Autophagy Paradox of Cancer: Role, Regulation, and Duality

Autophagy and nutrigenomics: a winning team against chronic disease and tumors

Autophagy, a vital cell process, has garnered attention for its role in various diseases and potential therapeutic interventions. Dysregulation of autophagy contributes to conditions such as metabolic diseases, neurodegenerative disorders, and cancer. In diseases such as diabetes, autophagy plays a crucial role in islet β-cell maintenance and glucose homeostasis, offering potential targets for therapeutic intervention. Nutrigenomics, which explores how dietary components interact with the genome, has emerged as a promising avenue for disease management. It sheds light on how diet influences gene expression and cellular processes, offering personalized approaches to disease prevention and management. Studies have showed the impact of specific dietary components, such as polyphenols and omega-3 fatty acids, on autophagy processes, suggesting their potential therapeutic benefits in neurodegenerative conditions and metabolic disorders. In cancer, autophagy's dual role in either suppressing tumorigenesis or promoting cancer cell survival underscores the importance of understanding its modulation through dietary interventions. Combined with conventional chemotherapy drugs, dietary compounds show synergistic effects in cancer treatment. Furthermore, phytochemicals such as indicaxanthin have been found to epigenetically regulate genes involved in autophagy, offering novel insights into personalized cancer therapies. This comprehensive review has the aim to study the autophagy in a combined view with nutrigenomics effects of some dietary molecules in maintaining cellular homeostasis and responding to pathological stimuli. Overall, the intersection of autophagy and nutrigenomics effect of bioactive compounds holds promise for developing targeted interventions for various diseases, emphasizing the significance of dietary interventions in disease prevention and management.

The Emerging Role of Long Noncoding RNAs in Sorafenib Resistance Within Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), a liver cancer originating from hepatocytes, is a major health concern and among the most common malignancies worldwide. Sorafenib, approved by the U.S. F.D.A., is the primary first-line treatment for patients with advanced HCC. While the preferred first-line systemic regimen for HCC is immunotherapy with Atezolizumab plus bevacizumab or Tremelimumab-actl + durvalumab, Sorafenib is still an alternative recommended regimen. While some patients with advanced HCC may benefit from Sorafenib treatment, most eventually develop resistance, leading to poor prognosis. Long noncoding RNAs (lncRNAs) have been found to play a critical role in tumorigenesis and the development of HCC, as well as other cancers. They are also key players in tumor drug resistance, though the mechanisms of lncRNAs in Sorafenib resistance in HCC remain poorly understood. This review summarizes the molecular mechanisms contributing to Sorafenib resistance in HCC with their potential correlation with lncRNAs, including the roles of transporters, receptors, cell death regulation, and other influencing factors.

Modulatory Effects of Regulated Cell Death: An Innovative Preventive Approach for the Control of Mastitis

Mastitis is a common disease worldwide that affects the development of the dairy industry due to its high incidence and complex etiology. Precise regulation of cell death and survival plays a critical role in maintaining internal homeostasis, organ development, and immune function in organisms, and regulatory abnormalities are a common mechanism of various pathological changes. Recent research has shown that regulated cell death (RCD) plays a crucial role in mastitis. The development of drugs to treat cell death and survival abnormalities that can be widely used in mastitis treatment has important clinical significance. This paper will review the molecular mechanisms of apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis and their regulatory roles in mastitis to provide a new perspective for the targeted treatment of mastitis.

MicroRNA-582-5p inhibits the progression of gastric cancer cells and their resistance to oxaliplatin by suppressing ATG7 expression

Background

Gastric cancer (GC) is one of the most common malignant tumors of the digestive tract worldwide. Both environmental and genetic factors contribute to the occurrence and development of GC. Surgery and chemotherapy are the main treatment modalities for gastric cancer; however, some patients show insensitivity to chemotherapeutic agents. Chemotherapy resistance is one of the primary reasons for poor treatment outcomes and the high likelihood of recurrence and metastasis in gastric cancer patients. Numerous studies have confirmed a correlation between the dysregulation of microRNA expression and the development of various malignant tumors, as well as their resistance to chemotherapeutic agents. However, the role of microRNA-582-3p in gastric cancer cells and its mechanism in the resistance of gastric cancer cells to oxaliplatin have not been studied.

Methods

We first used q-PCR, CCK8, transwell, and scratch assays to validate the expression of microRNA-582-3p in gastric cancer tissues and cells, while also analyzing the relationship between its expression levels and the clinical pathological data of patients. Additionally, we further confirmed the impact of microRNA-582-3p on gastric cancer cell progression and oxaliplatin resistance through knockdown and overexpression experiments. Subsequently, to explore the specific mechanisms of microRNA-582-3p in gastric cancer, we verified the downstream target of microRNA-582-3p, ATG7, using dual-luciferase reporter assays and examined the effect of ATG7 on gastric cancer cell functions. Moreover, we conducted rescue experiments to further validate the interaction between microRNA-582-3p and ATG7.

Results

Our experimental results confirmed that microRNA-582-3p is lowly expressed in gastric cancer tissues and cells, and the expression level of miR-582-5p is correlated with the T stage of patients, while showing no correlation with the patients' gender, age, tumor size, degree of differentiation, or N stage. Additionally, we found that microRNA-582-3p functions as a tumor suppressor in gastric cancer cells, as its overexpression inhibits the biological functions of gastric cancer cells and increases their sensitivity to oxaliplatin. Furthermore, we identified binding sites between microRNA-582-3p and the autophagy-related gene ATG7, observing that knockdown of microRNA-582-3p increases ATG7 expression, while its overexpression reduces ATG7 levels. Moreover, ATG7 is overexpressed in gastric cancer cells; knockdown of ATG7 inhibits the biological functions of gastric cancer cells and increases their sensitivity to oxaliplatin, whereas overexpression of ATG7 reverses the inhibitory effect of miR-582-5p on gastric cancer.

Conclusion

Our study confirms that microRNA-582-3p acts as a tumor suppressor in gastric cancer cells, and its role may be mediated through the regulation of ATG7 expression levels. MicroRNA-582-3p may serve as a potential target for gastric cancer treatment and a predictive biomarker.

