FOXM1 mediates methotrexate resistance in osteosarcoma cells by promoting autophagy.

Osteosarcoma (OS) is a primary bone cancer mostly found in adolescents and elderly individuals. The treatment of OS is still largely dependent on traditional chemotherapy. However, the high incidence of drug resistance remains one of the greatest impediments to limiting improvements in OS treatment. Recent findings have indicated that the transcription factor FOXM1 plays an important role in various cancer-related events, especially drug resistance. However, the possible role of FOXM1 in the resistance of OS to methotrexate (MTX) remains to be explored. Here, we find that FOXM1, which confers resistance to MTX, is highly expressed in OS tissues and MTX-resistant cells. FOXM1 overexpression promotes MTX resistance by enhancing autophagy in an HMMR/ATG7-dependent manner. Importantly, silencing of FOXM1 or inhibiting autophagy reverses drug resistance. These findings demonstrate a new mechanism for FOXM1-induced MTX resistance and provide a promising target for improving OS chemotherapy outcomes.

The protective effect of erythropoietin and its novel derived peptides in peripheral nerve injury.

Peripheral nerve injury seriously endangers human life and health, but there is no clinical drug for the treatment of peripheral nerve injury, so it is imperative to develop drugs to promote the repair of peripheral nerve injury. Erythropoietin (EPO) not only has the traditional role of promoting erythropoiesis, but also has a tissue-protective effect. Over the past few decades, researchers have confirmed that EPO has neuroprotective effects. However, side effects caused by long-term use of EPO limited its clinical application. Therefore, EPO derivatives with low side effects have been explored. Among them, ARA290 has shown significant protective effects on the nervous system, but the biggest disadvantage of ARA290, its short half-life, limits its application. To address the short half-life issue, the researchers modified ARA290 with thioether cyclization to generate a thioether cyclized helical B peptide (CHBP). ARA290 and CHBP have promising applications as peptide drugs. The neuroprotective effects they exhibit have attracted continuous exploration of their mechanisms of action. This article will review the research on the role of EPO, ARA290 and CHBP in the nervous system around this developmental process, and provide a certain reference for the subsequent research.

Inhibition of inosine metabolism of the gut microbiota decreases testosterone secretion in the testis.

Growing evidence indicates that gut microbiota is involved in the regulation of the host's sex hormone levels, such as through interfering with the sex hormone metabolism in the intestine. However, if gut microbiota or its metabolites directly influence the sex hormone biosynthesis in the gonad remains largely unknown. Our previous study showed that colistin, as a narrow-spectrum antibiotic, can significantly downregulate the serum testosterone levels and thus enhance the antitumor efficiency of anti-PD-L1 in male mice; however, the underlying mechanism for the regulation of the host's testosterone levels remains uninvestigated. In the present study, we analyzed the impact of colistin on the immune microenvironment of the testis as well as the composition and metabolism of gut microbiota in male mice. Our results showed that colistin has an impact on the immune microenvironment of the testis and can downregulate serum testosterone levels in male mice through inhibition of Akkermansia, leading to destroyed inosine metabolism. Supplement with inosine can restore testosterone secretion probably by prompting the recovery of the intestinal mucus barrier and the serum lipopolysaccharides levels. All these findings reveal a new pathway for the regulation of the host's sex hormone levels by gut microbiota.IMPORTANCEThis study demonstrates that exposure to even narrow-spectrum antibiotics may affect the host's testosterone levels by altering the gut microbiota and its metabolites. Our findings provide evidence that some specific gut bacteria have an impact on the sex hormone biosynthesis in the testis.

CXCL1-CXCR2 axis mediates inflammatory response after sciatic nerve injury by regulating macrophage infiltration.

