Autophagy inhibition specifically promotes epithelial-mesenchymal transition and invasion in RAS-mutated cancer cells

Autophagy inhibition amplifies anti-tumor immunity effect of dinutuximab beta on neuroblastoma via the VEGFR/AKT/mTOR and ROS/NF-κB pathways

Dinutuximab beta has shown limited efficacy in treating high-risk neuroblastoma (NB). Combining autophagy inhibitors with immune checkpoint inhibitors (ICIs) has proven effective in many malignancies. However, the anti-tumor effects of autophagy inhibition in conjunction with anti-GD2 immunotherapy remain unknown. In this study, dinutuximab beta induces anti-proliferation and anti-EMT activity in NB cells. Dinutuximab beta also triggers autophagy in NB cells, and inhibition of the VEGFR pathway with anlotinib amplifies dinutuximab beta-induced autophagy. In addition, dinutuximab beta induces the synthesis of the chemokine CXCL9 and the infiltration of CD8+ T cells. Mechanistically, dinutuximab beta inhibits the VEGFR/AKT/mTOR and ROS/NF-κB pathways. Furthermore, autophagy inhibition by CQ enhances CXCL9 expression and anti-tumor T cell responses of single anti-GD2 therapy in vitro and in vivo. Collectively, this study suggests autophagy inhibitors may be a promising strategy for enhancing therapeutic efficacy in NB in conjunction with anti-GD2 immunotherapy.

Sodium-glucose co-transporter 2 (SGLT-2) inhibitors ameliorate renal ischemia-reperfusion injury (IRI) by modulating autophagic processes

Renal ischemia-reperfusion injury (IRI) is a common clinical condition that currently lacks effective treatment options. Inhibitors targeting the sodium-glucose co-transporter-2 (SGLT-2), recognized for their role in managing hyperglycemia, have demonstrated efficacy in enhancing the health outcomes for diabetic patients grappling with chronic kidney disease. Nevertheless, the precise impact of SGLT-2 inhibitors on renal ischemia-reperfusion injury (IRI) and the corresponding transcriptomic alterations remain to be elucidated. In our research, we developed a model of IRI using male C57BL/6 mice by clamping the unilateral renal artery and administering empagliflozin Transcriptomic alterations were analyzed using RNA sequencing (RNA-Seq), complemented by proteomic analysis to investigate the effects of empagliflozin. Histological assessments revealed increased renal inflammatory cell infiltration, widespread renal tubular injury, and elevated autophagosomes formation in the IRI group compared to controls. These pathological changes were significantly attenuated following empagliflozin treatment. Besides, renal function impairment can be alleviated in empagliflozin-treated group. RNA-Seq analysis identified lysosomal autophagy as a key biological process in IRI mice. Empagliflozin exerted a renoprotective effect by downregulating lysosome-associated membrane proteins, primarily LAMP1, LAMP2, and LAMP4 (CD68), through the PI3K-Akt, MAPK, and mTOR signaling pathways, thereby inhibiting autophagic processes. In conclusion, this study highlights enhanced inflammation and disrupted metabolism as hallmark transcriptomic signatures of renal. Furthermore, it demonstrates the renoprotective effects of empagliflozin in alleviating renal IRI by modulating autophagic processes.

KAT2B inhibits proliferation and invasion via inactivating TGF-β/Smad3 pathway-medicated autophagy and EMT in epithelial ovarian cancer

Lysine acetyltransferase 2B (KAT2B) plays a crucial role in epigenetic regulation and tumor pathogenesis. Our study investigates KAT2B's function in epithelial ovarian cancer (EOC) using in vivo and in vitro methods. Immunohistochemistry showed the KAT2B expression in EOC tissues. RNA sequencing (RNA-seq) further identified altered gene expression profiles following KAT2B silencing in EOC cells. Western blot and qRT-PCR were employed to assess the protein and mRNA expression, respectively. KAT2B downregulated in EOC tissues and correlated with both FIGO stage and grade. KAT2B silencing induced autophagy, enhancing cell proliferation and invasion, while overexpression had opposite effects. In vivo, KAT2B silencing increased tumor volume and weight, mitigated by autophagy inhibitor chloroquine. Bioinformatics and co-immunoprecipitation assays identified a KAT2B-SMAD7 interaction. Mechanistic investigations suggested that KAT2B knockdown enhanced autophagy via activation of the TGF-β/Smad3/7 signaling pathway, thereby driving epithelial-mesenchymal transition (EMT), proliferation, and invasion in EOC. Additionally, our data hint at a potential role for the AKT/mTOR pathway. KAT2B acts as a putative tumor suppressor in EOC, where its reduced expression correlates with advanced disease stages. It is implicated in the regulation of autophagy, proliferation, and invasion via the TGF-β/Smad3/7 pathway, positioning KAT2B as a candidate therapeutic target for EOC interventions.

Navigating therapeutic prospects by modulating autophagy in colorectal cancer

Colorectal cancer (CRC) remains a leading cause of death globally despite the improvements in cancer treatment. Autophagy is an evolutionarily conserved lysosomal-dependent degradation pathway that is critical in maintaining cellular homeostasis. However, in cancer, autophagy may have conflicting functions in preventing early tumour formation versus the maintenance of advanced-stage tumours. Defective autophagy has a broad and dynamic effect not just on cancer cells, but also on the tumour microenvironment which influences tumour progression and response to treatment. To add to the layer of complexity, somatic mutations in CRC including tumour protein p53 (TP53), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), Kirsten rat sarcoma viral oncogene homolog (KRAS), and phosphatase and tensin homolog (PTEN) can render chemoresistance by promoting a pro-survival advantage through autophagy. Recent studies have also reported autophagy-related cell deaths that are distinct from classical autophagy by employing parts of the autophagic machinery, which impacts strategies for autophagy regulation in cancer therapy. This review discusses the molecular processes of autophagy in the evolution of CRC and its role in the tumour microenvironment, as well as prospective therapeutic methods based on autophagy suppression or promotion. It also highlights clinical trials using autophagy modulators for treating CRC, underscoring the importance of autophagy regulation in CRC therapy.

MiR-125b-5p alleviates pulmonary fibrosis by inhibiting TGFβ1-mediated epithelial-mesenchymal transition via targeting BAK1

This study explores the role and potential mechanisms of microRNA-125b-5p (miR-125b-5p) in pulmonary fibrosis (PF). PF is a typical outcome of many chronic lung diseases, with poor prognosis and the lack of appropriate medical treatment because PF's molecular mechanisms remain poorly understood. In this study, using in vitro and in vivo analyses, we find that miR-125b-5p is likely a potent regulator of lung fibrosis. The findings reveal that, on the one hand, miR-125b-5p not only specifically decreases in the epithelial-mesenchymal transition (EMT) of lung epithelial cells, but also shows a downregulation trend in the lung tissues of mice with PF. On the other hand, overexpression of miR-125b-5p on the cellular and animal levels downregulates EMT and fibrotic phenotypes, respectively. To clarify the molecular mechanism of the "therapeutic" effect of miR-125b-5p, we use the target prediction tool combined with a dual luciferase assay and complete a rescue experiment by constructing the overexpression vector of the target gene Bcl-2 homologous antagonist/ killer (BAK1), thus confirming that miR-125b-5p can effectively inhibit EMT and fibrosis process by targeting BAK1 gene. MiR-125b-5p inhibits the EMT in lung epithelial cells by negatively regulating BAK1, while overexpression of miR-125b-5p can alleviate lung fibrosis. The findings suggest that MiR-125b-5p/BAK1 can serve as a potential treatment target for PF.

Epigenetic regulation of autophagy by non-coding RNAs and exosomal non-coding RNAs in colorectal cancer: A narrative review

One of the major diseases affecting people globally is colorectal cancer (CRC), which is primarily caused by a lack of effective medical treatment and a limited understanding of its underlying mechanisms. Cellular autophagy functions to break down and eliminate superfluous proteins and substances, thereby facilitating the continual replacement of cellular elements and generating vital energy for cell processes. Non-coding RNAs and exosomal ncRNAs have a crucial impact on regulating gene expression and essential cellular functions such as autophagy, metastasis, and treatment resistance. The latest research has indicated that specific ncRNAs and exosomal ncRNA to influence the process of autophagy in CRC cells, which could have significant consequences for the advancement and treatment of this disease. It has been determined that a variety of ncRNAs have a vital function in regulating the genes essential for the formation and maturation of autophagosomes. Furthermore, it has been confirmed that ncRNAs have a considerable influence on the signaling pathways associated with autophagy, such as those involving AMPK, AKT, and mTOR. Additionally, numerous ncRNAs have the potential to affect specific genes involved in autophagy. This study delves into the control mechanisms of ncRNAs and exosomal ncRNAs and examines how they simultaneously influence autophagy in CRC.

