Pharmacological manipulation of TRPC5 by kaempferol attenuates metastasis of gastrointestinal cancer via inhibiting calcium involved in the formation of filopodia.

The thermo-sensory receptor, transient receptor potential channel 5 (TRPC5), a non-selective calcium ion (Ca2+)-permeable ion channel, has been implicated in cancer initiation and progression. However, its specific role in gastrointestinal cancer remains unclear. This study demonstrates that TRPC5 is significantly overexpressed in gastrointestinal tumors and is inversely associated with patient prognosis. TRPC5 overexpression triggers a substantial elevation in intracellular Ca2+ levels ([Ca2+]i), driving actin cytoskeleton reorganization and facilitating filopodia formation. Furthermore, kaempferol, a compound sourced from traditional Chinese medicine, is identified as a TRPC5 inhibitor that effectively suppresses its activity, thereby impeding gastrointestinal cancer metastasis. These findings underscore the potential of TRPC5 as a therapeutic target for metastasis inhibition, with kaempferol emerging as a promising natural inhibitor that could be optimized for clinical use in preventing cancer metastasis.

Baicalin reduces chronic stress-induced breast cancer metastasis via directly targeting ß2-adrenergic receptor.

Recent studies have shown that stress can substantially facilitate breast cancer metastasis, which can be reduced by nonselective ß1/ß2-adrenergic receptor (ß1/ß2-AR) blocker. However, several side effects were identified. Thus, it is extremely warranted to explore more effective and better-tolerated ß2-AR blocker. Currently, we demonstrated that baicalin (BA), a major bioactive component of Scutellaria baicalensis Georgi, could significantly attenuate stress hormones especially epinephrine (Epi)-induced breast cancer cell migration and invasion in vitro. Mechanistically, we identified that ß2-AR was a direct target of BA via the drug affinity responsive target stability (DARTS) combined with mass spectrum assay, and BA photoaffinity probe with pull-down assay, which was further confirmed by a couple of biophysical and biochemical assays. Furthermore, we demonstrated that BA could directly bind to the Phe-193 and Phe-289 of ß2-AR, subsequently inhibit cyclic adenosine monophosphate-protein kinase A-focal adhesion kinase (cAMP-PKA-FAK) pathway, and thus impede epithelial-mesenchymal transition (EMT), thereby hindering the metastatic progression of the chronic stress coupled with syngeneic and xenograft in vivo orthotopic and tail vein mouse model. These findings firstly identify BA as a potential ß2-AR inhibitor in the treatment of stress-induced breast cancer metastasis.

Targeting PKM2 signaling cascade with salvianic acid A normalizes tumor blood vessels to facilitate chemotherapeutic drug delivery.

Aberrant tumor blood vessels are prone to propel the malignant progression of tumors, and targeting abnormal metabolism of tumor endothelial cells emerges as a promising option to achieve vascular normalization and antagonize tumor progression. Herein, we demonstrated that salvianic acid A (SAA) played a pivotal role in contributing to vascular normalization in the tumor-bearing mice, thereby improving delivery and effectiveness of the chemotherapeutic agent. SAA was capable of inhibiting glycolysis and strengthening endothelial junctions in the human umbilical vein endothelial cells (HUVECs) exposed to hypoxia. Mechanistically, SAA was inclined to directly bind to the glycolytic enzyme PKM2, leading to a dramatic decrease in endothelial glycolysis. More importantly, SAA improved the endothelial integrity via activating the ß-Catenin/Claudin-5 signaling axis in a PKM2-dependent manner. Our findings suggest that SAA may serve as a potent agent for inducing tumor vascular normalization.

Systematic optimization and evaluation of culture conditions for the construction of circulating tumor cell clusters using breast cancer cell lines.

