Plant extracts modulate cellular stress to inhibit replication of mouse Coronavirus MHV-A59

The Covid-19 infection outbreak led to a global epidemic, and although several vaccines have been developed, the appearance of mutations has allowed the virus to evade the immune response. Added to this is the existing risk of the appearance of new emerging viruses. Therefore, it is necessary to explore novel antiviral therapies. Here, we investigate the potential in vitro of plant extracts to modulate cellular stress and inhibit murine hepatitis virus (MHV)-A59 replication. L929 cells were treated with P2Et (Caesalpinia spinosa) and Anamu SC (Petiveria alliacea) plant extracts during infection and virus production, ROS (reactive oxygen species), UPR (unfolded protein response), and autophagy were assessed. P2Et inhibited virus replication and attenuated both ROS production and UPR activation induced during infection. In contrast, the sustained presence of Anamu SC during viral adsorption and replication was required to inhibit viral infection, tending to induce pro-oxidant effects, and increasing UPR gene expression. Notably, the loss of the PERK protein resulted in a slight decrease in virus yield, suggesting a potential involvement of this UPR pathway during replication. Intriguingly, both extracts either maintained or increased the calreticulin surface exposure induced during infection. In conclusion, our findings highlight the development of antiviral natural plant extracts that differentially modulate cellular stress.

Development of a MEK inhibitor, NFX-179, as a chemoprevention agent for squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer. Although cSCC contributes to substantial morbidity and mortality in high-risk individuals, deployment of otherwise effective chemoprevention of cSCC is limited by toxicities. Our systematic computational drug repurposing screen predicted that selumetinib, a MAPK (mitogen-activated protein kinase) kinase inhibitor (MEKi), would reverse transcriptional signatures associated with cSCC development, consistent with our genomic analysis implicating MEK as a chemoprevention target. Although systemic MEKi suppresses the formation of cSCC in mice, systemic MEKi can cause severe adverse effects. Here, we report the development of a metabolically labile MEKi, NFX-179, designed to potently and selectively suppress the MAPK pathway in the skin before rapid metabolism in the systemic circulation. NFX-179 was identified on the basis of its biochemical and cellular potency, selectivity, and rapid metabolism upon systemic absorption. In our ultraviolet-induced cSCC mouse model, topical application of NFX-179 gel reduced the formation of new cSCCs by an average of 60% at doses of 0.1% and greater at 28 days. We further confirmed the localized nature of these effects in an additional split-mouse randomized controlled study where suppression of cSCC was observed only in drug-treated areas. No toxicities were observed. NFX-179 inhibits the growth of human SCC cell lines in a dose-dependent manner, and topical NFX-179 application penetrates human skin and inhibits MAPK signaling in human cSCC explants. Together, our data provide a compelling rationale for using topical MEK inhibition through the application of NFX-179 gel as an effective strategy for cSCC chemoprevention.

Microbiome modulates immunotherapy response in cutaneous squamous cell carcinoma

The gut microbiome is increasingly recognized to alter cancer risk, progression and response to treatments such as immunotherapy, especially in cutaneous melanoma. However, whether the microbiome influences immune checkpoint inhibitor (ICI) immunotherapy response to non-melanoma skin cancer has not yet been defined. As squamous cell carcinomas (SCC) are in closest proximity to the skin microbiome, we hypothesized that the skin microbiome, which regulates cutaneous immunity, might affect SCC-associated anti-PD1 immunotherapy treatment response. We used ultraviolet radiation to induce SCC in SKH1 hairless mice. We then treated the mice with broad-band antibiotics to deplete the microbiome, followed by colonisation by candidate skin and gut bacteria or persistent antibiotic treatment, all in parallel with ICI treatment. We longitudinally monitored skin and gut microbiome dynamics by 16S rRNA gene sequencing and tumour burden by periodic tumour measurements and histologic assessment. Our study revealed that antibiotics-induced abrogation of the microbiome reduced the tumour burden, suggesting a functional role of the microbiome in non-melanoma skin cancer therapy response.

Modulation of Myeloid-Derived Suppressor Cells in the Tumor Microenvironment by Natural Products

During carcinogenesis, the microenvironment plays a fundamental role in tumor progression and resistance. This tumor microenvironment (TME) is characterized by being highly immunosuppressive in most cases, which makes it an important target for the development of new therapies. One of the most important groups of cells that orchestrate immunosuppression in TME is myeloid-derived suppressor cells (MDSCs), which have multiple mechanisms to suppress the immune response mediated by T lymphocytes and thus protect the tumor. In this review, we will discuss the importance of modulating MDSCs as a therapeutic target and how the use of natural products, due to their multiple mechanisms of action, can be a key alternative for modulating these cells and thus improve response to therapy in cancer patients.