Epidermal Stem Cell Derived Exosomes Alleviate Excessive Autophagy Induced Endothelial Cell Apoptosis by Delivering miR200b-3p to Diabetic Wounds

The dysfunction of endothelial cells caused by hyperglycemia is observed as a decrease in neovascularization in diabetic wound healing. Studies have found that epidermal stem cells (EpiSCs) can promote the angiogenesis of full-thickness wounds. To further explain the therapeutic effect of EpiSCs, EpiSC-derived exosomes (EpiSC-EXOs) are considered the main substance contributing to stem cell effectivity. In our study, EpiSCs and EpiSC-EXOs were supplied to the dorsal wounds of db/db mice. Results showed that EpiSCs could colonize in the wound area and both EpiSCs and EpiSC-EXOs could accelerate diabetic wound healing by promoting angiogenesis. In vitro, persistent high glucose led to the malfunction and apoptosis of endothelial cells. The apoptosis induced by high glucose is due to excessive autophagy and was alleviated by EpiSC-EXOs. RNA sequencing of EpiSC-EXOs showed that miR200b-3p was enriched in EpiSC-EXOs and alleviated the apoptosis of endothelial cells. Synapse defective rho GTPase homolog 1 was identified the target of miR200b-3p and affected the phosphorylation of ERK to regulate intracellular autophagy and apoptosis. Furthermore, animal experiments validated the angiogenic effect of miR200b-3p. Collectively, our results verified the effect of EpiSC-EXOs on apoptosis caused by hyperglycemia in endothelial cells through the miR200b-3p/synapse defective rho GTPase homolog 1 /RAS/ERK/autophagy pathway, providing a theoretical basis for EpiSC in treating diabetic wounds.

LKB1 depletion-mediated epithelial-mesenchymal transition induces fibroblast activation in lung fibrosis

The factors that determine fibrosis progression or normal tissue repair are largely unknown. We previously demonstrated that autophagy inhibition-mediated epithelial-mesenchymal transition (EMT) in human alveolar epithelial type II (ATII) cells augments local myofibroblast differentiation in pulmonary fibrosis by paracrine signalling. Here, we report that liver kinase B1 (LKB1) inactivation in ATII cells inhibits autophagy and induces EMT as a consequence. In IPF lungs, this is caused by downregulation of CAB39L, a key subunit within the LKB1 complex. 3D co-cultures of ATII cells and MRC5 lung fibroblasts coupled with RNA sequencing (RNA-seq) confirmed that paracrine signalling between LKB1-depleted ATII cells and fibroblasts augmented myofibroblast differentiation. Together these data suggest that reduced autophagy caused by LKB1 inhibition can induce EMT in ATII cells and contribute to fibrosis via aberrant epithelial-fibroblast crosstalk.

Thioredoxin (Trx): A redox target and modulator of cellular senescence and aging-related diseases

Thioredoxin (Trx) is a compact redox-regulatory protein that modulates cellular redox state by reducing oxidized proteins. Trx exhibits dual functionality as an antioxidant and a cofactor for diverse enzymes and transcription factors, thereby exerting influence over their activity and function. Trx has emerged as a pivotal biomarker for various diseases, particularly those associated with oxidative stress, inflammation, and aging. Recent clinical investigations have underscored the significance of Trx in disease diagnosis, treatment, and mechanistic elucidation. Despite its paramount importance, the intricate interplay between Trx and cellular senescence-a condition characterized by irreversible growth arrest induced by multiple aging stimuli-remains inadequately understood. In this review, our objective is to present a comprehensive and up-to-date overview of the structure and function of Trx, its involvement in redox signaling pathways and cellular senescence, its association with aging and age-related diseases, as well as its potential as a therapeutic target. Our review aims to elucidate the novel and extensive role of Trx in senescence while highlighting its implications for aging and age-related diseases.

CCL2 promotes metastasis and epithelial-mesenchymal transition of non-small cell lung cancer via PI3K/Akt/mTOR and autophagy pathways

In non-small cell lung cancer (NSCLC), metastasis is the most common phenotype, and autophagy plays a vital role in its regulation. However, there are limited data on how autophagy-related genes and metastasis-related genes affect NSCLC progression. Our goal was to identify the genes that regulate autophagy and metastasis in NSCLC, and to assess the underlying mechanisms in this current study. RNA sequencing data from public databases were used to screen differentially expressed autophagy- and metastasis-associated genes. Enrichment analyses and immune correlations were conducted to identify hub genes and potential regulating pathways in NSCLC. In this study, we found that CCL2 expression was highly expressed in NSCLC tissues and high CCL2 level was correlated with strong infiltration in lung tissues from NSCLC patients. Overexpression of CCL2 can enhance the metastasis of NSCLC cells in nude mice. Furthermore, CCL2 activated the PI3K/Akt/mTOR signalling pathway axis, promoted epithelial-mesenchymal transition (EMT), and blocked the autophagic flux in NSCLC cells. Therefore, our results indicate that CCL2 promotes metastasis and EMT of NSCLC via PI3K/Akt/mTOR axis and autophagy signalling pathways. We believe that CCL2 could be a probable target for the diagnosis and therapeutics of NSCLC, and this study may expand our understanding of lung cancer.

Dysregulated bidirectional epithelial-mesenchymal crosstalk: a core determinant of lung fibrosis progression

Progressive lung fibrosis is characterised by dysregulated extracellular matrix (ECM) homeostasis. Understanding of disease pathogenesis remains limited and has prevented the development of effective treatments. While an abnormal wound healing response is strongly implicated in lung fibrosis initiation, factors that determine why fibrosis progresses rather than regular tissue repair occurs are not fully explained. Within human lung fibrosis there is evidence of altered epithelial and mesenchymal lung populations as well as cells undergoing epithelial-mesenchymal transition (EMT), a dynamic and reversible biological process by which epithelial cells lose their cell polarity and down-regulate cadherin-mediated cell-cell adhesion to gain migratory properties. This review will focus upon the role of EMT and dysregulated epithelial-mesenchymal crosstalk in progressive lung fibrosis.

Contribution of Autophagy to Epithelial Mesenchymal Transition Induction during Cancer Progression

Epithelial Mesenchymal Transition (EMT) is a dedifferentiation process implicated in many physio-pathological conditions including tumor transformation. EMT is regulated by several extracellular mediators and under certain conditions it can be reversible. Autophagy is a conserved catabolic process in which intracellular components such as protein/DNA aggregates and abnormal organelles are degraded in specific lysosomes. In cancer, autophagy plays a controversial role, acting in different conditions as both a tumor suppressor and a tumor-promoting mechanism. Experimental evidence shows that deep interrelations exist between EMT and autophagy-related pathways. Although this interplay has already been analyzed in previous studies, understanding mechanisms and the translational implications of autophagy/EMT need further study. The role of autophagy in EMT is not limited to morphological changes, but activation of autophagy could be important to DNA repair/damage system, cell adhesion molecules, and cell proliferation and differentiation processes. Based on this, both autophagy and EMT and related pathways are now considered as targets for cancer therapy. In this review article, the contribution of autophagy to EMT and progression of cancer is discussed. This article also describes the multiple connections between EMT and autophagy and their implication in cancer treatment.

SQSTM1/p62 promotes the progression of gastric cancer through epithelial-mesenchymal transition

Background

SQSTM1/p62 is an autophagy-related receptor protein that participates in regulating tumorigenesis and multiple signaling pathways. Gastric cancer (GC) is a common tumor in the digestive tract and continues to pose a significant threat to human health. Therefore, this study aims to investigate the impact of p62 on gastric cancer.

Methods

Immunohistochemistry and Western blotting were employed to assess the expression level of the p62 protein in gastric cancer tissues and its correlation with prognosis. Subsequently, in vitro cell experiments were conducted to determine the role of p62 in gastric cancer cell proliferation, migration, and metastasis.

Result

The expression of p62 in gastric cancer tissues was significantly higher than in normal tissues. The expression of p62 was positively correlated with poor prognosis in gastric cancer patients. In vitro cell experiments indicated that p62 promotes gastric cancer cell proliferation and migration. Mechanistically, elevated p62 expression induced epithelial-mesenchymal transition (EMT), leading to upregulation of E-cadherin and downregulation of N-cadherin and vimentin.

Conclusion

This study provides novel and robust evidence for the mechanism by which elevated p62 expression promotes the progression of gastric cancer. It offers promising therapeutic targets for anti-tumor treatment strategies in gastric cancer patients.

PLOD3 facilitated T cell activation in the colorectal tumor microenvironment and liver metastasis by the TNF-α/ NF-κB pathway

BACKGROUND

Colorectal cancer (CRC) has been the third most prevalent cancer worldwide. Liver metastasis is the critical factor for the poor prognosis of CRC. Here, we investigated the expression and role of PLOD3 in CRC.

METHODS

Different liver metastasis models were established by injecting PLOD3 stable knockdown or overexpression CT26 or MC38 mouse CRC cells into the spleen of mice to verify the tumorigenicity and metastasis ability in vivo.

