Dominant negative TGFβ receptor II and truncated TIM3 enhance the antitumor efficacy of CAR-T-cell therapy in prostate cancer

BACKGROUND

The immune checkpoint molecules, Transforming growth factor beta receptor II (TGFβRII) and T cell immunoglobulin and mucin domain 3 (TIM3), have been identified as contributors to T cell immune suppression in prostate cancer. The objective of this investigation was to improve the tumor killing capability of prostate-specific membrane antigen (PSMA)-chimeric antigen receptor T (CAR-T) cells by targeting TIM3 and TGFβRII simultaneously.

METHODS

To generate dnTGFβRII-trTIM3-PSMA-CAR-T (DT-PSMA-CAR-T) cells, the surface of PSMA-CAR-T cells was overexpressed with dominant negative TGFβRII (dnTGFβRII) and truncated extracellular TIM3 (trTIM3). The efficacy of DT-PSMA-CAR-T cells was assessed through in vitro killing experiments and animal experiments.

RESULTS

The DT-PSMA-CAR-T cells demonstrated the ability to eradicate PSMA-positive prostate cancer cells, even in the presence of exogenous TGF-β and/or TIM3 activating antibodies. In addition, the cells demonstrated the ability to eliminate tumor tissue in an immunodeficient mouse model transplanted with GAL9-PSMA-PC3 cells in vitro, prolonging survival without significant toxic side effects.

CONCLUSIONS

This study emphasizes that upregulating dnTGFβRII and trTIM3 on the surface of T cells can potentially diminish the inhibitory effects of TGFβRII and TIM3.

AAV-mediated expression of galactose-1-phosphate uridyltransferase corrects defects of galactose metabolism in classic galactosemia patient fibroblasts

Classic galactosemia (CG) is a rare disorder of autosomal recessive inheritance. It is caused predominantly by point mutations as well as deletions in the gene encoding the enzyme galactose-1-phosphate uridyltransferase (GALT). The majority of the more than 350 mutations identified in the GALT gene cause a significant reduction in GALT enzyme activity resulting in the toxic buildup of galactose metabolites that in turn is associated with cellular stress and injury. Consequently, developing a therapeutic strategy that reverses both the oxidative and ER stress in CG cells may be helpful in combating this disease. Recombinant adeno-associated virus (AAV)-mediated gene therapy to restore GALT activity offers the potential to address the unmet medical needs of galactosemia patients. Here, utilizing fibroblasts derived from CG patients we demonstrated that AAV-mediated augmentation of GALT protein and activity resulted in the prevention of ER and oxidative stress. We also demonstrate that these CG patient fibroblasts exhibit reduced CD109 and TGFβRII protein levels and that these effectors of cellular homeostasis could be restored following AAV-mediated expression of GALT. Finally, we show initial in vivo proof-of-concept restoration of galactose metabolism in a GALT knockout mouse model following treatment with AAV-GALT.

Prognostic Relevance of Transforming Growth Factor-β Receptor Expression and Signaling in Glioblastoma, Isocitrate Dehydrogenase-Wildtype

The transforming growth factor (TGF)-β signaling pathway has been recognized as a major factor in promoting the aggressive behavior of glioblastoma, isocitrate dehydrogenase-wildtype. However, there is little knowledge about the expression of TGF-β receptors in glioblastoma. Here, we studied the expression patterns of TGF-β receptor II (TGFβRII), type I receptors activin receptor-like kinase (ALK)-5, and ALK-1, as well as of the transcriptional regulators inhibitor of differentiation (Id) 2, Id3, and Id4 in human glioblastoma. The expression of TGFβRII, ALK-5, and ALK-1 varied greatly, with TGFβRII and ALK-5 being the most abundant and ALK-1 being the least expressed receptor. None of the 3 receptors was preferentially expressed by tumor vasculature as opposed to the tumor bulk, indicating tumor bulk-governed mechanisms of TGF-β signaling with regard to glioblastoma-associated angiogenesis. A positive correlation was found between ALK-1 and Id2, suggesting that Id2, broadly expressed in the tumor cells, is a downstream target of this receptor-dependent pathway. Furthermore, there was a trend for high expression of ALK-5 or Id2 to be associated with inferior overall survival. Hence, we propose that ALK-5 may be used for patient stratification in future anti-TGF-β treatment trials and that Id2 might be a potential target for anti-TGF-β interventions.