Targeting autophagy can synergize the efficacy of immune checkpoint inhibitors against therapeutic resistance: New promising strategy to reinvigorate cancer therapy

Immune checkpoints are a set of inhibitory and stimulatory molecules/mechanisms that affect the activity of immune cells to maintain the existing balance between pro- and anti-inflammatory signaling pathways and avoid the progression of autoimmune disorders. Tumor cells can employ these checkpoints to evade immune system. The discovery and development of immune checkpoint inhibitors (ICIs) was thereby a milestone in the area of immuno-oncology. ICIs stimulate anti-tumor immune responses primarily by disrupting co-inhibitory signaling mechanisms and accelerate immune-mediated killing of tumor cells. Despite the beneficial effects of ICIs, they sometimes encounter some degrees of therapeutic resistance, and thereby do not effectively act against tumors. Among multiple combination therapies have been introduced to date, targeting autophagy, as a cellular degradative process to remove expired organelles and subcellular constituents, has represented with potential capacities to overcome ICI-related therapy resistance. It has experimentally been illuminated that autophagy induction blocks the immune checkpoint molecules when administered in conjugation with ICIs, suggesting that autophagy activation may restrict therapeutic challenges that ICIs have encountered with. However, the autophagy flux can also provoke the immune escape of tumors, which must be considered. Since the conventional FDA-approved ICIs have designed and developed to target programmed cell death receptor/ligand 1 (PD-1/PD-L1) as well as cytotoxic T lymphocyte-associated molecule 4 (CTLA-4) immune checkpoint molecules, we aim to review the effects of autophagy targeting in combination with anti-PD-1/PD-L1- and anti-CTLA-4-based ICIs on cancer therapeutic resistance and tumor immune evasion.

ZFP1 is a biomarker related to poor prognosis and immunity in gastric cancer

We aimed to determine the prognostic significance of ZFP1 in gastric cancer (GC), its role in the immune microenvironment, and its potential as a therapeutic target using data from The Cancer Genome Atlas (TCGA) database. ZFP1 overexpression was closely associated with tumour T stage and histological grade. Patients with GC and high ZFP1 expression had poor outcomes. Lower ZFP1 expression was associated with longer symptom-free intervals and disease-specific survival. Subgroup analyses of T3 and T4, N0, N1, and M0 patients showed that overall survival (OS), disease-specific survival, and progression-free interval (PFI) were worse in those with high ZFP1 expression. ZFP1 expression in GC was moderately to strongly positively correlated with the infiltration levels of effector central memory T cells and T helper cells and negatively correlated with Th17 cells and NK CD56bright cells. The lncRNA-miRNA-ZFP1 axis was predicted using a public database. CCK8, colony formation, and wound healing assays were conducted to investigate whether ZFP1 promoted the proliferation and migration of GC cells. Our study suggests that ZFP1 plays a key role in the prognosis, immune response, and progression of GC and is a significant factor in the diagnosis and treatment of this disease.

Cell death pathways: molecular mechanisms and therapeutic targets for cancer

Cell death regulation is essential for tissue homeostasis and its dysregulation often underlies cancer development. Understanding the different pathways of cell death can provide novel therapeutic strategies for battling cancer. This review explores several key cell death mechanisms of apoptosis, necroptosis, autophagic cell death, ferroptosis, and pyroptosis. The research gap addressed involves a thorough analysis of how these cell death pathways can be precisely targeted for cancer therapy, considering tumor heterogeneity and adaptation. It delves into genetic and epigenetic factors and signaling cascades like the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathways, which are critical for the regulation of cell death. Additionally, the interaction of the microenvironment with tumor cells, and particularly the influence of hypoxia, nutrient deprivation, and immune cellular interactions, are explored. Emphasizing therapeutic strategies, this review highlights emerging modulators and inducers such as B cell lymphoma 2 (BCL2) homology domain 3 (BH3) mimetics, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), chloroquine, and innovative approaches to induce ferroptosis and pyroptosis. This review provides insights into cancer therapy's future direction, focusing on multifaceted approaches to influence cell death pathways and circumvent drug resistance. This examination of evolving strategies underlines the considerable clinical potential and the continuous necessity for in-depth exploration within this scientific domain.

Immunohistochemical Profile of p62/SQSTM1/Sequestosome-1 in Human Low- and High-Grade Intracranial Meningiomas

Among autophagic-related proteins, p62/SQSTM1/Sequestosome-1 represents a relevant actor in cellular proliferation and neoplastic growth. Although, recently, p62 expression has been analyzed in different neurodegenerative and glial neoplastic diseases, no available information have been reported in meningiomas, which have an high epidemiological relevance being the second most common category of intracranial tumors after gliomas. Generally meningiomas have a benign behavior, but their recurrence is not uncommon mainly when atypical or anaplastic varieties occur. However, intranuclear vacuoles have been ultrastructurally observed in meningiomas, and they were labelled by p62 antibodies. Therefore, in the present study, we have investigated p62 immunohistochemical pattern in a cohort of 133 cases representative of low- and high-grade meningiomas, to verify if p62 expression may be related to clinicopathological data, thus achieving a potential prognostic role. The p62 immunoexpression was frequently found in the nucleus and cytoplasm of neoplastic elements, and utilizing an intensity-distribution score, 55 (41.3%) cases were considered as high expressors while 78 (58.7%) cases were instead recorded as low expressors. Fifteen cases exhibited recurrences of the disease, 14 of which were codified as high expressors. Moreover, a direct relationship between p62 and Mib-1 immunoexpression as well as between p62 and neoplastic grade have been documented. Finally, we suggest that impaired autophagic flux with an increase in p62 expression may be involved in the activation of NRF2 also contributing in the development of recurrence in meningioma patients.

