Spider venom administration impairs glioblastoma growth and modulates immune response in a non-clinical model

Isolated Peptide from Spider Venom Modulates Dendritic Cells In Vitro: A Possible Application in Oncoimmunotherapy for Glioblastoma

Dendritic cells (DCs) vaccine is a potential tool for oncoimmunotherapy. However, it is known that this therapeutic strategy has failed in solid tumors, making the development of immunoadjuvants highly relevant. Recently, we demonstrated that Phoneutria nigriventer spider venom (PnV) components are cytotoxic to glioblastoma (GB) and activate macrophages for an antitumor profile. However, the effects of these molecules on the adaptive immune response have not yet been evaluated. This work aimed to test PnV and its purified fractions in DCs in vitro. For this purpose, bone marrow precursors were collected from male C57BL6 mice, differentiated into DCs and treated with venom or PnV-isolated fractions (F1—molecules < 3 kDa, F2—3 to 10 kDa and F3—>10 kDa), with or without costimulation with human GB lysate. The results showed that mainly F1 was able to activate DCs, increasing the activation-dependent surface marker (CD86) and cytokine release (IL-1β, TNF-α), in addition to inducing a typical morphology of mature DCs. From the F1 purification, a molecule named LW9 was the most effective, and mass spectrometry showed it to be a peptide. The present findings suggest that this molecule could be an immunoadjuvant with possible application in DC vaccines for the treatment of GB.

Bioactive peptides from venoms against glioma progression

Venoms are complex mixtures of different molecules and ions. Among them, bioactive peptides have been found to affect cancer hallmarks, such as cell proliferation, cell invasion, cell migration, and can also modulate the immune response of normal and cancer-bearing organisms. In this article, we review the mechanisms of action on these cancer cell features, focusing on bioactive peptides being developed as potential therapeutics for one of the most aggressive and deadly brain tumors, glioblastoma (GB). Novel therapeutic approaches applying bioactive peptides may contribute to multiple targeting of GB and particularly of GB stem cells. Bioactive peptides selectively target cancer cells without harming normal cells. Various molecular targets related to the effects of bioactive peptides on GB have been proposed, including ion channels, integrins, membrane phospholipids and even immunomodulatory treatment of GB. In addition to therapy, some bioactive peptides, such as disintegrins, can also be used for diagnostics or are used as labels for cytotoxic drugs to specifically target cancer cells. Given the limitations described in the last section, successful application in cancer therapy is rather low, as only 3.4% of such peptides have been included in clinical trials and have passed successfully phases I to III. Combined approaches of added bioactive peptides to standard cancer therapies need to be explored using advanced GB in vitro models such as organoids. On the other hand, new methods are also being developed to improve translation from research to practice and provide new hope for GB patients and their families.

Isolated Components From Spider Venom Targeting Human Glioblastoma Cells and Its Potential Combined Therapy With Rapamycin

Glioblastomas (GBs) are responsible for a higher mortality rate among gliomas, corresponding to more than 50% of them and representing a challenge in terms of therapy and prognosis. Peptide-based antineoplastic therapy is a vast and promising field, and these molecules are one of the main classes present in spider venoms. Recently, our research group demonstrated the cytotoxic effects of Phoneutria nigriventer spider venom (PnV) in GBs. The present study aimed to select the purified PnV-components with potential antineoplastic effects, as well as to compare different metabolic conditions. Human GB (NG97) cells were treated with the PnV fractions: F1 (less than 3 kDa), F2 (between 3 and 10 kDa), and F3 (greater than 10 kDa). After treatments, viability (MTT), proliferation (CFSE), death (Annexin V/propidium iodide-PI), and cell cycle (PI) assays were performed. The F1 and F2 fractions in acute periods (1 and 5 h) and low concentrations (0.1 and 1 μg/ml) showed more relevant effects and were repurified in subfractions (SF1–SF11); from these, SF3 and SF4 showed the most significant effects. The previous inhibition of mTOR by rapamycin had a synergistic effect with SFs, reducing cell viability even more significantly than the untreated control. Taken together, the results point to components present in SF3 and SF4 as potential prototypes for the development of new drugs for GB treatment and stimulate studies to use these compounds in combination therapy with a rapamycin-like activity. Future studies will be conducted to characterize, synthesize the molecules, and to evaluate the efficacy and safety in preclinical models.

The SNX-482 peptide from Hysterocrates gigas spider acts as an immunomodulatory molecule activating macrophages

Peptides are molecules that have emerged as crucial candidates for the development of anticancer drugs. Spider venoms are a rich source of peptides (venom peptides - VPs) with biological effects. VPs have been tested as adjuvants in the activation of cells of the immune system with the aim of improving immunotherapies for the treatment of neoplasms. In the present study, the effects of SNX-482, a peptide from the African tarantula Hysterocrates gigas, on macrophages were described. The results showed that the peptide activated M0-macrophages, increasing costimulatory molecules (CD40, CD68, CD80, CD83, CD86) involved in antigen presentation, and also augmenting the checkpoint molecules PD-L1, CTLA-4 and FAS-L; these effects were not concentration-dependent. SNX-482 also increased the release of IL-23 and upregulated the expression of ccr4, ifn-g, gzmb and pdcd1, genes important for the anticancer response. The pretreatment of macrophages with the peptide did not interfere in the modulation of T cells, and macrophages previously polarized to M1 and M2 profile did not respond to SNX-482. These findings represent the expansion of knowledge about the use of VPs in drug discovery, pointing to a potential new candidate for anticancer immunotherapy. Considering that most immunotherapies target the adaptive system, the modulation of macrophages (an innate immune cell) by SNX-482 is especially relevant.

