scholarly journals HP1a-mediated heterochromatin formation inhibits high dietary sugar-induced tumor progression

2021 ◽  
Vol 12 (12) ◽  
Author(s):  
Che-Wei Chang ◽  
Yu-Chia Shen ◽  
Shian-Jang Yan

AbstractHigh dietary sugar (HDS) is a modern dietary concern that involves excessive consumption of carbohydrates and added sugars, and increases the risk of metabolic disorders and associated cancers. However, epigenetic mechanisms by which HDS induces tumor progression remain unclear. Here, we investigate the role of heterochromatin, an important yet poorly understood part of the epigenome, in HDS-induced tumor progression of Drosophila Ras/Src and Ras/scrib tumor systems. We found that increased heterochromatin formation with overexpression of heterochromatin protein 1a (HP1a), specifically in tumor cells, not only decreases HDS-induced tumor growth/burden but also drastically improves survival of Drosophila with HDS and Ras/Src or Ras/scrib tumors. Moreover, HDS reduces heterochromatin levels in tumor cells. Mechanistically, we demonstrated that increased heterochromatin formation decreases wingless (wg) and Hippo (Hpo) signaling, thereby promoting apoptosis, via inhibition of Yorkie (Yki) nuclear accumulation and upregulation of apoptotic genes, and reduces DNA damage in tumor cells under HDS. Taken together, our work identified a novel epigenetic mechanism by which HP1a-mediated heterochromatin formation suppresses HDS-induced tumor progression likely by decreasing wingless and Hippo signaling, increasing apoptosis, and maintaining genome stability. Our model explains that the molecular, cellular, and organismal aspects of HDS-aggravated tumor progression are dependent on heterochromatin formation, and highlights heterochromatin as a therapeutic target for cancers associated with HDS-induced metabolic disorders.

2021 ◽  
Vol 20 (4) ◽  
pp. 130-145
Author(s):  
E. V. Semina ◽  
N. V. Danilova ◽  
N. A. Oleinikova ◽  
M. A. Agapov ◽  
K. A. Rubina

Background. Type 2 diabetes mellitus, obstructive sleep apnea, osteoarthritis and certain types of cancer are known to correlate with obesity. The mechanisms underlying the link between metabolic disorders and cancer remain obscure, yet assuming a potentially important role of reduced insulin sensitivity, altered glucose metabolism in tumor cells (the so-called Warburg effect), changes in the spectrum of secreted adipokines or interaction with their cognitive receptors as well as changes in steroid sex hormone production.Material and methods. A search for articles published in peer-reviewed journals indexed in pubmed, Wos, scopus and Rsci was carried out. More than 150 articles devoted to the study of the relationship between metabolic disorders and tumor progression were analyzed, of which 69 were included in this review.Results. The main strategy of anticancer therapy is to suppress the proliferation of tumor cells and metastasis. However, one should take into consideration a significant role of additional factors that can enhance side effects of anticancer therapy, ensure the resistance of tumor cells to chemotherapy or change cancer cell metabolic profile. New data recently emerging in the literature indicate an important function of proteins such as t-cadherin and urokinase receptor (upar) and their possible involvement in the regulation of tumor cell metabolism, in particular, sensitivity to insulin and adipose tissue hormones. The review encompasses recent data on the involvement of t-cadherin and upar in the regulation of metabolism and proposes a model explaining the relationship between these proteins and metabolic disorders associated with the processes of carcinogenesis and chemoresistance of cancer cells.Conclusion. Understanding of the factors and mechanisms that support obesity and metabolic disorders is relevant both for the development of cancer preventive measures and optimization of therapeutic strategies for combating cancer.


2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Shuang Cui ◽  
Qiong Wu ◽  
Ming Liu ◽  
Mu Su ◽  
ShiYou Liu ◽  
...  

AbstractSuper-enhancers or stretch enhancers (SEs) consist of large clusters of active transcription enhancers which promote the expression of critical genes that define cell identity during development and disease. However, the role of many super-enhancers in tumor cells remains unclear. This study aims to explore the function and mechanism of a new super-enhancer in various tumor cells. A new super-enhancer that exists in a variety of tumors named EphA2-Super-enhancer (EphA2-SE) was found using multiple databases and further identified. CRISPR/Cas9-mediated deletion of EphA2-SE results in the significant downregulation of its target gene EphA2. Mechanistically, we revealed that the core active region of EphA2-SE comprises E1 component enhancer, which recruits TCF7L2 and FOSL2 transcription factors to drive the expression of EphA2, induce cell proliferation and metastasis. Bioinformatics analysis of RNA-seq data and functional experiments in vitro illustrated that EphA2-SE deletion inhibited cell growth and metastasis by blocking PI3K/AKT and Wnt/β-catenin pathway in HeLa, HCT-116 and MCF-7 cells. Overexpression of EphA2 in EphA2-SE−/− clones rescued the effect of EphA2-SE deletion on proliferation and metastasis. Subsequent xenograft animal model revealed that EphA2-SE deletion suppressed tumor proliferation and survival in vivo. Taken together, these findings demonstrate that EphA2-SE plays an oncogenic role and promotes tumor progression in various tumors by recruiting FOSL2 and TCF7L2 to drive the expression of oncogene EphA2.


Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 180
Author(s):  
Christina Mertens ◽  
Matthias Schnetz ◽  
Claudia Rehwald ◽  
Stephan Grein ◽  
Eiman Elwakeel ◽  
...  

Macrophages supply iron to the breast tumor microenvironment by enforced secretion of lipocalin-2 (Lcn-2)-bound iron as well as the increased expression of the iron exporter ferroportin (FPN). We aimed at identifying the contribution of each pathway in supplying iron for the growing tumor, thereby fostering tumor progression. Analyzing the expression profiles of Lcn-2 and FPN using the spontaneous polyoma-middle-T oncogene (PyMT) breast cancer model as well as mining publicly available TCGA (The Cancer Genome Atlas) and GEO Series(GSE) datasets from the Gene Expression Omnibus database (GEO), we found no association between tumor parameters and Lcn-2 or FPN. However, stromal/macrophage-expression of Lcn-2 correlated with tumor onset, lung metastases, and recurrence, whereas FPN did not. While the total iron amount in wildtype and Lcn-2−/− PyMT tumors showed no difference, we observed that tumor-associated macrophages from Lcn-2−/− compared to wildtype tumors stored more iron. In contrast, Lcn-2−/− tumor cells accumulated less iron than their wildtype counterparts, translating into a low migratory and proliferative capacity of Lcn-2−/− tumor cells in a 3D tumor spheroid model in vitro. Our data suggest a pivotal role of Lcn-2 in tumor iron-management, affecting tumor growth. This study underscores the role of iron for tumor progression and the need for a better understanding of iron-targeted therapy approaches.


2021 ◽  
Vol 22 (4) ◽  
pp. 1918
Author(s):  
Mio Yamaguchi ◽  
Kiyoshi Takagi ◽  
Koki Narita ◽  
Yasuhiro Miki ◽  
Yoshiaki Onodera ◽  
...  

Chemokines secreted from stromal cells have important roles for interactions with carcinoma cells and regulating tumor progression. C-C motif chemokine ligand (CCL) 5 is expressed in various types of stromal cells and associated with tumor progression, interacting with C-C chemokine receptor (CCR) 1, 3 and 5 expressed in tumor cells. However, the expression on CCL5 and its receptors have so far not been well-examined in human breast carcinoma tissues. We therefore immunolocalized CCL5, as well as CCR1, 3 and 5, in 111 human breast carcinoma tissues and correlated them with clinicopathological characteristics. Stromal CCL5 immunoreactivity was significantly correlated with the aggressive phenotype of breast carcinomas. Importantly, this tendency was observed especially in the CCR3-positive group. Furthermore, the risk of recurrence was significantly higher in the patients with breast carcinomas positive for CCL5 and CCR3 but negative for CCR1 and CCR5, as compared with other patients. In summary, the CCL5-CCR3 axis might contribute to a worse prognosis in breast cancer patients, and these findings will contribute to a better understanding of the significance of the CCL5/CCRs axis in breast carcinoma microenvironment.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yu-Ching Teng ◽  
Aishwarya Sundaresan ◽  
Ryan O’Hara ◽  
Vincent U. Gant ◽  
Minhua Li ◽  
...  

AbstractATRX is a tumor suppressor that has been associated with protection from DNA replication stress, purportedly through resolution of difficult-to-replicate G-quadruplex (G4) DNA structures. While several studies demonstrate that loss of ATRX sensitizes cells to chemical stabilizers of G4 structures, the molecular function of ATRX at G4 regions during replication remains unknown. Here, we demonstrate that ATRX associates with a number of the MCM replication complex subunits and that loss of ATRX leads to G4 structure accumulation at newly synthesized DNA. We show that both the helicase domain of ATRX and its H3.3 chaperone function are required to protect cells from G4-induced replicative stress. Furthermore, these activities are upstream of heterochromatin formation mediated by the histone methyltransferase, ESET, which is the critical molecular event that protects cells from G4-mediated stress. In support, tumors carrying mutations in either ATRX or ESET show increased mutation burden at G4-enriched DNA sequences. Overall, our study provides new insights into mechanisms by which ATRX promotes genome stability with important implications for understanding impacts of its loss on human disease.


Author(s):  
Atsuhito Uneda ◽  
Kazuhiko Kurozumi ◽  
Atsushi Fujimura ◽  
Kentaro Fujii ◽  
Joji Ishida ◽  
...  