Macrophages play a crucial role in the inflammatory response following sciatic nerve injury. Studies have demonstrated that C-X-C motif chemokine (CXCL) 1 recruit macrophages by binding to C-X-C chemokine receptor (CXCR) 2 and participates in the inflammatory response of various diseases. Based on these findings, we aimed to explore the role of the CXCL1-CXCR2 axis in the repair process after peripheral nerve injury. Initially, we simulated sciatic nerve injury and observed an increased expression of CXCL1 and CXCR2 in the nerves of the injury group. Both in vivo and in vitro experiments confirmed that the heightened CXCL1 expression occurs in Schwann cells and is secreted, while the elevated CXCR2 is expressed by recruited macrophages. In addition, in vitro experiments demonstrated that the binding of CXCL1 to CXCR2 can activate the NLRP3 inflammasome and promote the production of interleukin-1 beta (IL-1ß) in macrophages. However, after mice were subjected to sciatic nerve injury, the number of macrophages and the expression of inflammatory factors in the sciatic nerve were reduced following treatment with the CXCR2 inhibitor SB225002. Simultaneously, we evaluated the sciatic nerve function index, the expression of p75 neurotrophic factor receptor (p75NTR), and myelin proteins, and all of these results were improved with the use of SB225002. Thus, our results suggest that after sciatic nerve injury, the CXCL1-CXCR2 axis mediates the inflammatory response by promoting the recruitment and activation of macrophages, which is detrimental to the repair of the injured nerves. In contrast, treatment with SB225002 promotes the repair of injured sciatic nerves.

Pathogenic Th17 cell-mediated liver fibrosis contributes to resistance to PD-L1 antibody immunotherapy in hepatocellular carcinoma.

Understanding the mechanisms of resistance of hepatocellular carcinoma (HCC) to targeted therapies and immune checkpoint blockade is critical for the development of new combination therapies and improving patient survival. Here, we found that in HCC, anti-programmed cell death 1 ligand 1 (PD-L1) therapy reduces liver cancer growth, but the tumors eventually become resistant to continued therapy. Experimental analyses shows that the infiltration of pathogenic T helper 17 (pTh17) cells increases in drug-resistant HCC, and pTh17 cells secrete interleukin-17A (IL-17A), which promotes the expression of PD-L1 on the surface of HCC cells and produces resistance to anti-PD-L1 therapy. Anti-IL-17A combined with PD-L1 blockade significantly increased the infiltration of cytotoxic CD8+ T cells expressing high levels of interferon-γ and reduced treatment resistance in HCC. These results support the combination of anti-PD-L1 and anti-IL-17A as a novel strategy to induce effective T cell-mediated anti-tumor immune responses.

IL-17A functions and the therapeutic use of IL-17A and IL-17RA targeted antibodies for cancer treatment.

Interleukin 17A (IL-17A) is a major member of the IL-17 cytokine family and is produced mainly by T helper 17 (Th17) cells. Other cells such as CD8+ T cells, γδ T cells, natural killer T cells and innate lymphoid-like cells can also produce IL-17A. In healthy individuals, IL-17A has a host-protective capacity, but excessive elevation of IL-17A is associated with the development of autoimmune diseases and cancer. Monoclonal antibodies (mAbs) targeting IL-17A (e.g., ixekizumab and secukinumab) or IL-17A receptor (IL-17RA) (e.g., brodalumab) would be investigated as potential treatments for these diseases. Currently, the application of IL-17A-targeted drugs in autoimmune diseases will provide new ideas for the treatment of tumors, and its combined application with immune checkpoint inhibitors has become a research hotspot. This article reviews the mechanism of action of IL-17A and the application of anti-IL-17A antibodies, focusing on the research progress on the mechanism of action and therapeutic blockade of IL-17A in various tumors such as colorectal cancer (CRC), lung cancer, gastric cancer and breast cancer. Moreover, we also include the results of therapeutic blockade in the field of cancer as well as recent advances in the regulation of IL-17A signaling.

Enhancing therapeutic effects of murine cancer vaccine by reshaping gut microbiota with Lactobacillus rhamnosus GG and jujube powder.

Cancer vaccines have gained widespread attention in recent years as an emerging treatment for tumors. However, most therapeutic cancer vaccines have failed in phase III clinical trials due to faint clinical benefits. In this study, we funded that a specific synbiotic composing Lactobacillus rhamnosus GG (LGG) and jujube powder significantly enhanced the therapeutic effects of whole cells cancer vaccine in MC38 cancer cells bearing-mouse. The utilization of LGG increased the abundance of Muribaculaceae, which is conductive to an enhanced anti-tumor effect, but reduced microbial α-diversity. The use of jujube nursed probiotic microorganisms in Lachnospiaceae and enriched microbial diversity, as indicated by increased Shannon and Chao index. The reshaped gut microbiota by this synbiotic improved lipid metabolism conductive to intensified infiltration of CD8+ T cells in the tumor microenvironment and enhanced the potency of above-mentioned cancer vaccine. These encouraging findings are helpful for further efforts towards enhancing the therapeutic effects of cancer vaccines through nutritional intervention.

