Beneficial effects of the naturally occurring flavonoid silibinin on the prostate cancer microenvironment: role of monocyte chemotactic protein-1 and immune cell recruitment

Biomimetic "nano-spears" for CAFs-targeting: splintered three "shields" with enhanced cisplatin anti-TNBC efficiency

The treatment dilemma of triple-negative breast cancer (TNBC) revolves around drug resistance and metastasis. Cancer-associated fibroblasts (CAFs) contribute to cisplatin (Cis) resistance and further metastasis in TNBC, making TNBC a difficult-to-treat disease. The dense stromal barrier which restricts drug delivery, invasive phenotype of tumor cells, and immunosuppressive tumor microenvironment (TME) induced by CAFs serve as three "shields" for TNBC against Cis therapy. Here, we designed a silybin-loaded biomimetic nanoparticle coated with anisamide-modified red blood cell membrane (ARm@SNP) as a "nanospear" for CAFs-targeting, which could shatter the "shields" and significantly exhibit inhibitory effect on 4T1 cells in combination with Cis both in vitro and in vivo. The ARm@SNP/Cis elicited 4T1 tumor growth arrest and destroyed three "shields" as follows: disintegrating the stromal barrier by inhibiting blood vessels growth and the expression of fibronectin; decreasing 4T1 cell invasion and metastasis by affecting the TGF-β/Twist/EMT pathway which impeded EMT activation; reversing the immunosuppressive microenvironment by increasing the activity and infiltration of immunocompetent cells. Based on CAFs-targeting, ARm@SNP reversed the resistance of Cis, remodeled the TME and inhibited invasion and metastasis while significantly improving the therapeutic effect of Cis on 4T1 tumor-bearing mice, providing a promising approach for treating intractable TNBC.

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.

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.

Current Understanding of Flavonoids in Cancer Therapy and Prevention

Cancer is a major cause of death worldwide, with multiple pathophysiological manifestations. In particular, genetic abnormalities, inflammation, bad eating habits, radiation exposure, work stress, and toxin consumption have been linked to cancer disease development and progression. Recently, natural bioactive chemicals known as polyphenols found in plants were shown to have anticancer capabilities, destroying altered or malignant cells without harming normal cells. Flavonoids have demonstrated antioxidant, antiviral, anticancer, and anti-inflammatory effects. Flavonoid type, bioavailability, and possible method of action determine these biological actions. These low-cost pharmaceutical components have significant biological activities and are beneficial for several chronic disorders, including cancer. Recent research has focused primarily on isolating, synthesizing, and studying the effects of flavonoids on human health. Here we have attempted to summarize our current knowledge of flavonoids, focusing on their mode of action to better understand their effects on cancer.

Cold atmospheric plasma: Novel opportunities for tumor microenvironment targeting

With mounting preclinical and clinical evidences on the prominent roles of the tumor microenvironment (TME) played during carcinogenesis, the TME has been recognized and used as an important onco-therapeutic target during the past decade. Delineating our current knowledge on TME components and their functionalities can help us recognize novel onco-therapeutic opportunities and establish treatment modalities towards desirable anti-cancer outcome. By identifying and focusing on primary cellular components in the TME, that is, tumor-infiltrating lymphocytes, tumor-associated macrophages, cancer-associated fibroblasts and mesenchymal stem cells, we decomposed their primary functionalities during carcinogenesis, categorized current therapeutic approaches utilizing traits of these components, and forecasted possible benefits that cold atmospheric plasma, a redox modulating tool with selectivity against cancer cells, may convey by targeting the TME. Our insights may open a novel therapeutic avenue for cancer control taking advantages of redox homeostasis and immunostasis.

Flavonoids regulate tumor-associated macrophages - From structure-activity relationship to clinical potential (Review)

In recent years, the strategy for tumor therapy has changed from focusing on the direct killing effect of different types of therapeutic agents on cancer cells to the new mainstream of multi-mode and -pathway combined interventions in the microenvironment of the developing tumor. Flavonoids, with unique tricyclic structures, have diverse and extensive immunomodulatory and anti-cancer activities in the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are the most abundant immunosuppressive cells in the TME. The regulation of macrophages to fight cancer is a promising immunotherapeutic strategy. This study covers the most comprehensive cognition of flavonoids in regulating TAMs so far. Far more than a simple list of studies, we try to dig out evidence of crosstalk at the molecular level between flavonoids and TAMs from literature, in order to discuss the most relevant chemical structure and its possible relationship with the multimodal pharmacological activity, as well as systematically build a structure-activity relationship between flavonoids and TAMs. Additionally, we point out the advantages of the macro-control of flavonoids in the TME and discuss the potential clinical implications as well as areas for future research of flavonoids in regulating TAMs. These results will provide hopeful directions for the research of antitumor drugs, while providing new ideas for the pharmaceutical industry to develop more effective forms of flavonoids.