RESULTS

We identified PLOD3 is significantly overexpressed in liver metastasis samples of CRC. High expression of PLOD3 was significantly associated with poor survival of CRC patients. The knockdown of PLOD3 exhibited remarkable inhibition of proliferation, migration, and invasion in CRC cells, while the opposite results could be found in different PLOD3-overexpressed CRC cells. Stable knockdown of PLOD3 also significantly inhibited liver metastasis of CRC cells in different xenografts models, while stable overexpression of PLOD3 promotes liver metastasis and tumor progression. Further studies showed that PLOD3 facilitated the T cell activation in the tumor microenvironment and affected the TNF-α/ NF-κB pathway.

CONCLUSIONS

This study revealed the essential biological functions of PLOD3 in colon cancer progression and metastasis, suggesting that PLOD3 is a promising translational medicine target and bioengineering targeting PLOD3 overcomes CRC liver metastasis.

Paris polyphylla saponins II inhibits invasive, migration and epithelial-mesenchymal transition of melanoma cells through activation of autophagy

Malignant melanoma is a kind of malignant tumor derived from normal epidermal melanocytes or original nevus cells. It has a high degree of malignancy, rapid progress, dangerous condition, and poor prognosis. In recent years, the innovation of traditional Chinese medicine has broadened the scope and effect of tumor treatment. It is a hotspot and breakthrough to find new anti-tumor invasion and migration drugs from natural plants or traditional Chinese medicine. This study explored the role of PPII in promoting autophagy to inhibit EMT of melanoma cells, the role of the PI3K/Akt signaling pathway in the invasion and migration of melanoma cells induced by PPII. We found that PPII effectively inhibited the proliferation, invasion and migration of melanoma B16 and B16F10 in vitro, and induced autophagy. We also established the xenograft tumor and metastatic tumor model of C57BL/6 mice with B16F10 cells. Results showed that PPII effectively inhibited the growth of transplanted tumors, induced autophagy and inhibited the expression level of EMT related protein; Metastasis experiment showed that PPII inhibited the invasion and migration of B16F10, the effect of inhibiting lung metastasis is the most significant. Further mechanism studies showed that the inhibition of PPII on melanoma invasion and migration is related to its induction of autophagy and then inhibition of EMT.

Targeting the RAS/RAF/MAPK pathway for cancer therapy: from mechanism to clinical studies

Metastatic dissemination of solid tumors, a leading cause of cancer-related mortality, underscores the urgent need for enhanced insights into the molecular and cellular mechanisms underlying metastasis, chemoresistance, and the mechanistic backgrounds of individuals whose cancers are prone to migration. The most prevalent signaling cascade governed by multi-kinase inhibitors is the mitogen-activated protein kinase (MAPK) pathway, encompassing the RAS-RAF-MAPK kinase (MEK)-extracellular signal-related kinase (ERK) pathway. RAF kinase is a primary mediator of the MAPK pathway, responsible for the sequential activation of downstream targets, such as MEK and the transcription factor ERK, which control numerous cellular and physiological processes, including organism development, cell cycle control, cell proliferation and differentiation, cell survival, and death. Defects in this signaling cascade are associated with diseases such as cancer. RAF inhibitors (RAFi) combined with MEK blockers represent an FDA-approved therapeutic strategy for numerous RAF-mutant cancers, including melanoma, non-small cell lung carcinoma, and thyroid cancer. However, the development of therapy resistance by cancer cells remains an important barrier. Autophagy, an intracellular lysosome-dependent catabolic recycling process, plays a critical role in the development of RAFi resistance in cancer. Thus, targeting RAF and autophagy could be novel treatment strategies for RAF-mutant cancers. In this review, we delve deeper into the mechanistic insights surrounding RAF kinase signaling in tumorigenesis and RAFi-resistance. Furthermore, we explore and discuss the ongoing development of next-generation RAF inhibitors with enhanced therapeutic profiles. Additionally, this review sheds light on the functional interplay between RAF-targeted therapies and autophagy in cancer.

Unveiling the mechanisms of nephrotoxicity caused by nephrotoxic compounds using toxicological network analysis

Billions of people worldwide have experienced irreversible kidney injuries, which is mainly attributed to the complexity of drug-induced nephrotoxicity. Consequently, there is an urgent need for uncovering the mechanisms of nephrotoxicity caused by compounds. In the present study, a network-based methodology was applied to explore the mechanisms of nephrotoxicity induced by specific compounds. Initially, a total of 42 nephrotoxic compounds and 60 kinds of syndromes associated with nephrotoxicity were collected from public resources. Afterward, network localization and separation algorithms were used to map the targets of compounds and diseases into the human interactome. By doing so, 199 statistically significant nephrotoxic networks displaying the interaction between compound targets and disease genes were obtained, which played pivotal roles in compounds-induced nephrotoxicity. Subsequently, enrichment analysis pinpointed core Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways that highlight commonalities in nephrotoxicity induced by nephrotoxic compounds. It was found that nephrotoxic compounds primarily induce nephrotoxicity by mediating the advanced glycosylation end products-receptor for advanced glycosylation end products signaling pathway in diabetic complications, human cytomegalovirus infection, lipid and atherosclerosis, Kaposi sarcoma-associated herpesvirus infection, apoptosis, and the phosphatidylinositol 3-kinase-Akt pathways. These results provide valuable insights for preventing drug-induced nephrotoxicity. Furthermore, the approaches we used are also helpful in conducting research on other kinds of toxicities.

The Prognosis of Cancer Depends on the Interplay of Autophagy, Apoptosis, and Anoikis within the Tumor Microenvironment

Within the tumor microenvironment, the fight between the immune system and cancer influences tumor transformation. Metastasis formation is an important stage in the progression of cancer. This process is aided by cellular detachment and resistance to anoikis, which are achieved by altering intercellular signaling. Autophagy, specifically pro-survival autophagy, aids cancer cells in developing treatment resistance. Numerous studies have shown that autophagy promotes tumor growth and resistance to anoikis. To regulate protective autophagy, cancer-related genes phosphorylate both pro- and anti-apoptotic proteins. Apoptosis, a type of controlled cell death, eliminates damaged or unwanted cells. Anoikis is a type of programmed cell death in which cells lose contact with the extracellular matrix. The dysregulation of these cellular pathways promotes tumor growth and spread. Apoptosis, anoikis, and autophagy interact meticulously and differently depending on the cellular circumstances. For instance, autophagy can protect cancer cells from apoptosis by removing cellular components that are damaged and might otherwise trigger apoptotic pathways. Similarly, anoikis dysregulation can trigger autophagy by causing cellular harm and metabolic stress. In order to prevent or treat metastatic disease, specifically, targeting these cellular mechanisms may present a promising prospect for cancer therapy. This review discourses the state of our understanding of the molecular and cellular mechanisms underlying tumor transformation and the establishment of metastatic tumors. To enhance the prognosis for cancer, we highlight and discuss potential therapeutic approaches that target these processes and genes involved in them.

Therapeutic strategies targeting AMPK-dependent autophagy in cancer cells

Macroautophagy is a health-modifying process of engulfing misfolded or aggregated proteins or damaged organelles, coating these proteins or organelles into vesicles, fusion of vesicles with lysosomes to form autophagic lysosomes, and degradation of the encapsulated contents. It is also a self-rescue strategy in response to harsh environments and plays an essential role in cancer cells. AMP-activated protein kinase (AMPK) is the central pathway that regulates autophagy initiation and autophagosome formation by phosphorylating targets such as mTORC1 and unc-51 like activating kinase 1 (ULK1). AMPK is an evolutionarily conserved serine/threonine protein kinase that acts as an energy sensor in cells and regulates various metabolic processes, including those involved in cancer. The regulatory network of AMPK is complicated and can be regulated by multiple upstream factors, such as LKB1, AKT, PPAR, SIRT1, or noncoding RNAs. Currently, AMPK is being investigated as a novel target for anticancer therapies based on its role in macroautophagy regulation. Herein, we review the effects of AMPK-dependent autophagy on tumor cell survival and treatment strategies targeting AMPK.

Tight Junction Protein 1 Suppresses Kidney Renal Clear Cell Carcinoma Cells Proliferation by Inducing Autophagy

TJP1, an adaptor protein of the adhesive barrier, has been found to exhibit distinct oncogenic or tumor suppressor functions in a cell-type dependent manner. However, the role of TJP1 in kidney renal clear cell carcinoma (KIRC) remains to be explored. The results showed a marked down-regulation of TJP1 in KIRC tissues compared to normal tissues. Low expression of TJP1 was significantly associated with high grade and poor prognosis in KIRC. Autophagosome aggregation and LC3 II conversion demonstrated that TJP1 may induce autophagy signaling in 786-O and OS-RC-2 cells. Knockdown of TJP1 led to a decrease in the expression of autophagy-related genes, such as BECN1, ATG3, and ATG7. Consistently, TJP1 expression showed a significant positive correlation with these autophagy-related genes in KIRC patients. Furthermore, the overall survival analysis of KIRC patients based on the expression of autophagy-related genes revealed that most of these genes were associated with a good prognosis. TJP1 overexpression significantly suppressed cell proliferation and tumor growth in 786-O cells, whereas the addition of an autophagy inhibitor diminished its inhibitory function. Taken together, these results suggest that TJP1 serves as a favorable prognostic marker and induces autophagy to suppress cell proliferation and tumor growth in KIRC.