Prospects of compounds of herbal plants as anticancer agents: a comprehensive review from molecular pathways

Cancer refers to the proliferation and multiplication of aberrant cells inside the human body, characterized by their capacity to proliferate and infiltrate various anatomical regions. Numerous biochemical pathways and signaling molecules have an impact on the cancer auto biogenesis process. The regulation of crucial cellular processes necessary for cell survival and proliferation, which are triggered by phytochemicals, is significantly influenced by signaling pathways. These pathways or components are regulated by phytochemicals. Medicinal plants are a significant reservoir of diverse anticancer medications employed in chemotherapy. The anticancer effects of phytochemicals are mediated by several methods, including induction of apoptosis, cessation of the cell cycle, inhibition of kinases, and prevention of carcinogenic substances. This paper analyzes the phytochemistry of seven prominent plant constituents, namely, alkaloids, tannins, flavonoids, phenols, steroids, terpenoids, and saponins, focusing on the involvement of the MAPK/ERK pathway, TNF signaling, death receptors, p53, p38, and actin dynamics. Hence, this review has examined a range of phytochemicals, encompassing their structural characteristics and potential anticancer mechanisms. It has underscored the significance of plant-derived bioactive compounds in the prevention of cancer, utilizing diverse molecular pathways. In addition, this endeavor also seeks to incentivize scientists to carry out clinical trials on anticancer medications derived from plants.

Oxidative Stress in Breast Cancer: A Biochemical Map of Reactive Oxygen Species Production

This review systematizes information about the metabolic features of breast cancer directly related to oxidative stress. It has been shown those redox changes occur at all levels and affect many regulatory systems in the human body. The features of the biochemical processes occurring in breast cancer are described, ranging from nonspecific, at first glance, and strictly biochemical to hormone-induced reactions, genetic and epigenetic regulation, which allows for a broader and deeper understanding of the principles of oncogenesis, as well as maintaining the viability of cancer cells in the mammary gland. Specific pathways of the activation of oxidative stress have been studied as a response to the overproduction of stress hormones and estrogens, and specific ways to reduce its negative impact have been described. The diversity of participants that trigger redox reactions from different sides is considered more fully: glycolytic activity in breast cancer, and the nature of consumption of amino acids and metals. The role of metals in oxidative stress is discussed in detail. They can act as both co-factors and direct participants in oxidative stress, since they are either a trigger mechanism for lipid peroxidation or capable of activating signaling pathways that affect tumorigenesis. Special attention has been paid to the genetic and epigenetic regulation of breast tumors. A complex cascade of mechanisms of epigenetic regulation is explained, which made it possible to reconsider the existing opinion about the triggers and pathways for launching the oncological process, the survival of cancer cells and their ability to localize.

FHL2 promotes the aggressiveness of lung adenocarcinoma by inhibiting autophagy via activation of the PI3K/AKT/mTOR pathway

BACKGROUND

Increasing evidence indicates that four and a half LIM domains 2 (FHL2) plays a crucial role in the progression of various cancers. However, the biological functions and molecular mechanism of FHL2 in lung adenocarcinoma (LUAD) remain unclear.

METHODS

We evaluated the prognostic value of FHL2 in LUAD using public datasets and further confirmed its prognostic value with our clinical data. The biological functions of FHL2 in LUAD were evaluated by in vitro and in vivo experiments. Pathway analysis and rescue experiments were subsequently performed to explore the molecular mechanism by which FHL2 promoted the progression of LUAD.

RESULTS

FHL2 was upregulated in LUAD tissues compared to adjacent normal lung tissues, and FHL2 overexpression was correlated with unfavorable outcomes in patients with LUAD. FHL2 knockdown significantly suppressed the proliferation, migration and invasion of LUAD cells, while FHL2 overexpression had the opposite effect. Mechanistically, FHL2 upregulated the PI3K/AKT/mTOR pathway and subsequently inhibited autophagy in LUAD cells. The effects FHL2 on the proliferation, migration and invasion of LUAD cells are dependent on the inhibition of autophagy, as of induction autophagy attenuated the aggressive phenotype induced by FHL2 overexpression.

CONCLUSIONS

FHL2 promotes the progression of LUAD by activating the PI3K/AKT/mTOR pathway and subsequently inhibiting autophagy, which can be exploited as a potential therapeutic target for LUAD.

Autophagy: a necessary evil in cancer and inflammation

Autophagy, a highly regulated cellular process, assumes a dual role in the context of cancer. On the one hand, it functions as a crucial homeostatic pathway, responsible for degrading malfunctioning molecules and organelles, thereby maintaining cellular health. On the other hand, its involvement in cancer development and regression is multifaceted, contingent upon a myriad of factors. This review meticulously examines the intricacies of autophagy, from its molecular machinery orchestrated by Autophagy-Related Genes (ATG) initially discovered in yeast to the various modes of autophagy operative within cells. Beyond its foundational role in cellular maintenance, autophagy reveals context-specific functions in processes like angiogenesis and inflammation. Our analysis delves into how autophagy-related factors directly impact inflammation, underscoring their profound implications for cancer dynamics. Additionally, we extend our inquiry to explore autophagy's associations with cardiovascular conditions, neurodegenerative disorders, and autoimmune diseases, illuminating the broader medical relevance of this process. Furthermore, this review elucidates how autophagy contributes to sustaining hallmark cancer features, including stem cell maintenance, proliferation, angiogenesis, metastasis, and metabolic reprogramming. Autophagy emerges as a pivotal process that necessitates careful consideration in cancer treatment strategies. To this end, we investigate innovative approaches, ranging from enzyme-based therapies to MTOR inhibitors, lysosomal blockers, and nanoparticle-enabled interventions, all aimed at optimizing cancer treatment outcomes by targeting autophagy pathways. In summary, this comprehensive review provides a nuanced perspective on the intricate and context-dependent role of autophagy in cancer biology. Our exploration not only deepens our understanding of this fundamental process but also highlights its potential as a therapeutic target. By unraveling the complex interplay between autophagy and cancer, we pave the way for more precise and effective cancer treatments, promising better outcomes for patients.

