Autophagy as a cell death and tumor suppressor mechanism

Autophagy induced by metabolic processes leads to solid tumor cell metastatic dormancy and recurrence

A crucial cellular mechanism that has a complex impact on the biology of cancer, particularly in solid tumors, is autophagy. This review explores how metabolic processes trigger autophagy, which helps metastatic tumor cells go dormant and recur. During metastasis, tumor cells frequently encounter severe stressors, such as low oxygen levels and nutritional deprivation, which causes them to activate autophagy as a survival tactic. This process allows cancer stem cells (CSCs) to withstand severe conditions while also preserving their features. After years of dormancy, dormant disseminated tumor cells (DTCs) may reappear as aggressive metastatic cancers. The capacity of autophagy to promote resistance to treatments and avoid immune detection is intimately related to this phenomenon. According to recent research, autophagy promotes processes, such as the epithelial-to-mesenchymal transition (EMT) and helps build a pre-metastatic niche, which makes treatment strategies more challenging. Autophagy may be a promising therapeutic target because of its dual function as a tumor suppressor in early-stage cancer and a survival promoter in advanced stages. To effectively treat metastatic diseases, it is crucial to comprehend how metabolic processes interact with autophagy and affect tumor behavior. In order to find novel therapeutic approaches that can interfere with these processes and improve patient outcomes, this study highlights the critical need for additional investigation into the mechanisms by which autophagy controls tumor dormancy and recurrence.

The interplay between probiotics and host autophagy: mechanisms of action and emerging insights

Autophagy, a lysosome-dependent protein degradation mechanism, is a highly conserved catabolic process seen in all eukaryotes. This cell protection system, which is present in all tissues and functions at a basic level, can be up- or downregulated in response to various stresses. A disruption in the natural route of the autophagy process is frequently followed by an interruption in the inherent operation of the body's cells and organs. Probiotics are live bacteria that protect the host through various mechanisms. One of the processes through which probiotics exert their beneficial effects on various cells and tissues is autophagy. Autophagy can assist in maintaining host homeostasis by stimulating the immune system and affecting numerous physiological and pathological responses. In this review, we particularly focus on autophagy impairments occurring in several human illnesses and investigate how probiotics affect the autophagy process under various circumstances.Abbreviation: AD: Alzheimer disease; AKT: AKT serine/threonine kinase; AMPK: 5'AMP-activated protein kinase; ATG: autophagy related; CCl4: carbon tetrachloride; CFS: cell-free supernatant; CMA: chaperone-mediated autophagy; CRC: colorectal cancer; EPS: L. plantarum H31 exopolysaccharide; HD: Huntington disease; HFD: high-fat diet; HPV: human papillomavirus; IFNG/IFN-γ: interferon gamma; IL6: interleukin 6; LGG: L. rhamnosus GG; LPS: lipopolysaccharide; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; NAFLD: non-alcoholic fatty liver disease; NASH: non-alcoholic steatohepatitis; PD: Parkinson disease; Pg3G: pelargonidin-3-O-glucoside; PI3K: phosphoinositide 3-kinase; PolyQ: polyglutamine; ROS: reactive oxygen species; SCFAs: short-chain fatty acids; SLAB51: a novel formulation of lactic acid bacteria and bifidobacteria; Slp: surface layer protein (of acidophilus NCFM); SNCA: synuclein alpha; ULK1: unc-51 like autophagy-activating kinase 1; YB: B. longum subsp. infantis YB0411; YFP: yeast fermentate prebiotic.

Portrait of WWP1: the current state in human cancer

WWP1, a member of the C2-WW-HECT E3 ligase family, is an E3 ubiquitin-protein ligase containing WW domains. This enzyme plays a critical role in regulating diverse cellular processes. Its expression is modulated by various factors and non-coding RNAs, resulting in ubiquitination that affects substrate protein degradation. WWP1 demonstrates a dual function, acting predominantly as an oncogene in tumors but occasionally as a tumor suppressor. This review summarizes WWP1's biological roles, therapeutic potential in oncology, upstream regulatory factors, and downstream substrates. It aims to promote research on WWP1's antitumor effects, improve understanding of its role in tumorigenesis, and support the development of targeted therapies.

Trehalose enhances macrophage autophagy to promote myelin debris clearance after spinal cord injury

BACKGROUND

Myelin-laden foamy macrophages accumulate extensively in the lesion epicenter, exhibiting characteristics of autophagolysosomal dysfunction, which leads to prolonged inflammatory responses after spinal cord injury (SCI). Trehalose, known for its neuroprotective properties as an autophagy inducer, has yet to be fully explored for its potential to mitigate foamy macrophage formation and exert therapeutic effects in the context of SCI.

RESULTS

We observed that trehalose significantly enhances macrophage phagocytosis and clearance of myelin in a dose-dependent manner in vitro. In vivo, trehalose administration markedly reduced myelin debris accumulation, inhibited foamy macrophage formation, suppressed inflammatory responses, decreased fibrotic scarring, and promoted axonal growth and motor function recovery after SCI. These beneficial effects of trehalose may be related to the overexpression of transcription factor EB (TFEB), a key regulator of the autophagy-lysosomal system, which can rescue autophagic dysfunction in foamy macrophages and inhibit inflammatory responses. Additionally, the effects of trehalose on macrophages were abolished by chloroquine, an autophagy inhibitor, suggesting trehalose's potential as a therapeutic candidate for enhancing myelin debris clearance post-SCI.

CONCLUSIONS

Our findings underscore the pivotal role of trehalose in modulating myelin debris clearance within macrophages, providing new perspectives for the treatment of spinal cord injury.

Beclin-1 and LC3B expression in canine mast cell tumours: an immuno-ultrastructural and immunohistochemical study of autophagy

Mast cell tumours (MCTs) are common malignant neoplasms in dogs, for which prognosis and therapeutic decisions are based on histological features and proliferation markers. Autophagy is a cellular catabolic process responsible for degrading cytoplasmic components to maintain homeostasis, alterations in which are frequently linked to tumour growth and progression. This study was conducted to investigate the occurrence of autophagy in canine MCTs and to verify its value as a prognostic indicator for dogs with the disease. Beclin-1 and LC3B expressions were investigated using immunohistochemistry, and autophagy was ultrastructurally characterised. The autophagic phenomenon was successfully visualised in neoplastic mast cells under transmission electron and immunoelectron microscopy. MCTs from dogs that died due to the disease showed higher positivity for Beclin-1 and dogs with MCTs presenting a LC3B granular immunohistochemical pattern had a significantly shorter post-surgical survival. The occurrence of autophagy is an indicator of poor prognosis. Future studies are needed to elucidate the specific mechanisms and open new opportunities to treatments targeting this cancer cell advantage.

Autophagy in oral cancer: Promises and challenges (Review)

Autophagy captures damaged or dysfunctional proteins and organelles through the lysosomal pathway to achieve proper cellular homeostasis. Autophagy possesses distinct characteristics and is given recognized functions in numerous physiological and pathological conditions, such as cancer. Early stage cancer development can be stopped by autophagy. After tumor cells have successfully undergone transformation and progressed to a late stage, the autophagy-mediated system of dynamic degradation and recycling will support cancer cell growth and adaptation to various cellular stress responses while preserving energy homeostasis. In the present study, the dual function that autophagy plays in various oral cancer development contexts and stages, the existing arguments for and against autophagy, and the ways in which autophagy contributes to oral cancer modifications, such as carcinogenesis, drug resistance, invasion, metastasis and self-proliferation, are reviewed. Special attention is paid to the mechanisms and functions of autophagy in oral cancer processes, and the most recent findings on the application of certain conventional drugs or natural compounds as novel agents that modulate autophagy in oral cancer are discussed. Overall, further research is needed to determine the validity and reliability of autophagy promotion and inhibition while maximizing the difficult challenge of increasing cancer suppression to improve clinical outcomes.

SIRT1 silencing promotes EMT and Crizotinib resistance by regulating autophagy through AMPK/mTOR/S6K signaling pathway in EML4-ALK L1196M and EML4-ALK G1202R mutant non-small cell lung cancer cells

Most EML4-ALK rearrangement non-small cell lung cancer (NSCLC) patients inevitably develop acquired drug resistance after treatment. The main mechanism of drug resistance is the acquired secondary mutation of ALK kinase domain. L1196M and G1202R are classical mutation sites. We urgently need to understand the underlying molecular mechanism of drug resistance to study the therapeutic targets of mutant drug-resistant NSCLC cells. The silent information regulator sirtuin1 (SIRT1) can regulate the normal energy metabolism of cells, but its role in cancer is still unclear. In our report, it was found that the SIRT1 in EML4-ALK G1202R and EML4-ALK L1196M mutant drug-resistant cells was downregulated compared with EML4-ALK NSCLC cells. The high expression of SIRT1 was related to the longer survival time of patients with lung cancer. Activation of SIRT1 induced autophagy and suppressed the invasion and migration of mutant cells. Further experiments indicated that the activation of SIRT1 inhibited the phosphorylation level of mTOR and S6K by upregulating the expression of AMPK, thus activating autophagy. SIRT1 can significantly enhanced the sensitivity of mutant cells to crizotinib, improved its ability to promote apoptosis of mutant cells, and inhibited cell proliferation. In conclusion, SIRT1 is a key regulator of drug resistant in EML4-ALK L1196M and G1202R mutant cells. SIRT1 may be a novel therapeutic target for EML4-ALK drug resistant NSCLC.

