 50.0 μg/L until 168 hpf, and its toxicity was evaluated by biochemical, transcriptomic, and behavioral approaches. The results showed that malformation and mortality rates increased with CP concentrations. The 7-day malformation EC₅₀ and mortality (LC₃₀) by CP were calculated to be 86.8 μg/L and 7.5 mg/L, respectively. Inhibited startle response (light to dark) (a minimal of 19%) and reduced swimming velocity (a minimal of 30%) were observed in the CP-exposed larvae. The thicknesses of retinal ganglion layer, inner plexiform layer, and inner nuclear layer in the retina were increased after exposure to CP. Meanwhile, exposure to CP increased karyorrhexis and karyolysis in the liver tissue. Transcriptomic analysis identified 607 differentially expressed genes (DEGs) (159 up-regulated and 448 down-regulated). A significant reduction in the transcripts of sgk1 (the FoxO pathway), jun (the MAPK pathway), and diabloa (apoptosis pathway) were observed in the CP-treated larvae. This study has demonstrated that low concentrations of CP cause malformation, reduced swimming capacity, histopathological alterations in the retina and liver tissues, and interference on transcriptional expressions of key genes associated with different pathways. The ecological risk of CP and other anticancer drugs to aquatic organisms merits future investigation.

Deglycosylated EpCAM regulates proliferation by enhancing autophagy of breast cancer cells via PI3K/Akt/mTOR pathway

Autophagy is an important regulator of cellular homeostasis and its dysregulation often results in cancer. Aberrant glycosylation induced by oncogenic transformation contributes to tumor invasion and metastasis. In a previous study, we have demonstrated that EpCAM, a glycosylation protein, is associated with cell growth and metastasis in breast cancer. But the effect of EpCAM glycosylation on autophagy is not clear. the precise mechanism of regulation remains largely unknown. In this study, breast cancer cells were transfected with N-glycosylation mutation EpCAM plasmid to express deglycosylated EpCAM. The result showed that deglycosylated EpCAM promoted autophagy in breast cancer cells. We further confirmed this conclusion with the activator (Rapamycin, RAP) and inhibitor (Wortmannin) of autophagy. We also found that deglycosylated EpCAM promoted apoptosis and inhibited proliferation through activating autophagy by suppressing Akt/mTOR signaling pathway in breast cancer cells. These findings represent a novel mechanism by which deglycosylated EpCAM inhibits proliferation by enhancing autophagy of breast cancer cells via PI3K/Akt/mTOR pathway. In conclusion, the combination of autophagy modulation and EpCAM targeted therapy is a promising therapeutic strategy in the treatment of breast cancer.

Discovery of a novel Aurora B inhibitor GSK650394 with potent anticancer and anti-aspergillus fumigatus dual efficacies in vitro

Invasive fungal infections including Candidiasis and Aspergillosis are associated with considerable morbidity and mortality in immunocompromised individuals, such as cancer patients. Aurora B is a key mitotic kinase required for the cell division of eukaryotes from fungus to man. Here, we identified a novel Aurora B inhibitor GSK650394 that can inhibit the recombinant Aurora B from human and Aspergillus fumigatus, with IC₅₀ values of 5.68 and 1.29 µM, respectively. In HeLa and HepG2 cells, GSK650394 diminishes the endogenous Aurora B activity and causes cell cycle arrest in G2/M phase. Further cell-based assays demonstrate that GSK650394 efficiently suppresses the proliferation of both cancer cells and Aspergillus fumigatus. Finally, the molecular docking calculation and site-directed mutagenesis analyses reveal the molecular mechanism of Aurora B inhibition by GSK650394. Our work is expected to provide new insight into the combinational therapy of cancer and Aspergillus fumigatus infection.

Caffeine Induces Autophagy and Apoptosis in Auditory Hair Cells via the SGK1/HIF-1α Pathway