Multifaceted role of redox pattern in the tumor immune microenvironment regarding autophagy and apoptosis

The reversible oxidation-reduction homeostasis mechanism functions as a specific signal transduction system, eliciting related physiological responses. Disruptions to redox homeostasis can have negative consequences, including the potential for cancer development and progression, which are closely linked to a series of redox processes, such as adjustment of reactive oxygen species (ROS) levels and species, changes in antioxidant capacity, and differential effects of ROS on downstream cell fate and immune capacity. The tumor microenvironment (TME) exhibits a complex interplay between immunity and regulatory cell death, especially autophagy and apoptosis, which is crucially regulated by ROS. The present study aims to investigate the mechanism by which multi-source ROS affects apoptosis, autophagy, and the anti-tumor immune response in the TME and the mutual crosstalk between these three processes. Given the intricate role of ROS in controlling cell fate and immunity, we will further examine the relationship between traditional cancer therapy and ROS. It is worth noting that we will discuss some potential ROS-related treatment options for further future studies.

The role of epithelial-mesenchymal transition and autophagy in pancreatic ductal adenocarcinoma invasion

Of all pancreatic cancer (PC) cases, approximately 90% are pancreatic ductal adenocarcinoma (PDAC), which progress rapidly due to its high degree of invasiveness and high metastatic potential. Epithelial-mesenchymal transition (EMT) is a prerequisite for cancer cell invasion and spread, and it is mediated by the specific cellular behaviors and the tumor microenvironment. Autophagy has long been a target of cancer therapy, and it has been considered to play a dual and contradictory role, particularly regarding EMT-mediated PDAC invasion. This review discusses the characteristics and the biological role of EMT and autophagy from a cellular perspective, explaining invasion as a survival behavior of PDAC, with the aim of providing novel insights into targeting EMT and autophagy to overcome PDAC invasion.

The new insights into autophagy in thyroid cancer progression

In recent decades, the incidence of thyroid cancer keeps growing at a shocking rate, which has aroused increasing concerns worldwide. Autophagy is a fundamental and ubiquitous biological event conserved in mammals including humans. Basically, autophagy is a catabolic process that cellular components including small molecules and damaged organelles are degraded for recycle to meet the energy needs, especially under the extreme conditions. The dysregulated autophagy has indicated to be involved in thyroid cancer progression. The enhancement of autophagy can lead to autophagic cell death during the degradation while the produced energies can be utilized by the rest of the cancerous tissue, thus this influence could be bidirectional, which plays either a tumor-suppressive or oncogenic role. Accordingly, autophagy can be suppressed by therapeutic agents and is thus regarded as a drug target for thyroid cancer treatments. In the present review, a brief description of autophagy and roles of autophagy in tumor context are given. We have addressed summary of the mechanisms and functions of autophagy in thyroid cancer. Some potential autophagy-targeted treatments are also summarized. The aim of the review is linking autophagy to thyroid cancer, so as to develop novel approaches to better control cancer progression.

Emerging role of autophagy in colorectal cancer: Progress and prospects for clinical intervention

Autophagy is a physiological mechanism in which cells degrade themselves and quickly recover the degraded cell components. Recent studies have shown that autophagy plays an important role in the occurrence, development, treatment, and prognosis of colorectal cancer. In the early stages of colorectal cancer, autophagy can inhibit the production and development of tumors through multiple mechanisms such as maintaining DNA stability, inducing tumor death, and enhancing immune surveillance. However, as colorectal cancer progresses, autophagy may mediate tumor resistance, enhance tumor metabolism, and other pathways to promote tumor development. Therefore, intervening in autophagy at the appropriate time has broad clinical application prospects. This article summarizes the recent research progress of autophagy and colorectal cancer and is expected to provide new theoretical basis and reference for clinical treatment of colorectal cancer.

Mitochondrial division inhibitor (mdivi-1) inhibits proliferation and epithelial-mesenchymal transition via the NF-κB pathway in thyroid cancer cells

Excessively fragmented mitochondria have been reported in thyroid cancer (TC). Mitochondrial division inhibitor (mdivi-1), a putative inhibitor of dynamin-related protein 1 (Drp1), prevents mitochondrial fission and thereby restricts cell proliferation across several types of primary cancer. However, the role of mdivi-1 on TC has not been sufficiently studied. This research is intended to explore the therapeutic effect of mdivi-1 in TC cells. Results demonstrated that highly invasive TC cells displayed excessive mitochondrial fission with more fragmented mitochondria. Treatment with mdivi-1 inhibited mitochondrial fission in 8505C cells as indicated by transmission electron microscope (TEM). It also impaired the proliferation and increased apoptosis in 8505C and K1 cells as shown by plate cloning assay, cell viability assay, and apoptosis assay. Mdivi-1 treatment also attenuated migratory and invasive abilities in 8505C and K1 cells as shown by the transwell assay and the wound healing assay. And we noticed the same inhibition of mdivi-1 in cell migration and cell viability after the knockdown of Drp1 in 8505C cells. This demonstrated that mdivi-1 exerted an anti-tumor effect independently of Drp1 in 8505C cells. Moreover, mdivi-1 treatment reversed epithelial-mesenchymal transition (EMT) by inhibiting the NF-κB pathway in 8505C cells. The present findings demonstrate that mdivi-1 has a therapeutic role in thyroid carcinoma.

TBBPA induced ROS overproduction promotes apoptosis and inflammation by inhibiting autophagy in mice lung

Tetrabromobisphenol A (TBBPA), a non-degradable environmental pollutant, was discharge into the air during the manufacture, use and recycling of plastic products. Respiratory exposure is the main way to inhalation of TBBPA. However, the research on the damage of TBBPA to the respiratory system is still extremely few. The aim of this experiment was to explore the mechanism of TBBPA toxicity to the lungs. Forty C57BL/6 J mice randomly divided into 4 groups, and the experimental groups with TBBPA at 10 n M/kg, 20 n M/kg and 40 n M/kg for 14 consecutive days. Histopathological and ultrastructural analysis showed that the inflammatory cells infiltrated and tissue structure damaged in the lung of mice with exposing to TBBPA. The ROS and MDA levels increase and the T-AOC, GSH-Px, CAT, SOD activities inhibition was found in lung tissue with TBBPA exposure. The expression of autophagy-related factors Beclin-1, P62, LC3-II, ATG5, and ATG7 decreased. The activation of NF-κB/TNF-α pathway indicates the occurrence of inflammation. The expression of Bax, caspase3, caspase7, caspase 9 increase, the expression of Bcl-2 decreased, and the apoptosis pathway activated. The autophagy inducer rapamycin can reverse the adverse effects of inflammation and apoptosis. Taken together, TBBPA inhibits autophagy-induced pneumonia and apoptosis by overproduction ROS.

Electroacupuncture ameliorates surgery-induced spatial memory deficits by promoting mitophagy in rats

Background

This study sought to explore the mechanism underlying the therapeutic effects of electroacupuncture (EA) on spatial memory deficits caused by surgery.

Methods

Hepatic apex resection was performed under propofol-based total intravenous anesthesia. Male Sprague-Dawley rats were subjected to EA treatment or EA + mitochondrial division inhibitor-1 (mdivi-1) treatment once a day for three consecutive days after surgery. The Morris water maze test was used to evaluate the spatial memory of the rats after surgery. Tissue from the hippocampus of each rat was frozen and used for transcriptomic and proteomic analyses to identify potential targets for EA treatment. Western blotting was used to confirm the protein expression levels. The levels of reactive oxygen species (ROS) and adenosine triphosphate (ATP) were detected using commercial kits. The rat mitochondria were then isolated, and the activity of mitochondrial complex V was assessed.

Results

EA attenuated surgery-induced spatial memory deficits on postoperative day 3, while these effects were reversed by treatment with the mdivi-1 (P<0.05). Ribonucleic acid (RNA)-sequencing revealed that EA upregulated multiple metabolic pathways and the phosphatidylinositol 3‑kinas/protein kinase B signaling pathway. The proteomic and western blotting results suggested that the EA treatment substantially downregulated coiled-coil-helix-coiled-coil-helix domain containing 3 (ChChd3) expression in the hippocampus. The EA treatment significantly increased the autophagy-related protein levels, including phosphatase and tensin homolog-induced kinase 1, Parkin, MAP1LC3 (LC3), and Beclin1, and inhibited the production of ROS and inflammatory cytokine interleukin-1β in the hippocampus (P<0.05).

Conclusions

These results suggest that EA ameliorates postoperative spatial memory deficits and protects hippocampus from oxidative stress and inflammation through enhanced autophagy in an animal model of perioperative neurocognitive disorders (PNDs).

