Role Of Alternative Splicing Research Articles

The role of alternative splicing and splicing factors in diabetes: Current status and future perspectives

AbstractWith glucose being at the center of energy consumption and production, maintaining homeostasis of this simple sugar is of pivotal importance. Loss of glucose homeostasis results in altered blood glucose levels, that are frequently observed in type 2 diabetes (T2D) and obesity. T2D and obesity share pathophysiological mechanisms and genetic backgrounds. These conditions collectively impact over 500 million individuals worldwide, necessitating a deeper mechanistic understanding for effective therapeutic strategies. Recent studies have highlighted the involvement of abnormal alternative splicing (AS) and changes in splicing factors (SFs) in the development and progression of diabetic conditions, presenting AS and SFs as promising targets for therapy. This review focuses on the deregulation of AS (INSR, TCF7L2, and mTOR) and SF (Sam68) deregulation in diabetic conditions. In addition, we discuss the importance of mTOR signaling in diabetic conditions and its regulation by AS and SFs. Furthermore, we discuss current strategies aimed at targeting AS and SFs. Finally, we discuss research challenges, and unresolved questions in the field, and offer recommendations to enhance our comprehension of the significance of AS and SFs in the context of diabetes and obesity.This article is categorized under: RNA Processing > Splicing Mechanisms RNA Processing > Splicing Regulation/Alternative Splicing RNA in Disease and Development > RNA in Disease

PTBP1 as a potential regulator of disease.

Polypyrimidine tract-binding protein 1 (PTBP1) is a member of the heterogeneous nuclear ribonucleoprotein (hnRNP) family, which plays a key role in alternative splicing of precursor mRNA and RNA metabolism. PTBP1 is universally expressed in various tissues and binds to multiple downstream transcripts to interfere with physiological and pathological processes such as the tumor growth, body metabolism, cardiovascular homeostasis, and central nervous system damage, showing great prospects in many fields. The function of PTBP1 involves the regulation and interaction of various upstream molecules, including circular RNAs (circRNAs), microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). These regulatory systems are inseparable from the development and treatment of diseases. Here, we review the latest knowledge regarding the structure and molecular functions of PTBP1 and summarize its functions and mechanisms of PTBP1 in various diseases, including controversial studies. Furthermore, we recommend future studies on PTBP1 and discuss the prospects of targeting PTBP1 in new clinical therapeutic approaches.

CCAR-1 works together with the U2AF large subunit UAF-1 to regulate alternative splicing

ABSTRACT The Cell Division Cycle and Apoptosis Regulator (CCAR) protein family members have recently emerged as regulators of alternative splicing and transcription, as well as having other key physiological functions. For example, mammalian CCAR2/DBC1 forms a complex with the zinc factor protein ZNF326 to integrate alternative splicing with RNA polymerase II transcriptional elongation in AT-rich regions of the DNA. Additionally, Caenorhabditis elegans CCAR-1, a homolog to mammalian CCAR2, facilitates the alternative splicing of the perlecan unc-52 gene. However, much about the CCAR family’s role in alternative splicing is unknown. Here, we have examined the role of CCAR-1 in genome-wide alternative splicing in Caenorhabditis elegans and have identified new alternative splicing targets of CCAR-1 using RNA sequencing. Also, we found that CCAR-1 interacts with the spliceosome factors UAF-1 and UAF-2 using mass spectrometry, and that knockdown of ccar-1 affects alternative splicing patterns, motility, and proteostasis of UAF-1 mutant worms. Collectively, we demonstrate the role of CCAR-1 in regulating global alternative splicing in C. elegans and in conjunction with UAF-1.