Modulation of TLR/NF-κB/NLRP Signaling by Bioactive Phytocompounds: A Promising Strategy to Augment Cancer Chemotherapy and Immunotherapy

Background

Tumors often progress to a more aggressive phenotype to resist drugs. Multiple dysregulated pathways are behind this tumor behavior which is known as cancer chemoresistance. Thus, there is an emerging need to discover pivotal signaling pathways involved in the resistance to chemotherapeutic agents and cancer immunotherapy. Reports indicate the critical role of the toll-like receptor (TLR)/nuclear factor-κB (NF-κB)/Nod-like receptor pyrin domain-containing (NLRP) pathway in cancer initiation, progression, and development. Therefore, targeting TLR/NF-κB/NLRP signaling is a promising strategy to augment cancer chemotherapy and immunotherapy and to combat chemoresistance. Considering the potential of phytochemicals in the regulation of multiple dysregulated pathways during cancer initiation, promotion, and progression, such compounds could be suitable candidates against cancer chemoresistance.

Objectives

This is the first comprehensive and systematic review regarding the role of phytochemicals in the mitigation of chemoresistance by regulating the TLR/NF-κB/NLRP signaling pathway in chemotherapy and immunotherapy.

Methods

A comprehensive and systematic review was designed based on Web of Science, PubMed, Scopus, and Cochrane electronic databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to include papers on TLR/NF-κB/NLRP and chemotherapy/immunotherapy/chemoresistance by phytochemicals.

Results

Phytochemicals are promising multi-targeting candidates against the TLR/NF-κB/NLRP signaling pathway and interconnected mediators. Employing phenolic compounds, alkaloids, terpenoids, and sulfur compounds could be a promising strategy for managing cancer chemoresistance through the modulation of the TLR/NF-κB/NLRP signaling pathway. Novel delivery systems of phytochemicals in cancer chemotherapy/immunotherapy are also highlighted.

Conclusion

Targeting TLR/NF-κB/NLRP signaling with bioactive phytocompounds reverses chemoresistance and improves the outcome for chemotherapy and immunotherapy in both preclinical and clinical stages.

Pro-inflammatory cytokines/chemokines, TNF-α, IL-6 and MCP-1, as biomarkers for the nephro- and pneumoprotective effect of silibinin after hepatic ischemia/reperfusion: confirmation by immunihistochemistry and qRT-PCR

The present study investigated the potential nephro- and pneumoprotective effect of silibinin (Si) after hepatic ischemia-reperfusion (I/R) injury, by measuring pro-inflammatory factors. Sixty-three rats were randomly assigned into three groups, as follows: (a) the sham group (n=7 rats), subjected to opening and closing the abdomen; (b) the control group (n = 28 rats), subjected to 45-min hepatic ischemia followed by reperfusion; and (c) the silibinin group (n=28), subjected to 45-min hepatic ischemia followed by intravenous administration of lyophilized SLB-HP-β-CD before reperfusion. Control and silibinin groups were further subdivided into time-point groups, according to the duration of reperfusion. TNF-α, IL-6 and MCP-1 expressions were determined immunihistochemically and by qrT-PCR at each time-point. Kidney TNF-α expression was significantly lower at 180 and 240 min, while lung TNF-α expression was significantly lower at 240 min. Comparison between the control and Si group at the same time-points, showed very strong evidence of difference at 240 min, with the levels of IL-6 shifting towards lower values in the Si group. Finally, we found a high MCP-1 expression after 120 min. We conclude that hepatic I/R injury remotely increases proinflammatory mediators in the kidney and lung, whereas silibinin shows a time-dependent nephro- and pneumoprotective effect.

