Autophagy in cancer development, immune evasion, and drug resistance

Pharmacological, computational, and mechanistic insights into triptolide's role in targeting drug-resistant cancers

As a promising candidate for tackling drug-resistant cancers, triptolide, a diterpenoid derived from the Chinese medicinal plant Tripterygium wilfordii, has been developed. This review summarizes potential antitumor activities, including the suppression of RNA polymerase II, the suppression of heat shock proteins (HSP70 and HSP90), and the blockade of NF-kB signalling. Triptolide is the first known compound to target cancer cells specifically but spare normal cells, and it has success in treating cancers that are difficult to treat, including pancreatic, breast, and lung cancers. It acts against the tolerance mechanisms, including efflux pump upregulation, epithelial-mesenchymal transition, and cancer stem cells. Triptolide modulates important cascades, including PI3K/AKT/mTOR, enhancing the efficacy of conventional therapies. Nonetheless, its clinical application is constrained by toxicity and bioavailability challenges. Emerging drug delivery systems, such as nanoparticles and micellar formulations, are being developed to address these limitations. It has strong interactions with key anticancer targets, like PARP, as determined in preclinical and computational studies consistent with its mechanism of action. Early-phase clinical trials of Minnelide, a water-soluble derivative of triptolide, are promising, but additional work is necessary to optimize dosing, delivery, and safety. This comprehensive analysis demonstrates that triptolide may constitute a repurposed precision medicine tool to overcome tolerance in cancer therapy.

Advances in the role of baicalin and baicalein in colon cancer: mechanisms and therapeutic potential

Colorectal cancer (CRC) remains a malignancy with high incidence and mortality rates worldwide, necessitating the development of more effective therapeutic strategies due to the limitations of current treatments, including drug resistance and adverse effects. Scutellaria baicalensis, a traditional Chinese medicinal herb, contains baicalin and baicalein as its primary bioactive flavonoids, which exhibit notable pharmacological properties such as antibacterial, anti-inflammatory, antioxidant, and antitumor effects. Recent studies have demonstrated that baicalin and baicalein show promising antitumor activity in CRC treatment through mechanisms such as scavenging reactive oxygen species, immune regulation, and inhibition of tumor cell proliferation, induction of apoptosis, and modulation of the gut microenvironment. This study further investigates the molecular mechanisms underlying the therapeutic effects of baicalin and baicalein in CRC, aiming to provide new research perspectives and potential clinical applications for the integration of flavonoid-based compounds from Scutellaria baicalensis in CRC treatment.

Mechanisms and potential therapeutic strategies of withaferin A in breast cancer

Breast cancer (BC) is one of the most common malignant tumors in women worldwide, and its treatment faces numerous challenges. Despite the effectiveness of modern treatment methods such as surgery, radiotherapy, chemotherapy, and targeted therapy, issues like recurrence, metastasis, and drug resistance still significantly affect patient prognosis and survival rates. This is particularly true for triple-negative breast cancer (TNBC) and HER2-positive BC, for which treatment outcomes are relatively poor. Withaferin A (WA), a natural plant-derived compound, has shown significant anti-cancer effects in the treatment of BC. WA inhibits the progression of BC through multiple mechanisms, including suppressing cell migration and invasion, inducing tumor cell apoptosis, regulating autophagy and metabolic pathways, and modulating miRNA expression. In combination therapy, WA exhibits a good synergistic effect when used with other anti-cancer drugs such as phenethyl isothiocyanate (PEITC), cisplatin, and sulforaphane, significantly enhancing therapeutic efficacy and reducing drug resistance. This review summarizes the research progress on the mechanisms of WA in combating BC, aiming to provide a foundation for the scientific development and clinical application of WA in BC treatment.

Translating preclinical insights into clinical strategies: Targeting cancer stem cells and stemness in prostate cancer

CSCs represent a unique group within the tumor microenvironment (TME) elevating the tumorigenesis. The cause of cancer recurrence can also be investigated in the function of CSCs possessing self-renewing capabilities and differentiation into various types of cells. Prostate cancer (PCa) is a malignant disease of the urogenital system characterized by aggressive behavior and heterogeneous nature due to the dysregulation of molecular pathways and the interactions among cells within the TME. The PCa can quickly become resistant to standard chemotherapy and other kinds of therapies such as radiotherapy along with ability to mediate immune evasion. The focus of biology has been on the molecular and cellular alterations in PCa. The CSCs have been recognized as potential biomarkers for predicting the outcome of prostate PCa. Furthermore, a positive correlation exists between CSCs and the metastatic growth and stemness of PCa. The existence of hypoxia enhances the stemness of PCa, and CSCs play a role in dormancy. Genomic and epigenetic elements, including non-coding RNAs, can influence CSCs and the advancement of PCa. Additionally, therapeutic agents and nanotechnology methods aimed at targeting CSCs have been developed to inhibit CSCs in PCa treatment.