BACKGROUND: Circulating tumor cell (CTC) clusters play a critical role in carcinoma metastasis. However, the rarity of CTC clusters and the limitations of capture techniques have retarded the research progress. In vitro CTC clusters model can help to further understand the biological properties of CTC clusters and their clinical significance. Therefore, it is necessary to establish reliable in vitro methodological models to form CTC clusters whose biological characteristics are very similar to clinical CTC clusters. METHODS: The assays of immunofluorescence, transmission electron microscopy, EdU incorporation, cell adhension and microfluidic chips were used. The experimental metastasis model in mice was used. RESULTS: We systematically optimized the culture methods to form in vitro CTC clusters model, and more importantly, evaluated it with reference to the biological capabilities of reported clinical CTC clusters. In vitro CTC clusters exhibited a high degree of similarity to the reported pathological characteristics of CTC clusters isolated from patients at different stages of tumor metastasis, including the appearance morphology, size, adhesive and tight junctions-associated proteins, and other indicators of CTC clusters. Furthermore, in vivo experiments also demonstrated that the CTC clusters had an enhanced ability to grow and metastasize compared to single CTC. CONCLUSIONS: The study provides a reliable model to help to obtain comparatively stable and qualified CTC clusters in vitro, propelling the studies on tumor metastasis.

Rosmarinic acid in combination with ginsenoside Rg1 suppresses colon cancer metastasis via co-inhition of COX-2 and PD1/PD-L1 signaling axis.

Metastasis of colorectal cancer (CRC) is a leading cause of mortality among CRC patients. Elevated COX-2 and PD-L1 expression in colon cancer tissue has been linked to distant metastasis of tumor cells. Although COX-2 inhibitors and immune checkpoint inhibitors demonstrate improved anti-tumor efficacy, their toxicity and variable therapeutic effects in individual patients raise concerns. To address this challenge, it is vital to identify traditional Chinese medicine components that modulate COX-2 and PD-1/PD-L1: rosmarinic acid (RA) exerts striking inhibitory effect on COX-2, while ginsenoside Rg1 (GR) possesses the potential to suppress the binding of PD-1/PD-L1. In this study we investigated whether the combination of RA and GR could exert anti-metastatic effects against CRC. MC38 tumor xenograft mouse model with lung metastasis was established. The mice were administered RA (100 mg·kg-1·d-1, i.g.) alone or in combination with GR (100 mg·kg-1·d-1, i.p.). We showed that RA (50, 100, 150 µM) or a COX-2 inhibitor Celecoxib (1, 3, 9 µM) concentration-dependently inhibited the migration and invasion of MC38 cells in vitro. We further demonstrated that RA and Celecoxib inhibited the metastasis of MC38 tumors in vitro and in vivo via interfering with the COX-2-MYO10 signaling axis and inhibiting the generation of filopodia. In the MC38 tumor xenograft mice, RA administration significantly decreased the number of metastatic foci in the lungs detected by Micro CT scanning; RA in combination with GR that had inhibitory effect on the binding of PD-1 and PD-L1 further suppressed the lung metastasis of colon cancer. Compared to COX-2 inhibitors and immune checkpoint inhibitors, RA and GR displayed better safety profiles without disrupting the tissue structures of the liver, stomach and colon, offering insights into the lower toxic effects of clinical traditional Chinese medicine against tumors while retaining its efficacy.

Unveiling the covert interaction between gut microbiota and neutrophils to drive colorectal cancer metastasis.

The formation of the microenvironment preceding liver metastasis is intricately linked to the intestinal tract. In recent years, mounting evidence has revealed the significant involvement of neutrophil extracellular traps (NETs) in tumor metastasis, particularly in liver metastasis. Disruption of the intestinal barrier can lead to the translocation of bacteria and their metabolites, such as lipopolysaccharide, into the liver. As the primary defense against pathogens, NETs help eliminate gut-derived toxins and shape the liver's inflammatory and immunosuppressive environment. However, this double-edged sword effect can potentially stimulate tumor metastasis by creating a fertile ground for the growth of intestinal tumor cells due to impaired liver tissue and reduced activity of killer immune cells. This comprehensive review systematically describes the influence factors and mechanisms of NETs in colon cancer metastasis and explores their potential as biomarkers and therapeutic targets for liver metastasis.

Ginsenoside Rh2 enhances immune surveillance of natural killer (NK) cells via inhibition of ERp5 in breast cancer.

