Alternative Splicing in Normal Development and in Breast Cancer.

1995 ◽  
Author(s):  
John R. Bermingham
BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Pihua Han ◽  
Jingjun Zhu ◽  
Guang Feng ◽  
Zizhang Wang ◽  
Yanni Ding

Abstract Background Breast cancer (BRCA) is one of the most common cancers worldwide. Abnormal alternative splicing (AS) frequently observed in cancers. This study aims to demonstrate AS events and signatures that might serve as prognostic indicators for BRCA. Methods Original data for all seven types of splice events were obtained from TCGA SpliceSeq database. RNA-seq and clinical data of BRCA cohorts were downloaded from TCGA database. Survival-associated AS events in BRCA were analyzed by univariate COX proportional hazards regression model. Prognostic signatures were constructed for prognosis prediction in patients with BRCA based on survival-associated AS events. Pearson correlation analysis was performed to measure the correlation between the expression of splicing factors (SFs) and the percent spliced in (PSI) values of AS events. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were conducted to demonstrate pathways in which survival-associated AS event is enriched. Results A total of 45,421 AS events in 21,232 genes were identified. Among them, 1121 AS events in 931 genes significantly correlated with survival for BRCA. The established AS prognostic signatures of seven types could accurately predict BRCA prognosis. The comprehensive AS signature could serve as independent prognostic factor for BRCA. A SF-AS regulatory network was therefore established based on the correlation between the expression levels of SFs and PSI values of AS events. Conclusions This study revealed survival-associated AS events and signatures that may help predict the survival outcomes of patients with BRCA. Additionally, the constructed SF-AS networks in BRCA can reveal the underlying regulatory mechanisms in BRCA.


2009 ◽  
Vol 69 (5) ◽  
pp. 2082-2090 ◽  
Author(s):  
Marc Hirschfeld ◽  
Axel zur Hausen ◽  
Herta Bettendorf ◽  
Markus Jäger ◽  
Elmar Stickeler

2020 ◽  
Author(s):  
Yvonne L. Chao ◽  
Yinzhou Zhu ◽  
Hannah J. Wiedner ◽  
Yi-Hsuan Tsai ◽  
Lily Wilkinson ◽  
...  

AbstractSmall nucleolar RNAs (snoRNAs) have long been considered “housekeeping genes”, important for ribosomal biogenesis and protein synthesis. However, there is increasing evidence that this largely ignored class of non-coding RNAs (ncRNAs) also have wide-ranging, non-canonical functions in diseases, including cancer. SnoRNAs have been shown to have both oncogenic and tumor suppressor roles, yet whether snoRNAs regulate metastasis is unknown. Here we show that expression of certain snoRNAs are enriched in lymph node (LN) metastases in a micro-surgical, immune-competent mouse model of breast cancer. We identify the snoRNA Snord67 as a key regulator of LN metastasis. Knockout of Snord67 resulted in significantly decreased LN tumor growth and subsequent development of distant metastases. This was associated with loss of targeted 2’-O-methylation on the small nuclear RNA U6, a component of the spliceosome. RNA sequencing revealed distinct alternative splicing patterns in Snord67 knockout cells. Using rapid autopsy breast cancer cases, we found that matched human primary tumor and LN metastases revealed similar alternatively spliced genes, including several that are known to contribute to cancer. These results demonstrate that Snord67 is critical for growth of LN metastases and subsequent spread to distant metastases, and suggest that snoRNA-guided modifications of the spliceosome represent a previously unappreciated, yet targetable pathway in cancer.


2002 ◽  
Vol 10 (3) ◽  
pp. 164-165
Author(s):  
Natasa Todorovic-Rakovic ◽  
Vesna Ivanovic ◽  
Miroslav Demajo ◽  
Borka Neskovic ◽  
Zora Neskovic-Konstantinovic ◽  
...  

TGF-beta1 is a pluripotent cytokine with diverse effects in the normal development of mammary glands, and in the development of malignant tumors of the breast. The aim of the study was to determine the levels of TGF-beta1 in the group of advanced breast cancer, in which increased TGF-beta1 levels were most likely to be expected. TGF-beta1 levels were also compared with estradiol levels. Our results suggested that TGF-beta1 synthesis may be regulated by estrogen or anti-estrogen through ER. Finding of increased TGF-beta1 levels, due to its possible role in predicting invasive phenotype in later phases of tumor progression, may indicate the tendency of tumor tissue towards autonomy.


