Fas signaling induces stemness properties in colorectal cancer by regulation of Bmi1

Cancer stem cells: advances in knowledge and implications for cancer therapy

Cancer stem cells (CSCs), a small subset of cells in tumors that are characterized by self-renewal and continuous proliferation, lead to tumorigenesis, metastasis, and maintain tumor heterogeneity. Cancer continues to be a significant global disease burden. In the past, surgery, radiotherapy, and chemotherapy were the main cancer treatments. The technology of cancer treatments continues to develop and advance, and the emergence of targeted therapy, and immunotherapy provides more options for patients to a certain extent. However, the limitations of efficacy and treatment resistance are still inevitable. Our review begins with a brief introduction of the historical discoveries, original hypotheses, and pathways that regulate CSCs, such as WNT/β-Catenin, hedgehog, Notch, NF-κB, JAK/STAT, TGF-β, PI3K/AKT, PPAR pathway, and their crosstalk. We focus on the role of CSCs in various therapeutic outcomes and resistance, including how the treatments affect the content of CSCs and the alteration of related molecules, CSCs-mediated therapeutic resistance, and the clinical value of targeting CSCs in patients with refractory, progressed or advanced tumors. In summary, CSCs affect therapeutic efficacy, and the treatment method of targeting CSCs is still difficult to determine. Clarifying regulatory mechanisms and targeting biomarkers of CSCs is currently the mainstream idea.

CD95 promotes stemness of colorectal cancer cells by lncRNA MALAT1

Colorectal cancer (CRC) is the second most fatal cancer. Many studies have shown that cancer stemness contributes to resistance to conventional chemotherapy and poor prognosis. However, the mechanisms involved in maintaining cancer stemness in CRC are still obscure and few clinical drugs were used to target cancer stemness. Previous studies had reported CD95 increases the stemness of cancer cells with long-term stimulation of exogenous agonist CD95 ligand (CD95L). However, the expression of CD95L is relative low in certain human tumor tissues. In this study, we found that CD95 was highly expressed in CRC cells, and in vitro it promoted the tumorsphere formation, chemotherapy resistance and in vivo tumor growth without stimulation of exogenous CD95L. Mechanistically, the bulk and single-cell RNA-sequencing results suggested that CD95 promotes stemness of CRC cells through upregulation of long non-coding RNAs metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1). MALAT1 knockdown inhibited CD95-induced tumorsphere formation and chemotherapy resistance. In summary, our findings reveal that CD95 has the capability to modulate cancer stemness via the action of the lncRNA MALAT1. Targeting CD95 may be a promising strategy to inhibit cancer stemness in CRC.

B-cell-specific Moloney murine leukemia virus integration site 1 knockdown impairs adriamycin resistance of gastric cancer cells

BACKGROUND AND STUDY AIMS

The B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) is associated with the progression of gastric cancer (GC). However, its role in drug resistance of gastric cancer stem cell (GCSC) remains unclear. This study aimed to explore the biological function of BMI-1 in GC cells and its role in drug resistance of GCSCs.

PATIENTS AND METHODS

We assessed BMI-1 expression in the GEPIA database and in our collected samples from patients with GC. We silenced BMI-1 using siRNA to study the cell proliferation and migration of GC cells. We also used Hoechst 33342 staining to verify the effect of adriamycin (ADR) on side population (SP) cells, and measured the effects of BMI-1 on the expression of N-cadherin, E-cadherin, and drug-resistance-related proteins (multidrug resistance mutation 1 and lung resistance-related protein). Finally, we analyzed BMI-1-related proteins uing the STRING and GEPIA databases.

RESULTS

BMI-1 mRNA was upregulated in GC tissues and cell lines, especially in MKN-45 and HGC-27 cells. Silencing BMI-1 reduced the proliferation and migration of GC cells. Knocking down BMI-1 significantly decreased epithelial-mesenchymal transition progression, expression levels of drug-resistant proteins, and the number of SP cells in ADR-treated GC cells. Bioinformatics analysis showed that EZH2, CBX8, CBX4, and SUZ12 were positively correlated with BMI-1 in GC tissues.