Combined sulforaphane and β-sitosterol mitigate olanzapine-induced metabolic disorders in rats: Insights on FOXO, PI3K/AKT, JAK/STAT3, and MAPK signaling pathways

One of the best antipsychotics for treating schizophrenia and bipolar disorders is olanzapine (OLA). However, its use is restricted owing to unfavorable adverse effects as liver damage, dyslipidemia, and weight gain. The primary objective of the present investigation was to examine the signaling mechanisms that underlie the metabolic disruption generated by OLA. Besides, the potential protective effect of sulforaphane (SFN) and β-sitosterol (βSS) against obesity and metabolic toxicity induced by OLA were inspected as well. A total of five groups of male Wistar rats were established, including the control, OLA, SFN+OLA, βSS+OLA, and the combination + OLA groups. Hepatic histopathology, biochemical analyses, ultimate body weights, liver function, oxidative stress, and pro-inflammatory cytokines were evaluated. In addition to the relative expression of FOXO, the signaling pathways for PI3K/AKT, JAK/STAT3, and MAPK were assessed as well. All biochemical and hepatic histopathological abnormalities caused by OLA were alleviated by SFN and/or βSS. A substantial decrease in systolic blood pressure (SBP), proinflammatory cytokines, serum lipid profile parameters, hepatic MDA, TBIL, AST, and ALT were reduced through SFN or/and βSS. To sum up, the detrimental effects of OLA are mediated by alterations in the Akt/FOXO3a/ATG12, Ras/SOS2/Raf-1/MEK/ERK1/2, and Smad3,4/TGF-β signaling pathways. The administration of SFN and/or βSS has the potential to mitigate the metabolic deficit, biochemical imbalances, hepatic histological abnormalities, and the overall unfavorable consequences induced by OLA by modulating the abovementioned signaling pathways.

Differentially Induced Autophagy by Engineered Nanomaterial Treatment Has an Impact on Cellular Homeostasis and Cytotoxicity

Considering the increasing production of engineered nanomaterials (ENMs), new approach methodologies (NAMs) are essential for safe-by-design approaches and risk assessment. Our aim was to enhance screening strategies with a focus on reactivity-triggered toxicities. We applied in vitro tests to 10 selected benchmark ENMs in two cell models, lung epithelial A549 and differentiated THP-1 macrophage-like cells. Previously, we categorized ENMs based on surface reactivity. Here we elucidated their reactivity-triggered cytotoxicity and mode of action using the WST-1 assay (metabolic activity), LDH assay (cell membrane integrity), autophagosome detection, and proteomics. Nonreactive SiO2 NM-200 showed no significant impact on cell viability. Conversely, highly reactive CuO and ZnO (NM-110 and NM-111) disrupted cell homeostasis. Interestingly, moderately reactive TiO2 (NM-101 and NM-105) and CeO2 (NM-211 and NM-212), apparently without an adverse effect, induced autophagosome formation, evidencing autophagy as a defensive mechanism. Our improved in vitro testing strategy, combined with state-of-the-art reactivity information, screens ENMs for potential reactivity-triggered toxicity.

Golgi apparatus targeted therapy in cancer: Are we there yet?

Membrane trafficking within the Golgi apparatus plays a pivotal role in the intracellular transportation of lipids and proteins. Dysregulation of this process can give rise to various pathological manifestations, including cancer. Exploiting Golgi defects, cancer cells capitalise on aberrant membrane trafficking to facilitate signal transduction, proliferation, invasion, immune modulation, angiogenesis, and metastasis. Despite the identification of several molecular signalling pathways associated with Golgi abnormalities, there remains a lack of approved drugs specifically targeting cancer cells through the manipulation of the Golgi apparatus. In the initial section of this comprehensive review, the focus is directed towards delineating the abnormal Golgi genes and proteins implicated in carcinogenesis. Subsequently, a thorough examination is conducted on the impact of these variations on Golgi function, encompassing aspects such as vesicular trafficking, glycosylation, autophagy, oxidative mechanisms, and pH alterations. Lastly, the review provides a current update on promising Golgi apparatus-targeted inhibitors undergoing preclinical and/or clinical trials, offering insights into their potential as therapeutic interventions. Significantly more effort is required to advance these potential inhibitors to benefit patients in clinical settings.

Apoptosis-Cell Cycle-Autophagy Molecular Mechanisms Network in Heterogeneous Aggressive Phenotype Prostate Hyperplasia Primary Cell Cultures Have a Prognostic Role

Our study highlights the apoptosis, cell cycle, DNA ploidy, and autophagy molecular mechanisms network to identify prostate pathogenesis and its prognostic role. Caspase 3/7 expressions, cell cycle, adhesion glycoproteins, autophagy, nuclear shrinkage, and oxidative stress by flow-cytometry analysis are used to study the BPH microenvironment's heterogeneity. A high late apoptosis expression by caspases 3/7 activity represents an unfavorable prognostic biomarker, a dependent predictor factor for cell adhesion, growth inhibition by arrest in the G2/M phase, and oxidative stress processes network. The heterogeneous aggressive phenotype prostate adenoma primary cell cultures present a high S-phase category (>12%), with an increased risk of death or recurrence due to aneuploid status presence, representing an unfavorable prognostic biomarker, a dependent predictor factor for caspase 3/7 activity (late apoptosis and necrosis), and cell growth inhibition (G2/M arrest)-linked mechanisms. Increased integrin levels in heterogenous BPH cultures suggest epithelial-mesenchymal transition (EMT) that maintains an aggressive phenotype by escaping cell apoptosis, leading to the cell proliferation necessary in prostate cancer (PCa) development. As predictor biomarkers, the biological mechanisms network involved in apoptosis, the cell cycle, and autophagy help to establish patient prognostic survival or target cancer therapy development.

Autophagy and Female Fertility: Mechanisms, Clinical Implications, and Emerging Therapies

Autophagy, an evolutionarily conserved cellular mechanism essential for maintaining internal stability, plays a crucial function in female reproductive ability. In this review, we discuss the complex interplay between autophagy and several facets of female reproductive health, encompassing pregnancy, ovarian functions, gynecologic malignancies, endometriosis, and infertility. Existing research emphasizes the crucial significance of autophagy in embryo implantation, specifically in the endometrium, highlighting its necessity in ensuring proper fetal development. Although some knowledge has been gained, there is still a lack of research on the specific molecular impacts of autophagy on the quality of oocytes, the growth of follicles, and general reproductive health. Autophagy plays a role in the maturation, quality, and development of oocytes. It is also involved in reproductive aging, contributing to reductions in reproductive function that occur with age. This review explores the physiological functions of autophagy in the female reproductive system, its participation in reproductive toxicity, and its important connections with the endometrium and embryo. In addition, this study investigates the possibility of emerging treatment approaches that aim to modify autophagy, using both natural substances and synthetic molecules, to improve female fertility and reproductive outcomes. Additionally, this review intends to inspire future exploration into the intricate role of autophagy in female reproductive health by reviewing recent studies and pinpointing areas where current knowledge is lacking. Subsequent investigations should prioritize the conversion of these discoveries into practical uses in the medical field, which could potentially result in groundbreaking therapies for infertility and other difficulties related to reproduction. Therefore, gaining a comprehensive understanding of the many effects of autophagy on female fertility would not only further the field of reproductive biology but also open new possibilities for diagnostic and treatment methods.

Research progress on the role of PTEN deletion or mutation in the immune microenvironment of glioblastoma

Recent advances in immunotherapy represent a breakthrough in solid tumor treatment but the existing data indicate that immunotherapy is not effective in improving the survival time of patients with glioblastoma. The tumor microenvironment (TME) exerts a series of inhibitory effects on immune effector cells, which limits the clinical application of immunotherapy. Growing evidence shows that phosphate and tension homology deleted on chromosome ten (PTEN) plays an essential role in TME immunosuppression of glioblastoma. Emerging evidence also indicates that targeting PTEN can improve the anti-tumor immunity in TME and enhance the immunotherapy effect, highlighting the potential of PTEN as a promising therapeutic target. This review summarizes the function and specific upstream and downstream targets of PTEN-associated immune cells in glioblastoma TME, providing potential drug targets and therapeutic options for glioblastoma.

