Curcumin promotes cancer-associated fibroblasts apoptosis via ROS-mediated endoplasmic reticulum stress

Ferroptosis is involved in Staphylococcus aureus-induced mastitis through autophagy activation by endoplasmic reticulum stress

Cell death caused by severe Staphylococcus aureus (S. aureus) infection is a fatal threat to humans and animals. However, whether ferroptosis, an iron-dependent form of cell death, is involved in S. aureus-induced cell death and its role in S. aureus-induced diseases are unclear. Using a mouse mastitis model and mammary epithelial cells (MMECs), we investigated the role of ferroptosis in the pathogenesis of S. aureus infection. The results revealed that S. aureus-induced ferroptosis in vivo and in vitro as demonstrated by dose-dependent increases in cell death; the level of malondialdehyde (MDA), the final product of lipid peroxidation; and dose-dependent decrease the production of the antioxidant glutathione (GSH). Treatment with typical inhibitors of ferroptosis, including ferrostatin-1 (Fer-1) and deferiprone (DFO), significantly inhibited S. aureus-induced death in MMECs. Mechanistically, treatment with S. aureus activated the protein kinase RNA-like ER kinase (PERK)-eukaryotic initiation factor 2, α subunit (eIF2α)-activating transcription factor 4 (ATF4)-C/EBP homologous protein (CHOP) pathway, which subsequently upregulated autophagy and promoted S. aureus-induced ferroptosis. The activation of autophagy degraded ferritin, resulting in iron dysregulation and ferroptosis. In addition, we found that excessive reactive oxygen species (ROS) production induced ferroptosis and activated endoplasmic reticulum (ER) stress, manifesting as elevated p-PERK-p-eIF2α-ATF4-CHOP pathway protein levels. Collectively, our findings indicate that ferroptosis is involved in S. aureus-induced mastitis via ER stress-mediated autophagy activation, implying a potential strategy for the prevention of S. aureus-associated diseases by targeting ferroptosis. In conclusion, the ROS-ER stress-autophagy axis is involved in regulating S. aureus-induced ferroptosis in MMECs. These findings not only provide a new potential mechanism for mastitis induced by S. aureus but also provide a basis for the treatment of other ferroptotic-related diseases.

Cancer-associated fibroblasts and prostate cancer stem cells: crosstalk mechanisms and implications for disease progression

The functional heterogeneity and ecological niche of prostate cancer stem cells (PCSCs), which are major drivers of prostate cancer development and treatment resistance, have attracted considerable research attention. Cancer-associated fibroblasts (CAFs), which are crucial components of the tumor microenvironment (TME), substantially affect PCSC stemness. Additionally, CAFs promote PCSC growth and survival by releasing signaling molecules and modifying the surrounding environment. Conversely, PCSCs may affect the characteristics and behavior of CAFs by producing various molecules. This crosstalk mechanism is potentially crucial for prostate cancer progression and the development of treatment resistance. Using organoids to model the TME enables an in-depth study of CAF-PCSC interactions, providing a valuable preclinical tool to accurately evaluate potential target genes and design novel treatment strategies for prostate cancer. The objective of this review is to discuss the current research on the multilevel and multitarget regulatory mechanisms underlying CAF-PCSC interactions and crosstalk, aiming to inform therapeutic approaches that address challenges in prostate cancer treatment.

Targeting the pancreatic tumor microenvironment by plant-derived products and their nanoformulations

Pancreatic cancer remains a significant health issue with limited treatment options. The tumor stroma, a complex environment made up of different cells and proteins, plays a crucial role in tumor growth and chemoresistance. Targeting tumor stroma, consisting of diverse non-tumor cells such as fibroblasts, extracellular matrix (ECM), immune cells, and also pre-vascular cells is encouraging for remodeling solid cancers, such as pancreatic cancer. Remodeling the stroma of pancreas tumors can be suggested as a strategy for reducing resistance to chemo/immunotherapy. Several studies have shown that phytochemicals from plants can affect the tumor environment and have anti-cancer properties. By targeting key pathways involved in stromal activation, phytochemicals may disrupt communication between the tumor and stroma and make tumor cells more sensitive to different treatments. Additionally, phytochemicals have immunomodulatory and anti-angiogenic properties, all of which contribute to their potential in treating pancreatic cancer. This review will provide a detailed look at how phytochemicals impact the tumor stroma and their effects on pancreatic tumor growth, spread, and response to treatment. It will also explore the potential of combining phytochemicals with other treatment options like chemotherapy, immunotherapy, and radiation.

Targeting the prostate tumor microenvironment by plant-derived natural products

Prostate cancer is among the most common malignancies for men, with limited therapy options for last stages of the tumor. There are some different options for treatment and control of prostate tumor growth. However, targeting some specific molecules and cells within tumors has been attracted interests in recent years. The tumor microenvironment (TME) has an important role in the initiation of various malignancies, which can also expand the progression of tumor and facilitate invasion of malignant cells. By regulating immune responses and distinct changes in the metabolism of cells in the tumor, TME has substantial effects in the resistance of cancer cells to therapy. TME in various solid cancers like prostate cancer includes various cells, including cancer cells, supportive stromal cells, immunosuppressive cells, and anticancer inflammatory cells. Natural products including herbal-derived agents and also other natural compounds have been well studied for their anti-tumor potentials. These compounds may modulate various signaling pathways involved in TME, such as immune responses, the metabolism of cells, epigenetics, angiogenesis, and extracellular matrix (ECM). This paper provides a review of the current knowledge of prostate TME and complex interactions in this environment. Additionally, the potential use of natural products and also nanoparticles loaded with natural products as therapeutic adjuvants on different cells and therapeutic targets within prostate TME will be discussed.

