scholarly journals CTDSP1 inhibitor rabeprazole regulates DNA-PKcs dependent topoisomerase I degradation and irinotecan drug resistance in colorectal cancer

2020 ◽  
Author(s):  
Hiroya Matsuoka ◽  
Koji Ando ◽  
Emma J Swayze ◽  
Elizabeth C Unan ◽  
Joseph Mathew ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Drug Resistance ◽  
Topoisomerase I ◽  
Resistance Mechanism ◽  
Rapid Rate ◽  
Rapid Degradation ◽  
The Core ◽  
Upstream Regulator ◽  
Kinase Cascade

AbstractIrinotecan specifically targets topoisomerase I (topoI), and is used to treat various solid tumors, but only 13-32% of patients respond to the therapy. Now, it is understood that the rapid rate of topoI degradation in response to irinotecan causes irinotecan resistance. We have published that the deregulated DNA-PKcs kinase cascade ensures rapid degradation of topoI and is at the core of the drug resistance mechanism of topoI inhibitors, including irinotecan. We also identified CTD small phosphatase 1 (CTDSP1) (a nuclear phosphatase) as a primary upstream regulator of DNA-PKcs in response to topoI inhibitors. Previous reports showed that rabeprazole, a proton pump inhibitor (PPI) inhibits CTDSP1 activity. The purpose of this study was to confirm the effects of rabeprazole on CTDSP1 activity and its impact on colon cancer. Using HCT116 and HT29, with high and low CTDSP1 expression respectively and a retrospective analysis of patients receiving irinotecan with or without rabeprazole have indicated the effect of CTDSP1 in irinotecan response. These results indicate that CTDSP1 promotes sensitivity to irinotecan and rabeprazole prevents this effect, resulting in drug resistance. To ensure the best chance at effective treatment, rabeprazole may not be a suitable PPI for cancer patients treated with irinotecan.

scholarly journals Transforming Growth Factor β Mediates Drug Resistance by Regulating the Expression of Pyruvate Dehydrogenase Kinase 4 in Colorectal Cancer

2016 ◽  
Vol 291 (33) ◽  
pp. 17405-17416 ◽  
Author(s):  
Yang Zhang ◽  
Yi Zhang ◽  
Liying Geng ◽  
Haowei Yi ◽  
Wei Huo ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Drug Resistance ◽  
Cancer Cells ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Kinase ◽  
Dependent Manner ◽  
Colon Cancer Cells ◽  
Pyruvate Dehydrogenase Kinase 4 ◽  
Mouse Xenograft Model

Drug resistance is one of the main causes of colon cancer recurrence. However, our understanding of the underlying mechanisms and availability of therapeutic options remains limited. Here we show that expression of pyruvate dehydrogenase kinase 4 (PDK4) is positively correlated with drug resistance of colon cancer cells and induced by 5-fluorouracil (5-FU) treatment in drug-resistant but not drug-sensitive cells. Knockdown of PDK4 expression sensitizes colon cancer cells to 5-FU or oxaliplatin-induced apoptosis in vitro and increases the effectiveness of 5-FU in the inhibition of tumor growth in a mouse xenograft model in vivo. In addition, we demonstrate for the first time that TGFβ mediates drug resistance by regulating PDK4 expression and that 5-FU induces PDK4 expression in a TGFβ signaling-dependent manner. Mechanistically, knockdown or inhibition of PDK4 significantly increases the inhibitory effect of 5-FU on expression of the anti-apoptotic factors Bcl-2 and survivin. Importantly, studies of patient samples indicate that expression of PDK4 and phosphorylation of Smad2, an indicator of TGFβ pathway activation, show a strong correlation and that both positively associate with chemoresistance in colorectal cancer. These findings indicate that the TGFβ/PDK4 signaling axis plays an important role in the response of colorectal cancer to chemotherapy. A major implication of our studies is that inhibition of PDK4 may have considerable therapeutic potential to overcome drug resistance in colorectal cancer patients, which warrants the development of PDK4-specific inhibitors.

scholarly journals SNP Mutation‐related Genes in Colon Cancer for Monitoring and Prognosis of Patients: A Study Based on the TCGA Database

2020 ◽  
Author(s):  
Xin Liao ◽  
jian li ◽  
Yuxiang Chen ◽  
Haibo Ding ◽  
Chen Liu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Cause Of Death ◽  
Immune Cell ◽  
Tumor Therapy ◽  
Molecular Pathogenesis ◽  
Related Data ◽  
The Core ◽  
Cancer Tumor ◽  
Core Genes

