Reciprocal impacts of telomerase activity and ADRN/MES differentiation state in neuroblastoma tumor biology

Telomere maintenance and tumor cell differentiation have been separately implicated in neuroblastoma malignancy. Their mechanistic connection is unclear. We analyzed neuroblastoma cell lines and morphologic subclones representing the adrenergic (ADRN) and mesenchymal (MES) differentiation states and uncovered sharp differences in their telomere protein and telomerase activity levels. Pharmacologic conversion of ADRN into MES cells elicited consistent and robust changes in the expression of telomere-related proteins. Conversely, stringent down-regulation of telomerase activity triggers the differentiation of ADRN into MES cells, which was reversible upon telomerase up-regulation. Interestingly, the MES differentiation state is associated with elevated levels of innate immunity factors, including key components of the DNA-sensing pathway. Accordingly, MES but not ADRN cells can mount a robust response to viral infections in vitro. A gene expression signature based on telomere and cell lineage-related factors can cluster neuroblastoma tumor samples into predominantly ADRN or MES-like groups, with distinct clinical outcomes. Our findings establish a strong mechanistic connection between telomere and differentiation and suggest that manipulating telomeres may suppress malignancy not only by limiting the tumor growth potential but also by inducing tumor cell differentiation and altering its immunogenicity.

Research Progress on the Antitumor Mechanism of Compound Kushen Injection

Compound Kushen Injection (CKI), as a clinical traditional Chinese medicine preparation, has prominent antitumor effect but with several side effects. A large number of studies have shown that CKI plays an antitumor role by regulating tumor cell proliferation, inducing tumor cell differentiation and apoptosis, inhibiting tumor cell invasion and metastasis, reducing tumor angiogenesis, regulating the immunity, and so on. Clinically, CKI is widely used to treat various tumors, where it is often combined with surgery, chemotherapy, radiotherapy, targeted therapy, and other antitumor treatments. This article reviews the antitumor mechanism of CKI and the progress of its clinical application in order to provide a theoretical basis for further clinical application.

Reciprocal impacts of telomerase activity and tumor cell differentiation in neuroblastoma tumor biology

Telomere maintenance and tumor cell differentiation have been separately implicated in neuroblastoma malignancy. Their mechanistic connection is unclear. We analyzed neuroblastoma cell lines and morphologic subclones representing the adrenergic (ADRN) and mesenchymal (MES) differentiation states and uncovered sharp differences in their telomere protein and telomerase activity levels. Pharmacologic conversion of ADRN into MES cells elicited consistent and robust changes in the expression of telomere-related proteins. Conversely, stringent down-regulation of telomerase activity triggers the differentiation of ADRN into MES cells, which was reversible upon telomerase up-regulation. Interestingly, the MES differentiation state is associated with elevated levels of innate immunity factors, including key components of the DNA-sensing pathway. Accordingly, MES but not ADRN cells can mount a robust response to viral infections in vitro. A gene expression signature based on telomere and cell lineage-related factors can cluster neuroblastoma tumor samples into predominantly ADRN or MES-like groups, with distinct clinical outcomes. Our findings establish a novel mechanistic connection between telomere and differentiation and suggest that manipulating telomeres may suppress malignancy not only by limiting the tumor growth potential but also by inducing tumor cell differentiation and altering its immunogenicity.

DNMT family induced down-regulation of NDRG1 via DNA methylation and clinicopathological significance in gastric cancer