Caffeine is being increasingly used in daily life, such as in drinks, cosmetics, and medicine. Caffeine is known as a mild stimulant of the central nervous system, which is also closely related to neurologic disease. However, it is unknown whether caffeine causes hearing loss, and there is great interest in determining the effect of caffeine in cochlear hair cells. First, we explored the difference in auditory brainstem response (ABR), organ of Corti, stria vascularis, and spiral ganglion neurons between the control and caffeine-treated groups of C57BL/6 mice. RNA sequencing was conducted to profile mRNA expression differences in the cochlea of control and caffeine-treated mice. A CCK-8 assay was used to evaluate the approximate concentration of caffeine. Flow cytometry, TUNEL assay, immunocytochemistry, qRT-PCR, and Western blotting were performed to detect the effects of SGK1 in HEI-OC1 cells and basilar membranes. In vivo research showed that 120 mg/ kg caffeine injection caused hearing loss by damaging the organ of Corti, stria vascularis, and spiral ganglion neurons. RNA-seq results suggested that SGK1 might play a vital role in ototoxicity. To confirm our observations in vitro, we used the HEI-OC1 cell line, a cochlear hair cell-like cell line, to investigate the role of caffeine in hearing loss. The results of flow cytometry, TUNEL assay, immunocytochemistry, qRT-PCR, and Western blotting showed that caffeine caused autophagy and apoptosis via SGK1 pathway. We verified the interaction between SGK1 and HIF-1α by co-IP. To confirm the role of SGK1 and HIF-1α, GSK650394 was used as an inhibitor of SGK1 and CoCl₂ was used as an inducer of HIF-1α. Western blot analysis suggested that GSK650394 and CoCl₂ relieved the caffeine-induced apoptosis and autophagy. Together, these results indicated that caffeine induces autophagy and apoptosis in auditory hair cells via the SGK1/HIF-1α pathway, suggesting that caffeine may cause hearing loss. Additionally, our findings provided new insights into ototoxic drugs, demonstrating that SGK1 and its downstream pathways may be potential therapeutic targets for hearing research at the molecular level.

Curcumin and Carnosic Acid Cooperate to Inhibit Proliferation and Alter Mitochondrial Function of Metastatic Prostate Cancer Cells

Anticancer activities of plant polyphenols have been demonstrated in various models of neoplasia. However, evidence obtained in numerous in vitro studies indicates that proliferation arrest and/or killing of cancer cells require quite high micromolar concentrations of polyphenols that are difficult to reach in vivo and can also be (geno)toxic to at least some types of normal cells. The ability of certain polyphenols to synergize with one another at low concentrations can be used as a promising strategy to effectively treat human malignancies. We have recently reported that curcumin and carnosic acid applied at non-cytotoxic concentrations synergistically cooperate to induce massive apoptosis in acute myeloid leukemia cells, but not in normal hematopoietic and non-hematopoietic cells, via sustained cytosolic calcium overload. Here, we show that the two polyphenols can also synergistically suppress the growth of DU145 and PC-3 metastatic prostate cancer cell cultures. However, instead of cell killing, the combined treatment induced a marked inhibition of cell proliferation associated with G₀/G₁ cell cycle arrest. This was preceded by transient elevation of cytosolic calcium levels and prolonged dissipation of the mitochondrial membrane potential, without generating oxidative stress, and was associated with defective oxidative phosphorylation encompassing mitochondrial dysfunction. The above effects were concomitant with a significant downregulation of mRNA and protein expression of the oncogenic kinase SGK1, the mitochondria-hosted mTOR component. In addition, a moderate decrease in SGK1 phosphorylation at Ser422 was observed in polyphenol-treated cells. The mTOR inhibitor rapamycin produced a similar reduction in SGK1 mRNA and protein levels as well as phosphorylation. Collectively, our findings suggest that the combination of curcumin and carnosic acid at potentially bioavailable concentrations may effectively target different types of cancer cells by distinct modes of action. This and similar combinations merit further exploration as an anticancer modality.

Liquiritigenin exerts the anti-cancer role in oral cancer via inducing autophagy-related apoptosis through PI3K/AKT/mTOR pathway inhibition in vitro and in vivo

Operative treatment on oral cancer greatly damages the chewing and language function of the patient, we aim to find better solution with fewer side effects. The anti-tumor effects of Liquiritigenin (LQ) have been explored in kinds of cancers, but not in oral cancer. In this study, our purpose is to reveal the effects of LQ on oral cancer and the associated mechanism.Cell proliferation was examined through 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 5-Ethynyl-2'- deoxyuridine (EDU) staining. Cell apoptosis in cells and tissues were assessed by flow cytometry and terminal dexynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, respectively. Expressions of AKT and light chain 3 (LC3) were detected through Immunofluorescence. In addition, xenograft model was established by injecting the CAL-27 cells (2 × 10⁶) subcutaneously into the right flanks of mice. Expression of Ki67 and Beclin1 in tissues was valued by Immunohistochemistry (IHC).We found that cell viability of CAL-27 and SCC-9 was effectively inhibited by LQ. Besides, obvious cell apoptosis and cell autophagy were induced by LQ. In addition, PI3K/AKT/mTOR pathway was sharply inactivated by LQ in oral cancer cells. Corresponding in vivo experiments demonstrated that tumor growth was largely restricted, cell apoptosis was augmented and autophagy was enhanced by LQ. What is more, phosphorylation of AKT in tumor tissues could also be inhibited by LQ. LQ inhibited the progression of oral cancer through inducing autophagy-associated apoptosis via PI3K/AKT/mTOR pathway inhibition, revealing a new possible scheme for the treatment of oral cancer.