SVIP reduces IGFBP-2 expression and inhibits glioblastoma progression via stabilizing PTEN

Glioblastoma (GBM) presents significant challenges due to its invasive nature and genetic heterogeneity. In this study, we investigated the impact of Small VCP/P97-Interacting Protein (SVIP) on GBM progression. Our results revealed elevated expression of Insulin-like Growth Factor Binding Protein 2 (IGFBP-2) and STIP1 homology and U-box containing protein 1 (STUB1), coupled with reduced SVIP levels in GBM samples. Notably, high IGFBP-2 expression correlated with poor prognosis. Mechanistically, SVIP competitively inhibited STUB1, selectively binding to VCP/p97, thereby reducing PTEN degradation. This SVIP-mediated regulation exerted influence on the PTEN/PI3K/AKT/mTOR pathway, leading to the suppression of GBM progression. Co-localization experiments demonstrated that SVIP hindered PTEN ubiquitination and degradation by outcompeting STUB1 for VCP/p97 binding. Moreover, SVIP overexpression resulted in reduced activation of AKT/mTOR signaling and facilitated autophagy. In vivo experiments using a GBM xenograft model substantiated the tumor-suppressive effects of SVIP, evident by suppressed tumor growth, decreased IGFBP-2 expression, and improved survival rates. Collectively, our findings underscore the functional significance of SVIP in GBM progression. By inhibiting STUB1 and stabilizing PTEN, SVIP modulates the expression of IGFBP-2 and attenuates the activation of the PI3K/AKT/mTOR pathway, thereby emerging as a promising therapeutic target for GBM treatment.

Genistein alleviates doxorubicin-induced cardiomyocyte autophagy and apoptosis via ERK/STAT3/c-Myc signaling pathway in rat model

Doxorubicin (Dox) is a highly effective anti-neoplastic agent. Still, its utility in the clinic has been hindered by toxicities, including vomiting, hematopoietic suppression and nausea, with cardiotoxicity being the most serious side effect. Genistein (Gen) is a natural product with extensive biological effects, including anti-oxidation, anti-tumor, and cardiovascular protection. This study evaluated whether Gen protected the heart from Dox-induced cardiotoxicity and explored the underlying mechanisms. Male Sprague-Dawley (SD) rats were categorized into control (Ctrl), genistein (Gen), doxorubicin (Dox), genistein 20 mg/kg/day + doxorubicin (Gen20 + Dox) and genistein 40 mg/kg/day + doxorubicin (Gen40 + Dox) groups. Six weeks after injection, immunohistochemistry (IHC), transmission electron microscopy (TEM), and clinical cardiac function analyses were performed to evaluate the effects of Dox on cardiac function and structural alterations. Furthermore, each heart histopathological lesions were given a score of 0-3 in compliance with the articles for statistical analysis. In addition, molecular and cellular response of H9c2 cells toward Dox were evaluated through western blotting, Cell Counting Kit-8 (CCK8), AO staining and calcein AM/PI assay. Dox (5 μM in vitro and 18 mg/kg in vivo) was used in this study. In vivo, low-dose Gen pretreatment protected the rat against Dox-induced cardiac dysfunction and pathological remodeling. Gen inhibited extracellular signal-regulated kinase1/2 (ERK1/2)'s phosphorylation, increased the protein levels of STAT3 and c-Myc, and decreased the autophagy and apoptosis of cardiomyocytes. U0126, a MEK1/2 inhibitor, can mimic the effect of Gen in protecting against Dox-induced cytotoxicity both in vivo and in vitro. Molecular docking analysis showed that Gen forms a stable complex with ERK1/2. Gen protected the heart against Dox-induced cardiomyocyte autophagy and apoptosis through the ERK/STAT3/c-Myc signaling pathway.

Hesperetin regulates PI3K/Akt and mTOR pathways to exhibit its antiproliferative effect against colon cancer cells

Hesperetin, a citrus flavonoid, has been a widely studied anticancer agent against many types of cancers, but the exact mechanism of efficacy is still unrevealed. Therefore, this study has attempted to delineate the mechanical aspect of hesperetin's anticancer efficacy against colon cancer using immunoblotting, scanning, and transmission electron microscopic studies. The treatment with hesperetin (25 and 50 µM) has significantly (p < 0.0001) curbed down the proliferation and cell viability of HCT-15 cells in a concentration as well as time dependent manner. Hesperetin was able to achieve this through the induction of caspase-dependent apoptosis. Moreover, hesperetin effectively inhibited phosphorylation of Akt with a parallel increase in PTEN expression thereby inhibiting the PI3K signaling axis, which contributes to the suppression of proliferation. In addition, hesperetin enhanced autophagy through dephosphorylating mTOR, one of the downstream targets of Akt with simultaneous acceleration in Beclin-1 and LC3-II expression levels. Interestingly, hesperetin enhanced the effects of Akt inhibitor LY294002 and mTOR inhibitor rapamycin. This study documented the potential of hesperetin to induce apoptosis through simultaneous acceleration over the autophagic process in colon cancer cells. Thus, hesperetin played a beneficial therapeutic role in preventing colon carcinoma growth by regulating the Akt and mTOR signaling axis.

SNX14 inhibits autophagy via the PI3K/AKT/mTOR signaling cascade in breast cancer cells

BACKGROUND

Sorting nexin 14 (SNX14) is a member of the sorting junction protein family. Its specific roles in cancer development remain unclear. Therefore, in this study, we aimed to determine the effects and underlying mechanisms of SNX14 on autophagy of breast cancer cells to aid in the therapeutic treatment of breast cancer.

METHODS

In this study, we performed in vitro experiments to determine the effect of SNX14 on breast cancer cell growth. Moreover, we used an MCF7 breast cancer tumor-bearing mouse model to confirm the effect of SNX14 on tumor cell growth in vivo. We also performed western blotting and quantitative polymerase chain reaction to identify the mechanism by which SNX14 affects breast cancer MCF7 cells.

RESULTS

We found that SNX14 regulated the onset and progression of breast cancer by promoting the proliferation and inhibiting the autophagy of MCF7 breast cancer cells. In vivo experiments further confirmed that SNX14 knockdown inhibited the tumorigenicity and inhibited the growth of tumor cells in tumor tissues of nude mice. In addition, western blotting analysis revealed that SNX14 modulate the autophagy of MCF7 breast cancer cells via the phosphoinositide 3-kinase/protein kinase B/mechanistic target of rapamycin kinase signaling pathway.

CONCLUSION

Our findings indicate that SNX14 is an essential tumor-promoting factor in the development of breast cancer.

Insights into the role of mitophagy in lung cancer: current evidence and perspectives

Lung cancer, recognized globally as a leading cause of malignancy-associated morbidity and mortality, is marked by its high prevalence and lethality, garnering extensive attention within the medical community. Mitophagy is a critical cellular process that plays a crucial role in regulating metabolism and ensuring quality control within cells. Its relevance to lung cancer has garnered significant attention among researchers and scientists. Mitophagy's involvement in lung cancer encompasses its initiation, progression, metastatic dissemination and treatment. The regulatory landscape of mitophagy is complex, involving numerous signaling proteins and pathways that may exhibit aberrant alterations or mutations within the tumor environment. In the field of treatment, the regulation of mitophagy is considered key to determining cancer chemotherapy, radiation therapy, other treatment options, and drug resistance. Contemporary investigations are directed towards harnessing mitophagy modulators, both inhibitors and activators, in therapeutic strategies, with an emphasis on achieving specificity to minimize collateral damage to healthy cellular populations. Furthermore, molecular constituents and pathways affiliated with mitophagy, serving as potential biomarkers, offer promising avenues for enhancing diagnostic accuracy, prognostic assessment, and prediction of therapeutic responses in lung cancer. Future endeavors will also involve investigating the impact of mitophagy on the composition and function of immune cells within the tumor microenvironment, aiming to enhance our understanding of how mitophagy modulates the immune response to lung cancer. This review aims to comprehensively overview recent advancements about the role of mitophagy in the tumor genesis, progenesis and metastasis, and the impact of mitophagy on the treatment of lung cancer. We also discussed the future research direction of mitophagy in the field of lung cancer.

To eat or not to eat: a critical review on the role of autophagy in prostate carcinogenesis and prostate cancer therapeutics

Around 1 in 7 men will be diagnosed with prostate cancer during their lifetime. Many strides have been made in the understanding and treatment of this malignancy over the years, however, despite this; treatment resistance and disease progression remain major clinical concerns. Recent evidence indicate that autophagy can affect cancer formation, progression, and therapeutic resistance. Autophagy is an evolutionarily conserved process that can remove unnecessary or dysfunctional components of the cell as a response to metabolic or environmental stress. Due to the emerging importance of autophagy in cancer, targeting autophagy should be considered as a potential option in disease management. In this review, along with exploring the advances made on understanding the role of autophagy in prostate carcinogenesis and therapeutics, we will critically consider the conflicting evidence observed in the literature and suggest how to obtain stronger experimental evidence, as the application of current findings in clinical practice is presently not viable.

