scholarly journals Genetics of Colorectal Cancer: Role of p53

2020 ◽  
Vol 10 (6-s) ◽  
pp. 183-185
Author(s):  
Rajashri Champanery ◽  
Drashti Joshi
Keyword(s):  
Colorectal Cancer ◽  
Tumor Suppressor ◽  
Tp53 Mutation ◽  
Human Cancer ◽  
Tumor Development ◽  
Tp53 Gene ◽  
Pathological Process ◽  
Functional Roles ◽  
Different Types

The tumor suppressor TP53 gene is one of the most frequently mutated in different types of human cancer. Particularly in colorectal cancer (CRC), it is believed that TP53 mutations play a role in the adenoma-carcinoma transition of tumors during pathological process. The TP53 mutation is the key step driving the transition from adenoma to adenocarcinoma. The functional roles of TP53 mutation in tumor development have been comprehensively investigated. In this mini review, we comprehensively summarize the p53 mutants in CRC progression and discuss the current strategies for p53 mutants in malignancies. Keywords: p53 mutants, colorectal cancer, Tp53 mutation

scholarly journals MicroRNA-491-5p inhibit gastric cancer development by targeting EMT, cell adhesion genes and IFITM2

2020 ◽  
Author(s):  
Zhijian Wei ◽  
Lixiang Zhang ◽  
Angqing Li ◽  
Chuanhong Li ◽  
Wenxiu Han ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Adhesion ◽  
Tumor Suppressor ◽  
Tumor Development ◽  
Migration And Invasion ◽  
Different Types ◽  
High Level

Abstract Gastric cancer (GC) is one of the deadliest cancers in China. And, it can be regulated by MicroRNAs (miRNAs) generally. miR-491-5p function as a tumor suppressor in different types of cancer, but we still don’t know the role of miR-491-5p in gastric cancer. In this study, we found that high level of miR-491-5p caused a weak cell proliferation, migration and invasion abilities. In order to explore the role of miR-491-5p in vivo, we set a xenograft mouse model, and also found that high level of miR-491-5p suppressed tumor growth. Moreover, we found that miR-491-5p regulate the tumor development thought regulate the expression of EMT, cell adhesion genes and IFITM2. These data show that miR-491-5p function as a tumor suppressor in GC both in vitro and in vivo .

scholarly journals Targeting the Oncogenic p53 Mutants in Colorectal Cancer and Other Solid Tumors

2019 ◽  
Vol 20 (23) ◽  
pp. 5999 ◽  
Author(s):  
Hui Li ◽  
Jinglin Zhang ◽  
Joanna Hung Man Tong ◽  
Anthony Wing Hung Chan ◽  
Jun Yu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Solid Tumors ◽  
Tp53 Mutation ◽  
Tumor Development ◽  
Migration And Invasion ◽  
Cancer Type ◽  
Wild Type ◽  
Functional Roles ◽  
Common Cancer ◽  
Common Cancer Type

Colorectal cancer (CRC) is a kind of solid tumor and the third most common cancer type in the world. It is a heterogeneous disease characterized by genetic and epigenetic aberrations. The TP53 mutation is the key step driving the transition from adenoma to adenocarcinoma. The functional roles of TP53 mutation in tumor development have been comprehensively investigated. In CRC, TP53 mutation was associated with poor prognosis and chemoresistance. A gain of function (GOF) of p53 mutants promotes cell proliferation, migration and invasion through multiple mechanisms. Restoring wild type p53 function, depleting p53 mutants, or intervention by targeting the oncogenic downstreams provides potential therapeutic strategies. In this review, we comprehensively summarize the GOF of p53 mutants in CRC progression as well as in some other solid tumors, and discuss the current strategies targeting p53 mutants in malignancies.

scholarly journals A polymorphism in the tumor suppressor p53 affects aging and longevity in mouse models

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Yuhan Zhao ◽  
Lihua Wu ◽  
Xuetian Yue ◽  
Cen Zhang ◽  
Jianming Wang ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Tumor Development ◽  
Early Death ◽  
Tp53 Gene ◽  
Tumor Suppressor P53 ◽  
P53 Codon 72 ◽  
Codon 72 ◽  
And Function ◽  
Direct Genetic Evidence