Alternative splicing in breast cancer

Alternative splicing allows a gene to produce multiple proteins and is the main source of human proteome diversity. Aberrant regulation of alternative splicing produces proteins with different structures and can lead to altered protein function, inactivation, or deleterious variants, which can have severe effects on normal cellular function, leading to many diseases, including cancer. Alternative splicing abnormalities are often found in diseases, so alternative splicing is highly correlated with diseases and treatment. According to relevant statistics, breast cancer is an important factor that threatens women’s lives and health. A common sign of tumors in humans is abnormal alternative splicing. An increasing amount of evidence shows that abnormal alternative splicing plays an important role in the occurrence and development of breast cancer. At the same time, in the related treatment of breast cancer, alternative splicing can lead to the failure of existing treatment methods and induce drug resistance. Currently, targeted therapy is still the key strategy for breast cancer treatment. In this review, we discuss the five classifications of alternative splicing and aberrant alternative splicing in breast cancer. The role of alternative splicing in the drug resistance of breast cancer is also discussed. Evidence has shown that aberrant alternative splicing can lead to drug resistance to current therapies. Because splicing factors are involved in many aspects of cancer, splicing factors may provide a new strategy for cancer treatment and a powerful tool for progress in the fight against breast cancer. Antisense oligonucleotides form a double-stranded structure by complementary pairing with mRNA, which prevents the binding of mRNA and ribosomes, thus inhibiting protein synthesis. Therefore, after finding effective targets, antisense oligonucleotides can be applied in gene therapy, drug research and development, biological research, and other fields to improve therapeutic effects.

Alternative Splicing under Cold Stress in Paper Mulberry

The paper mulberry is a commonly found tree species with a long history of cultivation. It also serves as a crucial case study for understanding how woody plants adapt to low temperatures. Under cold treatment, we observed a substantial number of alternative splicing (AS) genes, showcasing the intricate landscape of AS events. We have detected all seven types of AS events, with the alternative 3′ splice site (A3) having the most. We observed that many genes that underwent differential AS were significantly enriched in starch and sucrose metabolism and circadian rhythm pathways. Moreover, a considerable proportion of differentially spliced genes (DSGs) also showed differential expression, with 20.38% and 25.65% under 12 h and 24 h cold treatments, respectively. This suggests a coordinated regulation between gene AS and expression, playing a pivotal role in the paper mulberry’s adaptation to cold stress. We further investigated the regulatory mechanisms of AS, identifying 41 serine/arginine-rich (SR) splicing factors, among which 11 showed differential expression under cold treatment, while 29 underwent alternative splicing. Additionally, genes undergoing AS displayed significantly higher DNA methylation levels under cold stress, while normal splicing (non-AS) genes exhibited relatively lower methylation levels. These findings suggest that methylation may play an important role in governing gene AS. Finally, our research will provide useful information on the role of AS in the cold acclimation tolerance of the paper mulberry.

Regulation of Epithelial-Mesenchymal Transitions by Alternative Splicing: Potential New Area for Cancer Therapeutics.

The epithelial-mesenchymal transition (EMT) is a complicated biological process in which cells with epithelial phenotype are transformed into mesenchymal cells with loss of cell polarity and cell-cell adhesion and gain of the ability to migrate. EMT and the reverse mesenchymal-epithelial transitions (METs) are present during cancer progression and metastasis. Using the dynamic switch between EMT and MET, tumour cells can migrate to neighbouring organs or metastasize in the distance and develop resistance to traditional chemotherapy and targeted drug treatments. Growing evidence shows that reversing or inhibiting EMT may be an advantageous approach for suppressing the migration of tumour cells or distant metastasis. Among different levels of modulation of EMT, alternative splicing (AS) plays an important role. An in-depth understanding of the role of AS and EMT in cancer is not only helpful to better understand the occurrence and regulation of EMT in cancer progression, but also may provide new therapeutic strategies. This review will present and discuss various splice variants and splicing factors that have been shown to play a crucial role in EMT.

SRSF2 is required for mRNA splicing during spermatogenesis

BackgroundRNA splicing plays significant roles in fundamental biological activities. However, our knowledge about the roles of alternative splicing and underlying mechanisms during spermatogenesis is limited.ResultsHere, we report that Serine/arginine-rich splicing factor 2 (SRSF2), also known as SC35, plays critical roles in alternative splicing and male reproduction. Male germ cell-specific deletion of Srsf2 by Stra8-Cre caused complete infertility and defective spermatogenesis. Further analyses revealed that deletion of Srsf2 disrupted differentiation and meiosis initiation of spermatogonia. Mechanistically, by combining RNA-seq data with LACE-seq data, we showed that SRSF2 regulatory networks play critical roles in several major events including reproductive development, spermatogenesis, meiotic cell cycle, synapse organization, DNA recombination, chromosome segregation, and male sex differentiation. Furthermore, SRSF2 affected expression and alternative splicing of Stra8, Stag3 and Atr encoding critical factors for spermatogenesis in a direct manner.ConclusionsTaken together, our results demonstrate that SRSF2 has important functions in spermatogenesis and male fertility by regulating alternative splicing.