The CXCL12-CXCR4-NLRP3 axis promotes Schwann cell pyroptosis and sciatic nerve demyelination in rats.

Studies have shown that the activation of the NOD-like receptor protein 3 (NLRP3) inflammasome is detrimental to the functional recovery of the sciatic nerve, but the regulatory mechanisms of the NLRP3 inflammasome in peripheral nerves are unclear. C-X-C motif chemokine 12 (CXCL12) can bind to C-X-C chemokine receptor type 4 (CXCR4) and participate in a wide range of nerve inflammation by regulating the NLRP3 inflammasome. Based on these, we explore whether CXCL12-CXCR4 axis regulates the NLRP3 inflammasome in the peripheral nerve. We found that CXCR4/CXCL12, NLRP3 inflammasome-related components, pyroptosis-related proteins and inflammatory factors in the sciatic nerve injured rats were markedly increased compared with the sham-operated group. AMD3100, a CXCR4 antagonist, reverses the activation of NLRP3 inflammasome, Schwann cell pyroptosis and sciatic nerve demyelination. We further treated rat Schwann cells with LPS (lipopolysaccharide) and adenosine triphosphate (ATP) to mimic the cellular inflammation model of sciatic nerve injury, and the results were consistent with those in vivo. In addition, both in vivo and in vitro experiments demonstrated that AMD3100 treatment reduced the phosphorylation of nuclear factor κB (NF-κB) and the expression of thioredoxin interacting protein (TXNIP), which contributes to activating NLRP3 inflammasome. Therefore, our findings suggest that, after sciatic nerve injury, CXCL12-CXCR4 axis may promote Schwann cell pyroptosis and sciatic nerve demyelination through activating NLRP3 inflammasome and slow the recovery process of the sciatic nerve.

The role of CXCL1/CXCR2 axis in neurological diseases.

The C-X-C chemokine ligand (CXCL) 1 and its receptor C-X-C chemokine receptor (CXCR) 2 are widely expressed in the peripheral nervous systems (PNS) and central nervous systems (CNS) and are involved in the development of inflammation and pain after various nerve injuries. Once a nerve is damaged, it affects not only the neuron itself but also lesions elsewhere in its dominant site. After the CXCL1/CXCR2 axis is activated, multiple downstream pathways can be activated, such as c-Raf/MAPK/AP-1, p-PKC-µ/p-ILK/NLRP3, JAK2/STAT3, TAK1/NF-κB, etc. These pathways in turn mediate cellular motility state or cell migration. CXCR2 is expressed on the surface of neutrophils and monocytes/macrophages. These cells can be recruited to the lesion through the CXCL1/CXCR2 axis to participate in the inflammatory response. The expression of CXCR2 in neurons can activate some pathways in neurons through the CXCL1/CXCR2 axis, thereby causing damage to neurons. CXCR2 is also expressed in astrocytes, and when CXCR2 activated, it increases the number of astrocytes but impairs their function. Since inflammation can occur at almost any site of injury, elucidating the mechanism of CXCL1/CXCR2 axis' influence on inflammation may provide a favorable target for clinical treatment. Therefore, this article reviews the research progress of the CXCL1/CXCR2 axis in neurological diseases, aiming to provide a more meaningful theoretical basis for the treatment of neurological diseases.

PKC-ζ mediated reduction of the extracellular vesicles-associated TGF-ß1 overcomes radiotherapy resistance in breast cancer.