Flavonoids against non-physiologic inflammation attributed to cancer initiation, development, and progression—3PM pathways

Inflammation is an essential pillar of the immune defense. On the other hand, chronic inflammation is considered a hallmark of cancer initiation and progression. Chronic inflammation demonstrates a potential to induce complex changes at molecular, cellular, and organ levels including but not restricted to the stagnation and impairment of healing processes, uncontrolled production of aggressive ROS/RNS, triggered DNA mutations and damage, compromised efficacy of the DNA repair machinery, significantly upregulated cytokine/chemokine release and associated patho-physiologic protein synthesis, activated signaling pathways involved in carcinogenesis and tumor progression, abnormal tissue remodeling, and created pre-metastatic niches, among others. The anti-inflammatory activities of flavonoids demonstrate clinically relevant potential as preventive and therapeutic agents to improve individual outcomes in diseases linked to the low-grade systemic and chronic inflammation, including cancers. To this end, flavonoids are potent modulators of pro-inflammatory gene expression being, therefore, of great interest as agents selectively suppressing molecular targets within pro-inflammatory pathways. This paper provides in-depth analysis of anti-inflammatory properties of flavonoids, highlights corresponding mechanisms and targeted molecular pathways, and proposes potential treatment models for multi-level cancer prevention in the framework of predictive, preventive, and personalized medicine (PPPM / 3PM). To this end, individualized profiling and patient stratification are essential for implementing targeted anti-inflammatory approaches. Most prominent examples are presented for the proposed application of flavonoid-conducted anti-inflammatory treatments in overall cancer management.

Molecular Basis of Prostate Cancer and Natural Products as Potential Chemotherapeutic and Chemopreventive Agents

Prostate cancer is the second most common malignant cancer in males. It involves a complex process driven by diverse molecular pathways that closely related to the survival, apoptosis, metabolic and metastatic characteristics of aggressive cancer. Prostate cancer can be categorized into androgen dependent prostate cancer and castration-resistant prostate cancer and cure remains elusive due to the developed resistance of the disease. Natural compounds represent an extraordinary resource of structural scaffolds with high diversity that can offer promising chemical agents for making prostate cancer less devastating and curable. Herein, those natural compounds of different origins and structures with potential cytotoxicity and/or in vivo anti-tumor activities against prostate cancer are critically reviewed and summarized according to the cellular signaling pathways they interfere. Moreover, the anti-prostate cancer efficacy of many nutrients, medicinal plant extracts and Chinese medical formulations were presented, and the future prospects for the application of these compounds and extracts were discussed. Although the failure of conventional chemotherapy as well as involved serious side effects makes natural products ideal candidates for the treatment of prostate cancer, more investigations of preclinical and even clinical studies are necessary to make use of these medical substances reasonably. Therefore, the elucidation of structure-activity relationship and precise mechanism of action, identification of novel potential molecular targets, and optimization of drug combination are essential in natural medicine research and development.

Targeting phytoprotection in the COVID-19-induced lung damage and associated systemic effects-the evidence-based 3PM proposition to mitigate individual risks

The risks related to the COVID-19 are multi-faceted including but by far not restricted to the following: direct health risks by poorly understood effects of COVID-19 infection, overloaded capacities of healthcare units, restricted and slowed down care of patients with non-communicable disorders such as cancer, neurologic and cardiovascular pathologies, among others; social risks-restricted and broken social contacts, isolation, professional disruption, explosion of aggression in the society, violence in the familial environment; mental risks-loneliness, helplessness, defenceless, depressions; and economic risks-slowed down industrial productivity, broken delivery chains, unemployment, bankrupted SMEs, inflation, decreased capacity of the state to perform socially important programs and to support socio-economically weak subgroups in the population. Directly or indirectly, the above listed risks will get reflected in a healthcare occupation and workload which is a tremendous long-term challenge for the healthcare capacity and robustness. The article does not pretend to provide solutions for all kind of health risks. However, it aims to present the scientific evidence of great clinical utility for primary, secondary, and tertiary care to protect affected individuals in a cost-effective manner. To this end, due to pronounced antimicrobial, antioxidant, anti-inflammatory, and antiviral properties, naturally occurring plant substances are capable to protect affected individuals against COVID-19-associated life-threatening complications such as lung damage. Furthermore, they can be highly effective, if being applied to secondary and tertiary care of noncommunicable diseases under pandemic condition. Thus, the stratification of patients evaluating specific health conditions such as sleep quality, periodontitis, smoking, chronic inflammation and diseases, metabolic disorders and obesity, vascular dysfunction, and cancers would enable effective managemenet of COVID-19-associated complications in primary, secondary, and tertiary care in the context of predictive, preventive, and personalized medicine (3PM).

pH-Sensitive PEGylated Liposomal Silybin: Synthesis, In Vitro and In Vivo Anti-Tumor Evaluation

