scholarly journals Deficient or R273H and R248W Mutations of p53 Promote Chemoresistance to 5-FU via TCF21/CD44 Axis-Mediated Enhanced Stemness in Colorectal Carcinoma

Author(s):  
Xiaolei Gao ◽  
Xuan Zheng ◽  
Yixin Zhang ◽  
Liying Dong ◽  
Liangjie Sun ◽  
...  

Background: p53 mutations are highly frequent in various human cancers and are reported to contribute to tumor malignance and chemoresistance. In this study, we explored the mechanism by which mutant p53 promotes carcinogenesis and chemoresistance and provided novel insights into cancer therapy.Materials and methods: A total of 409 patients with colorectal carcinoma from TCGA database were subdivided into two groups according to the p53 status, namely, mutant p53 and wild-type p53, following with GSEA analysis. The differences of the clinicopathologic index were also analyzed. Two HCT116 cell lines containing hot spots at codons R273H and R248W of p53 were constructed based on HCT116 with knockout p53, respectively. Cell viability, mobility, clonogenesis, and stemness were detected by CCK8, transwell migration and invasion, colonogenic, and sphere formation assays. Resistance to 5-FU was examined by live-dead staining and flow cytometry. qPCR, Western blot, and luciferase reporter assay were performed to identify that deficient or mutant p53 promoted chemoresistance of the colorectal carcinoma cell line HCT116 through the TCF21/CD44 signaling pathway, with the following rescue assays by overexpression of TCF21 and knockdown of CD44.Results: Patients with recurrence harbor a higher frequency of mutant p53 than those without recurrence (p < 0.05). The mutant p53 group developed a larger tumor than the wild-type one. GSEA analysis showed that oncogenic signatures were enriched in the mutant p53 group. Extracellular assays showed that cancer cells with deficient or mutant p53 (R273H and R248W, respectively) promoted colon cancer cell growth, migration, invasion, and stemness. The mutant cancer cells were also observed to be significantly resistant to 5-FU. Xenografts also confirmed that HCT116 cells harboring deficient or mutant p53 promoted cancer growth and 5-FU tolerance. Luciferase reporter assay showed that deficient or mutant p53 R237H and R248W endowed cancer cells with chemoresistance by activating CD44 via repressing the nuclear transcription factor TCF21 expression. Overexpression of TCF21 or knockdown of CD44 could rescue the sensitivity to 5-FU in deficient and mutant p53 HCT116 cell lines.Conclusion: Our results, for the first time, reveal a novel deficient or mutant p53/TCF21/CD44 signaling pathway which promotes chemoresistance in colorectal carcinoma. The axis could be an effective therapeutic strategy against deficient- or mutant p53-driven chemoresistance.

2020 ◽  
Vol 19 (1) ◽  
pp. 39-44
Author(s):  
Bangming Pu ◽  
Yong Cao ◽  
Yan Li ◽  
Li Tang ◽  
Jiyi Xia ◽  
...  

Purpose: To explore the molecular function of miR-196b-5p in hepatocellular carcinoma (HCC).Methods: MiR-196b-5p expression levels in HCC tissue samples were assessed by qRT-PCR. MiR-196b-5p was knocked-down or over-expressed in HepG2 cells by transfecting the cells with plasmids expressing either a miR-196b-5p inhibitor or mimic, respectively, while cell proliferation was  assessed by MTT assay. The interaction of miR-196b-5p with target molecules was confirmed using luciferase reporter assay. Cell cycle was investigated by flow cytometry, while NFκBIA expression was assessed by western blotting.Results: MiR-196b-5p was over-expressed in HCC, and miR-196b-5p expression levels in patients with HCC were related to tumor grade. MiR-196b-5p over-expression promoted cell proliferation and colony formation and suppressed cell cycle arrest and apoptosis. The results of luciferase reporter assay showed that miR-196b-5p reduced NFκBIA expression in HepG2 cells by binding to a response element in the 3′ UTR of NFκBIA. Further investigation showed that NFκBIA interacts with NFκB1 and reduces the concentration of NFκB1 in HepG2 cells. The promoter of ATP-binding cassette sub-family B member 1 (ABCB1) was also targeted and bound by NFκB1, which altered the expression of ABCB1 in HepG2 cells.Conclusion: MiR-196b-5p regulates cell proliferation in drug-resistant HCC cell lines via activation of the NFκB/ABCB1 signaling pathway. Keywords: Hepatocellular carcinoma, miR-196b-5p, NFκBIA, NFκB1, ABCB1


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tian-Jun Chen ◽  
Qi Zheng ◽  
Fei Gao ◽  
Tian Yang ◽  
Hui Ren ◽  
...  

