Triptolide induces apoptosis and cytoprotective autophagy by ROS accumulation via directly targeting peroxiredoxin 2 in gastric cancer cells

The rheumatoid arthritis drug Auranofin targets peroxiredoxin 1 and peroxiredoxin 2 to trigger ROS-endoplasmic reticulum stress axis-mediated cell death and cytoprotective autophagy

Auranofin (AF) is a gold-based compound and it has been used in the treatment of rheumatoid arthritis for over four decades. Recently, it has been demonstrated to show significant antitumor activity across various cancer types and is being repurposed as an anticancer drug. However, the precise mechanisms underlying its antitumor effects, particularly its binding targets, remain poorly understood. Here, we demonstrate that Auranofin (AF) exerts cytotoxic effects in 786-O renal cancer cells via inducing apoptosis. Mechanistic studies reveal that AF induces reactive oxygen species (ROS) accumulation, which is a key factor in mediating AF-induced stress and subsequently apoptosis. Notably, both ROS and ER stress induce autophagy, and inhibition of autophagy further enhances AF-induced cytotoxicity. Interestingly, activity-based protein profiling (ABPP) analysis identifies two key antioxidant enzymes, peroxiredoxin 1 (PRDX1) and peroxiredoxin 2 (PRDX2), as direct binding targets of AF. Importantly, overexpression of PRDX1 or PRDX2 inhibits AF-induced ROS accumulation and subsequent apoptosis. Overall, our findings demonstrate that AF induces apoptosis by covalently binding to PRDX1/2 to inhibit its activity, leading to ROS accumulation, which triggers ER stress and apoptosis. At the same time, ER stress triggers a cytoprotective autophagic response. These findings provide novel insights into the mechanism of AF-induced cytotoxicity and suggest PRDX1/2 as critical targets for the development of anti-renal cancer therapies.

Dissection of the potential mechanism of polystyrene microplastic exposure on cardiomyocytes

Microplastics (MPs) are ubiquitous in the global biosphere, have widespread contact with humans, and increase exposure risks. Increasing evidence indicates that MPs exposure increases the risks of cardiovascular disease, however, a comprehensive exploration of the fundamental cellular mechanisms has yet to be undertaken. In this study, we used AC16 cells as a model and exposed them to 10 to 50 μg/mL of polystyrene MPs (PS-MPs), chosen based on the average daily intake and absorption of MPs by humans, to investigate their roles and mechanisms in cell injury. Proteomic analysis reveals that PS-MP-induced differentially expressed genes were enriched on endoplasmic reticulum (ER) stress and autophagy-related entries. The findings from immunofluorescence and western blotting provided further verification of the activation of ER stress by PS-MPs. Although the expression of LC3-II, a canonical autophagy marker was increased, PS-MPs inhibited autophagic flux instead of inducing autophagy. Importantly, ER stress not only contributes to PS-MPs-induced cell injury but also involved in PS-MPs-induced autophagic flux inhibition. Furthermore, the inhibition of autophagy, and the partial restoration of cell injury induced by PS-MPs was achieved through the activation of autophagy. Overall, the results reveal that activation of ER stress and inhibition of autophagic flux plays a significant role in the cell injury caused by PS-MPs in human cardiomyocytes, offering a novel perspective on the mechanism behind MPs-induced cardiomyocyte toxicity.

Icaritin Represses Autophagy to Promote Colorectal Cancer Cell Apoptosis and Sensitized Low-Temperature Photothermal Therapy via Targeting HSP90-TXNDC9 Interactions

Colorectal cancer (CRC) ranks among the leading causes of cancer-related dea ths worldwide, and the rising incidence and mortality of CRC underscores the urgent need for better understanding and management strategies. Icaritin (ICA) is the metabolites of icariin, a natural flavonoid glycoside compound derived from the stems and leaves of Epimedium. It has broad spectrum antitumor activity and inhibits the proliferation, migration, and invasion of CRC cells, and causes S phase cell cycle arrest. It exerts its antitumor effects against CRC through repressing autophagy to promote CRC cell apoptosis via interfering the HSP90-TXNDC9 interactions. The safety and efficacy of ICA are also affirmed in a mouse xenograft model. Additionally, to test whether ICA exerts synergistic effects with low-temperature photothermal therapy (LTPTT), a novel nanodrug delivery system, employing SiO2 nanocarriers, is designed aiming to load ICA with photothermal materials polydopamine (PDA), and folic acid (FA). This SiO2/Ica-PDA-FA multifunctional nanocomposite actively targets tumor tissues through the high affinity of FA for cancer cells. Once internalized, the acidic intracellular environment triggers the controlled release of ICA, inhibiting HSP90-TXNDC9 interactions. By LTPTT and ICA drug therapy under near-infrared illumination, a dual synergistic antitumor effect is achieved, holding promise for enhancing therapeutic outcomes in CRC treatment.