MicroRNA-30c suppresses the pro-fibrogenic effects of cardiac fibroblasts induced by TGF-β1 and prevents atrial fibrosis by targeting TGFβRII

Atrial fibrosis serves as an important contributor to atrial fibrillation (AF). Recent data have suggested that microRNA-30c (miR-30c) is involved in fibrotic remodelling and cancer development, but the specific role of miR-30c in atrial fibrosis remains unclear. The purpose of this study was to investigate the role of miR-30c in atrial fibrosis and its underlying mechanisms through in vivo and in vitro experiments. Our results indicate that miR-30c is significantly down-regulated in the rat abdominal aortic constriction (AAC) model and in the cellular model of fibrosis induced by transforming growth factor-β1 (TGF-β1). Overexpression of miR-30c in cardiac fibroblasts (CFs) markedly inhibits CF proliferation, differentiation, migration and collagen production, whereas decrease in miR-30c leads to the opposite results. Moreover, we identified TGFβRII as a target of miR-30c. Finally, transferring adeno-associated virus 9 (AAV9)-miR-30c into the inferior vena cava of rats attenuated fibrosis in the left atrium following AAC. These data indicate that miR-30c attenuates atrial fibrosis via inhibition of CF proliferation, differentiation, migration and collagen production by targeting TGFβRII, suggesting that miR-30c might be a novel potential therapeutic target for preventing atrial fibrosis.

Inhibiting post-translational core fucosylation protects against albumin-induced proximal tubular epithelial cell injury

Albuminuria is an independent risk factor for renal interstitial fibrosis (RIF). Glomerular-filtered albumin in endocytic and non-endocytic pathways may injure proximal tubular epithelial cells (PTECs) via megalin and TGFβRII, respectively. Since megalin and TGFβRII are both modified by post-translational core fucosylation, which plays a critical role in RIF. Thus, we sought to identify whether core fucosylation is a potential target for reducing albumin-induced injury to PTECs. We constructed a human PTEC-derived cell line (HK-2 cells) and established an in vitro model of bovine serum albumin (BSA) injury. RNAi was used to inhibit the expression of megalin, TGFβRII, and Fut8. Western blotting, immunostaining, ELISA, lectin blotting, and fluorescence-activated cell sorting were used to identify BSA-induced endocytic and non-endocytic damage in HK-2 cells. Fut8 is a core fucosylation-related gene, which is significantly increased in HK-2 cells following an incubation with BSA. Fut8 siRNA significantly reduced the core fucosylation of megalin and TGFβRII and also inhibited the activation of the TGFβ/TGFβRII/Smad2/3 signaling pathway. Furthermore, Fut8 siRNA could reduce monocyte chemotactic protein-1, reactive oxygen species, and apoptosis, as well as significantly decrease the fibronectin and collagen I levels in BSA-overloaded HK-2 cells. Core fucosylation inhibition was more effective than inhibiting either megalin or TGFβRII for the prevention of albumin-induced injury to PTECs. Our findings indicate that post-translational core fucosylation is essential for the albumin-induced injury to PTECs. Thus, the inhibition of core fucosylation could effectively alleviate albumin-induced endocytic and non-endocytic injury to PTECs. Our study provides a potential therapeutic target for albuminuria-induced injury.