mTORC2: The other mTOR in autophagy regulation

The mechanistic target of rapamycin (mTOR) has gathered significant attention as a ubiquitously expressed multimeric kinase with key implications for cell growth, proliferation, and survival. This kinase forms the central core of two distinct complexes, mTORC1 and mTORC2, which share the ability of integrating environmental, nutritional, and hormonal cues but which regulate separate molecular pathways that result in different cellular responses. Particularly, mTORC1 has been described as a major negative regulator of endosomal biogenesis and autophagy, a catabolic process that degrades intracellular components and organelles within the lysosomes and is thought to play a key role in human health and disease. In contrast, the role of mTORC2 in the regulation of autophagy has been considerably less studied despite mounting evidence this complex may regulate autophagy in a different and perhaps complementary manner to that of mTORC1. Genetic ablation of unique subunits is currently being utilized to study the differential effects of the two mTOR complexes. RICTOR is the best‐described subunit specific to mTORC2 and as such has become a useful tool for investigating the specific actions of this complex. The development of complex‐specific inhibitors for mTORC2 is also an area of intense interest. Studies to date have demonstrated that mTORC1/2 complexes each signal to a variety of exclusive downstream molecules with distinct biological roles. Pinpointing the particular effects of these downstream effectors is crucial toward the development of novel therapies aimed at accurately modulating autophagy in the context of human aging and disease.

Suppression of phosphoinositide 3-kinase/phosphoinositide-dependent kinase-1/serum and glucocorticoid-induced protein kinase pathway

In the current study, the pivotal roles of serum and glucocorticoid-induced protein kinase (SGK1) and NF-kB related signalings known as prognostic biomarkers in cervical cancers were explored in the antitumor effect of a ginseng saponin metabolite compound K (CK) in HeLa and SiHa cervical cancer cells. CK exerted significant cytotoxicity, induced sub-G1 accumulation, and attenuated the expression of proPoly (ADP-ribose) polymerase (pro-PARP) and Pro-cysteine aspartyl-specific protease (pro-caspase3) in HeLa cells more than in SiHa cells. CK inhibited phosphorylation of SGK1 and its upstream genes, phosphoinositide 3-kinases (PI3K), and phosphoinositide-dependent kinase-1 (PDK1) in HeLa cells. In addition, CK suppressed the phosphorylation of SGK1, NF-κB, and inhibitor of kappa B (IκB) and also NF-κB target genes such as X-linked inhibitor of apoptosis protein and B-cell lymphoma 2 (Bcl-2) in HeLa cells. Notably, Immunoprecipitation revealed that SGK1 binds to PI3K or PDK1 and also CK disturbed the binding between SGK1 and PI3K or PDK1 in HeLa cells. Furthermore, PI3K inhibitor LY294002 decreased expression of PI3K, p-PDK1, p-SGK1, and pro-caspase3 and SGK1 inhibitor GSK650394 also reduced expression of NF-κB and pro-caspase3 just like CK in HeLa cells. Overall, these findings suggest that CK induces apoptosis via suppression of PI3K/PDK1/SGK1 and NF-κB signaling axis.

Demethylzeylasteral Exerts Antitumor Effects via Disruptive Autophagic Flux and Apoptotic Cell Death in Human Colorectal Cancer Cells and Increases Cell Chemosensitivity to 5-Fluorouracil

BACKGROUND

Demethylzeylasteral (ZST93), a pharmacologically active triterpenoid monomer extracted from Tripterygium wilfordii Hook F (TWHF), has been reported to exert antineoplastic effects in several cancer cell types. However, the anti-tumour effects of ZST93 in human colorectal cancer (CRC) cells are unknown.

OBJECTIVE

The aim of the present study was to evaluate the antitumor effects of ZST93 on cell cycle arrest, disruptive autophagic flux, apoptotic cell death, and enhanced chemosensitivity to 5-FU in humans CRC cells.