Celastrol enhances the viability of random-pattern skin flaps by regulating autophagy through the AMPK-mTOR-TFEB axis

In reconstructive and plastic surgery, random-pattern skin flaps (RPSF) are often used to correct defects. However, their clinical usefulness is limited due to their susceptibility to necrosis, especially on the distal side of the RPSF. This study validates the protective effect of celastrol (CEL) on flap viability and explores in terms of underlying mechanisms of action. The viability of different groups of RPSF was evaluated by survival zone analysis, laser doppler blood flow, and histological analysis. The effects of CEL on flap angiogenesis, apoptosis, oxidative stress, and autophagy were evaluated by Western blot, immunohistochemistry, and immunofluorescence assays. Finally, its mechanistic aspects were explored by autophagy inhibitor and Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) inhibitor. On the seventh day after surgery, the survival area size, blood supply, and microvessel count of RPSF were augmented following the administration of CEL. Additionally, CEL stimulated angiogenesis, suppressed apoptosis, and lowered oxidative stress levels immediately after elevated autophagy in ischemic regions; These effects can be reversed using the autophagy inhibitor chloroquine (CQ). Specifically, CQ has been observed to counteract the protective impact of CEL on the RPSF. Moreover, it has also been discovered that CEL triggers the AMPK-mTOR-TFEB axis activation in the area affected by ischemia. In CEL-treated skin flaps, AMPK inhibitors were demonstrated to suppress the AMPK-mTOR-TFEB axis and reduce autophagy levels. This investigation suggests that CEL benefits the survival of RPSF by augmenting angiogenesis and impeding oxidative stress and apoptosis. The results are credited to increased autophagy, made possible by the AMPK-mTOR-TFEB axis activation.

Autophagy genes and signaling pathways in endometrial decidualization and pregnancy complications

Autophagy is a process that occurs in almost all eukaryotic cells and this process is controlled by several molecular processes. Its biological roles include the provision of energy, the maintenance of cell homeostasis, and the promotion of aberrant cell death. The importance of autophagy in pregnancy is gradually becoming recognized. In literature, it has been indicated that autophagy has three different effects on the onset and maintenance of pregnancy: embryo (embryonic development), feto-maternal immune crosstalk, and maternal (decidualization). In humans, proper decidualization is a major predictor of pregnancy accomplishment and it can be influenced by different factors. This review highlights the genes, pathways, regulation, and function of autophagy in endometrial decidualization and other involved factors in this process.

Melatonin suppresses TLR4-mediated RSV infection in the central nervous cells by inhibiting NLRP3 inflammasome formation and autophagy

Respiratory syncytial virus (RSV) infects neuronal cells in the central nervous system (CNS), resulting in neurological symptoms. In the present study, we intended to explore the mechanism of RSV infection-induced neuroinflammatory injury from the perspective of the immune response and sought to identify effective protective measures against the injury. The findings showed that toll-like receptor 4 (TLR4) was activated after RSV infection in human neuronal SY5Y cells. Furthermore, TLR4 activation induced autophagy and apoptosis in neuronal cells, promoted the formation of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, and increased the secretion of downstream inflammatory cytokines such as interleukin-1β (IL-1β), interleukin-18 (IL-18) and tumour necrosis factor-α (TNF-α). Interestingly, blockade of TLR4 or treatment with exogenous melatonin significantly suppressed TLR4 activation as well as TLR4-mediated apoptosis, autophagy and immune responses. Therefore, we infer that melatonin may act on the TLR4 to ameliorate RSV-induced neuronal injury, which provides a new therapeutic target for RSV infection.

Design, Synthesis, Formulation, and Bioevaluation of Trisubstituted Triazines as Highly Selective mTOR Inhibitors for the Treatment of Human Breast Cancer

The aberrant activation of the PI3K/mTOR signaling pathway is implicated in various human cancers. Thus, the development of inhibitors targeting mTOR has attracted considerable attention. In this study, we used a structure-based drug design strategy to discover a highly potent and kinase-selective mTOR inhibitor 24 (PT-88), which demonstrated an mTOR inhibitory IC50 value of 1.2 nM without obvious inhibition against another 195 kinases from the kinase profiling screening. PT-88 displayed selective inhibition against MCF-7 cells (IC50: 0.74 μM) with high biosafety against normal cells, in which autophagy induced by mTOR inhibition was implicated. After successful encapsulation in a lipodisc formulation, PT-88 demonstrated favorable pharmacokinetic and biosafety profiles and exerted a large antitumor effect in an MCF-7 subcutaneous bearing nude mice model. Our study shows the discovery of a highly selective mTOR inhibitor using a structure-based drug discovery strategy and provides a promising antitumor candidate for future study and development.

JunB condensation attenuates vascular endothelial damage under hyperglycemic condition

Endothelial damage is the initial and crucial factor in the occurrence and development of vascular complications in diabetic patients, contributing to morbidity and mortality. Although hyperglycemia has been identified as a damaging effector, the detailed mechanisms remain elusive. In this study, identified by ATAC-seq and RNA-seq, JunB reverses the inhibition of proliferation and the promotion of apoptosis in human umbilical vein endothelial cells treated with high glucose, mainly through the cell cycle and p53 signaling pathways. Furthermore, JunB undergoes phase separation in the nucleus and in vitro, mediated by its intrinsic disordered region and DNA-binding domain. Nuclear localization and condensation behaviors are required for JunB-mediated proliferation and apoptosis. Thus, our study uncovers the roles of JunB and its coacervation in repairing vascular endothelial damage caused by high glucose, elucidating the involvement of phase separation in diabetes and diabetic endothelial dysfunction.

PTPN2 inhibits the proliferation of psoriatic keratinocytes by dephosphorylation of STAT3

Psoriasis is a recurrent and protracted disease that severely impacts the patient's physical and mental health. Thus, there is an urgent need to explore its pathogenesis to identify therapeutic targets. The expression level of protein tyrosine phosphatase nonreceptor type 2 (PTPN2) was analyzed by immunohistochemistry techniques in psoriatic tissues and imiquimod-induced psoriatic mouse models. PTPN2 and signal transducer and activator of transcription 3 (STAT3) were overexpressed or silenced in human keratinocytes or an interleukin (IL)-6-induced psoriasis HaCaT cell model using overexpression plasmid transfection or small interfering RNA technology in vitro, and the effects of PTPN2 on STAT3, HaCaT cell function, and autophagy levels were investigated using reverse transcription-quantitative polymerase chain reaction, Western blot, Cell Counting Kit 8, 5-ethynyl-20-deoxyuridine, flow cytometry, and transmission electron microscopy. PTPN2 expression was found to be significantly downregulated in psoriatic tissues. Then, the in vitro antipsoriatic properties of PTPN2 were investigated in an IL-6-induced psoriasis-like cell model, and the results demonstrated that inhibition of keratinocyte proliferation by PTPN2 may be associated with elevated STAT3 dephosphorylation and autophagy levels. These findings provide novel insights into the mechanisms of autophagy in psoriatic keratinocytes and may be essential for developing new therapeutic strategies to improve inflammatory homeostasis in psoriatic patients.

Deregulation of circRNA hsa_circ_0009109 promotes tumor growth and initiates autophagy by sponging miR-544a-3p in gastric cancer

Background

Autophagy death of cancer cells is detrimental to apoptosis induced by therapeutic drugs, which promotes tumor progression to a certain extent. Increasing reports have demonstrated the regulatory role of circular RNAs (circRNAs) in autophagy. Here, we aimed to determine the role of hsa_circ_0009109 in autophagy in gastric cancer (GC).

Methods

The effects of hsa_circ_0009109 on autophagy were examined using quantitative real-time polymerase chain reaction (qPCR), transmission electron microscopy, Western blot, and immunofluorescence. The mechanism of hsa_circ_0009109 regulating the miR-544a-3p/bcl-2 axis was analysed using fluorescence in situ hybridization, dual-luciferase reporter, and rescue experiments.

Results

Functional testing indicated that hsa_circ_0009109 was significantly down-expressed in GC tissues and cell lines. A reduction in cytoplasmic-derived hsa_circ_0009109 could promote GC progression by accelerating cell proliferation, enhancing migration and invasion, inhibiting apoptosis, and accelerating the cell cycle progression. Besides, hsa_circ_0009109 was found to exert the effect of an autophagy inhibitor such as 3-Methyladenine (3-MA), which was manifested by the weakening of the immunofluorescence of LC3B and the reduction in autophagy-related proteins after overexpression of hsa_circ_0009109, while increased autophagosomes were observed after interference with hsa_circ_0009109. Subsequently, the crosstalk between hsa_circ_0009109 and miR-544a-3p/bcl-2 was verified using dual-luciferase reporter assay. The autophagy status was altered under the regulation of the hsa_circ_0009109-targeted miR-544a-3p/bcl-2 axis.

Conclusions

The hsa_circ_0009109 mediated a novel autophagy regulatory network through targeting the miR-544a-3p/bcl-2 axis, which may shed new light on the exploration of therapeutic targets for the clinical treatment of GC.

