β-Caryophyllene Inhibits Oxaliplatin-Induced Peripheral Neuropathy in Mice: Role of Cannabinoid Type 2 Receptors, Oxidative Stress and Neuroinflammation

Peripheral neuropathy is an important adverse effect caused by some chemotherapeutic agents, including oxaliplatin (OXA). OXA-induced peripheral neuropathy (OIPN) is a challenging condition due to diagnostic complexities and a lack of effective treatment. In this study, we investigated the antiallodynic effect of β-caryophyllene (BCP), a cannabinoid type 2 (CB2) receptor agonist, in a mouse model of OIPN. BCP treatment inhibited OXA-induced mechanical and cold allodynia in both preventive and therapeutic drug treatment regimens. Experiments with the CB2 receptor agonist GW405833 confirmed the role of CB2 receptors in OIPN. The CB2 antagonist SR144528 abrogated the anti-nociceptive effect of BCP on mechanical allodynia, without impacting OXA-induced sensitivity to cold. BCP decreased neuroinflammation, as inferred from TNF, IL-1β, IL-6, and IL-10 profiling, and also reduced ROS production, lipid peroxidation, and 4-hydroxynonenal protein adduct formation in the spinal cords of OXA-treated mice. BCP did not affect the antitumor response to OXA or its impact on blood cell counts, implying that the cytotoxicity of OXA was preserved. These results underscore BCP as a candidate drug for OIPN treatment via CB2 receptor-dependent mechanisms, and anti-inflammatory and antioxidant responses in the spinal cord.

Omics-based identification of an NRF2-related auranofin resistance signature in cancer: Insights into drug repurposing

Auranofin is a thioredoxin reductase-1 inhibitor originally approved for the treatment of rheumatoid arthritis. Recently, auranofin has been repurposed as an anticancer drug, with pharmacological activity reported in multiple cancer types. In this study, we characterized transcriptional and genetic alterations associated with auranofin response in cancer. By integrating data from an auranofin cytotoxicity screen with transcriptome profiling of lung cancer cell lines, we identified an auranofin resistance signature comprising 29 genes, most of which are classical targets of the transcription factor NRF2, such as genes involved in glutathione metabolism (GCLC, GSR, SLC7A11) and thioredoxin system (TXN, TXNRD1). Pan-cancer analysis revealed that mutations in NRF2 pathway genes, namely KEAP1 and NFE2L2, are strongly associated with overexpression of the auranofin resistance gene set. By clustering cancer types based on auranofin resistance signature expression, hepatocellular carcinoma, and a subset of non-small cell lung cancer, head-neck squamous cell carcinoma, and esophageal cancer carrying NFE2L2/KEAP1 mutations were predicted resistant, whereas leukemia, lymphoma, and multiple myeloma were predicted sensitive to auranofin. Cell viability assays in a panel of 20 cancer cell lines confirmed the augmented sensitivity of hematological cancers to auranofin; an effect associated with dependence upon glutathione and decreased expression of NRF2 target genes involved in GSH synthesis and recycling (GCLC, GCLM and GSR) in these cancer types. In summary, the omics-based identification of sensitive/resistant cancers and genetic alterations associated with these phenotypes may guide an appropriate repurposing of auranofin in cancer therapy.

In vitro and in silico trichomonacidal activity of 2,8-bis(trifluoromethyl) quinoline analogs against Trichomonas vaginalis

Trichomoniasis is a great public health burden worldwide and the increase in treatment failures has led to a need for finding alternative molecules to treat this disease. In this study, we present in vitro and in silico analyses of two 2,8-bis(trifluoromethyl) quinolines (QDA-1 and QDA-2) against Trichomonas vaginalis. For in vitro trichomonacidal activity, up to seven different concentrations of these drugs were tested. Molecular docking, biochemical, and cytotoxicity analyses were performed to evaluate the selectivity profile. QDA-1 displayed a significant effect, completely reducing trophozoites viability at 160 µM, with an IC₅₀ of 113.8 µM, while QDA-2 at the highest concentration reduced viability by 76.9%. QDA-1 completely inhibited T. vaginalis growth and increased reactive oxygen species production and lipid peroxidation after 24 h of treatment, but nitric oxide accumulation was not observed. In addition, molecular docking studies showed that QDA-1 has a favorable binding mode in the active site of the T. vaginalis enzymes purine nucleoside phosphorylase, lactate dehydrogenase, triosephosphate isomerase, and thioredoxin reductase. Moreover, QDA-1 presented a level of cytotoxicity by reducing 36.7% of Vero cells' viability at 200 µM with a CC₅₀ of 247.4 µM and a modest selectivity index. In summary, the results revealed that QDA-1 had a significant anti-T. vaginalis activity. Although QDA-1 had detectable cytotoxicity, the concentration needed to eliminate T. vaginalis trophozoites is lower than the CC₅₀ encouraging further studies of this compound as a trichomonacidal agent.