BACKGROUND: Radiotherapy is widely applied in breast cancer treatment, while radiotherapy resistance is inevitable. TGF-ß1 has been considered to be an endogenous factor for the development of radiotherapy resistance. As a large portion of TGF-ß1 is secreted in an extracellular vesicles-associated form (TGF-ß1EV), particularly in radiated tumors. Thus, the understanding of the regulation mechanisms and the immunosuppressive functions of TGF-ß1EV will pave a way for overcoming the radiotherapy resistance in cancer treatment. METHODS: The superoxide-Zinc-PKC-ζ-TGF-ß1EV pathway in breast cancer cells was identified through sequence alignments of different PKC isoforms, speculation and experimental confirmation. A series of functional and molecular studies were performed by quantitative real-time PCR, western blot and flow cytometry analysis. Mice survival and tumor growth were recorded. Student's t test or two-way ANOVA with correction was used for comparisons of groups. RESULTS: The radiotherapy resulted in an increased expression of the intratumoral TGF-ß1 and an enhanced infiltration of the Tregs in the breast cancer tissues. The intratumoral TGF-ß1 was found mainly in the extracellular vesicles associated form both in the murine breast cancer model and in the human lung cancer tissues. Furthermore, radiation induced more TGF-ß1EV secretion and higher percentage of Tregs by promoting the expression and phosphorylation of protein kinase C zeta (PKC-ζ). Importantly, we found that naringenin rather than 1D11 significantly improved radiotherapy efficacy with less side effects. Distinct from TGF-ß1 neutralizing antibody 1D11, the mechanism of naringenin was to downregulate the radiation-activated superoxide-Zinc-PKC-ζ-TGF-ß1EV pathway. CONCLUSIONS: The superoxide-zinc-PKC-ζ-TGF-ß1EV release pathway was elucidated to induce the accumulation of Tregs, resulting in radiotherapy resistance in the TME. Therefore, targeting PKC-ζ to counteract TGF-ß1EV function could represent a novel strategy to overcome radiotherapy resistance in the treatment of breast cancer or other cancers. TRIAL REGISTRATION: The using of patient tissues with malignant Non-Small Cell Lung Cancer (NSCLC) was approved by the ethics committees at Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China (NCC2022C-702, from June 8th, 2022).

The role of the sex hormone-gut microbiome axis in tumor immunotherapy.

Accumulating evidence suggested that both gut microbiome and sex play a critical role in the efficacy of immune checkpoint blockade therapy. Considering the reciprocal relationship between sex hormones and gut microbiome, the sex hormone-gut microbiome axis may participate in the regulation of the response to immune checkpoint inhibitors (ICIs). In this review, it was attempted to summarize the current knowledge about the influences of both sex and gut microbiome on the antitumor efficacy of ICIs and describe the interaction between sex hormones and gut microbiome. Accordingly, this review discussed the potential of enhancing the antitumor efficacy of ICIs through regulating the levels of sex hormones through manipulation of gut microbiome. Collectively, this review provided reliable evidence concerning the role of the sex hormone-gut microbiome axis in tumor immunotherapy.

Sex-Biased Immune Responses to Antibiotics during Anti-PD-L1 Treatment in Mice with Colon Cancer.

Colitis is a frequently occurred side effect of immune checkpoint inhibitors (ICIs), which are increasingly used in cancer treatment, whereas antibiotics are widely used to treat colitis, their effectiveness in ICI-associated colitis remains controversial. In this study, we firstly assessed the effectiveness of several commonly used antibiotics and antibiotic cocktails in alleviating of dextran sulfate sodium- (DSS-) induced colitis. We observed that two narrow-spectrum antibiotics, neomycin and metronidazole, were more effective in alleviating colitis, as evidenced by the remission of loss of the body weight, enlargement of the spleen, shortening of the colon, secretion of proinflammatory cytokines, and histological score of the colon tissue. Moreover, these two antibiotics resulted in better relief of colitis symptoms in the MC38 tumor-bearing male mice receiving the anti-PD-L1 mAb (αPD-L1) treatment, compared to the females. In the meantime, an enhanced response to αPD-L1 efficiency against mice colon cancer was observed in the male mouse group upon the application of these two antibiotics. In contrast, both neomycin and metronidazole showed destructive effects on the antitumor efficiency of αPD-L1 in female mice, despite relief from colitis. We found that antibiotic treatment attenuated the increased infiltration of granulocytes and myeloid cells in colon tissue induced by DSS in female mice, while reducing the proportion of Th17 cells in male mice. These differences were further associated with the sex-biased differences in the gut microbiota. These findings indicated that sex-dependent alterations in the gut microbiota should be considered when applying antibiotics for the treatment of ICI-associated colitis.

Downregulating testosterone levels enhance immunotherapy efficiency.