Transforming growth factor β type II receptor as a marker in diffuse large B cell lymphoma

The objective of this study was to investigate the expression and significance of the transforming growth factor β type II receptor (TGFβRII) in diffuse large B cell lymphoma. All patients were enrolled at the First Affiliated Hospital of Liaoning Medical University between 2001 and 2007. The median follow-up period was 53.3 months. Of the 338 patients studied, 131 (38.76 %) had TGFβRII positive expression on immunohistochemistry. The 5 year survival rate was significantly higher in patients with TGFβRII expression than in those without TGFβRII expression (40.3 vs. 31.6 %, P = 0.041). Multivariate analysis identified TGFβRII expression as an independent predictive parameter for survival, in addition to lactate dehydrogenase, clinical stage, and histologic subtype. TGFβRII expression may be considered a new prognostic factor of diffuse large B cell lymphoma.

Divergence(s) in nodal signaling between aggressive melanoma and embryonic stem cells

The significant role of the embryonic morphogen Nodal in maintaining the pluripotency of embryonic stem cells is well documented. Interestingly, the recent discovery of Nodal's re-expression in several aggressive and metastatic cancers has highlighted its critical role in self renewal and maintenance of the stem cell-like characteristics of tumor cells, such as melanoma. However, the key TGFβ/Nodal signaling component(s) governing Nodal's effects in metastatic melanoma remain mostly unknown. By employing receptor profiling at the mRNA and protein level(s), we made the novel discovery that embryonic stem cells and metastatic melanoma cells share a similar repertoire of Type I serine/threonine kinase receptors, but diverge in their Type II receptor expression. Ligand:receptor crosslinking and native gel binding assays indicate that metastatic melanoma cells employ the heterodimeric TGFβ receptor I/TGFβ receptor II (TGFβRI/TGFβRII) for signal transduction, whereas embryonic stem cells use the Activin receptors I and II (ACTRI/ACTRII). This unexpected receptor usage by tumor cells was tested by: neutralizing antibody to block its function; and transfecting the dominant negative receptor to compete with the endogenous receptor for ligand binding. Furthermore, a direct biological role for TGFβRII was found to underlie vasculogenic mimicry (VM), an endothelial phenotype contributing to vascular perfusion and associated with the functional plasticity of aggressive melanoma. Collectively, these findings reveal the divergence in Nodal signaling between embryonic stem cells and metastatic melanoma that can impact new therapeutic strategies targeting the re-emergence of embryonic pathways.

miR-211 promotes the progression of head and neck carcinomas by targeting TGFβRII

miR-211 up-regulation and transforming growth factor-β type II receptor (TGFβRII) down-regulation are associated with poor prognosis of head and neck squamous cell carcinoma (HNSCC). miR-211 directly targets TGFβRII with the miR-211-TGFβRII-c-Myc axis promoting HNSCC progression. An inverse correlation of miR-211 and TGFβRII expression was found in metastatic HNSCC samples. After 4-nitroquinoline 1-oxide induction, more severe epithelial tumorigenesis was detected on K14-miR-211 transgenic mouse dorsal tongues. Human metastatic lesions and mouse tongue tumors showed increased nuclear c-Myc expression. A novel role for miR-211 in the regulation of TGFβRII and c-Myc during tumorigenesis being revealed should help to develop anti-HNSCC therapies.

Role of caveolin-1 in fibrotic diseases

Fibrosis underlies the pathogenesis of numerous diseases and leads to severe damage of vital body organs and, frequently, to death. Better understanding of the mechanisms resulting in fibrosis is essential for developing appropriate treatment solutions and is therefore of upmost importance. Recent evidence suggests a significant antifibrotic potential of an integral membrane protein, caveolin-1. While caveolin-1 has been widely studied for its role in the regulation of cell signaling and endocytosis, its possible implication in fibrosis remains largely unclear. In this review we survey involvement of caveolin-1 in various cellular processes and highlight different aspects of its antifibrotic activity. We hypothesize that caveolin-1 conveys a homeostatic function in the process of fibrosis by (a) regulating TGF-β1 and its downstream signaling; (b) regulating critical cellular processes involved in tissue repair, such as migration, adhesion and cellular response to mechanical stress; and (c) antagonizing profibrotic processes, such as proliferation. Finally, we consider this homeostatic function of caveolin-1 as a possible novel approach in treatment of fibroproliferative diseases.