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He J, Yang X, Zhang C, Li A, Wang W, Xing J, E J, Xu X, Wang H, Yu E, Shi D, Wang H. CNN2 silencing inhibits colorectal cancer development through promoting ubiquitination of EGR1. Life Sci Alliance 2023; 6:e202201639. [PMID: 37188478 PMCID: PMC10185810 DOI: 10.26508/lsa.202201639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/17/2023] Open
Abstract
Colorectal cancer (CRC) is one of the most commonly diagnosed malignant tumors of the digestive tract. H2-calponin (CNN2), an actin cytoskeleton-binding protein, is an isoform of the calponin protein family whose role in CRC is still unknown. Research based on clinical samples showed the up-regulation of CNN2 in CRC and its association with tumor development, metastasis, and poor prognosis of patients. Both in vitro loss-of-function and gain-of-function experiments showed that CNN2 participates in CRC development through influencing malignant cell phenotypes. In vivo, xenografts formed by CNN2 knockdown cells also showed a slower growth rate and smaller final tumors. Furthermore, EGR1 was identified as a downstream of CNN2, forming a complex with CNN2 and YAP1 and playing an essential role in the CNN2-induced regulation of CRC development. Mechanistically, CNN2 knockdown down-regulated EGR1 expression through enhancing its ubiquitination, thus decreasing its protein stability in a YAP1-dependent manner. In summary, CNN2 plays an EGR1-dependent promotion role in the development and progression of CRC, which may be a promising therapeutic target for CRC treatment.
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Affiliation(s)
- Jinghu He
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Xiaohong Yang
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Chuansen Zhang
- Department of Anatomy, Naval Medical University, Shanghai, China
| | - Ang Li
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Wei Wang
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Junjie Xing
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Jifu E
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Xiaodong Xu
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Hao Wang
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Enda Yu
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
| | - Debing Shi
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Hantao Wang
- Department of General Surgery, Changhai HospitalAffiliated to Navy Medical University, Shanghai, China
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Tong D, Yuan J, Wang Z, Yu E, E J. USP37 promotes angiogenesis and metastasis in colorectal cancer by facilitating β-catenin stability. Am J Cancer Res 2023; 13:2323-2341. [PMID: 37424824 PMCID: PMC10326571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 03/09/2023] [Indexed: 07/11/2023] Open
Abstract
Ubiquitin-specific peptidase 37 (USP37) is a novel deubiquitinating enzyme, which has been found to be involved in the progression of multiple tumors. However, its function in colorectal cancer (CRC) remains unclear. Here, we firstly proved that USP37 was up-regulated in CRC cases, and high USP37 expression predicted poor survival of CRC cases. USP37 up-regulation promoted the proliferation, cell cycle progression, apoptosis inhibition, migration, invasion, epithelial mesenchymal transition (EMT) and stemness of CRC cells; moreover, USP37 facilitated the angiogenesis of human umbilical vein endothelial cells (HUVECs). However, USP37 silencing showed the opposite function. In vivo experiment suggested that USP37 silencing suppressed the growth and lung metastasis of CRC in nude mice. Interestingly, we found that CTNNB1 (gene coding for β-catenin) level was positively correlated with USP37 level in CRC and USP37 silencing suppressed the expression of β-catenin in CRC cells and xenograft tumor tissues. Further mechanistic studies showed that USP37 could enhance the stability of β-catenin by inhibiting its ubiquitination. Taken together, USP37 acts as an oncogene in CRC, which promotes angiogenesis, metastasis and stemness by enhancing β-catenin stability via inhibiting its ubiquitination. USP37 may be a usefully target in CRC clinical treatment.
