Epigenetic regulation of ZEB1-RAB25/ESRP1 axis plays a critical role in phenylbutyrate treatment-resistant breast cancer

Research progress of ankyrin repeat domain 1 protein: an updated review

Ankyrin repeat domain 1 (Ankrd1) is an acute response protein that belongs to the muscle ankyrin repeat protein (MARP) family. Accumulating evidence has revealed that Ankrd1 plays a crucial role in a wide range of biological processes and diseases. This review consolidates current knowledge on Ankrd1's functions in myocardium and skeletal muscle development, neurogenesis, cancer, bone formation, angiogenesis, wound healing, fibrosis, apoptosis, inflammation, and infection. The comprehensive profile of Ankrd1 in cardiovascular diseases, myopathy, and its potential as a candidate prognostic and diagnostic biomarker are also discussed. In the future, more studies of Ankrd1 are warranted to clarify its role in diseases and assess its potential as a therapeutic target.

ANKRD1 Promotes Breast Cancer Metastasis by Activating NF-κB-MAGE-A6 Pathway

Early detection and surgical excision of tumors have helped improve the survival rate of patients with breast cancer. However, patients with metastatic cancer typically have a poor prognosis. In this study, we propose that ANKRD1 promotes metastasis of breast cancer. ANKRD1 was found to be highly expressed in the MDA-MB-231 and MDA-LM-2 highly metastatic breast cancer cell lines compared to the non-metastatic breast cancer cell lines (MCF-7, ZR-75-30, T47D) and normal breast cancer cells (MCF-10A). Furthermore, high-grade tumors showed increased levels of ANKRD1 compared to low-grade tumors. Both in vitro and in vivo functional studies demonstrated the essential role of ANKRD1 in cancer cell migration and invasion. The previous studies have suggested a significant role of NF-κB and MAGE-A6 in breast cancer metastasis, but the upstream regulators of this axis are not well characterized. Our study suggests that ANKRD1 promotes metastasis of breast cancer by activating NF-κB as well as MAGE-A6 signaling. Our findings show that ANKRD1 is a potential therapeutic target and a diagnostic marker for breast cancer metastasis.

Molecular characterization of ANKRD1 in rhabdomyosarcoma cell lines: expression, localization, and proteasomal degradation

Rhabdomyosarcoma (RMS) is the most common soft tissue malignancy in children and adolescents. Respecting the age of the patients and the tumor aggressiveness, investigation of the molecular mechanisms of RMS tumorigenesis is directed toward the identification of novel therapeutic targets. To contribute to a better understanding of the molecular pathology of RMS, we investigated ankyrin repeat domain 1 (ANKRD1), designated as a potential marker for differential diagnostics. In this study, we used three RMS cell lines (SJRH30, RD, and HS-729) to assess its expression profile, intracellular localization, and turnover. They express wild-type ANKRD1, as judged by the sequencing of the open reading frame. Each cell line expressed a different amount of ANKRD1 protein, although the transcript level was similar. According to western blot analysis, ANKRD1 protein was expressed at detectable levels in the SJRH30 and RD cells (SJRH30 > RD), but not in the HS-729, even after immunoprecipitation. Immunocytochemistry revealed nuclear and cytoplasmic localization of ANKRD1 in all examined cell lines. Moreover, the punctate pattern of ANKRD1 staining in the nuclei of RD and HS-729 cells overlapped with coilin, indicating its association with Cajal bodies. We have shown that RMS cells are not able to overexpress ANKRD1 protein, which can be attributed to its proteasomal degradation. The unsuccessful attempt to overexpress ANKRD1 in RMS cells indicates the possibility that its overexpression may have detrimental effects for RMS cells and opens a window for further research into its role in RMS pathogenesis and for potential therapeutic targeting.

Interferon-Gamma-Inducible Protein 16 Inhibits Hepatocellular Carcinoma via Interferon Regulatory Factor 3 on Chemosensitivity

BACKGROUND AND AIM

Previous reports have suggested IFI16 as a tumor suppressor in hepatocellular carcinoma (HC). Nonetheless, the biological significance of IFI16 and its mechanism concerning resistance to cisplatin (DDP) in HC requires further exploration.