BACKGROUND: One critical component of the immune system that prevents breast cancer cells from forming distant metastasis is natural killer (NK) cells participating in immune responses to tumors. Ginsenoside Rh2 (GRh2) as one of the major active ingredients of ginseng has been employed in treatment of cancers, but the function of GRh2 in modulating the development of breast cancer remains elusive. PURPOSE: This study was to dissect the effect of GRh2 against breast cancer and its potential mechanisms associated with NK cells, both in vitro and in vivo. METHODS: MDA-MB-231 and 4T1 cells were used to establish in situ and hematogenous mouse models. MDA-MB-231 and MCF-7 were respectively co-cultured with NK92MI cells or primary NK cells in vitro. Anti-tumor efficacy of GRh2 was verified by immunohistochemistry (IHC), Cell Counting Kit-8 (CCK8), high resolution micro-computed tomography (micro-CT) scanning of lungs and hematoxylin and eosin (H&E) staining. Lactate dehydrogenase (LDH) cytotoxicity assay, flow cytometry, in vivo depletion of NK cells, enzyme-linked immunosorbent assay (ELISA), western blot, quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunofluorescence and cell transfection were performed for investigating the anti-tumor mechanisms of GRh2. Molecular docking, microscale thermophoresis (MST) and cellular thermal shift assay (CETSA) were employed to determine the binding between endoplasmic reticulum protein 5 (ERp5) and GRh2. RESULTS: We demonstrated that GRh2 exerted prominent impacts on retarding the growth and metastasis of breast cancer through boosting the cytotoxic function of NK cells, as validated by the elevated release of perforin, granzyme B and interferon-γ (IFN-γ). Mechanistical studies revealed that GRh2 was capable of diminishing the expression of ERp5 and GRh2 directly bound to ERp5 in MDA-MB-231 cells as well as on a recombinant protein level. GRh2 prevented the formation of soluble MICA (sMICA) and upregulated the expression level of MICA in vivo and in vitro. Importantly, the reduced lung metastasis of breast cancer by GRh2 was almost abolished upon the depletion of NK cells. Moreover, GRh2 was able to insert into the binding pocket of ERp5 directly. CONCLUSION: We firstly demonstrated that GRh2 played a pivotal role in augmenting NK cell activity by virtue of modulating the NKG2D-MICA signaling axis via directly binding to ERp5, and may be further optimized to a therapeutic agent for the treatment of breast cancer.

Optimization of cancer immunotherapy on the basis of programmed death ligand-1 distribution and function.

Programmed cell death protein-1 (PD-1)/programmed death ligand-1 (PD-L1) immune checkpoint blockade as a breakthrough in cancer immunotherapy has shown unprecedented positive outcomes in the clinic. However, the overall effectiveness of PD-L1 antibody is less than expected. An increasing number of studies have demonstrated that PD-L1 is widely distributed and expressed not only on the cell membrane but also on the inside of the cells as well as on the extracellular vesicles secreted by tumour cells. Both endogenous and exogenous PD-L1 play significant roles in influencing the therapeutic effect of anti-tumour immunity. Herein, we mainly focused on the distribution and function of PD-L1 and further summarized the potential targeted therapeutic strategies. More importantly, in addition to taking the overall expression abundance of PD-L1 as a predictive indicator for selecting corresponding PD-1/PD-L1 monoclonal antibodies (mAbs), we also proposed that personalized combination therapies based on the different distribution of PD-L1 are worth attention to achieve more efficient and effective therapeutic outcomes in cancer patients. LINKED ARTICLES: This article is part of a themed issue on Cancer Microenvironment and Pharmacological Interventions. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.2/issuetoc.

Capsaicin orchestrates metastasis in gastric cancer via modulating expression of TRPV1 channels and driving gut microbiota disorder.