Alternative splicing in Atlantic salmon head kidney and SHK-1 cell line during the Piscirickettsia salmonis infection: A comparative transcriptome survey

Piscirickettsia salmonis, an intracellular bacterium in salmon aquaculture, is a big challenge because it is responsible for 54.2% of Atlantic salmon mortalities. In recent years, the high relevance of Alternative Splicing (AS) as a molecular mechanism associated with infectious conditions and host-pathogen interaction processes, especially in host immune activation, has been observed. Several studies have highlighted the role of AS in the host's immune response during viral, bacterial, and endoparasite infection. In the present study, we evaluated AS transcriptome profiles during P. salmonis infection in the two most used study models, SHK-1 cell line and salmon head kidney tissue. First, the SHK-1 cell line was exposed to P. salmonis infection at 0-, 7-, and 14-days post-infection (dpi). Following, total RNA was extracted for Illumina sequencing.On the other hand, RNA-Seq datasets of Atlantic salmon head kidney infected with the same P. salmonis strayingwase used. For both study models, the highest number of differentially alternative splicing (DAS) events was observed at 7 dpi, 16,830 DAS events derived from 9213 DAS genes in SHK-1 cells, and 13,820 DAS events from 7684 DAS genes in salmon HK. Alternative first exon (AF) was the most abundant AS type in the three infection times analyzed, representing 31% in SHK-1 cells and 228.6 in salmon HK; meanwhile, mutually exclusive exon (MX) was the least abundant. Notably, functional annotation of DAS genes in SHK-1 cells infected with P. salmonis showed a high presence of genes related to nucleotide metabolism. In contrast, the salmon head kidney exhibited many GO terms associated with immune response. Our findings reported the role of AS during P. salmonis infection in Atlantic salmon. These studies would contribute to a better understanding of the molecular bases that support the pathogen-host interaction, evidencing the contribution of AS regulating the transcriptional host response.

Comparative transcriptome profiling reveals RNA splicing alterations and biological function in patients exposed to occupational noise.

Genetic factors play an important role in susceptibility to noise-induced hearing loss (NIHL). Alternative splicing (AS) is an essential mechanism affecting gene expression associated with disease pathogenesis at the post-transcriptional level, but has rarely been studied in NIHL. To explore the role of AS in the development of NIHL, we performed a comprehensive analysis of RNA splicing alterations by comparing the RNA-seq data from blood samples from NIHL patients and subjects with normal hearing who were exposed to the same noise environment. A total of 356 differentially expressed genes, including 23 transcription factors, were identified between the two groups. Of particular note was the identification of 56 aberrant alternative splicing events generated by 41 differentially expressed genes between the two groups, with exon skipping events accounting for 54% of all the differentially alternative splicing (DAS) events. The results of functional enrichment analysis showed that these intersecting DAS genes and differentially expressed genes were significantly enriched in autophagy and mitochondria-related pathways. Together, our findings provide insights into the role of AS events in susceptibility and pathogenesis of NIHL.

A serpin gene from a parasitoid wasp disrupts host immunity and exhibits adaptive alternative splicing.

Alternative splicing (AS) is a major source of protein diversity in eukaryotes, but less is known about its evolution compared to gene duplication (GD). How AS and GD interact is also largely understudied. By constructing the evolutionary trajectory of the serpin gene PpSerpin-1 (Pteromalus puparum serpin 1) in parasitoids and other insects, we found that both AS and GD jointly contribute to serpin protein diversity. These two processes are negatively correlated and show divergent features in both protein and regulatory sequences. Parasitoid wasps exhibit higher numbers of serpin protein/domains than nonparasitoids, resulting from more GD but less AS in parasitoids. The potential roles of AS and GD in the evolution of parasitoid host-effector genes are discussed. Furthermore, we find that PpSerpin-1 shows an exon expansion of AS compared to other parasitoids, and that several isoforms are involved in the wasp immune response, have been recruited to both wasp venom and larval saliva, and suppress host immunity. Overall, our study provides an example of how a parasitoid serpin gene adapts to parasitism through AS, and sheds light on the differential features of AS and GD in the evolution of insect serpins and their associations with the parasitic life strategy.

Targeting alternative splicing in cancer immunotherapy.