METHODS

Samples of tumor and corresponding para-carcinoma tissues were acquired from patients with HC. Furthermore, DDP-resistant cell lines of HC, specifically HCC, Huh7 and Hepatoblastoma, HepG3, were generated by gradually increasing the concentration of DDP. Cell apoptosis and DNA damage were evaluated by utilizing flow cytometry assay and TUNEL staining. The interaction between IFI16 and interferon regulatory factor 3 (IRF3) proteins were analyzed using Co-Immunoprecipitation (Co-IP) assay. In vivo assays were conducted by establishing HC subcutaneous xenograft tumor models.

RESULTS

The study found a reduction in IFI16 expression in both HC tissues and DDP-resistant HC cell lines. The binding of IFI16 to IRF3 regulated DNA damage-associated markers in vitro. Overexpression of IFI16 heightened the susceptibility of DDP-induced apoptosis and DNA damage, which was counteracted by IRF3 knockdown, while strengthened by IRF3 overexpression. Moreover, overexpression of IFI16 diminished in vivo DDP-resistant HC tumorigenicity.

CONCLUSION

In summary, our findings suggest that IFI16 serves as a tumor suppressor in HC by promoting DNA damage via its interaction with IRF3, thereby reversing DDP resistance.

CEMIP (HYBID, KIAA1199): structure, function and expression in health and disease

CEMIP (cell migration-inducing protein), also known as KIAA1199 or HYBID, is a protein involved in the depolymerisation of hyaluronic acid (HA), a major glycosaminoglycan component of the extracellular matrix. CEMIP was originally described in patients affected by nonsyndromic hearing loss and has subsequently been shown to play a key role in tumour initiation and progression, as well as arthritis, atherosclerosis and idiopathic pulmonary fibrosis. Despite the vast literature associating CEMIP with these diseases, its biology remains elusive. The present review article summarises all the major scientific evidence regarding its structure, function, role and expression, and attempts to cast light on a protein that modulates EMT, fibrosis and tissue inflammation, an unmet key aspect in several inflammatory disease conditions.

Epigenetic drugs as new emerging therapeutics: What is the scale's orientation of application and challenges?

Epigenetics is the study of heritable changes in gene expression or function without altering the DNA sequence. Important factors are part of epigenetic events, such as methylation, DNA histone rearrangements, nucleosome transposition, and non-coding RNAs. Dysregulated epigenetic mechanics are associated with various cancers' initiation, development, and metastasis. It is known that the occurrence and development of cancer can be controlled by regulating unexpected epigenetic events. Epi-drugs are used singly or in combination with chemotherapy and enhance antitumor activity, reduce drug resistance, and stimulate the host immune response. Despite these benefits, epigenetic therapy as a single therapy or in combination with other drugs leads to adverse effects. This review article introduces and compares the advantages, disadvantages, and side effects of using these drugs for the first time since their introduction. Also, this article describes the mechanism of action of various epigenetic drugs. Recommendations for future use of epigenetic drugs as cancer therapeutics are suggested as an overall conclusion.

Underlying mechanisms of epithelial splicing regulatory proteins in cancer progression

Cancer is the second-leading disease-related cause of global mortality after cardiovascular disease. Despite significant advances in cancer therapeutic strategies, cancer remains one of the major obstacles to human life extension. Cancer pathogenesis is extremely complicated and not fully understood. Epithelial splicing regulatory proteins (ESRPs), including ESRP1 and ESRP2, belong to the heterogeneous nuclear ribonucleoprotein family of RNA-binding proteins and are crucial regulators of the alternative splicing of messenger RNAs (mRNAs). The expression and activity of ESRPs are modulated by various mechanisms, including post-translational modifications and non-coding RNAs. Although a growing body of evidence suggests that ESRP dysregulation is closely associated with cancer progression, the detailed mechanisms remain inconclusive. In this review, we summarize recent findings on the structures, functions, and regulatory mechanisms of ESRPs and focus on their underlying mechanisms in cancer progression. We also highlight the clinical implications of ESRPs as prognostic biomarkers and therapeutic targets in cancer treatment. The information reviewed herein could be extremely beneficial to the development of individualized therapeutic strategies for cancer patients.

