scholarly journals A tumor-associated splice-isoform ofMAP2K7drives dedifferentiation in MBNL1-low cancers via JNK activation

2020 ◽  
Vol 117 (28) ◽  
pp. 16391-16400 ◽  
Author(s):  
Debleena Ray ◽  
Yu Chye Yun ◽  
Muhammad Idris ◽  
Shanshan Cheng ◽  
Arnoud Boot ◽  
...  

Master splicing regulator MBNL1 shapes large transcriptomic changes that drive cellular differentiation during development. Here we demonstrate that MBNL1 is a suppressor of tumor dedifferentiation. We surveyedMBNL1expression in matched tumor/normal pairs across The Cancer Genome Atlas and found thatMBNL1was down-regulated in several common cancers. Down-regulation ofMBNL1predicted poor overall survival in breast, lung, and stomach adenocarcinomas and increased relapse and distant metastasis in triple-negative breast cancer. Down-regulation of MBNL1 led to increased tumorigenic and stem/progenitor-like properties in vitro and in vivo. A discrete set of alternative splicing events (ASEs) are shared betweenMBNL1-low cancers and embryonic stem cells including aMAP2K7∆exon2 splice variant that leads to increased stem/progenitor-like properties via JNK activation. Accordingly, JNK inhibition is capable of reversingMAP2K7∆exon2-driven tumor dedifferentiation in MBNL1-low cancer cells. Our work elucidates an alternative-splicing mechanism that drives tumor dedifferentiation and identifies biomarkers that predict enhanced susceptibility to JNK inhibition.

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chengwu Xiao ◽  
Wei Zhang ◽  
Meimian Hua ◽  
Huan Chen ◽  
Bin Yang ◽  
...  

Abstract Background The tripartite motif (TRIM) family proteins exhibit oncogenic roles in various cancers. The roles of TRIM27, a member of the TRIM super family, in renal cell carcinoma (RCC) remained unexplored. In the current study, we aimed to investigate the clinical impact and roles of TRIM27 in the development of RCC. Methods The mRNA levels of TRIM27 and Kaplan–Meier survival of RCC were analyzed from The Cancer Genome Atlas database. Real-time PCR and Western blotting were used to measure the mRNA and protein levels of TRIM27 both in vivo and in vitro. siRNA and TRIM27 were exogenously overexpressed in RCC cell lines to manipulate TRIM27 expression. Results We discovered that TRIM27 was elevated in RCC patients, and the expression of TRIM27 was closely correlated with poor prognosis. The loss of function and gain of function results illustrated that TRIM27 promotes cell proliferation and inhibits apoptosis in RCC cell lines. Furthermore, TRIM27 expression was positively associated with NF-κB expression in patients with RCC. Blocking the activity of NF-κB attenuated the TRIM27-mediated enhancement of proliferation and inhibition of apoptosis. TRIM27 directly interacted with Iκbα, an inhibitor of NF-κB, to promote its ubiquitination, and the inhibitory effects of TRIM27 on Iκbα led to NF-κB activation. Conclusions Our results suggest that TRIM27 exhibits an oncogenic role in RCC by regulating NF-κB signaling. TRIM27 serves as a specific prognostic indicator for RCC, and strategies targeting the suppression of TRIM27 function may shed light on future therapeutic approaches.


Oncogene ◽  
2021 ◽  
Author(s):  
Yong Wu ◽  
Qinhao Guo ◽  
Xingzhu Ju ◽  
Zhixiang Hu ◽  
Lingfang Xia ◽  
...  

AbstractNumerous studies suggest an important role for copy number alterations (CNAs) in cancer progression. However, CNAs of long intergenic noncoding RNAs (lincRNAs) in ovarian cancer (OC) and their potential functions have not been fully investigated. Here, based on analysis of The Cancer Genome Atlas (TCGA) database, we identified in this study an oncogenic lincRNA termed LINC00662 that exhibited a significant correlation between its CNA and its increased expression. LINC00662 overexpression is highly associated with malignant features in OC patients and is a prognostic indicator. LINC00662 significantly promotes OC cell proliferation and metastasis in vitro and in vivo. Mechanistically, LINC00662 is stabilized by heterogeneous nuclear ribonucleoprotein H1 (HNRNPH1). Moreover, LINC00662 exerts oncogenic effects by interacting with glucose-regulated protein 78 (GRP78) and preventing its ubiquitination in OC cells, leading to activation of the oncogenic p38 MAPK signaling pathway. Taken together, our results define an oncogenic role for LINC00662 in OC progression mediated via GRP78/p38 signaling, with potential implications regarding therapeutic targets for OC.


