The notch pathway is activated in neoplastic progression in esophageal squamous cell carcinoma

Notch signaling pathway in cancer: from mechanistic insights to targeted therapies

Notch signaling, renowned for its role in regulating cell fate, organ development, and tissue homeostasis across metazoans, is highly conserved throughout evolution. The Notch receptor and its ligands are transmembrane proteins containing epidermal growth factor-like repeat sequences, typically necessitating receptor-ligand interaction to initiate classical Notch signaling transduction. Accumulating evidence indicates that the Notch signaling pathway serves as both an oncogenic factor and a tumor suppressor in various cancer types. Dysregulation of this pathway promotes epithelial-mesenchymal transition and angiogenesis in malignancies, closely linked to cancer proliferation, invasion, and metastasis. Furthermore, the Notch signaling pathway contributes to maintaining stem-like properties in cancer cells, thereby enhancing cancer invasiveness. The regulatory role of the Notch signaling pathway in cancer metabolic reprogramming and the tumor microenvironment suggests its pivotal involvement in balancing oncogenic and tumor suppressive effects. Moreover, the Notch signaling pathway is implicated in conferring chemoresistance to tumor cells. Therefore, a comprehensive understanding of these biological processes is crucial for developing innovative therapeutic strategies targeting Notch signaling. This review focuses on the research progress of the Notch signaling pathway in cancers, providing in-depth insights into the potential mechanisms of Notch signaling regulation in the occurrence and progression of cancer. Additionally, the review summarizes pharmaceutical clinical trials targeting Notch signaling for cancer therapy, aiming to offer new insights into therapeutic strategies for human malignancies.

Jag1/2 maintain esophageal homeostasis and suppress foregut tumorigenesis by restricting the basal progenitor cell pool

Basal progenitor cells are crucial for maintaining foregut (the esophagus and forestomach) homeostasis. When their function is dysregulated, it can promote inflammation and tumorigenesis. However, the mechanisms underlying these processes remain largely unclear. Here, we employ genetic mouse models to reveal that Jag1/2 regulate esophageal homeostasis and foregut tumorigenesis by modulating the function of basal progenitor cells. Deletion of Jag1/2 in mice disrupts esophageal and forestomach epithelial homeostasis. Mechanistically, Jag1/2 deficiency impairs activation of Notch signaling, leading to reduced squamous epithelial differentiation and expansion of basal progenitor cells. Moreover, Jag1/2 deficiency exacerbates the deoxycholic acid (DCA)-induced squamous epithelial injury and accelerates the initiation of squamous cell carcinoma (SCC) in the forestomach. Importantly, expression levels of JAG1/2 are lower in the early stages of human esophageal squamous cell carcinoma (ESCC) carcinogenesis. Collectively, our study demonstrates that Jag1/2 are important for maintaining esophageal and forestomach homeostasis and the onset of foregut SCC.

Commonalities and differences in the mutational signature and somatic driver mutation landscape across solid and hollow viscus organs

Advances in sequencing have revealed a highly variegated landscape of mutational signatures and somatic driver mutations in a range of normal tissues. Normal tissues accumulate mutations at varying rates ranging from 11 per cell per year in the liver, to 1879 per cell per year in the bladder. In addition, some normal tissues are also comprised of a large proportion of cells which possess driver mutations while appearing phenotypically normal, as in the oesophagus where a majority of cells harbour driver mutations. Individual tissue proliferation and mutation rate, unique mutagenic stimuli, and local tissue architecture contribute to this highly variegated landscape which confounds the functional characterization of driver mutations found in normal tissue. In particular, our understanding of the relationship between normal tissue somatic mutations and tumour initiation or future cancer risk remains poor. Here, we describe the mutational signatures and somatic driver mutations in solid and hollow viscus organs, highlighting unique characteristics in a tissue-specific manner, while simultaneously seeking to describe commonalities which can bring forward a basic unified theory on the role of these driver mutations in tumour initiation. We discuss novel findings which can be used to inform future research in this field.