Harnessing immunotherapy for hepatocellular carcinoma: Principles and emerging promises

HCC is considered as one of the leadin causes of death worldwide, with the ability of resistance towards therapeutics. Immunotherapy, particularly ICIs, have provided siginficant insights towards harnessing the immune system. The present review introduces the concepts and possibilities of immunotherapy for HCC treatment, emphasizing its underlying mechanisms and capacity to enhance patient results, focusing on both pre-clinical and clinical insights. The functions of TME and immune evasion mechanisms typical of HCC would be evaluated along with how contemporary immunotherapeutic approaches are designed to address these challenges. Furthermore, the clinical application of immunotherapy in HCC is discussed, emphasizing recent trial findings demonstrating the effectiveness and safety of drugs. In addition, the problems caused by immune evasion and resistance would be discussed to increase potential of immunotherapy along with combination therapy.

Inflammasomes and autophagy in cancer: unlocking targeted therapies

This study clarifies the interaction between autophagy and inflammasome within the cancer framework. The inflammasome generates pro-inflammatory cytokines to direct the immune response to pathogens and cellular stressors. Autophagy maintains cellular homeostasis and can either promote or inhibit cancer. These pathways interact to affect tumorigenesis, immune responses, and therapy. Autophagy controls inflammasome activity by affecting cancer pathogenesis and tumor microenvironment inflammation, highlighting novel cancer therapeutic approaches. Recent studies indicate that modulating autophagy and inflammasome pathways can boost anti-cancer immunity, reduce drug-resistance, and improve therapeutic efficacy. Recent studies indicate modulating inflammasome and autophagy pathways can augment anti-cancer immunity, mitigate therapy resistance, and improve treatment efficacy. Cancer research relies on understanding the inflammasome-autophagy relationship to develop targeted therapies that enhance anti-tumor efficacy and reduce inflammatory symptoms. Customized therapies may improve outcomes based on autophagy gene variations and inflammasome polymorphisms. This study investigates autophagy pathways and the inflammasome in tumor immunopathogenesis, cytokine function, and cancer therapeutic strategies, highlighting their significance in cancer biology and treatment.

Bionic gene delivery system activates tumor autophagy and immunosuppressive niche to sensitize anti-PD-1 treatment against STK11-mutated lung adenocarcinoma

Clinical data have shown that Serine/Threonine Kinase 11 (STK11) mutation may be associated with an immunosuppressive tumor microenvironment (ITEM) and poor prognosis and failure of anti-PD-1 (αPD1) treatment in non-small cell lung cancer (NSCLC). To explore the potential of restoring STK11 protein in immunotherapy, a bionic gene delivery system was prepared by coating the STK11-encoded DNA-cationic polymer complex core with the tumor cell membrane, termed STK11@PPCM. STK11@PPCM could specifically bind with NSCLC cells and achieve precise delivery of STK11-encoded DNA. The released DNA effectively restored the STK11 protein expression, consequently reactivating autophagy and immunogenic cell death (ICD) in cancer cells. The liberated damage-associated molecular patterns (DAMPs) and autophagosome induced dendritic cells (DCs) maturation, which in turn enhanced CD8 + T cell infiltration, M1 macrophage polarization, and proinflammatory factor expression, thereby reversing the ITEM. Moreover, STK11@PPCM was also found to improve the sensitivity of cancer cells to αPD1 by increasing the expression of PD-L1, which was confirmed in STK11-mutated NSCLC cell xenografted mouse models, constructed by CRISPR-Cas9 knockout technology. This work demonstrated for the first time that restoration of functional STK11 can effectively reverse ITME and boost αPD1 efficacy in NSCLC, offering a new therapeutic approach for STK11-mutated lung adenocarcinoma in clinic.

Glutamine's double-edged sword: fueling tumor growth and offering therapeutic hope

Tumor metabolic reprogramming is a highly complex process that enables tumor survival in the presence of limited nutrients, involving multiple signaling pathways, non-coding RNAs (ncRNAs), and transcription factors. Lately, glutamine has been found to enhance the growth, spread, and drug resistance of cancer cells, while also fostering an immunosuppressive microenvironment that aids tumor development. However, in some tumors, such as pancreatic cancer and melanoma, additional glutamine can inhibit the proliferation of tumor cells, and this mechanism is closely related to the regulation of the immune microenvironment. Therefore, further exploration of glutamine metabolism in tumors is essential for understanding the pathogenesis of cancer and for developing new metabolically targeted therapies. We systematically review the latest research on the reprogramming of glutamine metabolism and its role of tumor growth, spread, and immune system regulation. Additionally, we review the clinical research progress on targeted glutamine therapies and their application in combination with current anti-tumor treatments. Ultimately, we address the challenges and prospects involved in resistance to anti-cancer strategies aimed at glutamine metabolism.