The association between capsaicin, the major natural pungent compound of chili peppers, and gastric cancer progression has engendered conflicting findings. In this work, we sought to explore the character of a high capsaicin diet in gastric cancer metastasis and its possible mechanism. The impact of high capsaicin consumption on gastric cancer metastasis was investigated in vivo (xenograft mouse and zebrafish models) and in vitro (biochemical and molecular assays). It was demonstrated that high diet of capsaicin gave rise to accelerate tumor metastasis, which was partially mediated by elevating the expression of transient receptor potential vanilloid 1 (TRPV1) in gastric cancer cells. Importantly, we found that genetic depletion of TRPV1 could reduce gastric cancer metastasis by diminishing the motility of tumor cells in vitro, but acted poorly in xenograft mouse model. Considering the distribution of capsaicin in vivo, 16S rRNA sequencing and fecal microbiota transplantation (FMT) were used to appraise whether the gut microbiota involved in the high capsaicin diet induced metastasis. It was demonstrated that the level of Firmicutes and Clostridiales was expressively boosted following the high consumption of capsaicin. This microbial shift contributed to the increased peripheral 5-hydroxytryptamine (5-HT) levels, yielding the aggravated metastatic burden. Collectively, our findings highlighted the potential risk of high capsaicin diet in promoting gastric cancer metastasis by virtue of modulating TRPV1 expression and gut microbiota composition, indicating the importance of controlled consumption of chili peppers for patients with gastric cancer. Video Abstract.

Salvia mitiorrhiza Bunge aqueous extract attenuates infiltration of tumor-associated macrophages and potentiates anti-PD-L1 immunotherapy in colorectal cancer through modulating Cox2/PGE2 cascade.

ETHNOPHARMACOLOGICAL RELEVANCE: Based on the notion of traditional Chinese medicine, the theory of invigorating the circulation of blood is a prominent treatment for cancer in clinic. Therefore, Salvia miltiorrhiza Bunge, as a representative of Chinese medicine of invigorating the circulation of blood, has been proved to be an effective medicinal herb for treating cancer. AIM OF THE STUDY: To clarify the anti-cancer effect of Salvia miltiorrhiza Bunge aqueous extract (SMAE) on colorectal cancer (CRC) and investigate whether the therapeutic effect of SMAE was mediated by attenuating the infiltration of tumor-associated macrophages (TAMs) into the tumor microenvironment (TME). MATERIALS AND METHODS: High-performance liquid chromatography (HPLC) was used for determined the main compounds of SMAE. MC38 cells were subcutaneously injected into the mice to establish the mouse model of CRC. Tumor growth curve was detected by tumor volume measurement. The model group received distilled water irrigation once a day. SMAE-treated group received 5 g/kg or 10 g/kg SMAE once a day. Anti-PD-L1 treated group received 5 mg/kg anti-PD-L1 once every three days. Protein expression of Cox2 and PD-L1 was determined by Western blot assay. The secretion levels of PGE2, IL-1ß, IL-6, MCP-1, and GM-CSF were evaluated through ELISA. The mRNA expression of CSF1, CCL2, CXCL1, CXCL2, and CXCL3 was measured by using RT-qPCR. Staining of Ki67, TUNEL and Caspase3 was used to investigate cell proliferation and apoptosis. Immunohistochemical staining was used to determine CD8+ T cell distribution. H&E staining was used to confirm histopathological changes. The expressions of F4/80 and CD68 were measured by flow cytometry to identify macrophages in tumors and lymph nodes. The number of CD8+ T cells and the expression of PD-1, IFN-γ, and Granzyme B (GZMB) were determined by flow cytometry. RESULTS: SMAE significantly retarded the growth of MC38 mouse colorectal cancer. SMAE strikingly inhibited the expression of Cox2 and impaired the secretion of PGE2 in tumors, contributing to the attenuated intra-tumoral infiltration of TAMs via Cox2/PGE2 cascade. Meanwhile, SMAE augmented anti-tumor immunity by the elevated proportion of IFN-γ+ CD8+ T cells and GZMB+ CD8+ T cells, which decreased the tumor load. Furthermore, the combination of SMAE and anti-PD-L1 showed a higher therapeutic efficacy than either monotherapy in controlling tumor growth in MC38 xenograft model. CONCLUSIONS: SMAE attenuated the infiltration of TAMs into tumors and synergized with anti-PD-L1 to treat CRC via modulating Cox2/PGE2 cascade.

Capsaicin shapes gut microbiota and pre-metastatic niche to facilitate cancer metastasis to liver.