Tumor suppressor p53 prevents early death due to cancer development. However, the role of p53 in aging process and longevity has not been well-established. In humans, single nucleotide polymorphism (SNP) with either arginine (R72) or proline (P72) at codon 72 influences p53 activity; the P72 allele has a weaker p53 activity and function in tumor suppression. Here, employing a mouse model with knock-in of human TP53 gene carrying codon 72 SNP, we found that despite increased cancer risk, P72 mice that escape tumor development display a longer lifespan than R72 mice. Further, P72 mice have a delayed development of aging-associated phenotypes compared with R72 mice. Mechanistically, P72 mice can better retain the self-renewal function of stem/progenitor cells compared with R72 mice during aging. This study provides direct genetic evidence demonstrating that p53 codon 72 SNP directly impacts aging and longevity, which supports a role of p53 in regulation of longevity.

Role of Regulatory Oncogenic or Tumor Suppressor miRNAs of PI3K/AKT Signaling Axis in the Pathogenesis of Colorectal Cancer

2019 ◽  
Vol 24 (39) ◽  
pp. 4605-4610 ◽  
Author(s):  
Atena Soleimani ◽  
Farzad Rahmani ◽  
Gordon A. Ferns ◽  
Mikhail Ryzhikov ◽  
Amir Avan ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Tumor Suppressor ◽  
Current Knowledge ◽  
Akt Signaling ◽  
Tumor Tissues ◽  
Radio Therapy ◽  
Signaling Axis ◽  
Cancer Tumor ◽  
Novel Biomarkers

Colorectal cancer (CRC) is the leading cause of cancer death worldwide and its incidence is increasing. In most patients with CRC, the PI3K/AKT signaling axis is over-activated. Regulatory oncogenic or tumor suppressor microRNAs (miRNAs) for PI3K/AKT signaling regulate cell proliferation, migration, invasion, angiogenesis, as well as resistance to chemo-/radio-therapy in colorectal cancer tumor tissues. Thus, regulatory miRNAs of PI3K/AKT/mTOR signaling represent novel biomarkers for new patient diagnosis and obtaining clinically invaluable information from post-treatment CRC patients for improving therapeutic strategies. This review summarizes the current knowledge of miRNAs’ regulatory roles of PI3K/AKT signaling in CRC pathogenesis.

scholarly journals Interleukin-11-expressing fibroblasts have a unique gene signature correlated with poor prognosis of colorectal cancer

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Takashi Nishina ◽  
Yutaka Deguchi ◽  
Daisuke Ohshima ◽  
Wakami Takeda ◽  
Masato Ohtsuka ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Tumor Cells ◽  
Human Cancer ◽  
Tumor Development ◽  
Gene Signature ◽  
Free Survival ◽  
Expression Of Genes ◽  
Reporter Mice ◽  
Interleukin 11

AbstractInterleukin (IL)-11 is a member of the IL-6 family of cytokines and is involved in multiple cellular responses, including tumor development. However, the origin and functions of IL-11-producing (IL-11+) cells are not fully understood. To characterize IL-11+ cells in vivo, we generate Il11 reporter mice. IL-11+ cells appear in the colon in murine tumor and acute colitis models. Il11ra1 or Il11 deletion attenuates the development of colitis-associated colorectal cancer. IL-11+ cells express fibroblast markers and genes associated with cell proliferation and tissue repair. IL-11 induces the activation of colonic fibroblasts and epithelial cells through phosphorylation of STAT3. Human cancer database analysis reveals that the expression of genes enriched in IL-11+ fibroblasts is elevated in human colorectal cancer and correlated with reduced recurrence-free survival. IL-11+ fibroblasts activate both tumor cells and fibroblasts via secretion of IL-11, thereby constituting a feed-forward loop between tumor cells and fibroblasts in the tumor microenvironment.

scholarly journals Species functional traits and abundance as drivers of multiplex ecological networks: first empirical quantification of inter-layer edge weights

2020 ◽  
Vol 287 (1939) ◽  
pp. 20202127
Author(s):  
S. Hervías-Parejo ◽  
C. Tur ◽  
R. Heleno ◽  
M. Nogales ◽  
S. Timóteo ◽  
...  
Keyword(s):  
Species Traits ◽  
Abundant Species ◽  
Modular Organization ◽  
Vertebrate Species ◽  
Multilayer Network ◽  
Functional Roles ◽  
Different Types ◽  
Seed Dispersers ◽  
Natural Communities

