PPP3CB contributes to poor prognosis through activating nuclear factor of activated T-cells signaling in neuroblastoma

Significant role of PPP3CB in malignant gliomas development, prognosis and potential therapeutic application-a study based on comprehensive bioinformatics, cell experiments and immunohistochemistry analyses

Introduction

Malignant gliomas are the most prevalent and fatal types of primary malignant brain tumors with poor prognosis. Protein phosphatase 3 catalytic subunit beta (PPP3CB) is a pivotal constituent of the Ca2+/calmodulin-dependent serine/threonine protein phosphatases and widely expressed in brain. We aimed at identifying whether PPP3CB has potential in being a novel biomarker of malignant gliomas, bringing new insights to clinical management and therapy.

Methods

Transcriptomes and clinical data of Glioblastoma (GBM) and low-grade glioma (LGG) samples were downloaded from TCGA and CGGA. We first explored the expressional and survival features of tumor tissues. Then, PPP3CB-associated genes were identified and their functional pathways were explored through GSEA analyses. Western blotting was conducted to modify PPP3CB expression. Samples of glioma patients and healthy controls were collected and immunohistochemistry (IHC) staining was performed to detect protein level. Further, we carried out an immune infiltration analysis, explored the correlation between PPP3CB and immune checkpoint genes, as well as to assessed the tumor mutation burden (TMB) and tumor microenvironment score (TMEscore) of PPP3CB.

Results

PPP3CB expression in malignant glioma tissues was significantly downregulated and was considered an independent prognostic factor. Several functional pathways were observed through functional pathway analyses. PPP3CB's expression was strongly related to the infiltration of various immune cells and expression of key immune checkpoint genes. PPP3CB expression in high-grade gliomas was significantly lower, affecting glioma cells' proliferation and apoptosis in vitro.

Conclusion

PPP3CB was a potential biomarker for the diagnosis and prognosis of malignant gliomas.

Apoptosis-related genes-based prognostic signature for osteosarcoma

Osteosarcoma (OS) is a common malignant primary tumor of skeleton, especially in children and adolescents, characterized by high lung metastasis rate. Apoptosis has been studied in various tumors, while the prognostic role of apoptosis-related genes in OS has been seldom studied. Three OS related datasets were downloaded from Gene Expression Omnibus (GEO) database. Univariate Cox and LASSO Cox regression analysis identified optimal genes, which were used for building prognostic Risk score. Subsequent multivariate Cox regression analysis and Kaplan-Meier survival analysis determined the independent prognostic factors for OS. The immune cell infiltration was analyzed in CIBERSORT. Basing on 680 apoptosis-related genes, the OS patients could be divided into 2 clusters with significantly different overall survival. Among which, 6 optimal genes were identified to construct Risk score. In both training set (GSE21257) and validation set (meta-GEO dataset), high risk OS patients had significantly worse overall survival compared with the low risk patients. Besides, high Risk score was an independent poor prognostic factor for OS with various ages or genders. Three immune cells were differentially infiltrated between high and low risk OS patients. In conclusion, a six-gene (TERT, TRAP1, DNM1L, BAG5, PLEKHF1 and PPP3CB) based prognostic Risk score signature is probably conducive to distinguish different prognosis of OS patients.

Diarylpentanoid (1,5-bis(4-hydroxy-3-methoxyphenyl)-1,4-pentadiene-3-one) (MS13) Exhibits Anti-proliferative, Apoptosis Induction and Anti-migration Properties on Androgen-independent Human Prostate Cancer by Targeting Cell Cycle-Apoptosis and PI3K Signalling Pathways

Diarylpentanoids exhibit a high degree of anti-cancer activity and stability in vitro over curcumin in prostate cancer cells. Hence, this study aims to investigate the effects of a diarylpentanoid, 1,5-bis(4-hydroxy-3-methoxyphenyl)-1,4-pentadiene-3-one (MS13) on cytotoxicity, anti-proliferative, apoptosis-inducing, anti-migration properties, and the underlying molecular mechanisms on treated androgen-independent prostate cancer cells, DU 145 and PC-3. A cell viability assay has shown greater cytotoxicity effects of MS13-treated DU 145 cells (EC₅₀ 7.57 ± 0.2 µM) and PC-3 cells (EC₅₀ 7.80 ± 0.7 µM) compared to curcumin (EC₅₀: DU 145; 34.25 ± 2.7 µM and PC-3; 27.77 ± 6.4 µM). In addition, MS13 exhibited significant anti-proliferative activity against AIPC cells compared to curcumin in a dose- and time-dependent manner. Morphological observation, increased caspase-3 activity, and reduced Bcl-2 protein levels in these cells indicated that MS13 induces apoptosis in a time- and dose-dependent. Moreover, MS13 effectively inhibited the migration of DU 145 and PC-3 cells. Our results suggest that cell cycle-apoptosis and PI3K pathways were the topmost significant pathways impacted by MS13 activity. Our findings suggest that MS13 may demonstrate the anti-cancer activity by modulating DEGs associated with the cell cycle-apoptosis and PI3K pathways, thus inhibiting cell proliferation and cell migration as well as inducing apoptosis in AIPC cells.