The dual role of autophagy in the regulation of cancer treatment

As a catabolic process, autophagy through lysosomes degrades defective and damaged cellular materials to support homeostasis in stressful conditions. Therefore, autophagy dysregulation is associated with the induction of several human pathologies, including cancer. Although the role of autophagy in cancer progression has been extensively studied, many issues need to be addressed. The available evidence suggest that autophagy shows both cytoprotective and cytotoxic mechanisms. This dual role of autophagy in cancer has supplied a renewed interest in the development of novel and effective cancer therapies. Considering this, a deeper understanding of the molecular mechanisms of autophagy in cancer treatment is crucial. This article provides a summary of the recent advances regarding the dual and different mechanisms of autophagy-mediated therapeutic efficacy in cancer.

Synthetic lethality in human bladder cancer cells by curcumin via concurrent Aurora A inhibition and autophagy induction

Combination therapies to induce mixed-type cell death and synthetic lethality have the potential to overcome drug resistance in cancer. In this study, we demonstrated that the curcumin-enhanced cytotoxicity of cisplatin/carboplatin in combination with gemcitabine was associated with Aurora A suppression-mediated G2/M arrest, and thus apoptosis, as well as MEK/ERK-mediated autophagy in human bladder cancer cells. Animal study data confirmed that curcumin combined with cisplatin/gemcitabine reduced tumorigenesis of xenograft in mice and this phenomenon was associated with elevated expressions of p-ERK and reduced p-Aurora A in tumors. Gene analyses using data repositories further revealed that reduced Aurora A expression alone did not significantly elevate the sensitivity of human bladder carcinoma cells to these anticancer drugs. Unlike other major cancer types, human bladder urothelial carcinoma tissue coexpressed higher AURKA and lower MAP1LC3B than normal tissue, and reduced Aurora A and induction of autophagy have been clinically associated with a better prognosis in patients with early but not advanced stage bladder cancer. Therefore, our results suggest that treatment strategies can utilize the synthetic lethal pair to concurrently suppress oncogenic Aurora A and induce autophagy by coadministrating curcumin with anticancer drugs for early-stage bladder cancer with high expression of Aurora A.

Inhibition of Autophagy and the Cytoprotective Role of Smac Mimetic against ROS-Induced Cancer: A Potential Therapeutic Strategy in Relapse and Chemoresistance Cases in Breast Cancer

With more than a million deaths each year, breast cancer is the top cause of death in women. Around 70% of breast cancers are hormonally responsive. Although several therapeutic options exist, cancer resistance and recurrence render them inefficient and insufficient. The major key reason behind this is the failure in the regulation of the cell death mechanism. In addition, ROS was also found to play a major role in this problem. The therapeutic benefits of Smac mimetic compound (SMC) BV6 on MCF7 were examined in the current study. Treatment with BV6 reduces viability and induces apoptosis in MCF7 breast cancer cells. BV6 suppresses autophagy and has demonstrated a defensive role in cancer cells against oxidative stress caused by H₂O₂. Overall, the present investigation shows that SMC has therapeutic and cytoprotective potential against oxidative stress in cancer cells. These Smac mimetic compounds may be used as anti-cancer drugs as well as antioxidants alone or in conjunction with other commonly used antioxidants.

The relationship between autophagy and PD-L1 and their role in antitumor therapy

Immune checkpoint blockade therapy is an important advance in cancer treatment, and the representative drugs (PD-1/PD-L1 antibodies) have greatly improved clinical outcomes in various human cancers. However, since many patients still experience primary resistance, they do not respond to anti-PD1/PD-L1 therapy, and some responders also develop acquired resistance after an initial response. Therefore, combined therapy with anti-PD-1/PD-L1 immunotherapy may result in better efficacy than monotherapy. In tumorigenesis and tumor development processes, the mutual regulation of autophagy and tumor immune escape is an intrinsic factor of malignant tumor progression. Understanding the correlation between the tumor autophagy pathway and tumor immune escape may help identify new clinical cancer treatment strategies. Since both autophagy and immune escape of tumor cells occur in a relatively complex microenvironmental network, autophagy affects the immune-mediated killing of tumor cells and immune escape. Therefore, comprehensive treatment targeting autophagy and immune escape to achieve “immune normalization” may be an important direction for future research and development. The PD-1/PD-L1 pathway is essential in tumor immunotherapy. High expression of PD-L1 in different tumors is closely related to poor survival rates, prognoses, and treatment effects. Therefore, exploring the mechanism of PD-L1 expression is crucial to improve the efficacy of tumor immunotherapy. Here, we summarize the mechanism and mutual relationship between autophagy and PD-L1 in antitumor therapy, which may help enhance current antitumor immunotherapy approaches.

Kinetics of autophagic activity in nanoparticle-exposed lung adenocarcinoma (A549) cells

Autophagy, a homeostatic mechanism, is crucial in maintaining normal cellular function. Although dysregulation of autophagic processes is recognized in certain diseases, it is unknown how maintenance of cellular homeostasis might be affected by the kinetics of autophagic activity in response to various stimuli. In this study, we assessed those kinetics in lung adenocarcinoma (A549) cells in response to exposure to nanoparticles (NP) and/or Rapamycin. Since NP are known to induce autophagy, we wished to determine if this phenomenon could be a driver of the harmful effects seen in lung tissues exposed to air pollution. A549 cells were loaded with a fluorescent marker (DAPRed) that labels autophagosomes and autolysosomes. Autophagic activity was assessed based on the fluorescence intensity of DAPRed measured over the entire cell volume of live single cells using confocal laser scanning microscopy (CLSM). Autophagic activity over time was determined during exposure of A549 cells to single agents (50 nM Rapamycin; 80 μg/mL, 20 nm carboxylated polystyrene NP (PNP); or, 1 μg/mL ambient ultrafine particles (UFP) (<180 nm)), or double agents (Rapamycin + PNP or Rapamycin + UFP; concomitant and sequential), known to stimulate autophagy. Autophagic activity increased in all experimental modalities, including both single agent and double agent exposures, and reached a steady state in all cases ~2 times control from ~8 to 24 hrs, suggesting the presence of an upper limit to autophagic capacity. These results are consistent with the hypothesis that environmental stressors might exert their harmful effects, at least in part, by limiting available autophagic response to additional stimulation, thereby making nanoparticle-exposed cells more susceptible to secondary injury due to autophagic overload.