AuI-incorporated metal-organic frameworks nanozymes for thioreduction and glutathione depletion-mediated efficient photoimmunotherapy

Tumor therapy has historically been a global research focus, with phototherapy garnered significant attention as a innovative treatment modality. However, the antioxidant defense system in the tumor microenvironment, characterized by excessive glutathione (GSH) and thiol-containing proteins, often limits the effectiveness of photodynamic therapy. In this study, we report the development of a new multifunctional integrated nanozyme with thioredoxin reductase-oxidase (TrxRox) and GSH-oxidase (GSHox)-like activities. This nanozyme, termed AuI-incorporated MOFs, was synthesized by embedding monovalent Au nanozymes into a light-sensitive metal-organic framework (MOFs) structure using an in-situ oxidation-reduction method. The intergrated AuI nanozyme exhibited inhibitory effects on TrxR and presented significant anti-tumor properties. Moreover, the integrated nanozyme also demonstrates peroxidase-like activity, catalyzing the decomposition of hydrogen peroxide (H2O2) into hydroxyl radicals (•OH). Additionally, this nanomedicine effectively depletes existing GSH and TrxR, thereby enhancing the efficacy of photodynamic and photothermal therapy. Notably, under light conditions, this nanozyme induces oxidative stress within cells, leading to apoptosis and necrosis of tumor cells. Of note, it triggers immunogenic cell death and activating antigen-presenting cells to convert cold tumors into hot tumors. Therefore, AuI-incorporated MOFs nanozyme demonstrates promising potential in photoimmunotherapy, offering new insights and strategies for tumor therapy.

Role of the sulfur-containing amino acid-ROS axis in cancer chemotherapeutic drug resistance

Chemotherapeutic drug resistance remains a major barrier to effective cancer treatment. Drug resistance could be driven in part by adaptive redox remodeling of cancer cells. Paradoxically, drug-resistant malignancies exhibit elevated reactive oxygen species (ROS), as well as amplified antioxidant defenses, which enable cancer cell survival under therapeutic stress. Central to this adaptation is glutathione (GSH), the predominant cellular antioxidant, whose synthesis relies on sulfur-containing amino acids (SAAs) - methionine and cysteine. This review delineates the metabolic interplay between methionine and cysteine in the transsulfuration pathway, highlighting their roles as precursors in GSH biosynthesis. We systematically summarize the key enzymes that drive GSH production and their contributions to resistance against platinum-based drugs and other chemotherapeutics. In addition to GSH synthesis, we summarize the roles of GSH antioxidant systems, including glutathione peroxidases (GPXs), peroxiredoxins (PRDXs), and thioredoxins (TRXs), which are critical in chemotherapeutic drug resistance through ROS scavenging. Recent advances reveal that targeting these enzymes, by pharmacologically inhibiting transsulfuration enzymes or disrupting GSH-dependent antioxidant cascades, can sensitize resistant cancer cells to ROS-mediated therapies. These findings not only clarify the mechanistic links between SAA metabolism and redox adaptation but also provide practical approaches to overcome chemotherapeutic drug resistance. By analyzing metabolic and redox vulnerabilities, this review highlights the therapeutic potential to restore chemosensitivity, offering new options in precision oncology medicine.

