scholarly journals The majority of β-catenin mutations in colorectal cancer is homozygous

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Alexander Arnold ◽  
Moritz Tronser ◽  
Christine Sers ◽  
Aysel Ahadova ◽  
Volker Endris ◽  
...  

Abstract Background β-catenin activation plays a crucial role for tumourigenesis in the large intestine but except for Lynch syndrome (LS) associated cancers stabilizing mutations of β-catenin gene (CTNNB1) are rare in colorectal cancer (CRC). Previous animal studies provide an explanation for this observation. They showed that CTNNB1 mutations induced transformation in the colon only when CTNNB1 was homozygously mutated or when membranous β-catenin binding was hampered by E-cadherin haploinsufficiency. We were interested, if these mechanisms are also found in human CTNNB1 mutated CRCs. Results Among 869 CRCs stabilizing CTNNB1 mutations were found in 27 cases. Homo- or hemizygous CTNNB1 mutations were detected in 74% of CTNNB1 mutated CRCs (13 microsatellite instabile (MSI-H), 7 microsatellite stabile (MSS)) but only in 3% (1/33) of extracolonic CTNNB1 mutated cancers. In contrast to MSS CRC, CTNNB1 mutations at codon 41 or 45 were highly selected in MSI-H CRC. Of the examined three CRC cell lines, β-catenin and E-cadherin expression was similar in cell lines without or with hetereozygous CTNNB1 mutations (DLD1 and HCT116), while a reduced E-cadherin expression combined with cytoplasmic accumulation of β-catenin was found in a cell line with homozygous CTNNB1 mutation (LS180). Reduced expression of E-cadherin in human MSI-H CRC tissue was identified in 60% of investigated cancers, but no association with the CTNNB1 mutational status was found. Conclusions In conclusion, this study shows that in contrast to extracolonic cancers stabilizing CTNNB1 mutations in CRC are commonly homo- or hemizygous indicating a higher threshold of β-catenin stabilization to be required for transformation in the colon as compared to extracolonic sites. Moreover, we found different mutational hotspots in CTNNB1 for MSI-H and MSS CRCs suggesting a selection of different effects on β-catenin stabilization according to the molecular pathway of tumourigenesis. Reduced E-cadherin expression in CRC may further contribute to higher levels of transcriptionally active β-catenin, but it is not directly linked to the CTNNB1 mutational status.

2021 ◽  
Vol 11 ◽  
Author(s):  
Huili Li ◽  
Jiliang Wang ◽  
Kun Huang ◽  
Tao Zhang ◽  
Lu Gao ◽  
...  

NK2 homeobox 5 (Nkx2.5), a homeobox-containing transcription factor, is associated with a spectrum of congenital heart diseases. Recently, Nkx2.5 was also found to be differentially expressed in several kinds of tumors. In colorectal cancer (CRC) tissue and cells, hypermethylation of Nkx2.5 was observed. However, the roles of Nkx2.5 in CRC cells have not been fully elucidated. In the present study, we assessed the relationship between Nkx2.5 and CRC by analyzing the expression pattern of Nkx2.5 in CRC samples and the adjacent normal colonic mucosa (NCM) samples, as well as in CRC cell lines. We found higher expression of Nkx2.5 in CRC compared with NCM samples. CRC cell lines with poorer differentiation also had higher expression of Nkx2.5. Although this expression pattern makes Nkx2.5 seem like an oncogene, in vitro and in vivo tumor suppressive effects of Nkx2.5 were detected in HCT116 cells by establishing Nkx2.5-overexpressed CRC cells. However, Nkx2.5 overexpression was incapacitated in SW480 cells. To further assess the mechanism, different expression levels and mutational status of p53 were observed in HCT116 and SW480 cells. The expression of p21WAF1/CIP1, a downstream antitumor effector of p53, in CRC cells depends on both expression level and mutational status of p53. Overexpressed Nkx2.5 could elevate the expression of p21WAF1/CIP1 only in CRC cells with wild-type p53 (HCT116), rather than in CRC cells with mutated p53 (SW480). Mechanistically, Nkx2.5 could interact with p53 and increase the transcription of p21WAF1/CIP1 without affecting the expression of p53. In conclusion, our findings demonstrate that Nkx2.5 could act as a conditional tumor suppressor gene in CRC cells with respect to the mutational status of p53. The tumor suppressive effect of Nkx2.5 could be mediated by its role as a transcriptional coactivator in wild-type p53-mediated p21WAF1/CIP1 expression.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e14156-e14156
Author(s):  
Armando Orlandi ◽  
Mariantonietta Di Salvatore ◽  
Michele Basso ◽  
Cinzia Bagalà ◽  
Antonia Strippoli ◽  
...  