Many vertebrate species act as both plant pollinators and seed-dispersers, thus interconnecting these processes, particularly on islands. Ecological multilayer networks are a powerful tool to explore interdependencies between processes; however, quantifying the links between species engaging in different types of interactions (i.e. inter-layer edges) remains a great challenge. Here, we empirically measured inter-layer edge weights by quantifying the role of individually marked birds as both pollinators and seed-dispersers of Galápagos plant species over an entire year. Although most species (80%) engaged in both functions, we show that only a small proportion of individuals actually linked the two processes, highlighting the need to further consider intra-specific variability in individuals' functional roles. Furthermore, we found a high variation among species in linking both processes, i.e. some species contribute more than others to the modular organization of the multilayer network. Small and abundant species are particularly important for the cohesion of pollinator seed-dispersal networks, demonstrating the interplay between species traits and neutral processes structuring natural communities.

scholarly journals Hypermethylation of DHRS3 as a Novel Tumor Suppressor Involved in Tumor Growth and Prognosis in Gastric Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Sha Sumei ◽  
Kong Xiangyun ◽  
Chen Fenrong ◽  
Sun Xueguang ◽  
Hu Sijun ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Tumor Suppressor ◽  
Tumor Growth ◽  
Human Cancer ◽  
Methylation Status ◽  
Ectopic Expression ◽  
Survival Times

Background/AimsThe role of DHRS3 in human cancer remains unclear. Our study explored the role of DHRS3 in gastric cancer (GC) and its clinicopathological significance and associated mechanisms.MaterialsBisulfite-assisted genomic sequencing PCR and a Mass-Array system were used to evaluate and quantify the methylation levels of the promoter. The expression levels and biological function of DHRS3 was examined by both in vitro and in vivo assays. A two-way hierarchical cluster analysis was used to classify the methylation profiles, and the correlation between the methylation status of the DHRS3 promoter and the clinicopathological characteristics of GC were then assessed.ResultsThe DHRS3 promoter was hypermethylated in GC samples, while the mRNA and protein levels of DHRS3 were significantly downregulated. Ectopic expression of DHRS3 in GC cells inhibited cell proliferation and migration in vitro, decreased tumor growth in vivo. DHRS3 methylation was correlated with histological type and poor differentiation of tumors. GC patients with high degrees of CpG 9.10 methylation had shorter survival times than those with lower methylation.ConclusionDHRS3 was hypermethylated and downregulated in GC patients. Reduced expression of DHRS3 is implicated in gastric carcinogenesis, which suggests DHRS3 is a tumor suppressor.

scholarly journals Unveiling role of sphingosine-1-phosphate receptor 2 as a brake of epithelial stem cell proliferation and a tumor suppressor in colorectal cancer

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Luciana Petti ◽  
Giulia Rizzo ◽  
Federica Rubbino ◽  
Sudharshan Elangovan ◽  
Piergiuseppe Colombo ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Stem Cells ◽  
Cell Proliferation ◽  
Stem Cell ◽  
Tumor Suppressor ◽  
Normal Mucosa ◽  
Intestinal Stem Cells ◽  
Intestinal Epithelial ◽  
Sphingosine 1 Phosphate