Oxidative Stress and Redox Signaling in Gastric Cancer: From Mechanisms to Therapeutic Implications

Oxidative stress, which is characterized by an imbalance between reactive oxygen species (ROS) production and antioxidant defenses, has critical roles in the initiation, progression, and treatment of gastric cancer. On the one hand, an excessive ROS accumulation induces oxidative damage and cancer cell death. On the other hand, moderate levels of ROS cause genetic mutations and dysregulation of signaling pathways to promote proliferation, inflammation, angiogenesis, and metastasis in gastric cancer. Notably, emerging evidence has revealed that ROS also mediate oxidative post-translational modifications (oxPTMs) of redox-sensitive proteins, which can directly affect protein functions and regulate redox signaling in cancer cells. Therefore, elucidating the regulatory mechanisms of oxidative stress and redox signaling in gastric cancer holds great promise to identify novel therapeutic targets or redox-targeting strategies. This review will summarize the mechanisms of oxidative stress in regulating the hallmarks of gastric cancer and highlight the roles of ROS-mediated oxPTMs in gastric cancer. In addition, we will discuss emerging strategies targeting oxidative stress for the treatment of gastric cancer, with an emphasis on the use of bioactive natural products and nanomaterials.

Triptolide Promotes Ferroptosis in Cervical Cancer Cell via NRF2/xCT/GPX4

Cervical cancer (CC) is a serious risk to women's health; it is necessary to explore less toxic and more effective therapies to cure CC. Triptolide (Tri) is the principal active constituent found in "Tripterygium Wilford," has been shown to have antitumor effects. This study set up to demonstrate whether Tri is capable of inducing ferroptosis in CC cells and its potential mechanism. In vitro, Tri was used to treat CC cells, and lipid peroxidation levels in CC cells were detected by flow cytometry, immunofluorescence, and other experiments; the molecular mechanism of Tri treatment of CC was explored by western blot; moreover, the regulatory effects of Tri on the NRF2/GPX4/xCT axis were verified by overexpressing NRF2 in reverse. In vivo, CC cells tumor-bearing mice were constructed to observe the effect of Tri treatment on tumor growth. In vitro, we have demonstrated that Tri prevents the growth and migration of CC cells. Further investigation revealed that Tri substantially enhances ferroptosis in CC cells by increasing lipid peroxidation accumulation. Mechanically, Tri significantly reduced the expression of NRF2, leading to a corresponding repression of the NRF2 downstream targets GPX4 and xCT. Moreover, overexpressing of NRF2 effectively reversed the impact of Tri on ferroptosis in CC cells. Additionally, animal experiments indicted that Tri markedly inhibited tumor size in nude mice by inhibiting the NRF2/GPX4/xCT axis. Tri exerts antitumor effects by triggering ferroptosis in CC cells through the NRF2/GPX4/xCT axis.

NFAT5 exacerbates β-cell ferroptosis by suppressing the transcription of PRDX2 in obese type 2 diabetes mellitus

Pancreatic β-cell damage is a critical pathological mechanism in the progression of obese type 2 diabetes mellitus (T2DM). However, the exact underlying mechanism remains unclear. We established an obese T2DM mouse model via high-fat diet feeding. The protein expression profiles of pancreatic tissues from normal and obese T2DM mice were analyzed, revealing that nuclear factor of activated T cells 5 (NFAT5) and ferroptosis are potential mediators and mechanisms of β-cell damage in obese T2DM mice. In vitro, high glucose and palmitate treatment resulted in increased NFAT5 expression and nuclear translocation in MIN6 cells. Inhibition of NFAT5 expression by shRNA significantly reduced ferroptosis and improved the reduction in insulin secretion in palmitic acid and high glucose (PG)-treated MIN6 cells. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays confirmed the ability of NFAT5 to bind to the peroxiredoxin 2 (PRDX2) promoter, leading to the downregulation of PRDX2 transcription. Subsequent rescue experiments confirmed that NFAT5 is involved in PG-induced ferroptosis in MIN6 cells by inhibiting the expression of PRDX2. Finally, we demonstrated that the use of the AAV8-RIP2-miR30-shNFAT5 vector to specifically inhibit the expression of NFAT5 in β-cells significantly diminishes ferroptosis in obese T2DM mice, thereby increasing insulin secretion and improving abnormal glucose tolerance. These findings collectively highlight the therapeutic potential of targeting NFAT5 in β cells to counteract obesity-induced T2DM.