Tumor immunotherapy has made great progress in cancer treatment but still faces several challenges, such as a limited number of targetable antigens and varying responses among patients. Alternative splicing (AS) is an essential process for the maturation of nearly all mammalian mRNAs. Recent studies show that AS contributes to expanding cancer-specific antigens and modulating immunogenicity, making it a promising solution to the above challenges. The organoid technology preserves the individual immune microenvironment and reduces the time/economic costs of the experiment model, facilitating the development of splicing-based immunotherapy. Here, we summarize three critical roles of AS in immunotherapy: resources for generating neoantigens, targets for immune-therapeutic modulation, and biomarkers to guide immunotherapy options. Subsequently, we highlight the benefits of adopting organoids to develop AS-based immunotherapies. Finally, we discuss the current challenges in studying AS-based immunotherapy in terms of existing bioinformatics algorithms and biological technologies.

Abstract P3018: SCARNA20 Promotes M2 Macrophage Polarization Under Endotoxemia And Reduces Inflammation

Background: Macrophage polarization plays a key role in the inflammatory process. M1 pro-inflammatory and M2 anti-inflammatory phenotypes can down-regulate each other and may contribute to the pathogenesis of various diseases. Small Cajal Body Associated RNAs (SCARNAs) play a key role in alternative splicing and maturation of mRNAs. Our recent studies found that a combination of Procainamide (P, DNMT1 inhibitor) and Tubastatin A (T, HDAC6 inhibitor) reduces inflammation upon lipopolysaccharide (LPS) stimuli. Hypothesis: We hypothesize that the P+T treatment increases the expression of SCARNA20 hence reducing the proinflammatory response and promoting M2 macrophage polarization after LPS challenge. Methods and Results: To elucidate SCARNAs of interest during the inflammatory response, we treated macrophages with LPS (1μg/mL) and P (400nM/mL) + T (2.5μM/mL) for 1hr and performed RNA sequencing. Based on the sequencing results and qRT-PCR validation, SCARNA20 was the most significantly differentially expressed SCARNA between conditions (Fig. A) . The expression of TNFα was significantly reduced with the P+T treatment (Fig. B) . SCARNA20 overexpression (OE) showed an increase in the expression of the M2 marker CD163 and a reduction in the expression of the M1 marker CD80 (Fig. C) . Additionally, TNFα expression was significantly reduced in the SCARNA20 OE samples after the LPS challenge without treatment with P+T (Fig. D) . Finally, SCARNA20 knockdown macrophages (Fig. E) treated with P+T did not suppress TNFα expression (Fig. F) . Conclusions: We report for the first time that SCARNA20 is an important regulator of M2 macrophage polarization and pro-inflammatory response.

Alternative Splicing during Fiber Development in G. hirsutum.

Cotton is a valuable cash crop in many countries. Cotton fiber is a trichome that develops from a single epidermal cell and serves as an excellent model for understanding cell differentiation and other life processes. Alternative splicing (AS) of genes is a common post-transcriptional regulatory process in plants that is essential for plant growth and development. The process of AS during cotton fiber formation, on the other hand, is mainly unknown. A substantial number of multi-exon genes were discovered to be alternatively spliced during cotton fiber formation in this study, accounting for 23.31% of the total number of genes in Gossypium hirsutum. Retention intron (RI) is not necessarily the most common AS type, indicating that AS genes and processes during fiber development are very temporal and tissue-specific. When compared to fiber samples, AS is more prevalent at the fiber initiation stages and in the ovule, indicating that development stages and tissues use different AS strategies. Genes involved in fiber development have gone through stage-specific AS, demonstrating that AS regulates cotton fiber development. Furthermore, AS can be regulated by trans-regulation elements such as splicing factor and cis-regulation elements such as gene length, exon numbers, and GC content, particularly at exon-intron junction sites. Our findings also suggest that increased DNA methylation may aid in the efficiency of AS, and that gene body methylation is key in AS control. Finally, our research will provide useful information about the roles of AS during the cotton fiber development process.

The role of alternative splicing in lung cancer.

Aberrant alternative splicing (AS) events are frequently observed in lung cancer, which can be attributed to aberrant gene AS, alterations in splicing regulatory factors, or changes in splicing regulatory mechanisms. Consequently, the dysregulation of alternative RNA splicing is the fundamental cause of lung cancer. In this review, we have summarized the pivotal role of AS in the development, progression, invasion, metastasis, angiogenesis, and drug resistance of lung cancer. Ultimately, this review emphasizes the potential of AS as biomarkers in lung cancer prognosis and diagnosis, and introduces some applications of AS isoform in the treatment of lung cancer. The comprehension of the AS may provide a glimmer of hope for the eradication of lung cancer.