The drug delivery systems improve the efficacy of chemotherapeutics through enhanced targeting and controlled release however, biological barriers of tumor microenvironment greatly impede the penetration of nanomedicine within the tumor. We report herein the fabrication of a PEG-detachable silybin (SLB) pH-sensitive liposome decorated with TAT-peptide. For this, Acyl hydrazide-activated PEG₂₀₀₀ was prepared and linked with ketone-derivatized DPPE via an acid-labile hydrazone bond to form mPEG₂₀₀₀-HZ-DPPE. TAT peptide was conjugated with a shorter -PEG₁₀₀₀-DSPE spacer and post-inserted into PEGylated liposome (DPPC: mPEG₂₀₀₀-DSPE: Chol). To prepare nanoliposomes (around 100 nm), first, a novel method was used to prepare SLB-Soya PC (SLB-SPC) complex, then this complex was incorporated into nanoliposomes. The pH-sensitivity and shielding effect of long PEG chain on TAT peptide was investigated using DiI liposome and FACS analysis. Pre-treatment to the lowered pH enhanced cellular association of TAT-modified pH-sensitive liposome due to the cleavage of hydrazone bond and TAT exposure. Besides, TAT-modified pH-sensitive liposomes significantly reduced cell viability compared to the plain liposome. In vivo results were very promising with pH-sensitive liposome by detaching PEG moieties upon exposure to the acidic tumor microenvironment, enhancing cellular uptake, retarding tumor growth, and prolonging the survival of 4T1 breast tumor-bearing BALB/c mice. TAT modification of pH-sensitive liposome improved cancer cell association and cytotoxicity and demonstrated potential intracellular delivery upon exposure to acidic pH. However, in in vivo studies, TAT as a targeting ligand significantly decreased the therapeutic efficacy of the formulation attributed to an inefficient tumor accumulation and higher release rate in the circulation. The results of this study indicated that pH-sensitive liposome containing SLB, which was prepared with a novel method with a significant SLB loading efficiency, is very effective in the treatment of 4T1 breast tumor-bearing BALB/c mice and merits further investigation.

Molecular insights into phytochemicals-driven break function in tumor microenvironment

Advanced knowledge about the role of tumor microenvironment (TME) in cancer progression has opened various ways to target the vast signaling pathways for cancer treatment. Failures of the currently used drugs have raised out the need to look for novel drugs which can target various crucial aspects of cancer progression (e.g., angiogenesis, uncontrolled cell division, and metastasis). Phytochemicals behaving as potent anticancer agents shows promise as therapeutics. Various phytochemicals, such as curcumin, Epigallocatechin Gallate (EGCG), resveratrol, plumbagin, genistein, and others, have been identified with modulatory effect on TME. These phytochemicals often target the molecular pathways that reside in the tumor vicinity associated with endothelial cells, cancer-associated fibroblasts, immune cells, mesenchymal stem cells, other cell types, vascular and lymphatic networks, and extracellular matrix which are important for tumor progression and development. Some phytochemicals also target the internal signaling pathways, including STAT3, NF-қB, ERK-1/2, and PI3K/Akt signaling of noncancer cell, residing in the microenvironment, and thus inhibiting the supportive effect from these cells in tumor development. However, much information needs to be acquired before using these phytochemicals in cancer treatment. The primary objective of this review is to provide a better knowledge about the role of TME in cancer progression and development, focusing on the different targets which can be used for therapeutic approach, and then to give a brief account on some known phytochemicals to date, which have shown remarkable TME modulatory effects. PRACTICAL APPLICATIONS: For the use of phytochemicals as therapeutics, it is highly recommended that their precise target should be known; therefore studies should be encouraged such that the effects of these phytochemicals can be evaluated on the individual cellular level like how the phytochemical is targeting the tumor-associated macrophage, or any other cell residing in the tumor microenvironment (TME), and the compound should target a specific component of TME to avoid off target effects.

Identification of key genes in the tumor microenvironment of lung adenocarcinoma

The tumor microenvironment plays an important role in tumor development and progression, but the role of immune and stromal cells in this environment has not been sufficiently studied. In this study, we aimed to identify key genes associated with the microenvironment of lung adenocarcinoma (LUAD). Raw data for stromal and immune cells in malignant tumors were downloaded from The Cancer Genome Atlas (TCGA). These expression data were used to identify the differentially expressed genes (DEGs) in tissue samples of LUAD with high and low immune scores. A protein-protein interaction (PPI) network based on genes with significant differential expression was constructed. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to functionally annotate putative hub genes. These genes were assessed via Kaplan Meier analysis to determine their correlation with overall survival. In total, we identified 216 DEGs which were correlated with immune and stromal scores, including 30 hub genes which were identified based on the PPI network. Further analysis suggested that the expression levels of 10 of these genes were significantly correlated with overall survival of LUAD patients. These key hub genes included CCR2, CCR5, CD53, CYBB, HCK, IRF8, LCP2, PLEK, PTPRC, and TLR7. Moreover, the expression level of CCR2 was found to have strong prognostic value for LUAD patients. Additionally, high expression of CYBB was also correlated with better survival of patients with LUAD. The results of this study open several new avenues to explore in the treatment of LUAD.