Research Progress on Natural Products That Regulate miRNAs in the Treatment of Osteosarcoma

miRNAs are small non-coding RNA molecules that play critical roles in the regulation of gene expression and have been closely associated with various diseases, including cancer. These molecules significantly influence the cell cycle of tumor cells and control programmed cell death (apoptosis). Currently, research on miRNAs has become a major focus in developing cancer therapies. Osteosarcoma, a malignant neoplasm predominantly occurring during adolescence and later in life, is characterized by a high propensity for metastasis. This review explores the role of miRNAs in the initiation and progression of cancer, highlighting their potential as predictive biomarkers for disease. It discusses the mechanisms by which natural products modulate miRNA activity to influence apoptosis, ferroptosis, and autophagy in osteosarcoma cells, aiming to identify new strategies for osteosarcoma treatment. Recent studies on how natural products regulate miRNAs to reduce tumor cell resistance to chemotherapy are also reviewed. Furthermore, the review elaborates on how natural products regulate m6A modifications to influence miRNA expression, thereby exerting antitumor effects. In this process, interactions between m6A modifications and miRNAs have been identified, with both jointly influencing tumorigenesis and cancer progression, offering a new perspective in osteosarcoma treatment. These approaches could help uncover novel regulatory mechanisms in osteosarcoma pathways and provide a theoretical foundation for developing new drugs and identifying novel therapeutic targets.

Sanguinarine suppresses oral squamous cell carcinoma progression by targeting the PKM2/TFEB aix to inhibit autophagic flux

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies. However, there is no effective treatment for OSCC.

PURPOSE

This study aimed to identify a natural compound with significant efficacy against OSCC and elucidate its primary mechanism of action.

METHODS

An FDA-approved drug library and an MCE autophagy-related molecular compound library were screened through high-throughput screening to identify an effective natural compound against OSCC. The IC50 value of sanguinarine (Sang) in OSCC cells was determined using a CCK8 assay. Immunoblotting and immunofluorescence staining were used to assess the effect of Sang on autophagic flux in OSCC cells. Changes in the acidic lysosomal environment were evaluated using RFP-GFP-LC3B and LysoSensor Green DND-189. Furthermore, limited proteolysis-coupled mass spectrometry (LiP-MS) and virtual screening techniques were utilized to identify direct binding targets of Sang, which were subsequently validated by surface plasmon resonance (SPR) and microscale thermophoresis (MST). Molecular docking combined with molecular dynamics analysis identified the binding site between the target protein and Sang. In vitro and in vivo investigations with mutant plasmids confirmed this finding.

RESULTS

Screening led to the identification of the naturally occurring autophagy modulator Sang as a potent inhibitor of OSCC progression. Moreover, Sang impaired lysosomal function through reducing lysosomal-associated membrane proteins, inhibiting lysosomal proteolysis, and altering the lysosomal pH. These effects contributed to defects in autophagic clearance and subsequently suppressed OSCC progression. Notably, Sang bound the phenylalanine 26 (F26) residue in pyruvate kinase M2 (PKM2) and inhibited PKM2 enzymatic activity, subsequently suppressing transcription factor EB (TFEB) expression to inhibit lysosomal function and blocking autophagic flux in OSCC cells.

CONCLUSION

Our results demonstrate for the first time that Sang can suppress the PKM2/TFEB axis, and influence lysosomal function, thereby blocking autophagy and inhibiting the progression of OSCC, making it a promising therapeutic option for the treatment of OSCC.

Triptolide Causes Spermatogenic Disorders by Inducing Apoptosis in the Mitochondrial Pathway of Mouse Testicular Spermatocytes

Triptolide (TP) is a diterpenoid compound extracted from the traditional Chinese medicinal herb Tripterygium wilfordii. It has antitumor and anti-inflammatory effects and stimulates immunity. However, its serious side effects, especially reproductive toxicity, limit its clinical application. This study employed a testicular injury model established by intraperitoneally injecting TP (0.2 mg/kg) in C57BL/6J male mice (age = 7-8 weeks) for 14 days. The control and TP mice's testicular tissues were subjected to transcriptome sequencing to assess potential testicular damage mechanisms. Based on the transcriptome sequencing results and relevant literature reports, further experiments were performed. In addition, to alleviate triptolide-induced testicular damage, we treated the mice with N-acetyl-L-cysteine (NAC). The acquired data revealed that compared with the control mice, the TP-treated mice's testes indicated severe damage. Transcriptome sequencing identified differentially expressed genes that showed enrichment in cell differentiation, apoptotic process, cell cycle, glutathione (GSH) metabolism, and the p53 signaling pathway. Furthermore, TUNEL assays and Western blot analysis showed that in the TP mice's testicular tissues, the spermatocytes had mitochondrial pathway apoptosis as well as abnormal mitochondrial morphology and structure. Triptolide induces oxidative stress in testicular tissue by enhancing pro-oxidative systems and inhibiting antioxidant systems. NAC reduced testicular damage and apoptosis by alleviating TP-induced oxidative stress. This study also employed a GC2 cell line for in-vitro analyses, and the results were consistent with the in vivo experiments. This study provides evidence for alleviating TP's adverse effects on the male reproductive system for better clinical application.