Navigating the future of gastric cancer treatment: a review on the impact of antibody-drug conjugates

Gastric cancer, marked by its high incidence and poor prognosis, demands the urgent development of novel and effective treatment strategies, especially for patients ineligible for surgery or those who have had limited success with chemotherapy, radiotherapy and targeted therapies. Recently, antibody-drug conjugates (ADCs) have become a key area of investigation due to their high specificity and potent antitumor effects. These therapies combine monoclonal antibodies, designed to bind to tumor-specific antigens, with cytotoxic agents that selectively target and destroy malignant cells. ADCs have generated significant interest in clinical trials as a promising approach to improve both treatment efficacy and patient outcomes in gastric cancer. However, their clinical application is not without challenges and limitations that must be addressed. This review discusses the recent progress in the use of ADCs for gastric cancer treatment.

Autophagy in tumor immune escape and immunotherapy

The immunotherapy targeting tumor immune escape mechanisms has become a critical strategy in anticancer treatment; however, the challenge of immune resistance remains significant. Autophagy, a cellular response to various stressors, involves the degradation of damaged proteins and organelles via lysosomal pathways, maintaining cellular homeostasis. This process not only supports tumor cell survival but also profoundly impacts the efficacy of cancer immunotherapies. The modulation of autophagy in tumor cells or immune cells exerts dual effects on tumor immune escape and immunotherapy. However, the mechanistic details of how autophagy influences the immune system and therapy remain inadequately understood. Given this complexity, a deeper understanding of the role of autophagy in the tumor-immune landscape could reveal novel therapeutic avenues. By manipulating autophagy appropriately, it may be possible to overcome immune resistance and enhance the effectiveness of immunotherapeutic strategies. This article summarizes the role of autophagy in tumor immunity, its relationship with immunotherapy, and the potential therapeutic benefits of targeting autophagy to strengthen antitumor immune responses and optimize the outcomes of immunotherapy.

Unraveling the triad of hypoxia, cancer cell stemness, and drug resistance

In the domain of addressing cancer resistance, challenges such as limited effectiveness and treatment resistance remain persistent. Hypoxia is a key feature of solid tumors and is strongly associated with poor prognosis in cancer patients. Another significant portion of the development of acquired drug resistance is attributed to tumor stemness. Cancer stem cells (CSCs), a small tumor cell subset with self-renewal and proliferative abilities, are crucial for tumor initiation, metastasis, and intra-tumoral heterogeneity. Studies have shown a significant association between hypoxia and CSCs in the context of tumor resistance. Recent studies reveal a strong link between hypoxia and tumor stemness, which together promote tumor survival and progression during treatment. This review elucidates the interplay between hypoxia and CSCs, as well as their correlation with resistance to therapeutic drugs. Targeting pivotal genes associated with hypoxia and stemness holds promise for the development of novel therapeutics to combat tumor resistance.

Metabolism-Related Programmed Cell Death: Unveiling Prognostic Biomarkers, Immune Checkpoints, and Therapeutic Strategies in Ovarian Cancer

BACKGROUND

Ovarian cancer (OC), the gynecologic malignancy with the poorest prognosis, is driven by metabolic reprogramming and dysregulated programmed cell death (PCD). However, their interplay and prognostic significance remain inadequately understood.

METHODS

Transcriptomic data from OC patients and healthy controls (TCGA and GTEx) were analyzed to identify differentially expressed genes (DEGs) intersecting with metabolism-related (MRGs) and PCD-related genes (PCDRGs). Prognostic genes were determined using univariate Cox regression, LASSO, multivariate Cox regression, and stepwise analyses. Consensus clustering revealed enrichment differences, while a risk model and nomogram were developed for outcome prediction. Associations between prognostic genes, immune microenvironment, and drug sensitivity were also assessed.

RESULTS

A total of 166 candidate genes were identified, with PLA2G2D, LPCAT3, ARG1, PLA2G4A, and EXOSC3 emerging as significant prognostic markers. The risk model demonstrated marked survival differences, while the nomogram showed robust calibration for survival prediction. Differential immune cell infiltration was observed between risk groups. Additionally, Sinularin and Fulvestrant exhibited variable sensitivity, validated through molecular docking models.

CONCLUSION

Metabolism-related PCD genes were identified as pivotal prognostic markers in OC, providing critical insights for prognostic evaluation and targeted therapy development.