Dietary factors are fundamental in tumorigenesis throughout our lifetime. A spicy diet has been ambiguous on the development of cancers, especially in the study of colon cancer metastasis. Here, we utilized a mouse metastasis model to test the potential role of capsaicin in influencing metastasis. Long-term continuous administration of capsaicin diet (300 mg/kg) to mice promotes the formation of liver pre-metastatic niche to facilitate the metastasis of colon cancer cells. Bacteria translocation to liver is clearly observed. Capsaicin increases intestinal barrier permeability and disrupts gut vascular barrier by altering the composition of gut microbiota. Capsaicin not only changes the abundance of mucin-related bacteria like Akkermanisa and Muribaculaceae, but also bacteria involved in bile acids metabolism. Dysregulated bile acids profile is related to the recruitment of natural killer T (NKT) cells in pre-metastatic niche, primary bile acid α-Muricholic acid can enhance the recruitment of NKT cells, while secondary bile acids Glycoursodeoxycholic acid and Taurohyodeoxycholic acid impair the recruitment of NKT cells. These findings reveal long term consumption of capsaicin increases the risk of cancer metastasis through modulating the gut microbiota. Capsaicin (300 mg/kg) disrupts gut barrier and promotes the translocation of bacteria to liver, while altered bile acids metabolism affects the recruitment of NKT cells in liver, forming a pre-metastatic niche and promoting cancer metastasis.

Ginseng polysaccharides: Potential antitumor agents.

As a famous herbal medicine in China and Asia, ginseng (Panax ginseng C. A. Meyer) is also known as the "King of All Herbs" and has long been used in medicine and healthcare. In addition to the obvious biological activities of ginsenosides, ginseng polysaccharides (GPs) exhibit excellent antitumor, antioxidant stress, and immunomodulatory effects. In particular, GPs can exert an antitumor effect and is a potential immunomodulator. However, due to the complexity and diversity in the structures and components of GPs, their specific physicochemical properties, and underlying mechanisms remain unclear. In this article, we have summarized the factors influencing the antitumor activity of GPs and their mechanism of action, including the stimulation of the immune system, regulation of the gut microbiota, and direct action on tumor cells.

Thermo-Transient Receptor Potential Channels: Therapeutic Potential in Gastric Cancer.

Over the last decade, researchers have found abnormal expression of transient receptor potential (TRP) channels. In particular, members of the thermally sensitive subclass (thermo-TRPs) are involved in many disease processes. Moreover, they have a vital role in the occurrence and development of gastric cancer (GC). Accordingly, thermo-TRPs constitute a major pharmacological target, and the elucidation of the mechanisms underlying their response to physiological stimuli or drugs is key for notable advances in GC treatment. Therefore, this paper summarizes the existing literature about thermo-TRP protein expression changes that are linked to the incidence and progression of GC. The review also discusses the implication of such association to pathology and cell physiology and identifies potential thermo-TRP protein targets for diagnosis and treatment of GC.

TRPV4 Promotes Metastasis in Melanoma by Regulating Cell Motility through Cytoskeletal Rearrangement.

The abnormal expression of Transient Receptor Potential cation channel subfamily V member 4 (TRPV4) is closely related to the progression of multiple tumors. In addition, TRPV4 is increasingly being considered a potential target for cancer therapy, especially in tumor metastasis prevention. However, the biological correlation between TRPV4 and tumor metastasis, as well as the specific role of TRPV4 in malignant melanoma metastasis, is poorly understood. In this study, we aimed to examine the role of TRPV4 in melanoma metastasis through experiments and clinical data analysis, and the underlying anticancer mechanism of Baicalin, a natural compound, and its inhibitory effect on TRPV4 with in vivo and in vitro experiments. Our findings suggested that TRPV4 promotes metastasis in melanoma by regulating cell motility via rearranging the cytoskeletal, and Baicalin can inhibit cancer metastasis, whose mechanisms reverse the recruitment of activated cofilin to leading-edge protrusion and the increasing phosphorylation level of cortactin, which is provoked by TRPV4 activation.

Manipulation of the crosstalk between tumor angiogenesis and immunosuppression in the tumor microenvironment: Insight into the combination therapy of anti-angiogenesis and immune checkpoint blockade.