Abstract Background MicroRNAs (miRNAs) are involved in the oncogenesis, development and transformation of lung squamous cell carcinoma (LUSC). miR-665 is clinically significant and acts as a pivotal function in some cancers. Nevertheless, the effects and the potential mechanisms of miR-665 in human LUSC are still unknown. Methods To analyse the clinical significant of miR-665 in human LUSC, quantitative real-time PCR (qRT-PCR) was use to measure miR-665 expression in LUSC specimen tissues and cell lines. Tripartite motif 8 (TRIM8) was verified a target of miR-665 by performing bioinformatic prediction and luciferase reporter assay. The expression levels of TRIM8 were examined through qRT-PCR and Western blotting in LUSC specimen tissues. CCK8 assay was fulfilled for analyzing the function in LUSC cell proliferation. Flow cytometry was used to detect cell and apoptosis. TRIM8 silencing and overexpression further verified the biological effects as those caused by miR-665. Results Here we reported that miR-665 expression was upregulated in LUSC specimen tissues and cell lines. High miR-665 levels were related to differentiation, tumor size and TNM stage. miR-665 mimics facilitated LUSC cell growth and cell cycle G1-S transition and repressed apoptosis. miR-665 inhibitor suppressed cell proliferation and G1-S transition and promoted apoptosis. miR-665 expression was negatively correlated with TRIM8 mRNA expression in LUSC. Luciferase reporter assay confirmed that TRIM8 was a direct target gene of miR-665. miR-665 mimics downregulated the TRIM8 levels, and miR-665 inhibitor upregulated the TRIM8 levels in LUSC cells. Particularly, silencing TRIM8 led to the similar effects of miR-665 mimics in LUSC cells. Overexpression of TRIM8 inhibited LUSC cell proliferation in vitro and in vivo. Furthermore, miR-665 promoted LUSC cell proliferation through facilitating the Wnt5a/β-catenin signaling pathway and restrained apoptosis via inhibiting Caspase-3 signaling pathway, whereas TRIM8 suppressed cell growth by repressing the Wnt5a/β-catenin signaling pathway and induced apoptosis through activating Caspase-3 signaling pathway. Conclusions The current study demonstrates that miR-665 facilitates LUSC cell proliferation and cell cycle transition by regulation of the Wnt5a/β-Catenin signaling pathway and represses cell apoptosis via modulation of Caspase-3 signaling pathway by directly targeting TRIM8. These findings suggest that miR-665 might be a potential new target for LUSC therapy.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 82-83
Author(s):  
Xiaoya Zhao ◽  
Qianru Hui ◽  
Paula Azevedo ◽  
Karmin O ◽  
Chengbo Yang

Abstract The calcium-sensing receptor (CaSR) is a pivotal regulator of calcium homeostasis. Our previous study has found that pig CaSR (pCaSR) is widely expressed in intestinal segments in weaned piglets. To characterize the activation of pCaSR by potential ligands and related cell signaling pathways, a dual-luciferase reporter assay was employed for the ligands screening and molecular docking was utilized to predict the binding mode of identified ligands. Our results showed that the dual-luciferase reporter assay system was well suited for pCaSR research and its ligand screening. The extracellular calcium activated pCaSR in a concentration-dependent manner with a half-maximal effective concentration (EC50) = 4.74 mM through the Gq/11 signaling pathway, EC50 = 2.85 mM through extracellular signal-regulated kinases 1 and 2 (ERK1/2) activation signaling pathway, and EC50 = 2.26 mM through the Ras homolog family member A (RhoA) activation signaling pathway. Moreover, the activation of pCaSR stimulated by extracellular calcium showed biased agonism through three main signaling pathways: ERK1/2 phosphorylation signaling, Gq/11 signaling, and G12/13 signaling. Both L-Tryptophan and α-casein (90–95) could activate the pCaSR in the presence of extracellular calcium. Furthermore, we characterized the L-tryptophan binding pocket formed by pCaSR residues TRP 70, SER 147, ALA168, SER 169, SER 170, ASP 190, GLU 297, ALA 298, and ILE 416, as well as the α-casein (90–95) binding pocket formed by pCaSR residues PRO188, ASN189, GLU191, HIS192, LYS225, LEU242, ASP480, VAL486, GLY487, VAL513, and TYR514. In conclusion, similar to the human CaSR, the pCaSR also shows biased agonism through three main signaling pathways and both α-casein (90–95) and L-tryptophan are agonists for pCaSR. Furthermore, the binding sites of α-casein (90–95) and L-tryptophan are mainly located within the extracellular domain of pCaSR.