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Affiliation(s)
- Dafeng Tong
- Department of Colorectal Surgery, Changhai Hospital, Navy Military Medical UniversityShanghai, China
| | - Jie Yuan
- Department of Colorectal Surgery, Changhai Hospital, Navy Military Medical UniversityShanghai, China
- Department of Rehabilitation, Beidaihe Rehabilitation and Recuperation Center for PLA Joint Logistics Support ForceQinhuangdao, Hebei, China
| | - Zhaoming Wang
- Department of Colorectal Surgery, Changhai Hospital, Navy Military Medical UniversityShanghai, China
| | - Enda Yu
- Department of Colorectal Surgery, Changhai Hospital, Navy Military Medical UniversityShanghai, China
| | - Jifu E
- Department of Colorectal Surgery, Changhai Hospital, Navy Military Medical UniversityShanghai, China
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E J, Kang Z, Yuan J, Wang Z, Tong D, Xing J. ZNF516 suppresses stem cell-like characteristics by regulating the transcription of Sox2 in colorectal cancer. Am J Cancer Res 2022; 12:3745-3759. [PMID: 36119845 PMCID: PMC9442021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023] Open
Abstract
This study aimed to explore the biological function and the molecular mechanism of the action of zinc-finger protein 516 (ZNF516) in suppressing stem cell-like characteristics and tumor progression in colorectal cancer (CRC). The expression profiles of ZNF516 in clinical samples and from The Cancer Genome Atlas (TCGA) CRC database were analyzed. Cell transfection was used to overexpress and knockdown ZNF516 in CRC cells. Cell counting kit-8 (CCK8) assays, transwell assays and flow cytometry were used to study cell proliferation, invasion and stem cell-like characteristics, respectively. Cycloheximide (CHX) was used to examine the effect of ZNF516 expression on Sox2 degradation. Finally, the effects of ZNF516 on tumor growth and metastasis were tested on xenograft tumor models and lung metastasis models in immunocompromised mice. We found that the expression level of ZNF516 was lower in TCGA CRC tissue and clinical CRC samples compared with that in normal colorectal mucosal cells. Overexpression of ZNF516 in CRC cells inhibited cell proliferation, colony formation, migration and invasion, whereas ZNF516 knockdown showed the opposite effects. In addition, ZNF516 overexpression inhibited the sphere-forming ability of CRC cells and suppressed the expression of CD133, CD44 and Oct4 in CRC cells. ZNF516 decreased the stability of Sox2 through a mechanism mediated by EGFR. By in vivo experiments using mouse tumor models, we further confirmed that ZNF516 attenuated tumor growth and alleviated lung metastasis in mice. In conclusion, ZNF516 functions as a tumor suppressor by regulating the transcription of Sox2 to inhibit cell proliferation, invasion, and the development of stem cell-like characteristics in CRC cells.
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Affiliation(s)
- Jifu E
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical UniversityShanghai, China
| | - Zhengchun Kang
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical UniversityShanghai, China
| | - Jie Yuan
- Department of Rehabilitation, Beidaihe Rehabilitation and Recuperation Center for PLA Joint Logistics Support ForceQinhuangdao, China
| | - Zhaoming Wang
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical UniversityShanghai, China
| | - Dafeng Tong
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical UniversityShanghai, China
| | - Junjie Xing
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical UniversityShanghai, China
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Abstract
Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Long non-coding RNAs (lncRNAs) have been increasingly reported to serve vital parts in malignancies including CRC. Although cancer susceptibility 21 (CASC21) has been uncovered to play a part in CRC, its mechanism still needs further explanation. Thus, our study aimed to further explore the influence and mechanism of CASC21 in CRC progression. Quantitative real-time RT-PCR and western blot were performed to detect gene expression; a series of functional assays were performed to investigate the effect of CASC21 on CRC cells; in vivo tumour growth was evaluated via the nude mice xenograft model. The results revealed that CASC21 facilitated CRC cell proliferation, migration, epithelial-mesenchymal transition (EMT) and stemness. In addition, CASC21 was co-expressed with and bound to transcription factor POU5F1B (POU class 5 homeobox 1B). CASC21 recruited POU5F1B to HGH1 promoter to activate the transcription of HGH1 homolog. Also, CASC21 served as a competitive endogenous RNA (ceRNA) to up-regulate HGH1 via endogenously sponging miR-485-5p. Moreover, HGH1 overexpression counteracted the suppression of CASC21 deficiency on CRC tumour growth. In summary, our study indicated that CASC21 enhanced the expression of HGH1 to promote the malignancy of CRC by recruiting POU5F1B and sponging miR-485-5p, suggesting a key role of CASC21 in CRC progression.