Patulin induces ROS-dependent cardiac cell toxicity by inducing DNA damage and activating endoplasmic reticulum stress apoptotic pathway

Patulin (PAT) is one of the mycotoxins commonly found in agricultural products and fruits, and has obvious toxic effects on animals and humans. PAT has been found to cause myocardial toxicity and oxidative damage, but the mechanism of myocardial toxicity remained to be elucidated. We investigated the toxic effects and potential mechanisms of PAT on human cardiomyocytes and explored the effects of reactive oxygen species (ROS) on them. The study showed that treatment with PAT for 24 h decreased cell viability and superoxide dismutase (SOD) activity, and increased ROS and lactate dehydrogenase (LDH) levels. Moreover, in addition to detecting increased γ-H2AX expression and observing nuclear damage, the comet assay also showed increased DNA tail distance in the PAT-treated group, followed by an increase in phosphorylation of the p53 protein and p21 protein expression, and a decrease in CDK1 and Cyclin B1 protein expression, and G2/M phase arrest. In addition, PAT induced endoplasmic reticulum stress (ERS) and induced apoptosis, as evidenced by Ca2+ increase, ER enlargement and swelling, and upregulation of ERS-related genes and proteins expression, and increased expression of three apoptotic pathway proteins under ERS, including CHOP, JNK, and caspase-12. Meanwhile, N-acetylcysteine (NAC, a ROS scavenger) reversed the negative effects of PAT treatment on cells. These results clarify that excessive ROS production by PAT-treated AC16 cells not only causes DNA damage, leading to cell cycle arrest, but also causes ERS, which triggers apoptotic pathways to cause apoptosis.

Mechanism insights of curcumin and its analogues in cancer: An update

Cancer is the world's second leading cause of mortality and one of the major public health problems. Cancer incidence and mortality rates remain high despite the great advancements in existing therapeutic, diagnostic, and preventive approaches. Therefore, a quest for less toxic and more efficient anti-cancer strategies is still at the forefront of the current research. Traditionally important, curcumin commonly known as a wonder molecule has received considerable attention as an anti-cancer, anti-inflammatory, and antioxidant candidate. However, limited water solubility and low bioavailability restrict its extensive utility in different pathological states. The investigators are making consistent efforts to develop newer strategies to overcome its limitations by designing different analogues with better pharmacokinetic and pharmacodynamic properties. The present review highlights the recent updates on curcumin and its analogues with special emphasis on various mechanistic pathways involved in anti-cancer activity. In addition, the structure-activity relationship of curcumin analogues has also been precisely discussed. This article will also provide key information for the design and development of newer curcumin analogues with desired pharmacokinetic and pharmacodynamic profiles and will provide in depth understanding of molecular pathways involved in the anti-cancer activities.

Neutralizing tumor-related inflammation and reprogramming of cancer-associated fibroblasts by Curcumin in breast cancer therapy

Tumor-associated inflammation plays a vital role in cancer progression. Among the various stromal cells, cancer-associated fibroblasts are promising targets for cancer therapy. Several reports have indicated potent anti-inflammatory effects attributed to Curcumin. This study aimed to investigate whether inhibiting the inflammatory function of cancer-associated fibroblasts (CAFs) with Curcumin can restore anticancer immune responses. CAFs were isolated from breast cancer tissues, treated with Curcumin, and co-cultured with patients' PBMCs to evaluate gene expression and cytokine production alterations. Blood and breast tumor tissue samples were obtained from 12 breast cancer patients with stage II/III invasive ductal carcinoma. Fibroblast Activation Protein (FAP) + CAFs were extracted from tumor tissue, treated with 10 μM Curcumin, and co-cultured with corresponding PBMCs. The expression of smooth muscle actin-alpha (α-SMA), Cyclooxygenase-2(COX-2), production of PGE2, and immune cell cytokines were evaluated using Real-Time PCR and ELISA, respectively. Analyzes showed that treatment with Curcumin decreased the expression of genes α-SMA and COX-2 and the production of PGE2 in CAFs. In PBMCs co-cultured with Curcumin-treated CAFs, the expression of FoxP3 decreased along with the production of TGF-β, IL-10, and IL-4. An increase in IFN-γ production was observed that followed by increased T-bet expression. According to our results, Curcumin could reprogram the pro-tumor phenotype of CAFs and increase the anti-tumor phenotype in PBMCs. Thus, CAFs, as a component of the tumor microenvironment, are a suitable target for combination immunotherapies of breast cancer.

