Autophagy and chemotherapy resistance: a promising therapeutic target for cancer treatment

Covalent inhibitors possessing autophagy-modulating capabilities: charting novel avenues in drug design and discovery

Autophagy is a crucial cellular process in degrading damaged organelles and maintaining cellular homeostasis. By forming irreversible bonds with specific proteins, covalent inhibitors present a distinct advantage in regulating autophagy and its related pathways. These inhibitors can provide sustained modulation of autophagy at lower doses, improving therapeutic efficacy while minimizing adverse effects. We discuss their mechanisms, including how they affect autophagy-related enzymes and pathways, and their potential applications in the treatment of cancers and other autophagy-related disorders. Studying autophagy-related pathway targets will provide new insights for the development of covalent inhibitors and enhance therapeutic strategies for complex conditions.

Targeting mitophagy using isoliensinine as a therapeutic strategy for renal cell carcinoma treatment

Renal cell carcinoma (RCC) is a formidable and lethal form of kidney cancer, necessitating the exploration of novel therapeutic options. Isoliensinine, an alkaloid derived from lotus seed embryos, has shown promising anti-cancer properties. However, its mechanistic actions and impact on mitochondrial dynamics remain poorly understood. This research has aimed to investigate the effects of isoliensinine on RCC, as well as its potential involvement in mitophagy and mitochondrial function. In vitro experiments utilizing RCC cell lines (786-O and ACHN) have demonstrated that isoliensinine treatment significantly reduced cell viability. Moreover, isoliensinine induced an increase in cellular and mitochondrial reactive oxygen species (ROS) levels, accompanied by reduced mitochondria membrane potential, indicating an influence on mitochondrial function. Furthermore, MitoTracker staining revealed distinct mitochondrial morphologies, with isoliensinine promoting mitochondrial fission, thus supporting its role in mitochondrial dynamics. Notably, isoliensinine led to a time-dependent upregulation of mitophagy-related proteins, indicative of mitophagy activation. Of particular interest, the addition of MitoTEMPO, a potent mitochondrial ROS scavenger, effectively reversed the isoliensinine-induced upregulation of mitophagy-related protein expression and mitochondrial ROS levels. These combined results provide novel insight into the impact of isoliensinine-induced mitophagy on mitochondrial dynamics in renal carcinoma cells. Overall, the findings from this study highlight isoliensinine as a promising candidate with significant potential for further investigation and eventual clinical application in RCC therapy. Moreover, the modulation of mitochondrial dynamics, mitophagy and ROS levels through the use of isoliensinine further adds to its appeal as a potential therapeutic agent.

EM-12, a natural sesquiterpene lactone extracted from Elephantopus mollis, promotes cancer cell apoptosis by activating ER stress

The Elephantopus mollis H.B.K. contains various sesquiterpene lactones that have shown anti-proliferative and proapoptotic effects in various cancers, although the underlying mechanisms are partially understood. Inducing of excessive ER stress is a potential cancer therapeutic strategy. However, ER stress activator remain limited in current clinical applications. In this study, we identified that EM-12, an uncovered sesquiterpene lactone isolated from Elephantopus mollis H.B.K., as a BiP ATPase activity inhibitor through BiP ATPase activity assay in vitro. This molecule also exhibits significantly greater cytotoxicity in numerous ovarian cancer cell lines, including paclitaxel-resistance ovarian cancer cell line, compared to transformed ovarian epithelial cell lines. In addition, EM-12 exerts broad-spectrum cytotoxicity against various human cancer cell lines, including liver, nasopharyngeal, and breast cancer cell lines. Mechanically, EM-12 promotes ER stress and ER-stress-related apoptosis to against cancer cells through inhibiting BiP ATPase activity.

Manzamine A: A promising marine-derived cancer therapeutic for multi-targeted interactions with E2F8, SIX1, AR, GSK-3β, and V-ATPase - A systematic review

Manzamine A, a natural compound derived from various sponge genera, features a β-carboline structure and exhibits a range of biological activities, including anti-inflammatory and antimalarial effects. Its potential as an anticancer agent has been explored in several tumor models, both in vitro and in vivo, showing effects through mechanisms such as cytotoxicity, regulation of the cell cycle, inhibition of cell migration, epithelial-to-mesenchymal transition (EMT), autophagy, and apoptosis through multi-target interactions of E2F transcriptional factors, ribosomal S6 kinases, androgen receptor (AR), SIX1, GSK-3β, v-ATPase, and p53/p21/p27 cascades. This systematic review evaluates existing literature on the potential application of this marine alkaloid as a novel cancer therapy, highlighting its promising ability to inhibit cancer cell growth while causing minimal side effects.

Hotspots and frontiers of autophagy and chemotherapy in lung cancer: a bibliometric and visualization analysis from 2003 to 2023

Autophagy was considered to induce resistance in chemotherapy, which was significantly associated with proliferation of cancer; however, few bibliometric studies on the relation between autophagy and chemotherapy in lung cancer are available. The aim of the present study was to provide a comprehensive overview of the knowledge structure and research hotspots of autophagy and chemotherapy in lung cancer by bibliometric analysis. Publications related to autophagy and chemotherapy in lung cancer from 2003 to 2023 were searched on the Web of Science Core Collection (WoSCC) database. The bibliometric analysis was conducted by using VOSviewers, CiteSpace, and the R package "bibliometrix." A total of 675 articles from 70 countries, led by China and the United States, were included in the analysis. The number of publications related to autophagy and chemotherapy in lung cancer is increasing year by year. Nanjing Medical University, Zhejiang University, China Medical University, and Sichuan University are among the main research institutions contributing to this field. The journal Cancers is the most popular publication in this area, with Autophagy being the most co-cited journal. These publications involve 4481 authors, with Chiu Chien-chih and Gewirtz David having published the most papers, and Noboru Mizushima being the most frequently co-cited author. Studying the relation between autophagy and chemotherapy in the occurrence and development of lung cancer, and exploring therapeutic strategies involving autophagy and chemotherapy in lung cancer, are the primary topics in this research field. "Tumor stem cells," "microRNA," and "EGFR" emerge as the primary keywords in the emerging research hotspots. Indeed, this bibliometric study provides valuable insights into the research trends and developments concerning autophagy and chemotherapy in lung cancer. By identifying recent research frontiers and highlighting hot directions, this study serves as a valuable reference for scholars interested in understanding the relationship between autophagy and chemotherapy in lung cancer. The comprehensive summary of findings offers a foundation for further exploration and advancement in this critical area of cancer research.

Mitochondrial dysfunction route as a possible biomarker and therapy target for human cancer

Mitochondria are vital organelles found within living cells and have signalling, biosynthetic, and bioenergetic functions. Mitochondria play a crucial role in metabolic reprogramming, which is a characteristic of cancer cells and allows them to ensure a steady supply of proteins, nucleotides, and lipids to enable rapid proliferation and development. Their dysregulated activities have been associated with the growth and metastasis of different kinds of human cancer, particularly ovarian carcinoma. In this review, we briefly demonstrated the modified mitochondrial function in cancer, including mutations in mitochondrial DNA (mtDNA), reactive oxygen species (ROS) production, dynamics, apoptosis of cells, autophagy, and calcium excess to maintain cancer genesis, progression, and metastasis. Furthermore, the mitochondrial dysfunction pathway for some genomic, proteomic, and metabolomics modifications in ovarian cancer has been studied. Additionally, ovarian cancer has been linked to targeted therapies and biomarkers found through various alteration processes underlying mitochondrial dysfunction, notably targeting (ROS), metabolites, rewind metabolic pathways, and chemo-resistant ovarian carcinoma cells.

Assessing Autophagy Activation in Advanced Ovarian Cancer Using Ascitic Fluid: A Feasibility Study

INTRODUCTION

Autophagy plays a role in chemotherapy resistance by facilitating cell survival under stress conditions in many malignancies, including ovarian cancers. The use of ascitic fluid to study autophagy biomarkers is an emerging approach, with potential advantages over tissue-based studies in cancer research. This study aimed to standardize reproducible laboratory methods for detecting and quantifying autophagy biomarkers in the ascitic fluid of ovarian cancer patients.