METHODS

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) assay, colony formation assay, flow cytometry, immunoblotting, immunofluorescence, 5-ethynyl-20-deoxyuridine (EdU) incorporation assay, and autophagy analysis were used to evaluate the effects of ZST93 on cell viability, cell cycle progression, apoptosis and autophagy in two human CRC cell lines. Moreover, ZST93's combined anti-tumour effects with 5-fluorouracil (5-FU) were evaluated.

RESULTS

ZST93 inhibited CRC cell proliferation and growth. It was responsible for blocked cell cycle transition by arresting CRC cells in the G0/G1 phase via down-regulation of CDK4, CDK6, Cyclin D1, and c-MYC. Moreover, ZST93 induced suppressive autophagic flux and caspase-3-dependent cell death, which were further strengthened by the blocking of the autophagy process using chloroquine (CQ). Moreover, ZST93 enhanced CRC cells' chemosensitivity to 5-FU via modulation of autophagy and apoptosis.

CONCLUSION

ZST93 exerts anti-tumour effects via disruptive autophagic flux and apoptotic cell death in human CRC cells and increases cell chemosensitivity to 5-FU. These results provide insights into the utilisation of ZST93 as an adjuvant or direct autophagy inhibitor and suggest ZST93 as a novel therapeutic strategy for treating CRC.

Combination of Metformin, Sodium Oxamate and Doxorubicin Induces Apoptosis and Autophagy in Colorectal Cancer Cells via Downregulation HIF-1α

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide in both sexes. Current therapies include surgery, chemotherapy, and targeted therapy; however, prolonged exposure to chemical agents induces toxicity in patients and drug resistance. So, we implemented a therapeutic strategy based on the combination of doxorubicin, metformin, and sodium oxamate called triple therapy (Tt). We found that Tt significantly reduced proliferation by inhibiting the mTOR/AKT pathway and promoted apoptosis and autophagy in CRC derived cells compared with doxorubicin. Several autophagy genes were assessed by western blot; ULK1, ATG4, and LC3 II were overexpressed by Tt. Interestingly, ULK1 was the only one autophagy-related protein gradually overexpressed during Tt administration. Thus, we assumed that there was a post-transcriptional mechanism mediating by microRNAs that regulate UKL1 expression during autophagy activation. Through bioinformatics approaches, we ascertained that ULK1 could be targeted by mir-26a, which is overexpressed in advanced stages of CRC. In vitro experiments revealed that overexpression of mir-26a decreased significantly ULK1, mRNA, and protein expression. Contrariwise, the Tt recovered ULK1 expression by mir-26a decrease. Due to triple therapy repressed mir-26a expression, we hypothesized this drug combination could be involved in mir-26a transcription regulation. Consequently, we analyzed the mir-26a promoter sequence and found two HIF-1α transcription factor recognition sites. We developed two different HIF-1α stabilization models. Both showed mir-26a overexpression and ULK1 reduction in hypoxic conditions. Immunoprecipitation experiments were performed and HIF-1α enrichment was observed in mir-26a promoter. Surprisingly, Tt diminished HIF-1α detection and restored ULK1 mRNA expression. These results reveal an important regulation mechanism controlled by the signaling that activates HIF-1α and that in turn regulates mir-26a transcription.

Emerging roles and mechanisms of microRNA‑222‑3p in human cancer (Review)

MicroRNAs (miRNAs/miRs) are a class of small non‑coding RNAs that maintain the precise balance of various physiological processes through regulating the function of target mRNAs. Dysregulation of miRNAs is closely associated with various types of human cancer. miR‑222‑3p is considered a canonical factor affecting the expression and signal transduction of multiple genes involved in tumor occurrence and progression. miR‑222‑3p in human biofluids, such as urine and plasma, may be a potential biomarker for the early diagnosis of tumors. In addition, miR‑222‑3p acts as a prognostic factor for the survival of patients with cancer. The present review first summarizes and discusses the role of miR‑222‑3p as a biomarker for diverse types of cancers, and then focuses on its essential roles in tumorigenesis, progression, metastasis and chemoresistance. Finally, the current understanding of the regulatory mechanisms of miR‑222‑3p at the molecular level are summarized. Overall, the current evidence highlights the crucial role of miR‑222‑3p in cancer diagnosis, prognosis and treatment.