Microenvironmental regulation in tumor progression: Interactions between cancer-associated fibroblasts and immune cells

The tumor microenvironment (TME), the "soil" on which tumor cells grow, has an important role in regulating the proliferation and metastasis of tumor cells as well as their response to treatment. Cancer-associated fibroblasts (CAFs), as the most abundant stromal cells of the TME, can not only directly alter the immunosuppressive effect of the TME through their own metabolism, but also influence the aggregation and function of immune cells by secreting a large number of cytokines and chemokines, reducing the body's immune surveillance of tumor cells and making them more prone to immune escape. Our study provides a comprehensive review of fibroblast chemotaxis, malignant transformation, metabolic characteristics, and interactions with immune cells. In addition, the current small molecule drugs targeting CAFs have been summarized, including both natural small molecules and targeted drugs for current clinical therapeutic applications. A complete review of the role of fibroblasts in TME from an immune perspective is presented, which has important implications in improving the efficiency of immunotherapy by targeting fibroblasts.

Curcumin and analogues against head and neck cancer: From drug delivery to molecular mechanisms

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is one of the most life-threatening diseases which also causes economic burden worldwide. To overcome the limitations of traditional therapies, investigation into alternative adjuvant treatments is crucial.

PURPOSE

Curcumin, a turmeric-derived compound, demonstrates significant therapeutic potential in diverse diseases, including cancer. Furthermore, research focuses on curcumin analogues and novel drug delivery systems, offering approaches for improved efficacy. This review aims to provide a comprehensive overview of curcumin's current findings, emphasizing its mechanisms of anti-HNSCC effects and potential for clinical application.

METHOD

An electronic search of Web of Science, MEDLINE, and Embase was conducted to identify literature about the application of curcumin or analogues in HNSCC. Titles and abstracts were screened to identify potentially eligible studies. Full-text articles will be obtained and independently evaluated by two authors to make the decision of inclusion in the review.

RESULTS

Curcumin's clinical application is hindered by poor bioavailability, prompting the exploration of methods to enhance it, such as curcumin analogues and novel drug delivery systems. Curcumin could exhibit anti-cancer effects by targeting cancer cells and modulating the tumor microenvironment in HNSCC. Mechanisms of action include cell cycle arrest, apoptosis promotion, reactive oxygen species induction, endoplasmic reticulum stress, inhibition of epithelial-mesenchymal transition, attenuation of extracellular matrix degradation, and modulation of tumor metabolism in HNSCC cells. Curcumin also targets various components of the tumor microenvironment, including cancer-associated fibroblasts, innate and adaptive immunity, and lymphovascular niches. Furthermore, curcumin enhances the anti-cancer effects of other drugs as adjunctive therapy. Two clinical trials report its potential clinical applications in treating HNSCC.

CONCLUSION

Curcumin has demonstrated therapeutic potential in HNSCC through in vitro and in vivo studies. Its effectiveness is attributed to its ability to modulate cancer cells and interact with the intricate tumor microenvironment. The development of curcumin analogues and novel drug delivery systems has shown promise in improving its bioavailability, thereby expanding its clinical applications. Further research and exploration in this area hold great potential for harnessing the full therapeutic benefits of curcumin in HNSCC treatment.

Targeting extracellular matrix through phytochemicals: a promising approach of multi-step actions on the treatment and prevention of cancer

Extracellular matrix (ECM) plays a pivotal and dynamic role in the construction of tumor microenvironment (TME), becoming the focus in cancer research and treatment. Multiple cell signaling in ECM remodeling contribute to uncontrolled proliferation, metastasis, immune evasion and drug resistance of cancer. Targeting trilogy of ECM remodeling could be a new strategy during the early-, middle-, advanced-stages of cancer and overcoming drug resistance. Currently nearly 60% of the alternative anticancer drugs are derived from natural products or active ingredients or structural analogs isolated from plants. According to the characteristics of ECM, this manuscript proposes three phases of whole-process management of cancer, including prevention of cancer development in the early stage of cancer (Phase I); prevent the metastasis of tumor in the middle stage of cancer (Phase II); provide a novel method in the use of immunotherapy for advanced cancer (Phase III), and present novel insights on the contribution of natural products use as innovative strategies to exert anticancer effects by targeting components in ECM. Herein, we focus on trilogy of ECM remodeling and the interaction among ECM, cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs), and sort out the intervention effects of natural products on the ECM and related targets in the tumor progression, provide a reference for the development of new drugs against tumor metastasis and recurrence.

Curcumin derived from medicinal homologous foods: its main signals in immunoregulation of oxidative stress, inflammation, and apoptosis

It has been for thousands of years in China known medicinal homologous foods that can be employed both as foods and medicines to benefit human and animal health. These edible herbal materials perform divert roles in the regulation of metabolic disorders, cancers, and immune-related diseases. Curcumin, the primary component derived from medicinal homologous foods like curcuma longa rhizome, is reported to play vital actions in organic activities, such as the numerous pharmacological functions including anti-oxidative stress, anti-inflammation and anti/pro-apoptosis in treating various diseases. However, the potential mechanisms of curcumin-derived modulation still need to be developed and attract more attention worldwide. Given that these signal pathways are enrolled in important bioactive reactions, we collected curcumin's last achievements predominantly on the immune-regulation signals with the underlying targetable strategies in the last 10 years. This mini-review will be helpful to accelerate curcumin and other extracts from medicinal homologous foods use in future human clinical applications.