METHODS

Ascitic fluid samples were analyzed using three techniques in 30 ovarian cancer patients: (1) enzyme-linked immunosorbent assay (ELISA) for Beclin 1, p62/sequestosome 1 (p62/sqstm1), and synaptosomal associated protein 23 (SNAP 23); (2) immunocytochemistry (ICC) for Syntaxin 17 and vesicle-associated membrane protein 8 (VAMP 8) localization; and (3) flow cytometry for epithelial cell identification and Annexin V expression assessment.

RESULTS

We standardized autophagy marker expression in ascitic fluid from ovarian cancer patients. Although the sample size was small, preliminary differences in biomarker expression were observed across disease phases. Beclin 1 levels were elevated in relapsed patients compared to newly diagnosed patients, suggesting potential autophagy activation. Further validation with larger cohorts is needed. ICC revealed heterogeneous expression of Syntaxin 17 and VAMP 8, with variations observed across patient samples. Flow cytometry identified tumor epithelial cells and Annexin V (pro-apoptotic marker) expression in these cells.

CONCLUSION

Techniques for analyzing autophagy markers in ascitic fluid were successfully standardized. The ascitic fluid analysis offers a non-invasive, accessible method for studying ovarian cancer biology, potentially enhancing understanding and management. Further research with larger cohorts and integration of traditional biomarkers could improve clinical utility in ovarian cancer.

Targeting secretory autophagy in solid cancers: mechanisms, immune regulation and clinical insights

Secretory autophagy is a classical form of unconventional secretion that integrates autophagy with the secretory process, relying on highly conserved autophagy-related molecules and playing a critical role in tumor progression and treatment resistance. Traditional autophagy is responsible for degrading intracellular substances by fusing autophagosomes with lysosomes. However, secretory autophagy uses autophagy signaling to mediate the secretion of specific substances and regulate the tumor microenvironment (TME). Cytoplasmic substances are preferentially secreted rather than directed toward lysosomal degradation, involving various selective mechanisms. Moreover, substances released by secretory autophagy convey biological signals to the TME, inducing immune dysregulation and contributing to drug resistance. Therefore, elucidating the mechanisms underlying secretory autophagy is essential for improving clinical treatments. This review systematically summarizes current knowledge of secretory autophagy, from initiation to secretion, considering inter-tumor heterogeneity, explores its role across different tumor types. Furthermore, it proposes future research directions and highlights unresolved clinical challenges.

Leveraging programmed cell death patterns to predict prognosis and therapeutic sensitivity in OSCC

OBJECTIVES

Intricate associations between programmed cell death (PCD) and cancer development and treatment outcomes have been increasingly appreciated. Here, we integrated 12 PCD patterns to construct a novel biomarker, cell death index (CDI), for oral squamous cell carcinoma (OSCC) prognostication and therapeutic prediction.

MATERIALS AND METHODS

Univariate Cox regression, Kaplan-Meier survival, and LASSO analyses were performed to construct the CDI. A nomogram combining CDI and selected clinicopathological parameters was established by multivariate Cox regression. The associations between CDI and immune landscape and therapeutic sensitivity were estimated. Single-cell RNA-seq data of OSCC was used to infer CDI genes in selected cell types and determine their expression along cell differentiation trajectory.

RESULTS

Ten selected PCD genes derived a novel prognostic signature for OSCC. The predictive prognostic performance of CDI and nomogram was robust and superior across multiple independent patient cohorts. CDI was negatively associated with tumor-infiltrating immune cell abundance and immunotherapeutic outcomes. Moreover, scRNA-seq data reanalysis revealed that GSDMB, IL-1A, PRKAA2, and SFRP1 from this signature were primarily expressed in cancer cells and involved in cell differentiation.

CONCLUSIONS

Our findings established CDI as a novel powerful predictor for prognosis and therapeutic response for OSCC and suggested its potential involvement in cancer cell differentiation.

Identification of a Privileged Scaffold for Inhibition of Sterol Transport Proteins through the Synthesis and Ring Distortion of Diverse, Pseudo-Natural Products

Sterol transport proteins mediate intracellular sterol transport, organelle contact sites, and lipid metabolism. Despite their importance, the similarities in their sterol-binding domains have made the identification of selective modulators difficult. Herein we report a combination of different compound library synthesis strategies to prepare a cholic acid-inspired compound collection for the identification of potent and selective inhibitors of sterol transport proteins. The fusion of a primary sterol scaffold with a range of different fragments found in natural products followed by various ring distortions allowed the synthesis of diverse sterol-inspired compounds. This led to the identification of a complex and three-dimensional spirooxepinoindole as a privileged scaffold for sterol transport proteins. With careful optimization of the scaffold, the selectivity could be directed toward a single transporter, as showcased by the development of a potent and selective Aster-A inhibitor. We suggest that the combination of different design strategies is generally applicable for the identification of potent and selective bioactive compounds with drug-like properties.

Autophagy in brain tumors: molecular mechanisms, challenges, and therapeutic opportunities

Autophagy is responsible for maintaining cellular balance and ensuring survival. Autophagy plays a crucial role in the development of diseases, particularly human cancers, with actions that can either promote survival or induce cell death. However, brain tumors contribute to high levels of both mortality and morbidity globally, with resistance to treatments being acquired due to genetic mutations and dysregulation of molecular mechanisms, among other factors. Hence, having knowledge of the role of molecular processes in the advancement of brain tumors is enlightening, and the current review specifically examines the role of autophagy. The discussion would focus on the molecular pathways that control autophagy in brain tumors, and its dual role as a tumor suppressor and a supporter of tumor survival. Autophagy can control the advancement of different types of brain tumors like glioblastoma, glioma, and ependymoma, demonstrating its potential for treatment. Autophagy mechanisms can influence metastasis and drug resistance in glioblastoma, and there is a complex interplay between autophagy and cellular responses to stress like hypoxia and starvation. Autophagy can inhibit the growth of brain tumors by promoting apoptosis. Hence, focusing on autophagy could offer fresh perspectives on creating successful treatments.

Optimizing autophagy modulation for enhanced TRAIL-mediated therapy: Unveiling the superiority of late-stage inhibition over early-stage inhibition to overcome therapy resistance in cancer

Autophagy is a vital mechanism that eliminates large cytoplasmic components via lysosomal degradation to maintain cellular homeostasis. The role of autophagy in cancer treatment has been studied extensively. Autophagy primarily prevents tumour initiation by maintaining genomic stability and preventing cellular inflammation. However, autophagy also supports cancer cell survival and growth by providing essential nutrients for therapeutic resistance. Thus, autophagy has emerged as a promising strategy for overcoming resistance and enhancing anti-cancer therapy. Inhibiting autophagy significantly improves the sensitivity of lung, colorectal, breast, liver and prostate cancer cells to tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). This review investigates the intricate interplay between autophagy modulation and TRAIL-based therapy, specifically focussing on comparing the efficacy of late-stage autophagy inhibition versus early-stage inhibition in overcoming cancer resistance. We expose the distinctive advantages of late-stage autophagy inhibition by exploring the mechanisms underlying autophagy's impact on TRAIL sensitivity. Current preclinical and clinical investigations are inspected, showing the potential of targeting late-stage autophagy for sensitizing resistant cancer cells to TRAIL-induced apoptosis. This review emphasizes the significance of optimizing autophagy modulation to enhance TRAIL-mediated therapy and overcome the challenge of treatment resistance in cancer. We offer insights and recommendations for guiding the development of potential therapeutic strategies aimed at overcoming the challenges posed by treatment-resistant cancers.

The contribution of the novel CLTC-VMP1 fusion gene to autophagy regulation and energy metabolism in cisplatin-resistant osteosarcoma

Osteosarcoma (OS) is a highly malignant tumor, and chemotherapy resistance is a major challenge in the treatment of this disease. This study aims to explore the role of the CLTC-VMP1 gene fusion in the mechanism of chemotherapy resistance in OS and investigate its molecular mechanisms in mediating energy metabolism reprogramming by regulating autophagy and apoptosis balance. Using single-cell transcriptome analysis, the heterogeneity of OS cells and their correlation with resistance to platinum drugs were revealed. Cisplatin-resistant cell lines were established in human OS cell lines for subsequent experiments. Based on transcriptomic analysis, the importance of VMP1 in chemotherapy resistance was confirmed. Lentiviral vectors overexpressing or interfering with VMP1 were used, and it was observed that inhibiting VMP1 could reverse cisplatin resistance, promote cell apoptosis, and inhibit autophagy, and mitochondrial respiration and glycolysis. Furthermore, the presence of CLTC-VMP1 gene fusion was validated, and its ability to regulate autophagy and apoptosis balance, promote mitochondrial respiration, and glycolysis was demonstrated. Mouse model experiments further confirmed the promoting effect of CLTC-VMP1 on tumor growth and chemotherapy resistance. In summary, the CLTC-VMP1 gene fusion mediates energy metabolism reprogramming by regulating autophagy and apoptosis balance, which promotes chemotherapy resistance in OS.NEW & NOTEWORTHY This study identifies the CLTC-VMP1 gene fusion as a key driver of chemotherapy resistance in osteosarcoma by regulating autophagy and reprogramming cellular energy metabolism. Through single-cell transcriptomics, the research reveals the heterogeneity of tumor cells and the role of VMP1 in promoting resistance to cisplatin. The findings suggest that targeting the CLTC-VMP1 fusion gene may offer new therapeutic strategies to overcome chemotherapy resistance in osteosarcoma.