#6118 ALTERNATIVE SPLICING IN MECHANICALLY STRETCHED PODOCYTES AS A MODEL OF GLOMERULAR HYPERTENSION

Abstract Background and Aims It has been shown that mRNA splicing plays a relevant role in disease pathophysiology. However, the possible role of alternative splicing (AS) in hypertensive nephropathy (HN) has not been investigated. The purpose of the Sys_CARE (Systems Medicine Investigation of AS in Cardiac and Renal Diseases) project is to investigate the possible implication of AS events in HN development and progression. Method Differentiated murine podocytes were seeded on a flexible silicone membrane, and mechanically stretched using the Stretchy apparatus (NIPOKA GmbH, Greifswald). Cells were stretched for 3 days under low and high stretch conditions with a frequency of 0.5 Hz. The mRNA and proteins were isolated and analyzed using RNA_Seq and LC-MS/MS techniques. Enrichment analysis identified proteins which were classified according to the related biological processes, molecular function and cellular components. Splicing and transcript expression were evaluated with bioinformatical tools (rMATS, leafcutter, Whippet, MAJIQ, IsoformSwitchAnalyzeR). Results Proteomic analysis of cultured podocytes revealed significant different expression levels for 135 proteins (54 increased and 81 decreased) and 424 proteins (195 increased and 229 decreased) under low and high stretch conditions, respectively, compared to unstretched conditions. Interestingly, most of the proteins with decreased intensity upon stretch are cytoskeleton and actin-binding proteins. In contrast, the up-regulated proteins are more associated in clusters affecting mRNA processing and splicing. By RNA_Seq we identified over 1000 different splicing events including all types of alternative splicing events. We screened for candidates that showed an alternative splicing event in multiple tools, were found in the proteomics, were podocyte-specific, or showed altered expression in glomerulopathies such as diabetic nephropathy. In this regard, we found an isoform switch of Myl6 and Shroom3 after mechanical stretch. Conclusion Using mechanically stretched podocytes as a model of HN, we found significant up- and down-regulated proteins. In addition, by RNA_Seq we identified an isoform switch of Myl6 and Shroom3 that might be essential for the development of HN.

Splicing complexity as a pivotal feature of alternative exons in mammalian species

BackgroundAs a significant process of post-transcriptional gene expression regulation in eukaryotic cells, alternative splicing (AS) of exons greatly contributes to the complexity of the transcriptome and indirectly enriches the protein repertoires. A large number of studies have focused on the splicing inclusion of alternative exons and have revealed the roles of AS in organ development and maturation. Notably, AS takes place through a change in the relative abundance of the transcript isoforms produced by a single gene, meaning that exons can have complex splicing patterns. However, the commonly used percent spliced-in (Ψ) values only define the usage rate of exons, but lose information about the complexity of exons’ linkage pattern. To date, the extent and functional consequence of splicing complexity of alternative exons in development and evolution is poorly understood.ResultsBy comparing splicing complexity of exons in six tissues (brain, cerebellum, heart, liver, kidney, and testis) from six mammalian species (human, chimpanzee, gorilla, macaque, mouse, opossum) and an outgroup species (chicken), we revealed that exons with high splicing complexity are prevalent in mammals and are closely related to features of genes. Using traditional machine learning and deep learning methods, we found that the splicing complexity of exons can be moderately predicted with features derived from exons, among which length of flanking exons and splicing strength of downstream/upstream splice sites are top predictors. Comparative analysis among human, chimpanzee, gorilla, macaque, and mouse revealed that, alternative exons tend to evolve to an increased level of splicing complexity and higher tissue specificity in splicing complexity. During organ development, not only developmentally regulated exons, but also 10–15% of non-developmentally regulated exons show dynamic splicing complexity.ConclusionsOur analysis revealed that splicing complexity is an important metric to characterize the splicing dynamics of alternative exons during the development and evolution of mammals.

Alternative splicing: transcriptional regulatory network in agroforestry.