Immune Checkpoint Inhibitors: A Promising Treatment Option for Metastatic Castration-Resistant Prostate Cancer?

Since 2010, several treatment options have been available for men with metastatic castration-resistant prostate cancer (mCRPC), including immunotherapeutic agents, although the clinical benefit of these agents remains inconclusive in unselected mCRPC patients. In recent years, however, immunotherapy has re-emerged as a promising therapeutic option to stimulate antitumor immunity, particularly with the use of immune checkpoint inhibitors (ICIs), such as PD-1/PD-L1 and CTLA-4 inhibitors. There is increasing evidence that ICIs may be especially beneficial in specific subgroups of patients with high PD-L1 tumor expression, high tumor mutational burden, or tumors with high microsatellite instability/mismatch repair deficiency. If we are to improve the efficacy of ICIs, it is crucial to have a better understanding of the mechanisms of resistance to ICIs and to identify predictive biomarkers to determine which patients are most likely to benefit. This review focuses on the current status of ICIs for the treatment of mCRPC (either as monotherapy or in combination with other drugs), mechanisms of resistance, potential predictive biomarkers, and future challenges in the management of mCRPC.

Proteomics reveals the function reverse of MPSSS-treated prostate cancer-associated fibroblasts to suppress PC-3 cell viability via the FoxO pathway

Prostate cancer‐associated fibroblasts (prostate CAFs) are essential components of the tumor microenvironment and can promote tumor progression through their immunosuppressive functions. MPSSS, a novel polysaccharide purified from Lentinus edodes, has been reported to have anti‐tumor activity. MPSSS could also inhibit the immunosuppressive function of prostate CAFs, which has been demonstrated through that the secretome of MPSSS‐treated prostate CAFs could inhibit the proliferation of T cells. However, how the secretome of MPSSS‐treated prostate CAFs influence prostate cancer progression is still unclear. Interestingly, we found that the low molecular weight (3–100kD) secretome of prostate CAFs (lmwCAFS) could promote the growth of PC‐3 cells, while that of MPSSS‐treated prostate CAFs (MT‐lmwCAFS) could inhibit their growth. We carried out comparative secretomic analysis of lmwCAFS and MT‐lmwCAFS to identify functional molecules that inhibit the growth of PC‐3 cells, and proteomic analysis of lmwCAFS‐treated PC‐3 cells and MT‐lmwCAFS‐treated PC‐3 cells to investigate the underlying molecular mechanism. These analyses suggest that TGF‐β3 from MT‐lmwCAFS may inhibit the growth of PC‐3 cells. The validated experiments revealed that TGF‐β3 from MT‐lmwCAFS activated p21 expression in PC‐3 cells by regulating the FoxO pathway thereby inducing G0/G1 cell cycle arrest of PC‐3 cells. Overall, our data demonstrated that MPSSS reversed the ability of prostate CAFs to suppress the cell viability of PC‐3 cells, which might provide a potential therapeutic strategy to prevent prostate cancer progression.

Natural products remodel cancer-associated fibroblasts in desmoplastic tumors

Desmoplastic tumors have an abundance of stromal cells and the extracellular matrix which usually result in therapeutic resistance. Current treatment prescriptions for desmoplastic tumors are usually not sufficient to eliminate the malignancy. Recently, through modulating cancer-associated fibroblasts (CAFs) which are the most abundant cell type among all stromal cells, natural products have improved chemotherapies and the delivery of nanomedicines to the tumor cells, showing promising ability to improve treatment effects on desmoplastic tumors. In this review, we discussed the latest advances in inhibiting desmoplastic tumors by modeling CAFs using natural products, highlighting the potential therapeutic abilities of natural products in targeting CAFs for cancer treatment.