Clustering analysis revealed the autophagy classification and potential autophagy regulators' sensitivity of pancreatic cancer based on multi-omics data

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy and is unresponsive to conventional therapeutic modalities due to its high heterogeneity, expounding the necessity, and priority of searching for effective biomarkers and drugs. Autophagy, as an evolutionarily conserved biological process, is upregulated in PDAC and its regulation is linked to a poor prognosis. Increased autophagy sequestered MHC-I on PDAC cells and weaken the antigen presentation and antitumor immune response, indicating the potential therapeutic strategies of autophagy inhibitors.

METHODS

By performing 10 state-of-the-art multi-omics clustering algorithms, we constructed a robust PDAC classification model to reveal the autophagy-related genes among different subgroups.

OUTCOMES

After building a more comprehensive regulating network for potential autophagy regulators exploration, we concluded the top 20 autophagy-related hub genes (GAPDH, MAPK3, RHEB, SQSTM1, EIF2S1, RAB5A, CTSD, MAP1LC3B, RAB7A, RAB11A, FADD, CFKN2A, HSP90AB1, VEGFA, RELA, DDIT3, HSPA5, BCL2L1, BAG3, and ERBB2), six miRNAs, five transcription factors, and five immune infiltrated cells as biomarkers. The drug sensitivity database was screened based on the biomarkers to predict possible drug-targeting signal pathways, hoping to yield novel insights, and promote the progress of the anticancer therapeutic strategy.

CONCLUSION

We succefully constructed an autophagy-related mRNA/miRNA/TF/Immune cells network based on a 10 state-of art algorithm multi-omics analysis, and screened the drug sensitivity dataset for detecting potential signal pathway which might be possible autophagy modulators' targets.

ARFIP2 Regulates EMT and Autophagy in Hepatocellular Carcinoma in Part Through the PI3K/Akt Signalling Pathway

Purpose

ARFIP2, a canonical BAR domain-containing protein, is closely associated with regulating cargo exit from the Golgi. However, the potential biological functions of ARFIP2 in hepatocellular carcinoma (HCC) have not been well investigated. This study aimed to explore the critical role of ARFIP2 in HCC cells.

Methods

The expression of proteins related to epithelial to mesenchymal transition (EMT) and cell autophagy in HCC cells and tissues was assayed by quantitative real-time PCR, Western blotting, immunohistochemistry and immunofluorescence staining. The ability of cells to proliferate, migrate and invade was detected by Cell Counting Kit-8, Transwell migration and invasion assays. In addition, the function of ARFIP2 in vivo was assessed using a tumour xenograft model.

Results

ARFIP2 expression is significantly upregulated in early recurrent and metastatic HCC patients and was positively correlated with a poor prognosis. ARFIP2 overexpression promoted cell proliferation, migration, and invasion by inducing EMT and inhibiting autophagy in vitro. Furthermore, the regulatory effects of ARFIP2 on autophagy and EMT were partially attributed to its regulation of the PI3K/AKT signalling pathway. The in vivo results also showed that ARFIP2 modulates HCC progression.

Conclusion

Our results substantiate a novel mechanism by which ARFIP2 can regulate the activity/phosphorylation of Akt to promote EMT and inhibit autophagy in part via the PI3K/Akt signalling pathway. The ARFIP2/PI3K/Akt axis may be a potential diagnostic biomarker and therapeutic target for HCC.

The interaction between autophagy and the epithelial-mesenchymal transition mediated by NICD/ULK1 is involved in the formation of diabetic cataracts

Background

Cataracts are the leading cause of blindness and a common ocular complication of diabetes. The epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) and altered autophagic activity occur during the development of diabetic cataracts. The disturbed interaction of autophagy with EMT in LECs stimulated by high glucose levels may participate in cataract formation.

Methods

A rat diabetic cataract model induced by streptozotocin (STZ) and human lens epithelial cells (HLE-B3) stimulated with a high glucose concentration were employed in the study. These models were treated with rapamycin (an inhibitor of mammalian target of rapamycin (mTOR)), and N-(N-[3,5-difluorophenacetyl]-1-alanyl)-S-phenylglycine t-butyl ester (DAPT, an inhibitor of γ-secretase) alone or in combination. Lens opacity was observed and photographed under a slit-lamp microscope. Histological changes in paraffin sections of lenses were detected under a light microscope after hematoxylin and eosin staining. Alterations of autophagosomes in LECs were counted and evaluated under a transmission electron microscope. The expression levels of proteins involved in the EMT, autophagy, and the signaling pathways in LECs were measured using Western blotting and immunofluorescence staining. Cell migration was determined by performing transwell and scratch wound assays. Coimmunoprecipitation (Co-IP) was performed to verify protein-protein interactions. Proteins were overexpressed in transfected cells to confirm their roles in the signaling pathways of interest.

Results

In LECs, a high glucose concentration induces the EMT by activating Jagged1/Notch1/Notch intracellular domain (NICD)/Snail signaling and inhibits autophagy through the AKT/mTOR/unc 51-like kinase 1 (ULK1) signaling pathway in vivo and in vitro, resulting in diabetic cataracts. Enhanced autophagic activity induced by rapamycin suppressed the EMT by inducing Notch1 degradation by SQSTM1/p62 and microtubule-associated protein light chain 3 (LC3) in LECs, while inhibition of the Notch signaling pathway with DAPT not only prevented the EMT but also activated autophagy by decreasing the levels of NICD, which bound to ULK1, phosphorylated it, and then inhibited the initiation of autophagy.

Conclusions

We describe a new interaction of autophagy and the EMT involving NICD/ULK1 signaling, which mediates crosstalk between these two important events in the formation of diabetic cataracts. Activating autophagy and suppressing the EMT mutually promote each other, revealing a potential target and strategy for the prevention of diabetic cataracts.

CHRNB2 represses pancreatic cancer migration and invasion via inhibiting β-catenin pathway

Background

Pancreatic cancer is one of the most lethal disease with highly fatal and aggressive properties. Lymph node ratio (LNR), the ratio of the number of metastatic lymph nodes to the total number of examined lymph nodes, is an important index to assess lymphatic metastasis and predict prognosis, but the molecular mechanism underlying high LNR was unclear.

Methods

Gene expression and clinical information data of pancreatic cancer were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Patients in TCGA were averagely divided into low and high LNR groups. Then, Weighted Gene Co-expression Network Analysis (WGCNA) was utilized to build co-expression network to explore LNR-related modules and hub genes. GO and KEGG analysis was performed to find key pathways related to lymph node metastasis. Next, GSE101448 and the overall survival data in TCGA was employed to further select significant genes from hub genes. Considering the key role of CHRNB2 in LNR and survival, gene set enrichment analysis (GSEA) was applied to find pathways related to CHRNB2 expression in pancreatic cancer. The contribution of CHRNB2 to migrative and invasive ability of pancreatic cancer cells was confirmed by Transwell assays. We finally explored the role of CHRNB2 in EMT and β-catenin pathway via Western Blot.

Results

High LNR was significantly related to high T stages and poor prognosis. In WGCNA, 14 hub genes (COL5A1, FN1, THBS2, etc.) were positively related to high LNR, 104 hub genes (FFAR1, SCG5, TMEM63C, etc.) were negatively related to high LNR. After taking the intersection with GSE101448, 13 genes (CDK5R2, SYT7, CACNA2D2, etc.) which might prevent lymph node metastasis were further selected. Among them, CHRNB2 showed the strongest relationship with long survival. Moreover, CHRNB2 also negatively related to the T stages and LNR. Next, knockdown of CHRNB2 expression could acetylcholine (ACh)-independently increase the migration and invasion of pancreatic cancer cells, while CHRNB2 overexpression ACh-independently decrease the migration and invasion of pancreatic cancer cells. For exploring the underlying mechanism, CHRNB2 downregulated β-catenin pathway might through controlling its upstream regulators such as SOX6, SRY, SOX17, and TCF7L2.

Conclusions

CHRNB2 negatively relates to lymph node metastasis in pancreatic cancer patients. CHRNB2 could inhibit β-catenin pathway, EMT, migration and invasion of pancreatic cancer cells via ACh-independent mechanism.

Integrated analysis reveals effects of bioactive ingredients from Limonium Sinense (Girard) Kuntze on hypoxia-inducible factor (HIF) activation

Limonium Sinense (Girard) Kuntze is a traditional Chinese medicinal herb, showing blood replenishment, anti-tumour, anti-hepatitis, and immunomodulation activities amongst others. However, the mechanism of its pharmacological activities remains largely unknown. Here, we investigated the effects of bioactive ingredients from Limonium Sinense using an integrated approach. Water extracts from Limonium Sinense (LSW) showed a strong growth inhibitory effect on multiple cells in both 2D and 3D cultures. Global transcriptomic profiling and further connectivity map (CMap) analysis identified several similarly acting therapeutic candidates, including Tubulin inhibitors and hypoxia-inducible factor (HIF) modulators. The effect of LSW on the cell cycle was verified with flow cytometry showing a G2/M phase arrest. Integrated analysis suggested a role for gallic acid in mediating HIF activation. Taken together, this study provides novel insights into the bioactive ingredients in Limonium Sinense, highlighting the rich natural resource and therapeutic values of herbal plants.