Regulation of ZEB1 Function and Molecular Associations in Tumor Progression and Metastasis

Zinc finger E-box binding homeobox 1 (ZEB1) is a pleiotropic transcription factor frequently expressed in carcinomas. ZEB1 orchestrates the transcription of genes in the control of several key developmental processes and tumor metastasis via the epithelial-to-mesenchymal transition (EMT). The biological function of ZEB1 is regulated through pathways that influence its transcription and post-transcriptional mechanisms. Diverse signaling pathways converge to induce ZEB1 activity; however, only a few studies have focused on the molecular associations or functional changes of ZEB1 by post-translational modifications (PTMs). Due to the robust effect of ZEB1 as a transcription repressor of epithelial genes during EMT, the contribution of PTMs in the regulation of ZEB1-targeted gene expression is an active area of investigation. Herein, we review the pivotal roles that phosphorylation, acetylation, ubiquitination, sumoylation, and other modifications have in regulating the molecular associations and behavior of ZEB1. We also outline several questions regarding the PTM-mediated regulation of ZEB1 that remain unanswered. The areas of research covered in this review are contributing to new treatment strategies for cancer by improving our mechanistic understanding of ZEB1-mediated EMT.

Caveolae-Associated Molecules, Tumor Stroma, and Cancer Drug Resistance: Current Findings and Future Perspectives

Simple Summary

Cell membranes contain small invaginations called caveolae. They are a specialized lipid domain and orchestrate cellular signaling events, mechanoprotection, and lipid homeostasis. Formation of the caveolae depends on two classes of proteins, the caveolins and cavins, which form large complexes that allow their self-assembly into caveolae. Loss of either of these two proteins leads to distortion of the caveolae structure and disruption of many physiological processes that affect diseases of the muscle, metabolic states governing lipids, and the glucose balance as well as cancers. In cancers, the expression of caveolins and cavins is heterogenous, and they undergo alterations both in the tumors and the surrounding tumor microenvironment stromal cells. Remarkably, their expression and function has been associated with resistance to many cancer drugs. Here, we summarize the current knowledge of the resistance mechanisms and how this knowledge could be applied into the clinic in future.

Abstract

The discovery of small, “cave-like” invaginations at the plasma membrane, called caveola, has opened up a new and exciting research area in health and diseases revolving around this cellular ultrastructure. Caveolae are rich in cholesterol and orchestrate cellular signaling events. Within caveola, the caveola-associated proteins, caveolins and cavins, are critical components for the formation of these lipid rafts, their dynamics, and cellular pathophysiology. Their alterations underlie human diseases such as lipodystrophy, muscular dystrophy, cardiovascular disease, and diabetes. The expression of caveolins and cavins is modulated in tumors and in tumor stroma, and their alterations are connected with cancer progression and treatment resistance. To date, although substantial breakthroughs in cancer drug development have been made, drug resistance remains a problem leading to treatment failures and challenging translation and bench-to-bedside research. Here, we summarize the current progress in understanding cancer drug resistance in the context of caveola-associated molecules and tumor stroma and discuss how we can potentially design therapeutic avenues to target these molecules in order to overcome treatment resistance.

Transcriptomics and Metabolomics Integration Reveals Redox-Dependent Metabolic Rewiring in Breast Cancer Cells

Rewiring glucose metabolism toward aerobic glycolysis provides cancer cells with a rapid generation of pyruvate, ATP, and NADH, while pyruvate oxidation to lactate guarantees refueling of oxidized NAD⁺ to sustain glycolysis. CtPB2, an NADH-dependent transcriptional co-regulator, has been proposed to work as an NADH sensor, linking metabolism to epigenetic transcriptional reprogramming. By integrating metabolomics and transcriptomics in a triple-negative human breast cancer cell line, we show that genetic and pharmacological down-regulation of CtBP2 strongly reduces cell proliferation by modulating the redox balance, nucleotide synthesis, ROS generation, and scavenging. Our data highlight the critical role of NADH in controlling the oncogene-dependent crosstalk between metabolism and the epigenetically mediated transcriptional program that sustains energetic and anabolic demands in cancer cells.

ESRP1 regulates alternative splicing of CARM1 to sensitize small cell lung cancer cells to chemotherapy by inhibiting TGF-β/Smad signaling