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Affiliation(s)
- Chenxin Zhang
- Department of General Surgery, The 983th Hospital of Joint Logistic Support Force of PLA, Tianjin, China.,Department of Colorectal Surgery, Changhai Hospital, Naval Medical University, Shanghai, China
| | - Jifu E
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical University, Shanghai, China
| | - Enda Yu
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical University, Shanghai, China
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Xing J, Li X, E J, Wang C, Wang H. Inverse relationship between CD40L expression and cytolytic molecule expression by CD8 +CXCR5 + T follicular cytotoxic cells in colorectal cancer. Exp Cell Res 2020; 389:111892. [PMID: 32035135 DOI: 10.1016/j.yexcr.2020.111892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/20/2020] [Accepted: 02/04/2020] [Indexed: 10/25/2022]
Abstract
CXCR5+ CD8 T cells, sometimes termed T follicular cytotoxic (Tfc) cells, are characterized by high proinflammatory cytokine and cytolytic molecule expression and low exhaustion and checkpoint molecule expression. Additionally, Tfc cells could promote B cell responses and support Ig release. It is yet unclear how Tfc cells could help B cells when they have the potential to mediate cytotoxicity at the same time. In this study, we found that Tfc cells expressed significantly higher levels of CD40L than non-Tfc CD8 T cells. Interestingly, Tfc cells from colorectal cancer (CRC) patients presented significantly higher CD40L than Tfc cells from healthy controls in a manner that was associated with CRC stage. Coincubation of Tfc cells and autologous B cells resulted in higher CD40L expression in a time-dependent manner. Interestingly, activated Tfc cells, when incubated with B cells, presented rapid downregulation of perforin and granzyme B. In general, greater than 50% of tumor-infiltrating Tfc cells expressed CD40L. In addition, the level of CD40L in tumor-infiltrating Tfc cells was higher in stage IV CRC patients than in stage II and stage III CRC patients. Interestingly, the levels of perforin and granzyme B expression by tumor-infiltrating Tfc cells were inversely correlated with the level of CD40L expression by tumor-infiltrating Tfc cells. Overall, we demonstrated that an inverse association existed between CD40L and cytotoxic molecule expression in Tfc cells from CRC patients.
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Affiliation(s)
- Junjie Xing
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
| | - Xu Li
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Jifu E
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Chen Wang
- Department of Oncology, Ruijin North Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Hao Wang
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
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Kang Z, Jifu E, Guo K, Ma X, Zhang Y, Yu E. Knockdown of long non-coding RNA TINCR decreases radioresistance in colorectal cancer cells. Pathol Res Pract 2019; 215:152622. [PMID: 31540772 DOI: 10.1016/j.prp.2019.152622] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 08/21/2019] [Accepted: 09/01/2019] [Indexed: 12/13/2022]
Abstract
An increasing number of studies have revealed the role of long non-coding RNAs in cancer. However, the mechanisms of action and functional utility in colorectal cancer (CRC) have not been fully elucidated. Here we describe the functional role and potential mechanism of TINCR (terminal differentiation-induced non-coding RNA) in CRC. Firstly, TINCR was selected using sequencing analyses and the starBase database. Cell Counting Kit-8, scratch wound healing, and transwell assays revealed that TINCR inhibited proliferation and migration in SW620 and HTC116 cells. Intriguingly, TINCR expression was up-regulated in a radioresistant CRC cell line (SW620R). Although TINCR had no significant effects on SW620R cell proliferation or migration, knockdown of TINCR reduced the radioresistance, and its overexpression had opposite effects. We then focused on transcription factor 4 (TCF4) as it is downregulated in CRC and associated with increased stemness in tumors. We found that TINCR and TCF4 levels were positively related in SW620R cells. TINCR knockdown reduced sphere formation ability in SW620R cells. TINCR also suppressed the OCT4 and SOX2 stemness genes, despite having no effect on NANOG. The expression levels of these genes were substantially higher in SW620R than in SW620 cells. To further explore the mechanism of TINCR and radioresistance, miR-137 was analyzed as it targets TCF4. We firstly confirmed that TCF4 is a target of miR-137. We then identified that TINCR knockdown enhanced miR-137 expression in SW620R cells. Collectively, these findings suggest that TINCR knockdown inhibits TCF4 by regulating miR-137 expression.