Abstract Background: Cancer is still the leading cause of death in humans, and the fourth leading cause of death is colorectal cancer. Tumor bioinformatics has been developing in recent years, the prognosis and quality of life of patients can be improved by using relevant tools to understand the molecular pathogenesis of colorectal cancer and related prognostic markers. Methods: In this study, Bioinformatics analysis of the snp-related data of colon cancer patients from the TCGA database, it was found that the expression levels of 4 mutated genes (CTTNBP2,DAPK1, DMXL1,SPTBN2) were significantly different from those of wild type and their prognosis. In order to explore how the core genes affect the prognosis of patients, the gene expression of these core genes was analyzed. Results: It was found that the core genes are related to a variety of cancer-related pathway genes, including pi3k-akt pathway and TSC/mTOR pathway. Drug sensitivity analysis showed that SPTBN2 could be inhibited by a variety of drugs, including austocystin D, afatinib, and belinostat. Tumor immunity is closely related to tumor therapy. Through the analysis of immune infiltration of core genes, it was found that DAPK1 and DMXL2 were associated with a variety of immune cell infiltration. Conclusion: Therefore, the detection of genetic mutations and related expressions may be significant in predicting the prognosis of patients with colon cancer. Through the study of high-throughput information excavating, it was discovered that the molecular pathogenesis and prognosis of patients with colon cancer were helpful to the bioinformatics theory.

scholarly journals Curcumin Regulates ERCC1 Expression and Enhances Oxaliplatin Sensitivity in Resistant Colorectal Cancer Cells through Its Effects on miR-409-3p

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Wei Han ◽  
Hongli Yin ◽  
Hao Ma ◽  
Yi Wang ◽  
Desong Kong ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Drug Resistance ◽  
Cancer Cells ◽  
Resistance Mechanism ◽  
Cancer Cell Line ◽  
Colorectal Cancer Cell Line ◽  
Pcr Analysis ◽  
Colorectal Cancer Cells ◽  
Ercc1 Expression

Background. Oxaliplatin (L-OHP) resistance is a major obstacle to the effective treatment of colorectal cancer. The resistance mechanism(s) of colorectal tumors to L-OHP may be related to the regulation of ERCC1 by cancer-expressed miRNAs, but no in-depth studies on the miRNAs that affect drug resistance have been performed. Curcumin (Cur) can reverse the drug resistance of cancer cells, but its effects on ERCC1 expression and miRNA profiles in colorectal cancer have not been studied. Methods. To study the regulation effect of curcumin on ERCC1 expression and its effects on miRNAs, the L-OHP-resistant colorectal cancer cell line HCT116/L-OHP was established. MTT assays were used to evaluate cell proliferation. Flow cytometry was used to investigate apoptotic induction. Western blot and RT-PCR analysis were used to evaluate the expression of drug-associated ERCC1, Bcl-2, GST-π, MRP, P-gp, and survivin. Results. HCT116//L-OHP cell lines were successfully established. The combination of L-OHP and curcumin could reduce L-OHP resistance in vitro. In addition, combination therapy inhibited the expression of ERCC1, Bcl-2, GST-π, MRP, P-gp, and survivin at the mRNA and protein level. Curcumin was found to inhibit ERCC1 through its ability to modulate miR-409-3p. Conclusion. Curcumin can overcome L-OHP resistance in colorectal cancer cells through its effects on miR-409-3p mediated ERCC1 expression.

scholarly journals Rate of Ubiquitination and Proteasomal Degradation of Topoisomerase I Determines Cellular Resistance to Cancer Drug

2021 ◽  
Author(s):  
Elizabeth C Unan ◽  
Hiroya Matsuoka ◽  
Hirofumi Hasuda ◽  
Soumya Malhotra ◽  
Siddhartha Pulukuri ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Topoisomerase I ◽  
Drug Sensitivity ◽  
Response Rate ◽  
Resistance Mechanism ◽  
Proteasomal Degradation ◽  
Cancer Drug ◽  
Primary Mechanism ◽  
Molecular Determinants ◽  
Cellular Pathways

Abstract: Targeted ubiquitination and proteasomal degradation regulates various cellular pathways, and the discovery that CPT induced rapid proteasomal degradation of topoI is the primary mechanism of CPT resistance was novel and compelling. CPTs are used extensively to treat various solid tumors like colorectal, gastric, pancreatic, ovarian and small cell lung cancer. The response rate is low and the classical mechanisms of drug resistance are yet to be validated. Remarkably, CPT resistant cells degrade topoI rapidly by UPP and recently we’ve published the molecular determinants of this pathway. To further understand the UPP mediated CPT resistance mechanism we used targeted proteasome prohibition by ixazomib (MLN9708) to stabilize topoI and determine its impact on CPT resistance. CPT resistant and sensitive cancer lines were both treated with ixazomib in combination with CPT. The CPT induced rate of topoI degradation, and its stabilization by ixazomib, was visualized and estimated by immunohistochemistry, immunofluorescence and immunoblotting assays, MTT and subG1 assays provided the drug sensitivity. Our results demonstrate that cells that degrade topoI rapidly are very resistant to CPT, and ixazomib significantly inhibits CPT induced topoI degradation. Notably, inhibition of proteasomal degradation by ixazomib overcomes the drug resistance and sensitizes the cells for CPTs.