Targeting Wnt signaling in cancer drug resistance: Insights from pre-clinical and clinical research

Cancer drug resistance, encompassing both acquired and intrinsic chemoresistance, remains a significant challenge in the clinical management of tumors. While advancements in drug discovery and the development of various small molecules and anti-cancer compounds have improved patient responses to chemotherapy, the frequent and prolonged use of these drugs continues to pose a high risk of developing chemoresistance. Therefore, understanding the primary mechanisms underlying drug resistance is crucial. Wnt proteins, as secreted signaling molecules, play a pivotal role in transmitting signals from the cell surface to the nucleus. Aberrant expression of Wnt proteins has been observed in a variety of solid and hematological tumors, where they contribute to key processes such as proliferation, metastasis, stemness, and immune evasion, often acting in an oncogenic manner. Notably, the role of the Wnt signaling pathway in modulating chemotherapy response in human cancers has garnered significant attention. This review focuses on the involvement of Wnt signaling and its related molecular pathways in drug resistance, highlighting their associations with cancer hallmarks, stemness, and tumorigenesis linked to chemoresistance. Additionally, the overexpression of Wnt proteins has been shown to accelerate cancer drug resistance, with regulation mediated by non-coding RNAs. Elevated Wnt activity reduces cell death in cancers, particularly by affecting mechanisms like apoptosis, autophagy, and ferroptosis. Furthermore, pharmacological compounds and small molecules have demonstrated the potential to modulate Wnt signaling in cancer therapy. Given its impact, Wnt expression can also serve as a prognostic marker and a factor influencing survival outcomes in human cancers.

Targeting ferroptosis in gastrointestinal tumors: Interplay of iron-dependent cell death and autophagy

Ferroptosis is a regulated cell death mechanism distinct from apoptosis, autophagy, and necroptosis, marked by iron accumulation and lipid peroxidation. Since its identification in 2012, it has developed into a potential therapeutic target, especially concerning GI disorders like PC, HCC, GC, and CRC. This interest arises from the distinctive role of ferroptosis in the progression of diseases, presenting a new avenue for treatment where existing therapies fall short. Recent studies emphasize the promise of focusing on ferroptosis to fight GI cancers, showcasing its unique pathophysiological mechanisms compared to other types of cell death. By comprehending how ferroptosis aids in the onset and advancement of GI diseases, scientists aim to discover novel drug targets and treatment approaches. Investigating ferroptosis in gastrointestinal disorders reveals exciting possibilities for novel therapies, potentially revolutionizing cancer treatment and providing renewed hope for individuals affected by these tumors.

Molecular Insights in the Anticancer Activity of Natural Tocotrienols: Targeting Mitochondrial Metabolism and Cellular Redox Homeostasis

The role of mitochondria as the electric engine of cells is well established. Over the past two decades, accumulating evidence has pointed out that, despite the presence of a highly active glycolytic pathway (Warburg effect), a functional and even upregulated mitochondrial respiration occurs in cancer cells to meet the need of high energy and the biosynthetic demand to sustain their anabolic growth. Mitochondria are also the primary source of intracellular ROS. Cancer cells maintain moderate levels of ROS to promote tumorigenesis, metastasis, and drug resistance; indeed, once the cytotoxicity threshold is exceeded, ROS trigger oxidative damage, ultimately leading to cell death. Based on this, mitochondrial metabolic functions and ROS generation are considered attractive targets of synthetic and natural anticancer compounds. Tocotrienols (TTs), specifically the δ- and γ-TT isoforms, are vitamin E-derived biomolecules widely shown to possess striking anticancer properties since they regulate several intracellular molecular pathways. Herein, we provide for the first time an overview of the mitochondrial metabolic reprogramming and redox homeostasis perturbation occurring in cancer cells, highlighting their involvement in the anticancer properties of TTs. This evidence sheds light on the use of these natural compounds as a promising preventive or therapeutic approach for novel anticancer strategies.

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.

LncRNAs in modulating cancer cell resistance to paclitaxel (PTX) therapy

Paclitaxel (PTX) is widely used for treating several cancers, including breast, ovarian, lung, esophageal, gastric, pancreatic, and neck cancers. Despite its clinical utility, cancer recurrence frequently occurs in patients due to the development of resistance to PTX. Resistance mechanisms in cancer cells treated with PTX include alterations in β-tubulin, the target molecule involved in mitosis, activation of molecular pathways enabling drug efflux, and dysregulation of apoptosis-related proteins. Long non-coding RNAs (lncRNAs), which are RNA molecules longer than 200 nucleotides without protein-coding potential, serve diverse regulatory roles in cellular processes. Increasing evidence highlights the involvement of lncRNAs in cancer progression and their contribution to PTX resistance across various cancers. Consequently, lncRNAs have emerged as potential therapeutic targets for addressing drug resistance in cancer treatment. This review focuses on the current understanding of lncRNAs and their role in drug resistance mechanisms, aiming to encourage further investigation in this area. Key lncRNAs and their associated pathways linked to PTX resistance will be summarized.