Nanomedicines modulating tumor immunosuppressive cells to enhance cancer immunotherapy

Cancer immunotherapy has veered the paradigm of cancer treatment. Despite recent advances in immunotherapy for improved antitumor efficacy, the complicated tumor microenvironment (TME) is highly immunosuppressive, yielding both astounding and unsatisfactory clinical successes. In this regard, clinical outcomes of currently available immunotherapy are confined to the varied immune systems owing in large part to the lack of understanding of the complexity and diversity of the immune context of the TME. Various advanced designs of nanomedicines could still not fully surmount the delivery barriers of the TME. The immunosuppressive TME may even dampen the efficacy of antitumor immunity. Recently, some nanotechnology-related strategies have been inaugurated to modulate the immunosuppressive cells within the tumor immune microenvironment (TIME) for robust immunotherapeutic responses. In this review, we will highlight the current understanding of the immunosuppressive TIME and identify disparate subclasses of TIME that possess an impact on immunotherapy, especially those unique classes associated with the immunosuppressive effect. The immunoregulatory cell types inside the immunosuppressive TIME will be delineated along with the existing and potential approaches for immunosuppressive cell modulation. After introducing the various strategies, we will ultimately outline both the novel therapeutic targets and the potential issues that affect the efficacy of TIME-based nanomedicines.

Anticancer activities of phytoconstituents and their liposomal targeting strategies against tumor cells and the microenvironment

Various bioactive ingredients have been extracted from Chinese herbal medicines (CHMs) that affect tumor progression and metastasis. To further understand the mechanisms of CHMs in cancer therapy, this article summarizes the effects of five categories of CHMs and their active ingredients on tumor cells and the tumor microenvironment. Despite their treatment potential, the undesirable physicochemical properties (poor permeability, instability, high hydrophilicity or hydrophobicity, toxicity) and unwanted pharmacokinetic profiles (short half-life in blood and low bioavailability) restrict clinical studies of CHMs. Therefore, development of liposomes through relevant surface modifying techniques to achieve targeted CHM delivery for cancer cells, i.e., extracellular and intracellular targets and targets in tumor microenvironment or vasculature, have been reviewed. Current challenges of liposomal targeting of these phytoconstituents and future perspective of CHM applications are discussed to provide an informative reference for interested readers.

Silibinin inhibits epithelial‑mesenchymal transition of renal cell carcinoma through autophagy‑dependent Wnt/β‑catenin signaling

Silibinin is a flavonoid extracted from milk thistle seeds which has been widely used as a hepatoprotective and antioxidant agent. Recently, accumulating evidence has demonstrated the anti-cancer effects of silibinin in various cancer models. It was previously reported that silibinin induced apoptosis and decreased metastasis by activating autophagy in renal cell carcinoma (RCC). However, the underlying molecular mechanisms by which silibinin regulates autophagy remain largely unknown. The aim of the present study was to investigate the effects of silibinin on RCC metastasis in vitro and in vivo, with a focus on autophagy-dependent Wnt/β-catenin signaling. Human RCC 786-O and ACHN cell lines were used as the model system in vitro and RCC xenografts of nude mice were used for in vivo studies. Silibinin inhibited metastasis and epithelial-mesenchymal transition (EMT) of RCC in vitro and in vivo, by regulating the Wnt/β-catenin signaling pathway. Furthermore, silibinin inhibited the Wnt/β-catenin signaling pathway in an autophagy-dependent manner. Autophagic degradation of β-catenin induced by silibinin was associated with the anti-metastatic effects of silibinin against RCC. These findings identify a novel mechanism by which silibinin inhibits EMT and metastasis of RCC, highlighting a potential novel strategy for treating metastatic RCC.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

Silymarin antiproliferative and apoptotic effects: Insights into its clinical impact in various types of cancer

Silymarin is a complex extract isolated from the plant Silybum marianum, widely known for its prominent antioxidant and hepatoprotective effects, although increasing evidences have reported extraordinary antiproliferative and apoptotic abilities. As a result, several signaling pathways involved in cell cycle control, cell proliferation, and cell death have been deconvoluted as critical mechanisms. In this regard, cyclin and cyclin-dependent pathways have been the most studied ones. Following that, apoptotic pathways, such as p53, Akt, STAT-3, Ras, and caspases pathways, have been extensively studied, although other mechanisms involved in inflammation and angiogenesis have also been highlighted as silymarin-likely targets in cancer therapy. Therefore, the main challenge of this review is to discuss the diverse molecular mechanisms for silymarin antiproliferative and apoptotic effects; most of them largely studied in various types of cancers so far. Clinical trials and combination therapies related to silymarin application in cancer prevention and treatment are presented as well.