scholarly journals Treatment of HT29 Human Colorectal Cancer Cell Line with Nanocarrier-Encapsulated Camptothecin Reveals Histone Modifier Genes in the Wnt Signaling Pathway as Important Molecular Cues for Colon Cancer Targeting

2021 ◽  
Vol 22 (22) ◽  
pp. 12286
Author(s):  
Aisha Farhana ◽  
Avin Ee-Hwan Koh ◽  
Sangeetha Kothandan ◽  
Abdullah Alsrhani ◽  
Pooi Ling Mok ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Cancer Cells ◽  
Signaling Pathway ◽  
Topoisomerase I ◽  
Interaction Analysis ◽  
Wnt Signaling Pathway ◽  
Genetic Alterations ◽  
Epigenetic Mechanism ◽  
Colorectal Cancer Cell Line

Cancer cells are able to proliferate in an unregulated manner. There are several mechanisms involved that propel such neoplastic transformations. One of these processes involves bypassing cell death through changes in gene expression and, consequently, cell growth. This involves a complex epigenetic interaction within the cell, which drives it towards oncogenic transformations. These epigenetic events augment cellular growth by potentially altering chromatin structures and influencing key gene expressions. Therapeutic mechanisms have been developed to combat this by taking advantage of the underlying oncogenic mechanisms through chemical modulation. Camptothecin (CPT) is an example of this type of drug. It is a selective topoisomerase I inhibitor that is effective against many cancers, such as colorectal cancer. Previously, we successfully formulated a magnetic nanocarrier-conjugated CPT with β-cyclodextrin and iron NPs (Fe3O4) cross-linked using EDTA (CPT-CEF). Compared to CPT alone, it boasts higher efficacy due to its selective targeting and increased solubility. In this study, we treated HT29 colon cancer cells with CPT-CEF and attempted to investigate the cytotoxic effects of the formulation through an epigenetic perspective. By using RNA-Seq, several differentially expressed genes were obtained (p < 0.05). Enrichr was then used for the over-representation analysis, and the genes were compared to the epigenetic roadmap and histone modification database. The results showed that the DEGs had a high correlation with epigenetic modifications involving histone H3 acetylation. Furthermore, a subset of these genes was shown to be associated with the Wnt/β-catenin signaling pathway, which is highly upregulated in a large number of cancer cells. These genes could be investigated as downstream therapeutic targets against the uncontrolled proliferation of cancer cells. Further interaction analysis of the identified genes with the key genes of the Wnt/β-catenin signaling pathway in colorectal cancer identified the direct interactors and a few transcription regulators. Further analysis in cBioPortal confirmed their genetic alterations and their distribution across patient samples. Thus, the findings of this study reveal that colorectal cancer could be reversed by treatment with the CPT-CEF nanoparticle-conjugated nanocarrier through an epigenetic mechanism.

scholarly journals CTDSP1 inhibitor rabeprazole regulates DNA-PKcs dependent topoisomerase I degradation and irinotecan drug resistance in colorectal cancer

PLoS ONE ◽  
2020 ◽  
Vol 15 (8) ◽  
pp. e0228002
Author(s):  
Hiroya Matsuoka ◽  
Koji Ando ◽  
Emma J. Swayze ◽  
Elizabeth C. Unan ◽  
Joseph Mathew ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Drug Resistance ◽  
Topoisomerase I

scholarly journals FOXC1 Regulation of miR-31-5p Confers Oxaliplatin Resistance by Targeting LATS2 in Colorectal Cancer

Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1576 ◽  
Author(s):  
Hsi-Hsien Hsu ◽  
Wei-Wen Kuo ◽  
Hui-Nung Shih ◽  
Sue-Fei Cheng ◽  
Ching-Kuo Yang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Drug Resistance ◽  
Cancer Biology ◽  
Resistance Mechanism ◽  
Stage Iv ◽  
Multi Drug Resistance ◽  
Large Tumor ◽  
Lovo Cells