Molecular Characterization of Esophageal Squamous Cell Carcinoma Using Quantitative Proteomics

Esophageal squamous cell carcinoma (ESCC) is a heterogeneous cancer associated with a poor prognosis in advanced stages. In India, it is the sixth most common cause of cancer-related mortality. In this study, we employed high-resolution mass spectrometry-based quantitative proteomics to characterize the differential protein expression pattern associated with ESCC. We identified several differentially expressed proteins including PDPN, TOP2A, POSTN and MMP2 that were overexpressed in ESCC. In addition, we identified downregulation of esophagus tissue-enriched proteins such as SLURP1, PADI1, CSTA, small proline-rich proteins such as SPRR3, SPRR2A, SPRR1A, KRT4, and KRT13, involved in squamous cell differentiation. We identified several overexpressed proteins mapped to the 3q24-29 chromosomal region, aligning with CNV alterations in this region reported in several published studies. Among these, we identified overexpression of SOX2, TP63, IGF2BP2 and RNF13 that are encoded by genes in the 3q26 region. Functional enrichment analysis revealed proteins involved in cell cycle pathways, DNA replication, spliceosome, and DNA repair pathways. We identified the overexpression of multiple proteins that play a major role in alleviating ER stress, including SYVN1 and SEL1L. The SYVN1/SEL1L complex is an essential part of the ER quality control machinery clearing misfolded proteins from the ER. SYVN1 is an E3 ubiquitin ligase that ubiquitinates ER-resident proteins. Interestingly, there are also other non-canonical substrates of SYVN1 which are known to play a crucial role in tumor progression. Thus, SYVN1 could be a potential therapeutic target in ESCC.

Notch1 mutations drive clonal expansion in normal esophageal epithelium but impair tumor growth

NOTCH1 mutant clones occupy the majority of normal human esophagus by middle age but are comparatively rare in esophageal cancers, suggesting NOTCH1 mutations drive clonal expansion but impede carcinogenesis. Here we test this hypothesis. Sequencing NOTCH1 mutant clones in aging human esophagus reveals frequent biallelic mutations that block NOTCH1 signaling. In mouse esophagus, heterozygous Notch1 mutation confers a competitive advantage over wild-type cells, an effect enhanced by loss of the second allele. Widespread Notch1 loss alters transcription but has minimal effects on the epithelial structure and cell dynamics. In a carcinogenesis model, Notch1 mutations were less prevalent in tumors than normal epithelium. Deletion of Notch1 reduced tumor growth, an effect recapitulated by anti-NOTCH1 antibody treatment. Notch1 null tumors showed reduced proliferation. We conclude that Notch1 mutations in normal epithelium are beneficial as wild-type Notch1 favors tumor expansion. NOTCH1 blockade may have therapeutic potential in preventing esophageal squamous cancer.

Potentially functional genetic variants of the Notch signaling pathway genes predict survival of Chinese patients with Esophageal Squamous Cell Carcinoma

BACKGROUND

The Notch signaling pathway is involved in progression of esophageal squamous cell carcinoma (ESCC), but the roles of single nucleotide polymorphisms (SNPs) of the Notch signaling pathway genes in the process remain unknown.

METHODS

The present study included 1,009 patients with histopathologically diagnosed ESCC at Fudan University Shanghai Cancer Center (FUSCC). The two-stage multivariate Cox proportional hazards regression analysis was used to estimate associations between 13,248 SNPs in 103 Notch signaling pathway genes and overall survival of the patients.

RESULTS

We found that overall survival of the patients was significantly associated with genotypes of HDAC9 rs1729318 (AT+TT vs AA: HR = 1.44, 95% CI = 1.16-1.80, P_combined = 0.001) and HDAC9 rs1339555498 (GT +TT vs GG: HR = 1.38, 95% CI = 1.10-1.74, P_combined = 0.005). Further receiver operator characteristic (ROC) curve analysis indicated that the model with both available clinical factors and these two SNPs improved the area under the ROC curve, compared with the model with clinical factors only (1-year: 0.66 vs. 0.64, P = 0.034). Additional expression quantitative trait loci (eQTL) analysis showed that the rs1729318 T variant genotypes were associated with increased mRNA expression levels of HDAC9 in normal esophageal muscular tissue (P = 0.003).

CONCLUSIONS

The results suggest that these two potential functional SNPs on HDAC9 may serve as biomarkers for predicting survival of ESCC patients. However, further studies are needed to confirm these findings.