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Affiliation(s)
- Zhengchun Kang
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical University, Shanghai, 200433, China
| | - E Jifu
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical University, Shanghai, 200433, China
| | - Kai Guo
- Department of Gastroenterology, The 161th Hospital of PLA, Wuhan, Hubei, 430010, China
| | - Xiuzhu Ma
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical University, Shanghai, 200433, China
| | - Yingyi Zhang
- Department of Oncology, Changhai Hospital, Naval Medical University, Shanghai, 200433, China.
| | - Enda Yu
- Department of Colorectal Surgery, Changhai Hospital, Naval Medical University, Shanghai, 200433, China.
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E J, Yan F, Kang Z, Zhu L, Xing J, Yu E. CD8 +CXCR5 + T cells in tumor-draining lymph nodes are highly activated and predict better prognosis in colorectal cancer. Hum Immunol 2018; 79:446-452. [PMID: 29544815 DOI: 10.1016/j.humimm.2018.03.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 02/14/2018] [Accepted: 03/09/2018] [Indexed: 01/04/2023]
Abstract
Tumor-draining lymph nodes (TDLNs) are the primary sites of tumor antigen presentation, as well as the origin of metastasis in most cases. Hence, the type and function of immune cells in TDLNs are critical to the microenvironment and potentially affect the clinical outcome of the malignancy. CD8+CXCR5+ T cells are recently described to present high effector functions in infectious diseases, but their role in colorectal cancer (CRC) remains unclear. In forty-four Stage III CRC patients, we examined the CD8+CXCR5+ T cells in blood, tumor, and TDLN. CD8+CXCR5+ T cells represented lass than 2% of CD3+ T cells in blood, but a much larger population in tumor. In TDLN, the CD8+CXCR5+ T cells represented the vast majority of CD8+ T cells and between 9.3% and 32.9% of CD3+ T cells. The prevalence of CD8+CXCR5+ T cells in tumor was not associated with their frequency in peripheral blood, but was positively correlated with their frequency in TDLN. The transcription of effector genes, including IFNG, TNF, IL2, PRF1, and GZMB, and exhaustion markers, including PD1, TIM3, 2B4, and LAG3, were examined in CD8+CXCR5+ T cells and CD8+CXCR5- T cells. With a few exceptions, CD8+CXCR5+ T cell presented significantly higher effector gene expression, and significantly lower exhaustion marker expression than their CXCR5- counterparts. In addition, the prognosis of CRC patients was positively associated with the frequency of TDLN CD8+CXCR5+ T cells, and with the expression of IFNG, PRF1, and GZMB expression by tumor and TDLN CD8+CXCR5+ T cells. Together, these results demonstrated that CD8+CXCR5+ T cells were significant participants of CRC-associated immunity and could potentially serve as therapeutic options.
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Affiliation(s)
- Jifu E
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Feihu Yan
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Zhengchun Kang
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Liangliang Zhu
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Junjie Xing
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
| | - Enda Yu
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
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Wang H, Cao F, Li X, Miao H, E J, Xing J, Fu CG. miR-320b suppresses cell proliferation by targeting c-Myc in human colorectal cancer cells. BMC Cancer 2015; 15:748. [PMID: 26487644 PMCID: PMC4617986 DOI: 10.1186/s12885-015-1728-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 10/08/2015] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND MicroRNAs (miRNAs) are small noncoding RNAs that potentially play a critical role in tumorigenesis. Mounting evidence indicates that one specific miRNA: miR-320b is down regulated in numerous human cancers, including colorectal cancer (CRC); making the hypothesis that miR-320b may play a key role in tumorigenesis plausible. However, its role in carcinogenesis remains poorly defined. The goal of this study is to better clarify the role of miR-320b in tumor growth of CRC. METHODS Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was conducted to detect the expression of miR-320b in CRC tissues and 5 CRC cell lines. The effect of miR-320b on cell proliferation was analyzed in vitro and in vivo. Furthermore, a luciferase reporter assay was performed to measure the target effects of miR-320b. Lastly, the messenger RNA (mRNA) and protein levels of the gene c-MYC were measured in CRC cell lines and tissues by qRT-PCR, and confirmed via Western blot and Immunohistochemical (IHC) staining. RESULTS The results presented here showed that miR-320b expression was down regulated in both CRC tissues and cells. Overexpression of miR-320b in CRC cells was statistically correlated with a decrease of cell growth in vitro and in vivo, while c-MYC was identified as a target gene of miR-320b in CRC. Furthermore, it was found that up-regulation of c-Myc can attenuate the effects induced by miR-320b. CONCLUSIONS Our identification of c-MYC as a target gene of miR-320b provides new insights into the pathophysiology of CRC proliferation, and identifies miR-320b as a novel therapeutic target for the treatment of CRC.