CONCLUSION

Our study demonstrates that BMI-1 affects the cellular activity, proliferation, migration, and invasion of GC cells. Silencing the BMI-1 gene significantly reduces the number of SP cells and the expression of drug-resistant proteins in ADR-treated GC cells. We speculate that inhibition of BMI-1 increases the drug resistance of GC cells by affecting GCSCs, and that EZH2, CBX8, CBX4, and SUZ12 may participate in BMI-1-induced enhancement of GCSC-like phenotype and viability.

Wnt/β-catenin signaling pathway-a versatile player in apoptosis and autophagy

The Wnt/β-catenin signaling pathway is a highly conserved pathway that is involved in cell development, proliferation, differentiation, apoptosis and autophagy. Among these processes, apoptosis and autophagy occur physiologically during host defense and the maintenance of intracellular homeostasis. Mounting evidence suggests that the crosstalk between Wnt/β-catenin-regulated apoptosis and autophagy has broad functional significance in various diseases. Herein, we summarize the recent studies in understanding the role of the Wnt/β-catenin signaling pathway in apoptosis and autophagy, and draw the following conclusions: a) For apoptosis, the regulation of Wnt/β-catenin is generally positive. However, a small amount of evidence indicates the presence of a negatively regulated relationship between Wnt/β-catenin and apoptosis; b) Wnt/β-catenin influences the occurrence and development of autophagy by regulating autophagy-related factors, and these factors in turn affect Wnt/β-catenin pathway; c) Wnt/β-catenin always balances the molecular damage caused by the crosstalk between autophagy and apoptosis in a compensatory manner. Understanding the specific role of the Wnt/β-catenin signaling pathway during different stages of autophagy and apoptosis may provide new insights into the progression of related diseases regulated by the Wnt/β-catenin signaling pathway.

GSK3β palmitoylation mediated by ZDHHC4 promotes tumorigenicity of glioblastoma stem cells in temozolomide-resistant glioblastoma through the EZH2-STAT3 axis

Glioblastoma stem cells (GSCs) are a highly tumorigenic cell subgroup of glioblastoma (GBM). Glycogen synthase kinase 3β (GSK3β) is considered a key hub for promoting malignant phenotypes in GBM. However, the functional relationships between GSK3β and GSCs in GBM are unclear. Here, we found that GSK3β was noted as a substrate for ZDHHC4-mediated palmitoylation at the Cys14 residue, which enhanced GBM temozolomide (TMZ) resistance and GSC self-renewal. Clinically, the expression level of ZDHHC4 was upregulated in GBM, which significantly correlated with tumor grade and poor prognosis. The above phenotypes were based on decreasing p-Ser9 and increasing p-Tyr216 by GSK3β palmitoylation, which further activated the enhancer of the zeste homolog 2 (EZH2)-STAT3 pathway. Notably, STAT3 silencing also inhibited ZDHHC4 expression. This study revealed that GSK3β palmitoylation mediated by ZDHHC4 improved the stemness of TMZ-resistant GBM by activating the EZH2-STAT3 signaling axis, providing a new theoretical basis for further understanding the mechanism of TMZ resistance and recurrence after treatment.

Conservation of Epithelial-to-Mesenchymal Transition Process in Neural Crest Cells and Metastatic Cancer

Epithelial to mesenchymal transition (EMT) is a highly conserved cellular process in several species, from worms to humans. EMT plays a fundamental role in early embryogenesis, wound healing, and cancer metastasis. For neural crest cell (NCC) development, EMT typically results in forming a migratory and potent cell population that generates a wide variety of cell and tissue, including cartilage, bone, connective tissue, endocrine cells, neurons, and glia amongst many others. The degree of conservation between the signaling pathways that regulate EMT during development and metastatic cancer (MC) has not been fully established, despite ample studies. This systematic review and meta-analysis dissects the major signaling pathways involved in EMT of NCC development and MC to unravel the similarities and differences. While the FGF, TGFβ/BMP, SHH, and NOTCH pathways have been rigorously investigated in both systems, the EGF, IGF, HIPPO, Factor Receptor Superfamily, and their intracellular signaling cascades need to be the focus of future NCC studies. In general, meta-analyses of the associated signaling pathways show a significant number of overlapping genes (particularly ligands, transcription regulators, and targeted cadherins) involved in each signaling pathway of both systems without stratification by body segments and cancer type. Lack of stratification makes it difficult to meaningfully evaluate the intracellular downstream effectors of each signaling pathway. Finally, pediatric neuroblastoma and melanoma are NCC-derived malignancies, which emphasize the importance of uncovering the EMT events that convert NCC into treatment-resistant malignant cells.