Epithelial splicing regulatory protein 1 (ESRP1) is an RNA-binding protein that regulates alternative splicing of mRNA. ESRP1 plays an important role in chemoresistance of various cancers, including breast cancer, colon cancer and non-small cell lung cancer. However, the role of ESRP1 and its mechanism in small cell lung cancer (SCLC) chemoresistance remains unclear. In this study, we found that ESRP1 is significantly downregulated in SCLC chemo-resistant cells compared with chemo-sensitive cells. Moreover, the expression of ESRP1 was significantly lower in SCLC tissues than that in normal adjacent tissues and positively correlated with overall survival. Overexpression of ESRP1 increased SCLC chemosensitivity, and induced cell apoptosis and cell cycle arrest, whereas knockdown of ESRP1 induced the opposite effects. ESRP1 could inhibit the growth of SCLC in vivo. Through mRNA transcriptome sequencing, we found that ESRP1 regulates coactivator-associated arginine methyltransferase 1 (CARM1) to produce two different transcripts CARM1FL and CARM1ΔE15 by alternative splicing. ESRP1 affects the chemoresistance of SCLC by changing the content of different transcripts of CARM1. Furthermore, CARM1 regulates arginine methylation of Smad7, activates the TGF-β/Smad pathway and induces epithelial-to-mesenchymal transition (EMT), thereby promoting SCLC chemoresistance. Collectively, our study firstly demonstrates that ESRP1 inhibits the TGF-β/Smad signaling pathway by regulating alternative splicing of CARM1, thereby reversing chemoresistance of SCLC. The splicing factor ESRP1 may serve as a new drug resistance marker molecule and a potential therapeutic target in SCLC patients.

Ectopic Expression of Ankrd2 Affects Proliferation, Motility and Clonogenic Potential of Human Osteosarcoma Cells

Ankrd2 is a protein known for being mainly expressed in muscle fibers, where it participates in the mechanical stress response. Since both myocytes and osteoblasts are mesenchymal-derived cells, we were interested in examining the role of Ankrd2 in the progression of osteosarcoma which features a mechano-stress component. Although having been identified in many tumor-derived cell lines and -tissues, no study has yet described nor hypothesized any involvement for this protein in osteosarcoma tumorigenesis. In this paper, we report that Ankrd2 is expressed in cell lines obtained from human osteosarcoma and demonstrate a contribution by this protein in the pathogenesis of this insidious disease. Ankrd2 involvement in osteosarcoma development was evaluated in clones of Saos2, U2OS, HOS and MG63 cells stably expressing Ankrd2, through the investigation of hallmark processes of cancer cells. Interestingly, we found that exogenous expression of Ankrd2 influenced cellular growth, migration and clonogenicity in a cell line-dependent manner, whereas it was able to improve the formation of 3D spheroids in three out of four cellular models and enhanced matrix metalloproteinase (MMP) activity in all tested cell lines. Conversely, downregulation of Ankrd2 expression remarkably reduced proliferation and clonogenic potential of parental cells. As a whole, our data present Ankrd2 as a novel player in osteosarcoma development, opening up new therapeutic perspectives.

Age-related DNA methylation in paired normal and tumour breast tissue in Chinese breast cancer patients

Age-related DNA methylation is a potential mechanism contributing to breast cancer development. Studies of primarily Caucasian women have identified many CpG sites of age-related methylation in non-diseased breast tissue possibly driving cancer development over time. There is a paucity of studies involving Asian women whose ages at breast cancer onset are usually younger than Caucasians. We identified the 181 most consistent age-related methylation events in non-diseased breast tissue across published studies. Age-related methylation events were measured in adjacent normal and breast tumour tissue in an exclusively Asian population at the previously identified age-related methylation sites. Age-related methylation was found in 118 probes in adjacent normal breast tissue. Methylation of 99% of these sites was increased with age and predominantly located on CpG islands in promoter regions. To ascertain biological relevance to breast cancer, we focused on the 37 sites with overall higher methylation in tumour compared to adjacent normal samples. Some sites positively related to age, including AQP5 and CORO6, inversely correlated with gene expression. Several others have known involvement in suppression of carcinogenesis including GPC5 and SST, suggesting that perturbation of epigenetic regulation at these sites due to ageing may contribute to the progression of carcinogenesis. This study highlights an age-related methylation landscape in non-tumour tissue, consistent not just across studies, but also across different populations. We present candidate age-related methylation sites warranting further investigation as potential epigenetic drivers of breast cancer. They may serve as potential targets of site-specific demethylation intervention strategies for the prevention of age-related breast cancer.

A novel metastatic promoter CEMIP and its downstream molecular targets and signaling pathway of cellular migration and invasion in SCLC cells based on proteome analysis

PURPOSE

Metastasis is an unavoidable event happened among almost all small cell lung cancer (SCLC) patients. However, the molecular driven factors have not been elucidated. Recently, a novel hydrolase called cell migration inducing hyaluronidase (CEMIP) triggered both migration and invasion in many tumors but not SCLC. Therefore, in this study, we verified that CEMIP promoted migration and invasion in SCLC and applied proteomics analysis to screen out potential target profiles and the signaling pathway related to CEMIP regulation.