2014 ◽  
Vol 28 (11) ◽  
pp. 1191-1203 ◽  
Author(s):  
Y. Xu ◽  
X. D. Gao ◽  
J.-H. Lee ◽  
H. Huang ◽  
H. Tan ◽  
...  

2012 ◽  
Vol 19 (4) ◽  
pp. 509-526 ◽  
Author(s):  
Dennis H Dowhan ◽  
Matthew J Harrison ◽  
Natalie A Eriksson ◽  
Peter Bailey ◽  
Michael A Pearen ◽  
...  

Protein arginine methyltransferase-6 (PRMT6) regulates steroid-dependent transcription and alternative splicing and is implicated in endocrine system development and function, cell death, cell cycle, gene expression and cancer. Despite its role in these processes, little is known about its function and cellular targets in breast cancer. To identify novel gene targets regulated by PRMT6 in breast cancer cells, we used a combination of small interfering RNA and exon-specific microarray profilingin vitrocoupled toin vivovalidation in normal breast and primary human breast tumours. This approach, which allows the examination of genome-wide changes in individual exon usage and total transcript levels, demonstrated thatPRMT6knockdown significantly affected i) the transcription of 159 genes and ii) alternate splicing of 449 genes. ThePRMT6-dependent transcriptional and alternative splicing targets identifiedin vitrowere validated in human breast tumours. Using the list of genes differentially expressed between normal andPRMT6knockdown cells, we generated aPRMT6-dependent gene expression signature that provides an indication of PRMT6 dysfunction in breast cancer cells. Interrogation of several well-studied breast cancer microarray expression datasets with thePRMT6gene expression signature demonstrated that PRMT6 dysfunction is associated with better overall relapse-free and distant metastasis-free survival in the oestrogen receptor (ER (ESR1)) breast cancer subgroup. These results suggest that dysregulation ofPRMT6-dependent transcription and alternative splicing may be involved in breast cancer pathophysiology and the molecular consequences identifying a unique and informative biomarker profile.


2013 ◽  
Vol 12 (1) ◽  
pp. 75 ◽  
Author(s):  
Ifeoma Ubby ◽  
Erica Bussani ◽  
Antonio Colonna ◽  
Giuseppe Stacul ◽  
Martina Locatelli ◽  
...  

2010 ◽  
Vol 24 (5) ◽  
pp. 914-922 ◽  
Author(s):  
Kazufumi Ohshiro ◽  
Prakriti Mudvari ◽  
Qing-chang Meng ◽  
Suresh K. Rayala ◽  
Aysegul A. Sahin ◽  
...  

Abstract Alternative splicing of precursor mRNA is a fundamental mechanism to generate multiple proteins from a single gene. Although constitutive and alternative mRNA splicing is temporally and spatially regulated, deregulation of mRNA splicing could cause development, progression, and metastasis of tumors. Through yeast two-hybrid screening of a human breast cDNA library using estrogen receptor-α (ERα) as bait, we identified a novel nuclear receptor box containing full-length protein, nuclear protein E3-3 (NPE3-3). Our results revealed that NPE3-3 associates with not only ERα but also with splicing factors, serine/arginine-rich protein (SRp)-30c, SRp40, and splicing factor SC-35, suggesting that NPE3-3 is likely to be involved in regulation of mRNA splicing. Accordingly, transient expression of NPE3-3 in cells resulted in expected splicing of the CD44 control minigene. We also discovered that NPE3-3-overexpressing clones produced a novel, previously unrecognized, alternatively spliced variant of ERα (termed ERαV), which had a molecular size of 37 kDa composed of only exons 1, 2, 7, and 8. ERαV was expressed and sequestered in the cytoplasm in MCF-7 cells stably overexpressing NPE3-3, suggesting its involvement in nongenomic hormone signaling. NPE3-3 clones exhibited up-regulation of ERK1/2 signaling, cyclin D1, and cathepsin D and enhanced tumor cell proliferation, migration, and tumorigenicity. Moreover, direct expression of the ERαV in breast cancer cells stimulated ERK1/2 up-regulation and cyclin D1 expression. We found that ERαV physically interacted with MAPK kinase (MEK)-1/2, and thus, an ERαV and MEK1/2 complex could lead to the activation of the ERK1/2 pathway. Interestingly, NPE3-3 was up-regulated in human breast tumors. These findings revealed a role for NPE3-3 in alternative splicing and suggest that ERα is a physiological target of NPE3-3, leading to a constitutive nongenomic signaling pathway in breast cancer cells.


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