AbstractGlioblastoma (GBM) is the most lethal primary brain tumor characterized by significant cellular heterogeneity, namely tumor cells, including GBM stem-like cells (GSCs) and differentiated GBM cells (DGCs), and non-tumor cells such as endothelial cells, vascular pericytes, macrophages, and other types of immune cells. GSCs are essential to drive tumor progression, whereas the biological roles of DGCs are largely unknown. In this study, we focused on the roles of DGCs in the tumor microenvironment. To this end, we extracted DGC-specific signature genes from transcriptomic profiles of matched pairs of in vitro GSC and DGC models. By evaluating the DGC signature using single cell data, we confirmed the presence of cell subpopulations emulated by in vitro culture models within a primary tumor. The DGC signature was correlated with the mesenchymal subtype and a poor prognosis in large GBM cohorts such as The Cancer Genome Atlas and Ivy Glioblastoma Atlas Project. In silico signaling pathway analysis suggested a role of DGCs in macrophage infiltration. Consistent with in silico findings, in vitro DGC models promoted macrophage migration. In vivo, coimplantation of DGCs and GSCs reduced the survival of tumor xenograft-bearing mice and increased macrophage infiltration into tumor tissue compared with transplantation of GSCs alone. DGCs exhibited a significant increase in YAP/TAZ/TEAD activity compared with GSCs. CCN1, a transcriptional target of YAP/TAZ, was selected from the DGC signature as a candidate secreted protein involved in macrophage recruitment. In fact, CCN1 was secreted abundantly from DGCs, but not GSCs. DGCs promoted macrophage migration in vitro and macrophage infiltration into tumor tissue in vivo through secretion of CCN1. Collectively, these results demonstrate that DGCs contribute to GSC-dependent tumor progression by shaping a mesenchymal microenvironment via CCN1-mediated macrophage infiltration. This study provides new insight into the complex GBM microenvironment consisting of heterogeneous cells.


2006 ◽  
Vol 14 (3-4) ◽  
pp. 136-140 ◽  
Author(s):  
Gordana Konjevic ◽  
Sandra Stankovic

Metastatic cascade in malignant tumors, including breast cancer, starts with localized invasion of the host tissue. This process, requiring that tumor cells separate from each other, includes loss of homotypic and heterotypic cell adhesion and cell-cell contact inhibition, acquisition of motility, exacerbated by "epithelial-to-mesenchymal transition", and production of proteolytic enzymes which degrade basal membrane and extracellular matrix. In this sense, aside from urokinase type plasminogen activator, increased expression and activity of matrix metalloproteinases (MMPs) is one of the earliest and most sustained events in tumor progression, playing a role in angiogenesis, invasion and metastasis. MMPs are a family of 23 zinc metalloproteinases, secreted as latent pro-enzymes, activated by proteolytic cleavage, and inhibited by the tissue inhibitors of metalloproteinases. The most commonly connected MMPs with the processes of metastasis are MMP-2 (gelatinase A) and MMP-9 (gelatinase B), due to their ability to degrade collagen type IV, major component of vascular basement membrane. MMP-2 and MMP-9 are also required for the switch to the "angiogenic phenotype" during tumor progression and activation of dormant tumor cells. The association of the increase in serum MMP-2 and MMP-9 activity and clinical stage suggests the usefulness of these parameters as markers in the follow-up and prognosis of breast cancer patients. The concept of "stromal-directed therapy" of cancer, with MMP-inhibitors directed against MMPs as targets, is based on the observed MMP up-regulation in tumors.


2014 ◽  
Vol 21 (4) ◽  
pp. 899-906 ◽  
Author(s):  
Arun Satelli ◽  
Abhisek Mitra ◽  
Zachary Brownlee ◽  
Xueqing Xia ◽  
Seth Bellister ◽  
...  

2018 ◽  
Vol 55 (5) ◽  
pp. 663-672 ◽  
Author(s):  
Isao Matsumoto ◽  
James K. Chambers ◽  
Kazumi Nibe ◽  
Ryohei Kinoshita ◽  
Ryohei Nishimura ◽  
...  

The biological behavior and immunohistochemical features of feline renal cell carcinoma (RCC) have not been well characterized. In the present study, immunohistochemical examinations were performed in 12 feline cases of RCC. The RCC consisted of solid ( n = 2), solid-tubular ( n = 2), tubular ( n = 3), papillary ( n = 2), tubulopapillary ( n = 2), and sarcomatoid ( n = 1) type lesions. Of the cases with RCC, 1 developed metastatic disease and 6 cases had no evidence of recurrence at 80 to 2292 days after surgery. One papillary-type tumor had cuboidal cells with scant cytoplasm and monomorphic nuclei, and the other had pseudostratified columnar cells with abundant cytoplasm. Immunohistochemistry revealed that the tumor cells in most cases were positive for cytokeratin (CK)7, CK20, KIT, and CD10, with the exception of cases of the solid type with clear cytoplasm (solid anaplastic), papillary type with columnar cells, and sarcomatoid types. A small number of tumor cells in the solid anaplastic and in the sarcomatoid types were positive for aquaporin-1. Increased expression of N-cadherin and Twist along with nuclear accumulation of β-catenin were observed in the sarcomatoid type. These results indicated that CK, KIT, and CD10 are relatively strongly expressed in most feline RCC. The solid anaplastic RCC exhibited CD10 expression with the absence of distal tubule marker expression. Although immunohistochemistry profiles were relatively consistent with those described in human RCC, the histopathologic features were different from those seen in humans. Epithelial-mesenchymal transition (EMT) marker expression in the current cases may suggest the involvement of an EMT-like mechanism in the development of sarcomatoid RCC in cats.


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