Roles of hypoxia-inducible factor in hepatocellular carcinoma under local ablation therapies

Hepatocellular carcinoma (HCC) is one of the most common digestive malignancies. HCC It ranges as the fifth most common cause of cancer mortality worldwide. While The prognosis of metastatic or advanced HCC is still quite poor. Recently, locoregional treatment, especially local ablation therapies, plays an important role in the treatment of HCC. Radiofrequency ablation (RFA) and high-intensity focused ultrasound (HIFU) ablation are the most common-used methods effective and feasible for treating HCC. However, the molecular mechanisms underlying the actions of ablation in the treatments for HCC and the HCC recurrence after ablation still are poorly understood. Hypoxia-inducible factor (HIF), the key gene switch for adaptive responses to hypoxia, has been found to play an essential role in the rapid aggressive recurrence of HCC after ablation treatment. In this review, we summarized the current evidence of the roles of HIF in the treatment of HCC with ablation. Fifteen relevant studies were included and further analyzed. Among them, three clinical studies suggested that HIF-1α might serve as a crucial role in the RAF treatment of HCC or the local recurrence of HCC after RFA. The remainder included experimental studies demonstrated that HIF-1, 2α might target the different molecules (e.g., BNIP3, CA-IX, and arginase-1) and signaling cascades (e.g., VEGFA/EphA2 pathway), constituting a complex network that promoted HCC invasion and metastasis after ablation. Currently, the inhibitors of HIF have been developed, providing important proof of targeting HIF for the prevention of HCC recurrence after IRFA and HIFU ablation. Further confirmation by prospective clinical and in-depth experimental studies is still warranted to illustrate the effects of HIF in HCC recurrence followed ablation treatment in the future.

Targeting Class I-II-III PI3Ks in Cancer Therapy: Recent Advances in Tumor Biology and Preclinical Research

Phosphatidylinositol-3-kinase (PI3K) enzymes, producing signaling phosphoinositides at plasma and intracellular membranes, are key in intracellular signaling and vesicular trafficking pathways. PI3K is a family of eight enzymes divided into three classes with various functions in physiology and largely deregulated in cancer. Here, we will review the recent evidence obtained during the last 5 years on the roles of PI3K class I, II and III isoforms in tumor biology and on the anti-tumoral action of PI3K inhibitors in preclinical cancer models. The dependency of tumors to PI3K isoforms is dictated by both genetics and context (e.g., the microenvironment). The understanding of class II/III isoforms in cancer development and progression remains scarce. Nonetheless, the limited available data are consistent and reveal that there is an interdependency between the pathways controlled by all PI3K class members in their role to promote cancer cell proliferation, survival, growth, migration and metabolism. It is unknown whether this feature contributes to partial treatment failure with isoform-selective PI3K inhibitors. Hence, a better understanding of class II/III functions to efficiently inhibit their positive and negative interactions with class I PI3Ks is needed. This research will provide the proof-of-concept to develop combination treatment strategies targeting several PI3K isoforms simultaneously.

Cannabidiol regulates apoptosis and autophagy in inflammation and cancer: A review

Cannabidiol (CBD) is a terpenoid naturally found in plants. The purified compound is used in the treatment of mental disorders because of its antidepressive, anxiolytic, and antiepileptic effects. CBD can affect the regulation of several pathophysiologic processes, including autophagy, cytokine secretion, apoptosis, and innate and adaptive immune responses. However, several authors have reported contradictory findings concerning the magnitude and direction of CBD-mediated effects. For example, CBD treatment can increase, decrease, or have no significant effect on autophagy and apoptosis. These variable results can be attributed to the differences in the biological models, cell types, and CBD concentration used in these studies. This review focuses on the mechanism of regulation of autophagy and apoptosis in inflammatory response and cancer by CBD. Further, we broadly elaborated on the prospects of using CBD as an anti-inflammatory agent and in cancer therapy in the future.

Emerging degrader technologies engaging lysosomal pathways

Targeted protein degradation (TPD) provides unprecedented opportunities for drug discovery. While the proteolysis-targeting chimera (PROTAC) technology has already entered clinical trials and changed the landscape of small-molecule drugs, new degrader technologies harnessing alternative degradation machineries, especially lysosomal pathways, have emerged and broadened the spectrum of degradable targets. We have recently proposed the concept of autophagy-tethering compounds (ATTECs) that hijack the autophagy protein microtubule-associated protein 1A/1B light chain 3 (LC3) for targeted degradation. Other groups also reported degrader technologies engaging lysosomal pathways through different mechanisms including AUTACs, AUTOTACs, LYTACs and MoDE-As. In this review, we analyse and discuss ATTECs along with other lysosomal-relevant degrader technologies. Finally, we will briefly summarize the current status of these degrader technologies and envision possible future studies.

SMAC Mimetic BV6 Co-Treatment Downregulates the Factors Involved in Resistance and Relapse of Cancer: IAPs and Autophagy

Cancer is the utmost common disease-causing death worldwide, characterized by uncontrollable cell division with the potential of metastasis. Overexpression of the Inhibitors of Apoptosis proteins (IAPs) and autophagy correlates with tumorigenesis, therapeutic resistance, and reoccurrence after anticancer therapies. This study illuminates the role and efficacy of smac mimetic compound BV6 alone and in co-treatment with death ligands such as TRAIL and TNFα in the regulation of cell death mechanisms, i.e., apoptosis and autophagy. In this study, MTT assays, wound healing assays, and cellular and nuclear morphological studies were done. DAPI staining, AO/EtBr staining and AnnexinV/PI FACS was done to study the apoptosis. The expression of IAPs and autophagy biomarkers was analyzed using Real time-PCR and western blotting. Meanwhile, TEM demonstrated autophagy and cellular autophagic vacuoles in response to the BV6. The result shows a promising anti-cancer effect of BV6 alone as well as in combinational treatment with TRAIL and TNFα, compared to the lone treatment of TRAIL and TNFα in both breast cancer cell lines. The smac mimetic compound might provide an alternative combinational therapy with conventional anticancer therapies to tackle their inefficiency at the advanced stage of cancer, cancer resistance, and reoccurrence. Also, IAPs and autophagic proteins could act as potent target molecules for the development of novel anti-cancer drugs in pathogenesis and the betterment of regimens for cancer.