Modulating Endoplasmic Reticulum Stress in Gastrointestinal Cancers: Insights from Traditional Chinese Medicine

Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) play critical roles in tumorigenesis, cancer progression, and drug resistance. Persistent activation of the ER stress system enhances the survival capacities of malignant tumor cells, including increased proliferation, invasion, and resistance to treatment. Dysregulation of ER function and the resultant stress is a common cellular response to cancer therapies and may lead to cancer cell death. Currently, growing evidence suggests that Traditional Chinese medicine (TCM), either as a monotherapy or in combination with other treatments, offers significant advantages in preventing cancer, inhibiting tumor growth, reducing surgical complications, improving drug sensitivity, and mitigating drug-induced damage. Some of these natural products have even entered clinical trials as primary or complementary anticancer agents. In this review, we summarize the anticancer effects of TCM monomers/natural products on the gastrointestinal (GI) tumors and explore their mechanisms through ER stress modulation. We believe that ongoing laboratory research and the clinical development of TCM-based cancer therapies hold considerable potential for advancing future cancer treatments.

Immune escape between endoplasmic reticulum stress-related cancer cells and exhausted CD8+T cells leads to neoadjuvant chemotherapy resistance in ovarian cancer

Our study aims to explore the effects of neoadjuvant chemotherapy (NACT) on tumour cells and immune cells in the immune microenvironment of patients with high-grade serous ovarian cancer (HGSOC). Single-cell RNA sequencing data of paired ovarian cancer tissues were analysed before and after NACT in 11 patients with HGSOC. The effect of NACT on two major cell components of the tumour microenvironment, epithelial cells and CD8+T cells, was investigated. The mechanisms of epithelial cell evasion by NACT and immune killing were explored from the perspectives of gene expression, functional characteristics, transcriptional regulation, and cell communication. Key targets for reversing NACT resistance were identified and possible therapeutic strategies proposed. While NACT improved the de novo differentiation of anti-tumour CD8+T cells, enhancing their anti-tumour function, it increased the proportion of cancer cells with high HSP90B1 expression. Thus, the potential reasons for NACT resistance were identified as: 1) high levels of endoplasmic reticulum stress (ERS) characteristics, 2) high expression of the MDK-NCL ligand-receptor pair between them and exhausted CD8+T cells before NACT, and 3) high expression of the NECTIN2-TIGIT immune ligand-receptor pair between them and exhausted CD8+T cells after NACT. Thus, our study reveals the mechanisms underlying NACT resistance in patients with HGSOC from the perspective of the independent and interactive roles of cancer cells and CD8+T cells. We propose therapeutic strategies targeting the ERS marker HSP90B1 and the immune escape marker MDK before or during NACT, while targeting NECTIN2 blockade after NACT. This approach may offer new insights into combination treatments for patients with HGSOC displaying NACT resistance.

6-Phosphogluconate dehydrogenase promotes glycolysis and fatty acid synthesis by inhibiting the AMPK pathway in lung adenocarcinoma cells