L-lysine Increases the Anticancer Effect of Doxorubicin in Breast Cancer by Inducing ROS-dependent Autophagy

BACKGROUND

Doxorubicin (DOX) is a chemotherapy drug that is widely used in cancer therapy, especially in Triple-Negative Breast Cancer (TNBC) patients. Nevertheless, cytoprotective autophagy induction by DOX limits its cytotoxic effect and drug resistance induction in patients. Therefore, finding a new way is essential for increasing the effectiveness of this drug for cancer treatment.

OBJECTIVE

This study aimed to investigate the effect of L-lysine on DOX cytotoxicity, probably through autophagy modulation in TNBC cell lines.

METHODS

We used two TNBC cell lines, MDA-MB-231 and MDA-MB-468, with various levels of autophagy activity. Cell viability after treatment with L-lysine alone and in combination therapy was evaluated by MTT assay. Reactive Oxygen Species (ROS), nitric oxide (NO) concentration, and arginase activity were assessed using flow cytometric analysis, Griess reaction, and arginase activity assay kit, respectively. Real-time PCR and western blot analysis were used to evaluate the L-lysine effect on the autophagy-related genes and protein expression. Cell cycle profile and apoptotic assay were performed using flow cytometric analysis.

RESULTS

The obtained data indicated that L-lysine in both concentrations of 24 and 32 mM increased the autophagy flux and enhanced the DOX cytotoxicity, especially in MDA-MB-231, which demonstrated higher autophagy activity than MDA-MB-468, by inducing ROS and NO production. Furthermore, L-lysine induced G2/M arrest autophagy cell death, while significant apoptotic changes were not observed.

CONCLUSION

These findings suggest that L-lysine can increase DOX cytotoxicity through autophagy modulation. Thus, L-lysine, in combination with DOX, may facilitate the development of novel adjunct therapy for cancer.

The role of FOXK2-FBXO32 in breast cancer tumorigenesis: Insights into ribosome-associated pathways

OBJECTIVE

To search for a new biomarker that can predict the efficacy and prognosis of tumor immunotherapy.

METHOD

FOXK2 genes were analyzed using single-cell sequencing in pan-cancer bulk RNA-seq from the TCGA database. We used algorithms to predict their immune infiltration. Functional enrichment and ChIP-seq identified potential downstream gene, FBXO32. FBXO32's role in cancer immune response was explored through analysis.

RESULTS

Significant up-regulation of FOXK2 was observed in prostate adenocarcinoma (PRAD), uterine corpus endometrial carcinoma (UCEC), bladder urothelial carcinoma (BLCA), colorectal cancer (CRC), pancreatic ductal adenocarcinoma (PDAC), and stomach adenocarcinoma (STAD), while no such increase was found in lung cancer (lung adenocarcinoma [LUAD], lung squamous cell carcinoma [LUSC]) or thyroid carcinoma (THCA) tumor and adjacent tissues. FOXK2 expression correlated with patient prognosis, with lower expression associated with better immune response and survival and higher expression of its downstream gene FBXO32 linked to worse overall survival (OS) and immune infiltration. FOXK2 has the potential to be used as a prognostic indicator and target for treatment in individuals with cancer.

CONCLUSION

Our research provides insights into the significance of FOXK2 in cancer and indicates its potential as both a prognostic indicator and target for treatment. The ribosome-associated pathways involving FOXK2 and FBXO32 could be pivotal in the advancement of tumors, offering possible avenues for targeted and individualized immunotherapy approaches. Additional research is required to completely understand the mechanisms that are responsible for the participation of FOXK2 and its subsequent gene FBXO32 in cancer, as well as to explore the possible advantages of focusing on FOXK2 for cancer treatment.

Liposomal Formulation of Hydroxychloroquine Can Inhibit Autophagy In Vivo

Background/Objectives: Preclinical studies have shown that the anti-malarial drug hydroxychloroquine (HCQ) improves the anti-cancer effects of various therapeutic agents by impairing autophagy. These findings are difficult to translate in vivo as reaching an effective HCQ concentration at the tumor site for extended times is challenging. Previously, we found that free HCQ in combination with gefitinib (Iressa®, ZD1839) significantly reduced tumor volume in immunocompromised mice bearing gefitinib-resistant JIMT-1 breast cancer xenografts. Here, we sought to evaluate whether a liposomal formulation of HCQ could effectively modulate autophagy in vivo and augment treatment outcomes in the same tumor model. Methods: We developed two liposomal formulations of HCQ: a pH-loaded formulation and a formulation based on copper complexation. The pharmacokinetics of each formulation was evaluated in CD1 mice following intravenous administration. An efficacy study was performed in immunocompromised mice bearing established JIMT-1tumors. Autophagy markers in tumor tissue harvested after four weeks of treatment were assessed by Western blot. Results: The liposomal formulations engendered ~850-fold increases in total drug exposure over time relative to the free drug. Both liposomal and free HCQ in combination with gefitinib provided comparable therapeutic benefits (p > 0.05). An analysis of JIMT-1 tumor tissue indicated that the liposomal HCQ and gefitinib combination augmented the inhibition of autophagy in vivo compared to the free HCQ and gefitinib combination as demonstrated by increased LC3-II and p62/SQSTM1 (p62) protein levels. Conclusions: The results suggest that liposomal HCQ has a greater potential to modulate autophagy in vivo compared to free HCQ; however, this did not translate to better therapeutic effects when used in combination with gefitinib to treat a gefitinib-resistant tumor model.

Combining Chemotherapy Agents and Autophagy Modulators for Enhanced Breast Cancer Cell Death

Purpose

Autophagy, governed by genes with dual roles in cell death and survival, plays a crucial role in cancer persistence. Arsenic trioxide (ATO), carboplatin (CP), and cyclophosphamide (CY) are used to treat various cancers. ATO impedes cell proliferation and triggers apoptosis in cancer cells. CP, a platinum-based drug, damages cancer cell DNA, while CY acts as an alkylating agent, disrupting cell proliferation. This study investigates the combined effects of ATO, CP, and CY on inducing apoptosis and modulating autophagy in triple-negative breast cancer (TNBC) cell lines, BT-20 and MDA-MB-231.

Methods

The cytotoxic effects of ATO, CP, and CY, alone and in combination, were evaluated using the MTT assay on BT-20 and MDA-MB-231 cells. Apoptosis and cell cycle progression were analyzed by annexin-V FITC/PI staining and flow cytometry. Gene expression of autophagy-and apoptosis-related markers, including Beclin 1, LC3, caspase 3, and BCL2, was quantified using RT-PCR. Data were analyzed using GraphPad Prism 4.0 with one-way ANOVA followed by Dunnett's test.

Results

The combination of ATO, CP, and CY significantly reduced cell viability and enhanced apoptosis, evidenced by increased caspase-3 activity and reduced BCL2 expression. Cell cycle arrest in the G1 phase was observed, alongside elevated autophagy markers Beclin 1 and LC3.

Conclusion

The combination of ATO, CP, and CY induces synergistic effects in promoting apoptosis and autophagy in TNBC cell lines. These findings suggest that this combination therapy could be a promising approach to enhancing treatment efficacy in aggressive breast cancers, offering new insights into potential therapeutic strategies.