Multiplex Tissue Imaging: Spatial Revelations in the Tumor Microenvironment

Simple Summary

Cancer is the leading cause of death worldwide, and the overall aging of the population results in an increased risk of a cancer diagnosis during a person’s lifetime. Diagnosis and treatment at an early stage will typically increase the chances of survival. Tumors can develop therapy resistance, and it is difficult to predict how individual patients will respond to therapy. Most studies that aim to resolve this problem have focused on studying the composition and characteristics of dissociated tumors, while ignoring the role of cell localization and interactions within the tumor microenvironment. In the past decade, technological innovations have enabled multiplex imaging analyses of intact tumors to study localization and interaction parameters, which can be used as biomarkers, or can be correlated with treatment responses and clinical outcomes.

Abstract

The tumor microenvironment is a complex ecosystem containing various cell types, such as immune cells, fibroblasts, and endothelial cells, which interact with the tumor cells. In recent decades, the cancer research field has gained insight into the cellular subtypes that are involved in tumor microenvironment heterogeneity. Moreover, it has become evident that cellular interactions in the tumor microenvironment can either promote or inhibit tumor development, progression, and drug resistance, depending on the context. Multiplex spatial analysis methods have recently been developed; these have offered insight into how cellular crosstalk dynamics and heterogeneity affect cancer prognoses and responses to treatment. Multiplex (imaging) technologies and computational analysis methods allow for the spatial visualization and quantification of cell–cell interactions and properties. These technological advances allow for the discovery of cellular interactions within the tumor microenvironment and provide detailed single-cell information on properties that define cellular behavior. Such analyses give insights into the prognosis and mechanisms of therapy resistance, which is still an urgent problem in the treatment of multiple types of cancer. Here, we provide an overview of multiplex imaging technologies and concepts of downstream analysis methods to investigate cell–cell interactions, how these studies have advanced cancer research, and their potential clinical implications.

Signaling pathways and their potential therapeutic utility in esophageal squamous cell carcinoma

Esophageal cancer is a complex gastrointestinal malignancy with an extremely poor outcome. Approximately 80% of cases of this malignancy in Asian countries including India are of squamous cell origin, termed Esophageal Squamous Cell Carcinoma (ESCC).The five-year survival rate in ESCC patients is less than 20%. Neo-adjuvant chemo-radiotherapy (NACRT) followed by surgical resection remains the major therapeutic strategy for patients with operable ESCC. However, resistance to NACRT and local recurrence after initial treatment are the leading cause of dismal outcomes in these patients. Therefore, an alternative strategy to promote response to the therapy and reduce the post-operative disease recurrence is highly needed. At the molecular level, wide variations have been observed in tumor characteristics among different populations, nevertheless, several common molecular features have been identified which orchestrate disease progression and clinical outcome in the malignancy. Therefore, determination of candidate molecular pathways for targeted therapy remains the mainstream idea of focus in ESCC research. In this review, we have discussed the key signaling pathways associated with ESCC, i.e., Notch, Wnt, and Nrf2 pathways, and their crosstalk during disease progression. We further discuss the recent developments of novel agents to target these pathways in the context of targeted cancer therapy. In-depth research of the signaling pathways, gene signatures, and a combinatorial approach may help in discovering targeted therapy for ESCC.

Metastatic HPV-Mediated Adenocarcinoma Arising from a Base of Tongue Primary: A Case Report with Cytomorphology and Molecular Findings with Review of the Literature

Human papillomavirus (HPV)-mediated squamous cell carcinomas of the oropharynx are common, however only rare cases of HPV-mediated oropharyngeal adenocarcinoma have been reported to date. In this report, we describe a 50 year old nonsmoking male who originally presented with an enlarging neck mass. Fine needle aspiration cytology confirmed an HPV-mediated adenocarcinoma. Subsequent surgery identified a 0.7 cm base of tongue primary HPV-mediated carcinoma with focal glandular differentiation and a 4.0 cm cystic lymph node metastasis demonstrating entirely glandular differentiation. Next generation sequencing of the metastasis detected a pathogenic NOTCH1 mutation.

Shooting at Moving and Hidden Targets-Tumour Cell Plasticity and the Notch Signalling Pathway in Head and Neck Squamous Cell Carcinomas