Abnormal metabolism has emerged as a prominent hallmark of cancer and plays a pivotal role in carcinogenesis and progression of lung adenocarcinoma (LUAD). In this study, single-cell sequencing revealed that the metabolic enzyme 6-phosphogluconate dehydrogenase (PGD), which is a critical regulator of the pentose phosphate pathway (PPP), is significantly upregulated in the malignant epithelial cell subpopulation during malignant progression. However, the precise functional significance of PGD in LUAD and its underlying mechanisms remain elusive. Through the integration of TCGA database analysis and LUAD tissue microarray data, it was found that PGD expression was significantly upregulated in LUAD and closely correlated with a poor prognosis in LUAD patients. Moreover, in vitro and in vivo analyses demonstrated that PGD knockout and inhibition of its activity mitigated the proliferation, migration, and invasion of LUAD cells. Mechanistically, immunoprecipitation-mass spectrometry (IP-MS) revealed for the first time that IQGAP1 is a robust novel interacting protein of PGD. PGD decreased p-AMPK levels by competitively interacting with the IQ domain of the known AMPKα binding partner IQGAP1, which promoted glycolysis and fatty acid synthesis in LUAD cells. Furthermore, we demonstrated that the combination of Physcion (a PGD-specific inhibitor) and metformin (an AMPK agonist) could inhibit tumor growth more effectively both in vivo and in vitro. Collectively, these findings suggest that PGD is a potential prognostic biomarker and therapeutic target for LUAD.

Plant‐Derived Phytochemicals and Their Nanoformulations for Inducing Programed Cell Death in Cancer

Phytochemicals are a diverse class of compounds found in various plant‐based foods and beverages that have displayed the capacity to exert powerful anticancer effects through the induction of programed cell death (PCD) in malignancies. PCD is a sophisticated process that maintains in upholding tissue homeostasis and eliminating injured or neoplastic cells. Phytochemicals have shown the potential to induce PCD in malignant cells through various mechanisms, including modulation of cell signaling pathways, regulation of reactive oxygen species (ROS), and interaction with critical targets in cells such as DNA. Moreover, recent studies have suggested that nanomaterials loaded with phytochemicals may enhance cell death in tumors, which can also stimulate antitumor immunity. In this review, a comprehensive overview of the current understanding of the anticancer effects of phytochemicals and their potential as a promising approach to cancer therapy, is provided. The impacts of phytochemicals such as resveratrol, curcumin, apigenin, quercetin, and some approved plant‐derived drugs, such as taxanes on the regulation of some types of PCD, including apoptosis, pyroptosis, anoikis, autophagic cell death, ferroptosis, and necroptosis, are discussed. The underlying mechanisms and the potential of nanomaterials loaded with phytochemicals to enhance PCD in tumors are also explained.

Autophagy in benign prostatic hyperplasia: insights and therapeutic potential

Autophagy is a cellular homeostatic mechanism characterized by cyclic degradation. It plays an essential role in maintaining cellular quality and survival by eliminating dysfunctional cellular components. This process is pivotal in various pathophysiological processes. Benign prostatic hyperplasia (BPH) is a common urological disorder in middle-aged and elderly men. It frequently presents as lower urinary tract symptoms due to an increase in epithelial and stromal cells surrounding the prostatic urethra. The precise pathogenesis of BPH is complex. In recent years, research on autophagy in BPH has gained significant momentum, with accumulating evidence indicating its crucial role in the onset and progression of the disease. This review aims to outline the various roles of autophagy in BPH and elucidate potential therapeutic strategies targeting autophagy for managing BPH.

Natural products for enhancing the sensitivity or decreasing the adverse effects of anticancer drugs through regulating the redox balance

Redox imbalance is reported to play a pivotal role in tumorigenesis, cancer development, and drug resistance. Severe oxidative damage is a general consequence of cancer cell responses to treatment and may cause cancer cell death or severe adverse effects. To maintain their longevity, cancer cells can rescue redox balance and enter a state of resistance to anticancer drugs. Therefore, targeting redox signalling pathways has emerged as an attractive and prospective strategy for enhancing the efficacy of anticancer drugs and decreasing their adverse effects. Over the past few decades, natural products (NPs) have become an invaluable source for developing new anticancer drugs due to their high efficacy and low toxicity. Increasing evidence has demonstrated that many NPs exhibit remarkable antitumour effects, whether used alone or as adjuvants, and are emerging as effective approaches to enhance sensitivity and decrease the adverse effects of conventional cancer therapies by regulating redox balance. Among them are several novel anticancer drugs based on NPs that have entered clinical trials. In this review, we summarize the synergistic anticancer effects and related redox mechanisms of the combination of NPs with conventional anticancer drugs. We believe that NPs targeting redox regulation will represent promising novel candidates and provide prospects for cancer treatment in the future.