Abstract P5-10-03: Mutant p53 and ERK1/2 MAPK cooperate with the production of TNBC inflammatory secretome

TP53 is the most frequently mutated gene in most types of human cancer, including breast cancer. The triple-negative breast cancer (TNBC) subtype in particular displays TP53 mutation in approximately 80% of patients. Unlike other breast cancer subtypes (e.g., ER/PR-positive or HER2-positive), TNBC patients currently lack an approved highly effective targeted therapy. Notably, most TNBC acquires TP53 mutations, which, in addition to the loss of canonical p53 functions, can result in gain-of-function, activating different cellular mechanisms involved in tumor phenotypes such as proliferation, metastasis, invasiveness, and angiogenesis. Here we evaluate the role of mutant p53 in cancer phenotypes of TNBC cell lines, in particular their inflammatory profile. As expected, loss of p53 protein by small interfering RNA depletion did not show a major impact on the cell viability of MDA-MB231 and Hs578t cells in MTT assay. However, depleting mutant p53 knockdown made MDA-MB231 cells more susceptible to treatment with methyl-methane sulfonate, a genotoxic alkylating agent. Interestingly, cell invasion as measured by the transwell assay demonstrated that depletion of mutant p53 depletion decreased the invasiveness potential of MDA-MB231 and Hs578t cells which was substantiated with decreased migration of MDA-MB231 cells in a scratch assay over 24 h. RNA sequencing of MDA-MB231 and Hs578t cells revealed that mutant p53 knockdown decreased the expression of several constitutively expressed pro-inflammatory cytokines such as IL8, IL6, CXCL2, and CXCL3, but not genes associated with survival to alkylating agents (NRF2 and Endoplasmic reticulum stress markers) or genes typically regulated by wild-type p53 when compared to control-silenced and MMS-treated cells as indicated by Pathway Enrichment Analysis using the Enrich R and DAVID tools. These results were confirmed by ELISA quantification of IL8, IL6, and CXCL2 in MDA-MB231 and Hs578t transfected with two sequences of siRNA targeting mutant p53. On the other hand, RNA sequencing revealed some constitutively expressed genes known to be involved in breast cancer cells malignancy, such as PTGS2 (COX-2 enzyme gene) and MMP1, which were not affected by p53 knockdown. We found that MMP1, and PGE2 (the product of PTGS2/COX-2 enzyme), are upregulated by the ERK1/2 MAPK signaling pathway as determined in MDA-MB231 cells treated with the MEK1/2 inhibitor UO126 and sorafenib. UO126 and sorafenib also decreased IL8 and IL6 production. Furthermore, combined mutant p53 knockdown with MEK/ERK1/2 pathway inhibition caused a more pronounced IL8 and IL6 inhibition when compared to either p53 knockdown or UO126/sorafenib alone, whereas MMP1 and PGE2 levels were only reduced by MEK/ERK1/2 inhibitor treatments. Interestingly, neither mutant p53 knockdown impacted ERK1/2 phosphorylation status nor did UO126/sorafenib alter mutant p53 immunocontent. Reporter assays showed that mutant p53 promotes NFkappaB reporter activation, and MEK/ERK1/2 controls both NFkappaB and AP-1 transcription factors, both associated with the expression of the secretome components evaluated herein. Functional cell assays showed that concomitant inhibition of mutant p53 and MEK/ERK1/2 pathways reduce cell proliferation, invasion, and migration, indicating that mutant p53 protein gain of function cooperates with ERK1/2 MAPK signaling pathway to promote secretome production and malignant phenotypes in TNBC cell models.