The global research and emerging trends in autophagy of pancreatic cancer: A bibliometric and visualized study

Objective

To present the global research features and hotspots, and forecast the emerging trends by conducting a bibliometric analysis based on literature related to autophagy of pancreatic cancer from 2011 to 2022.

Methods

The literature data regarding autophagy of pancreatic cancer were retrieved and downloaded from the Web of Science Core Collection (WOSCC) from Clarivate Analytics on June 10th, 2022. VOSviewer (version 1.6.18) was used to perform the bibliometric analysis.

Results

A total of 616 studies written by 3993 authors, covered 45 countries and 871 organizations, published in 263 journals and co-cited 28152 references from 2719 journals. China (n=260, 42.2%) and the United States (n=211, 34.3%) were the most frequent publishers and collaborated closely. However, publications from China had a low average number of citations (25.35 times per paper). The output of University of Texas MD Anderson Cancer Center ranked the first with 26 papers (accounting for 4.2% of the total publications). Cancers (n=23, 3.7%; Impact Factor = 6.639) published most papers in this field and was very pleasure to accept related researches. Daolin Tang and Rui Kang published the most papers (n=18, respectively). The research hotspots mainly focused on the mechanisms of autophagy in tumor onset and progression, the role of autophagy in tumor apoptosis, and autophagy-related drugs in treating pancreatic cancer (especially combined therapy). The emerging topics were chemotherapy resistance mediated by autophagy, tumor microenvironment related to autophagy, autophagy-depended epithelial-mesenchymal transition (EMT), mitophagy, and the role of autophagy in tumor invasion.

Conclusion

Attention has been increasing in autophagy of pancreatic cancer over the past 12 years. Our results undoubtedly provide scholars with new clues and ideas in this field.

Autophagy: A Versatile Player in the Progression of Colorectal Cancer and Drug Resistance

Colorectal cancer (CRC) is among the topmost malignancies for both genders. Despite the high incidence rate and advances in diagnostic tools, treatment in many cases is still ineffective. Most cancerous lesions in CRC begin as benign, followed by the development of invasive forms and metastases. The development of CRC has been linked to defects in autophagy, which plays both a pro-and anti-tumor role and is mainly context-dependent. Autophagy suppression could enhance apoptosis via p53 activation, or autophagy also promotes tumor progression by maintaining tumor growth and increasing resistance to chemotherapy. Autophagy promotes the invasion and metastasis of CRC cells via increased epithelial-mesenchymal transition (EMT). Moreover, dysbiosis of gut microbiota upregulated autophagy and metastasis markers. Autophagy responses may also modulate the tumor microenvironment (TME) via regulating the differentiation process of several innate immune cells. Treatments that promote tumor cell death by stimulating or inhibiting autophagy could be beneficial if used as an adjunct treatment, but the precise role of various autophagy-modulating drugs in CRC patients is needed to be explored. In this article, we present an overview of the autophagy process and its role in the pathogenesis and therapeutic resistance of CRC. Also, we focused on the current understanding of the role of the EMT and TME, including its relation to gut microbiota and immune cells, in autophagic manipulation of CRC. We believe that there is a potential link between autophagy, TME, EMT, and drug resistance, suggesting that further studies are needed to explore this aspect.

Emodin inhibits invasion and migration of hepatocellular carcinoma cells via regulating autophagy-mediated degradation of snail and β-catenin

BACKGROUND

Previous studies reported that emodin extracted from Rheum palmatum L. exerts antiproliferation and antimetastatic effects in a variety of human cancer types. However, the role of emodin in hepatocellular carcinoma (HCC) remain unknown.

METHODS

EdU and colony formation assays were performed to evaluate the effects of emodin on proliferation. The mobility capacities of HCC treated with emodin were evaluated using wound healing assay. Transwell invasion and migration assays were performed to evaluate anti-migratory and anti-invasive effects of emodin on HCC. Annexin V-FITC/PI was performed to analyze the apoptosis. PI stain was performed to analyze cell cycle. RNA sequencing technology was used to identify the differentially expressed genes (DEGs) induced by emodin in HCC. The impact of emodin on autophagic flux in HepG2 cells was examined by mCherry-GFP-LC3 analysis. Western blot was used to assess the protein expressions of epithelial-mesenchymal transition (EMT), autophagy, PI3K/AKT/mTOR and Wnt/β-catenin signaling pathway.

RESULTS

We found that emodin inhibited the growth of HepG2 cells in a dose- and time-dependent manner. In addition, emodin inhibited cell proliferation, induced S and G2/M phases arrest, and promoted apoptosis in HepG2 cells. The migration and invasion of HepG2 cells were also suppressed by emodin. Enrichment analysis revealed that DEGs involved in cell adhesion, cancer metastasis and cell cycle arrest. Moreover, western bolt results show that emodin-induced autophagy promotes Snail and β-catenin degradation. We also found that blocking autophagic flux after emodin treatment caused EMT reversal. Furthermore, the PI3K agonist Y-P 740 significantly reversed the phosphorylation levels of GSK3β and mTOR. These results indicated that emodin induced autophagy and inhibited the EMT in part through suppression of the PI3K/AKT/mTOR and Wnt/β-catenin pathways.

CONCLUSION

Our study indicated that emodin inhibited cell metastasis in HCC via the crosstalk between autophagy and EMT.

Interaction between tumor microenvironment, autophagy, and epithelial-mesenchymal transition in tumor progression

Tumor microenvironment (TME) is the ecosystem surrounding a tumor to influence tumor cells' growth, metastasis and immunological battlefield, in which the tumor systems fight against the body system. TME has been considered as the essential link between the tumorigenesis and development of neoplasm. Both nutrients intake and tumor progression to malignancy require the participation of components in TME. Epithelial-mesenchymal transition (EMT) is a key step in the metastasis of tumor cells. Cells that lost polarity and acquired migration ability are prone to metastasize. Autophagy is an important self-protective mechanism in tumor cells and a necessity for the tumor cells to respond to harmful stress. Protective autophagy benefits tumor cells while abnormal autophagy leads to cell injury or death. EMT and autophagy are directly regulated by TME. To date, there are numerous studies on TME, autophagy and EMT separately, but few on their complex interrelationships. This review aims to comprehensively analyze the existing mechanisms and convincing evidence so far to seek novel therapeutic strategies and research directions.

SQSTM1/p62 in intrahepatic cholangiocarcinoma promotes tumor progression via epithelial-mesenchymal transition and mitochondrial function maintenance

BACKGROUND

SQSTM1/p62 is a selective autophagy receptor that regulates multiple signaling pathways participating in the initiation and progression of tumors. Metastasis is still the main cause for intrahepatic cholangiocarcinoma (ICC)-associated mortality. Hence, this study aimed to explore the mechanism of p62 promoting the progression of ICC.

METHODS

Western blotting and immunohistochemical analyses were conducted to detect the expression level of protein p62 in ICC tissues and its correlation with prognosis. Subsequently, the loss-of-function experiments in vitro and in vivo were performed to define the role of p62 in ICC cell proliferation, invasion, and metastasis. Then, the effect of p62 knockdown on mitochondrial function and mitophagy was evaluated by measuring the oxygen consumption rate, and using immunofluorescence and western blotting analyses.

RESULTS

The expression of p62 was significantly upregulated in ICC specimens compared with normal tissues. We further illustrated that p62 expression positively correlated with lymph node metastasis and poor prognosis. The loss-of-function assays revealed that p62 not only promoted ICC cell proliferation, migration, and invasive capacities in vitro, but also induced lung metastasis in the xenograft mouse model. Mechanistically, high expression of p62-induced epithelial-mesenchymal transition (EMT) with the upregulation of Snail, vimentin, N-cadherin, and downregulation of E-cadherin. Moreover, the autophagy-dependent function of p62 might play a vital role in maintaining the mitochondrial function of ICC by mitophagy which might further promote EMT.

CONCLUSION

These data provided new evidence for the mechanism by which abundant p62 expression promoted ICC progression, suggesting a promising therapeutic target for antimetastatic strategies in patients with ICC.