METHOD

Immunofluorescence was conducted to exam the expression of CEMIP on SCLC and paired adjacent normal tissues among enrollment. RT-qPCR and Western blot (WB) assays were conducted to valuate cellular protein and mRNA expression of CEMIP and EMT markers. Lentivirus-CEMIP-shRNAs and CEMIP plasmid were used for expression manipulating. Changes of cellular migration and invasion were tested through transwell assays. Tandem Mass Tag (TMT) peptide labeling coupled with LC-MS/MS was used for quantifying proteins affected by reducing expression of CEMIP on H446 cells.

RESULTS

The expression of CEMIP showed 1.64 ± 0.16-fold higher in SCLC tissues than their normal counterpart. Decreasing the expression of CEMIP on SCLC cells H446 regressed both cellular migration and invasion ability, whereas the promoting cellular migration and invasion was investigated through over-expressing CEMIP on H1688. Proteomic and bioinformatics analysis revealed that total 215 differentially expressed proteins (DEPs) that either their increasing or decreasing relative expression met threshold of 1.2-fold changes with p value ≤ 0.05. The dramatic up-regulated DEPs included an unidentified peptide sequence (encoded by cDNA FLJ52096) SPICE1 and CRYAB, while the expression of S100A6 was largely down-regulated. DEPs mainly enriched on caveolae of cellular component, calcium ion binding of biological process and epithelial cell migration of molecular function. KEGG enrichment indicated that DEPs mainly exerted their function on TGF-β, GABAergic synapse and MAPK signaling pathway.

CONCLUSION

It is the first report illustrating that CEMIP might be one of the metastatic triggers in SCLC. And also, it provided possible molecular mechanism cue and potential downstream target on CEMIP-induced cellular migration and invasion on SCLC.

Comprehensive Exploration to Identify Predictive DNA Markers of ΔNp63/SOX2 in Drug Resistance in Human Esophageal Squamous Cell Carcinoma

BACKGROUND

OBP-801 is a novel histone deacetylase inhibitor being developed as an anticancer drug. In this study, we explored genes to predict drug resistance in human cancer.

METHODS

OBP-801 resistance was assessed in 37 strains of human cancer cell lines. Expression microarrays harboring 54,675 genes were used to focus on candidate genes, which were validated for both functional and clinical relevance in esophageal squamous cell carcinoma (ESCC).

RESULTS

OBP-801 is sensitive to esophageal, gastric, and thyroid cancer, and resistant to some esophageal and colorectal cancers. We therefore used ESCC to explore genes. Comprehensive exploration focused on ΔNp63/SOX2, which were both genetically and epigenetically overexpressed in ESCC. Genomic amplifications of ΔNp63/SOX2 were tightly correlated each other (r = 0.81). Importantly, genomic amplification of ΔNp63/SOX2 in the resected tumors after neoadjuvant chemotherapy was significantly associated with histological grade of response (G1). Forced expression of either of these two genes did not induce each other, suggesting that their functional relevances were independent and showed robust drug resistance in OBP-801, as well as 5-fluorouracil. Furthermore, ΔNp63 could exert a potent oncogenic potential. RNA interference of ΔNp63 supported its oncological properties, as well as drug resistance.

CONCLUSION

Comprehensive exploration of genes involved in anticancer drug residence could identify critical oncogenes of ΔNp63/SOX2 that would predict chemotherapy response in ESCC.

Comprehensive Genetic Search to Clarify the Molecular Mechanism of Drug Resistance Identifies ASCL2-LEF1/TSPAN8 Axis in Colorectal Cancer

BACKGROUND

Treatment-resistance genes limiting anticancer therapy have not been well clarified in colorectal cancer (CRC). We explored gene expression profiles to identify biomarkers for predicting treatment resistance to an anticancer drug in CRC.

METHODS

Six CRC cell lines were treated with phenylbutyrate (PB). The gene expression profiles were then compared using microarrays (harboring 54,675 genes), and genes associated with PB resistance were identified. Candidate genes were functionally examined in cell lines and clinically validated for treatment resistance in clinical samples.