2021 ◽  
Author(s):  
Qingqing Hu ◽  
Xiaochu Hu ◽  
Yalei Zhao ◽  
Lingjian Zhang ◽  
Ya Yang ◽  
...  

Abstract Background: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Shugoshin-like protein 2 (SGOL2) is a centromeric protein that ensures the correct and orderly process of mitosis by protecting and maintaining centripetal adhesions during meiosis and mitosis. However, the role of SGOL2 in cancer is not well understood. Methods: The mRNA and protein levels of SGOL2 and survival analysis were conducted in The Cancer Genome Atlas (TCGA) and further validated in 2 independent cohorts. Differential genes correlated with SGOL2 and mitotic arrest deficient 2 like 1 (MAD2) were obtained using LinkedOmics. Subsequently, loss-of-function and rescue assays were carried out in vitro and in vivo to assess the functions of SGOL2 in hepatic tumorigenisis. Findings: We found that SGOL2 was significantly overexpressed in HCC and predicted unfavorable overall survival in HCC patients. Next, we identified 47 differentially expressed genes positively correlated with both SGOL2 and MAD2 to be mainly involved in the cell cycle. In addition, SGOL2 downregulation suppressed the migration, invasion, proliferation, stemness and EMT of HCC cells and inhibited tumorigenesis in vivo. Furthermore, SGOL2 promoted tumor proliferation by activating MAD2-induced cell cycle dysregulation, which could be reversed by the MAD2 inhibitor M2I-1. We also proved that SGOL2 activated MAD2 by directly binding with MAD2. Conclusions: The results of this study showed that SGOL2 acts as an oncogene in HCC cells by directly activating MAD2 and then dysregulating the cell cycle, thereby providing a potential target for HCC patients in the future.


2019 ◽  
Vol 133 (2) ◽  
pp. 367-379 ◽  
Author(s):  
Jing Chen ◽  
Di Wu ◽  
Yue Zhang ◽  
Yong Yang ◽  
Yunfei Duan ◽  
...  

Abstract Long non-coding RNAs (lncRNAs) play important roles in a variety of tumours; however, their biological function and clinical significance in hepatocellular carcinoma (HCC) are still unclear. In the present study, the clinical significance, biological function and regulatory mechanisms of lncRNA DCST1-AS1 in HCC were investigated. Differential lncRNAs in HCC were identified based on The Cancer Genome Atlas (TCGA) database. The biological function and mechanism of DCST1-AS1 were studied in vitro and in vivo. LncRNA DCST1-AS1 was highly expressed in HCC tissues, and the high expression of DCST1-AS1 was significantly correlated with larger tumours and shorter survival time. Moreover, DCST1-AS1 knockout significantly inhibited proliferation, promoted apoptosis and cycle arrest of HCC cells, and inhibited tumour growth in vivo. According to functional analysis, DCST1-AS1 competitively bound miR-1254, thus blocking the silencing effect of miR-1254 on the target gene Fas apoptosis inhibitor 2 (FAIM2). A novel lncRNA DCST1-AS1 that functions as an oncogene in HCC was discovered. DCST1-AS1 up-regulates the expression of FAIM2 by up-regulating the expression of miR-1254, ultimately promoting the proliferation of HCC cells. This research provides new therapeutic targets for HCC.


2020 ◽  
Vol 16 (25) ◽  
pp. 1921-1930
Author(s):  
Zhou Xu ◽  
Lin Zhuang ◽  
Xiaoyin Wang ◽  
Qianrong Li ◽  
Yan Sang ◽  
...  

Aim: To explore FBXW7 protein-coding transcript isoform (α, β and γ) expression, their functions and prognostic value in ovarian serous cystadenocarcinoma (OSC). Materials & methods: FBXW7 transcript data were collected from The Cancer Genome Atlas and the Genotype-Tissue Expression project. IOSE, A2780 and SKOV3 cells were used for in vitro and in vivo studies. Results: FBXW7α and FBXW7γ are dominant protein-coding transcripts that were downregulated in OSC. FBXW7γ overexpression reduced the protein expression of c-Myc, Notch1 and Yap1 and suppressed OSC cell growth in vitro and in vivo. FBXW7γ expression was an independent indicator of longer disease-specific survival (HR: 0.588; 95% CI: 0.449–0.770) and progression-free survival (HR: 0.708; 95% CI: 0.562–0.892). Conclusion: FBXW7γ is a tumor-suppressive and might be the only prognosis-related FBXW7 transcript in OSC.


