scholarly journals Anticancer Opportunity Created by Loss of Tumor Suppressor Genes

2016 ◽  
Vol 15 (6) ◽  
pp. 729-731 ◽  
Author(s):  
Xue Hui-Ying ◽  
Zhang Da-Hong ◽  
Ji Li-Juan ◽  
Lu Xiao-Jie

Deletion of oncosuppressors occurs frequently in the cancer genome. A great deal of effort has been made to therapeutically restore the lost function of oncosuppressors, with little clinically translatable success, however. Reassuringly, besides the disappointing restoration endeavors, oncosuppressor loss can be therapeutically exploited in several other ways, such as the “synthetic lethality” strategies and the “therapeutic vulnerability” created by codeletion of neighboring genes. The study by Liu et al showed that codeletion of p53 and a neighboring essential gene POLR2A rendered colon cancer cells highly sensitive to further inhibition of POLR2A both in vitro and in vivo. In recent years, several studies have reported similar phenomenon in a wide range of cancer types. In this focus article, we will introduce several kinds of anticancer opportunities created by the loss of oncosuppressors and discuss their mechanisms. Given the frequency of oncosuppressor loss in cancer, its therapeutic exploitation rather merits further investigation and may open a new window for oncotherapy.

2013 ◽  
Vol 144 (5) ◽  
pp. S-166-S-167
Author(s):  
Karen Boland ◽  
Caoimhin Concannon ◽  
Niamh McCawley ◽  
Elaine W. Kay ◽  
Deborah McNamara ◽  
...  

2019 ◽  
Vol 8 (12) ◽  
pp. 5662-5672 ◽  
Author(s):  
Sonoko Chikamatsu ◽  
Ken Saijo ◽  
Hiroo Imai ◽  
Koichi Narita ◽  
Yoshifumi Kawamura ◽  
...  

Author(s):  
Junhui Yu ◽  
Kui Yang ◽  
Jianbao Zheng ◽  
Wei Zhao ◽  
Xuejun Sun

Abstract The tumor-suppressive role of Farnesoid X receptor (FXR) in colorectal tumorigenesis supports restoring FXR expression as a novel therapeutic strategy. However, the complicated signaling network and tumor heterogeneity hinder the effectiveness of FXR agonists in the clinical setting. These difficulties highlight the importance of identifying drug combinations with potency and specificity to enhance the antitumor effects of FXR agonists. In this study, we found that the β-catenin level affected the antitumor effects of the FXR agonist OCA on colon cancer cells. Mechanistic studies identified a novel FXR/β-catenin complex in colon cancer cells. Furthermore, the depletion of β-catenin expedited FXR nuclear localization and enhanced its occupancy of the SHP promoter and thereby sensitized colon cancer cells to OCA. Furthermore, we utilized a drug combination study and identified that the antiparasitic drug nitazoxanide (NTZ) abrogated β-catenin expression and acted synergistically with OCA in colon cancer cells. The combination of OCA plus NTZ exerts synergistic tumor inhibition in CRC both in vitro and in vivo by cooperatively upregulating SHP expression. In conclusion, our study offers useful evidence for the clinical use of FXR agonists combined with β-catenin inhibitors in combating CRC.


Author(s):  
Longgang Wang ◽  
Jinxiang Guo ◽  
Jin Zhou ◽  
Dongyang Wang ◽  
Xiuwen Kang ◽  
...  