Impact of Complex Apoptotic Signaling Pathways on Cancer Cell Sensitivity to Therapy

Anticancer drugs induce apoptotic and non-apoptotic cell death in various cancer types. The signaling pathways for anticancer drug-induced apoptotic cell death have been shown to differ between drug-sensitive and drug-resistant cells. In atypical multidrug-resistant leukemia cells, the c-Jun/activator protein 1 (AP-1)/p53 signaling pathway leading to apoptotic death is altered. Cancer cells treated with anticancer drugs undergo c-Jun/AP-1-mediated apoptotic death and are involved in c-Jun N-terminal kinase activation and growth arrest- and DNA damage-inducible gene 153 (Gadd153)/CCAAT/enhancer-binding protein homologous protein pathway induction, regardless of the p53 genotype. Gadd153 induction is associated with mitochondrial membrane permeabilization after anticancer drug treatment and involves a coupled endoplasmic reticulum stress response. The induction of apoptosis by anticancer drugs is mediated by the intrinsic pathway (cytochrome c, Cyt c) and subsequent activation of the caspase cascade via proapoptotic genes (e.g., Bax and Bcl-xS) and their interactions. Anticancer drug-induced apoptosis involves caspase-dependent and caspase-independent pathways and occurs via intrinsic and extrinsic pathways. The targeting of antiapoptotic genes such as Bcl-2 enhances anticancer drug efficacy. The modulation of apoptotic signaling by Bcl-xS transduction increases the sensitivity of multidrug resistance-related protein-overexpressing epidermoid carcinoma cells to anticancer drugs. The significance of autophagy in cancer therapy remains to be elucidated. In this review, we summarize current knowledge of cancer cell death-related signaling pathways and their alterations during anticancer drug treatment and discuss potential strategies to enhance treatment efficacy.

Combination of AAV-delivered tumor suppressor PTEN with anti-PD-1 loaded depot gel for enhanced antitumor immunity

Recent clinical studies have shown that mutation of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene in cancer cells may be associated with immunosuppressive tumor microenvironment (TME) and poor response to immune checkpoint blockade (ICB) therapy. Therefore, efficiently restoring PTEN gene expression in cancer cells is critical to improving the responding rate to ICB therapy. Here, we screened an adeno-associated virus (AAV) capsid for efficient PTEN gene delivery into B16F10 tumor cells. We demonstrated that intratumorally injected AAV6-PTEN successfully restored the tumor cell PTEN gene expression and effectively inhibited tumor progression by inducing tumor cell immunogenic cell death (ICD) and increasing immune cell infiltration. Moreover, we developed an anti-PD-1 loaded phospholipid-based phase separation gel (PPSG), which formed an in situ depot and sustainably release anti-PD-1 drugs within 42 days in vivo. In order to effectively inhibit the recurrence of melanoma, we further applied a triple therapy based on AAV6-PTEN, PPSG@anti-PD-1 and CpG, and showed that this triple therapy strategy enhanced the synergistic antitumor immune effect and also induced robust immune memory, which completely rejected tumor recurrence. We anticipate that this triple therapy could be used as a new tumor combination therapy with stronger immune activation capacity and tumor inhibition efficacy.

TORC1 mediated regulation of mitochondrial integrity and calcium ion homeostasis by Wat1/mLst8 in S. pombe

The mTOR complexes play a fundamental role in mitochondrial biogenesis and cellular homeostasis. Wat1, an ortholog of mammalian Lst8 is an important component of TOR complex and is essential for the regulation of downstream signaling. Earlier we reported the role of Wat1 in oxidative stress response. Here, we have shown that the abrogation of wat1 causes respiratory defects and mitochondrial depolarization that leads to a decrease in ATP production. The confocal and electron microscopy in wat1Δ cells revealed the fragmented mitochondrial morphology implying its role in mitochondrial fission. Furthermore, we also showed its role in autophagy and the maintenance of calcium ion homeostasis. Additionally, tor2-287 mutant cells also exhibit defects in mitochondrial integrity indicating the TORC1-dependent involvement of Wat1 in the maintenance of mitochondrial homeostasis. The interaction studies of Wat1 and Tor2 with Por1 and Mmm1 proteins revealed a plausible cross-talk between mitochondria and endoplasmic reticulum through the Mitochondria-associated membranes (MAM) and endoplasmic reticulum-mitochondria encounter structure (ERMES) complex, involving TORC1. Taken together, this study demonstrates the involvement of Wat1/mLst8 in harmonizing various mitochondrial functions, redox status, and Ca2+ homeostasis.

Enhancing autophagy leads to increased cell death in radiation-treated cervical cancer cells

This study was carried out to determine the effect of autophagy modulation in radiation treatment of cervical cancer cells. HeLa and CaSki cells were irradiated with γ-rays (2 Gy/min) after treatment with an autophagy inducer (rapamycin) and inhibitor (3-MA). Expression of LC3 and cell death in two cell preparations were examined. In addition, expression of Caspase-3 and PARP were examined after radiation alone and with autophagy inhibitor treatment. A notable increment of LC3 expression was detected after radiation in both cell lines. Cell viability was observed to decrease in 3-MA-treated cells compared to radiation alone, and even further in rapamycin-treated cells. Apoptosis was confirmed to occur later than autophagy in radiation treatment, and inhibition of autophagy derived a decrease in apoptosis. In conclusion, radiation-induced autophagy may be regulated by modulators, and autophagy augmentation yields an increase in cervical cancer cell death under radiation.Impact statementWhat is already known on this subject? Autophagy is known to contribute both to tumour cell survival and death against radiation therapy. The effect of induction or inhibition of radiation-induced autophagy on cervical cancer cell death is not clear.What the results of this study add? Cell viability was observed to decrease in 3-MA-treated cells compared to radiation alone, and even further in rapamycin-treated cells. Apoptosis occurred later than autophagy in radiation treatment, and inhibition of autophagy derived a decrease in apoptosis.What the implications are of these findings for clinical practice and/or further research? Our results suggest that radiation-induced autophagy may be regulated by modulators, and autophagy augmentation yields an increase in cervical cancer cell death under radiation.

Medical Gas Plasma Technology Combines with Antimelanoma Therapies and Promotes Immune-Checkpoint Therapy Responses

Strategies to improve activity and selectivity are major goals in oncological drug development. Medical gas plasma therapy has been subject to intense research in dermatooncology recently. Based on partial gas ionization, this approach is exceptional in generating a variety of reactive oxygen species simultaneously that can be applied locally at the tumor side. It is hypothesized that combined gas plasma treatment can potentiate drug responses in the treatment of melanoma. Using a plasma jet approved as medical device in Europe, a systematic screening of 46 mitochondria-targeted drugs identifies five agents synergizing in vitro and in vivo. Increased intratumoral leucocyte infiltration points to immunomodulatory aspects of the treatment, motivating to investigate responses to immune checkpoint blockade in combination with plasma. Tumor growth is monitored based on bioluminescent imaging, and single-cell suspensions are retrieved from each tumor to characterize tumor-infiltrating leucocytes using multicolor flow cytometry. Gene expression profiling is done using a validated NanoString panel targeting 770 genes specifically designed for immuno-oncological research. Cell type abundancies are characterized from bulk RNA samples using the CIBERSORT computational framework. Collectively, the results indicate that local application of medical gas plasma technology synergizes with mitochondria-targeted drugs and anti-PD1 checkpoint therapy in treating melanoma.

Novel Insight into the Cellular and Molecular Signalling Pathways on Cancer Preventing Effects of Hibiscus sabdariffa: A Review

A category of diseases known as cancer includes abnormal cell development and the ability to infiltrate or spread to other regions of the body, making them a major cause of mortality worldwide. Chemotherapy, radiation, the use of cytotoxic medicines, and surgery are the mainstays of cancer treatment today. Plants or products produced from them hold promise as a source of anti-cancer medications that have fewer adverse effects. Due to the presence of numerous phytochemicals that have been isolated from various parts of the Hibiscus sabdariffa (HS) plant, including anthocyanin, flavonoids, saponins, tannins, polyphenols, organic acids, caffeic acids, citric acids, protocatechuic acid, and others, extracts of this plant have been reported to have anti-cancer effects. These compounds have been shown to reduce cancer cell proliferation, induce apoptosis, and cause cell cycle arrest. They also increase the expression levels of the cell cycle inhibitors (p53, p21, and p27) and the pro-apoptotic proteins (BAD, Bax, caspase 3, caspase 7, caspase 8, and caspase 9). This review highlights various intracellular signalling pathways involved in cancer preventive potential of HS.

Baicalin promotes random-pattern skin flap survival by inducing autophagy via AMPK-regulated TFEB nuclear transcription

The random-pattern skin flap is a generally used technique to cover the soft tissue defect, while its application is often constrained by complications after the flap transplant. Necrosis of the flap remains a principal obstacle. The purpose of this study was to investigate the effect of Baicalin on skin flap survival and its mechanism. First of all, we discovered that administering Baicalin stimulated cell migration and boosted the formation of capillary tubes in human umbilical vein endothelial cells. Then, we detected that Baicalin reduced apoptosis-induced oxidative stress by using western blot and oxidative stress test kit. After that, we observed that Baicalin increased autophagy and utilized 3MA to block autophagy augmentation substantially reversing the effects of Baicalin therapy. Furthermore, we uncovered the underlying mechanisms of Baicalin-induced autophagy via AMPK-regulated TFEB nuclear transcription. Finally, our in vivo experiment findings showed that Baicalin reduces oxidative stress, inhibits apoptosis, promotes angiogenesis, and boosts the levels of autophagy. After autophagy was blocked, substantially reversing the effects of Baicalin therapy. Our study indicated that Baicalin-induced autophagy via AMPK regulated TFEB nuclear transcription and then promotes angiogenesis and against oxidative stress and apoptotic promotes skin flap survival. These findings highlight the therapeutic potential for the clinical application of Baicalin in the future.