Immunoexpression of p62/SQSTM1/Sequestosome‑1 in human primary and recurrent IDH1/2 wild‑type glioblastoma: A pilot study

p62/SQSTM1/Sequestosome-1 is an autophagic protein that serves a crucial role in cellular metabolism, proliferation and malignant growth. Notably, autophagy may influence the development and resistance to therapy of numerous types of human cancer. In the present pilot study, the immunohistochemical pattern of p62 was analyzed in a cohort of patients with isocitrate dehydrogenase (IDH)1/2 wild-type glioblastoma (GBM), in primary and recurrent samples, in order to verify the concordance or discordance between the primary and recurrent tumors. In addition, the association between p62, and patient outcome and O⁶-methylguanine-DNA methyltransferase (MGMT) status was assessed. The results revealed p62 immunoexpression in the nucleus and cytoplasm of neoplastic elements in 45% of primary and 55% of recurrent cases of GBM. A discordant p62 immunoreactivity was detected in 35% of cases, with a variation either with positive or negative conversion of p62 status. Statistically, p62 expression and MGMT status exhibited a significant prognostic value by univariate analysis, whereas only MGMT promoter methylation status emerged as an independent prognostic factor by multivariate analysis. Finally, the most favorable prognosis was documented when the same GBM case was positively concordant for both p62 expression and MGMT methylated status. Since little data are available regarding the association between p62 expression and MGMT in GBM, further investigations may be required to determine if new targeted therapies may be addressed against autophagy-related proteins, such as p62.

The autophagy inducer trehalose stimulates macropinocytosis in NF1-deficient glioblastoma cells

Background

Glioblastoma is a highly aggressive brain tumor. A big effort is required to find novel molecules which can cross the blood–brain barrier and efficiently kill these tumor cells. In this perspective, trehalose (α-glucopyranosyl‐[1→1]‐α‐d‐glucopyranoside), found in various dietary sources and used as a safe nutrient supplement, attracted our attention for its pleiotropic effects against tumor cells.

Methods

Human glioblastoma cell lines U373-MG and T98G were exposed to trehalose and analyzed at different time points. Cell proliferation was evaluated at medium term, and clonogenic capacity and cell morphology were evaluated at long term. Western blot was used to evaluate biochemical markers of autophagy (also measured in cells co-treated with EIPA or chloroquine), and mTOR, AMPK and ERK 1/2 signalling. Macropinocytosis was evaluated morphologically by bright-field microscopy; in cells loaded with the fluorescein-conjugated fluid-phase tracer dextran, macropinocytic vacuoles were also visualized by fluorescence microscopy, and the extent of macropinocytosis was quantified by flow cytometry.

Results

The long-term effect of trehalose on U373-MG and T98G cell lines was impressive, as indicated by a dramatic reduction in clonogenic efficiency. Mechanistically, trehalose proved to be an efficient autophagy inducer in macropinocytosis-deficient T98G cells and an efficient inducer of macropinocytosis and eventual cell death by methuosis in U373-MG glioblastoma cells, proved to be poorly responsive to induction of autophagy. These two processes appeared to act in a mutually exclusive manner; indeed, co-treatment of U373-MG cells with the macropinocytosis inhibitor, EIPA, significantly increased the autophagic response. mTOR activation and AMPK inhibition occurred in a similar way in the two trehalose-treated cell lines. Interestingly, ERK 1/2 was activated only in macropinocytosis-proficient U373-MG cells harbouring loss-of-function mutations in the negative RAS regulator, NF1, suggesting a key role of RAS signalling.

Conclusions

Our results indicate that trehalose is worthy of further study as a candidate molecule for glioblastoma therapy, due to its capacity to induce a sustained autophagic response, ultimately leading to loss of clonogenic potential, and more interestingly, to force macropinocytosis, eventually leading to cell death by methuosis, particularly in tumor cells with RAS hyperactivity. As a further anticancer strategy, stimulation of macropinocytosis may be exploited to increase intracellular delivery of anticancer drugs.

Therapeutic potential of autophagy activators and inhibitors in lung and breast cancer- a review

Autophagy is a cellular process that eliminates damaged components of cytoplasm via the lysosome. Autophagy supports cells and tissues to remain healthy by recycling old or damaged cellular organelles and proteins with new ones. The breakdown products that follow are directed into cellular metabolism, where they are utilized to produce energy as well as for maintaining homeostasis and stability of the genome. In many cancers, autophagy modulation carries out a dual role in cancer development and suppression. Autophagy suppresses the proliferation of cancer cells by bringing about cell death and limiting cancer cell development, although it also promotes tumorigenesis by encouraging cancer cell growth and formation. Nevertheless, autophagy's implication in cancer remains a paradox. While several autophagy activators, and inhibitors, such as SAH-EJ2, Gefitinib, Ampelopsin hydroxychloroquine and chloroquine, are utilized to regulate autophagy in chemoprevention, the exact intrinsic system of autophagy in cancer deserves further investigation. Despite improved treatment regimens, the incidence rate of both breast and lung cancer has grown, as has the number of recurrence cases. Hence, this review offers a wide overview of autophagy's underlying role in lung and breast cancer, particularly focusing on the various autophagy activators and inhibitors in both cancers, as well as the use of various organic compounds, regular drugs, and natural products in cancer prevention and treatment.

l-Asparaginase synergizes with etoposide via the PI3K/Akt/mTOR pathway in Epstein-Barr virus-positive Burkitt lymphoma

