TGF-β and IL-6 family signalling crosstalk: an integrated model

Childhood maltreatment correlates with higher concentration of transforming growth factor beta (TGF-β) in adult patients with major depressive disorder

Transforming growth factor beta (TGF-β), which has a role as a regulatory cytokine, has not been widely investigated in patients with major depressive disorder (MDD) who experienced childhood trauma. The aim of our study was to investigate the differences in circulating TGF-β levels between the patients with major depressive disorder (MDD) with and without child maltreatment (CM) history, and to compare them to the corresponding control subjects' groups (with or without CM). Blood samples were obtained from 55 patients, fulfilling DSM-IV-R criteria for a current MDD episode without psychotic symptoms, and 45 healthy controls, matched for age and gender. Participants were administered the Childhood Trauma Questionnaire (CTQ). Serum TGF-β concentration was determined by enzyme-linked immunosorbent assay. The concentration of TGF-β was significantly higher in patients with MDD with CM history, compared to MDD patients with no CM, as well as both control groups. Furthermore, we have shown that the combined effect of CM history and MDD affected TGF-β levels in adulthood, which was not observed in the control group with CM. These results indicate that MDD patients with the experience of CM have altered immune-regulatory response, and they may constitute a specific subtype within this heterogenic disorder (ecophenotype).

Association of Genetic Polymorphisms and Serum Levels of IL-6 and IL-8 with the Prognosis in Children with Neuroblastoma

Simple Summary

Neuroblastoma (NB) presents diverse biological and clinical characteristics, from spontaneous regression to highly malignant and aggressive unfavorable tumors that condition the therapeutic failure of conventional treatments. The tumorigenesis of NB can be the result of different genetic variants, which can influence the clinical outcome, and the survival of patients who have metastatic tumors is low. The role of cytokines such as interleukin (IL)-6 has been described in the NB microenvironment promoting tumor progression and metastasis. Single nucleotide polymorphism (SNP)-174 G > C in IL-6 and -251 T > A and +781 C > T in IL-8 regulate the expression of these cytokines, and could be associated with the clinical outcome in patients with NB. Our objective was to evaluate the association of the genetic polymorphisms of IL-6 and IL-8, as well as the serum levels of these cytokines in patients with NB, as this will allow the genetic bases of NB to be characterized and understood, in order to predict the outcome of the disease and develop new therapeutic strategies.

Abstract

There is evidence that high circulating levels of IL-6 and IL-8 are markers of a poor prognosis in various types of cancer, including NB. The participation of these cytokines in the tumor microenvironment has been described to promote progression and metastasis. Our objective was to evaluate the prognostic role of genetic polymorphisms and serum levels of IL-6 and IL-8 in a cohort of Mexican pediatric patients with NB. The detection of the SNPs rs1800795 IL-6 and rs4073 and rs2227306 IL-8 was carried out by PCR-RFLP and the levels of cytokines were determined by the ELISA method. We found elevated circulating levels of IL-8 and IL-6 in NB patients compared to the control group. The genotype frequencies of the rs1800795 IL-6 and rs4073 IL-8 variants were different between the patients with NB and the control group. Likewise, the survival analysis showed that the GG genotypes of rs1800795 IL-6 (p = 0.014) and AA genotypes of rs4073 IL-8 (p = 0.002), as well as high levels of IL-6 (p = 0.009) and IL-8 (p = 0.046), were associated with lower overall survival. We confirmed the impact on an adverse prognosis in a multivariate model. This study suggests that the SNPs rs1800795 IL-6 and rs4073 IL-8 and their serum levels could be promising biomarkers of a poor prognosis, associated with overall survival, metastasis, and a high risk in Mexican children with NB.

On-Target Anti-TGF-β Therapies Are Not Succeeding in Clinical Cancer Treatments: What Are Remaining Challenges?

Metastasis is the leading cause of death for cancer patients. During cancer progression, the initial detachment of cells from the primary tumor and the later colonization of a secondary organ are characterized as limiting steps for metastasis. Epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are opposite dynamic multistep processes that enable these critical events in metastasis by altering the phenotype of cancer cells and improving their ability to migrate, invade and seed at distant organs. Among the molecular pathways that promote tumorigenesis in late-stage cancers, transforming growth factor-β (TGF-β) is described as an EMT master inducer by controlling different genes and proteins related to cytoskeleton assembly, cell-cell attachment and extracellular matrix remodeling. Still, despite the successful outcomes of different TGF-β pharmacological inhibitors in cell culture (in vitro) and animal models (in vivo), results in cancer clinical trials are poor or inconsistent at least, highlighting the existence of crucial components in human cancers that have not been properly explored. Here we review most recent findings to provide perspectives bridging the gap between on-target anti-TGF-β therapies in vitro and in pre-clinical models and the poor clinical outcomes in treating cancer patients. Specifically, we focus on (i) the dual roles of TGF-β signaling in cancer metastasis; (ii) dynamic signaling; (iii) functional differences of TGF-β free in solution vs. in exosomes; (iv) the regulatory effects of tumor microenvironment (TME) – particularly by cancer-associated fibroblasts – on TGF-β signaling pathway. Clearly identifying and establishing those missing links may provide strategies to revitalize and clinically improve the efficacy of TGF-β targeted therapies.