e14156 Background: Oxaliplatin (Oxa) is widely used in metastatic colorectal cancer, but currently there are not valid predictors of response to this drug. In our recent retrospective clinical study we have shown a greater efficacy of Oxa in patients with metastatic colorectal cancer with mutated (mt) K-RAS. We hypothesized that the mutational status of K-RAS could influence the expression of ERCC1 and cellular Redox status. Methods: We used four cell lines of colorectal cancer: two K-RAS wild type (wt) (HCT-8, HT-29) and two K-RAS mt (SW620, SW480). We evaluated the sensitivity of these cell lines to Oxa by MTT-test and the ERCC1 levels before and after 24h exposure to Oxa by RT-PCR. We silenced K-RAS in a K-RAS mt cell lines to evaluate the impact on Oxa sensitivity and ERCC1 levels. We also silenced ERCC1 in order to confirm the importance of this protein as a Oxa resistance factor. Cellular oxidative stress was determined by DCFDA. Results: The K-RAS mt cell lines were more sensitive to Oxa (p<0.001). The basal levels of ERCC1 did not show significant differences between K-RAS mt and wt cell line, however, after 24h exposure to Oxa, only the K-RAS wt lines showed the ability to induce ERCC1, with a statistically significant difference (p<0.005). The silencing of K-RAS in K-RAS mt cell lines (SW620s) demonstrated to reduce sensitivity to Oxa associated with the acquisition of the ability to induce ERCC1. The silencing of ERCC1 in K-RAS wt cell lines enhance the sensibility to Oxa. The levels of reactive oxygen species were higher in K-RAS mt cell lines. The Pearson correlation test showed a statistically significant relationship between basal levels of ROS and sensitivity to Oxa ("r" -0,988, p<0.01). The baseline levels of ROS were higher SW620 than the line SW620s. The administration of Oxa in these cell lines resulted in a statistically higher fluorescence index in SW620 versus SW620s (p<0.003). Conclusions: The K-RAS mutated cell lines were more sensitive to Oxa. This feature seems to be secondary to the inability of these cells to induce ERCC1 after exposure to Oxa and to the synergism between K-RAS mutation and Oxa in increasing oxidative stress. K-RAS can thus be a predictor of response to Oxa in colorectal cancer.


2020 ◽  
Author(s):  
Ye Jin ◽  
Lingli Yu ◽  
Bin Zhang ◽  
Yun Chen ◽  
Changfeng Liu ◽  
...  

Abstract Background: Circ_0026344 was reported to be associated with the metastasis of colorectal cancer (CRC). This study aimed to investigate the expression of circ_0026344 in CRC and the effect mechanisms of circ_0026344 on CRC.Methods: The expressions of circ_0026344 and miR-31 in clinical CRC tissues or CRC cell lines were analyzed by qPCR. The target of circ_0026344 was predicted and verified by CircInteractome and dual-luciferase reporter assays. The correlation between circ_0026344 and miR-31 expression was analyzed using Pearson analysis. After the CRC cells were overexpressed circ_0026344 or miR-31 or silenced circ_0026344, the viability, apoptosis, migration, and invasion of CRC cells were evaluated by CCK-8, flow cytometry, wound healing, and transwell. Also, the expressions of miR-31, Bcl-2, Bax, E-cadherin, and N-cadherin in the cells were detected by qPCR or Western blot. Results: Circ_0026344 was low-expressed in CRC tissues and cell lines. Circ_0026344 sponged miR-31 which was high-expressed in CRC tissues. The expression of circ_0026344 was negatively correlated to the expression of miR-31. The miR-31 expression could be down-regulated by circ_0026344 overexpression. Circ_0026344 overexpression inhibited the cell viability, migration, and invasion; and enhanced the apoptosis of CRC cells. Circ_0026344 overexpression decreased the expressions of Bcl-2 and N-cadherin and increased the expressions of Bax and E-cadherin in CRC cells. Circ_0026344 silencing and miR-31 overexpression had an opposite effect on CRC cells as circ_0026344 overexpression. Furthermore, miR-31 overexpression counteracted the effect of circ_0026344 overexpression.Conclusion: Circ_0026344 overexpression inhibited the migration, invasion, and enhanced apoptosis of CRC cells by sponging miR-31.