RESULTS

Both DLD1 and HCT15 cells were PB resistant, while HCT116 cells were identified as PB sensitive. On microarray analysis, among the PB resistance-related genes, the expression of the genes ASCL2, LEF1, and TSPAN8 was clearly associated with PB resistance. PB-sensitive cells transfected with one of these three genes exhibited significant (P < 0.001) augmentation of PB resistance; ASCL2 induced expression of both LEF1 and TSPAN8, while neither LEF1 nor TSPAN8 induced ASCL2. RNA interference via ASCL2 knockdown made PB-resistant cells sensitive to PB and inhibited both genes. ASCL2 knockdown also played a critical role in sensitivity to treatment by 5-fluorouracil and radiotherapy in addition to PB. Finally, ASCL2 expression was significantly correlated with histological grade of rectal cancer with preoperative chemoradiation therapy.

CONCLUSIONS

ASCL2 was identified as a causative gene involved in therapeutic resistance against anticancer treatments in CRC.

ZEB2 stably represses RAB25 expression through epigenetic regulation by SIRT1 and DNMTs during epithelial-to-mesenchymal transition

Background

Epithelial mesenchymal transition (EMT) is tightly regulated by a network of transcription factors (EMT-TFs). Among them is the nuclear factor ZEB2, a member of the zinc-finger E-box binding homeobox family. ZEB2 nuclear localization has been identified in several cancer types, and its overexpression is correlated with the malignant progression. ZEB2 transcriptionally represses epithelial genes, such as E-cadherin (CDH1), by directly binding to the promoter of the genes it regulates and activating mesenchymal genes by a mechanism in which there is no full agreement. Recent studies showed that EMT-TFs interact with epigenetic regulatory enzymes that alter the epigenome, thereby providing another level of control. The role of epigenetic regulation on ZEB2 function is not well understood. In this study, we aimed to characterize the epigenetic effect of ZEB2 repressive function on the regulation of a small Rab GTPase RAB25.

Results

Using cellular models with conditional ZEB2 expression, we show a clear transcriptional repression of RAB25 and CDH1. RAB25 contributes to the partial suppression of ZEB2-mediated cell migration. Furthermore, a highly significant reverse correlation between RAB25 and ZEB2 expression in several human cancer types could be identified. Mechanistically, ZEB2 binds specifically to E-box sequences on the RAB25 promoter. ZEB2 binding is associated with the local increase in DNA methylation requiring DNA methyltransferases as well as histone deacetylation (H3K9Ac) depending on the activity of SIRT1. Surprisingly, SIRT1 and DNMTs did not interact directly with ZEB2, and while SIRT1 inhibition decreased the stability of long-term repression, it did not prevent down-regulation of RAB25 and CDH1 by ZEB2.

Conclusions

ZEB2 expression is resulting in drastic changes at the chromatin level with both clear DNA hypermethylation and histone modifications. Here, we revealed that SIRT1-mediated H3K9 deacetylation helps to maintain gene repression but is not required for the direct ZEB2 repressive function. Targeting epigenetic enzymes to prevent EMT is an appealing approach to limit cancer dissemination, but inhibiting SIRT1 activity alone might have limited effect and will require drug combination to efficiently prevent EMT.

Electronic supplementary material

The online version of this article (10.1186/s13072-018-0239-4) contains supplementary material, which is available to authorized users.

Carcinosarcoma of the esophagus: A report of 6 cases associated with zinc finger E-box-binding homeobox 1 expression

Esophageal carcinosarcoma (ECS) has been suggested to result from an epithelial mesenchymal transition (EMT) phenomenon. However, knowledge on its underlying molecular features is limited. The clinical and pathological features, and the prognosis of ECS require further investigation. In the present study, a total of 325 patients with esophageal tumors were observed between January 2004 and December 2014, of which 6 patients were diagnosed pathologically with ECS. The clinicopathological features were compared with those of corresponding cases with the identical pathological T stage (pT) of esophageal squamous cell carcinoma (ESCC). In terms of the clinical T stage (cT), the 6 cases were composed of cT1, cT2, cT3 and cT4 in 1, 1, 3 and 1 case, respectively. Nevertheless, pT was eventually diagnosed as pT1 in all cases. There was a large discrepancy between clinically diagnosed depth of tumor invasion prior to surgery and depth of tumor invasion following surgery. Zinc finger E-box-binding homeobox 1 (ZEB1), an EMT-associated transcription factor, was expressed only in the sarcoma component in all 6 cases of ECS. The ECS cases had a significantly poorer prognosis compared with the 115 pT1 ESCC cases. The present study suggests that the depth of invasion of ECS lesions does not correspond with their respective size, and the EMT of the carcinoma component may affect the prognosis by overexpression of the ZEB1 gene.

