The antitumor immunopreventive effects of a DNA vaccine against CYP26a1 on mouse breast carcinoma

Immunoprevention of non-viral cancers: challenges and strategies for early intervention

While the effects of cancer vaccines have been extensively studied in the therapeutic setting, research has been more limited in the areas of cancer prevention and interception. Although cancer prevention by vaccines has been possible for viral-mediated cancers, such as cervical cancers and hepatocellular carcinoma, preventing non-viral cancers by immunopreventive vaccines is challenging. Many tumors at late stages are less responsive to treatments, including immunotherapies and vaccines, in part due to an immunosuppressive microenvironment. Shifting the strategy to intervention at early stages of cancer development and progression and focusing on high-risk cohorts with defined molecular targets offers a pathway for improved vaccine efficacy. Current research on the role of immune mechanisms during tumor initiation and progression is rapidly evolving and recent emerging preclinical immunoprevention studies have shown that vaccines can induce host immune response and effectively control tumor onset and progression. In this review, we address important considerations and challenges regarding the development of cancer immunoprevention for non-viral cancers. We also discuss significant, innovative, and impactful preclinical and clinical immunoprevention studies in various cancers. This includes neoantigen discovery, the use and optimization of immunomodulating agents either alone or in combination with vaccines, and strategies for optimizing vaccines. We conclude by discussing prospects for immunoprevention research and potential opportunities to advance the field in the future.

Cardiotoxicity induced by xanthatin via activating apoptosis and ERS pathways in zebrafish

Xanthatin, a sesquiterpene lactone compound, isolated from Chinese herb, Xanthium strumarium L, has various activities, including anti-inflammatory, anti-tumor, anti-ulcer effects. However, it has been less studied in terms of its toxicity, especially the potential toxicity on heart. This study is mainly aimed to assess the cardiotoxicity of xanthatin in vivo using zebrafish larva and in vitro using cardiomyocytes H9C2. The cardiotoxicity in zebrafish was assessed by the pericardial edema, blood flow dynamics, SV-BA distance, and sub-intestinal vein. The apoptosis was determined by AO staining, the blood red cell reduction and distribution was detected by O-dianisidine staining, histopathological evaluations were detected by HE staining. The anti-proliferative and pro-apoptotic activities in H9C2 cells were assessed by EdU staining and Hoechst 33342/PI double staining. The in vivo results showed that xanthatin caused cardiac malformations and dysfunctions, including decreased heart rate, reduced red blood cell count, hemodynamics, stroke volume, increased SV-BA distance and sub-intestinal vein congestion. Furthermore, apoptosis occurred in the heart of the zebrafish after xanthatin exposure. Additionally, cat, Mn-sod, chop, perk, and hspa5 related to oxidative stress and ERS also changed by xanthatin. Apoptotic genes caspase3 and caspase9 were also increased. Moreover, the in vitro results showed that xanthatin had proapoptotic and antiproliferative effects. To sum up, these results suggest that xanthatin has cardiotoxicity and the oxidative stress, ERS and apoptosis pathways are involved in the cardiotoxicity induced by xanthatin. This finding will be helpful for the better understanding of the potential cardiotoxicity of xanthatin and the underlying mechanism.

Developmental toxicity induced by chelerythrine in zebrafish embryos via activating oxidative stress and apoptosis pathways

Chelerythrine (CHE), a natural benzophenanthridine alkaloid, possesses various biological and pharmacological activities, such as antimicrobial, antitumor and anti-inflammatory effects. However, its adverse side effect has not been fully elucidated. Therefore, this study was designed to investigate the developmental toxicity of CHE in zebrafish. We found that CHE could lead to a notably increase of the mortality and malformation rate, while lead to reduction of the hatching rate and body length. CHE also could affect the normal developing processes of the heart, liver and phagocytes in zebrafish. Furthermore, the reactive oxygen species (ROS) and apoptosis levels were notably increased. In addition, the mRNA expressions of genes (bax, caspase-9, p53, SOD1, KEAP1, TNF-α, STAT3 and NF-κB) were significantly increased, while the bcl2 and nrf2 were notably inhibited by CHE. These results indicated that the elevation of ROS and apoptosis were involved in the developmental toxicity induced by CHE. In conclusion, CHE exhibits a developmental toxicity in zebrafish, which helps to understand the potential toxic effect of CHE.