The Daunomycin: Biosynthesis, Actions, and the Search for New Solutions to Enhance Production

Daunorubicin (DNR) is an anthracycline antibiotic originating from soil-dwelling actinobacteria extensively used to treat malignant tumors. Over the decades, extensive attempts were made to enhance the production of anthracyclines by introducing genetic modifications and mutations in combination with media optimization, but the target production levels remain comparatively low. Developing an appropriate culture medium to maximize the yield of DNR and preventing autotoxicity for the producing organism remains a challenge. Our prospective review sheds light on a method involving perturbation that enhances the precursors to regulate the type II PKS pathway, enhancing cells' capacity to increase secondary metabolite production. The suggested method also entails the preparation of culture media for the cultivation of Streptomyces sp. and enhanced yield of DNR, as well as making it inactive with iron or its reduced forms following efflux from the producer. The iron or iron-DNR complex is encapsulated by oleic acid or lipid micelle layers in the culture media, finally resulting in the generated inactive DNR and the DNR-iron-oil complex. This idea has the potential to protect the producer organism from autotoxicity and prevent the inhibition of metabolite production. The approach of substituting sugar with oil in culture media has a dual role wherein it promotes Streptomyces growth by utilizing lipids as an energy source and encapsulating the generated DNR-iron complex in the medium. In this review, we discussed aspects like anthracycline producers, biosynthesis pathways, and gene regulation; side effects of DNR; mechanisms for autotoxicity evasion; and culture media components for the enhancement of DNR production in Streptomyces sp. We anticipate that our work will help researchers working with secondary metabolites production and decipher a methodology that would enhance DNR yield and facilitate the extraction of the resulting DNR by lowering costs in large-scale fermentation.

Lysosomal gene ATP6AP1 promotes doxorubicin resistance via up-regulating autophagic flux in breast cancer

BACKGROUND

Breast cancer remains the most prevalent malignancy in women. Chemotherapy is the primary systemic treatment modality, and the effectiveness of treatment is often hampered by chemoresistance. Autophagy has been implicated in promoting chemoresistance, as elevated autophagic flux supports tumor cell survival under therapeutic stress. Since lysosomes are essential for the completion of autophagy, their role in autophagy-related chemoresistance has been insufficiently studied. This study aims to elucidate the role of the lysosomal gene ATP6AP1 in promoting chemoresistance in breast cancer by upregulating autophagic flux.

METHODS

Doxorubicin-induced cell death was assessed by cytotoxicity, flow cytometry, lactate dehydrogenase (LDH) release assays in various breast cancer cell lines. Autophagic flux was assessed with western blot and the mRFP-GFP-LC3 fluorescence imaging. Breast cancer cells were infected with shRNA lentivirus targeting ATP6AP1, allowing investigation its tole in doxorubicin-induced cell death. ATP6AP1 expression and its association with prognosis were evaluated using public databases and immunohistochemistry.

RESULTS

Doxorubicin-induced cell death in breast cancer cells is negatively correlated with increased autophagic flux and lysosomal acidification. The lysosomal gene ATP6AP1, which plays a role in autophagic processes, is upregulated in breast cancer tissues. Knocking down ATP6AP1 reduces autophagy-mediated doxorubicin resistance by inhibiting autophagic flux and lysosomal acidification in breast cancer cells. Data analysis from public databases and our cohort indicate that elevated ATP6AP1 expression correlates with poor response to doxorubicin-based neoadjuvant chemotherapy (NAC) and worse prognosis.

CONCLUSIONS

Doxorubicin-induced cytotoxicity is associated with autophagy flux in breast cancer. The lysosomal gene ATP6AP1 facilitates autolysosome acidification and contributes to doxorubicin resistance in breast cancer.

Autophagy-based therapy for hepatocellular carcinoma: from standard treatments to combination therapy, oncolytic virotherapy, and targeted nanomedicines

Human hepatocellular carcinoma (HCC) has been identified as a significant cause of mortality worldwide. In recent years, extensive research has been conducted to understand the underlying mechanisms of autophagy in the pathogenesis of the disease, with the aim of developing novel therapeutic agents. Targeting autophagy with conventional therapies in invasive HCC has opened up new opportunities for treatment. However, the emergence of resistance and the immunosuppressive tumor environment highlight the need for combination therapy or specific targeting, as well as an efficient drug delivery system to ensure targeted tumor areas receive sufficient doses without affecting normal cells or tissues. In this review, we discuss the findings of several studies that have explored autophagy as a potential therapeutic approach in HCC. We also outline the potential and limitations of standard therapies for autophagy modulation in HCC treatment. Additionally, we discuss how different combination therapies, nano-targeted strategies, and oncolytic virotherapy could enhance autophagy-based HCC treatment in future research.

Unraveling the role of long non-coding RNAs in therapeutic resistance in acute myeloid leukemia: New prospects & challenges

Acute Myeloid Leukemia (AML) is a fatal hematological disease characterized by the unchecked proliferation of immature myeloid blasts in different tissues developed by various mutations in hematopoiesis. Despite intense chemotherapeutic regimens, patients often experience poor outcomes, leading to substandard remission rates. In recent years, long non-coding RNAs (lncRNAs) have increasingly become important prognostic and therapeutic hotspots, due to their contributions to dysregulating many functional epigenetic, transcriptional, and post-translational mechanisms leading to alterations in cell expressions, resulting in increased chemoresistance and reduced apoptosis in leukemic cells. Through this review, I highlight and discuss the latest advances in understanding the major mechanisms through which lncRNAs confer therapy resistance in AML. In addition, I also provide perspective on the current strategies to target lncRNA expressions. A better knowledge of the critical role that lncRNAs play in controlling treatment outcomes in AML will help improve existing medications and devise new ones.

The role of autophagy dysregulation in low and high-grade nonmuscle invasive bladder cancer: A survival analysis and clinicopathological association

INTRODUCTION

Bladder cancer disproportionately affects men and often presents as nonmuscle-invasive bladder cancer (NMIBC). Despite initial treatments, the recurrence and progression of NMIBC are linked to autophagy. This study investigates the expression of autophagy genes (mTOR, ULK1, Beclin1, and LC3) in low and high-grade NMIBC, providing insights into potential prognostic markers and therapeutic targets.

MATERIAL AND METHODS

A total of 115 tissue samples (n = 85 NMIBC (pTa, pT1, and CIS) and n = 30 control from BPH patients) were collected. The expression level of autophagy genes (mTOR, ULK1, Beclin1, and LC3) and their proteins were assessed in low and high-grade NMIBC, along with control tissue samples using quantitative real-time polymerase chain reaction and western blotting. Association with clinicopathological characteristics and autophagy gene expression was analyzed by multivariate and univariate survival analysis using SPSS.

RESULT

In high-grade NMIBC, ULK1, P = 0.0150, Beclin1, P = 0.0041, and LC3, P = 0.0014, were substantially downregulated, whereas mTOR, P = 0.0006, was significantly upregulated. The KM plots show significant survival outcomes with autophagy genes. The clinicopathological characters, high grade (P = 0.019), tumor stage (CIS P = 0.039, pT1 P = 0.018, P = 0.045), male (P = 0.010), lymphovascular invasion (P = 0.028) and autophagy genes (ULK1 P = 0.002, beclin1 (P = 0.010, P = 0.022) were associated as risk factors for survival outcome in NMIBC patients.

CONCLUSION

The upregulated mTOR, downregulated ULK1, and beclin1 expression is linked to a high-grade, CIS and pT1 stage, resulting in poor recurrence-free survival and progression-free survival and highlights the prognostic significance of autophagy gene in nonmuscle-invasive bladder cancer.

Dual Role of Lysosome in Cancer Development and Progression

Lysosomes are essential intracellular catabolic organelles that contain digestive enzymes involved in the degradation and recycle of damaged proteins, organelles, etc. Thus, they play an important role in various biological processes, including autophagy regulation, ion homeostasis, cell death, cell senescence. A myriad of studies has shown that the dysfunction of lysosome is implicated in human aging and various age-related diseases, including cancer. However, what is noteworthy is that the modulation of lysosome-based signaling and degradation has both the cancer-suppressive and cancer-promotive functions in diverse cancers depending on stage, biology, or tumor microenvironment. This dual role limits their application as targets in cancer therapy. In this review, we provide an overview of lysosome and autophagy-lysosomal pathway and outline their critical roles in many cellular processes, including cell death. We highlight the different functions of autophagy-lysosomal pathway in cancer development and progression, underscoring its potential as a target for effective cancer therapies.