Low response rates to certain tumor types remain a major challenge for immune checkpoint blockade therapy. In this study, we first conducted an integrated biomarker evaluation of bladder cancer patients from confirmatory cohorts (IMvigor210) and found that no significant differences exist between sexes before acceptance of anti-PD-L1 treatment, whereas male patients showed a better response. Thus, we then focused on sex-related changes post anti-PD-L1 treatment and found no obvious impact on the gut microbiota in male mice but a significant decrease in the sex hormone levels. Further, castration dramatically enhanced the antitumor efficacy against murine colon adenocarcinoma in male mice. Moreover, a narrow-spectrum antibiotic, colistin was innovatively used for deregulation of testosterone levels to enhance the immunotherapy efficiency in male mice. These findings indicate that the impact on the sex hormone levels in males may contribute to the sexual dimorphism in response and provide a promising way to enhance immunotherapy efficiency.

Ultrafine Jujube Powder Enhances the Infiltration of Immune Cells during Anti-PD-L1 Treatment against Murine Colon Adenocarcinoma.

Whereas dietary intervention with natural nutrients plays an important role in activating the immune response and holds unprecedented application potential, the underpinning mechanism is poorly understood. The present work was dedicated to comprehensively examine the effects of ultrafine jujube powder (JP) on the gut microbiota and, consequentially, the effects associated with the response rate to anti-PD-L1 treatment against murine colon adenocarcinoma. A murine colon adenocarcinoma model with anti-PD-L1 immunotherapy was established to evaluate how dietary interventions affect the microbiota. In vitro and in vivo experiments confirmed the role of SCFAs in the immune response. Oral administration of JP greatly improves the response of anti-PD-L1 treatment against murine colon adenocarcinoma. Such an improvement is associated with the alteration of gut microbiota which leads to an increased abundance of Clostridiales, including Ruminococcaceae and Lachnospiraceae, an elevated SCFA production, and an intensified infiltration of CD8+ T cells to the tumor microenvironment. This work demonstrates that JP is particularly effective in modulating the gut microbiota for an improved immune checkpoint blockage therapy by boosting cytotoxic CD8+ T cells in tumor-infiltrating lymphocytes. The experimental findings of the present study are helpful for the development of dietary intervention methods for cancer immunotherapy using natural nutrients.

Jujube Powder Enhances Cyclophosphamide Efficiency against Murine Colon Cancer by Enriching CD8+ T Cells While Inhibiting Eosinophilia.

Cyclophosphamide (CTX) is widely applied in cancer treatment. However, the outcome is often compromised by lymphopenia, myelosuppression, and gut dysbiosis. Here, we used jujube powder to enhance CTX efficiency through nurturing gut microbiota in order to facilitate favorable metabolisms. It was observed that the oral administration of jujube powder enriched CD8+ T cells in mouse MC38 colon tumor microenvironment and increased the diversity of gut microbiota and the abundance of Bifidobacteriales, which is helpful to the production of butyrate in the cecum content. The application of jujube powder also stimulated the production of white blood cells, especially CD8+ T cells in peripheral and bone marrow, while inhibiting the growth of eosinophils in peripheral blood and the production of IL-7 and GM-CSF in serum. All these are conductive to the significant inhibition of the tumor growth, suggesting the high potential of nurturing gut microbiota with natural products for improving the efficiency of chemotherapy.

Optimal combination treatment regimens of vaccine and radiotherapy augment tumor-bearing host immunity.

A major obstacle to immunotherapy is insufficient infiltration of effector immune cells into the tumor microenvironment. Radiotherapy greatly reduces tumor burden but relapses often occur. Here we show that the immunosuppressive tumor microenvironment was gradually established by recruiting Tregs after radiation. Despite tumors being controlled after depletion of Tregs in the irradiated area, improvement of mice survival remained poor. A much better antitumor effect was achieved with vaccination followed by radiation than other treatments. Vaccination followed by radiation recruited more effector T cells in tumor regions, which responded to high levels of chemokines. Sequential combination of vaccination and radiotherapy could elicit distinct host immune responses. Our study demonstrated that optimal combination of irradiation and vaccination is required to achieve effective antitumor immune responses. We propose a combination regimen that could be easily translated into the clinic and offer an opportunity for rational combination therapies design in cancer treatment.