Anti-inflammatory activities of arthropod peptides: a systematic review

Peptides obtained from different animal species have gained importance recently due to research that aims to develop biopharmaceuticals with therapeutic potential. In this sense, arthropod venoms have drawn attention, not only because of their toxicity but mainly for the search for molecules with various bioactivities, including anti-inflammatory activity. The purpose of the present study is to gather data available in the literature on new peptides derived from arthropod species with anti-inflammatory potential. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Studies on peptides from arthropods that display anti-inflammatory activity were retrieved from PubMed, Scopus, Web of Science, and Google Scholar databases. The bibliographic research started in 2020 and searched papers without a limit on the publication date. The articles were analyzed using a search string containing the following terms: "Peptides" and "Anti-inflammatory", in combinations such as "Ant", "Bee", "Wasp", "Crab", "Shrimp", "Scorpion", "Spider", "Tick" and "Centipedes". Besides, a search was carried out in the databases with the terms: "Peptides", "Antitumor", or "Anticancer", and "Arthropods". Articles that met the inclusion and exclusion criteria totalized 171, and these served for data extraction. Additionally, the present review included anti-inflammatory peptides with anticancer properties. Peptides with confirmed anti-inflammatory activity were from insects (ants, bees, and wasps), crustaceans (shrimp and crabs), arachnids (scorpions, spiders, and ticks), and centipedes. These arthropod peptides act mainly by decreasing pro-inflammatory cytokines as analyzed in vitro and in vivo. Some showed significant antineoplastic activity, working in essential cellular pathways against malignant neoplasms.

Components from spider venom activate macrophages against glioblastoma cells: new potential adjuvants for anticancer immunotherapy

Immunomodulation has been considered an important approach in the treatment of malignant tumors. However, the modulation of innate immune cells remains an underexplored tool. Studies from our group demonstrated that the Phoneutria nigriventer spider venom (PnV) administration increased the infiltration of macrophage in glioblastoma, in addition to decreasing the tumor size in a preclinical model. The hypothesis that PnV would be modulating the innate immune system led us to the main objective of the present study: to elucidate the effects of PnV and its purified fractions on cultured macrophages. Results showed that PnV and the three fractions activated macrophages differentiated from bone marrow precursors. Further purification generated twenty-three subfractions named Low Weight (LW-1 to LW-12) and High Weight (HW-1 to HW-11). LW-9 presented the best immunomodulatory effect. Treated cells were more phagocytic, migrated more, showed an activated morphological profile and induced an increased cytotoxic effect of macrophages on tumor cells. However, while M1-controls (LPS) increased IL-10, TNF-alpha and IL-6 release, PnV, fractions and subfractions did not alter any cytokine, with the exception of LW-9 that stimulated IL-10 production. These findings suggest that molecules present in LW-9 have the potential to be used as immunoadjuvants in the treatment of cancer.

Immunomodulatory properties of molecules from animal venoms

The immune system can amplify or decrease the strength of its response when it is stimulated by chemical or biological substances that act as immunostimulators, immunosuppressants, or immunoadjuvants. Immunomodulation is a progressive approach to treat a diversity of pathologies with promising results, including autoimmune disorders and cancer. Animal venoms are a mixture of chemical compounds that include proteins, peptides, amines, salts, polypeptides, enzymes, among others, which produce the toxic effect. Since the discovery of captopril in the early 1980s, other components from snakes, spiders, scorpions, and marine animal venoms have been demonstrated to be useful for treating several human diseases. The valuable progress in fields such as venomics, molecular biology, biotechnology, immunology, and others has been crucial to understanding the interaction of toxins with the immune system and its application on immune pathologies. More in-depth knowledge of venoms' components and multi-disciplinary studies could facilitate their transformation into effective novel immunotherapies. This review addresses advances and research of molecules from venoms that have immunomodulatory properties.

Spider venom components decrease glioblastoma cell migration and invasion through RhoA-ROCK and Na+/K+-ATPase β2: potential molecular entities to treat invasive brain cancer

BACKGROUND

Glioblastoma (GB) cells have the ability to migrate and infiltrate the normal parenchyma, leading to the formation of recurrent tumors often adjacent to the surgical extraction site. We recently showed that Phoneutria nigriventer spider venom (PnV) has anticancer effects mainly on the migration of human GB cell lines (NG97 and U-251). The present work aimed to investigate the effects of isolated components from the venom on migration, invasiveness, morphology and adhesion of GB cells, also evaluating RhoA-ROCK signaling and Na⁺/K⁺-ATPase β2 (AMOG) involvement.

METHODS

Human (NG97) GB cells were treated with twelve subfractions (SFs-obtained by HPLC from PnV). Migration and invasion were evaluated by scratch wound healing and transwell assays, respectively. Cell morphology and actin cytoskeleton were shown by GFAP and phalloidin labeling. The assay with fibronectin coated well plate was made to evaluate cell adhesion. Western blotting demonstrated ROCK and AMOG levels and a ROCK inhibitor was used to verify the involvement of this pathway. Values were analyzed by the GraphPad Prism software package and the level of significance was determinate using one-way analysis of variance (ANOVA) followed by Dunnett's multiple comparisons test.

RESULTS

Two (SF1 and SF11) of twelve SFs, decreased migration and invasion compared to untreated control cells. Both SFs also altered actin cytoskeleton, changed cell morphology and reduced adhesion. SF1 and SF11 increased ROCK expression and the inhibition of this protein abolished the effects of both subfractions on migration, morphology and adhesion (but not on invasion). SF11 also increased Na⁺/K⁺-ATPase β2.

CONCLUSION

All components of the venom were evaluated and two SFs were able to impair human glioblastoma cells. The RhoA effector, ROCK, was shown to be involved in the mechanisms of both PnV components. It is possible that AMOG mediates the effect of SF11 on the invasion. Further investigations to isolate and biochemically characterize the molecules are underway.