The role of redox-mediated lysosomal dysfunction and therapeutic strategies

Redox homeostasis refers to the dynamic equilibrium between oxidant and reducing agent in the body which plays a crucial role in maintaining normal physiological activities of the body. The imbalance of redox homeostasis can lead to the development of various human diseases. Lysosomes regulate the degradation of cellular proteins and play an important role in influencing cell function and fate, and lysosomal dysfunction is closely associated with the development of various diseases. In addition, several studies have shown that redox homeostasis plays a direct or indirect role in regulating lysosomes. Therefore, this paper systematically reviews the role and mechanisms of redox homeostasis in the regulation of lysosomal function. Therapeutic strategies based on the regulation of redox exerted to disrupt or restore lysosomal function are further discussed. Uncovering the role of redox in the regulation of lysosomes helps to point new directions for the treatment of many human diseases.

TRAF6 regulates autophagy and apoptosis of melanoma cells through c-Jun/ATG16L2 signaling pathway

Autophagy and apoptosis are essential processes that participate in cell death and maintain cellular homeostasis. Dysregulation of these biological processes results in the development of diseases, including cancers. Therefore, targeting the interaction between apoptosis and autophagy offers a potential strategy for cancer therapy. Melanoma is the most lethal skin cancer. We previously found that tumor necrosis factor receptor-associated factor 6 (TRAF6) is overexpressed in melanoma and benefits the malignant phenotype of melanoma cells. Additionally, TRAF6 promotes the activation of cancer-associated fibroblasts in melanoma. However, the role of TRAF6 in autophagy and apoptosis remains unclear. In this study, we found that knockdown of TRAF6 induced both apoptosis and autophagy in melanoma cells. Transcriptomic data and real-time PCR analysis demonstrated reduced expression of autophagy related 16 like 2 (ATG16L2) in TRAF6-deficient melanoma cells. ATG16L2 knockdown resulted in increased autophagy and apoptosis. Mechanism studies confirmed that TRAF6 regulated ATG16L2 expression through c-Jun. Importantly, targeting TRAF6 with cinchonine, a TRAF6 inhibitor, effectively suppressed the growth of melanoma cells by inducing autophagy and apoptosis through the TRAF6/c-Jun/ATG16L2 signaling pathway. These findings highlight the pivotal role of TRAF6 in regulating autophagy and apoptosis in melanoma, emphasizing its significance as a novel therapeutic target for melanoma treatment.

Antitumor activity of 5-fluorouracil polymeric nanogel synthesized by gamma radiation on a rat model of colon carcinoma: a proposed mechanism

The use of 5-fluorouracil (5-FU) is associated with multifaceted challenges and poor pharmacokinetics. Accordingly, our study was designed to prepare 5-FU nanogel as a new form of the colon cancer chemotherapeutic drug 5-FU using polyacrylic acid and gelatin hybrid nanogel as efficient drug carriers. Alongside the in vivo chemotherapeutic evaluation, the anti-proliferative and anti-apoptotic efficacy were carried out for 5-FU nanogel against 1,2-dimethylhydrazine (DMH, 20 mg/kg) and γ-radiation (4 Gy)-prompted colon dysplasia in rats compared to 5-FU. The morphology and size of 5-FU nanogel were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS) in addition to cytotoxicity assay. The expression of phosphoinositide-3-kinase (PI3K)/Akt, mammalian target of rapamycin (mTOR); Toll-like receptor2 (TLR2)/nuclear factor kappa B), adenosine monophosphate (AMP)-activated protein kinase (AMPK) and its downstream autophagy-related genes in addition to apoptotic markers were measured in colon tissues. Results: 5-FU nanogel reduced the levels of the TLR2/ NF-κβ as well as the expression of PI3K/AKT/mTOR. Moreover, it promoted autophagy through the activation of the AMPK and its downstream targets which consequently augmented the intrinsic and extrinsic apoptotic pathways. Conclusion: Collectively, these data might strengthen the therapeutic potential of 5-FU nanogel which can be used as an antitumor product for colon cancer.

Nickel nanoparticles induce autophagy and apoptosis via HIF-1α/mTOR signaling in human bronchial epithelial cells

With the rapid development of nanotechnology, the potential adverse health effects of nanoparticles have been caught more attention and become global concerns. However, the underlying mechanisms in metal nanoparticle-induced toxic effects are still largely obscure. In this study, we investigated whether exposure to nickel nanoparticles (Nano-Ni) and titanium dioxide nanoparticles (Nano-TiO2) would alter autophagy and apoptosis levels in normal human bronchial epithelial BEAS-2B cells and the underlying mechanisms involved in this process. Our results showed that the expressions of autophagy- and apoptosis-associated proteins were dysregulated in cells exposed to Nano-Ni. However, exposure to the same doses of Nano-TiO2 had no significant effects on these proteins. In addition, exposure to Nano-Ni, but not Nano-TiO2, led to nuclear accumulation of HIF-1α and decreased phosphorylation of mTOR in BEAS-2B cells. Inhibition of HIF-1α by CAY10585 abolished Nano-Ni-induced decreased phosphorylation of mTOR, while activation of mTOR by MHY1485 did not affect Nano-Ni-induced nuclear accumulation of HIF-1α. Furthermore, both HIF-1α inhibition and mTOR activation abolished Nano-Ni-induced autophagy but enhanced Nano-Ni-induced apoptosis. Blockage of autophagic flux by Bafilomycin A1 exacerbated Nano-Ni-induced apoptosis, while activation of autophagy by Rapamycin effectively rescued Nano-Ni-induced apoptosis. In conclusion, our results demonstrated that Nano-Ni exposure caused increased levels of autophagy and apoptosis via the HIF-1α/mTOR signaling axis. Nano-Ni-induced autophagy has a protective role against Nano-Ni-induced apoptosis. These findings provide us with further insight into Nano-Ni-induced toxicity.

Histone Deacetylase Inhibition and Autophagy Modulation Induces a Synergistic Antiproliferative Effect and Cell Death in Cholangiocarcinoma Cells

Cholangiocarcinoma, also known as biliary tract cancer, is an aggressive adenocarcinoma arising from epithelial cells lining the intra- and extrahepatic biliary system. The effects of autophagy modulators and histone deacetylase (HDAC) inhibitors in cholangiocarcinoma are not fully known. It is essential to understand the molecular mechanisms and the effects of HDAC inhibitors in the context of cholangiocarcinoma. The antiproliferative effect of different HDAC inhibitors and autophagy modulation was investigated by the MTT cell viability assay in TFK-1 and EGI-1 cholangiocarcinoma cell lines. Combination indexes were calculated using CompuSyn software. Consequently, apoptosis was detected by Annexin V/PI staining. The effect of the drugs on the cell cycle was measured by the propidium iodide staining. The HDAC inhibition was confirmed via acetylated histone protein levels by western blotting. HDAC inhibitors, MS-275 and romidepsin, showed a better synergistic effect with the nocodazole combination. The combination treatment exerted its growth inhibitory effect by cell cycle arrest and induction of apoptosis. The cell cycle analysis of the combination treatment showed that the S phase and G2/M phase were achieved. Moreover, the necrotic and apoptotic cell population increased after single HDAC inhibitors and combination treatment. The anti-cancer effect of HDAC inhibitors is revealed by acetylation levels of histones. While acetylation levels were increased in response to HDAC inhibitors and autophagy modulator combinations, the HDAC expression decreased. This study highlights the importance of the combination of HDAC inhibition and autophagy modulators and demonstrates a synergistic effect, which could be a promising therapy and novel treatment approach for cholangiocarcinoma.

Breast Tumor Cells Evade the Cytotoxic Action of Anastrozole, Aspirin, and Clopidogrel Cocktail

Globally, breast cancer is among the most frequently diagnosed and common cause of death among women. Aromatase inhibitors, such as anastrozole, are one of the first-line therapies used in the treatment of breast cancer in postmenopausal women; however, thromboembolic complications are common. Thus, this study investigated the combined effects of anastrozole and antiplatelet therapies, aspirin and clopidogrel, on breast cancer cytotoxicity and survival in vitro. Breast cancer cell lines (MCF-7 and T47D) were treated with varying Cmax concentrations of anastrozole and/or antiplatelet therapies for 24 h. A wound-healing scratch assay was used to measure migration and the WST-1 assay for cellular proliferation. An autophagy/cytotoxicity dual staining kit was used to assay cell death and survival. Changes in cell morphology were assessed using scanning electron microscopy. Data were analyzed with Statistica software. Our findings showed that sub-phenotypic differences exist between the luminal-A breast cancer cell lines, with T47D cells being more aggressive than MCF-7 cells. Cellular proliferation and migration responded in a dose-dependent manner for the different treatment groups. Notably, anastrozole combined with aspirin and clopidogrel mediated higher levels of cell survival than each agent individually, with autophagy levels being significantly increased in comparison to that induced with antiplatelet therapy alone.