Citation Format: Raquel Nascimento das Neves, Aparna Gorthi, Alexander James Roy Bishop, Alfeu Zanotto Filho. Mutant p53 and ERK1/2 MAPK cooperate with the production of TNBC inflammatory secretome [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-10-03.

Thioredoxin reductase-1 levels are associated with NRF2 pathway activation and tumor recurrence in non-small cell lung cancer

Activating mutations in the KEAP1/NRF2 pathway characterize a subset of non-small cell lung cancer (NSCLC) associated with chemoresistance and poor prognosis. We herein evaluated the relationship between 64 oxidative stress-related genes and overall survival data from 35 lung cancer datasets. Thioredoxin reductase-1 (TXNRD1) stood out as the most significant predictor of poor outcome. In a cohort of NSCLC patients, high TXNRD1 protein levels correlated with shorter disease-free survival and distal metastasis-free survival post-surgery, including a subset of individuals treated with platinum-based adjuvant chemotherapy. Bioinformatics analysis revealed that NSCLC tumors harboring genetic alterations in the NRF2 pathway (KEAP1, NFE2L2 and CUL3 mutations, and NFE2L2 amplification) overexpress TXNRD1, while no association with EGFR, KRAS, TP53 and PIK3CA mutations was found. In addition, nuclear accumulation of NRF2 overlapped with upregulated TXNRD1 protein in NSCLC tumors. Functional cell assays and gene dependency analysis revealed that NRF2, but not TXNRD1, has a pivotal role in KEAP1 mutant cells' survival. KEAP1 mutants overexpress TXNRD1 and are less susceptible to the cytotoxic effects of the TXNRD1 inhibitor auranofin when compared to wild-type cell lines. Inhibition of NRF2 with siRNA or ML-385, and glutathione depletion with buthionine-sulfoximine, sensitized KEAP1 mutant A549 cells to auranofin. NRF2 knockdown and GSH depletion also augmented cisplatin cytotoxicity in A549 cells, whereas auranofin had no effect. In summary, these findings suggest that TXNRD1 is not a key determinant of malignant phenotypes in KEAP1 mutant cells, although this protein can be a surrogate marker of NRF2 pathway activation, predicting tumor recurrence and possibly other aggressive phenotypes associated with NRF2 hyperactivation in NSCLC.

Antioxidants Improve Oxaliplatin-Induced Peripheral Neuropathy in Tumor-Bearing Mice Model: Role of Spinal Cord Oxidative Stress and Inflammation

Chemotherapy-Induced Peripheral Neuropathy (CIPN) is a common, difficult-to-treat, and dose-limiting side effect associated with Oxaliplatin (OXA) treatment. In this study, we evaluated the effect of three antioxidants - namely N-acetylcysteine, α-lipoic acid and vitamin E - upon nociceptive parameters and antitumor efficacy of OXA in a tumor-bearing Swiss mice model. Oral treatment with antioxidants inhibited both mechanical and cold allodynia when concomitantly administrated with OXA (preventive protocol), as well as in animals with previously established CIPN (therapeutic protocol). OXA increased Reactive Oxygen Species (ROS) production and lipoperoxidation, and augmented the content of pro-inflammatory cytokines (IL-1β and TNF-α) and expression of the astrocytic marker Gfap mRNA in the spinal cord. Antioxidants decreased ROS production and lipoperoxidation, and abolished neuroinflammation in OXA-treated animals. Toll-like receptor 4 (Tlr4) and inflammasome enzyme caspase-1/11 knockout mice treated with OXA showed reduced levels of pro-inflammatory cytokines (but not oxidative stress) in the spinal cord, which were associated with resistance to OXA-induced mechanical allodynia. Lastly, antioxidants affected neither antitumor activity nor hematological toxicity of OXA in vivo. The herein presented results are provocative for further evaluation of antioxidants in clinical management of chemotherapy-induced peripheral neuropathy. PERSPECTIVE: This study reports preventive and therapeutic efficacy of orally administrated antioxidants (N-acetylcysteine, α-lipoic-acid and Vitamin-E) in alleviating oxaliplatin-induced peripheral neuropathy in tumor-bearing mice. Antioxidants' anti-nociceptive effects are associated with inhibition of ROS-dependent neuroinflammation, and occur at no detriment of OXA antitumor activity, therefore indicating a translational potential of these compounds.