Neurotoxicity of sanguinarine via inhibiting mitophagy and activating apoptosis in zebrafish and PC12 cells

Sanguinarine, a plant-derived phytoalexin, displays various biological activities, such as insecticidal, antimicrobial, anti-inflammatory, anti-angiogenesis and antitumor effects. But its potential neurotoxicity and the underlying mechanisms has rarely been investigated. Therefore, we aimed to assess the neurotoxicity of sanguinarine using zebrafish model and PC12 cells in this study. The results showed that sanguinarine induced the reduction of the length of dopamine neurons and inhibited the blood vessel in the head area of the zebrafish. Further studies demonstrated that the behavioral phenotype of the larval zebrafish was changed by sanguinarine. In addition, there were more apoptotic cells in the larval zebrafish head area. The mRNA expression levels of β-syn, th, pink1 and parkin, closely related to the nervous function, were changed after sanguinarine treatment. The in vitro studies show that notably increases of ROS and apoptosis levels in PC12 cells were observed after sanguinarine treatment. Moreover, the protein expression of Caspase3, Parp, Bax, Bcl2, α-Syn, Th, PINK1 and Parkin were also altered by sanguinarine. Our data indicated that the inhibition of mitophagy, ROS elevation and apoptosis were involved in the neurotoxicity of sanguinarine. These findings will be useful to understand the toxicity induced by sanguinarine.

Cardiotoxicity of sanguinarine via regulating apoptosis and MAPK pathways in zebrafish and HL1 cardiomyocytes

Sanguinarine, a plant phytoalexin, possesses extensive biological activities including antimicrobial, insecticidal, antitumor, anti-inflammatory and anti-angiogenesis effect. But its cardiotoxicity has rarely been studied. Here, we assess the cardiotoxicity of sanguinarine in vivo using larval zebrafish from 48 hpf to 96 hpf. The results show that sanguinarine caused severe malformation and the dysfunction of the heart including reductions of heart rate, red blood cell number, blood flow dynamics, stroke volume and increase of SV-BA distance, subintestinal venous congestion. Further studies showed that apoptosis in the zebrafish heart region was observed after sanguinarine exposure using TUNEL assay and AO staining method. In addition, the genes, such as sox9b, myl7, nkx2.5 and bmp10, which play crucial parts in the development and the function of the heart, were changed after sanguinarine treatment. caspase3, caspase9, bax and bcl2, apoptosis-related genes, were also altered by sanguinarine. Further studies were performed to study the cardiotoxicity in vitro using cardiomyocytes HL1 cell line. The results showed that remarkable increase of apoptosis and ROS level in HL1 cells were induced by sanguinarine. Moreover, the MAPK pathway (JNK and P38) were notably enhanced and involved in the cardiotoxicity induced by sanguinarine. Our findings will provide better understanding of sanguinarine in the toxic effect on heart.

Developmental toxicity caused by sanguinarine in zebrafish embryos via regulating oxidative stress, apoptosis and wnt pathways

Sanguinarine, derived from the root of Sanguinaria canadensis, have multiple biological activities, such as antimicrobial, insecticidal, antitumor, anti-inflammatory and anti-angiogenesis effect, but little is known about its toxicity on normal embryonic development. Here, we study the developmental toxicity using zebrafish model. Notably, sanguinarine caused a significant increase of the malformation rate and decrease of hatching rates and body length of zebrafish embryos. Sanguinarine also impaired the normal development of heart, liver and nerve system of zebrafish embryos. Further, the ROS level and MDA concentrations were remarkably increased, while the activity of T-SOD was decreased. In addition, obvious increase of apoptosis were observed by AO staining or TUNEL assay. Further studies showed that the oxidative stress-, apoptosis-related genes were changed, while genes of nrf2 and wnt pathways were inhibited by sangunarine. To sum up, our study will be helpful to understand the adverse effect of sanguinarine on embryonic development and the underlying molecular mechanism.