BackgroundAberrant DNA methylation of tumor suppressor genes is a common event in the development and progression of gastric cancer(GC). Our previous study showed NDRG1, which could suppress cell invasion and migration, was frequently down-regulated by DNA methylation of its promoter in GC.Purpose and MethodsTo analyze the relationship between the expression and DNA methylation of NDRG1 and DNA methyltransferase (DNMT) family. We performed a comprehensive comparison analysis using 407 patients including sequencing analysis data of GC from TCGA.ResultsNDRG1 was negatively correlative to DNMT1 (p =0.03), DNMT3A(p =0.01), DNMT3B(p =0.88), respectively. Whereas, the DNA methylation of NDRG1 was positively correlative to DNMT family(DNMT1 p<0.01, DNMT3A p<0.001, DNMT3B p=0.57, respectively). NDRG1 expression was significantly inverse correlated with invasion depth (p =0.023), and DNMT1 was significantly positive correlated with the degree of tumor cell differentiation (p =0.049). DNMT3B was significantly correlated with tumor cell differentiation (p =0.030). However, there was no association between the expression of DNMT3A and clinicopathological features. The univariate analysis showed that NDRG1and DNMTs had no association with prognosis of GC patients. But, multivariate analysis showed DNMT1 was significantly correlated with prognosis of GC patients.ConclusionThese data suggest that down-regulation of NDRG1 in gastric cancer is due to DNA methylation of NDRG1 gene promoter via DNMT family. The demethylating agent maybe a potential target drug for GC patients.

Correlation Between Tumor Cell Differentiation and CEA Levels in Patients with Adenocarcinoma of the Rectum

Adenocarcinoma of the rectum is the most common colorectal cancer in Indonesia. This cancer has the highest recurrence after curative surgical therapy with or without adjuvant therapy. With the advancing modern histopathology and molecular biology, the prognosis after therapy can be predicted through surveillance using tumor cell differentiation and carcinoembryonic antigen (CEA). The aim of this study was to analyze the correlation between tumor cell differentiation and serum CEA level in patients with adenocarcinoma of the rectum in Dr. Hasan Sadikin General Hospital Bandung, Indonesia. This was a retrospective observational analytic study conducted from January 2018- January 2019. There were 36 patients involved in this study consisting of 3 patients (8.3%) diagnosed with Stage II, 10 patients (27.7%) with Stage IIIA, 20 patients (55.5%) with stage IIIB, and 3 patients (8.3%) with stage IIIC. On histopathological examination, it was demonstrated that19 patients (52.8%) were well-differentiated, 15 patients (41.7%) were moderately differentiated, and 2 patients (5.6%) were poorly differentiated. The mean CEA level (CI 95%) for well-differentiated patients before surgery was 138.18 (15.99-260.38) ng/ml while the same level for the moderately differentiated patients was 64.34 (34.34-163.02) ng/ml. The mean CEA level for poorly differentiated patients was 1.55 (6.71-9.81) ng / ml. The result of the Kruskal Wallis test showed a p-value of 0.004. There is a strong correlation between the level of tumor cell differentiation and CEA level.

Phosphorylation of OCT4 Serine 236 Inhibits Germ Cell Tumor Growth by Inducing Differentiation

Octamer-binding transcription factor 4 (Oct4) plays an important role in maintaining pluripotency in embryonic stem cells and is closely related to the malignancies of various cancers. Although posttranslational modifications of Oct4 have been widely studied, most of these have not yet been fully characterized, especially in cancer. In this study, we investigated the role of phosphorylation of serine 236 of OCT4 [OCT4 (S236)] in human germ cell tumors (GCTs). OCT4 was phosphorylated at S236 in a cell cycle-dependent manner in a patient sample and GCT cell lines. The substitution of endogenous OCT4 by a mimic of phosphorylated OCT4 with a serine-to-aspartate mutation at S236 (S236D) resulted in tumor cell differentiation, growth retardation, and inhibition of tumor sphere formation. GCT cells expressing OCT4 S236D instead of endogenous OCT4 were similar to cells with OCT4 depletion at the mRNA transcript level as well as in the phenotype. OCT4 S236D also induced tumor cell differentiation and growth retardation in mouse xenograft experiments. Inhibition of protein phosphatase 1 by chemicals or short hairpin RNAs increased phosphorylation at OCT4 (S236) and resulted in the differentiation of GCTs. These results reveal the role of OCT4 (S236) phosphorylation in GCTs and suggest a new strategy for suppressing OCT4 in cancer.