Abstract Background Sphingosine-1-phosphate receptor 2 (S1PR2) mediates pleiotropic functions encompassing cell proliferation, survival, and migration, which become collectively de-regulated in cancer. Information on whether S1PR2 participates in colorectal carcinogenesis/cancer is scanty, and we set out to fill the gap. Methods We screened expression changes of S1PR2 in human CRC and matched normal mucosa specimens [N = 76]. We compared CRC arising in inflammation-driven and genetically engineered models in wild-type (S1PR2+/+) and S1PR2 deficient (S1PR2−/−) mice. We reconstituted S1PR2 expression in RKO cells and assessed their growth in xenografts. Functionally, we mimicked the ablation of S1PR2 in normal mucosa by treating S1PR2+/+ organoids with JTE013 and characterized intestinal epithelial stem cells isolated from S1PR2−/−Lgr5-EGFP- mice. Results S1PR2 expression was lost in 33% of CRC; in 55%, it was significantly decreased, only 12% retaining expression comparable to normal mucosa. Both colitis-induced and genetic Apc+/min mouse models of CRC showed a higher incidence in size and number of carcinomas and/or high-grade adenomas, with increased cell proliferation in S1PR2−/− mice compared to S1PR2+/+ controls. Loss of S1PR2 impaired mucosal regeneration, ultimately promoting the expansion of intestinal stem cells. Whereas its overexpression attenuated cell cycle progression, it reduced the phosphorylation of AKT and augmented the levels of PTEN. Conclusions In normal colonic crypts, S1PR2 gains expression along with intestinal epithelial cells differentiation, but not in intestinal stem cells, and contrasts intestinal tumorigenesis by promoting epithelial differentiation, preventing the expansion of stem cells and braking their malignant transformation. Targeting of S1PR2 may be of therapeutic benefit for CRC expressing high Lgr5. Graphical Abstract. Schematic drawing of the role of S1PR2 in normal mucosa and colorectal cancer. In the normal mucosa, S1PR2 is highly expressed by differentiated cells at the upper region of both colon and intestinal crypts (S1PR2 ON), but not by the undifferentiated stem cell at the base of the crypts (S1PR2 OFF), in which acts as a negative proliferative regulator promoting epithelial differentiation. Its loss leads to the expansion of stem cells and reduced levels of PTEN and Axin-2, two negative regulators respectively of PI3K/AKT and Wnt signaling that control β-catenin signaling. The translocation of β-catenin into the nucleus promotes the transcription of target genes involved in the proliferation and malignant transformation. Thereby, S1PR2 works in the intestine as a tumor suppressor

scholarly journals Distinct TP53 Mutation Types Exhibit Increased Sensitivity to Ferroptosis Independently of Changes in Iron Regulatory Protein Activity

2020 ◽  
Vol 21 (18) ◽  
pp. 6751
Author(s):  
Laurie R. Thompson ◽  
Thais G. Oliveira ◽  
Evan R. Hermann ◽  
Winyoo Chowanadisai ◽  
Stephen L. Clarke ◽  
...  
Keyword(s):  
Cell Death ◽  
Tumor Suppressor ◽  
Tp53 Mutation ◽  
Rna Binding ◽  
Iron Acquisition ◽  
Regulatory Protein ◽  
Tp53 Gene ◽  
Iron Regulatory Protein ◽  
Regulatory Pathways ◽  
Increased Sensitivity

The tumor suppressor gene TP53 is the most commonly mutated gene in human cancer. In addition to loss of tumor suppressor functions, mutations in TP53 promote cancer progression by altering cellular iron acquisition and metabolism. A newly identified role for TP53 in the coordination of iron homeostasis and cancer cell survival lies in the ability for TP53 to protect against ferroptosis, a form of iron-mediated cell death. The purpose of this study was to determine the extent to which TP53 mutation status affects the cellular response to ferroptosis induction. Using H1299 cells, which are null for TP53, we generated cell lines expressing either a tetracycline inducible wild-type (WT) TP53 gene, or a representative mutated TP53 gene from six exemplary “hotspot” mutations in the DNA binding domain (R273H, R248Q, R282W, R175H, G245S, and R249S). TP53 mutants (R273H, R248Q, R175H, G245S, and R249S) exhibited increased sensitivity ferroptosis compared to cells expressing WT TP53. As iron-mediated lipid peroxidation is critical for ferroptosis induction, we hypothesized that iron acquisition pathways would be upregulated in mutant TP53-expressing cells. However, only cells expressing the R248Q, R175H, and G245S TP53 mutation types exhibited statistically significant increases in spontaneous iron regulatory protein (IRP) RNA binding activity following ferroptosis activation. Moreover, changes in the expression of downstream IRP targets were inconsistent with the observed differences in sensitivity to ferroptosis. These findings reveal that canonical iron regulatory pathways are bypassed during ferroptotic cell death. These results also indicate that induction of ferroptosis may be an effective therapeutic approach for tumor cells expressing distinct TP53 mutation types.

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