miRNA Clusters with Up-Regulated Expression in Colorectal Cancer

Simple Summary

As miRNAs show the capacity to be used as CRC biomarkers, we analysed experimentally validated data about frequently up-regulated miRNA clusters in CRC tissue. We identified 15 clusters that showed increased expression in CRC: miR-106a/363, miR-106b/93/25, miR-17/92a-1, miR-181a-1/181b-1, miR-181a-2/181b-2, miR-181c/181d, miR-183/96/182, miR-191/425, miR-200c/141, miR-203a/203b, miR-222/221, mir-23a/27a/24-2, mir-29b-1/29a, mir-301b/130b and mir-452/224. Cluster positions in the genome are intronic or intergenic. Most clusters are regulated by several transcription factors, and by long non-coding RNAs. In some cases, co-expression of miRNA with other cluster members or host gene has been proven. miRNA expression patterns in cancer tissue, blood and faeces were compared. The members of the selected clusters target 181 genes. Their functions and corresponding pathways were revealed with the use of Panther analysis. Clusters miR-17/92a-1, miR-106a/363, miR-106b/93/25 and miR-183/96/182 showed the strongest association with metastasis occurrence and poor patient survival, implicating them as the most promising targets of translational research.

Abstract

Colorectal cancer (CRC) is one of the most common malignancies in Europe and North America. Early diagnosis is a key feature of efficient CRC treatment. As miRNAs can be used as CRC biomarkers, the aim of the present study was to analyse experimentally validated data on frequently up-regulated miRNA clusters in CRC tissue and investigate their members with respect to clinicopathological characteristics of patients. Based on available data, 15 up-regulated clusters, miR-106a/363, miR-106b/93/25, miR-17/92a-1, miR-181a-1/181b-1, miR-181a-2/181b-2, miR-181c/181d, miR-183/96/182, miR-191/425, miR-200c/141, miR-203a/203b, miR-222/221, mir-23a/27a/24-2, mir-29b-1/29a, mir-301b/130b and mir-452/224, were selected. The positions of such clusters in the genome can be intronic or intergenic. Most clusters are regulated by several transcription factors, and miRNAs are also sponged by specific long non-coding RNAs. In some cases, co-expression of miRNA with other cluster members or host gene has been proven. miRNA expression patterns in cancer tissue, blood and faeces were compared. Based on experimental evidence, 181 target genes of selected clusters were identified. Panther analysis was used to reveal the functions of the target genes and their corresponding pathways. Clusters miR-17/92a-1, miR-106a/363, miR-106b/93/25 and miR-183/96/182 showed the strongest association with metastasis occurrence and poor patient survival, implicating them as the most promising targets of translational research.

Assessment of clinicopathological and prognostic relevance of BMI-1 in patients with colorectal cancer: A meta-analysis

B-cell-specific Moloney leukemia virus insertion site 1 (BMI-1) is one of the stemness markers. The prognostic and clinicopathological effects of BMI-1 expression in colorectal cancer (CRC) have been in dispute with different studies. Eligible studies were retrieved from international databases up to December 2019. Studies with a relationship between the clinicopathological and prognostic value of CRC patients with BMI-1 expression were selected. The correlations in the random-effect model were evaluated using the hazard ratios, odds ratio, and 95% confidence intervals (CIs). A total of nine studies comprising Asian cases (seven studies) and European cases (two studies) covering 1,294 samples of CRC were included for this meta-analysis. The analysis suggested that in Asian cases, increased expression of BMI-1 was associated with poor overall survival (OS) and death-free survival, whereas in European populations, high expression of BMI-1 was associated with better OS. Also, overexpression of BMI-1 in the Asian population was associated with the tumor size, distant metastasis, and patient's gender and age. Results suggested that high expression of BMI-1 can be involved in the progression and invasion of CRC, and so its inhibitor-based therapies could be used to prevent the progression of CRC.