2021 ◽  
Author(s):  
Jianli Ma ◽  
Wenhui Zhao ◽  
Han Zhang ◽  
Zhong Chu ◽  
Huili Liu ◽  
...  

Abstract BackgroundBreast cancer is the main cause of death among women worldwide. More and more long non-coding RNAs (lncRNAs) have been identified as oncogenes or tumor suppressors during cancer development. However, whether ANRIL is involved in drug resistance in triple-negative breast cancer (TNBC) has not been investigated. MethodsLuciferase reporter assay was conducted to verify the binding of miR-125a and ANRIL. RT-PCR and western blot were performed to detect the expression of miR-125a, ANRIL and ENO1. Gene silence and overexpression experiments as well as CCK-8 and colony formation assays on TNBC cell lines were performed to determine the regulation of molecular pathways. Glycolysis analysis was performed with Seahorse extracellular flux methodology. ResultsANRIL expression in TNBC patients and TNBC cells was examined and we found that ANRIL expression was upregulated in both TNBC patients and TNBC cell lines. Knockdown of ANRIL increased the cytotoxic effect of ADR and inhibited HIF-1α-dependent glycolysis in TNBC cells. In addition, we found that ANRIL negatively regulated miR-125a expression in TNBC cell lines. Besides, a dual-luciferase reporter assay proved ANRIL functioned as a sponger of miR-125a. Further investigation revealed that ENO1 was a target of miR-125a and positively regulated by ANRIL in TNBC cells. Additionally, ANRIL upregulation reversed miR-125-mediated inhibition on HIF-1α-dependent glycolysis in TNBC cells. More notably, 2-deoxy-glucose (2-DG) attenuated ANRIL-induced increase of drug resistance in TNBC cells. ConclusionsTaken together, our study was the first to identify that knockdown of ANRIL plays an active role in overcoming the drug resistance in TNBC by inhibiting glycolysis through the miR-125a/ENO1 pathway, which maybe serve useful for the development of novel therapeutic targets.


Author(s):  
Chunsheng Li ◽  
Jingrong Dong ◽  
Zhenqi Han ◽  
Kai Zhang

MicroRNAs (miRNAs) are reportedly involved in gastric cancer development and progression. In particular, miR-219-5p has been reported to be a tumor-associated miRNA in human cancer. However, the role of miR-219-5p in gastric cancer remains unclear. In this study, we investigated for the first time the potential role and underlying mechanism of miR-219-5p in the proliferation, migration, and invasion of human gastric cancer cells. miR-219-5p was found to be markedly decreased in gastric cancer tissues and cell lines compared with adjacent tissues and normal gastric epithelial cells. miR-219-5p mimics or anti-miR-219-5p was transfected into gastric cancer cell lines to overexpress or suppress miR-219-5p expression, respectively. Results showed that miR-219-5p overexpression significantly decreased the proliferation, migration, and invasion of gastric cancer cells. Conversely, miR-219-5p suppression demonstrated a completely opposite effect. Bioinformatics and luciferase reporter assays indicated that miR-219-5p targeted the 3′-untranslated region of the liver receptor homolog-1 (LRH-1), a well-characterized oncogene. Furthermore, miR-219-5p inhibited the mRNA and protein levels of LRH-1. LRH-1 mRNA expression was inversely correlated with miR-219-5p expression in gastric cancer tissues. miR-219-5p overexpression significantly decreased the Wnt/β-catenin signaling pathway in gastric cancer cells. Additionally, LRH-1 restoration can markedly reverse miR-219-5p-mediated tumor suppressive effects. Our study suggests that miR-219-5p regulated the proliferation, migration, and invasion of human gastric cancer cells by suppressing LRH-1. miR-219-5p may be a potential target for gastric cancer therapy.