Curcumin activates a ROS/KEAP1/NRF2/miR-34a/b/c cascade to suppress colorectal cancer metastasis

Curcumin, a natural phytochemical isolated from tumeric roots, represents a candidate for prevention and therapy of colorectal cancer/CRC. However, the exact mechanism of action and the downstream mediators of curcumin's tumor suppressive effects have remained largely unknown. Here we used a genetic approach to determine the role of the p53/miR-34 pathway as mediator of the effects of curcumin. Three isogenic CRC cell lines rendered deficient for the p53, miR-34a and/or miR-34b/c genes were exposed to curcumin and subjected to cell biological analyses. siRNA-mediated inhibition and ectopic expression of NRF2, as well as Western blot, qPCR and qChIP analyses of its target genes were performed. CRC cells were i.v. injected into NOD/SCID mice and lung-metastases formation was determined by longitudinal, non-invasive imaging. In CRC cells curcumin induced apoptosis and senescence, and suppressed migration and invasion in a p53-independent manner. Curcumin activated the KEAP1/NRF2/ARE pathway by inducing ROS. Notably, curcumin induced miR-34a and miR-34b/c expression in a ROS/NRF2-dependent and p53-independent manner. NRF2 directly induced miR-34a and miR-34b/c via occupying multiple ARE motifs in their promoter regions. Curcumin reverted repression of miR-34a and miR-34b/c induced by IL6 and hypoxia. Deletion of miR-34a and miR-34b/c significantly reduced curcumin-induced apoptosis and senescence, and prevented the inhibition of migration and invasion by curcumin or ectopic NRF2. In CRC cells curcumin induced MET and prevented the formation of lung-metastases in mice in a miR-34a-dependent manner. In addition, we found that curcumin may enhance the therapeutic effects of 5-FU on CRC cells deficient for p53 and miR-34a/b/c. Activation of the KEAP1/NRF2/miR-34a/b/c axis mediates the tumor suppressive activity of curcumin and suggests a new approach for activating miR-34 genes in tumors for therapeutic purposes.

Nano-Based Drug Delivery of Polyphenolic Compounds for Cancer Treatment: Progress, Opportunities, and Challenges

Polyphenols and their derivates, a kind of natural product distributed in herb plants, vegetables, and fruits, are the most abundant antioxidants in the human diet and have been found to display cancer-preventative effects in several epidemiological studies. The scientific community has also validated the anti-cancer bioactivities and low toxicities of polyphenolic compounds, including flavones, tannins, phenolic acids, and anthocyanins, through in vitro and in vivo studies. However, the low stability, weak targeting ability, poor solubility, and low bioavailability of pure polyphenolic agents have significantly impaired their treatment efficacy. Nowadays, nano-based technology has been applied to surmount these restrictions and maximize the treatment efficacy of polyphenols. In this review, we summarize the advantages and related mechanisms of polyphenols in cancer treatment. Moreover, aiming at the poor solubility and low bioavailability of pure polyphenols in vivo, the advantages of nano-based delivery systems and recent research developments are highlighted. Herein, particular emphasis is mainly placed on the most widely used nanomaterials in the delivery of natural products, including liposomes, micelles, and nanogels. Finally, we present an overview and the challenges of future implementations of nano-based delivery systems of polyphenolic compounds in the cancer therapeutic field.

Remodeling tumor microenvironment with natural products to overcome drug resistance

With cancer incidence rates continuing to increase and occurrence of resistance in drug treatment, there is a pressing demand to find safer and more effective anticancer strategy for cancer patients. Natural products, have the advantage of low toxicity and multiple action targets, are always used in the treatment of cancer prevention in early stage and cancer supplement in late stage. Tumor microenvironment is necessary for cancer cells to survive and progression, and immune activation is a vital means for the tumor microenvironment to eliminate cancer cells. A number of studies have found that various natural products could target and regulate immune cells such as T cells, macrophages, mast cells as well as inflammatory cytokines in the tumor microenvironment. Natural products tuning the tumor microenvironment via various mechanisms to activate the immune response have immeasurable potential for cancer immunotherapy. In this review, it highlights the research findings related to natural products regulating immune responses against cancer, especially reveals the possibility of utilizing natural products to remodel the tumor microenvironment to overcome drug resistance.

Application and prospect of ROS-related nanomaterials for orthopaedic related diseases treatment

The importance of reactive oxygen species (ROS) in the occurrence and development of orthopaedic related diseases is becoming increasingly prominent. ROS regulation has become a new method to treat orthopaedic related diseases. In recent years, the application of nanomaterials has become a new hope for precision and efficient treatment. However, there is a lack of reviews on ROS-regulated nanomaterials for orthopaedic related diseases. Based on the key significance of nanomaterials for the treatment of orthopaedic related diseases, we searched the latest related studies and reviewed the nanomaterials that regulate ROS in the treatment of orthopaedic related diseases. According to the function of nanomaterials, we describe the scavenging of ROS related nanomaterials and the generation of ROS related nanomaterials. In this review, we closely integrated nanomaterials with the treatment of orthopaedic related diseases such as arthritis, osteoporosis, wound infection and osteosarcoma, etc., and highlighted the advantages and disadvantages of existing nanomaterials. We also looked forward to the design of ROS-regulated nanomaterials for the treatment of orthopaedic related diseases in the future.