Ankyrin Repeat Domain 1 Overexpression is Associated with Common Resistance to Afatinib and Osimertinib in EGFR-mutant Lung Cancer

Overcoming acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is critical in combating EGFR-mutant non-small cell lung cancer (NSCLC). We tried to construct a novel therapeutic strategy to conquer the resistance to second-and third-generation EGFR-TKIs in EGFR-positive NSCLC patients. We established afatinib- and osimertinib-resistant lung adenocarcinoma cell lines. Exome sequencing, cDNA array and miRNA microarray were performed using the established cell lines to discover novel therapeutic targets associated with the resistance to second-and third-generation EGFR-TKIs. We found that ANKRD1 which is associated with the epithelial-mesenchymal transition (EMT) phenomenon and anti-apoptosis, was overexpressed in the second-and third-generation EGFR-TKIs-resistant cells at the mRNA and protein expression levels. When ANKRD1 was silenced in the EGFR-TKIs-resistant cell lines, afatinib and osimertinib could induce apoptosis of the cell lines. Imatinib could inhibit ANKRD1 expression, resulting in restoration of the sensitivity to afatinib and osimertinib of EGFR-TKI-resistant cells. In EGFR-mutant NSCLC patients, ANKRD1 was overexpressed in the tumor after the failure of EGFR-TKI therapy, especially after long-duration EGFR-TKI treatments. ANKRD1 overexpression which was associated with EMT features and anti-apoptosis, was commonly involved in resistance to second-and third-generation EGFR-TKIs. ANKRD1 inhibition could be a promising therapeutic strategy in EGFR-mutant NSCLC patients.

Inhibition of ZEB1 leads to inversion of metastatic characteristics and restoration of paclitaxel sensitivity of chronic chemoresistant ovarian carcinoma cells

ZEB1, a member of the zinc-finger E-box binding homeobox family, is considered to play a crucial role in cancer progression and metastasis. In the current study, we investigated the role of ZEB1 in metastasis and chronic chemoresistance of epithelial ovarian carcinoma (EOC) cells. Using several EOC and acquired paclitaxel (PTX)-resistant EOC cell lines, we investigated whether silencing ZEB1 led to a reversal of the chemoresistance and metastatic potential in vitro and in vivo. Subsequently, the expression of ZEB1 in EOC tissues and its association with the oncologic outcome were investigated. According to the immunohistochemical staining of EOC tissues, as the positivity of ZEB1 expression was increased, the overall survival of EOC patients became poorer (P = 0.0022 for trend). Additionally, cell migration and invasion were significantly decreased by ZEB1 silencing in both PTX-sensitive and PTX- resistant cells. Although PTX-sensitivity was not changed by silencing ZEB1 in parental EOC cells, the depletion of ZEB1 made the PTX-resistant EOC cells more sensitive to PTX treatment. In an animal model, mice injected with ZEB1-silencing PTX-resistant cells survived for longer than the control cell-injected mice. Although the intravenous injection of PTX did not affect the tumor weight of shCtrl cells, the tumor weight of shZEB1 cells was significantly reduced by PTX treatment. The current data indicate the possible involvement of ZEB1 in the metastasis and paclitaxel resistance of EOC, and suggest that targeting this molecule may reverse the malignant potential and improve the oncologic outcome for EOC patients.

The H19-PEG10/IGF2BP3 axis promotes gastric cancer progression in patients with high lymph node ratios

We previously demonstrated that the lymph node ratio (LNR) is a prognostic factor associated with EGFR expression, among first priority genes amplified or overexpressed in cancer. Here, we investigated the associations between high LNR and second, third, and fourth priority genes. We performed mRNA expression microarray analysis of tumor tissue from patients with stage III gastric cancer and high or low LNRs. Candidate high LNR-associated genes were further evaluated in 39 patients with stage III gastric cancer. The functional relevance of these genes was evaluated in gastric cancer cell lines. We focused on five genes: H19,PEG10, IGF2BP3, CD177, and PGA3. H19 and PEG10 were confirmed as high LNR-associated genes. H19, PEG10, and IGF2BP3 were found to promote each other’s expression. Knocking down H19 or PEG10 using RNAi decreased cell proliferation, invasion, anchorage-independent growth, and chemoresistance. These genes had a mutual relationship in MKN7 cells. H19 knockdown decreased expression of epithelial-mesenchymal transition-associated genes in MKN74 cells to suppress transformation. Thus, H19 promotes epithelial-mesenchymal transition in gastric cancer and is a potential therapeutic target.

