Methylation Patterns of DKK1, DKK3 and GSK3β Are Accompanied with Different Expression Levels in Human Astrocytoma

Investigation of iso-propylchaetominine anticancer activity on apoptosis, cell cycle and Wnt signaling pathway in different cancer models

Dysregulation of the Wnt signaling pathway contributes to the development of many cancer types. Natural compounds produced with biotechnological systems have been the focus of research for being a new drug candidate both with unlimited resources and cost-effective production. In this study, it was aimed to reveal the effects of isopropylchaetominine on cytotoxic, cytostatic, apoptotic and Wnt signaling pathways in brain, pancreatic and prostate cancer. The IC50 values of isopropylchaetominine in U-87 MG, PANC1, PC3 and LNCaP cells were calculated as 91.94 μM, 41.68 μM, 54.54 μM and 7.86 μM in 72nd h, respectively. The metabolite arrests the cell cycle in G0/G1 phase in each cancer cells. Iso-propylchaetominine induced a 4.3-fold and 1.9-fold increase in apoptosis in PC3 and PANC1 cells, respectively. The toxicity of isopropylchaetominine in healthy fibroblast cells was assessed using the annexin V method, and no significant apoptotic activity was observed between the groups treated with the active substance and untreated. In U-87 MG, PANC1, PC3, and LNCaP cells under treatment with isopropylchaetominin, the expression levels of DKK3, TLE1, AES, DKK1, FRZB, DAB2, AXIN1/2, PPARD, SFRP4, APC and SOX17 tumor suppressor genes increased significantly. Decreases in expression of Wnt1, Wnt2, Wnt3, Wnt4, Wnt5, Wnt6, Wnt10, Wnt11, FRZ2, FRZ3, FRZ7, TCF7L1, BCL9, PYGO, CCND2, c-MYC, WISP1 and CTNNB1 oncogenic genes were detected. All these result shows that isopropylchaetominine can present promising new treatment strategy in different cancer types.

Cellular signaling in glioblastoma: A molecular and clinical perspective

Glioblastoma multiforme (GBM) is the most aggressive brain tumor with an average life expectancy of less than 15 months. Such high patient mortality in GBM is pertaining to the presence of clinical and molecular heterogeneity attributed to various genetic and epigenetic alterations. Such alterations in critically important signaling pathways are attributed to aberrant gene signaling. Different subclasses of GBM show predominance of different genetic alterations and therefore, understanding the complex signaling pathways and their key molecular components in different subclasses of GBM is extremely important with respect to clinical management. In this book chapter, we summarize the common and important signaling pathways that play a significant role in different subclasses and discuss their therapeutic targeting approaches in terms of preclinical studies and clinical trials.

Wnt Signaling Inhibitors and Their Promising Role in Tumor Treatment

In a continuous search for the improvement of antitumor therapies, the inhibition of the Wnt signaling pathway has been recognized as a promising target. The altered functioning of the Wnt signaling in human tumors points to the strategy of the inhibition of its activity that would impact the clinical outcomes and survival of patients. Because the Wnt pathway is often mutated or epigenetically altered in tumors, which promotes its activation, inhibitors of Wnt signaling are being intensively investigated. It has been shown that knocking down specific components of the Wnt pathway has inhibitory effects on tumor growth in vivo and in vitro. Thus, similar effects are expected from the application of Wnt inhibitors. In the last decades, molecules acting as inhibitors on the pathway’s specific molecular levels have been identified and characterized. This review will discuss the inhibitors of the canonical Wnt pathway, summarize knowledge on their effectiveness as therapeutics, and debate their side effects. The role of the components frequently mutated in various tumors that are principal targets for Wnt inhibitors is also going to be brought to the reader’s attention. Some of the molecules identified as Wnt pathway inhibitors have reached early stages of clinical trials, and some have only just been discovered. All things considered, inhibition of the Wnt signaling pathway shows potential for the development of future therapies.

High CBX8 Expression Leads to Poor Prognosis in Laryngeal Squamous Cell Carcinoma by Inducing EMT by Activating the Wnt/β-Catenin Signaling Pathway

Background

In this study, we detected the expression of chromobox protein homolog 8 (CBX8) in laryngeal squamous cell carcinoma (LSCC) and its influence on the occurrence and progression of LSCC.

Methods

Pancancer analysis of CBX8 was analyzed by TCGA database and its expression in LSCC.The expression of CBX8 in 30 pairs of LSCC and adjacent tissues was analyzed by quantitative real-time PCR(qRT-PCR)and immunohistochemical assays, and its association with the prognosis and clinicopathological features of LSCC was further evaluated. A CBX8 knockdown model was constructed in AMC-HN-8 and Hep2 cell lines. The effects of CBX8 on LSCC cell proliferation, migration, invasion and apoptosis were detected by CCK8,EdU,wound healing, Transwell and flow cytometry assays. Levels of apoptosis-related protein, WNT/β-catenin signaling pathway and epithelial to mesenchymal transition (EMT) proteins, including Bax, Bcl2, β-catenin, DKK1, GSK3β, N-cadherin, E-cadherin and Snail1, in LSCC cells were detected by Western blotting.

Results

CBX8 was overexpressed in LSCC. High expression of CBX8 in LSCC patients led to shorter overall survival and correlated with tumor stage and lymphatic metastasis. After CBX8 knockdown, the proliferation of AMC-HN-8 and Hep2 cells slowed, and the number of EdU-positive cells decreased. Wound healing slowed down, and the number of Transwell invading cells decreased. The percentage of apoptotic cells increased. The expression levels of Bcl2, β-catenin, N-cadherin and Snail11 proteins were significantly reduced in the CBX8 knockdown cells, while Bax, DKK1, GSK3β and E-cadherin significantly increased with their corresponding controls.

Conclusion

CBX8 is highly expressed in LSCC and induces the EMT process by activating the Wnt/β-catenin signaling pathway to promote LSCC cell proliferation and migration and inhibit apoptosis, resulting in poor prognosis.