Head and Neck Squamous Cell Carcinoma (HNSCC) is often aggressive, with poor response to current therapies in approximately 40-50% of the patients. Current therapies are restricted to operation and irradiation, often combined with a small number of standard-of-care chemotherapeutic drugs, preferentially for advanced tumour patients. Only very recently, newer targeted therapies have entered the clinics, including Cetuximab, which targets the EGF receptor (EGFR), and several immune checkpoint inhibitors targeting the immune receptor PD-1 and its ligand PD-L1. HNSCC tumour tissues are characterized by a high degree of intra-tumour heterogeneity (ITH), and non-genetic alterations that may affect both non-transformed cells, such as cancer-associated fibroblasts (CAFs), and transformed carcinoma cells. This very high degree of heterogeneity likely contributes to acquired drug resistance, tumour dormancy, relapse, and distant or lymph node metastasis. ITH, in turn, is likely promoted by pronounced tumour cell plasticity, which manifests in highly dynamic and reversible phenomena such as of partial or hybrid forms of epithelial-to-mesenchymal transition (EMT), and enhanced tumour stemness. Stemness and tumour cell plasticity are strongly promoted by Notch signalling, which remains poorly understood especially in HNSCC. Here, we aim to elucidate how Notch signal may act both as a tumour suppressor and proto-oncogenic, probably during different stages of tumour cell initiation and progression. Notch signalling also interacts with numerous other signalling pathways, that may also have a decisive impact on tumour cell plasticity, acquired radio/chemoresistance, and metastatic progression of HNSCC. We outline the current stage of research related to Notch signalling, and how this pathway may be intricately interconnected with other, druggable targets and signalling mechanisms in HNSCC.

METTL3-mediated m6A mRNA modification promotes esophageal cancer initiation and progression via Notch signaling pathway

Esophageal cancer is a lethal malignancy with a high mortality rate, while the molecular mechanisms underlying esophageal cancer pathogenesis are still poorly understood. Here, we found that the N6-methyladenosine (m⁶A) methyltransferase-like 3 (METTL3) is significantly upregulated in esophageal squamous cell carcinoma (ESCC) and associated with poor patient prognosis. Depletion of METTL3 results in decreased ESCC growth and progression in vitro and in vivo. We further established ESCC initiation and progression models using Mettl3 conditional knockout mouse and revealed that METTL3-mediated m⁶A modification promotes ESCC initiation and progression in vivo. Moreover, using METTL3 overexpression ESCC cell model and Mettl3 conditional knockin mouse model, we demonstrated the critical function of METTL3 in promoting ESCC tumorigenesis in vitro and in vivo. Mechanistically, METTL3-catalyzed m⁶A modification promotes NOTCH1 expression and the activation of the Notch signaling pathway. Forced activation of Notch signaling pathway successfully rescues the growth, migration, and invasion capacities of METTL3-depleted ESCC cells. Our data uncovered important mechanistical insights underlying ESCC tumorigenesis and provided molecular basis for the development of novel strategies for ESCC diagnosis and treatment.

The Notch1 gene may control cell chemoresistance in esophageal squamous cell cancer

BACKGROUND

In our previous study, missense mutations in the Notch1 gene were found in chemotherapy-resistant esophageal squamous cell cancer (ESCC) patients. In this study, we explored changes in the interaction between Notch1 and DLL4 resulting from missense mutations.

METHODS

Bioinformatics analysis was performed to assess and compare the different biological structures and functions of wild type (WT) and mutation type (MT) sequences of Notch1. A genetic information search was performed, and the results were analyzed using in silico modeling. Homology modeling of the Notch1 protein was carried out using Swiss-Model software, and modeling of site-directed mutations was carried out using PyMOL software to observe the protein structure. The Notch1-DLL4 ligand-receptor complex protein model was constructed, Wincoot software was used to determine site-directed mutations, and a protein-ligand interaction profiler (PLIP) was used to calculate the noncovalent interactions in the complex.

RESULTS

The mutation site was located in the region where Notch1 binds to DLL4. A careful examination of the in silico structural model revealed that the mutation caused an alteration in the surface charge, and the water-bridge bonds of the interaction between Notch1-DLL4 increased in number from 5 to 7.

CONCLUSIONS

Notch1 gene missense mutation leads to an increase in the number of water-bridge bonds, thus enhancing the Notch1-DLL4 interaction, which may lead to tighter Notch1-DLL4 binding, either making the pathway easier to activate or increasing the length of time it is active.