Potential roles and molecular mechanisms of phytochemicals against cancer

Increasing evidence has been reported regarding phytochemicals, plant secondary metabolites, having therapeutic functions against numerous human diseases. Recently, phytochemicals (flavonoids, polyphenols, terpenoids, alkaloids, saponins, coumarins and so on) have shown promising anti-cancer efficacy with their distinct advantages of high efficiency and low toxicity. They regulate programmed cell death (apoptosis, pyroptosis, and autophagy), migration and senescence-related signaling pathways of cancer via the modulation of reactive oxygen species (ROS), mitogen activated protein kinase (MAPK) pathway, deleted in liver cancer 1 (DLC1), nuclear factor κ light-chain-enhancer of activated B cell (NF-κB) pathways and glycolytic enzymes. Here, we review the molecular mechanisms by which phytochemicals prevent the development of cancer. Furthermore, phytochemicals combined with chemotherapeutic agents could target the crosstalk among multiple signal cascades to block chemoresistance and attenuate carcinogenic properties, and can be considered as a novel and potential therapeutic strategy. Our review highlights that the mechanisms and promising applications are required to be understood to decisively establish the anti-cancer efficacy of natural phytochemicals.

Effects and Mechanisms of Curcumin for the Prevention and Management of Cancers: An Updated Review

Cancer is the leading cause of death in the world. Curcumin is the main ingredient in turmeric (Curcuma longa L.), and is widely used in the food industry. It shows anticancer properties on different types of cancers, and the underlying mechanisms of action include inhibiting cell proliferation, suppressing invasion and migration, promoting cell apoptosis, inducing autophagy, decreasing cancer stemness, increasing reactive oxygen species production, reducing inflammation, triggering ferroptosis, regulating gut microbiota, and adjuvant therapy. In addition, the anticancer action of curcumin is demonstrated in clinical trials. Moreover, the poor water solubility and low bioavailability of curcumin can be improved by a variety of nanotechnologies, which will promote its clinical effects. Furthermore, although curcumin shows some adverse effects, such as diarrhea and nausea, it is generally safe and tolerable. This paper is an updated review of the prevention and management of cancers by curcumin with a special attention to its mechanisms of action.

Small Molecules and Immunotherapy Agents for Enhancing Radiotherapy in Glioblastoma

Glioblastoma (GBM) is an aggressive primary brain tumor that is associated with a poor prognosis and quality of life. The standard of care has changed minimally over the past two decades and currently consists of surgery followed by radiotherapy (RT), concomitant and adjuvant temozolomide, and tumor treating fields (TTF). Factors such as tumor hypoxia and the presence of glioma stem cells contribute to the radioresistant nature of GBM. In this review, we discuss the current treatment modalities, mechanisms of radioresistance, and studies that have evaluated promising radiosensitizers. Specifically, we highlight small molecules and immunotherapy agents that have been studied in conjunction with RT in clinical trials. Recent preclinical studies involving GBM radiosensitizers are also discussed.

Microplastics and di (2-ethylhexyl) phthalate synergistically induce apoptosis in mouse pancreas through the GRP78/CHOP/Bcl-2 pathway activated by oxidative stress

With the widespread use of plastics, microplastics (MPs) and di(2-ethylhexyl) phthalate (DEHP) have become emerging environmental pollutants. The combined toxicity of MPs and DEHP on the mouse pancreas and the specific mechanism of toxicity remain unclear. To establish in vitro and in vivo models to address these questions, mice were continuously exposed to 200 mg/kg/d DEHP and 10 mg/L MPs for 4 weeks. In vitro, MIN-6 cells were treated with 200 μg/mL MPs and 200 μM DEHP for 24 h. Based on toxicity assessed using CCK8 of the equivalent TU binary mixture, the IC50 of the TU-mix of DEHP and MPs 0.692 < 0.8, indicating a synergistic effect of the two toxicants. Meanwhile, our data revealed that compared to the control group, MPs and DEHP combined treatment increased ROS levels, inhibited the activity, and enhanced the expression of GRP78, and CHOP. Simultaneously, activated CHOP decreased the expression of Bcl-2, and increased the expression of Bax. In conclusion, DEHP and MPs synergistically induce oxidative stress, and activate the GRP78/CHOP/Bcl-2 pathway to induce pancreatic apoptosis in mice. Our finding provides a new direction for the research on the specific mechanism of MPs and DEHP combined toxicity.