Colorectal cancer (CRC) is the second leading cause of cancer-related illness worldwide and one of the most common malignancies. Therefore, colorectal cancer research and cases have gained increasing attention. Oxaliplatin (OXA) is currently used in first-line chemotherapy to treat stage III and stage IV metastatic CRC. However, patients undergoing chemotherapy often develop resistance to chemo drugs being used. Evidence has confirmed that microRNAs regulate downstream genes in cancer biology and thereby have roles related to tumor growth, proliferation, invasion, angiogenesis, and multi-drug resistance. The aim of our study is to establish whether miR-31-5p is an oncogene in human colorectal cancers that are resistant to OXA and further confirm its malignant phenotype-associated target molecule. From the results of miRNA microarray assay, we establish that miR-31-5p expression was upregulated in oxaliplatin-resistant (OR)-LoVo cells compared with parental LoVo cells. Moreover, through in vitro and in vivo experiments, we demonstrate that miR-31-5p and large tumor suppressor kinase 2 (LATS2) were inversely related and that miR-31-5p and Forkhead box C1 (FOXC1) were positively correlated in the same LoVo or OR-LoVo cells. Importantly, we reveal a novel drug-resistance mechanism in which the transcription factor FOXC1 binds to the miR-31 promoter to increase the expression of miR31-5p and regulate LATS2 expression, resulting in cancer cell resistance to OXA. These results suggest that miR-31-5p may be a novel biomarker involved in drug resistance progression in CRC patients. Moreover, the FOXC1/miR31-5p/LATS2 drug-resistance mechanism provides new treatment strategies for CRC in clinical trials.

scholarly journals Engineered exosomes for targeted co-delivery of miR-21 inhibitor and chemotherapeutics to reverse drug resistance in colon cancer

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Gaofeng Liang ◽  
Yanliang Zhu ◽  
Doulathunnisa Jaffar Ali ◽  
Tian Tian ◽  
Huantian Xu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Drug Resistance ◽  
Cancer Cells ◽  
Anticancer Drug ◽  
Cancer Cell Line ◽  
Colorectal Cancer Cell Line ◽  
Target Cells ◽  
Main Challenge ◽  
Hct 116

Abstract Background 5-Fluorouracil (5-FU) has been commonly prescribed for patients with colorectal cancer (CRC), but resistance to 5-FU is one of the main reasons for failure in CRC. Recently, microRNAs (miRNAs) have been established as a means of reversing the dilemma by regulating signaling pathways involved in initiation and progression of CRC. However, how to safely and effectively deliver miRNA to target cells becomes a main challenge. Results In this study, Engineered exosomes were exploited to simultaneously deliver an anticancer drug 5-FU and miR-21 inhibitor oligonucleotide (miR-21i) to Her2 expressing cancer cells. Purified engineered exosomes from the donor cells loaded with 5-FU and miR-21i via electroporation to introduce into 5-FU-resistant colorectal cancer cell line HCT-1165FR. Furthermore, systematic administration of 5-FU and miR-21i loaded exosomes in tumor bearing mice indicated a significantly anti-tumor effect. The results showed that the engineered exosome-based 5-FU and miR-21i co-delivery system could efficiently facilitate cellular uptake and significantly down-regulate miR-21 expression in 5-FU resistant HCT-1165FR cell lines. Consequently, the down-regulation of miR-21 induced cell cycle arrest, reduced tumor proliferation, increased apoptosis and rescued PTEN and hMSH2 expressions, regulatory targets of miR-21. Of particular importance was the significant reduction in tumor growth in a mouse model of colon cancer with systematic administration of the targeting miR-21i. More excitedly, the combinational delivery of miR-21i and 5-FU with the engineered exosomes effectively reverse drug resistance and significantly enhanced the cytotoxicity in 5-FU-resistant colon cancer cells, compared with the single treatment with either miR-21i or 5-FU. Conclusion The strategy for co-delivering the functional small RNA and anticancer drug by exosomes foreshadows a potential approach to reverse the drug resistance in CRC and thus to enhance the efficacy of the cancer treatment.

A Tale of Two Colons and Two Cancers

Swiss Surgery ◽  
2003 ◽  
Vol 9 (1) ◽  
pp. 3-7 ◽  
Author(s):  
Gervaz ◽  
Bühler ◽  
Scheiwiller ◽  
Morel
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Adjuvant Chemotherapy ◽  
Splenic Flexure ◽  
Chromosomal Instability ◽  
Proximal Colon ◽  
Colorectal Carcinogenesis ◽  
Physiological Data ◽  
Central Hypothesis ◽  
Group Stratification

The central hypothesis explored in this paper is that colorectal cancer (CRC) is a heterogeneous disease. The initial clue to this heterogeneity was provided by genetic findings; however, embryological and physiological data had previously been gathered, showing that proximal (in relation to the splenic flexure) and distal parts of the colon represent distinct entities. Molecular biologists have identified two distinct pathways, microsatellite instability (MSI) and chromosomal instability (CIN), which are involved in CRC progression. In summary, there may be not one, but two colons and two types of colorectal carcinogenesis, with distinct clinical outcome. The implications for the clinicians are two-folds; 1) tumors originating from the proximal colon have a better prognosis due to a high percentage of MSI-positive lesions; and 2) location of the neoplasm in reference to the splenic flexure should be documented before group stratification in future trials of adjuvant chemotherapy in patients with stage II and III colon cancer.

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