Patient-derived xenograft: a developing tool for screening biomarkers and potential therapeutic targets for human esophageal cancers

Esophageal cancer (EC) represents a human malignancy, diagnosed often at the advanced stage of cancer and resulting in high morbidity and mortality. The development of precision medicine allows for the identification of more personalized therapeutic strategies to improve cancer treatment. By implanting primary cancer tissues into immunodeficient mice for expansion, patient-derived xenograft (PDX) models largely maintain similar histological and genetic representations naturally found in patients' tumor cells. PDX models of EC (EC-PDX) provide fine platforms to investigate the tumor microenvironment, tumor genomic heterogeneity, and tumor response to chemoradiotherapy, which are necessary for new drug discovery to combat EC in addition to optimization of current therapeutic strategies for EC. In this review, we summarize the methods used for establishing EC-PDX models and investigate the utilities of EC-PDX in screening predictive biomarkers and potential therapeutic targets. The challenge of this promising research tool is also discussed.

Quercetin pretreatment enhances the radiosensitivity of colon cancer cells by targeting Notch-1 pathway

Cancer stem-like cells are rare immortal cells within tumor, which are thought to play important roles in ionizing radiation (IR) therapy-resistance. Quercetin is a natural flavonoid with potential anti-cancer properties without significant cytotoxicity in normal tissues. In this study, we demonstrated that quercetin-IR combination treatment exhibited more dramatic anti-cancer effect than either quercetin or IR treatment alone via targeting colon cancer stem cells (CSCs) and inhibiting the Notch-1 signaling. These effects were further verified by in vivo studies which showed remarkable decrease of the CSCs markers and the expression of Notch-1 signaling proteins in human colon cancer xenografts in nude mice. Co-treatment with quercetin and low dose of radiation significantly reduced the expressions of all five proteins of γ-secretase complex in HT-29 and DLD-1 cells. In addition, ectopic expression of the Notch intracellular domain (NICD) partly reversed the inhibition effects by the combination therapy. In conclusion, our results indicated that the combination of quercetin (20 μM) and IR (5Gy) might be a promising therapeutic strategy for colon cancer treatment by targeting colon cancer stem-like cells and inhibiting the Notch-1 signaling. In future studies, we intend to further explore the potential therapeutic efficacy of the quercetin-radiation combination treatment in clinical trials.

FLI-06 Intercepts Notch Signaling And Suppresses The Proliferation And Self-renewal Of Tongue Cancer Cells

Purpose

The Notch signaling pathway plays an oncogenic role in tongue squamous cell carcinoma. The aim of this study was to inhibit the proliferation and self-renewal of tongue cancer cells by applying Notch signaling pathway inhibitor FLI-06 (Selleck, USA) and to lay a foundation for the clinically targeted treatment of tongue cancer for the future.

Methods

The mRNA expression level of Notch1 and the overall survival rate of patients with tongue cancer were examined by analyzing the TCGA database. Tongue cancer cells were treated with FLI-06. Cell proliferation, apoptosis, and stem cell self-renewal ability were tested in appropriate ways. A xenograft mouse model was established to observe tumor growth.

Results

From the TCGA data, we demonstrated that patients with high expression of Notch1 had a poor prognosis. We observed that the Notch signaling pathway inhibitor FLI-06 can restrain the activation of the Notch signaling pathway, decrease cell proliferation and induce cell apoptosis in vitro. The xenograft experiment indicated that intraperitoneal injection of FLI-06 inhibited tumor growth and increased cell apoptosis. FLI-06 suppressed both the mRNA and protein expression of Notch receptor and Notch targeted genes. We also observed that FLI-06 suppressed the proliferation of tongue cancer stem cells.

Conclusion

FLI-06 can block the proliferation and self-renewal of tongue cancer cells. It is inferred that this compound, which inhibits the Notch signaling pathway, may serve as a potential targeted drug for the treatment of tongue cancer in the clinic.

Genomic characterization of early-stage esophageal squamous cell carcinoma in a Japanese population

Major risk factors for esophageal squamous cell carcinoma (ESCC) are smoking, alcohol consumption, and single nucleotide polymorphisms in ADH1B and ALDH2. Several groups have reported large-scale genomic analyses of ESCCs. However, the specific genetic changes that promote the development of ESCC have not been characterized. We performed exome sequencing of 16 fresh esophageal squamous cell neoplasms and targeted sequencing of 128 genes in 52 archival specimens, of which 26 were cancerous, and 26 were adjacent normal tissue, from Japanese ESCC patients. We found significantly more somatic mutations in TP53 and NOTCH1, CDKN2A deletions, and CCND1 amplifications in cancerous areas than in non-cancerous areas, consistent with previous studies that have characterized them as tumor suppressors and oncogenes. These data suggest that mutations, deletions, and amplifications, which alter the function of TP53, NOTCH1, CDKN2A, and CCND1, are the key changes that promote the transformation of esophageal mucosa to ESCC.