Antiparasitic activity of furanyl N-acylhydrazone derivatives against Trichomonas vaginalis: in vitro and in silico analyses

Background

Trichomonas vaginalis is the causative agent of trichomoniasis, which is one of the most common sexually transmitted diseases worldwide. Trichomoniasis has a high incidence and prevalence and is associated with serious complications such as HIV transmission and acquisition, pelvic inflammatory disease and preterm birth. Although trichomoniasis is treated with oral metronidazole (MTZ), the number of strains resistant to this drug is increasing (2.5–9.6%), leading to treatment failure. Therefore, there is an urgent need to find alternative drugs to combat this disease.

Methods

Herein, we report the in vitro and in silico analysis of 12 furanyl N-acylhydrazone derivatives (PFUR 4, a-k) against Trichomonas vaginalis. Trichomonas vaginalis ATCC 30236 isolate was treated with seven concentrations of these compounds to determine the minimum inhibitory concentration (MIC) and 50% inhibitory concentration (IC₅₀). In addition, compounds that displayed anti-T. vaginalis activity were analyzed using thiobarbituric acid reactive substances (TBARS) assay and molecular docking. Cytotoxicity analysis was also performed in CHO-K1 cells.

Results

The compounds PFUR 4a and 4b, at 6.25 µM, induced complete parasite death after 24 h of exposure with IC₅₀ of 1.69 µM and 1.98 µM, respectively. The results showed that lipid peroxidation is not involved in parasite death. Molecular docking studies predicted strong interactions of PFUR 4a and 4b with T. vaginalis enzymes, purine nucleoside phosphorylase, and lactate dehydrogenase, while only PFUR 4b interacted in silico with thioredoxin reductase and methionine gamma-lyase. PFUR 4a and 4b led to a growth inhibition (< 20%) in CHO-K1 cells that was comparable to the drug of choice, with a promising selectivity index (> 7.4).

Conclusions

Our results showed that PFUR 4a and 4b are promising molecules that can be used for the development of new trichomonacidal agents for T. vaginalis.

2'-Hydroxychalcones as an alternative treatment for trichomoniasis in association with metronidazole

The treatment for trichomoniasis, based on 5'-nitroimidazol agents, has been presenting failures related to allergic reactions, side effects, and the emergence of resistant isolates. There are no alternative drugs approved for the treatment of these cases; thus, the search for new active molecules is necessary. In this scenario, chalcones have been extensively studied for their promising biological activities. Here, we presented the synthesis of three hydroxychalcones (3a, b, and c), in vitro and in silico analyses against Trichomonas vaginalis. The in vitro biological evaluation showed that hydroxychalcone 3c presented anti-T. vaginalis activity, with complete death in 12 h of incubation at minimum inhibitory concentration (MIC) of 100 μM. 3c showed a dose-dependent cytotoxicity against mammalian VERO cell line, but the association of 3c at 12.5 μM and metronidazole (MTZ) at 40 μM showed 95.31% activity against T. vaginalis trophozoites after 24 h of exposure and did not affect the VERO cell growth, appearing to be a good alternative. In silico analysis by molecular docking showed that 3c could inhibit the activity of TvMGL (methionine gamma-lyase), TvLDH (lactate dehydrogenase), and TvPNP (purine nucleoside phosphorylase) affecting the T. vaginalis survival and also suggesting a different mechanism of action from MTZ. Therefore, these results propose that hydroxychalcones are promising anti-T. vaginalis agents and must be considered for further investigations regarding trichomoniasis treatment.

Antiparasitic activity of synthetic curcumin monocarbonyl analogues against Trichomonas vaginalis