Curcuminoids as Modulators of EMT in Invasive Cancers: A Review of Molecular Targets With the Contribution of Malignant Mesothelioma Studies

Curcuminoids, which include natural acyclic diarylheptanoids and the synthetic analogs of curcumin, have considerable potential for fighting against all the characteristics of invasive cancers. The epithelial-to-mesenchymal transition (EMT) is a fundamental process for embryonic morphogenesis, however, the last decade has confirmed it orchestrates many features of cancer invasiveness, such as tumor cell stemness, metabolic rewiring, and drug resistance. A wealth of studies has revealed EMT in cancer is in fact driven by an increasing number of parameters, and thus understanding its complexity has now become a cornerstone for defining future therapeutic strategies dealing with cancer progression and metastasis. A specificity of curcuminoids is their ability to target multiple molecular targets, modulate several signaling pathways, modify tumor microenvironments and enhance the host’s immune response. Although the effects of curcumin on these various parameters have been the subject of many reviews, the role of curcuminoids against EMT in the context of cancer have never been reviewed so far. This review first provides an updated overview of all EMT drivers, including signaling pathways, transcription factors, non-coding RNAs (ncRNAs) and tumor microenvironment components, with a special focus on the most recent findings. Secondly, for each of these drivers the effects of curcumin/curcuminoids on specific molecular targets are analyzed. Finally, we address some common findings observed between data reported in the literature and the results of investigations we conducted on experimental malignant mesothelioma, a model of invasive cancer representing a useful tool for studies on EMT and cancer.

Preparation, Characterization, and In Vitro Release of Curcumin-Loaded IRMOF-10 Nanoparticles and Investigation of Their Pro-Apoptotic Effects on Human Hepatoma HepG2 Cells

Curcumin (CUR) has a bright future in the treatment of cancer as a natural active ingredient with great potential. However, curcumin has a low solubility, which limits its clinical application. In this study, IRMOF-10 was created by the direct addition of triethylamine, CUR was loaded into IRMOF-10 using the solvent adsorption method, and the two were characterized using a scanning electron microscope (SEM), X-ray diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG) methods, and Brunauer–Emmett–Teller (BET) analysis. We also used the MTT method, 4′,6-diamidino-2-phenylindole (DAPI) staining, the annexin V/PI method, cellular uptake, reactive oxygen species (ROS), and the mitochondrial membrane potential (MMP) to perform a safety analysis and anticancer activity study of IRMOF-10 and CUR@IRMOF-10 on HepG2 cells. Our results showed that CUR@IRMOF-10 had a CUR load of 63.96%, with an obvious slow-release phenomenon. The CUR levels released under different conditions at 60 h were 33.58% (pH 7.4) and 31.86% (pH 5.5). Cell experiments proved that IRMOF-10 was biologically safe and could promote curcumin entering the nucleus, causing a series of reactions, such as an increase in reactive oxygen species and a decrease in the mitochondrial membrane potential, thereby leading to cell apoptosis. In summary, IRMOF-10 is an excellent drug carrier and CUR@IRMOF-10 is an effective anti-liver cancer sustained-release preparation.

Curcumin and Related Compounds in Cancer Cells: New Avenues for Old Molecules

Curcumin and related compounds are known for the large spectrum of activities. The chemical features of these compounds are important for their biological effects with a key role for the thiol-reactive α−β unsaturated carbonyl groups. Curcumin derivatives may overcome the limitation of the bioavailability of the parent compound, while maintaining the key chemical features responsible for biological activities. Curcumin and related compounds show anti-viral, anti-fungal, anti-microbial and anti-tumor activities. The therapeutic effects of curcumin, used as a supplement in cancer therapy, have been documented in various cancer types, in which inhibition of cell growth and survival pathways, induction of apoptosis and other cell death pathways have been reported. Curcumin-induced apoptosis has been linked both to the intrinsic and extrinsic apoptotic pathways. Necroptosis has also been involved in curcumin-induced toxicity. Among curcumin-induced effects, ferroptosis has also been described. The mechanism of curcumin toxicity can be triggered by reactive oxygen species-mediated endoplasmic reticulum stress. Curcumin targets have been identified in the context of the ubiquitin-proteasome system with evidence of inhibition of the proteasome proteolytic activities and cellular deubiquitinases. Curcumin has recently been shown to act on the tumor microenvironment with effects on cancer-associated fibroblasts and immune cells. The related product caffeic acid phenethyl ester has shown promising preclinical results with an effect on the inflammatory microenvironment. Here, we review the mechanisms underlying curcumin and derivatives toxicity towards cancer cells with particular emphasis on cell death pathways and the ubiquitin-proteasome system.

Ligustilide Inhibits Tumor Angiogenesis by Downregulating VEGFA Secretion from Cancer-Associated Fibroblasts in Prostate Cancer via TLR4

CAFs secrete VEGFA in the tumor microenvironment to induce angiogenesis and promote tumor growth. The downregulation of VEGFA secretion from CAFs helps block angiogenesis and exerts an anti-tumor effect. In vivo experiments showed that the angiogenesis of the tumor-bearing mice in the ligustilide group was significantly reduced. The results of MTT, tube formation, Transwell and scratch experiments showed that ligustilide did not affect the proliferation of HUVECs in a certain concentration range (<60 μM), but it inhibited the proliferation, tube formation and migration of HUVECs induced by CAFs. At this concentration, ligustilide did not inhibit CAF proliferation. The qPCR and WB results revealed that ligustilide downregulated the level of VEGFA in CAFs via the TLR4-ERK/JNK/p38 signaling pathway, and the effect was attenuated by blockers of the above molecules. Ligustilide also downregulated the autocrine VEGFA of HUVECs induced by CAFs, which inhibited angiogenesis more effectively. In addition, ligustilide inhibited glycolysis and HIF-1 expression in CAFs. Overall, ligustilide downregulated the VEGFA level in CAFs via the TLR4-ERK/JNK/p38 signaling pathway and inhibited the promotion of angiogenesis. This study provides a new strategy for the anti-tumor effect of natural active molecules, namely, blockade of angiogenesis, and provides a new candidate molecule for blocking angiogenesis in the tumor microenvironment.