Glycosylation of anthocyanins enhances the apoptosis of colon cancer cells by handicapping energy metabolism.

BACKGROUND: While anthocyanins are proven to be effective in inhibiting tumour cell proliferation, the underlying mechanisms remain unclear. This research aims to explore the glycosylation of anthocyanins in the tumour inhibitory effects and the potential mechanism. METHODS: The tumour inhibitory effect on mouse colon cancer cells (MC38) was examined by MTT and flow cytometric analyses. The inhibitory pathway of anthocyanin was explored by assessment of tumour cell mitochondrial membrane potential (MMP), the caspase-3 and caspase-9 activity, as well as the cell energy metabolism in terms of the glucose uptake, the NAD+/NADH ratio and the ATP level. RESULTS: We found that 500 µM bilberry anthocyanins extract (BAE) induced 48.1% mitochondrial damage, activated the downstream caspase cascade to form apoptotic bodies (caspase-3 activity increased by 169%, caspase-9 activity increased by 186%), and inhibited cell proliferation (survival rate: 55.97%, 24 h). In contrast, the same concentration of anthocyanidin (cyanidin) led to marginal mitochondrial damage (only 9.85%) and resulted in little inhibition of MC38 cells (survival rate: 86.84%, 24 h). For cells incubated with 500 µM BAE, reactive oxygen species (ROS) decreased by 53.8%, but the ratio of NAD+/NADH increased to 3.67, demonstrating that the mitochondrial damage was induced by blocking energy metabolism. Furthermore, cell energy metabolism is related to glucose uptake since the presence of 200 µM GLUT1 inhibitor substantially enhanced the inhibitory effects of cyanidin-3-O-glucoside (Cy-3-Glu) at 500 µM (survival rate: 51.08%, 24 h). CONCLUSIONS: The study suggested that the glycosides of anthocyanins might handicap glucose transport and inhibit energy metabolism, which, in turn, led to mitochondrial damage and apoptosis of tumour cells.

PPARα Inhibition Overcomes Tumor-Derived Exosomal Lipid-Induced Dendritic Cell Dysfunction.

Dendritic cells (DCs) orchestrate the initiation, programming, and regulation of anti-tumor immune responses. Emerging evidence indicates that the tumor microenvironment (TME) induces immune dysfunctional tumor-infiltrating DCs (TIDCs), characterized with both increased intracellular lipid content and mitochondrial respiration. The underlying mechanism, however, remains largely unclear. Here, we report that fatty acid-carrying tumor-derived exosomes (TDEs) induce immune dysfunctional DCs to promote immune evasion. Mechanistically, peroxisome proliferator activated receptor (PPAR) α responds to the fatty acids delivered by TDEs, resulting in excess lipid droplet biogenesis and enhanced fatty acid oxidation (FAO), culminating in a metabolic shift toward mitochondrial oxidative phosphorylation, which drives DC immune dysfunction. Genetic depletion or pharmacologic inhibition of PPARα effectively attenuates TDE-induced DC-based immune dysfunction and enhances the efficacy of immunotherapy. This work uncovers a role for TDE-mediated immune modulation in DCs and reveals that PPARα lies at the center of metabolic-immune regulation of DCs, suggesting a potential immunotherapeutic target.

Bilberry anthocyanin extracts enhance anti-PD-L1 efficiency by modulating gut microbiota.

The undesirable low response rate is a major hurdle to garnering the maximum potential of immune checkpoint inhibitors in cancer treatments. Recent advances in exploring the effects of intestinal flora on the medical efficacy of immune checkpoint blockade have shed new light on the application of immune checkpoint inhibitors. Inspired by the prebiotic role of anthocyanin-rich extracts, we propose using bilberry anthocyanin extracts to modulate the composition of gut microbiota and eventually, promote the efficiency of immune checkpoint inhibitors. This study demonstrates the effectiveness of orally administered bilberry anthocyanin extracts in enhancing the anti-tumor efficiency of the PD-L1 antibody in the experimental mouse MC38 tumor model. We observed an increase in the fecal abundance of Clostridia and Lactobacillus johnsonii and improved effective community diversity. These findings reinforce the importance of intestinal flora composition and open up unprecedented opportunities in using natural compounds to enhance the efficacy of immune checkpoint inhibitors.