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Affiliation(s)
- Hantao Wang
- Department of Colorectal Surgery, Changhai Hospital, Shanghai, 200433, China.
| | - Fuao Cao
- Department of Colorectal Surgery, Changhai Hospital, Shanghai, 200433, China.
| | - Xu Li
- Department of Colorectal Surgery, Changhai Hospital, Shanghai, 200433, China.
| | - Hua Miao
- Department of General Surgery, The First People's Hospital of Pinghu, Pinghu, 314200, Zhejiang Province, China.
| | - Jifu E
- Department of Colorectal Surgery, Changhai Hospital, Shanghai, 200433, China.
| | - Junjie Xing
- Department of Colorectal Surgery, Changhai Hospital, Shanghai, 200433, China.
| | - Chuan-Gang Fu
- Department of Colorectal Surgery, Changhai Hospital, Shanghai, 200433, China.
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E J, Xing J, Gong H, He J, Zhang W. Combine MEK inhibition with PI3K/mTOR inhibition exert inhibitory tumor growth effect on KRAS and PIK3CA mutation CRC xenografts due to reduced expression of VEGF and matrix metallopeptidase-9. Tumour Biol 2014; 36:1091-7. [PMID: 25326806 DOI: 10.1007/s13277-014-2667-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 09/19/2014] [Indexed: 01/04/2023] Open
Abstract
Although epidermal growth factor receptor (EGFR) monoclonal antibody (mAb) cetuximab are used widely to treat KRAS wild-type metastatic colorectal cancer (mCRC), patients become resistant by various mechanisms, including KRAS, BRAF, and PIK3CA mutations, thereafter relapsing. AZD6244 is a potent, selective, and orally available MEK1/2 inhibitor. In this study, we investigated the mechanisms of AZD6244 alone or with BEZ235, an orally available potent inhibitor of phosphatidylinositol 3-kinase (PI3K) and mammalian target of rapamycin (mTOR), in a KRAS and PIK3CA mutation CRC xenograft model. HCT116 (KRAS (G13D) , PIK3CA (H1047R) mutant) cells were subcutaneously injected into the nude mice. Mice were randomly assigned to treatment with vehicle, cetuximab, AZD6244, BEZ235, or AZD6244 plus BEZ235, for up to 3 weeks; then, all mice were sacrificed, and tumor tissues were subjected to Western blot analysis and immunohistochemical staining. AZD6244 or BEZ235 slightly inhibit tumor growth of HCT116 xenografts, and the combination treatment markedly enhanced their antitumor effects. However, cetuximab had no effect on tumor growth. Western blot analysis and immunohistochemical staining revealed that treatment with AZD6244 or BEZ235 could significantly reduce the phosphorylation level of ERK1/2 or AKT in HCT116 tumor tissues. More interesting, the antiangiogenic effects were substantially enhanced when the agents were combined which may due to the reduced expression of VEGF and matrix metallopeptidase-9 (MMP-9) in tumor tissues. These results suggest that the combination of a selective MEK inhibitor and a PI3K/mTOR inhibitor was effective in CRC harboring with KRAS and PIK3CA mutations. The mechanisms of synergistic antitumor effects may be due to antiangiogenesis.
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Affiliation(s)
- Jifu E
- Department of Colorectal Surgery, Changhai Hospital, Second Military Medical University, Changhai Road 168, Shanghai, 200433, China
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