Immunotherapy has been recognized as an effective and important therapeutic modality for multiple types of cancer. Nevertheless, it has been increasing recognized that clinical benefits of immunotherapy are less than expected as evidenced by the fact that only a small population of cancer patients respond favorably to immunotherapy. The structurally and functionally abnormal tumor vasculature is a hallmark of most solid tumors and contributes to an immunosuppressive microenvironment, which poses a major challenge to immunotherapy. In turn, multiple immune cell subsets have profound consequences on promoting neovascularization. Vascular normalization, a promising anti-angiogenic strategy, can enhance vascular perfusion and promote the infiltration of immune effector cells into tumors via correcting aberrant tumor blood vessels, resulting in the potentiation of immunotherapy. More interestingly, immunotherapies are prone to boost the efficacy of various anti-angiogenic therapies and/or promote the morphological and functional alterations in tumor vasculature. Therefore, immune reprograming and vascular normalization appear to be reciprocally regulated. In this review, we mainly summarize how tumor vasculature propels an immunosuppressive phenotype and how innate and adaptive immune cells modulate angiogenesis during tumor progression. We further highlight recent advances of anti-angiogenic immunotherapies in preclinical and clinical settings to solidify the concept that targeting both tumor blood vessels and immune suppressive cells provides an efficacious approach for the treatment of cancer.

Systemic pharmacological verification of Salvia miltiorrhiza-Ginseng Chinese herb pair in inhibiting spontaneous breast cancer metastasis.

Breast cancer is the most commonly diagnosed cancer in the world, and metastasis is often the main cause of death in breast cancer patients. Salvia miltiorrhiza -Ginseng (SG) herb pair is clinically used for the treatment of cardiovascular diseases and cancers. However, the pharmacological action of this pair on breast cancer is yet unclear. In this study, a spontaneous metastasis model of breast cancer was constructed to assess the therapeutic value of SG. After administration of different doses of SG, the results showed that although it did not significantly inhibit tumor growth, high-dose SG administration could inhibit tumor metastasis. Then, based on systematic pharmacology combined with Gene Expression Omnibus (GEO) database, potential targets of drugs were identified such as vascular endothelial growth factor A (VEGFA), matrix metalloproteinase (MMP9), prostaglandin endoperoxide synthase2 (PTGS2), etc. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) analysis revealed that these targets were related to cytokine-mediated signaling pathway, cell migration and other biological processes and signaling pathways such as PI3K/Akt, etc. The systematic pharmacology analysis showed that SG effectively inhibited the VEGFA and MMP9-mediated biological events such as angiogenesis, epithelial-mesenchymal transition (EMT) and impaired tumor metastasis. Overall, our research aimed to provide new ideas for the treatment of breast cancer lung metastasis in traditional Chinese medicine.

Kaempferol impairs aerobic glycolysis against melanoma metastasis via inhibiting the mitochondrial binding of HK2 and VDAC1.

Metastasis is the leading cause of death in melanoma patients. Aerobic glycolysis is a common metabolic feature in tumor and is closely related to cell growth and metastasis. Kaempferol (KAM) is one of the active ingredients in the total flavonoids of Chinese traditional medicine Sparganii Rhizoma. Studies have shown that it interferes with the cell cycle, apoptosis, angiogenesis and metastasis of tumor cells, but whether it can affect the aerobic glycolysis of melanoma is still unclear. Here, we explored the effects and mechanisms of KAM on melanoma metastasis and aerobic glycolysis. KAM inhibited the migration and invasion of A375 and B16F10 cells, and reduced the lung metastasis of melanoma cells. Extracellular acidification rates (ECAR) and glucose consumption were obviously suppressed by KAM, as well as the production of ATP, pyruvate and lactate. Mechanistically, the activity of hexokinase (HK), the first key kinase of aerobic glycolysis, was significantly inhibited by KAM. Although the total protein expression of HK2 was not significantly changed, the binding of HK2 and voltage-dependent anion channel 1 (VDAC1) on mitochondria was inhibited by KAM through AKT/GSK-3ß signal pathway. In conclusion, KAM inhibits melanoma metastasis via blocking aerobic glycolysis of melanoma cells, in which the binding of HK2 and VDAC1 on mitochondria was broken.

Inducing vascular normalization: A promising strategy for immunotherapy.