MicroRNA-mediated autophagy and drug resistance in cancer: mechanisms and therapeutic strategies

This paper provides an exhaustive overview of the intricate interplay between microRNAs (miRNAs) and autophagy in the context of human cancers, underscoring the pivotal role these non-coding RNAs play in modulating autophagic pathways and their implications for cancer development, progression, and resistance to therapy. MiRNAs, as critical regulators of gene expression post-transcription, influence various biological processes, including autophagy, a catabolic mechanism essential for cellular homeostasis, stress response, and survival. The review meticulously delineates the mechanisms through which miRNAs impact autophagy by targeting specific genes and signaling pathways, thereby affecting cancer cell proliferation, metastasis, and response to chemotherapy. It highlights several miRNAs with dual roles, acting either as oncogenes or tumor suppressors based on the cellular context and the specific autophagic pathways they regulate. The paper further explores the therapeutic potential of targeting miRNA-autophagy axis, offering insights into novel strategies for cancer treatment through modulation of this axis. Emphasizing the complexity of the miRNA-autophagy relationship, the review calls for more in-depth studies to unravel the nuanced regulatory networks between miRNAs and autophagy in cancer, which could pave the way for the development of innovative therapeutic interventions and diagnostic tools.

A supramolecular fluorescence probe that simultaneously responds to viscosity and G-quadruplex for autophagy detection

BACKGROUND

Autophagy, as an essential physiological process in eukaryotes, has been revealed to be closely related to aging and many major diseases. Real-time in situ imaging of autophagy processes in living cells is necessary for timely detection of autophagy defects and the development of treatment methods. Currently, many studies are dedicated to the design of autophagy probes, and various types of fluorescent probes for autophagy detection have been reported. However, most of them are single fluorescence signal outputs, which may lead to non-specific signals. Nowadays a reliable and sensitive autophagy monitoring probe is still essential.

RESULTS

A supramolecular fluorescent probe was prepared via the controllable self-assembly of a thiacyanine dye named PTC for tracking autophagy in living cells. PTC was very sensitive to viscosity, and its aggregates were completely converted into monomers as viscosity increased. This process led to a significant increase of over 2000 times in the fluorescence intensity ratio between monomers and aggregates. PTC also exhibited selective affinity for G-quadruplex (G4) structure, which decomposed PTC aggregates into monomers, resulting in a fluorescence ratio increase of up to tens of folds. In living cells, PTC existed as aggregates in lysosomes, maintaining sensitivity to viscosity and G4s. In confocal imaging experiments, PTC sensitively responded to the induction and inhibition of cellular autophagy, displaying opposite changes in the monomer and aggregate fluorescent channels.

SIGNIFICANCE

This work provides a reliable fluorescent probe for autophagy detection in live cells, which has the advantages of high sensitivity, low cost, and ease of use, making it have the potential for widespread application. This study also offers a new strategy for designing autophagy probes with both high sensitivity and high specificity.

Structure-activity relationship study of small-molecule inhibitor of Atg12-Atg3 protein-protein interaction

Autophagy is a catabolic process that was described to play a critical role in advanced stages of cancer, wherein it maintains tumor cell homeostasis and growth by supplying nutrients. Autophagy is also described to support alternative cellular trafficking pathways, providing a non-canonical autophagy-dependent inflammatory cytokine secretion mechanism. Therefore, autophagy inhibitors have high potential in the treatment of cancer and acute inflammation. In our study, we identified compound 1 as an inhibitor of the ATG12-ATG3 protein-protein interaction. We focused on the systematic modification of the original hit 1, a casein kinase 2 (CK2) inhibitor, to find potent disruptors of ATG12-ATG3 protein-protein interaction. A systematic modification of the hit structure led us to a wide plethora of compounds that maintain its ATG12-ATG3 inhibitory activity, which could act as a viable starting point to design new compounds with diverse therapeutic applications.

Modulating autophagy to boost the antitumor efficacy of TROP2-directed antibody-drug conjugate in pancreatic cancer

Pancreatic cancer, characterized by a dismal prognosis and limited treatment options, persists as a formidable challenge in oncology. Trophoblast cell surface antigen 2 (TROP2)-directed antibody-drug conjugates have achieved great success in solid tumors such as breast cancer and uroepithelial carcinoma. However, their efficacy against pancreatic cancer was insufficient in clinical trials, necessitating an imperative exploration of underlying mechanisms and new therapeutic strategies. In this study, we indicated that αTROP2-MMAE, an antibody-drug conjugate targeting TROP2, induced apoptosis through the caspase-9/PARP pathway and exerted potent antitumor effects against TROP2-positive pancreatic cancer. Simultaneously, RNA sequencing suggested significant changes in autophagy after αTROP2-MMAE treatment. The formation of autophagosomes and activation of autophagic flux were markedly induced through mechanisms associated with suppressing the activation of the Akt/mTOR pathway. The addition of pharmacological inhibitors of autophagy enhanced the cytotoxicity and apoptosis caused by αTROP2-MMAE, revealing the cytoprotective role of autophagy in TROP2-positive pancreatic cancer. In the subcutaneous xenograft model using BxPC3 cells, the combined administration of αTROP2-MMAE and an autophagy inhibitor elevated the tumor inhibition rate of αTROP2-MMAE from 71.6 % to 99.0 %, resulting in the eradication of tumors in half of the mice. Collectively, our research demonstrated for the first time the cytoprotective role of autophagy in TROP2-targeted antibody-drug conjugate therapy for pancreatic cancer, providing new perspectives for mechanistic exploration and therapeutic strategies in the treatment of pancreatic cancer.

LncRNA EIF3J-DT promotes chemoresistance in oral squamous cell carcinoma

OBJECTIVES

This study aimed to screen oral squamous cell carcinoma (OSCC) diagnostic and prognostic candidates and investigate the potential functions and mechanisms of candidates in the chemoresistance of OSCC cell lines.

MATERIALS AND METHODS

Differential expression profiling of lncRNA was performed in a large cohort of OSCC patients from the Cancer Genome Atlas database to identify OSCC diagnostic and prognostic candidates. Taxol resistance in OSCC cell lines was analyzed using MTT assay. OSCC cell lines transfected with EIF3J-DT pcDNA or siRNA were used to determine its regulatory effects on apoptosis, cell cycle distribution and autophagy using flow cytometry and western blot.

RESULTS

We identified EIF3J-DT as a candidate for OSCC diagnosis and prognosis. The expression level of EIF3J-DT in OSCC cell lines correlates with taxol resistance. EIF3J-DT silencing attenuated taxol resistance, and EIF3J-DT overexpression enhanced taxol resistance in OSCC cell lines. Silencing of EIF3J-DT reduced taxol resistance by inducing apoptosis, cell cycle arrest, and ATG14-mediated autophagy inhibition in OSCC cell lines.

CONCLUSIONS

We found that EIF3J-DT induced chemoresistance by regulating apoptosis, cell cycle, and autophagy in OSCC cell lines, which EIF3J-DT might provide a novel therapeutic approach for OSCC as well as a diagnostic and prognostic factor.

Understanding the autophagic functions in cancer stem cell maintenance and therapy resistance

Complex tumour ecosystem comprising tumour cells and its associated tumour microenvironment (TME) constantly influence the tumoural behaviour and ultimately impact therapy failure, disease progression, recurrence and poor overall survival of patients. Crosstalk between tumour cells and TME amplifies the complexity by creating metabolic changes such as hypoxic environment and nutrient fluctuations. These changes in TME initiate stem cell-like programmes in cancer cells, contribute to tumoural heterogeneity and increase tumour robustness. Recent studies demonstrate the multifaceted role of autophagy in promoting fibroblast production, stemness, cancer cell survival during longer periods of dormancy, eventual growth of metastatic disease and disease resistance. Recent ongoing studies examine autophagy/mitophagy as a powerful survival strategy in response to environmental stress including nutrient deprivation, hypoxia and environmental stress in TME. It prevents irreversible senescence, promotes dormant stem-like state, induces epithelial-mesenchymal transition and increases migratory and invasive potential of tumour cells. The present review discusses various theories and mechanisms behind the autophagy-dependent induction of cancer stem cell (CSC) phenotype. Given the role of autophagic functions in CSC aggressiveness and therapeutic resistance, various mechanisms and studies based on suppressing cellular plasticity by blocking autophagy as a powerful therapeutic strategy to kill tumour cells are discussed.