KRT8 Serves as a Novel Biomarker for LUAD and Promotes Metastasis and EMT via NF-κB Signaling

Keratin 8 (KRT8) is the major component of the intermediate filament cytoskeleton and aberrant expression in multiple tumors. However, the role of KRT8 in lung adenocarcinoma (LUAD) remains unclear. In the present study, KRT8 expression was found to be upregulated along with prognosis and metastasis in LUAD. Kaplan-Meier analysis presented that the 5-year OS and DSS rates were significantly better among patients with low KRT8 expression compared to those with high expression. Correlation analysis showed that KRT8 expression was significantly associated with gender (P = 0.027), advanced T stage (P = 0.001), advanced N stage (P = 0.048), and advanced pathologic stage (P = 0.025). Univariate Cox analysis demonstrated that KRT8 was a predictor of OS [hazard ratio (HR) = 1.526; 95% confidence interval (CI) 1.141-2.040; P = 0.004] and DSS (HR = 1.625; 95% CI 1.123-2.353; P = 0.010) in the TCGA database. Importantly, downregulation of KRT8 obviously suppressed cell proliferation, cell migration, invasion, and EMT as well as induced cell apoptosis. KRT8 knockdown significantly inhibited NF-κB signaling, suggesting a potential mechanism. Overall, our results indicated that KRT8 could regulate lung carcinogenesis and may serve as a potential target for antineoplastic therapies.

Autophagy and EMT in cancer and metastasis: Who controls whom?

Metastasis consists of hallmark events, including Epithelial-Mesenchymal Transition (EMT), angiogenesis, initiation of inflammatory tumor microenvironment, and malfunctions in apoptosis. Autophagy is known to play a pivotal role in the metastatic process. Autophagy has pulled researchers towards it in recent times because of its dual role in the maintenance of cancer cells. Evidence states that cells undergoing EMT need autophagy in order to survive during migration and dissemination. Additionally, it orchestrates EMT markers in certain cancers. On the other side of the coin, autophagy plays an oncosuppressive role in impeding early metastasis. This review aims to project the interrelationship between autophagy and EMT. Targeting EMT via autophagy as a useful strategy is discussed in this review. Furthermore, for the first time, we have covered the possible reciprocating roles of EMT and autophagy and its consequences in cancer metastasis.

High expression of p62/SQSTM1 predicts shorter survival for patients with pancreatic cancer

BACKGROUND

Accumulation of the signal adaptor protein p62 has been demonstrated in many forms of cancer, including pancreatic ductal adenocarcinoma (PDAC). Although data from experimental studies suggest that p62 accumulation accelerates the development of PDAC, the association between p62 protein expression and survival in PDAC patients is unclear.

METHODS

Thirty-three tumor specimens from PDAC patients treated by primary surgery were obtained. Immunohistochemical expression of p62, microtubule-associated protein 1A/1B-light chain 3 (LC3), and nuclear factor-erythroid factor 2-related factor 2 (NRF2) in tumor tissue was examined for associations with clinicopathological characteristics and disease-specific survival (DSS).

RESULTS

There was no association between p62 expression and any of the clinicopathological variables. However, high p62 protein expression in tumor cells was significantly associated with shorter DSS (7 months vs. 29 months, p = 0.017). The hazard ratio for death in patients with high p62 protein expression in tumor cells was 2.88 (95% confidence interval: 1.17-7.11, p = 0.022). In multivariable analysis, high p62 expression was an independent prognostic factor for shorter DSS (p = 0.020) when follow up time was more than 5 years. LC3 and NRF2 staining was not associated with survival or other clinicopathological parameters.

CONCLUSION

Our results show that high p62 protein expression in tumor cells is associated with shorter survival following pancreatic tumor resection. This association supports a role for p62 as a prognostic marker in patients with PDAC treated by primary surgery.

CARM1 promotes gastric cancer progression by regulating TFE3 mediated autophagy enhancement through the cytoplasmic AMPK-mTOR and nuclear AMPK-CARM1-TFE3 signaling pathways

BACKGROUND

The role of CARM1 in tumors is inconsistent. It acts as an oncogene in most cancers but it inhibits the progression of liver and pancreatic cancers. CARM1 has recently been reported to regulate autophagy, but this function is also context-dependent. However, the effect of CARM1 on gastric cancer (GC) has not been studied. We aimed to explore whether CARM1 was involved in the progression of GC by regulating autophagy.

METHODS

The clinical values of CARM1 and autophagy in GC were evaluated by immunohistochemistry and qRT-PCR. Transmission electron microscopy, immunofluorescence and western blotting were employed to identify autophagy. The role of CARM1 in GC was investigated by CCK-8, colony formation and flow cytometry assays in vitro and a xenograft model in vivo. Immunoprecipitation assays were performed to determine the interaction of CARM1 and TFE3.

RESULTS

CARM1 was upregulated in clinical GC tissues and cell lines, and higher CARM1 expression predicted worse prognosis. CARM1 enhanced GC cell proliferation, facilitated G1-S transition and inhibited ER stress-induced apoptosis by regulating autophagy. Importantly, treatment with a CARM1 inhibitor rescued the tumor-promoting effects of CARM1 both in vitro and in vivo. Furthermore, we demonstrated that CARM1 promoted TFE3 nuclear translocation to induce autophagy through the cytoplasmic AMPK-mTOR and nuclear AMPK-CARM1-TFE3 signaling pathways.

CONCLUSION

CARM1 promoted GC cell proliferation, accelerated G1-S transition and reduced ER stress-induced apoptosis by regulating autophagy. Mechanistically, CARM1 triggered autophagy by facilitating TFE3 nuclear translocation through the AMPK-mTOR and AMPK-CARM1-TFE3 signaling pathways.

Silica nanoparticles induce pulmonary autophagy dysfunction and epithelial-to-mesenchymal transition via p62/NF-κB signaling pathway

It has been reported that silica nanoparticles (SiNPs) could cause epithelial-to-mesenchymal transition (EMT), but the specific mechanism is still unclear. Thus, the purpose of this study was to investigate the underlying mechanisms of pulmonary EMT after subacute exposure to SiNPs. The results showed intratracheal instillation of SiNPs increased the pulmonary MDA content, while decreased the activity of SOD and GSH-Px in rats. Western blot analysis demonstrated that SiNPs induced autophagy dysfunction via the upregulation of p62. Meanwhile, the inflammation cytokines (TNF-α, IL-18, IL-1β) were released in rat lung. Immunohistochemistry and western blot assays both showed that SiNPs could regulate the related protein biomarkers of EMT through decreasing E-cadherin and increasing vimentin in a dose-dependent manner. Besides, SiNPs activated the proteins expression involved in p62/NF-κB signaling pathway, whereas the pulmonary EMT induced by SiNPs was significantly dampened after the knock down of p62. In this study, we illustrated that subacute exposure to SiNPs could trigger the autophagy dysfunction and pulmonary inflammation, further lead to EMT via activating the p62/NF-κB signaling pathway. Our findings provide new molecular evidence for SiNPs-induced pulmonary toxicity.

A Potential Mechanism of Kidney-Tonifying Herbs Treating Unexplained Recurrent Spontaneous Abortion: Clinical Evidence From the Homogeneity of Embryo Implantation and Tumor Invasion

Background: Kidney-tonifying herbs (KTHs) are widely used to treat unexplained recurrent spontaneous abortion (URSA) based on the theory of traditional Chinese medicine (TCM). However, there is still a lack of systematic evaluation and mechanistic explanation for these treatments.

Objective: The purpose of this study was to assess the clinical efficacy, and to investigate the potential mechanisms, of KTH based on TCM for the treatment of URSA.

Methods: A systematic literature search was conducted within PubMed, Embase, China Biomedical Literature database, Web of Science (WOS), China National Knowledge Infrastructure (CNKI) database, and the Wanfang database to find articles reporting on the Chinese herbal formula based around KTH for treating URSA, which were published between January 2010 and June 2021. A full bibliometric analysis was carried out; in addition, randomized controlled trial (RCT) articles were selected for systematic evaluation and meta-analysis. The drugs with the highest frequency of KTHs were screened for meta-analysis. Finally, network analysis and molecular docking were used to study the key components and potential pathway of KTHs in the treatment of URSA.

Results: The meta-analysis included nine RCTs involving 1,054 subjects. Compared with the control groups, the clinical efficacy of TCM-based KTHs in the treatment of URSA patients significantly improved outcomes. Additionally, a component target pathway network was identified, which included 32 potential blood activating components and 113 main targets. Japonine, sopranol, lysine, and matrine were considered the most important bioactive molecules for KTHs. The key potential therapeutic pathway for URSA was a tumor-related signaling pathway. The target genes for URSA regulated by KTHs were highly similar to tumor biological processes such as the regulation of apoptotic signaling pathways, inflammatory responses, angiogenesis, and epithelial metabolic transition.

Conclusion: KTH has great potential for treating URSA. Because the maintenance of pregnancy has a high similarity with tumor invasion, the research relating to tumor mechanisms should also be followed up as it may lead to new ideas and breakthroughs for research into URSA. At the same time, embryonic and decidual cells share a high degree of cellular heterogeneity and spatial structural complexity with tumor cells, and a single cell combined with spatial omics may be the best future approach for validating KTH mechanisms.