Construction of targeted delivery system for curcumin loaded on magnetic α-Fe2O3/Fe3O4 heterogeneous nanotubes and its apoptosis mechanism on MCF-7 cell

In this work, the magnetic α-Fe₂O₃/Fe₃O₄ heterogeneous nanotubes were successfully prepared by solvent hydrothermal-controlled calcination method. The effects of additive concentration, hydrothermal temperature and time on morphology of products were investigated. The α-Fe₂O₃/Fe₃O₄ nanotubes with a saturation magnetization of 50 emu/g were prepared calcinated at 600 °C for 4 h using 0.8 g of glucose. Their average length, the outer and inner diameters were around 240 nm, 178 nm and 145 nm, respectively. The α-Fe₂O₃/Fe₃O₄ heterogeneous nanotubes coated with water-soluble liposome were applied for targeted delivery of curcumin. The release of curcumin inside the hollow structure of the nanocomposites could be triggered and effectively sustained represented a process of slow release. The encapsulation efficiency of curcumin in the α-Fe₂O₃/Fe₃O₄-CUR@LIP nanocomposites reached 82.1 ± 0.9%. MTT assays demonstrated that blank carriers had excellent biocompatibility and application of magnetic field significantly elevated the cytotoxicity of α-Fe₂O₃/Fe₃O₄-CUR@LIP nanocomposites on MCF-7 cell. Electrochemical experiment and Prussian blue staining indicated that the α-Fe₂O₃/Fe₃O₄@LIP nanocomposites could aggregate in cells to promote the internalization of curcumin. Magnetic α-Fe₂O₃/Fe₃O₄-CUR@LIP nanocomposites and curcumin enhanced the expression of reactive oxygen species in MCF-7 cells and induced apoptosis by fluorescence detection. Flow cytometry and western blot verified that the α-Fe₂O₃/Fe₃O₄@LIP nanocomposites under magnetic field enhanced cells late-apoptosis by adjusting the expression of apoptosis-related proteins.

Hsa_circ_0056686, derived from cancer-associated fibroblasts, promotes cell proliferation and suppresses apoptosis in uterine leiomyoma through inhibiting endoplasmic reticulum stress

Abnormal expression of circular RNAs (circRNAs) in cancer-associated fibroblasts (CAFs) is involved in the tumor-promoting ability of CAFs. Hsa_ circ_ 0056686 has been reported to affect leiomyoma size. The purpose of this study is to investigate the regulatory role of hsa_circ_0056686 in CAFs on uterine leiomyoma (ULM). The primary CAFs and corresponding normal fibroblasts (NFs) were isolated from the tumor zones of ULM tissues and adjacent, respectively. Hsa_circ_0056686 level was higher in CAFs than NFs, and also higher in ULM tissues than in adjacent tissues. CAFs-CM significantly increased the proliferation and migration and inhibited apoptosis of ULM cells, as confirmed by CCK-8, transwell, and flow cytometry assays. Moreover, conditioned medium (CM) from CAFs transfected with hsa_circ_0056686 shRNA (CAFssh-circ_0056686-CM) abolished CAFs-mediated proliferation, migration and apoptosis of ULM cells. CAFs-CM suppressed the expression of endoplasmic reticulum stress (ERS) marker proteins and induced the expression of extracellular matrix (ECM) marker proteins, thus suppressing ERS and increasing ECM accumulation, which could be declined by CAFssh-circ_0056686-CM. Meanwhile, knockdown of hsa_circ_0056686 reversed the inhibitory effects of CAFs-CM on brefeldin A-induced cell apoptosis. Luciferase gene reporter and RNA pull-down assays indicated that miR-515-5p directly bound with hsa_circ_0056686. MiR-515-5p overexpression restored the hsa_circ_0056686-shRNA-mediated malignant biological behaviors of ULM cells. Hsa_circ_0056686 contributed to tumor-promoting effects of CAFs in ULM, manifested by promoting ULM cell proliferation and migration and reducing ERS-induced apoptosis through sponging miR-515-5p.

Natural Compounds Targeting Cancer-Associated Fibroblasts against Digestive System Tumor Progression: Therapeutic Insights

Cancer-associated fibroblasts (CAFs) are critical for cancer occurrence and progression in the tumor microenvironment (TME), due to their versatile roles in extracellular matrix remodeling, tumor–stroma crosstalk, immunomodulation, and angiogenesis. CAFs are the most abundant stromal component in the TME and undergo epigenetic modification and abnormal signaling cascade activation, such as transforming growth factor-β (TGF-β) and Wnt pathways that maintain the distinct phenotype of CAFs, which differs from normal fibroblasts. CAFs have been considered therapeutic targets due to their putative oncogenic functions. Current digestive system cancer treatment strategies often result in lower survival outcomes and fail to prevent cancer progression; therefore, comprehensive characterization of the tumor-promoting and -restraining CAF activities might facilitate the design of new therapeutic approaches. In this review, we summarize the enormous literature on natural compounds that mediate the crosstalk of CAFs with digestive system cancer cells, discuss how the biology and the multifaceted functions of CAFs contribute to cancer progression, and finally, pave the way for CAF-related antitumor therapies.