2020 ◽  
Author(s):  
Guangyan Kan ◽  
Ziyang Wang ◽  
Chunjie Sheng ◽  
Chen Yao ◽  
Yizhi Mao ◽  
...  

Abstract BackgroundLung cancer is one the most widely spread cancers in the world and half of the non-small cell lung cancers are lung adenocarcinoma (LUAD). Although there were several drugs been approved for LUAD therapy, a large portion of LUAD still can not be successfully treated due to lack of available therapeutic targets. Here, we investigated the oncogenic roles of DKC1 in LUAD and explored the potential mechanism and the possibility for LUAD therapy. MethodsWe analyzed Gene Expression Omnibus (GEO) and The Cancer Genome Atlas Program (TCGA) database and tissue microarray of LUAD. The expression of DKC1 and its correlation with prognosis were examined. In addition, Loss- and gain-of-function assays were used for oncogenic function of DKC1 both in vitro and in vivo.ResultsDKC1 is overexpressed in LUAD compared with normal tissues. High expression of DKC1 predicts the poor overall survival. Knockdown DKC1 in LUAD cell lines induced G1 phase arrest and inhibits cell proliferation. Ectopic expression of DKC1 could rescue the growth of LUAD cell lines. The abundance of DKC1 is positively correlated with TERC and TERT levels. DKC1 downregulation caused decreased TERC expression, reduced telomerase activity and shorten telomere, and thus eventually led to cell senescence and apoptosis.ConclusionsOur results show that high DKC1 expression indicates poor prognosis and DKC1 downregulation could induce telomere-related cell senescence and apoptosis. This study suggests that DKC1 could serve as a candidate diagnostic biomarker and therapeutic target for LUAD.


2020 ◽  
Author(s):  
Gang Zhao ◽  
Jun Jia ◽  
Lansheng Wang ◽  
Yongkang Zhang ◽  
Han Yang ◽  
...  

Abstract Background:Postoperative recurrence is the main reason of poor clinical consequences in glioma patients, so preventing recurrence of tumors is crucial in management of gliomas. Methods:In this study, the expression of matrix metalloproteinases (MMPs)in tissues from normal were detected by using RNA-seq analysis.Glioma cases from the public databases (The Cancer Genome Atlas (TCGA), The Chinese Glioma Genome Atlas(CGGA), Betastasis) were included in this study.The hydrogelcontains minocycline (Mino) and vorinostat (Vor)(G/Mino + Vor) was formed under 365 nm when photoinitiator was added in. High Performance Liquid Chromatography (HPLC) assay was used to assessed the release of drugs in G/Mino + Vor hydrogel. MTT assay was used to explore the biosecurity of GelMA. Immunohistochemistry assay, ELISA assay, Tunel assay were used to demonstrate the antitumor effect of G/Mino + Vor hydrogel.Results:We developed G/Mino + Vor hydrogel successfully. Thenthe experiment in vitro and in vivo confirmed MMPs-responsive delivery of minocycline and vorinostat in hydrogel and the anti-glioma effect on incomplete tumor operation model, which indicated that G/Mino + Vor hydrogel effectively inhibited the recurrence of glioma after surgery.Conclusions: In summary, G/Mino + Vor hydrogel could continuous release minocycline and vorinostat in surgical cavity for inhibiting local recurrence of glioma after operation.


2021 ◽  
Vol 18 (5) ◽  
pp. 1041-1047
Author(s):  
Yan Dong ◽  
Qing Xu ◽  
Xi Jia ◽  
Chao Li ◽  
Dan Xu ◽  
...  