Notch Signaling Affects Oral Neoplasm Cell Differentiation and Acquisition of Tumor-Specific Characteristics

Histopathological findings of oral neoplasm cell differentiation and metaplasia suggest that tumor cells induce their own dedifferentiation and re-differentiation and may lead to the formation of tumor-specific histological features. Notch signaling is involved in the maintenance of tissue stem cell nature and regulation of differentiation and is responsible for the cytological regulation of cell fate, morphogenesis, and/or development. In our previous study, immunohistochemistry was used to examine Notch expression using cases of odontogenic tumors and pleomorphic adenoma as oral neoplasms. According to our results, Notch signaling was specifically associated with tumor cell differentiation and metaplastic cells of developmental tissues. Notch signaling was involved in the differentiation of the ductal epithelial cells of salivary gland tumors and ameloblast-like cells of odontogenic tumors. However, Notch signaling was also involved in squamous metaplasia, irrespective of the type of developmental tissue. In odontogenic tumors, Notch signaling was involved in epithelial–mesenchymal interactions and may be related to tumor development and tumorigenesis. This signaling may also be associated with the malignant transformation of ameloblastomas. Overall, Notch signaling appears to play a major role in the formation of the characteristic cellular composition and histological features of oral neoplasms, and this involvement has been reviewed here.

Loss of nuclear NOTCH1, but not its negative regulator NUMB, is an independent predictor of cervical malignancy

The participation of NOTCH signaling in invasive cervical cancer (ICC) remains controversial since both tumor suppressive and oncogenic properties have been described. Additionally, the role of NUMB, a negative regulator of NOTCH, remains unclear in ICC. We aimed to investigate the role of NOTCH1 and NUMB expression and their localization in cervical intraepithelial neoplasia (CIN) and ICC samples. A total of 144 biopsies were obtained from the Instituto Nacional de Cancerología, México from 2004 to 2017, and were subjected to immunohistochemistry for NOTCH1 and NUMB. We found that nuclear NOTCH1 expression was more frequently found in CIN samples compared with ICC (77.55% vs. 15.79%, p = 0.001). NUMB was almost exclusively found in the nucleus of CIN samples (32.65% vs. 6.32%, p = 0.001). Cytoplasmic expression of NOTCH1 (44.21%) and NUMB (35.79%) was the most frequent localization in ICC. Multivariable-adjusted analysis showed that the loss of nuclear NOTCH1 expression was an independent predictor of malignancy (β = -3.428, 95% confidence interval [95% CI] = -5.127, -1.728, p = 0.001). In contrast, the association between cytoplasmic NUMB expression and cervical cancer was lost after adjusting for nuclear NOTCH1 expression (β = 2.074, 95% [CI] = -0.358, 4.506, P = 0.094). Additionally, patients with cytoplasmic NOTCH1 expression showed a borderline association with longer overall survival (OS) than those with nuclear NOTCH1 expression (P = 0.08). Our data suggest that the loss of nuclear NOTCH1 but not NUMB might be an independent predictor of malignancy in cervical cancer.

The nuclear transportation routes of membrane-bound transcription factors

Membrane-bound transcription factors (MTFs) are transcription factors (TFs) that are anchored in membranes in a dormant state. Activated by external or internal stimuli, MTFs are released from parent membranes and are transported to the nucleus. Existing research indicates that some plasma membrane (PM)-bound proteins and some endoplasmic reticulum (ER) membrane-bound proteins have the ability to enter the nucleus. Upon specific signal recognition cues, some PM-bound TFs undergo proteolytic cleavage to liberate the intracellular fragments that enter the nucleus to control gene transcription. However, lipid-anchored PM-bound proteins enter the nucleus in their full length for depalmitoylation. In addition, some PM-bound TFs exist as full-length proteins in cell nucleus via trafficking to the Golgi and the ER, where membrane-releasing mechanisms rely on endocytosis. In contrast, the ER membrane-bound TFs relocate to the nucleus directly or by trafficking to the Golgi. In both of these pathways, only the fragments of the ER membrane-bound TFs transit to the nucleus. Several different nuclear trafficking modes of MTFs are summarized in this review, providing an effective supplement to the mechanisms of signal transduction and gene regulation. Moreover, targeting intracellular movement pathways of disease-associated MTFs may significantly improve the survival of patients.