In solid tumors, the vasculature is highly abnormal in structure and function, resulting in the formation of an immunosuppressive tumor microenvironment by limiting immune cells infiltration into tumors. Vascular normalization is receiving much attention as an alternative strategy to anti-angiogenic therapy, and its potential therapeutic targets include signaling pathways, angiogenesis-related genes, and metabolic pathways. Endothelial cells play an important role in the formation of blood vessel structure and function, and their metabolic processes drive blood vessel sprouting in parallel with the control of genetic signals in cancer. The feedback loop between vascular normalization and immunotherapy has been discussed extensively in many reviews. In this review, we summarize the impact of aberrant tumor vascular structure and function on drug delivery, metastasis, and anti-tumor immune responses. In addition, we present evidences for the mutual regulation of immune vasculature. Based on the importance of endothelial metabolism in controlling angiogenesis, we elucidate the crosstalk between endothelial cells and immune cells from the perspective of metabolic pathways and propose that targeting abnormal endothelial metabolism to achieve vascular normalization can be an alternative strategy for cancer treatment, which provides a new theoretical basis for future research on the combination of vascular normalization and immunotherapy.

Pharmacological manipulation of Ezh2 with salvianolic acid B results in tumor vascular normalization and synergizes with cisplatin and T cell-mediated immunotherapy.

Tumor vasculature is characterized by aberrant structure and function, resulting in immune suppressive profiles of tumor microenvironment (TME) through limiting immune cell infiltration into tumors. The defective vascular perfusion in tumors also impairs the delivery and efficacy of chemotherapeutic agents. Targeting abnormal tumor blood vessels has emerged as an effective therapeutic strategy to improve the outcome of chemotherapy and immunotherapy. In this study, we demonstrated that Salvianolic acid B (SalB), one of the major ingredients of Salvia miltiorriza elicited vascular normalization in the mouse models of breast cancer, contributing to improved delivery and response of chemotherapeutic agent cisplatin as well as attenuated metastasis. Moreover, SalB in combination with anti-PD-L1 blockade retarded tumor growth, which was mainly due to elevated infiltration of immune effector cells and boosted delivery of anti-PD-L1 into tumors. Mechanistically, tumor cell enhancer of zeste homolog 2 (Ezh2)-driven cytokines disrupted the endothelial junctions with diminished VE-cadherin expression, which could be rescued in the presence of SalB. The restored vascular integrity by SalB via modulating the interactions between tumor cells and endothelial cells (ECs) offered a principal route for achieving vascular normalization. Taken together, our data elucidated that SalB enhanced sensitivity of tumor cells to chemotherapy and immunotherapy through triggering tumor vascular normalization, providing a potential therapeutic strategy of combining SalB and chemotherapy or immunotherapy for patients with breast cancer.

Novel GSK-3 kinase inhibitor Pym-5 induces GSK-3ß rather than GSK-3α-dependent melanogenesis in murine melanoma cells.

BACKGROUND: Glycogen synthase kinase-3 (GSK-3) inhibitors are considered to activate Wnt/ß-Catenin, which remains a controversial topic in melanoma treatment. OBJECTIVE: Here, we have developed Pym-5, an attractive GSK-3 inhibitor. Using Pym-5 as a chemical tool to probe the GSK-3 biology, we aimed to investigate the potential of GSK-3 inhibition as a strategy of melanoma treatment and underlying mechanisms. METHODS: Using pigment B16 and B16BL6 murine melanoma model in vitro and a zebrafish pigmentation model in vivo, we investigated Pym-5-meditaed activation of Wnt/ß-Catenin, melanogenesis and antitumor response in melanoma treatment. RESULTS: We found that Pym-5 delayed the growth and promoted melanogenesis of melanoma cells. Pym-5 activated the transcription of ß-Catenin and responsive targets genes (AXIN2 and MITF), melanin biosynthesis genes (TYR, TYRP1 and TYRP2) and eventually elevated the production of melanin. Interestingly, genetic inactivation of GSK-3ß, but not its paralogue GSK-3α, compromised Pym-5-mediated melanogenesis in B16 and B16BL6 cells. CONCLUSION: These data provide insight into the potential therapeutic benefits obtained from activation of Wnt/ß-Catenin signaling pathway and how Pym-5 can regulate melanin production and the rationale for future clinical application of GSK-3 inhibitor in melanoma patients.