Regulation of autophagy by non-coding RNAs in human glioblastoma

Glioblastoma, a lethal form of brain cancer, poses substantial challenges in treatment due to its aggressive nature and resistance to standard therapies like radiation and chemotherapy. Autophagy has a crucial role in glioblastoma progression by supporting cellular homeostasis and promoting survival under stressful conditions. Non-coding RNAs (ncRNAs) play diverse biological roles including, gene regulation, chromatin remodeling, and the maintenance of cellular homeostasis. Emerging evidence reveals the intricate regulatory mechanisms of autophagy orchestrated by non-coding RNAs (ncRNAs) in glioblastoma. The diverse roles of these ncRNAs in regulating crucial autophagy-related pathways, including AMPK/mTOR signaling, the PI3K/AKT pathway, Beclin1, and other autophagy-triggering system regulation, sheds light on ncRNAs biological mechanisms in the proliferation, invasion, and therapy response of glioblastoma cells. Furthermore, the clinical implications of targeting ncRNA-regulated autophagy as a promising therapeutic strategy for glioblastoma treatment are in the spotlight of ongoing studies. In this review, we delve into our current understanding of how ncRNAs regulate autophagy in glioblastoma, with a specific focus on microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), and their intricate interplay with therapy response.

DDX3X dynamics, glioblastoma's genetic landscape, therapeutic advances, and autophagic interplay

Glioblastoma is one of the most aggressive and deadly forms of cancer, posing significant challenges for the medical community. This review focuses on key aspects of Glioblastoma, including its genetic differences between primary and secondary types. Temozolomide is a major first-line treatment for Glioblastoma, and this article explores its development, how it works, and the issue of resistance that limits its effectiveness, prompting the need for new treatment strategies. Gene expression profiling has greatly advanced cancer research by revealing the molecular mechanisms of tumors, which is essential for creating targeted therapies for Glioblastoma. One important protein in this context is DDX3X, which plays various roles in cancer, sometimes promoting it or otherwise suppressing it. Additionally, autophagy, a process that maintains cellular balance, has complex implications in cancer treatment. Understanding autophagy helps to identify resistance mechanisms and potential treatments, with Chloroquine showing promise in treating Glioblastoma. This review covers the interplay between Glioblastoma, DDX3X, and autophagy, highlighting the challenges and potential strategies in treating this severe disease.

Inhibition of MSH6 augments the antineoplastic efficacy of cisplatin in non-small cell lung cancer as autophagy modulator

The altered response to chemotherapeutic agents predominantly stems from heightened single-point mutations within coding regions and dysregulated expression levels of genes implicated in drug resistance mechanisms. The identification of biomarkers based on mutation profiles and expression levels is pivotal for elucidating the underlying mechanisms of altered drug responses and for refining combinatorial therapeutic strategies in the field of oncology. Utilizing comprehensive bioinformatic analyses, we investigated the impact of eight mismatch repair (MMR) genes on overall survival across 23 cancer types, encompassing more than 7500 tumors, by integrating their mutation profiles. Among these genes, MSH6 emerged as the most predictive biomarker, characterized by a pronounced mutation frequency and elevated expression levels, which correlated with poorer patient survival outcomes. The wet lab experiments disclosed the impact of MSH6 in mediating altered drug responses. Cytotoxic assays conducted revealed that the depletion of MSH6 in H460 non-small lung cancer cells augmented the efficacy of cisplatin, carboplatin, and gemcitabine. Pathway analyses further delineated the involvement of MSH6 as a modulator, influencing the delicate equilibrium between the pro-survival and pro-death functions of autophagy. Our study elucidates the intricate interplay between MSH6, autophagy, and cisplatin efficacy, highlighting MSH6 as a potential therapeutic target to overcome cisplatin resistance. By revealing the modulation of autophagy pathways by MSH6 inhibition, our findings offer insights into novel approaches for enhancing the efficacy of cisplatin-based cancer therapy through targeted interventions.

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.

Progress in Research of Nanotherapeutics for Overcoming Multidrug Resistance in Cancer

Chemotherapy has been widely applied in oncotherapy. However, the development of multidrug resistance (MDR) has diminished the effectiveness of anticancer drugs against tumor cells. Such resistance often results in tumor recurrence, metastasis, and patient death. Fortunately, nanoparticle-based drug delivery systems provide a promising strategy by codelivery of multiple drugs and MDR reversal agents and the skillful, flexible, smart modification of drug targets. Such systems have demonstrated the ability to bypass the ABC transporter biological efflux mechanisms due to drug resistance. Hence, how to deliver drugs and exert potential antitumor effects have been successfully explored, applied, and developed. Furthermore, to overcome multidrug resistance, nanoparticle-based systems have been developed due to their good therapeutic effect, low side effects, and high tumor metastasis inhibition. In view of this, we systematically discuss the molecular mechanisms and therapeutic strategies of MDR from nanotherapeutics. Finally, we summarize intriguing ideas and future trends for further research in overcoming MDR.

Co-targeting NRF2 potentially enhances the in vitro anticancer effects of paclitaxel in gastric cancer cells

BACKGROUND

Gastric cancer (GC) is a highly chemoresistant malignancy with a poor prognosis. Paclitaxel's low response rate as second-line chemotherapy for advanced GC has prompted intensive research into its molecular basis and prospective targeted therapies to enhance its therapeutic efficacy. The objective of this study was to investigate the synergistic effects of NRF2 silencing in combination with paclitaxel treatment on GC cell viability, apoptosis, proliferation, autophagy, and migration.

METHODS

\After the siRNA-mediated silencing of NRF2 in AGS cells, the transfection efficacy was evaluated by qRT-PCR. The MTT assay was then applied to assess cell viability, followed by flow cytometry analysis for apoptosis, proliferation, and autophagy in AGS cells treated with NRF2 siRNA, paclitaxel, or their combination. Thereafter, the migration of cells was measured using a wound-healing assay. Ultimately, the relative gene expression levels of apoptotic (Bax, Caspase-3, and Caspase-9), anti-apoptotic (Bcl-2), metastatic (MMP-2), and cell cycle (P53) genes were measured by qRT-PCR in all experiment groups to further assess the molecular basis for the combination therapy.

RESULTS

NRF2 siRNA transfection significantly enhanced paclitaxel-induced apoptosis and sensitized AGS cells to paclitaxel via modulating the expression of apoptosis-related genes including Bcl-2, Bax, Caspase-3, and Caspase-9. Besides, NRF2 siRNA and paclitaxel synergistically induced cell cycle arrest at the G2 phase, promoted autophagy activation, and inhibited AGS cell migration via MMP-2 downregulation. Additionally, P53, a key regulator of cell growth, was significantly upregulated in the treated groups compared to the control group.

CONCLUSIONS

Our findings suggest that paclitaxel combined with siRNA-mediated silencing of NRF2 might represent a promising therapeutic strategy for GC, however further translational and clinical research are warranted.

Small non-coding RNAs and pancreatic ductal adenocarcinoma: Linking diagnosis, pathogenesis, drug resistance, and therapeutic potential

This review comprehensively investigates the intricate interplay between small non-coding RNAs (sncRNAs) and pancreatic ductal adenocarcinoma (PDAC), a devastating malignancy with limited therapeutic options. Our analysis reveals the pivotal roles of sncRNAs in various facets of PDAC biology, spanning diagnosis, pathogenesis, drug resistance, and therapeutic strategies. sncRNAs have emerged as promising biomarkers for PDAC, demonstrating distinct expression profiles in diseased tissues. sncRNA differential expression patterns, often detectable in bodily fluids, hold potential for early and minimally invasive diagnostic approaches. Furthermore, sncRNAs exhibit intricate involvement in PDAC pathogenesis, regulating critical cellular processes such as proliferation, apoptosis, and metastasis. Additionally, mechanistic insights into sncRNA-mediated pathogenic pathways illuminate novel therapeutic targets and interventions. A significant focus of this review is dedicated to unraveling sncRNA mechanisms underlying drug resistance in PDAC. Understanding these mechanisms at the molecular level is imperative for devising strategies to overcome drug resistance. Exploring the therapeutic landscape, we discuss the potential of sncRNAs as therapeutic agents themselves as their ability to modulate gene expression with high specificity renders them attractive candidates for targeted therapy. In summary, this review integrates current knowledge on sncRNAs in PDAC, offering a holistic perspective on their diagnostic, pathogenic, and therapeutic relevance. By elucidating the roles of sncRNAs in PDAC biology, this review provides valuable insights for the development of novel diagnostic tools and targeted therapeutic approaches, crucial for improving the prognosis of PDAC patients.