2021 ◽  
Author(s):  
Lu Jiang ◽  
Yan Zhang ◽  
Linghui Guo ◽  
Chaoyang Liu ◽  
Weihong Ren

Abstract Background: RNA cargo in exosomes,especially microRNAs (miRNAs), play an important role in the chemotherapy drug resistance of human cancers. However, the role and mechanism of exosomal miR-107 on multidrug resistance of gastric cancer cells was still not clear. In this study, we sought to explore whether exosomal miR-107 could reverse theresistance of gastric cancer cells to the chemotherapy drugs. Methods: We extracted exosomes from sensitive (SGC-7901, MGC-803) and resistant (SGC-7901/5-FU) gastric cancer cells by ultracentrifugation and the isolated exosomes were identified using transmission electron microscopy (TEM) and dynamic light scattering analysis (DLS). The expression of miR-107 and high mobility group A2 (HMGA2) were detected by real-time quantitative PCR (RT-qPCR). MTT assay was used to investigate the effect of exosomes on gastric cancer cells growth in vitro. The uptake of exosomes by recipient cells were observed using a fluorescence microscope. The predicted target relationship between miR-107 and HMGA2 was verified by gauss-luciferase reporter assay. The expression of HMGA2, p-mTOR/mTOR, P-gp and other exosomal indicated marker proteins were detected by western blot. Results: Our results indicated that the isolated exosomes were demostrated typically cup-like lipid bilayer membrans structure. SGC-7901/5-FU cells were cross-resistant to chemotherapy drug cisplatin (DDP), and the sensitive cells-secreted exosomes drastically reversed the resistance of the resistant gastric cells to the chemotherapeutic drugs,which was verificated by exosomal inhibitor GW4896. Mechanistically, the reversal effect were mainly mediated by exosome-secreted miR-107 through downregulating the expression of targert molecular HMGA2, and inhibiting HMGA2/mTOR/P-gp pathway, which were proofed by luciferase reporter assay and rescue assay. Conclusions: These findings demonstrated that exosome-transmitted miR-107 significantly enhanced the sensitivity of resistant gastric cancer cells to chemotherapeutic agents by mediating the HMGA2/mTOR/P-gp axis and appling exosomal miR-107 may be a novel target in gastric cancers treatment.


2020 ◽  
Author(s):  
Pengcheng Li ◽  
Junhui Xing ◽  
Jianwu Jiang ◽  
Xinyu Tian ◽  
Xuemeng Liu ◽  
...  

Abstract Background: Nasopharyngeal carcinoma (NPC) is the most common malignant tumor in the head and neck that is characterized by high local malignant invasion and distant metastasis. miR-18a-5p reportedly plays an important role in tumorigenesis and development. However, little is known about the mechanism underlying miR-18a-5p’s role in NPC.Methods:Quantitative real-time PCR was used to detect the expression of miR-18a-5p in NPC tissues and cell lines. MTT assay and plate clone formation assay were used to detect the effect of miR-18a-5p on NPC cell proliferation. Woundhealing assays and Transwell assays were used to detect the effect of miR-18a-5p on NPC cell invasion and migration. The expressions of epithelialmesenchymal transition (EMT)-related proteins N-cadherin, Vimentin, and E-cadherin were detected by Westernblot. Bioinformatics and dual-luciferase reporter assay were used to detect the targeting interaction between miR-18a-5p and SMAD2. Xenotransplantation and metastasis model were used to detect the effect of miR-18a-5p on NPC growth and metastasis in vivo.Results:miR-18a-5p was highly expressed in NPC tissues and cell lines. Overexpression of miR-18a-5p promotedNPC cell proliferation, invasion, migration, and EMT process, whereas inhibition of miR-18a-5p expression led to the oppositeresults. Results of dual-luciferase reporter assay showed that SMAD2 was the target gene of miR-18a-5p, and SMAD2 could reverse the effect of miR-18a-5p on NPC cell line. Xenotransplantation and metastasis model experiments in nude mice showed that miR-18a-5p promotesNPC growth and metastasis in vivo.Conclusions:Targeting SMAD2 downregulated miR-18a-5p expression, thereby promoting NPC cell proliferation, invasion, migration, and EMT.