Autophagy Contributes to Metabolic Reprogramming and Therapeutic Resistance in Pancreatic Tumors

Metabolic reprogramming is a feature of cancers for which recent research has been particularly active, providing numerous insights into the mechanisms involved. It occurs across the entire cancer process, from development to resistance to therapies. Established tumors exhibit dependencies for metabolic pathways, constituting vulnerabilities that can be targeted in the clinic. This knowledge is of particular importance for cancers that are refractory to any therapeutic approach, such as Pancreatic Ductal Adenocarcinoma (PDAC). One of the metabolic pathways dysregulated in PDAC is autophagy, a survival process that feeds the tumor with recycled intracellular components, through both cell-autonomous (in tumor cells) and nonautonomous (from the local and distant environment) mechanisms. Autophagy is elevated in established PDAC tumors, contributing to aberrant proliferation and growth even in a nutrient-poor context. Critical elements link autophagy to PDAC including genetic alterations, mitochondrial metabolism, the tumor microenvironment (TME), and the immune system. Moreover, high autophagic activity in PDAC is markedly related to resistance to current therapies. In this context, combining autophagy inhibition with standard chemotherapy, and/or drugs targeting other vulnerabilities such as metabolic pathways or the immune response, is an ongoing clinical strategy for which there is still much to do through translational and multidisciplinary research.

The new horizon of biomarker in melanoma patients: A study based on autophagy-related long non-coding RNA

Autophagy-related long non-coding RNAs (arlncRNAs) play a crucial role in the pathogenesis and development of the tumor. However, there is a lack of systematic analysis of arlncRNAs in melanoma patients.Melanoma data for analysis were obtained from The Cancer Genome Atlas (TCGA) database. By establishing a co-expression network of autophagy-related mRNAs-lncRNAs, we identified arlncRNAs in melanoma patients. We evaluated the prognostic value of arlncRNAs by univariate and multivariate Cox analysis and constructed an arlncRNAs risk model. Patients were divided into high- and low-risk groups based on the arlncRNAs risk score. This model was evaluated by Kaplan-Meier (K-M) analysis, univariate-multivariate Cox regression analysis, and receiver operating characteristic (ROC) curve analysis. Characteristics of autophagy genes and co-expressive tendency were analyzed by principal component analysis and Gene Set Enrichment Analysis (GSEA) functional annotation.Nine arlncRNAs (USP30-AS1, LINC00665, PCED1B-AS1, LINC00324, LINC01871, ZEB1-AS1, LINC01527, AC018553.1, and HLA-DQB1-AS1) were identified to be related to the prognosis of melanoma patients. Otherwise, the 9 arlncRNAs constituted an arlncRNAs prognostic risk model. K-M analysis and ROC curve analysis showed that the arlncRNAs risk model has good discrimination. Univariate and multivariate Cox regression analysis showed that arlncRNAs risk model was an independent prognostic factor in melanoma patients. Principal component analysis and GSEA functional annotation showed different autophagy and carcinogenic status in the high- and low-risk groups.This novel arlncRNAs risk model plays an essential role in predicting of the prognosis of melanoma patients. The model reveals new prognosis-related biomarkers for autophagy, promotes precision medicine, and provides a lurking target for melanoma's autophagy-related treatment.

The Role of Autophagy in Childhood Central Nervous System Tumors

OPINION STATEMENT

Autophagy is a physiological process that occurs in normal tissues. Under external environmental pressure or internal environmental changes, cells can digest part of their contents through autophagy in order to reduce metabolic pressure or remove damaged organelles. In cancer, autophagy plays a paradoxical role, acting as a tumor suppressor-by removing damaged organelles and inhibiting inflammation or by promoting genome stability and the tumor-adaptive responses-as a pro-survival mechanism to protect cells from stress. In this article, we review the autophagy-dependent mechanisms driving childhood central nervous system tumor cell death, malignancy invasion, chemosensitivity, and radiosensitivity. Autophagy inhibitors and inducers have been developed, and encouraging results have been achieved in autophagy modulation, suggesting that these might be potential therapeutic agents for the treatment of pediatric central nervous system (CNS) tumors.

The Autophagic Route of E-Cadherin and Cell Adhesion Molecules in Cancer Progression

Simple Summary

A hallmark of carcinoma progression is the loss of epithelial integrity. In this context, the deregulation of adhesion molecules, such as E-cadherin, affects epithelial structures and associates with epithelial to mesenchymal transition (EMT). This, in turn, fosters cancer progression. Autophagy endows cancer cells with the ability to overcome intracellular and environmental stress stimuli, such as anoikis, nutrient deprivation, hypoxia, and drugs. Furthermore, it plays an important role in the degradation of cell adhesion proteins and in EMT. This review focuses on the interplay between the turnover of adhesion molecules, primarily E-cadherin, and autophagy in cancer progression.

Abstract

Cell-to-cell adhesion is a key element in epithelial tissue integrity and homeostasis during embryogenesis, response to damage, and differentiation. Loss of cell adhesion and gain of mesenchymal features, a phenomenon known as epithelial to mesenchymal transition (EMT), are essential steps in cancer progression. Interestingly, downregulation or degradation by endocytosis of epithelial adhesion molecules (e.g., E-cadherin) associates with EMT and promotes cell migration. Autophagy is a physiological intracellular degradation and recycling process. In cancer, it is thought to exert a tumor suppressive role in the early phases of cell transformation but, once cells have gained a fully transformed phenotype, autophagy may fuel malignant progression by promoting EMT and conferring drug resistance. In this review, we discuss the crosstalk between autophagy, EMT, and turnover of epithelial cell adhesion molecules, with particular attention to E-cadherin.

Increased ATG5 Expression Predicts Poor Prognosis and Promotes EMT in Cervical Carcinoma

Cervical cancer has the second-highest incidence and mortality of female malignancy. The major causes of mortality in patients with cervical cancer are invasion and metastasis. The epithelial–mesenchymal transition (EMT) process plays a major role in the acquisition of metastatic potential and motility. Autophagy-related genes (ARGs) are implicated in the EMT process, and autophagy exerts a dual function in EMT management at different phases of tumor progression. However, the role of specific ARGs during the EMT process has not yet been reported in cervical cancer. Based on the data from the Cancer Genome Atlas (TCGA) cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) sequencing database, we performed the prognosis analysis for those ARGs obtained from the Human Autophagy database. ATG5 was identified as the only important harmful marker influencing survival of cervical cancer patients by univariate Cox regression (HR 1.7; 95% CI: 1.0–2.8, p = 0.047), and the 5-years survival rate for the high- and low-ATG5 expression groups was 0.486 (0.375–0.631) and 0.782 (0.708–0.863), respectively. TCGA CESC methylation data showed that eight methylation sites of ATG5 could also be significantly associated with the overall survival (OS) of cervical cancer patients. Single-sample gene-set enrichment and gene functional enrichment results showed that ATG5 was correlated with some cancer-related pathways, such as phagocytosis-related genes, endocytosis-related genes, immune-related genes, EMT score, and some EMT signature-related genes. Next, cell migration and invasion assay and Western blot were applied to detect the function of ATG5 in EMT of cervical cancer. In cervical cancer cells, ATG5 knockdown resulted in attenuation of migration and invasion. The functional study showed that knockdown of ATG5 could reverse EMT process by P-ERK, P-NFκBp65, P-mTOR pathways, and so on. In conclusion, the present study implies that ATG5 was a major contributor to EMT regulation and poor prognosis in cervical cancer.

SPOCK1 promotes metastasis in pancreatic cancer via NF-κB-dependent epithelial-mesenchymal transition by interacting with IκB-α

BACKGROUND

Sparc/osteonectin, cwcv and kazal-like domain proteoglycan 1 (SPOCK1) has been reported to function as an oncogene in a variety of cancer types. Increasing evidence suggests that SPOCK1 contributes to the metastatic cascade, including invasion, epithelial-mesenchymal transition (EMT) and micro-metastasis formation. As yet, however, the underlying mechanism is not clearly understood. Here, we evaluated the expression and clinicopathological significance of SPOCK1 in primary pancreatic cancer (PC) specimens and explored the mechanisms underlying SPOCK1-mediated PC cell growth and metastasis.

METHODS

The clinical relevance of SPOCK1 was evaluated in 81 patients with PC. The effect of SPOCK1 on proliferation, cell cycle progression, EMT and metastasis was examined in vitro and in vivo. The molecular mechanisms involved in SPOCK1-mediated regulation of NF-κB-dependent EMT were assessed in PC cell lines.

RESULTS

We found that SPOCK1 expression was increased in PC tissues and was associated with lymph node metastasis. Silencing or exogenous overexpression of SPOCK1 markedly altered the proliferation of PC cells through cell cycle transition. Overexpression of SPOCK1 promoted PC cell migration and invasion by regulating EMT progression. Moreover, we found that SPOCK1 contributes to EMT and metastasis by activating the NF-κB signalling pathway via direct interaction with IκBα. After NF-κB pathway inhibition by BAY11-7082, we found that PC cell motility and EMT induced by SPOCK1 were reversed.

CONCLUSION

From our data we conclude that SPOCK1 promotes PC metastasis via NF-κB-dependent EMT by interacting with IκBα. This newly identified mechanism may provide novel clues for the (targeted) treatment of PC patients.