Plant extract from Caesalpinia spinosa inhibits cancer-associated fibroblast-like cells generation and function in a tumor microenvironment model

Interactions in the tumor microenvironment (TME) between tumor cells and stromal cells such as cancer-associated fibroblasts (CAF) favor increased survival, progression, and transformation of cancer cells by activating mechanisms of invasion and metastasis. The design of new therapies to modulate or eliminate the CAF phenotype or functionality has been the subject of recent research including natural product-based therapies. We have previously described the generation of a standardized extract rich in polyphenols obtained from the Caesalpinia spinosa plant (P2Et), which present antitumor activities in breast cancer and melanoma models through activities that modulate the metabolism of tumor cells or induce the development of the immune response. In this work, a model of CAF generation was initially developed from the exposure of 3T3 fibroblasts to the cytokine TGFβ1. CAF-like cells generated in this way exhibited changes in the expression of Caveolin-1 and α-SMA, and alterations in glucose metabolism and redox status, typical of CAFs isolated from tumor tissues. Then, P2Et was shown to counteract in vitro-induced CAF-like cell generation, preventing caveolin-1 loss and attenuating changes in glucose uptake and redox profile. This protective effect of P2Et translates into a decrease in the functional ability of CAFs to support colony formation and migration of 4T1 murine breast cancer tumor cells. In addition to the functional interference, the P2Et extract also decreased the expression of genes associated with the epithelial-mesenchymal transition (EMT) and functional activities related to the modulation of the cancer stem cells (CSC) population. This work is an in vitro approach to evaluate natural extracts' effect on the interaction between CAF and tumor cells in the tumor microenvironment; thus, these results open the chance to design a more profound and mechanistic analysis to explore the molecular mechanisms of P2Et multimolecular activity and extent this analysis to an in vivo perspective. In summary, we present here a standardized polymolecular natural extract that has the potential to act in the TME by interfering with CAF generation and functionality.

Microbiome modulates immunotherapy response in cutaneous squamous cell carcinoma

The gut microbiome is increasingly recognized to alter cancer risk, progression, and response to treatments such as immunotherapy, especially in cutaneous melanoma. However, whether the microbiome influences immune checkpoint inhibitor (ICI) immunotherapy response to non-melanoma skin cancer has not yet been defined. As squamous cell carcinomas (SCC) are in closest proximity to the skin microbiome, we hypothesized that the skin microbiome, which regulates cutaneous immunity, might affect SCC-associated anti-PD1 immunotherapy treatment response. We used ultraviolet radiation to induce SCC in SKH1 hairless mice. We then treated the mice with broad-band antibiotics to deplete the microbiome, followed by colonization by candidate skin and gut bacteria or persistent antibiotic treatment, all in parallel with ICI treatment. We longitudinally monitored skin and gut microbiome dynamics by 16S rRNA gene sequencing, and tumor burden by periodic tumor measurements and histologic assessment. Our study revealed that antibiotics-induced abrogation of the microbiome reduced tumor burden, suggesting a functional role of the microbiome in non-melanoma skin cancer therapy response.

Ablation of the endoplasmic reticulum stress kinase PERK induces paraptosis and type I interferon to promote anti-tumor T cell responses

Activation of unfolded protein responses (UPRs) in cancer cells undergoing endoplasmic reticulum (ER) stress promotes survival. However, how UPR in tumor cells impacts anti-tumor immune responses remains poorly described. Here, we investigate the role of the UPR mediator pancreatic ER kinase (PKR)-like ER kinase (PERK) in cancer cells in the modulation of anti-tumor immunity. Deletion of PERK in cancer cells or pharmacological inhibition of PERK in melanoma-bearing mice incites robust activation of anti-tumor T cell immunity and attenuates tumor growth. PERK elimination in ER-stressed malignant cells triggers SEC61β-induced paraptosis, thereby promoting immunogenic cell death (ICD) and systemic anti-tumor responses. ICD induction in PERK-ablated tumors stimulates type I interferon production in dendritic cells (DCs), which primes CCR2-dependent tumor trafficking of common-monocytic precursors and their intra-tumor commitment into monocytic-lineage inflammatory Ly6C+CD103+ DCs. These findings identify how tumor cell-derived PERK promotes immune evasion and highlight the potential of PERK-targeting therapies in cancer immunotherapy.