Cancer exosome-derived miR-9 and miR-181a promote the development of early-stage MDSCs via interfering with SOCS3 and PIAS3 respectively in breast cancer

We previously identified that the development of early-stage myeloid-derived suppressor cells (eMDSCs) in breast cancer with high IL-6 (IL-6^high) expression was correlated with the SOCS3 deficiency-dependent hyperactivation of the JAK/STAT signaling pathway. However, the regulatory mechanisms have not yet been elucidated. In this study, we aimed to investigate how the posttranscriptional regulation mediated by cancer exosome-derived miRNAs affected the JAK/STAT signaling pathway and the development of eMDSCs. Using miRNA microarray, we screened miR-9 and miR-181a which were exclusively upregulated in eMDSCs and inversely associated with SOCS3 expression. We found both miRNAs promoted the amplification of immature eMDSCs with the strong suppression on T-cell immunity in mice and humans. Furthermore, miR-9 and miR-181a promoted 4T1 tumor growth and immune escape via enhancing eMDSCs infiltration in situ. But miR-9 and miR-181a stimulated eMDSCs development by separately inhibiting SOCS3 and PIAS3, two crucial regulators in the negative feedback loop of the JAK/STAT signaling pathway. Elevated miR-9 and miR-181a in eMDSCs was derived from tumor-derived exosomes, and blocking the exosome release could fully attenuate the miRNA-mediated regulation on eMDSCs development. In summary, our findings indicated that tumor exosome-derived miR-9 and miR-181a activated the JAK/STAT signaling pathway via targeting SOCS3 and PIAS3, respectively, and thus promoted the expansion of eMDSCs which might provide potential therapeutic target for IL-6^high breast cancer treatment.

The double-edged sword role of fibroblasts in the interaction with cancer cells; an agent-based modeling approach

Fibroblasts as key components of tumor microenvironment show different features in the interaction with cancer cells. Although, Normal fibroblasts demonstrate anti-tumor effects, cancer associated fibroblasts are principal participant in tumor growth and invasion. The ambiguity of fibroblasts function can be regarded as two heads of its behavioral spectrum and can be subjected for mathematical modeling to identify their switching behavior. In this research, an agent-based model of mutual interactions between fibroblast and cancer cell was created. The proposed model is based on nonlinear differential equations which describes biochemical reactions of the main factors involved in fibroblasts and cancer cells communication. Also, most of the model parameters are estimated using hybrid unscented Kalman filter. The interactions between two cell types are illustrated by the dynamic modeling of TGFβ and LIF pathways as well as their crosstalk. Using analytical and computational approaches, reciprocal effects of cancer cells and fibroblasts are constructed and the role of signaling molecules in tumor progression or prevention are determined. Finally, the model is validated using a set of experimental data. The proposed dynamic modeling might be useful for designing more efficient therapies in cancer metastasis treatment and prevention.

On-Target Anti-TGF-β Therapies Are Not Succeeding in Clinical Cancer Treatments: What Are Remaining Challenges?

Metastasis is the leading cause of death for cancer patients. During cancer progression, the initial detachment of cells from the primary tumor and the later colonization of a secondary organ are characterized as limiting steps for metastasis. Epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are opposite dynamic multistep processes that enable these critical events in metastasis by altering the phenotype of cancer cells and improving their ability to migrate, invade and seed at distant organs. Among the molecular pathways that promote tumorigenesis in late-stage cancers, transforming growth factor-β (TGF-β) is described as an EMT master inducer by controlling different genes and proteins related to cytoskeleton assembly, cell-cell attachment and extracellular matrix remodeling. Still, despite the successful outcomes of different TGF-β pharmacological inhibitors in cell culture (in vitro) and animal models (in vivo), results in cancer clinical trials are poor or inconsistent at least, highlighting the existence of crucial components in human cancers that have not been properly explored. Here we review most recent findings to provide perspectives bridging the gap between on-target anti-TGF-β therapies in vitro and in pre-clinical models and the poor clinical outcomes in treating cancer patients. Specifically, we focus on (i) the dual roles of TGF-β signaling in cancer metastasis; (ii) dynamic signaling; (iii) functional differences of TGF-β free in solution vs. in exosomes; (iv) the regulatory effects of tumor microenvironment (TME) - particularly by cancer-associated fibroblasts - on TGF-β signaling pathway. Clearly identifying and establishing those missing links may provide strategies to revitalize and clinically improve the efficacy of TGF-β targeted therapies.

Examining multiple cellular pathways at once using multiplex hextuple luciferase assaying

Sensitive simultaneous assessment of multiple signaling pathways within the same cells requires orthogonal reporters that can assay over large dynamic ranges. Luciferases are such genetically encoded candidates due to their sensitivity, versatility, and cost-effectiveness. We expand luciferase multiplexing in post-lysis endpoint luciferase assays from two to six. Light emissions are distinguished by a combination of distinct substrates and emission spectra deconvolution. All six luciferase reporter units are stitched together into one plasmid facilitating delivery of all reporter units through a process we termed solotransfection, minimizing experimental errors. We engineer a multiplex hextuple luciferase assay to probe pathway fluxes through five transcriptional response elements against a control constitutive promoter. We can monitor effects of siRNA, ligand, and chemical compound treatments on their target pathways along with the four other probed cellular pathways. We demonstrate the effectiveness and adaptiveness of multiplex luciferase assaying, and its broad application across different research fields.

Multiplexed detection of luciferase-based sensors in the same sample is challenging and limited by the substrates’ emission spectra. Here the authors establish a system based on three different luciferases and sequential detection to achieve measurements of up to six parameters within the same experiment.