Trichomoniasis is a parasitic infection caused by Trichomonas vaginalis and it is considered to be the most common non-viral sexually transmitted infection in the world. Since the 1960s, nitroimidazoles such as metronidazole are the drugs of choice for the treatment of trichomoniasis, but many adverse effects and allergic reactions may result from their use. Reports of metronidazole-resistant infections also highlight the importance for the search of new anti-T. vaginalis agents. Considering this, herein we report the anti-T. vaginalis evaluation of 21 synthetic monocarbonyl analogues of curcumin, which itself has been reported to possess antiparasitic potential. From the in vitro analysis of the synthetic molecules, untreated trophozoites, and metronidazole at 100 μM, it was observed that three curcumin analogues (3a, 3e, and 5e) exhibited anti-T. vaginalis activity comparable to metronidazole (no significant statistical difference). Optimal antiparasitic concentrations were determined to be 80 μM and 90 μM for propanone derivatives 3a and 3e, respectively, and 200 μM for cyclohexanone derivative 5e. Kinetic growth curves showed that, after 24 h, the trophozoites were completely inhibited. At the tested concentrations, natural curcumin did not significantly inhibit the growth of trophozoites, therefore demonstrating that the designed synthetic molecules not only have better chemical stability, but also higher anti-T. vaginalis potential. Cytotoxicity analysis, performed on VERO cells, demonstrated low, moderate and high cytotoxic effects for analogues 3e, 5e and 3a, respectively. This study suggests that these analogues possess chemical features of interest to be further explored as alternatives for the treatment of trichomoniasis.

Chemical composition, immunostimulatory, cytotoxic and antiparasitic activities of the essential oil from Brazilian red propolis

Most studies of Brazilian red propolis have explored the composition and biological properties of its ethanolic extracts. In this work, we chemically extracted and characterized the essential oil of Brazilian red propolis (EOP) and assessed its adjuvant, antiparasitic and cytotoxic activities. The chemical composition of EOP was analyzed using gas chromatography with mass spectrometry (GC-MS). EOP was tested for in vitro activity against Trichomonas vaginalis (ATCC 30236 isolate); trophozoites were treated with different concentrations of EOP (ranging from 25 to 500 μg/mL) in order to establish the MIC and IC₅₀ values. A cytotoxicity assay was performed in CHO-K1 cells submitted to different EOP concentrations. BALB/c mice were used to test the adjuvant effect of EOP. The animals were divided in 3 groups and inoculated as follows: 0.4 ng/kg BW EOP (G1); 50 μg of rCP40 protein (G2); or a combination of 0.4 ng/kg BW EOP and 50 μg of rCP40 (G3). Total IgG, IgG1 and IgG2a levels were assessed by ELISA. The major constituent compounds of EOP were methyl eugenol (13.1%), (E)-β-farnesene (2.50%), and δ-amorphene (2.3%). Exposure to EOP inhibited the growth of T. vaginalis, with an IC₅₀ value of 100 μg/mL of EOP. An EOP concentration of 500 μg/mL was able to kill 100% of the T. vaginalis trophozoites. The EOP kinetic growth curve showed a 36% decrease in trophozoite growth after a 12 h exposure to 500 μg/mL of EOP, while complete parasite death was induced at 24 h. With regard to CHO-K1 cells, the CC₅₀ was 266 μg/mL, and 92% cytotoxicity was observed after exposure to 500 μg/mL of EOP. Otherwise, a concentration of 200 μg/mL of EOP was able to reduce parasite proliferation by 70% and was not cytotoxic to CHO-K1 cells. As an adjuvant, a synergistic effect was observed when EOP was combined with the rCP40 protein (G3) in comparison to the administration of each component alone (G1 and G2), resulting in higher concentrations of IgG, IgG1 and IgG2a. EOP is constituted by biologically active components with promising antiparasitic and immunostimulatory activities and can be investigated for the formulation of new vaccines or trichomonacidal drugs.

Antiparasitic activity of 1,3-dioxolanes containing tellurium in Trichomonas vaginalis

The increased prevalence of metronidazole-resistant infections has resulted in a search for alternative drugs for the treatment of trichomoniasis. In the present study, we report the preparation and in vitro activity of three 1,3-dioxolanes that contain tellurium (PTeDOX 01, PTeDOX 02, and PTeDOX 03) against Trichomonas vaginalis. Six concentrations of these compounds were analyzed for in vitro activity against ATCC 30236 isolate of T. vaginalis. PTeDOX 01 reported a cytotoxic effect against 100% of T. vaginalis trophozoites at a final concentration of 90μM with an IC₅₀ of 60μM. The kinetic growth curve of trophozoites indicated that PTeDOX 01 reduced the growth by 22% at a concentration of 90μM after an exposure of 12h, and induced complete parasite death at 24h. It induced cytotoxicity of 44% at 90μM concentration but and had no effect in lower concentrations in a culture of CHO-K1 cells. These results confirmed that PTeDOX 01 is an important drug for the treatment of T. vaginalis, and should be evaluated in other infectious agents as well.