2020 ◽  
Vol 19 (4) ◽  
pp. 691-698
Author(s):  
Lin I-Ju ◽  
Tian YongJie

Purpose: The purpose of this study was to evaluate the role of miR-624-5p in ovarian cancer.Methods: MiR-624-5p expression in ovarian cancer {OC) cell lines and normal cells (NCs) was evaluated and compared the differential miR-624-5p in OC A2780 cells and cisplatin-resistant OC cell line (A2780/DDP). CCK-8 was used to evaluate changes in cell viability of the A2780 and A2780/DDP cell lines as well as silenced miR-624-5p. Western Blot examined the Stat3 and phosphorylated Pi3k. The binding between PDGFRA and miR-624-5p was predicted on Targetscan and verified through Luciferase Reporter Assay. The role of PDGFRA in A2780/DDP by overexpressing PDGFRA was evaluated by RT-qPCR and CCK-8 assays. RT-qPCR assay also measured miR-624-5p expression responsive to different dosages of cisplatin and CCK8 examined viability levels correspondingly. In addition, the interplay of PDGFRA and miR-624-5p by combined downregulation of both miR-624-5pand PDGFRA were evaluated.Results: OC cells had higher miR-624-5p expression than NCs but lower compared to cisplatinresistant A2780/DDP cells. A2780/DDP cells had higher viability than OC cell line A2780. Stat3 and phosphorylated PI3K were activated in A2780/DDP cells. Silencing miR-624-5p led to lower viability inA2780/DDP cells. miR-624-5p expression dropped as the cisplatin concentration increased, resulting in decreasing viability respectively. Luciferase Reporter assay validated the binding of miR-624-5p and PDGFRA in A2780/DDP cells. Overexpressed PDGFRA induced lower cell viability in A2780/DDP cells. Downregulation of PDGFRA partially restored the lowered viability and inhibited Stat3 as well as phosphorylated Pi3k induced by miR-624-5p inhibitor.Conclusion: MiR-624-5p could add to the cellular resistance to cisplatin in OC in-vitro model, which indicated that it might help unveil the mystery of drug-resistance in clinical stage of ovarian cancer. Keywords: MiR-624-5p, resistance, cisplatin, PDGFRA/Stat3/PI3K, ovarian cancer


2018 ◽  
Vol 51 (2) ◽  
pp. 909-923 ◽  
Author(s):  
Hao Sun ◽  
Zhiyu Huang ◽  
Peihui Wu ◽  
Zongkun Chang ◽  
Weiming  Liao ◽  
...  

Background/Aims: Cyclin-dependent kinase 6 (CDK6) regulates inflammatory response and cell differentiation. This study sought to determine whether CDK6 and miR-320c co-regulate chondrogenesis and inflammation. Methods: Utilizing quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC), CDK6 and miR-320c expression were assessed in a micromass culture of human bone mesenchymal stem cells that underwent chondrogenesis in vitro as well as in chondrocytes from E16.5 mouse forelimbs. Normal chondrocytes were transfected with miR-320c mimic, miR-320c inhibitor, or CDK6-siRNA. Luciferase reporter assay results confirmed that miR-320c directly targets CDK6 by interacting with the 3′-untranslated region (3′-UTR) of its mRNA. qRT-PCR, Western blotting, and Cell Counting Kit-8 were subsequently used to evaluate the effects of miR-320c overexpression and CDK6 inhibition on inflammatory factor expression, as well as to investigate the effects of NF-kB and MAPK signaling pathway activation on IL-1β-induced chondrocyte inflammation. Results: Our results show that miR-320c expression increased during the middle stage and decreased during the late stage of hBMSC chondrogenic differentiation. In contrast, CDK6 expression decreased during the middle stage and increased during the late stage of hBMSC chondrogenic differentiation. Moreover, CDK6 expression increased in severe OA cartilage and in hypertrophic chondrocytes of mouse forelimbs at E16.5. Results of the luciferase reporter assay showed that miR-320c modulated CDK6 expression by binding to the 3′-UTR of its mRNA. miR-320c overexpression and CDK6 inhibition repressed IL-1β-induced expression of inflammatory factors and regulated the NF-kB signaling pathway. Conclusion: CDK6 and miR-320c co-regulate hBMSC chondrogenesis and IL-1β-induced chondrocyte inflammation through the NF-kB signaling pathway, suggesting that miR-320c and CDK6 inhibitors can be used to repress catabolism in human chondrocytes.


2020 ◽  
Vol 21 (3) ◽  
pp. 195-207 ◽  
Author(s):  
Wei Chen ◽  
Jingjie Du ◽  
Xiaodi Li ◽  
Ziming Zhi ◽  
Songshan Jiang

Aim: miR-137 is downregulated in various cancers; however, its function in ovarian cancer remains unclear. Methods: The roles of miR-137 in apoptosis were accessed through IC50 values and DAPI assay. The regulation of MCL1 by miR-137 was investigated through luciferase reporter assay and immunoblot. Results: miR-137 mimic could decrease the IC50 value of cisplatin and promote apoptosis in OVCAR3 ovarian cancer cells. Using luciferase assay, results on a panel of anti-apoptotic proteins, we identified MCL1 as a target for miR-137 and the results were confirmed using immunoblot. Finally, the underlying pathway in which miR-137 may be involved was investigated by transcriptome sequencing. Conclusion: These results suggest that miR-137 downregulates MCL1 in ovarian cancer cells and mediates cisplatin-induced apoptosis.


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