Selective COX-2 inhibitors as anticancer agents: a patent review (2018-2023)

INTRODUCTION

COX-2 is a crucial enzyme in the manufacture of prostaglandins. The enzyme's metabolites might have an important function as regulators of the inflammatory response and other medical conditions such as cancer. Selective COX-2 inhibitors are believed to enhance or reverse the response of cancer chemotherapeutics.

AREAS COVERED

This study addresses the chemical structures as well as the antitumor activity of new COX-2 inhibitors produced in the recent five years, aiming to provide an insight into the mechanism of COX-2 induced PGE2 powerful signal in cancer development.

EXPERT OPINION

The significance of selective COX-2 inhibitors as an efficient superfamily of compounds with anti-inflammatory, anti-Alzheimer's, anti-Parkinson's disease, and anticancer properties has piqued the passion of academics in the field of drug development. Long-term usage of selective COX-2 inhibitors, such as celecoxib has been proven in clinical trials to lower the incidence of several human malignancies. Furthermore, celecoxib has the potential to greatly increase the effectiveness of chemotherapy. Our extensive understanding of selective COX-2 inhibitor SAR may aid in the development of safer and more effective selective COX-2 inhibitors as cancer chemopreventive agents. This review focuses on the different structural classes of selective COX-2 inhibitors, with a particular emphasis on their SAR.

Is Autophagy Targeting a Valid Adjuvant Strategy in Conjunction with Tyrosine Kinase Inhibitors?

Tyrosine kinase inhibitors (TKIs) represent a relatively large class of small-molecule inhibitors that compete with ATP for the catalytic binding site of tyrosine kinase proteins. While TKIs have demonstrated effectiveness in the treatment of multiple malignancies, including chronic myelogenous leukemia, gastrointestinal tumors, non-small cell lung cancers, and HER2-overexpressing breast cancers, as is almost always the case with anti-neoplastic agents, the development of resistance often imposes a limit on drug efficacy. One common survival response utilized by tumor cells to ensure their survival in response to different stressors, including anti-neoplastic drugs, is that of autophagy. The autophagic machinery in response to TKIs in multiple tumor models has largely been shown to be cytoprotective in nature, although there are a number of cases where autophagy has demonstrated a cytotoxic function. In this review, we provide an overview of the literature examining the role that autophagy plays in response to TKIs in different preclinical tumor model systems in an effort to determine whether autophagy suppression or modulation could be an effective adjuvant strategy to increase efficiency and/or overcome resistance to TKIs.

Importance of Autophagy Regulation in Glioblastoma with Temozolomide Resistance

Glioblastoma (GBM) is the most aggressive and common malignant and CNS tumor, accounting for 47.7% of total cases. Glioblastoma has an incidence rate of 3.21 cases per 100,000 people. The regulation of autophagy, a conserved cellular process involved in the degradation and recycling of cellular components, has been found to play an important role in GBM pathogenesis and response to therapy. Autophagy plays a dual role in promoting tumor survival and apoptosis, and here we discuss the complex interplay between autophagy and GBM. We summarize the mechanisms underlying autophagy dysregulation in GBM, including PI3K/AKT/mTOR signaling, which is most active in brain tumors, and EGFR and mutant EGFRvIII. We also review potential therapeutic strategies that target autophagy for the treatment of GBM, such as autophagy inhibitors used in combination with the standard of care, TMZ. We discuss our current understanding of how autophagy is involved in TMZ resistance and its role in glioblastoma development and survival.

FoxG1/BNIP3 axis promotes mitophagy and blunts cisplatin resistance in osteosarcoma

Cisplatin (CDDP) is a commonly used chemotherapeutic for osteosarcoma (OS) patients, and drug resistance remains as a major hurdle to undermine the treatment outcome. Here, we investigated the potential involvement of FoxG1 and BNIP3 in CDDP resistance of OS cells. FoxG1 and BNIP3 expression levels were detected in the CDDP-sensitive and CDDP-resistant OS tumors and cell lines. Mitophagy was observed through transmission electron microscope analysis. The sensitivity to CDDP in OS cells upon FoxG1 overexpression was examined in cell and animal models. We found that FoxG1 and BNIP3 showed significant downregulation in the CDDP-resistant OS tumor samples and cell lines. CDDP-resistant OS tumor specimens and cells displayed impaired mitophagy. FoxG1 overexpression promoted BNIP3 expression, enhanced mitophagy in CDDP-resistant OS cells, and resensitized the resistant cells to CDDP treatment in vitro and in vivo. Our data highlighted the role of the FoxG1/BNIP3 axis in regulating mitophagy and dictating CDDP resistance in OS cells, suggesting targeting FoxG1/BNIP3-dependent mitophagy as a potential strategy to overcome CDDP resistance in OS.

Let's make it personal: CRISPR tools in manipulating cell death pathways for cancer treatment

Advancements in the CRISPR technology, a game-changer in experimental research, have revolutionized various fields of life sciences and more profoundly, cancer research. Cell death pathways are among the most deregulated in cancer cells and are considered as critical aspects in cancer development. Through decades, our knowledge of the mechanisms orchestrating programmed cellular death has increased substantially, attributed to the revolution of cutting-edge technologies. The heroic appearance of CRISPR systems have expanded the available screening platform and genome engineering toolbox to detect mutations and create precise genome edits. In that context, the precise ability of this system for identification and targeting of mutations in cell death signaling pathways that result in cancer development and therapy resistance is an auspicious choice to transform and accelerate the individualized cancer therapy. The concept of personalized cancer therapy stands on the identification of molecular characterization of the individual tumor and its microenvironment in order to provide a precise treatment with the highest possible outcome and minimum toxicity. This study explored the potential of CRISPR technology in precision cancer treatment by identifying and targeting specific cell death pathways. It showed the promise of CRISPR in finding key components and mutations involved in programmed cell death, making it a potential tool for targeted cancer therapy. However, this study also highlighted the challenges and limitations that need to be addressed in future research to fully realize the potential of CRISPR in cancer treatment.

Complex Interplay between DNA Damage and Autophagy in Disease and Therapy

Cancer, a multifactorial disease characterized by uncontrolled cellular proliferation, remains a global health challenge with significant morbidity and mortality. Genomic and molecular aberrations, coupled with environmental factors, contribute to its heterogeneity and complexity. Chemotherapeutic agents like doxorubicin (Dox) have shown efficacy against various cancers but are hindered by dose-dependent cytotoxicity, particularly on vital organs like the heart and brain. Autophagy, a cellular process involved in self-degradation and recycling, emerges as a promising therapeutic target in cancer therapy and neurodegenerative diseases. Dysregulation of autophagy contributes to cancer progression and drug resistance, while its modulation holds the potential to enhance treatment outcomes and mitigate adverse effects. Additionally, emerging evidence suggests a potential link between autophagy, DNA damage, and caretaker breast cancer genes BRCA1/2, highlighting the interplay between DNA repair mechanisms and cellular homeostasis. This review explores the intricate relationship between cancer, Dox-induced cytotoxicity, autophagy modulation, and the potential implications of autophagy in DNA damage repair pathways, particularly in the context of BRCA1/2 mutations.

Investigating the molecular mechanisms of microRNA‑409‑3p in tumor progression: Towards targeted therapeutics (Review)

MicroRNAs (miRNAs) are a group of non‑coding RNAs that exert master regulatory functions in post‑-transcriptional gene expression. Accumulating evidence shows that miRNAs can either promote or suppress tumorigenesis by regulating different target genes or pathways and may be involved in the occurrence of carcinoma. miR‑409‑3p is dysregulated in a variety of malignant cancers. It plays a fundamental role in numerous cellular biological processes, such as cell proliferation, apoptosis, migration, invasion, autophagy, angiogenesis and glycolysis. In addition, studies have shown that miR‑409‑3p is expected to become a non‑invasive biomarker. Identifying the molecular mechanisms underlying miR‑409‑3p‑mediated tumor progression will help investigate miR‑409‑3p‑based targeted therapy for human cancers. The present review comprehensively summarized the recently published literature on miR‑409‑3p, with a focus on the regulation and function of miR‑409‑3p in various types of cancer, and discussed the clinical implications of miR‑409‑3p, providing new insight for the diagnosis and treatment of cancers.