Inflammatory Serum Biomarkers in Colorectal Cancer in Kazakhstan Population

Colorectal cancer is a type of oncopathology widespread in Kazakhstan. The genetic component, as well as the possible etiopathogenetic mechanisms, is widely studied. One of the most promising areas is the study of diagnostic and prognostic possibilities of inflammatory biomarkers in patients with different degrees of tumor differentiation. The following biomarkers were included in the study panel: stem cell factor (SCF), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF2), interleukin 6 (IL6), interleukin 8 (IL8), macrophage migration inhibitory factor (MIF), soluble Fas (SFAS), soluble Fas ligand (sFASL), transforming growth factor β (TGF), tumor necrosis factor (TNF), TNF-related apoptosis-inducing ligand (TRAIL), and programmed death ligand 1 (PD-L1). The data of our study show that most of the basic proinflammatory cytokines are involved in the systemic process and their levels do not depend on the level of tissue differentiation. Serum PD-L1 has shown itself to be a promising marker for tumor growth, which depends on the degree of differentiation.

The Construction and Analysis of ceRNA Network and Patterns of Immune Infiltration in Colon Adenocarcinoma Metastasis

BACKGROUND

Colon adenocarcinoma (COAD) is a malignant and lethal tumor in digestive system and distance metastasis lead to poor prognosis. The metastasis-specific ceRNAs (competitive endogenous RNAs) and tumor-infiltrating immune cells might associate with tumor prognosis and distance metastasis. Nonetheless, few studies have concentrated on ceRNAs and Immune cells in COAD.

METHODS

The gene expression profile and clinical information of COAD were downloaded from TCGA and divided into two groups: primary tumors with or without distance metastasis. We applied comprehensive bioinformatics methods to analyze differential expression genes (DEGs) related to metastasis and establish the ceRNA networks. The Cox analysis and Lasso regression were utilized to screen the pivotal genes and prevent overfitting. Based on them, the prognosis prediction nomograms were established. The cell type identification by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm was then applied to screen significant tumor immune-infiltrating cells associated with COAD metastasis and established another prognosis prediction model. Ultimately, co-expression analysis was applied to explore the relationship between key genes in ceRNA networks and significant immune cells. Multiple databases and preliminary clinical specimen validation were used to test the expressions of key biomarkers at the cellular and tissue levels.

RESULTS

We explored 1 significantly differentially expressed lncRNA, 1 significantly differentially expressed miRNA, 8 survival-related immune-infiltrating cells, 5 immune cells associated with distance metastasis. Besides, 3 pairs of important biomarkers associated with COAD metastasis were also identified: T cells follicular helper and hsa-miR-125b-5p (R = -0.200, P < 0.001), Macrophages M0 and hsa-miR-125b-5p (R = 0.170, P < 0.001) and Macrophages M0 and FAS (R = -0.370, P < 0.001). Multidimensional validation and preliminary clinical specimen validation also supported the results.

CONCLUSION

In this research, we found some significant ceRNAs (FAS and hsa-miR-125b-5p) and tumor-infiltrating immune cells (T cells follicular helper and Macrophages M0) might related to distance metastasis and prognosis of COAD. The nomograms could assist scientific and medical researchers in clinical management.

Regulation of cancer stem cell properties, angiogenesis, and vasculogenic mimicry by miR-450a-5p/SOX2 axis in colorectal cancer

Growing evidence indicates that a small number of cancer cells express stem cell markers and possess stem cell-like properties that promote malignant progression. Sex-determining region Y-box2 (SOX2) is a stem cell transcription factor essential for maintaining the properties of cancer stem cell (CSC). As CSC properties have been associated with angiogenesis and vasculogenic mimicry (VM), we aimed to comprehensively investigate whether SOX2 regulates CSC properties, angiogenesis, and VM in colorectal carcinoma (CRC) and its potential mechanism in this study. For this study, sphere formation assay, flow cytometry, cell survival analysis, tube formation, 3D culture, immunoblot, mouse model, and luciferase reporter assay were performed in vivo and in vitro. Expressions of SOX2 and miR-450a-5p in CRC tissue samples were examined through immunohistochemistry. First, the expression of SOX2 was not only associated with poor differentiation and prognosis but also promoted angiogenesis and VM. Knockdown of SOX2 ceased stemness properties, angiogenesis, and VM, along with decreased expression of CD133, CD31, and VE-cadherin as observed in functional experiments. Downregulation of SOX2 was found to inhibit tumorigenesis in vivo. Second, miR-450a-5p suppressed the expression of SOX2 by targeting its 3’UTR region directly and hence restrained SOX2-induced CSC properties, angiogenesis, and VM. Moreover, SOX2 overexpression preserved the miR-450a-5p-induced inhibition of CRC properties, angiogenesis, and VM. Finally, clinical samples exhibited a negative correlation between miR-450a-5p and SOX2. Patients with higher SOX2 and lower miR-450a-5p expressions had a poorer prognosis than patients with inverse expressions. Conclusively, we elucidated a unique mechanism of miR-450a-5p-SOX2 axis in the regulation of stemness, angiogenesis, and VM, which may act as a potential therapeutic practice in CRC.