Abstract Background Colon cancer represents one of the leading causes of gastrointestinal tumors in industrialized countries, and its incidence appears to be increasing at an alarming rate. Accumulating evidence has unveiled the contributory roles of cancer stem cells (CSCs) in tumorigenicity, recurrence, and metastases. The functions of NF-kappa B (NF-κB) activation on cancer cell survival, including colon cancer cells have encouraged us to study the role of NF-κB in the maintenance of CSCs in colon cancer. Methods Tumor samples and matched normal samples were obtained from 35 colon cancer cases. CSCs were isolated from human colon cancer cell lines, where the stemness of the cells was evaluated by cell viability, colony-forming, spheroid-forming, invasion, migration, and apoptosis assays. NF-κB activation was then performed in subcutaneous tumor models of CSCs by injecting lipopolysaccharides (LPS) i.p. Results We found that NF-κB activation could reduce the expression of miR-195-5p and miR-497-5p, where these two miRNAs were determined to be downregulated in colon cancer tissues, cultured colon CSCs, and LPS-injected subcutaneous tumor models. Elevation of miR-195-5p and miR-497-5p levels by their specific mimic could ablate the effects of NF-κB on the stemness of colon cancer cells in vivo and in vitro, suggesting that NF-κB could maintain the stemness of colon cancer cells by downregulating miR-195-5p/497–5p. MCM2 was validated as the target gene of miR-195-5p and miR-497-5p in cultured colon CSCs. Overexpression of MCM2 was shown to restore the stemness of colon cancer cells in the presence of miR-195-5p and miR-497-5p, suggesting that miR-195-5p and miR-497-5p could impair the stemness of colon cancer cells by targeting MCM2 in vivo and in vitro. Conclusions Our work demonstrates that the restoration of miR-195-5p and miR-497-5p may be a therapeutic strategy for colon cancer treatment in relation to NF-κB activation.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 4060-4060
Author(s):  
Sang Hee Cho ◽  
Jo-Heon Kim ◽  
Chang-Soo Hong ◽  
Eun-Gene Sun ◽  
Kyung-Hyun Ryu ◽  
...  

4060 Background: Anti-EGFR therapy has been used as a standard treatment for metastatic colon cancer, but the innate resistance is still issues of increasing significance. Fibroblast growth factor receptor 4 (FGFR4) plays an important role in cell proliferation, invasion and anti-apoptosis, through the pathway of MAPK-ERK and PI3K-AKT. We investigated potential crosstalk between FGFR4 and EGFR signaling to identify new resistant mechanism of anti-EGFR therapy and how to overcome it in colon cancer. Methods: RNA-Seq was used to identify the associated signal pathway and down targets induced by FGFR4. Molecular studies including RTK array, RT-qPCR, western blotting were performed to validate the interaction between FGFR4 and EGFR signaling in vitro and in vivo. Next, the effect of FGFR4 in cetuximab resistance was investigated in vitro and in colon cancer patients. Results: FGFR4 overexpression in colon cancer cells activates downstream signaling, such as, PI3K/Akt and RAS/RAF/Erk pathway. Gene Ontology (GO) analysis from RNA-seq revealed that differentially expressed genes (DEGs) altered by expression of FGFR4 were related to biological functions, including cell proliferation, epidermal growth factor receptor signaling, NIK/NF-kB signaling, interferon-gamma signaling, wound healing. RT–qRCR showed that FGFR4 promotes the EGFR and ErbB3 by inducing the expression of EGFR ligands such as AREG, BTC, EREG, HBEGF. In vivo tumorigenesis, we found that FGFR4 promotes tumor growth and high expression of AREG in xenograft tumors. FGFR4 expression reduced the sensitivity to cetuximab in colon cancer cells and synergistic effect was shown when treated with FGFR4 inhibitor with cetuximab. A positive correlation between FGFR4 and AREG expression was observed in cancer, but not in normal tissues and high FGFR4 or AREG expression showed significantly inferior overall survival than low expression in patients treated with cetuximab for metastatic colon cancer. Conclusions: We demonstrated a pivotal mechanism of FGFR4 in colon cancer progression and cetuximab resistance through inducing AREG. Our data point to FGFR4 as a new biomarker to predict cetuximab response and dual targeting of FGFR4 and EGFR may be a promising treatment modality for colon cancer.


2008 ◽  
Vol 15 (1) ◽  
pp. 201-207 ◽  
Author(s):  
Guiying Zhang ◽  
Ting Liu ◽  
Yong-Heng Chen ◽  
Yuxiang Chen ◽  
Meihua Xu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document