Baicalein attenuates cardiac hypertrophy in mice via suppressing oxidative stress and activating autophagy in cardiomyocytes

Baicalein is a natural flavonoid extracted from the root of Scutellaria baicalensis that exhibits a variety of pharmacological activities. In this study, we investigated the molecular mechanisms underlying the protective effect of baicalein against cardiac hypertrophy in vivo and in vitro. Cardiac hypertrophy was induced in mice by injection of isoproterenol (ISO, 30 mg·kg-1·d-1) for 15 days. The mice received caudal vein injection of baicalein (25 mg/kg) on 3rd, 6th, 9th, 12th, and 15th days. We showed that baicalein administration significantly attenuated ISO-induced cardiac hypertrophy and restored cardiac function. The protective effect of baicalein against cardiac hypertrophy was also observed in neonatal rat cardiomyocytes treated with ISO (10 μM). In cardiomyocytes, ISO treatment markedly increased reactive oxygen species (ROS) and inhibited autophagy, which were greatly alleviated by pretreatment with baicalein (30 μM). We found that baicalein pretreatment increased the expression of catalase and the mitophagy receptor FUN14 domain containing 1 (FUNDC1) to clear ROS and promote autophagy, thus attenuated ISO-induced cardiac hypertrophy. Furthermore, we revealed that baicalein bound to the transcription factor FOXO3a directly, promoting its transcription activity, and transactivated catalase and FUNDC1. In summary, our data provide new evidence for baicalein and FOXO3a in the regulation of ISO-induced cardiac hypertrophy. Baicalein has great potential for the treatment of cardiac hypertrophy.

Single-Cell RNA Sequencing Analysis of the Immunometabolic Rewiring and Immunopathogenesis of Coronavirus Disease 2019

Although immune dysfunction is a key feature of coronavirus disease 2019 (COVID-19), the metabolism-related mechanisms remain elusive. Here, by reanalyzing single-cell RNA sequencing data, we delineated metabolic remodeling in peripheral blood mononuclear cells (PBMCs) to elucidate the metabolic mechanisms that may lead to the progression of severe COVID-19. After scoring the metabolism-related biological processes and signaling pathways, we found that mono-CD14⁺ cells expressed higher levels of glycolysis-related genes (PKM, LDHA and PKM) and PPP-related genes (PGD and TKT) in severe patients than in mild patients. These genes may contribute to the hyperinflammation in mono-CD14⁺ cells of patients with severe COVID-19. The mono-CD16⁺ cell population in COVID-19 patients showed reduced transcription levels of genes related to lysine degradation (NSD1, KMT2E, and SETD2) and elevated transcription levels of genes involved in OXPHOS (ATP6V1B2, ATP5A1, ATP5E, and ATP5B), which may inhibit M2-like polarization. Plasma cells also expressed higher levels of the OXPHOS gene ATP13A3 in COVID-19 patients, which was positively associated with antibody secretion and survival of PCs. Moreover, enhanced glycolysis or OXPHOS was positively associated with the differentiation of memory B cells into plasmablasts or plasma cells. This study comprehensively investigated the metabolic features of peripheral immune cells and revealed that metabolic changes exacerbated inflammation in monocytes and promoted antibody secretion and cell survival in PCs in COVID-19 patients, especially those with severe disease.

Knockdown of SLC39A4 Expression Inhibits the Proliferation and Motility of Gallbladder Cancer Cells and Tumor Formation in Nude Mice

Purpose

Gallbladder cancer (GBC) is a common malignancy of the biliary tract and is characterized by rapid progression and early metastasis. Elucidating the molecular mechanisms of GBC could help to develop better treatment strategies.

Materials and Methods

Human GBC cell lines (GBC-SD and NOZ) were applied to determine the capacity of the proliferation and migration of cells using the MTT assay, colony formation, wound-healing assay as well as the Transwell™ assay. A nude xenograft was used to evaluate tumor growth in vivo.

Results

Using two types of GBC cell lines, we found that absence of solute carrier family (SLC) 39A4 (which encodes the zinc transporter ZRT/IRT-like protein [ZIP]4), could suppress the proliferation and migration of cells. Additionally, absence of ZIP4 could impair growth of xenografts in nude mice. While, over-expression of SLC39A4 could promote the GBC cell proliferation and migration, and inhibit apoptosis. We revealed that SLC39A4 might affect GBC progression by modulating the signaling pathways responsible for the survival, energy supply and metastasis of cells, and indicated that SLC39A4 could serve as a novel therapeutic target for GBC.

Conclusion

SLC39A4 promoted the viability and motility of GBC cells, and tumor formation in nude mice. We demonstrated an oncogenic potential for SLC39A4.