Alternative splicing (AS) in plants plays a key role in regulating the expression of numerous transcripts from a single gene in a regulatory pathway. Variable concentrations of growth regulatory hormones and external stimuli trigger alternative splicing to switch among different growth stages and adapt to environmental stresses. In the AS phenomenon, a spliceosome causes differential transcriptional modifications in messenger RNA (mRNAs), resulting in partial or complete retention of one or more introns as compared to fully spliced mRNA. Differentially expressed proteins translated from intron-retaining messenger RNA (mRNAir) perform vital functions in the feedback mechanism. At the post-transcriptional level, AS causes the remodeling of transcription factors (TFs) by the addition or deletion of binding domains to activate and/or repress transcription. In this study, we have summarized the specific role of AS in the regulation of gene expression through repression and activation of the transcriptional regulatory network under external stimuli and switch among developmental stages.

Abstract 6145: Alternative splicing of GSDMB modulates killer lymphocyte-triggered pyroptosis

Abstract Killer lymphocyte-mediated tumor cell killing is a vital and final step of anti-tumor protective immunity. Killer cells, including cytotoxic CD8 T cells and Natural Killer (NK) cells, deliver granzymes (Gzm) into target cells, which normally activates noninflammatory cell death, but becomes inflammatory when target cells express the gasdermin (GSDM) proteins responsible for pyroptosis. GzmA and GzmB cleave and activate GSDMB and GSDME, respectively. However, the role of GSDMB in anti-tumor immunity is unclear - GSDMB pore formation is controversial and GSDMB expression has been linked to both anti- and pro-tumor functions. Here we found that GSDMB splicing variants are functionally distinct. Cleaved N-terminal (NT) fragments of isoforms 3 and 4 caused pyroptosis, but isoforms 1, 2 and 5, which deleted or modified exon 6, did not. Structural analysis based on AlphaFold predictions and the cryoEM structures of GSDMA3 and GSDMD showed that pore formation required the formation of a functional stabilizing belt structural element near the C-terminus of the cleaved N-terminal fragment, which was disrupted in the non-cytotoxic alternatively spliced isoforms. NK attack of GSDMB3-expressing cells caused pyroptosis, but GSDMB4 cells died mostly by apoptosis, and GSDMB1/2 cells died only by apoptosis. GSDMB4 partially resisted NK cell-triggered cleavage, suggesting that only GSDMB3 is fully functional. GSDMB1-3 were the most abundant isoforms in tested cells and were similarly induced by IFNγ and a chemotherapy drug methotrexate. Expression of cytotoxic GSDMB3/4, but not GSDMB1/2, was associated with better outcome in bladder and cervical cancer, suggesting GSDMB-mediated pyroptosis was protective in those tumors. Our study uncovers a novel role of alternative splicing in modulating caner-associated pyroptosis, and suggests that tumors may manipulate GSDMB splicing to avoid pyroptosis. Thus, modulating GSDMB splicing to increase cytotoxic GSDMB variants but suppress non-cytotoxic GSDMB isoforms could improve anti-tumor immunity and have therapeutic utility. Citation Format: Qing Kong, Shiyu Xia, Xingxin Pan, Kaixiong Ye, Zhouyihan Li, Haoyan Li, Nidhi Sahni, S. Stephen Yi, Xing Liu, Hao Wu, Judy Lieberman, Zhibin Zhang. Alternative splicing of GSDMB modulates killer lymphocyte-triggered pyroptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6145.

Long non‐coding RNA‐regulated alternative splicing modulates key cancer pathway in lung adenocarcinoma

Long non‐coding RNA‐regulated alternative splicing modulates key cancer pathway in lung adenocarcinoma

Identification of a comprehensive alternative splicing function during epithelial-mesenchymal transition

Epithelial-to-mesenchymal transition (EMT) is the underlying mechanism for tumor metastasis and shows the metastatic potential of tumor cells. Although the transcriptional regulation of EMT has been well studied, the role of alternative splicing (AS) regulation in EMT remains largely uncharacterized. The rapid accumulation of RNA-seq datasets has provided the opportunities for developing computational methods to associate mRNA isoform variations with EMT. In this study, we propose regularization models to identify significant AS events during EMT. Our experimental results confirm that the predicted AS events are closely related to apoptosis, focal adhesion-invadopodium shift and tight junction formation that are essential during EMT. Therefore, our study highlights the broad role of posttranscriptional regulation during EMT and identifies key subsets of AS events serving as distinct regulatory nodes.