Randomized double-blind clinical study in patients with COVID-19 to evaluate the safety and efficacy of a phytomedicine (P2Et)

Background

It has been proposed that polyphenols can be used in the development of new therapies against COVID-19, given their ability to interfere with the adsorption and entrance processes of the virus, thus disrupting viral replication. Seeds from Caesalpinia spinosa, have been traditionally used for the treatment of inflammatory pathologies and respiratory diseases. Our team has obtained an extract called P2Et, rich in polyphenols derived from gallic acid with significant antioxidant activity, and the ability to induce complete autophagy in tumor cells and reduce the systemic inflammatory response in animal models.

Methods

In this work, a phase II multicenter randomized double-blind clinical trial on COVID-19 patients was designed to evaluate the impact of the P2Et treatment on the clinical outcome and the immunological parameters related to the evolution of the disease. The Trial was registered with the number No. NCT04410510^*. A complementary study in an animal model of lung fibrosis was carried out to evaluate in situ lung changes after P2Et in vivo administration. The ability of P2Et to inhibit the viral load of murine and human coronaviruses in cellular models was also evaluated.

Results

Patients treated with P2Et were discharged on average after 7.4 days of admission vs. 9.6 days in the placebo group. Although a decrease in proinflammatory cytokines such as G-CSF, IL-15, IL-12, IL-6, IP10, MCP-1, MCP-2 and IL-18 was observed in both groups, P2Et decreased to a greater extent G-CSF, IL-6 and IL-18 among others, which are related to lower recovery of patients in the long term. The frequency of T lymphocytes (LT) CD3+, LT double negative (CD3+CD4-CD8-), NK cells increased in the P2Et group where the population of eosinophils was also significantly reduced. In the murine bleomycin model, P2Et also reduced lung inflammation and fibrosis. P2Et was able to reduce the viral replication of murine and human coronaviruses in vitro, showing its dual antiviral and anti-inflammatory role, key in disease control.

Conclusions

Taken together these results suggest that P2Et could be consider as a good co-adjuvant in the treatment of COVID-19.

Clinical trail registration

https://clinicaltrials.gov/ct2/show/NCT04410510, identifier: NCT04410510.

The delay in cell death caused by the induction of autophagy by P2Et extract is essential for the generation of immunogenic signals in melanoma cells

P2Et extract obtained from the Caesalpinia spinosa plant is abundant in phenolic compounds such as gallic acid and ethyl gallate and can generate signals to activate the immune response by inducing a mechanism known as immunogenic cell death in murine models of breast cancer and melanoma. Immunogenic cell death involves mechanisms such as autophagy, which can be modulated by various natural compounds, including phenolic compounds with a structure similar to those found in P2Et extract. Here, we determine the role of autophagy in apoptosis and the generation of immunogenic signals using murine wild-type B16-F10 melanoma cells and cells with beclin-1 gene knockout. We show that P2Et extract and ethyl gallate induced autophagy, partially protecting tumor cells from death and promoting calreticulin exposure and the release of ATP. Although ethyl gallate showed a mechanism similar to that of P2Et, the induction of apoptosis and immunogenic signals was significantly weaker. In contrast, gallic acid-induced autophagy acted by blocking autophagic flux, which was associated with increased cell death. However, this compound did not induce any of the immunogenic death signals evaluated. Therefore, the complex extract has greater antitumor potential than isolated compounds. Here, we show that inducing autophagic flux with P2Et protects cancer cells from cell death and that this delay in cell death is required for the generation of immunogenic signals.

Immunodeficiency in a Patient with 22q11.2 Distal Deletion Syndrome and a p.Ala7dup Variant in the MAPK1 Gene

The genetic basis for sporadic immunodeficiency in patients with 22q11.2 distal deletion syndrome is unknown. We report an adult with a type 1 (D-F) 22q11.2 distal deletion syndrome and recurrent severe infections due to herpes zoster virus, presenting mild T cell lymphopenia and diminished frequency of naive CD4⁺ T cells, but increased frequencies of central, effector, and terminally differentiated memory T cells. Antigen-specific CD4⁺ and CD8⁺ T cells to influenza, rotavirus, and SEB were conserved in the patient, but responses to tetanus toxoid were temporarily undetectable. Exomic sequencing identified the c.20_22dupCGG (NM_002745.4) variant in the remaining MAPK1 gene of the patient, which adds 1 alanine to the polyalanine amino-terminal tract of the protein (p.Ala7dup). The mother, unlike the father, was heterozygote for the variant. Western blot analysis with the patient's activated PBMCs showed a 91% reduction in the MAPK1 protein. Further studies will be necessary to determine whether or not the variant present in the remaining MAPK1 gene of the patient is pathogenic.