Cutaneous and hepatic vascular lesions due to a recurrent somatic GJA4 mutation reveal a pathway for vascular malformation

The term “cavernous hemangioma” has been used to describe vascular anomalies with histology featuring dilated vascular spaces, vessel walls consisting mainly of fibrous stromal bands lined by a layer of flattened endothelial cells, and an irregular outer rim of interrupted smooth muscle cells. Hepatic hemangiomas (HHs) and cutaneous venous malformations (VMs) share this histologic pattern, and we examined lesions in both tissues to identify genetic drivers. Paired whole-exome sequencing (WES) of lesional tissue and normal liver in HH subjects revealed a recurrent GJA4 c.121G>T (p.Gly41Cys) somatic mutation in four of five unrelated individuals, and targeted sequencing in paired tissue from 9 additional HH individuals identified the same mutation in 8. In cutaneous lesions, paired targeted sequencing in 5 VMs and normal epidermis found the same GJA4 c.121G>T (p.Gly41Cys) somatic mutation in three. GJA4 encodes gap junction protein alpha 4, also called connexin 37 (Cx37), and the p.Gly41Cys mutation falls within the first transmembrane domain at a residue highly conserved among vertebrates. We interrogated the impact of the Cx37 mutant via lentiviral transduction of primary human endothelial cells. We found that the mutant induced changes in cell morphology and activated serum/glucocorticoid-regulated kinase 1 (SGK1), a serine/threonine kinase known to regulate cell proliferation and apoptosis, via non-canonical activation. Treatment with spironolactone, an inhibitor of angiogenesis, suppressed mutant SGK1 activation and reversed changes in cell morphology. These findings identify a recurrent somatic GJA4 c.121G>T mutation as a driver of hepatic and cutaneous VMs, revealing a new pathway for vascular anomalies, with spironolactone a potential pathogenesis-based therapy.

Antiangiogenic effect of arsenic trioxide in HUVECs by FoxO3a-regulated autophagy

Arsenic trioxide (ATO) has been shown to have antitumor effect in different tumors, although the underlying mechanisms are not fully understood. Autophagy plays a critical role in tumorigenesis and cancer therapy and has been found to be activated by ATO in different cells. However, the role of autophagy in the antitumor effect of ATO has not yet been elucidated. In this study, we investigated the role of autophagy in the antiangiogenic effect of ATO in human umbilical vein endothelial cells (HUVECs) in vitro and its underlying mechanism. Our data showed that ATO suppresses angiogenesis and induces autophagy in HUVECs through upregulation of forkhead box protein O3 (FoxO3a). Co-incubated with autophagy inhibitor or knockdown of FoxO3a effectively inhibited ATO-induced autophagy and reversed the antiangiogenic effect of ATO, indicating that ATO-induced autophagy plays an antiangiogenic role in HUVECs. Our results highlight the importance of autophagy in the antiangiogenic effect of ATO and provide an improved understanding of the function of ATO.

The interaction of TEA domain transcription factor 4 (TEAD4) and Yes-associated protein 1 (YAP1) promoted the malignant process mediated by serum/glucocorticoid regulated kinase 1 (SGK1)

TEA domain transcription factor 4 (TEAD4) has been investigated to be implicated in the progression of various cancers, and it plays a role in the esophageal squamous cell carcinoma (ESCC). The study was designed to investigate how TEAD4 affected the progression of ESCC through Hippo signaling pathway in vitro and in vivo. The interaction of TEAD4 and Yes-associated protein (YAP) was detected though immunoprecipitation assay (IP). Following the treatment of TED-347, which was able to suppress the interaction of TEAD4 and YAP1, the malignant behaviors of cells including proliferation, invasion, and migration were assessed by EDU staining, wound healing, and transwell assay in vitro, while tumor growth was measured. Luciferase reporter plasmids containing the enhancer and promoter region of serum/glucocorticoid regulated kinase 1 (SGK1) were constructed to analyze how TEAD4 affected the transcription of SGK1. The above cell behaviors were further analyzed after the silencing of SGK1. Results showed that TED-347 hindered the promoting effect of TEAD4 overexpression on the malignant behaviors of ESCC cells, and this effect was related to the suppression of the TEAD4/YAP1 complex. Moreover, the promoter activity of SGK1 was obviously inhibited by TED-347. Decreased expression of SGK1 suppressed the above behaviors of cells and destroyed the effects of increased expression of TEAD4. Collectively, TEAD4/YAP promotes the malignant process of ESCC cells, which was inhibited by the interference of SGK1. Targeting TEAD4/YAP1 complex or SGK1 could find application in the treatment of esophageal squamous cell carcinoma.