Longitudinal effects of ketamine on cell proliferation and death in the CNS of zebrafish

Zebrafish is known for its widespread neurogenesis and regenerative capacity, as well as several biological advantages, which turned it into a relevant animal model in several areas of research, namely in toxicological studies. Ketamine is a well-known anesthetic used both in human as well as veterinary medicine, due to its safety, short duration and unique mode of action. However, ketamine administration is associated with neurotoxic effects and neuronal death, which renders its use on pediatric medicine problematic. Thus, the evaluation of ketamine effects administration at early stages of neurogenesis is of pivotal importance. The 1-4 somites stage of zebrafish embryo development corresponds to the beginning of segmentation and formation of neural tube. In this species, as well as in other vertebrates, longitudinal studies are scarce, and the evaluation of ketamine long-term effects in adults is poorly understood. This study aimed to assess the effects of ketamine administration at the 1-4 somites stage, both in subanesthetic and anesthetic concentrations, in brain cellular proliferation, pluripotency and death mechanisms in place during early and adult neurogenesis. For that purpose, embryos at the 1-4 somites stage (10,5hours post fertilization - hpf) were distributed into study groups and exposed for 20minutes to ketamine concentrations at 0.2/0.8mg/mL. Animals were grown until defined check points, namely 50 hpf, 144 hpf and 7 months adults. The assessment of the expression and distribution patterns of proliferating cell nuclear antigen (PCNA), of sex-determining region Y-box 2 (Sox 2), apoptosis-inducing factor (AIF) and microtubule-associated protein 1 light chain 3 (LC3) was performed by Western-blot and immunohistochemistry. The results evidenced the main alterations in 144 hpf larvae, namely in autophagy and in cellular proliferation at the highest concentration of ketamine (0.8mg/mL). Nonetheless, in adults no significant alterations were seen, pointing to a return to a homeostatic stage. This study allowed clarifying some of the aspects pertaining the longitudinal effects of ketamine administration regarding the CNS capacity to proliferate and activate the appropriate cell death and repair mechanisms leading to homeostasis in zebrafish. Moreover, the results indicate that ketamine administration at 1-4 somites stage in the subanesthetic and anesthetic concentrations despite some transitory detrimental effects at 144 hpf, is long-term safe for CNS, which are newly and promising results in this research field.

Echinacoside ameliorates 5-fluorouracil-induced endothelial injury and senescence through SIRT1 activation

Echinacoside (ECH) is a natural bioactive component with antioxidant, anti-inflammatory, anti-apoptosis, and anti-tumor properties. In the current study, we explore the ECH-mediated protective effect and underlying mechanism of 5-fluorouracil (5-FU)-induced endothelial injury and senescence in the Human umbilical vein endothelial cells (HUVECs). In HUVECs, Cell viability, Apoptosis and Senescence assays evaluated 5-fluorouracil-induced endothelial injury and senescence. Protein expressions were assessed using RT-qPCR and Western blotting. Our results showed that 5-FU-induced endothelial injury and endothelial cell senescence could be improved when treated with ECH in HUVECs. ECH treatment potentially attenuated oxidative stress and ROS production in HUVECs. In addition, the effect of ECH on autophagy markedly reduced the percentage of HUVECs with LC3-II dots and suppressed the Beclin-1 and ATG7 mRNA expression but enhanced the p62 mRNA expression. Besides, ECH treatment significantly increased migrated cells and suppressed the adhesion of THP-1 monocytes in HUVECs. Furthermore, ECH treatment activated the SIRT1 pathway, and its related proteins (SIRT1, p-AMPK and eNOS) expression increased. Nicotinamide (NAM), an inhibitor of SIRT1, significantly attenuated the ECH-induced decrease in the apoptotic rate, increased SA-β-gal-positive cells and significantly reversed the ECH-induced reduction of endothelial senescence. Our results demonstrated that ECH employed endothelial injury and senescence in HUVECs via activation of the SIRT1 pathway.

β-Carboline-α-aminophosphonate Derivative: A Promising Antitumor Agent for Breast Cancer Treatment

Breast cancer is the most common type of cancer and the leading cause of cancer mortality among women worldwide. Considering the limitations of the current treatments available, we analyzed the in vitro cytotoxic potential of ((4-Fluoro-phenyl)-{2-[(1-phenyl-9H-β-carboline-3-carbonyl)-amino]-ethylamino}-methyl)-phosphonic acid dibutyl ester (BCP-1) in breast cancer cells (MCF-7 and MDA-MB-231) and in a non-tumor breast cell line (MCF-10A). BCP-1 has an α-aminophosphonate unit linked to the β-carboline nucleus, and the literature indicates that compounds of these classes have high biological potential. In the present study, the mechanism of action of BCP-1 was investigated through methods of spectrofluorimetry, flow cytometry, and protein expression analysis. It was found that BCP-1 inhibited the proliferation of both cancer cell lines. Furthermore, it induced oxidative stress and cell cycle arrest in G2/M. Upregulation of apoptosis-related proteins such as Bax, cytochrome C, and caspases, as well as a decrease in the anti-apoptotic protein Bcl-2, indicated potential induction of apoptosis in the MDA-MB-231 cells. While in MCF-7 cells, BCP-1 activated the autophagic death pathway, which was demonstrated by an increase in autophagic vacuoles and acidic organelles, in addition to increased expression of LC3I/LC3II and reduced SQSTM1/p62 expression. Further, BCP-1 demonstrated antimetastatic potential by reducing MMP-9 expression and cell migration in both breast cancer cell lines. In conclusion, BCP-1 is a promising candidate for breast cancer chemotherapy.

Advances in the Anti-Tumor Activity of Biflavonoids in Selaginella

Despite the many strategies employed to slow the spread of cancer, the development of new anti-tumor drugs and the minimization of side effects have been major research hotspots in the anti-tumor field. Natural drugs are a huge treasure trove of drug development, and they have been widely used in the clinic as anti-tumor drugs. Selaginella species in the family Selaginellaceae are widely distributed worldwide, and they have been well-documented in clinical practice for the prevention and treatment of cancer. Biflavonoids are the main active ingredients in Selaginella, and they have good biological and anti-tumor activities, which warrant extensive research. The promise of biflavonoids from Selaginella (SFB) in the field of cancer therapy is being realized thanks to new research that offers insights into the multi-targeting therapeutic mechanisms and key signaling pathways. The pharmacological effects of SFB against various cancers in vitro and in vivo are reviewed in this review. In addition, the types and characteristics of biflavonoid structures are described in detail; we also provide a brief summary of the efforts to develop drug delivery systems or combinations to enhance the bioavailability of SFB monomers. In conclusion, SFB species have great potential to be developed as adjuvant or even primary therapeutic agents for cancer, with promising applications.

Balance between autophagy and cell death is maintained by Polycomb-mediated regulation during stem cell differentiation

Autophagy is a conserved cytoprotective process, aberrations in which lead to numerous degenerative disorders. While the cytoplasmic components of autophagy have been extensively studied, the epigenetic regulation of autophagy genes, especially in stem cells, is less understood. Deciphering the epigenetic regulation of autophagy genes becomes increasingly relevant given the therapeutic benefits of small-molecule epigenetic inhibitors in novel treatment modalities. We observe that, during retinoic acid-mediated differentiation of mouse embryonic stem cells (mESCs), autophagy is induced, and identify the Polycomb group histone methyl transferase EZH2 as a regulator of this process. In mESCs, EZH2 represses several autophagy genes, including the autophagy regulator DNA damage-regulated autophagy modulator protein 1 (Dram1). EZH2 facilitates the formation of a bivalent chromatin domain at the Dram1 promoter, allowing gene expression and autophagy induction during differentiation while retaining the repressive H3K27me3 mark. EZH2 inhibition leads to loss of the bivalent domain, with consequent 'hyper-expression' of Dram1, accompanied by extensive cell death. This study shows that Polycomb group proteins help maintain a balance between autophagy and cell death during stem cell differentiation, in part, by regulating the expression of the Dram1 gene.

Qingre Huazhuo Jiangsuan Decoction promotes autophagy by inhibiting PI3K/AKT/mTOR signaling pathway to relieve acute gouty arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Gout belongs to the category of "arthralgia syndrome" in traditional Chinese medicine. It is believed that gout is caused by stagnation of blood stasis, heat, and turbid toxin. Qingre Huazhuo Jiangsuan Decoction (QHJD) is a traditional Chinese medicine prescription developed from the classic Chinese medicine prescription Simiao powder to clear heat, remove turbidity, reduce acid, and reduce inflammation. Now Traditional Chinese Medicine (TCM) physicians often apply it to treat acute gouty arthritis (AGA). However, the mechanism of QHJD in relieving acute gouty arthritis is still unclear, and further research is needed.

AIM OF THE STUDY

Here, we aim to explore the potential mechanism of QHJD in relieving acute gouty arthritis.