microRNA biomarkers in colorectal cancer liver metastasis

Liver metastasis is a primary factor of prognosis and long-term survival for patients diagnosed with colorectal cancer (CRC). Colorectal cancer liver metastasis (CRCLM), is a complex biological process involving multiple factors and steps, and its mechanisms are yet to be discovered. In recent years, small noncoding RNAs, especially microRNAs (miRNAs) have been proven to play an important role in tumorigenesis, progression and metastasis in a variety of cancers, including CRC. Increasing evidence suggests that miRNAs, including those from exosomes secreted by tumor cells in circulation, could be used as promising biomarkers in early cancer detection, treatment, and prognosis. In this review, we focus on the functional roles and clinical applications of miRNAs, especially those from circulating exosomes secreted by tumor cells related to CRCLM.

A web platform for the network analysis of high-throughput data in melanoma and its use to investigate mechanisms of resistance to anti-PD1 immunotherapy

Cellular phenotypes are established and controlled by complex and precisely orchestrated molecular networks. In cancer, mutations and dysregulations of multiple molecular factors perturb the regulation of these networks and lead to malignant transformation. High-throughput technologies are a valuable source of information to establish the complex molecular relationships behind the emergence of malignancy, but full exploitation of this massive amount of data requires bioinformatics tools that rely on network-based analyses. In this report we present the Virtual Melanoma Cell, an online tool developed to facilitate the mining and interpretation of high-throughput data on melanoma by biomedical researches. The platform is based on a comprehensive, manually generated and expert-validated regulatory map composed of signaling pathways important in malignant melanoma. The Virtual Melanoma Cell is a tool designed to accept, visualize and analyze user-generated datasets. It is available at: https://www.vcells.net/melanoma. To illustrate the utilization of the web platform and the regulatory map, we have analyzed a large publicly available dataset accounting for anti-PD1 immunotherapy treatment of malignant melanoma patients.

Quantitative assessment of the relationship between Fas/FasL genes polymorphisms and head and neck cancer risk

BACKGROUND

Molecular epidemiological studies have demonstrated a closer association between Fas/FasL polymorphisms and head and neck cancer (HNC) risk, and the results of these published studies were inconsistent. We therefore performed this meta-analysis to explore the associations between Fas/FasL polymorphisms and HNC risk.

METHODS

Four online databases (PubMed, Embase, CNKI, and Wanfang) were searched. Odds ratios (ORs) with 95% confidence interval (95% CIs) were calculated to assess the association between Fas -670A>G, Fas -1377G>A, and FasL -844C>T polymorphisms and HNC risk. In addition, heterogeneity, accumulative/sensitivity analysis, and publication bias were conducted to check the statistical power.

RESULTS

Overall, 9 related publications (20 independent case-control studies) involving 3179 patients and 4217 controls were identified. Significant association of protective effects was observed between FasL -844C>T polymorphism and HNC risk in codominant and dominant model models (CT vs CC: OR = 0.89, 95% CI = 0.79-1.00, P = .05, I = 38.3%, CT+TT vs CC: OR = 0.88, 95% CI = 0.79-0.98, P = .02, I = 35.8%). Furthermore, the similar protective effects were observed the subgroup analysis of in Asian population and population-based controls group.

CONCLUSION

Our meta-analysis indicated that FasL -844C>T polymorphism plays a protective role against HNC development, but the Fas -670A>G and Fas -1377G>A polymorphisms maybe not associated with HNC risk.