Crosstalk between cancer-associated fibroblasts and immune cells in cancer

Multiple studies have shown that cancer‐associated fibroblasts (CAFs) play an important role in tumour progression, including carcinogenesis, invasion, metastasis and the chemoresistance of cancer cells. Immune cells, including macrophages, natural killer cells, dendritic cells and T cells, play a dual role in the tumour microenvironment. Although increasing research has focused on studying interactions between distinct cells in the tumour microenvironment, the complex relationships between CAFs and immune cells remain unclear and need further study. Here, we summarize our current understanding of crosstalk between CAFs and immune cells, which may help clarify their diagnostic and therapeutic value in tumour progression.

Silibinin Differentially Decreases the Aggressive Cancer Phenotype in an In Vitro Model of Obesity and Prostate Cancer

Aim: Obesity increases the risk for aggressive and fatal prostate cancer (PCa). The bioactive compound silibinin has been researched for its chemopreventative properties and may benefit obese or overweight individuals with PCa.Methods: This study used an in vitro model of obesity exposing prostate cancer cells to sera from obese, overweight, or normal weight males with or without the addition of silibinin. Molecular activity was assayed as well as the phenotype of PCa cells with various treatments.Results: Obesity increased the expression of proliferative signaling including COX-2, IL-6, AKT, ERK, and AR, which was attenuated with silibinin. Cell growth, and invasive capacity of prostate cancer cells was increased with obese and overweight sera, and silibinin was able to mitigate this affect. However, there are limitations to this study in that an in vivo model was not used to validate these in vitro results nor a co-culture model, which may better recapitulate the tumor microenvironment.Conclusions: Silibinin may be a safe intervention for those with or at risk for prostate cancer, and it may be the most beneficial for obese or overweight males.

Dietary Flavonoids for Immunoregulation and Cancer: Food Design for Targeting Disease

Flavonoids, one of the most abundant phytochemicals in a diet rich in fruits and vegetables, have been recognized as possessing anti-proliferative, antioxidant, anti-inflammatory, and estrogenic activities. Numerous cellular and animal-based studies show that flavonoids can function as antioxidants by preventing DNA damage and scavenging reactive oxygen radicals, inhibiting formation of DNA adducts, enhancing DNA repair, interfering with chemical damage by induction of Phase II enzymes, and modifying signaling pathways. Recent evidence also shows their ability to regulate the immune system. However, findings from clinical trials have been mixed with no clear consensus on dose, frequency, or type of flavonoids best suited to elicit many of the beneficial effects. Delivery of these bioactive compounds to their biological targets through "targeted designed" food processing strategies is critical to reach effective concentration in vivo. Thus, the identification of novel approaches that optimize flavonoid bioavailability is essential for their successful clinical application. In this review, we discuss the relevance of increasing flavonoid bioavailability, by agricultural engineering and "targeted food design" in the context of the immune system and cancer.

Traditional Chinese medicine as a cancer treatment: Modern perspectives of ancient but advanced science

Traditional Chinese medicine (TCM) has been practiced for thousands of years and at the present time is widely accepted as an alternative treatment for cancer. In this review, we sought to summarize the molecular and cellular mechanisms underlying the chemopreventive and therapeutic activity of TCM, especially that of the Chinese herbal medicine-derived phytochemicals curcumin, resveratrol, and berberine. Numerous genes have been reported to be involved when using TCM treatments and so we have selectively highlighted the role of a number of oncogene and tumor suppressor genes in TCM therapy. In addition, the impact of TCM treatment on DNA methylation, histone modification, and the regulation of noncoding RNAs is discussed. Furthermore, we have highlighted studies of TCM therapy that modulate the tumor microenvironment and eliminate cancer stem cells. The information compiled in this review will serve as a solid foundation to formulate hypotheses for future studies on TCM-based cancer therapy.

Mechanism of modulation through PI3K-AKT pathway about Nepeta cataria L.'s extract in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is regarded as one of the major intractable diseases, which was cured mainly by chemotherapeutics in the clinical treatment at present. But it is still a vital mission for the current medical and researchers that hunting a natural medicine which have little side effects and high-efficiency against the NSCLC on account of the shortcomings on current drugs. Nepeta cataria L. plays an important role in anti-cancer treatment according to the reports which was recorded in the Chinese Pharmacopoeia of version 2015 and belongs to one of the Traditional Chinese medicine (TCM). Microfluidic chip technology is widely used in scientific research field due to its high-throughput, high sensitivity and low cost with the continuous progress of science and technology. In this study, we investigate the effect of total flavonoid extracted from Nepeta cataria L. (TFS) through human lung cancer cell line A549 based on the microfluidic device and Flow Cytometry. So we detected the mRNA expression of MicroRNA-126 (miR-126), VEGF, PI3K, PTEN and proteins expression respectively to explore the partial PI3K-AKT pathway molecular mechanisms through Quantitative Real-time PCR (qRT-PCR) and Western Blot. The results showed that TFS can disturb the expression of miR-126 and regulate the PI3K-AKT signaling pathway to meet the effect of anti-cancer. Taking all these results into consideration we can draw a conclusion that TFS may be used as a novel therapeutic agent for NSCLC in the near future.