Polyphenol-rich extract induces apoptosis with immunogenic markers in melanoma cells through the ER stress-associated kinase PERK

Polyphenols elicit antitumor activities, in part, through the induction of anti- or pro-oxidant effects in cancer cells which promote priming of protective anti-tumor immunity. We recently characterized a polyphenol-rich extract from Caesalpinia spinosa (P2Et) that stimulates in vivo antitumor responses against breast and melanoma tumor models via the promotion of immunogenic cancer cell death (ICD). However, the primary mediators whereby P2Et promotes ICD remained unknown. Here, we sought to elucidate the role that severe endoplasmic reticulum (ER) stress plays in mediating P2Et-induced apoptosis and ICD in murine melanoma cells. Our findings demonstrate a substantial selective induction of specific ER-stress mediators in B16-F10 melanoma cells treated with P2Et. While knockout of the ER stress-associated PKR-like ER kinase (PERK) prevented induction of apoptosis and expression of ICD markers in P2Et-treated cells, deletion of X-box binding protein 1 (Xbp1) did not. P2Et-driven activation of PERK in melanoma cells was found to promote ER-calcium release, disrupt mitochondrial membrane potential, and trigger upregulation of ICD drivers, surface calreticulin expression, and extracellular release of ATP and HMGB1. Notably, calcium release inhibition, but not targeting of PERK-driven integrated stress responses, prevented P2Et-induced apoptosis. Collectively, these results underline the central role of PERK-directed calcium release in mediating the antitumor and immunogenic actions of P2Et in melanoma cells.

[Homocysteine levels and polymorphisms of MTHFR and CBS genes in Colombian patients with superficial and deep venous thrombosis]

INTRODUCTION

Thrombosis develops when the hemostatic system is incorrectly activated due to the unbalance between procoagulant, anticoagulant and fibrinolytic mechanisms allowing the formation of a clot within a blood vessel. The risk factors of this pathology can be acquired or can be genetic.

OBJECTIVES

To analyze in a Colombian population with diagnosis of venous thrombosis, lipid profile, glucose and homocystein levels, to calculate the alleles and genotypic frequencies of polymorphisms c.699 C>T, c.1080 C>T, c.844ins68 of the cystathionine ß synthase and the c.677 C>T of the methylenetetrahydrofolate reductase (MTHFR) genes.

MATERIALS AND METHODS

Thirty three patients and their controls were studied. The biochemical test was carried out by colorimetric methods and immunoassay. In this survey we used the restriction fragments longitude polymorphism (RLFP) technique to identify the polymorphisms mentioned. The association study was performed through the chi square test.

RESULTS

We confirmed that gene alterations increase risk for pathology; we found statistically significant differences in the group with hypercholesterolemia in presence of the polymorphism c.699 C>T in the CBS gene, showing a protective effect in the individuals carrying this genetic variation. Likewise, we found a statistical trend for an eventual protective effect of the CBS c.844ins68 polymorphism to venous thrombotic disease.

CONCLUSIONS

There were not any statistically significant differences in homocystein levels between cases and controls; nevertheless, the variability in the plasma concentrations was greater in the group of cases.

[Effect of miskleron (clofibrate) on dimethylhydrazine induction of intestinal tumors in rats]

In this review, we report on the complexity of breast cancer stem cells as key cells in the emergence of a chemoresistant tumor phenotype, and as a result, the appearance of distant metastasis in breast cancer patients. The search for mechanisms that increase sensitivity to chemotherapy and also allow activation of the tumor-specific immune response is of high priority. As we observed throughout this review, natural products isolated or in standardized extracts, such as P2Et or others, could act synergistically, increasing tumor sensitivity to chemotherapy, recovering the tumor microenvironment, and participating in the induction of a specific immune response. This, in turn, would lead to the destruction of cancer stem cells and the decrease in metastasis.

Source of Data: Relevant studies were found using the following keywords or medical subject headings (MeSH) in PubMed, and Google Scholar: “immune response” and “polyphenols” and “natural products” and “BCSC” and “therapy” and “metabolism” and “immunogenic cell death.” The focus was primarily on the most recent scientific publication.