2019 ◽  
Vol 2 (6) ◽  
pp. e201900517 ◽  
Author(s):  
Jonathan Ronen ◽  
Sikander Hayat ◽  
Altuna Akalin

Colorectal cancer (CRC) is a common cancer with a high mortality rate and a rising incidence rate in the developed world. Molecular profiling techniques have been used to better understand the variability between tumors and disease models such as cell lines. To maximize the translatability and clinical relevance of in vitro studies, the selection of optimal cancer models is imperative. We have developed a deep learning–based method to measure the similarity between CRC tumors and disease models such as cancer cell lines. Our method efficiently leverages multiomics data sets containing copy number alterations, gene expression, and point mutations and learns latent factors that describe data in lower dimensions. These latent factors represent the patterns that are clinically relevant and explain the variability of molecular profiles across tumors and cell lines. Using these, we propose refined CRC subtypes and provide best-matching cell lines to different subtypes. These findings are relevant to patient stratification and selection of cell lines for early-stage drug discovery pipelines, biomarker discovery, and target identification.


Oncotarget ◽  
2018 ◽  
Vol 9 (29) ◽  
pp. 20578-20589 ◽  
Author(s):  
Ángela L. Riffo-Campos ◽  
Francisco Gimeno-Valiente ◽  
Fernanda M. Rodríguez ◽  
Andrés Cervantes ◽  
Gerardo López-Rodas ◽  
...  

2012 ◽  
Vol 30 (4_suppl) ◽  
pp. 489-489 ◽  
Author(s):  
Armando Orlandi ◽  
Mariantonietta Di Salvatore ◽  
Michele Basso ◽  
Cinzia Bagalà ◽  
Antonia Strippoli ◽  
...  

489 Background: Oxaliplatin is widely used in metastatic colorectal cancer, but currently there are not valid predictors of response to this drug. In our recent retrospective clinical study we have shown a greater efficacy of Oxaliplatin in patients with metastatic colorectal cancer with mutated (mt) K-RAS. We hypothesized that the mutational status of K-RAS could influence the expression of ERCC1, one of the main mechanisms of Oxaliplatin resistance. Methods: We used four cell lines of colorectal cancer: two K-RAS wild type (wt) (HCT-8 and HT-29) and two K-RAS mt (SW620 and SW480). We evaluated the sensitivity of these cell lines to Oxaliplatin by MTT-test and the ERCC1 levels before and after 24 h exposure to Oxaliplatin by Real-Time PCR. We silenced K-RAS in a K-RAS mt cell line to evaluate the impact on Oxaliplatin sensitivity and ERCC1 levels. We also silenced ERCC1 in order to confirm the importance of this protein as a Oxaliplatin resistance factor. Results: The K-RAS mt cell lines were more sensitive to Oxaliplatin (OR 2.68; IC 95% 1.511-4.757 p<0.001). The basal levels of ERCC1 did not show significant differences between K-RAS mt and wt cell line, however, after 24 h exposure to Oxaliplatin, only the K-RAS wt lines showed the ability to induce ERCC1, with a statistically significant difference (OR 42.9 IC 95% 17.260-106.972 p<0.0005). The silencing of K-RAS in K-RAS mt cell lines demonstrated to reduce sensitivity to Oxaliplatin associated with the acquisition of the ability to induce ERCC1. The silencing of ERCC1 in K-RAS wt cell lines enhance the sensibility to Oxaliplatin. Conclusions: The K-RAS mutated cell lines were more sensitive to Oxaliplatin. This feature seems to be secondary to the inability of these cells to induce ERCC1 after exposure to Oxaliplatin. K-RAS can thus be a predictor of response to Oxaliplatin in colorectal cancer representing a surrogate for ability to induce ERCC1.


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