Silibinin alleviates inflammation and induces apoptosis in human rheumatoid arthritis fibroblast-like synoviocytes and has a therapeutic effect on arthritis in rats

Silibinin, a natural polyphenolic flavonoid, possesses anti-oxidant, anti-inflammation and anti-cancer properties. The present study was designed to investigate the effects of silibinin on rheumatoid arthritis (RA) pathogenesis-related cells and collagen-induced arthritis (CIA) and further explore the potential underlying mechanisms. Our results showed that silibinin suppressed cell viability and increased the percentage of apoptotic RA-fibroblast-like synoviocytes (FLS). Furthermore, the production of inflammatory cytokines in RA-FLS and a CIA rat model was effectively inhibited by silibinin. Silibinin also induced macrophage M2 polarization in RAW264.7 cells. We further demonstrated that silibinin inhibits Th17 cell differentiation in vitro. The nuclear factor kappa B (NF-κB) pathway was suppressed in RA-FLS. In addition, Sirtuin1 (SIRT1) was decreased after silibinin treatment, and RA-FLS transfection with a short hairpin RNA (shRNA) of SIRT1 enhanced silibinin-induced apoptosis. Autophagy was markedly decreased in a dose-dependent manner following silibinin treatment. These findings indicate that silibinin inhibited inflammation by inhibiting the NF-κB pathway, and SIRT1 may participate in silibinin-induced apoptosis. Silibinin also inhibited autophagy in RA-FLS. Thus, silibinin may be a potential therapeutic agent for the treatment of RA.

Inhibitory effect of silymarin on CCl4-induced liver fibrosis by reducing Ly6Chi monocytes infiltration

It has been well established that silymarin has hepatoprotective and anti-fibrotic effects. But the mechanisms are poorly understood. In recent years, the role of Ly6C^hi monocytes in liver fibrosis has been well demonstrated. Thus, in present study we aimed to investigate whether silymarin can relieve liver fibrosis by reducing Ly6C^hi monocytes infiltration. The mouse model of liver fibrosis was established by injected with carbon tetrachloride (CCl₄) via intraperitoneal repeatedly. Mice in silymarin group received silymarin treatment by gavage. Silymarin significantly reduced liver inflammation and fibrosis of the mice induced by CCl₄ injection, as revealed by liver histological and pathological analysis. Mice administrated by silymarin exhibited less infiltration of Ly6C^hi monocytes. But there was no difference on other tested leukocyte subsets between CCl₄ group and silymarin group. Meanwhile, further study found that silymarin significantly reduced CCl₄-induced increased expression of tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β1 and monocyte chemoattractant protein 1 (MCP-1), which was in line with the decreased numbers of intrahepatic Ly6C^hi monocytes. In conclusion, our study showed that the anti-inflammatory and anti-fibrotic effects of silymarin could be contributed to the prevention of Ly6C^hi monocytes infiltration into the injured livers, which will give us a better understanding on the cellular mechanism of hepatoprotective and anti-fibrotic effect for silymarin.

An update of research evidence on nutrition and prostate cancer

BACKGROUND

Prostate cancer (PCa) remains a leading cause of mortality in US and other countries. Preclinical and clinical studies have examined the role of nutrition and dietary intake on the incidence and progression of PCa with mixed results.

OBJECTIVE

The objective of this chapter is to provide an update of recent published literature and highlight progress in the field.

MAIN FINDINGS

Low carbohydrate intake, soy protein, ω3 fat, green teas, tomatoes and tomato products and the herbal mixture-zyflamend showed promise in reducing PCa risk or progression. On the contrary, a higher animal fat intake and a higher β-carotene status may increase risk. A "U" shape relationship may exist between folate, vitamin C, vitamin D and calcium with PCa risk. Conclusion Despite the inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa remains promising. Maintaining a healthy body weight and following a healthy dietary pattern including antioxidant rich fruits and vegetables, reduced animal fat and refined carbohydrates, should be encouraged.

CONCLUSION

Despite the inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa remains promising. Maintaining a healthy body weight and following a healthy dietary pattern including antioxidant rich fruits and vegetables, reduced animal fat and refined carbohydrates, should be encouraged.