Radiosensitization and Radioprotection by Curcumin in Glioblastoma and Other Cancers

Radiation therapy plays an important role in almost every cancer treatment. However, radiation toxicity to normal tissues, mainly due to the generation of reactive free radicals, has limited the efficacy of radiotherapy in clinical practice. Curcumin has been reported to possess significant antitumor properties. Although curcumin can sensitize cancer cells to irradiation, healthy cells are much less sensitive to this effect, and thus, curcumin is thought to be a potent, yet safe anti-cancer agent. In this review, a summary of the role of curcumin as both a radiosensitizer and radioprotector has been presented, based on the most recent data from the experimental and clinical evaluation of curcumin in different cancer cell lines, animal models, and human patients.

Pharmacological Mechanisms and Clinical Applications of Curcumin: Update

Curcumin, a well-known hydrophobic polyphenol extracted from the rhizomes of turmeric (Curcuma longa L.), has attracted great interest in the last ten years due to its multiple pharmacological activities. A growing body of evidence has manifested that curcumin has extensive pharmacological activities including anti-inflammatory, anti-oxygenation, lipid regulation, antiviral, and anticancer with hypotoxicity and minor adverse reactions. However, the disadvantages of low bioavailability, short half-life in plasma, low drug concentration in blood, and poor oral absorption severely limited the clinical application of curcumin. Pharmaceutical researchers have carried out plenty of dosage form transformations to improve the druggability of curcumin and have achieved remarkable results. Therefore, the objective of this review summarizes the pharmacological research progress, problems in clinical application and the improvement methods of curcumin's druggability. By reviewing the latest research progress of curcumin, we believe that curcumin has a broad clinical application prospect for its wide range of pharmacological activities with few side effects. The deficiencies of lower bioavailability of curcumin could be improved by dosage form transformation. However, curcumin in the clinical application still requires further study regarding the underlying mechanism and clinical trial verification.

Circulating Tumour Cells (CTCs) in NSCLC: From Prognosis to Therapy Design

Designing optimal (neo)adjuvant therapy is a crucial aspect of the treatment of non-small-cell lung carcinoma (NSCLC). Standard methods of chemotherapy, radiotherapy, and immunotherapy represent effective strategies for treatment. However, in some cases with high metastatic activity and high levels of circulating tumour cells (CTCs), the efficacy of standard treatment methods is insufficient and results in treatment failure and reduced patient survival. CTCs are seen not only as an isolated phenomenon but also a key inherent part of the formation of metastasis and a key factor in cancer death. This review discusses the impact of NSCLC therapy strategies based on a meta-analysis of clinical studies. In addition, possible therapeutic strategies for repression when standard methods fail, such as the administration of low-toxicity natural anticancer agents targeting these phenomena (curcumin and flavonoids), are also discussed. These strategies are presented in the context of key mechanisms of tumour biology with a strong influence on CTC spread and metastasis (mechanisms related to tumour-associated and -infiltrating cells, epithelial–mesenchymal transition, and migration of cancer cells).

Targeting of the tumor microenvironment by curcumin

The tumor microenvironment (TME) is made up of several cells and molecules that affect the survival of cancer cells. Indeed, certain (immunosuppressive) cells which promote tumors can promote the growth of tumors by stimulating the proliferation of cancer cells and promoting angiogenesis. During tumor growth, antitumoral immunity includes natural killer cells and CD8+ T cells cannot overcome immunosuppressive responses and cancer cell proliferation. In order to achieve the appropriate therapeutic response, we must kill cancer cells and suppress the release of immunosuppressive molecules. The balance between anti-tumor immunity and immunosuppressive cells, such as regulatory T cells (Tregs), cancer-associated fibroblasts, tumor-associated macrophages, and myeloid-derived suppressor cells plays a key role in the suppression or promotion of cancer cells. Curcumin is a plant-derived agent that has shown interesting properties for cancer therapy. It has shown that not only directly inhibit the growth of cancer cells, but can also modulate the growth and activity of immunosuppressant and tumor-promoting cells. In this review, we explain how curcumin modulates interactions within TME in favor of tumor treatment. The potential modulating effects of curcumin on the responses of cancer cells to treatment modalities such as immunotherapy will also be discussed.

The Role of Curcumin in Cancer Treatment

Curcumin is a polyphenol extracted from the rhizomes of the turmeric plant, Curcuma longa which has anti-inflammatory, and anticancer properties. Chronic inflammation is associated with the development of cancer. Curcumin acts on the regulation of various immune modulators, including cytokines, cyclooxygenase-2 (COX-2), and reactive oxygen species (ROS), which partly explains its anticancer effects. It also takes part in the downregulation of growth factors, protein kinases, oncogenic molecules and various signaling pathways, such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), c-Jun N-terminal kinase (JNK) and signal transducer and activator of transcription 3 (STAT3) signaling. Clinical trials of curcumin have been completed or are ongoing for various types of cancer. This review presents the molecular mechanisms of curcumin in different types of cancer and the evidence from the most recent clinical trials.