MATERIALS AND METHODS

Acute gouty arthritis model was established by injecting monosodium urate (MSU) suspension into knee joint. The pathological state of synovial tissue in each group was evaluated by hematoxylin-eosin (HE) staining. The level of TNF-α, IL-6, and IL-1β were detected by enzyme-linked immunosorbent assay (ELISA). qRT-PCR was used to detect the mRNA expression of NLRP3, ATG5, ATG7, PI3K, AKT, and mTOR. The protein expression of LC3II/I, p62, ULK1, P-ULK1, Beclin-1, PI3K, AKT, mTOR, P-PI3K, P-AKT, and P-mTOR were detected by Western blot.

RESULTS

(1) The level of autophagy protein (mRNA) was significantly up-regulated in QHJD group and rapamycin, while the expression of autophagy protein (mRNA) was significantly downregulated in the 3-methyladenoenoic acid (3 MA) group; (2) QHJD and rapamycin significantly inhibited PI3K/AKT/mTOR pathway, while 3 MA group activated this pathway. (3) It was worth noting that after treatment with QHJD and rapamycin, the inflammatory pathological state of AGA synovial tissue was significantly reduced with the activation of the autophagy gene in knee synovial tissue, and the inhibition of PI3K/AKT/mTOR pathway.

CONCLUSIONS

This research revealed that QHJD activates autophagy by inhibiting PI3K/AKT/mTOR pathway, thereby relieving acute gouty arthritis.

Crosstalk between autophagy and immune cell infiltration in the tumor microenvironment

Autophagy is a conserved process for self-degradation and provides cells with a rescue mechanism to respond to circumstances such as stress and starvation. The role of autophagy in cancer is extremely complex and often paradoxical. Most of the related published studies on tumors are always focused on cancer cells. However, present studies gradually noticed the significance of autophagy in the tumor microenvironment. These studies demonstrate that autophagy and immunity work synergistically to affect tumor progression, indicating that autophagy could become a potential target for cancer immunotherapy. Therefore, it is crucial to clarify the correlation between autophagy and various tumor-infiltrating immune cells in the tumor microenvironment. The context-dependent role of autophagy is critical in the design of therapeutic strategies for cancer.

Inactivation of ZSCAN18 by promoter hypermethylation drives the proliferation via attenuating TP53INP2-mediated autophagy in gastric cancer cells

BACKGROUND

Zinc finger and scan domain containing 18 (ZSCAN18) belongs to the zinc finger transcription factor superfamily, which consists of hundreds of members that play critical roles in all steps of tumorigenesis.

METHODS

This study aims to investigate the roles of ZSCAN18 in gastric cancer (GC). The expression level in GC and the clinicopathologic features of ZSCAN18 were detected by immunohistochemistry staining. Methylation of ZSCAN18 promoter in GC tissues and cell lines was analyzed via MassARRAY; the same method was used to detect GC cell lines demethylated by 5-aza-2'-deoxycytidine treatment. The biological function of ZSCAN18 in GC cells was verified by in vitro and in vivo experiments. The downstream molecular mechanism of ZSCAN18 was explored using RNA next-generation sequencing, immunofluorescence and chromatin immunoprecipitation.

RESULTS

Our work revealed ZSCAN18 expression was markedly reduced in GC tissues compared with adjacent normal tissues as a result of hypermethylation in GC. Likewise, ZSCAN18 expression was significantly reduced in a panel of GC cell lines as a result of the densely methylated ZSCAN18 promoter. Functionally, ZSCAN18 overexpression inhibited the biological progression of GC cells, which was characterized by weaken proliferation, enhanced autophagy and suppressed tumor growth. ZSCAN18 acted as a transcription factor and played an important role in binding to the promoter of tumor protein 53-induced nuclear protein 2 (TP53INP2), and we also confirmed the anti-tumor effect of TP53INP2 in GC. Furthermore, the knockdown of TP53INP2 alleviated the inhibiting effects of ZSCAN18 in GC cells by in vitro and in vivo experiments.

CONCLUSIONS

Collectively, this study unveiled that ZSCAN18 played an anticancer role in GC by promoting autophagy and transcriptional regulation of TP53INP2 and provided a promising target for the diagnosis and treatment of GC.

The epigenetic regulation of cancer cell recovery from therapy exposure and its implications as a novel therapeutic strategy for preventing disease recurrence

The ultimate goal of cancer therapy is the elimination of disease from patients. Most directly, this occurs through therapy-induced cell death. Therapy-induced growth arrest can also be a desirable outcome, if prolonged. Unfortunately, therapy-induced growth arrest is rarely durable and the recovering cell population can contribute to cancer recurrence. Consequently, therapeutic strategies that eliminate residual cancer cells reduce opportunities for recurrence. Recovery can occur through diverse mechanisms including quiescence or diapause, exit from senescence, suppression of apoptosis, cytoprotective autophagy, and reductive divisions resulting from polyploidy. Epigenetic regulation of the genome represents a fundamental regulatory mechanism integral to cancer-specific biology, including the recovery from therapy. Epigenetic pathways are particularly attractive therapeutic targets because they are reversible, without changes in DNA, and are catalyzed by druggable enzymes. Previous use of epigenetic-targeting therapies in combination with cancer therapeutics has not been widely successful because of either unacceptable toxicity or limited efficacy. The use of epigenetic-targeting therapies after a significant interval following initial cancer therapy could potentially reduce the toxicity of combination strategies, and possibly exploit essential epigenetic states following therapy exposure. This review examines the feasibility of targeting epigenetic mechanisms using a sequential approach to eliminate residual therapy-arrested populations, that might possibly prevent recovery and disease recurrence.

Identification and validation of a novel cuproptosis-related gene signature in multiple myeloma

Background: Cuproptosis is a newly identified unique copper-triggered modality of mitochondrial cell death, distinct from known death mechanisms such as necroptosis, pyroptosis, and ferroptosis. Multiple myeloma (MM) is a hematologic neoplasm characterized by the malignant proliferation of plasma cells. In the development of MM, almost all patients undergo a relatively benign course from monoclonal gammopathy of undetermined significance (MGUS) to smoldering myeloma (SMM), which further progresses to active myeloma. However, the prognostic value of cuproptosis in MM remains unknown. Method: In this study, we systematically investigated the genetic variants, expression patterns, and prognostic value of cuproptosis-related genes (CRGs) in MM. CRG scores derived from the prognostic model were used to perform the risk stratification of MM patients. We then explored their differences in clinical characteristics and immune patterns and assessed their value in prognosis prediction and treatment response. Nomograms were also developed to improve predictive accuracy and clinical applicability. Finally, we collected MM cell lines and patient samples to validate marker gene expression by quantitative real-time PCR (qRT-PCR). Results: The evolution from MGUS and SMM to MM was also accompanied by differences in the CRG expression profile. Then, a well-performing cuproptosis-related risk model was developed to predict prognosis in MM and was validated in two external cohorts. The high-risk group exhibited higher clinical risk indicators. Cox regression analyses showed that the model was an independent prognostic predictor in MM. Patients in the high-risk group had significantly lower survival rates than those in the low-risk group (p < 0.001). Meanwhile, CRG scores were significantly correlated with immune infiltration, stemness index and immunotherapy sensitivity. We further revealed the close association between CRG scores and mitochondrial metabolism. Subsequently, the prediction nomogram showed good predictive power and calibration. Finally, the prognostic CRGs were further validated by qRT-PCR in vitro. Conclusion: CRGs were closely related to the immune pattern and self-renewal biology of cancer cells in MM. This prognostic model provided a new perspective for the risk stratification and treatment response prediction of MM patients.

Chrysophanol-Induced Autophagy Disrupts Apoptosis via the PI3K/Akt/mTOR Pathway in Oral Squamous Cell Carcinoma Cells

Background and Objectives: Natural products are necessary sources for drug discovery and have contributed to cancer chemotherapy over the past few decades. Furthermore, substances derived from plants have fewer side effects. Chrysophanol is an anthraquinone derivative that is isolated from rhubarb. Although the anticancer effect of chrysophanol on several cancer cells has been reported, studies on the antitumor effect of chrysophanol on oral squamous-cell carcinoma (OSCC) cells have yet to be elucidated. Therefore, in this study, we investigated the anticancer effect of chrysophanol on OSCC cells (CAL-27 and Ca9-22) via apoptosis and autophagy, among the cell death pathways. Results: It was found that chrysophanol inhibited the growth and viability of CAL-27 and Ca9-22 and induced apoptosis through the intrinsic pathway. It was also found that chrysophanol activates autophagy-related factors (ATG5, beclin-1, and P62/SQSTM1) and LC3B conversion. That is, chrysophanol activated both apoptosis and autophagy. Here, we focused on the roles of chrysophanol-induced apoptosis and the autophagy pathway. When the autophagy inhibitor 3-MA and PI3K/Akt inhibitor were used to inhibit the autophagy induced by chrysophanol, it was confirmed that the rate of apoptosis significantly increased. Therefore, we confirmed that chrysophanol induces apoptosis and autophagy at the same time, and the induced autophagy plays a role in interfering with apoptosis processes. Conclusions: Therefore, the potential of chrysophanol as an excellent anticancer agent in OSCC was confirmed via this study. Furthermore, the combined treatment of drugs that can inhibit chrysophanol-induced autophagy is expected to have a tremendous synergistic effect in overcoming oral cancer.