Burkitt lymphoma (BL) is an aggressive Epstein-Barr virus (EBV)-driven B-cell lymphoma characterized by the translocation and rearrangement of the c-Myc proto-oncogene. High-intensity multidrug chemotherapy regimens have a limited effect on the survival of refractory or relapsed BL patients, mainly owing to the high EBV load and drug resistance. l-asparaginase ( l-Asp) and etoposide (VP-16) play a beneficial role in EBV-related lymphoproliferative diseases; however, their roles and mechanisms in BL remain unclear. In this study, we found that VP-16 inhibited BL cell proliferation and arrested the cell cycle at the G₂ /M phase. It also induced autophagy and activated the extrinsic and intrinsic apoptotic signaling pathways in BL cells. Mechanistically, VP-16 inhibited c-Myc expression and regulated the PI3K/Akt/mTOR signaling pathway. Notably, VP-16 also showed a specific synergistic effect with l-Asp to induce apoptosis in EBV-positive BL cells but not in EBV-negative BL cells. VP-16 combined with l-Asp further inhibited c-Myc expression and downregulated the PI3K/Akt/mTOR signaling pathway. Additionally, we found that VP-16 inhibited the expression of latent membrane protein 1 (LMP1), and in combination with l-Asp further decreased LMP1 expression in Raji cells. Our in vivo data also showed that the dual-drug combination significantly inhibited the growth of BL tumors and prolonged the survival of mice compared to VP-16 alone. In conclusion, this study provides new evidence that l-Asp may enhance the antitumor effect of VP-16 by inhibiting the PI3K/Akt/mTOR signaling pathway in EBV-positive BL cells.

Novel Therapeutic Strategies for Ischemic Stroke: Recent Insights into Autophagy

Stroke is one of the leading causes of death and disability worldwide. Autophagy is a conserved cellular catabolic pathway that maintains cellular homeostasis by removal of damaged proteins and organelles, which is critical for the maintenance of energy and function homeostasis of cells. Accumulating evidence demonstrates that autophagy plays important roles in pathophysiological mechanisms under ischemic stroke. Previous investigations show that autophagy serves as a “double-edged sword” in ischemic stroke as it can either promote the survival of neuronal cells or induce cell death in special conditions. Following ischemic stroke, autophagy is activated or inhibited in several cell types in brain, including neurons, astrocytes, and microglia, as well as microvascular endothelial cells, which involves in inflammatory activation, modulation of microglial phenotypes, and blood-brain barrier permeability. However, the exact mechanisms of underlying the role of autophagy in ischemic stroke are not fully understood. This review focuses on the recent advances regarding potential molecular mechanisms of autophagy in different cell types. The focus is also on discussing the “double-edged sword” effect of autophagy in ischemic stroke and its possible underlying mechanisms. In addition, potential therapeutic strategies for ischemic stroke targeting autophagy are also reviewed.

Robustness of the Autophagy Pathway to Somatic Copy Number Losses

Autophagy allows cells to temporarily tolerate energy stress by replenishing critical metabolites through self-digestion, thereby attenuating the cytotoxic effects of anticancer drugs that target tumor metabolism. Autophagy defects could therefore mark a metabolically vulnerable cancer state and open a therapeutic window. While mutations of autophagy genes (ATGs) are notably rare in cancer, haploinsufficiency network analyses across many cancers have shown that the autophagy pathway is frequently hit by somatic copy number losses of ATGs such as MAP1LC3B/ATG8F (LC3), BECN1/ATG6 (Beclin-1), and ATG10. Here, we used CRISPR/Cas9 technology to delete increasing numbers of copies of one or more of these ATGs in non-small cell lung cancer cells and examined the effects on sensitivity to compounds targeting aerobic glycolysis, a hallmark of cancer metabolism. Whereas the complete knockout of one ATG blocked autophagy and led to profound metabolic vulnerability, this was not the case for combinations of different nonhomozygous deletions. In cancer patients, the effect of ATG copy number loss was blunted at the protein level and did not lead to the accumulation of p62 as a sign of reduced autophagic flux. Thus, the autophagy pathway is shown to be markedly robust and resilient, even with the concomitant copy number loss of key autophagy genes.

Non-Coding RNAs in Tuberculosis Epidemiology: Platforms and Approaches for Investigating the Genome's Dark Matter

A growing amount of information about the different types, functions, and roles played by non-coding RNAs (ncRNAs) is becoming available, as more and more research is done. ncRNAs have been identified as potential therapeutic targets in the treatment of tuberculosis (TB), because they may be essential regulators of the gene network. ncRNA profiling and sequencing has recently revealed significant dysregulation in tuberculosis, primarily due to aberrant processes of ncRNA synthesis, including amplification, deletion, improper epigenetic regulation, or abnormal transcription. Despite the fact that ncRNAs may have a role in TB characteristics, the detailed mechanisms behind these occurrences are still unknown. The dark matter of the genome can only be explored through the development of cutting-edge bioinformatics and molecular technologies. In this review, ncRNAs' synthesis and functions are discussed in detail, with an emphasis on the potential role of ncRNAs in tuberculosis. We also focus on current platforms, experimental strategies, and computational analyses to explore ncRNAs in TB. Finally, a viewpoint is presented on the key challenges and novel techniques for the future and for a wide-ranging therapeutic application of ncRNAs.

p53 Modulation of Autophagy Signaling in Cancer Therapies: Perspectives Mechanism and Therapeutic Targets

The key tumor suppressor protein p53, additionally known as p53, represents an attractive target for the development and management of anti-cancer therapies. p53 has been implicated as a tumor suppressor protein that has multiple aspects of biological function comprising energy metabolism, cell cycle arrest, apoptosis, growth and differentiation, senescence, oxidative stress, angiogenesis, and cancer biology. Autophagy, a cellular self-defense system, is an evolutionarily conserved catabolic process involved in various physiological processes that maintain cellular homeostasis. Numerous studies have found that p53 modulates autophagy, although the relationship between p53 and autophagy is relatively complex and not well understood. Recently, several experimental studies have been reported that p53 can act both an inhibitor and an activator of autophagy which depend on its cellular localization as well as its mode of action. Emerging evidences have been suggested that the dual role of p53 which suppresses and stimulates autophagy in various cencer cells. It has been found that p53 suppression and activation are important to modulate autophagy for tumor promotion and cancer treatment. On the other hand, activation of autophagy by p53 has been recommended as a protective function of p53. Therefore, elucidation of the new functions of p53 and autophagy could contribute to the development of novel therapeutic approaches in cancer biology. However, the underlying molecular mechanisms of p53 and autophagy shows reciprocal functional interaction that is a major importance for cancer treatment and manegement. Additionally, several synthetic drugs and phytochemicals have been targeted to modulate p53 signaling via regulation of autophagy pathway in cancer cells. This review emphasizes the current perspectives and the role of p53 as the main regulator of autophagy-mediated novel therapeutic approaches against cancer treatment and managements.