Purpose: To investigate the effect of thiamine triethylorthoformate conjugate (TTO) on Parkinson disease (PD) in vitro and in vivo in a mice model. Methods: The effect of TTO on behavioural changes in PD mouse model was studied using pole, traction and swimming tests. Astrocyte proliferation after TTO treatment was assessed using 3 (4, 5 dimethyl 2 thi¬azolyl) 2, 5 diphenyl 2 H tetrazolium bromide (MTT) assay. Apoptosis was determined with flow cytometry using Annexin V Fluorescein isothiocyanate kit. Results: Treatment of PD mice with TTO led to a decrease in climbing time, increase in suspension score and enhancement of swimming score, when compared to the untreated group (p < 0.05). Treatment of astrocytes with TTO prior to MPP incubation significantly increased proliferation (p < 0.05). Apoptosis induction in astrocytes by MPP was attenuated by pre-treatment with TTO. Pre-treatment of astrocytes with 10 µM TTO markedly reduced JNK activation, when compared to astrocytes incubated with MPP alone (p < 0.05). Up-regulation of Bax and down-regulation of Bcl 2 by MPP in astrocytes were attenuated by pre-treatment with TTO. MPP-induced up-regulation of cleaved caspase 3 was suppressed in astrocytes by TTO pre-treatment (p < 0.05). Conclusion: Treatment with TTO prevents MPP+ -induced neuronal damage in vitro in astrocytes and in vivo in mice. The neuro-protective effect of TTO involves down-regulation of JNK activation, inhibition of caspase-3 level, decrease in Bax and increase in Bcl-2 expression. Thus, TTO has a potential for use in the treatment of Parkinson’s disease.


2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi192-vi192
Author(s):  
Jie Li ◽  
Jianfang Ning ◽  
Tomoyuki Koga ◽  
Ming Li ◽  
Shan Zhu ◽  
...  

Abstract INTRODUCTION Lactate dehydrogenase A (LDHA) encodes an enzyme that catalyzes the inter-conversion between pyruvate and lactate in glycolysis. Here, we demonstrate that LDHA mediates a novel role in DNA repair independent of this metabolic function. METHODS siRNA screen, The Cancer Genome Atlas (TCGA) survival analysis, ionizing radiation (IR), g-H2AX, and chromatin assays, site-directed mutagenesis. RESULTS In an orthogonal siRNA-informatic screen to identify genes 1) when silenced caused IR sensitivity in patient-derived glioblastoma lines and 2) lowered expression is associated with improved survival in TCGA, LDHA surfaced as the top candidate. The survival association was validated by LDHA immunohistochemical staining in an independent collection of glioblastoma samples. In vitro and in vivo, silencing of LDHA sensitized glioblastoma lines to IR and enhanced radiation-induced g-H2AX accumulation. Such sensitization was not observed after treatment with an LDHA inhibitor, suggesting the metabolic function of LDHA is distinct from its role in DNA repair. Supporting this hypothesis, truncation mutations that suppressed the LDHA glycolysis function minimally affected its role in DNA repair. Mechanistically, cytoplasmic LDHA translocates into the nucleus in response to IR. This translocation was associated with subsequent chromatin transition into an open conformation and enhanced homologous recombination. CONCLUSION The novel LDHA function in DNA repair suggests intricate crosstalks between glycolytic metabolism and DNA repair, offering a new platform for glioblastoma therapeutic development.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jacqueline M. Grible ◽  
Patricija Zot ◽  
Amy L. Olex ◽  
Shannon E. Hedrick ◽  
J. Chuck Harrell ◽  
...  

AbstractThe hormone prolactin (PRL) and its receptor (hPRLr) are significantly involved in breast cancer pathogenesis. The intermediate hPRLr (hPRLrI) is an alternatively-spliced isoform, capable of stimulating cellular viability and proliferation. An analogous truncated mouse PRLr (mPRLr) was recently found to be oncogenic when co-expressed with wild-type mPRLr. The goal of this study was to determine if a similar transforming event occurs with the hPRLr in human breast epithelial cells and to better understand the mechanism behind such transformation. hPRLrL+I co-expression in MCF10AT cells resulted in robust in vivo and in vitro transformation, while hPRLrI knock-down in MCF7 cells significantly decreased in vitro malignant potential. hPRLrL+I heterodimers displayed greater stability than hPRLrL homodimers, and while being capable of activating Jak2, Ras, and MAPK, they were unable to induce Stat5a tyrosine phosphorylation. Both immunohistochemical breast cancer tissue microarray data and RNA sequencing analyses using The Cancer Genome Atlas (TCGA) identified that higher hPRLrI expression associates with triple-negative breast cancer. These studies indicate the hPRLrI, when expressed alongside hPRLrL, participates in mammary transformation, and represents a novel oncogenic mechanism.


Sign in / Sign up

Export Citation Format

Share Document