Inhibition of autophagy induced by tetrandrine promotes the accumulation of reactive oxygen species and sensitizes efficacy of tetrandrine in pancreatic cancer

Pancreatic cancer, characterized by its poor prognosis, exhibits a marked resistance to conventional chemotherapy and immunotherapy, underscoring the urgent need for more effective treatment modalities. In light of this, the present study is designed to assess the potential antineoplastic efficacy of a combined regimen involving tetrandrine, a plant-derived alkaloid, and autophagy inhibitors in the context of pancreatic cancer. Electron microscopy and immunoblots showed that tetrandrine promoted the formation of autophagosomes and the upregulation of LC3II and the downregulation of p62 expression, indicating that tetrandrine induced autophagy in pancreatic cancer cells. Western blot revealed that tetrandrine inhibited the phosphorylation of AKT and mTOR, as well as the expression of Bcl-2, while upregulating Beclin-1 expression. Moreover, tetrandrine promoted the transcription and protein expression of ATG7. Following the combination of autophagy inhibitors and tetrandrine, the apoptotic rate and cell death significantly increased in pancreatic cancer cells. Consistent results were obtained when ATG7 was silenced. Additionally, tetrandrine induced the generation of ROS, which was involved in the activation of autophagy and apoptosis. Further investigation revealed that upon autophagy inhibition, ROS accumulated in pancreatic cancer cells, resulting in decreased mitochondrial membrane potential and further induction of apoptosis. The results of treating subcutaneous xenograft tumors with a combination of tetrandrine and chloroquine validated that autophagy inhibition enhances the toxicity of tetrandrine against pancreatic cancer in vivo. Altogether, our study demonstrates that tetrandrine induces cytoprotective autophagy in pancreatic cancer cells. Inhibiting tetrandrine-induced autophagy promotes the accumulation of ROS and enhances its toxicity against pancreatic cancer.

Perfluoroalkyl sulfonate induces cardiomyocyte apoptosis via endoplasmic reticulum stress activation and autophagy flux inhibition

Perfluoroalkyl sulfonate (PFOS) is a commonly used chemical compound that often found in materials such as waterproofing agents, food packaging, and fire retardants. Known for its stability and persistence in the environment, PFOS can enter the human body through various pathways, including water and the food chain, raising concerns about its potential harm to human health. Previous studies have suggested a cardiac toxicity of PFOS, but the specific cellular mechanisms remained unclear. Here, by using AC16 cardiomyocyte as a model to investigate the molecular mechanisms potential the cardiac toxicity of PFOS. Our findings revealed that PFOS exposure reduced cell viability and induces apoptosis in human cardiomyocyte. Proteomic analysis and molecular biological techniques showed that the Endoplasmic Reticulum (ER) stress-related pathways were activated, while the cellular autophagy flux was inhibited in PFOS-exposed cells. Subsequently, we employed strategies such as autophagy activation and ER stress inhibition to alleviate the PFOS-induced apoptosis in AC16 cells. These results collectively suggest that PFOS-induced ER stress activation and autophagy flux inhibition contribute to cardiomyocyte apoptosis, providing new insights into the mechanisms of PFOS-induced cardiomyocyte toxicity.

Dysregulation of autophagy in gastric carcinoma: Pathways to tumor progression and resistance to therapy

The considerable death rates and lack of symptoms in early stages of gastric cancer (GC) make it a major health problem worldwide. One of the most prominent risk factors is infection with Helicobacter pylori. Many biological processes, including those linked with cell death, are disrupted in GC. The cellular "self-digestion" mechanism necessary for regular balance maintenance, autophagy, is at the center of this disturbance. Misregulation of autophagy, however, plays a role in the development of GC. In this review, we will examine how autophagy interacts with other cell death processes, such as apoptosis and ferroptosis, and how it affects the progression of GC. In addition to wonderful its role in the epithelial-mesenchymal transition, it is engaged in GC metastasis. The role of autophagy in GC in promoting drug resistance stands out. There is growing interest in modulating autophagy for GC treatment, with research focusing on natural compounds, small-molecule inhibitors, and nanoparticles. These approaches could lead to breakthroughs in GC therapy, offering new hope in the fight against this challenging disease.