The Apoptosis Paradox in Cancer

Cancer growth represents a dysregulated imbalance between cell gain and cell loss, where the rate of proliferating mutant tumour cells exceeds the rate of those that die. Apoptosis, the most renowned form of programmed cell death, operates as a key physiological mechanism that limits cell population expansion, either to maintain tissue homeostasis or to remove potentially harmful cells, such as those that have sustained DNA damage. Paradoxically, high-grade cancers are generally associated with high constitutive levels of apoptosis. In cancer, cell-autonomous apoptosis constitutes a common tumour suppressor mechanism, a property which is exploited in cancer therapy. By contrast, limited apoptosis in the tumour-cell population also has the potential to promote cell survival and resistance to therapy by conditioning the tumour microenvironment (TME)-including phagocytes and viable tumour cells-and engendering pro-oncogenic effects. Notably, the constitutive apoptosis-mediated activation of cells of the innate immune system can help orchestrate a pro-oncogenic TME and may also effect evasion of cancer treatment. Here, we present an overview of the implications of cell death programmes in tumour biology, with particular focus on apoptosis as a process with "double-edged" consequences: on the one hand, being tumour suppressive through deletion of malignant or pre-malignant cells, while, on the other, being tumour progressive through stimulation of reparatory and regenerative responses in the TME.

A Balance Between Autophagy and Other Cell Death Modalities in Cancer

Autophagy is an intracellular self-digestive process involved in catabolic degradation of damaged proteins, and organelles, and the elimination of cellular pathogens. Initially, autophagy was considered as a prosurvival mechanism, but the following insights shed light on its prodeath function. Nowadays, autophagy is established as a crucial player in the development of various diseases through interaction with other molecular pathways within a cell. Additionally, disturbance in autophagy is one of the main pathological alterations that lead to resistance of cancer cells to treatment. These autophagy-related pathologies gave rise to the development of new therapeutic drugs. Here, we summarize the current knowledge on the autophagic role in disease pathogenesis, particularly in cancer, and the interplay between autophagy and other cell death modalities in order to combat cancer.

Calorie Restriction for Cancer Prevention and Therapy: Mechanisms, Expectations, and Efficacy

Cancer is one of the most frequently diagnosed diseases, and despite the continuous efforts in searching for new and more effective treatments, its morbidity and mortality remain a significant health problem worldwide. Calorie restriction, a dietary manipulation that consists in a reduction of the calorie intake, is gaining attention as a potential adjuvant intervention for preventing and/or fighting cancer. Several forms of energy reduction intake, which includes caloric restriction tout-court, dietary restrictions, and intermittent fasting, are being explored for their ability to prevent or slow down cancer progression. Additionally, another anti-cancer approach being under investigation relies on the use of nutraceuticals known as “Caloric Restriction Mimetics” that can provide caloric restriction-mediated benefits without subjecting the patients to a strict diet. Preclinical in vitro and in vivo studies consistently show that diet modifiers reducing the calorie have impact on tumor microenvironment and cancer metabolism, resulting in reduced growth and progression of cancer. Preliminary clinical studies show that patients subjected to a reduced nutrient/energy intake experience improved outcomes from chemo- and radiotherapy while better tolerating the side effects. Here, we review the state of the art on the therapeutic potential of calorie restriction and of caloric restriction mimetics in preventing or retarding tumor development by modulating a subset of cellular processes. The most recent clinical progresses with caloric restriction mimetics in the clinical practice are also discussed.

Sesquiterpene lactones from Carpesium abrotanoides L. and their activity in inducing protective autophagy

Fourteen sesquiterpene lactones were isolated from the whole plant of Carpesium abrotanoides L. Their structures were determined on the basis of comprehensive spectroscopic data analysis. All compounds were screened for their cytotoxic activity, and compound 6 showed the strongest activity (IC₅₀ 2.73 - 7.21 µM) against five human cancer cell lines, including A549, HepG2, HCT116, MDA-MB-231, and CNE2. Compound 6 was further investigated. Compound 6 effectively induced G2/M cell cycle arrest and ROS accumulation in a dose-dependent manner, which further led to apoptosis in cancer cells. Interestingly, compounds 1 and 6 could also activate protective autophagy, which was reported for the first time in sesquiterpene isolated from Carpesium abrotanoides. In addition, compounds 1 and 6 could induce lysosomal biogenesis by 173.2% and 163.7%, respectively. In sum, sesquiterpene lactones from Carpesium abrotanoides could induce apoptosis and protective autophagy in cancer cells, which provide a serial of compounds with potential clinical applications.

Friend or Foe: Paradoxical Roles of Autophagy in Gliomagenesis

Glioblastoma multiforme (GBM) is the most common and aggressive type of primary brain tumor in adults, with a poor median survival of approximately 15 months after diagnosis. Despite several decades of intensive research on its cancer biology, treatment for GBM remains a challenge. Autophagy, a fundamental homeostatic mechanism, is responsible for degrading and recycling damaged or defective cellular components. It plays a paradoxical role in GBM by either promoting or suppressing tumor growth depending on the cellular context. A thorough understanding of autophagy's pleiotropic roles is needed to develop potential therapeutic strategies for GBM. In this paper, we discussed molecular mechanisms and biphasic functions of autophagy in gliomagenesis. We also provided a summary of treatments for GBM, emphasizing the importance of autophagy as a promising molecular target for treating GBM.