An updated review of the pharmacological effects and potential mechanisms of hederagenin and its derivatives

Hederagenin (HG) is a natural pentacyclic triterpenoid that can be isolated from various medicinal herbs. By modifying the structure of HG, multiple derivatives with superior biological activities and safety profiles have been designed and synthesized. Accumulating evidence has demonstrated that HG and its derivatives display multiple pharmacological activities against cancers, inflammatory diseases, infectious diseases, metabolic diseases, fibrotic diseases, cerebrovascular and neurodegenerative diseases, and depression. Previous studies have confirmed that HG and its derivatives combat cancer by exerting cytotoxicity, inhibiting proliferation, inducing apoptosis, modulating autophagy, and reversing chemotherapy resistance in cancer cells, and the action targets involved mainly include STAT3, Aurora B, KIF7, PI3K/AKT, NF-κB, Nrf2/ARE, Drp1, and P-gp. In addition, HG and its derivatives antagonize inflammation through inhibiting the production and release of pro-inflammatory cytokines and inflammatory mediators by regulating inflammation-related pathways and targets, such as NF-κB, MAPK, JAK2/STAT3, Keap1-Nrf2/HO-1, and LncRNA A33/Axin2/β-catenin. Moreover, anti-pathogen, anti-metabolic disorder, anti-fibrosis, neuroprotection, and anti-depression mechanisms of HG and its derivatives have been partially elucidated. The diverse pharmacological properties of HG and its derivatives hold significant implications for future research and development of new drugs derived from HG, which can lead to improved effectiveness and safety profiles.

Endoplasmic reticulum stress and quality control in relation to cisplatin resistance in tumor cells

The endoplasmic reticulum (ER) is a crucial organelle that orchestrates key cellular functions like protein folding and lipid biosynthesis. However, it is highly sensitive to disturbances that lead to ER stress. In response, the unfolded protein response (UPR) activates to restore ER homeostasis, primarily through three sensors: IRE1, ATF6, and PERK. ERAD and autophagy are crucial in mitigating ER stress, yet their dysregulation can lead to the accumulation of misfolded proteins. Cisplatin, a commonly used chemotherapy drug, induces ER stress in tumor cells, activating complex signaling pathways. Resistance to cisplatin stems from reduced drug accumulation, activation of DNA repair, and anti-apoptotic mechanisms. Notably, cisplatin-induced ER stress can dualistically affect tumor cells, promoting either survival or apoptosis, depending on the context. ERAD is crucial for degrading misfolded proteins, whereas autophagy can protect cells from apoptosis or enhance ER stress-induced apoptosis. The complex interaction between ER stress, cisplatin resistance, ERAD, and autophagy opens new avenues for cancer treatment. Understanding these processes could lead to innovative strategies that overcome chemoresistance, potentially improving outcomes of cisplatin-based cancer treatments. This comprehensive review provides a multifaceted perspective on the complex mechanisms of ER stress, cisplatin resistance, and their implications in cancer therapy.

An oncogenic role of lncRNA SNHG1 promotes ATG7 expression and autophagy involving tumor progression and sunitinib resistance of Renal Cell Carcinoma

Renal cell carcinoma (RCC) is a malignant tumor with high incidence in adult kidney. Long non-coding RNAs (lncRNAs) have recently been recognized as important regulators in the development of RCC. However, whether lncRNA SNHG1 is associated with RCC progression remains to be elucidated. Here, the role of SNHG1 in RCC autophagy and sunitinib resistance was evaluated. Expression of SNHG1 in RCC tissues and cells was assessed using RT-qPCR. Western blot was utilized to measure the levels of autophagy-related molecules and ATG7. RNA pull-down and RIP assays were performed to confirm the molecular axis between SNHG1/PTBP1/ATG7. Cell proliferation, migration, invasion and apoptosis were analyzed by CCK-8, EdU, transwell and flow cytometry, respectively. The subcellular localization of SNHG1 was determined by an intracellular fractionation assay. The fluorescence intensity of GFP-LC3 autophagosome in RCC cells was detected. IHC staining was performed to test ATG7 expression in tumor tissues from nude mice. Here, a positive correlation of upregulated SNHG1 with poor prognosis of RCC patients was observed in RCC tissues and cells. SNHG1 knockdown suppressed tumor growth and reversed sunitinib resistance and autophagy of RCC cells. Additionally, SNHG1 was found to directly bind to PTBP1, thereby positively regulating ATG7 expression. Furthermore, we verified that SNHG1 mediated the malignant behavior of RCC cells through the PTBP1/ATG7 axis. To sum up, SNHG1 regulates RCC cell autophagy and sunitinib resistance through the PTBP1/ATG7 axis, which highlights a promising therapeutic target for RCC treatment.

The impact of ribosome biogenesis in cancer: from proliferation to metastasis

The dysregulation of ribosome biogenesis is a hallmark of cancer, facilitating the adaptation to altered translational demands essential for various aspects of tumor progression. This review explores the intricate interplay between ribosome biogenesis and cancer development, highlighting dynamic regulation orchestrated by key oncogenic signaling pathways. Recent studies reveal the multifaceted roles of ribosomes, extending beyond protein factories to include regulatory functions in mRNA translation. Dysregulated ribosome biogenesis not only hampers precise control of global protein production and proliferation but also influences processes such as the maintenance of stem cell-like properties and epithelial-mesenchymal transition, contributing to cancer progression. Interference with ribosome biogenesis, notably through RNA Pol I inhibition, elicits a stress response marked by nucleolar integrity loss, and subsequent G1-cell cycle arrest or cell death. These findings suggest that cancer cells may rely on heightened RNA Pol I transcription, rendering ribosomal RNA synthesis a potential therapeutic vulnerability. The review further explores targeting ribosome biogenesis vulnerabilities as a promising strategy to disrupt global ribosome production, presenting therapeutic opportunities for cancer treatment.

Autophagy in cancer immunotherapy: Perspective on immune evasion and cell death interactions

Both the innate and adaptive immune systems work together to produce immunity. Cancer immunotherapy is a novel approach to tumor suppression that has arisen in response to the ineffectiveness of traditional treatments like radiation and chemotherapy. On the other hand, immune evasion can diminish immunotherapy's efficacy. There has been a lot of focus in recent years on autophagy and other underlying mechanisms that impact the possibility of cancer immunotherapy. The primary feature of autophagy is the synthesis of autophagosomes, which engulf cytoplasmic components and destroy them by lysosomal degradation. The planned cell death mechanism known as autophagy can have opposite effects on carcinogenesis, either increasing or decreasing it. It is autophagy's job to maintain the balance and proper functioning of immune cells like B cells, T cells, and others. In addition, autophagy controls whether macrophages adopt the immunomodulatory M1 or M2 phenotype. The ability of autophagy to control the innate and adaptive immune systems is noteworthy. Interleukins and chemokines are immunological checkpoint chemicals that autophagy regulates. Reducing antigen presentation to induce immunological tolerance is another mechanism by which autophagy promotes cancer survival. Therefore, targeting autophagy is of importance for enhancing potential of cancer immunotherapy.

Autophagy suppression in DNA damaged cells occurs through a newly identified p53-proteasome-LC3 axis

Macroautophagy is thought to have a critical role in shaping and refining cellular proteostasis in eukaryotic cells recovering from DNA damage. Here, we report a mechanism by which autophagy is suppressed in cells exposed to bacterial toxin-, chemical-, or radiation-mediated sources of genotoxicity. Autophagy suppression is directly linked to cellular responses to DNA damage, and specifically the stabilization of the tumor suppressor p53, which is both required and sufficient for regulating the ubiquitination and proteasome-dependent reduction in cellular pools of microtubule-associated protein 1 light chain 3 (LC3A/B), a key precursor of autophagosome biogenesis and maturation, in both epithelial cells and an ex vivo organoid model. Our data indicate that suppression of autophagy, through a newly identified p53-proteasome-LC3 axis, is a conserved cellular response to multiple sources of genotoxicity. Such a mechanism could potentially be important for realigning proteostasis in cells undergoing DNA damage repair.