Isoform-Selective NFAT Inhibitor: Potential Usefulness and Development

Nuclear factor of activated T cells (NFAT), which is the pharmacological target of immunosuppressants cyclosporine and tacrolimus, has been shown to play an important role not only in T cells (immune system), from which their name is derived, but also in many biological events. Therefore, functional and/or structural abnormalities of NFAT are linked to the pathogenesis of diseases in various organs. The NFAT protein family consists of five isoforms, and each isoform performs diverse functions and has unique expression patterns in the target tissues. This diversity has made it difficult to obtain ideal pharmacological output for immunosuppressants that inhibit the activity of almost all NFAT family members, causing serious and wide-ranging side effects. Moreover, it remains unclear whether isoform-selective NFAT regulation can be achieved by targeting the structural differences among NFAT isoforms and whether this strategy can lead to the development of better drugs than the existing ones. This review summarizes the role of the NFAT family members in biological events, including the development of various diseases, as well as the usefulness of and problems associated with NFAT-targeting therapies, including those dependent on current immunosuppressants. Finally, we propose a novel therapeutic strategy based on the molecular mechanisms that enable selective regulation of specific NFAT isoforms.

TRPM8 facilitates proliferation and immune evasion of esophageal cancer cells

Esophageal cancer is seen with increasing incidence, but the underlying mechanism of esophageal cancer is still unknown. Transient receptor potential melastatin (TRPM) is non-selective cation channels. It has been verified that TRPM channels play crucial roles in development and progression of multiple tumors. Increasing studies have shown that TRPM8, a member of TRPM channels, promotes growth of tumors. However, it is still unclear whether TRPM8 has biological effect on esophageal cancer. In the current work, we found that TRPM8 was overexpressed in esophageal cancer samples and cell lines. Further investigation revealed that TRPM8 promoted proliferation of esophageal cancer cells. Next, the co-incubation assay including EC109 cells and CD8⁺ T cells revealed that TRPM8 overexpression and TRPM8 agonist reduced the cytotoxic effect of CD8⁺ T cell on esophageal cancer cells. Finally, we explored the mechanism and found that calcineurin-nuclear factor of activated T cells 3 (NFATc3) pathway contributed to the expression of programmed death ligand 1 (PD-L1) induced by TRPM8 overexpression and TRPM8 agonist, which might lead to immune evasion of esophageal cancer cells. These findings uncovered the crucial role of TRPM8 in the pathogenesis of esophageal cancer.

PPP3CB Inhibits Migration of G401 Cells via Regulating Epithelial-to-Mesenchymal Transition and Promotes G401 Cells Growth

PPP3CB belongs to the phosphoprotein phosphatases (PPPs) group. Although the majority of the PPP family play important roles in the epithelial-to-mesenchymal transition (EMT) of tumor cells, little is known about the function of PPP3CB in the EMT process. Here, we found PPP3CB had high expression in kidney mesenchymal-like cells compared with kidney epithelial-like cells. Knock-down of PPP3CB downregulated epithelial marker E-cadherin and upregulated mesenchymal marker Vimentin, promoting the transition of cell states from epithelial to mesenchymal and reorganizing the actin cytoskeleton which contributed to cell migration. Conversely, overexpression of PPP3CB reversed EMT and inhibited migration of tumor cells. Besides, in vitro and in vivo experiments indicated that the loss of PPP3CB suppressed the tumor growth. However, the deletion of the phosphatase domain of PPP3CB showed no effect on the expression of E-cadherin, migration, and G401 cell proliferation. Together, we demonstrate that PPP3CB inhibits G401 cell migration through regulating EMT and promotes cell proliferation, which are both associated with the phosphatase activity of PPP3CB.