Rab25 GTPase: Functional roles in cancer

Rab25, a small GTPase belongs to the Rab protein family, has a pivotal role in cancer pathophysiology. Rab25 governs cell-surface receptors recycling and cellular signaling pathways activation, allowing it to control a diverse range of cellular functions, including cell proliferation, cell motility and cell death. Aberrant expression of Rab25 was linked to cancer development. Majority of research findings revealed that Rab25 is an oncogene. Elevated expression of Rab25 was correlated with poor prognosis and aggressiveness of renal, lung, breast, ovarian and other cancers. However, tumor suppressor function of Rab25 was reported in several cancers, such as colorectal cancer, indicating the tumor type-specific function of Rab25. In this review, we recapitulate the current knowledge of Rab25 in cancer development and therapy.

Central Role of CEMIP in Tumorigenesis and Its Potential as Therapeutic Target

CEMIP (KIAA1199) was identified as migratory indicator protein which had been crudely studied in the last decade. Firstly its mutation site was reported to cause hearing loss due to the folding change of protein structure, meanwhile the over-expression of CEMIP referred to dreadful invasion and uncontrolled proliferation of tumor with distant metastasis, dedifferentiation, and limited survival opportunity of patients. Especially, over-expressed CEMIP also protected malignant tumor from strict microenvironment in hypoxia, low glucose and cracked barrier, leading to enhanced adaptability of tumor by stimulating the Wnt, EGFR, FGFR pathway. Here, we intend to elaborate the clinical function and dysregulation of CEMIP under the tumorous circumstance since CEMIP plays an important role in cytokine pathway and its over-expression in tumors provide a novel target for individual therapy. Targeting CEMIP would thereby dysregulate the cytokine pathway which would in turn, decide the growth and death of the vicious tumour cells.

High Rab25 expression associates with Ki67/TP53/CD133/VEGFR expression predicts poor prognosis in gastric cancer

Rab25 belongs to Rab GTPases which regulating vesicle trafficking of various extracellular and intracellular resources. Aberrant high Rab25 expression is closely linked to cancer development including gastric cancer. However, the underlying mechanism of Ras25 in gastric cancer is still unclear. In this study, we determined to investigate the potential association between Rab25 and four tumor markers, including Ki67 (a well-known hallmarker of tumor proliferation), TP53 (tumor p53, a master tumor regulator associated with cell apoptosis), CD133 (a common cancer stem cell marker) and VEGFR (Vascular endothelial growth factor receptor, an efficient therapy target for gastric cancer). The results indicated that Rab25 expression in both cytoplasm and nucleus was significantly higher in gastric cancer tissues than para-carcinoma tissues. High Rab25 nucleus expression was positively associated with distant metastasis (M stage) and clinical (cTNM) stage, while Rab25 nucleus expression correlated with M stage, cTNM stage and regional lymph metastasis stage (N stage). Survival analysis revealed that high Rab25 cytoplasm/nucleus expression predicted shorter overall survival time of patients with gastric cancer. Rab25 expression was significantly associated with Ki67 expression, TP53 expression, CD133 expressionand VEGFR expression in gastric cancer. In conclusion, our results indicated that Rab25 behaved as an oncogene in gastric cancer related to Ki67/TP53/CD133/VEGFR expression and suggested Rab25 to be a prognostic marker.

ZEB1 Mediates Drug Resistance and EMT in p300-Deficient CRC

We discuss the hypothesis that ZEB1-Wnt-p300 signaling integrates epithelial to mesenchymal transition (EMT) and resistance to histone deacetylase inhibitors (HDACis) in colorectal cancer (CRC) cells. The HDACi butyrate, derived from dietary fiber, has been linked to CRC prevention, and other HDACis have been proposed as therapeutic agents against CRC. We have previously discussed that resistance to butyrate likely contributes to colonic carcinogenesis, and we have demonstrated that butyrate resistance leads to cross-resistance to cancer therapeutic HDACis. Deregulated Wnt signaling is the major initiating event in most CRC cases. One mechanism whereby butyrate and other HDACis exert their anti-CRC effects is via Wnt signaling hyperactivation, which promotes CRC cell apoptosis. The histone acetylases (HATs) CBP and p300 are mediators of Wnt transcriptional activity, and play divergent roles in the downstream consequences of Wnt signaling. CBP-mediated Wnt signaling is associated with cell proliferation and stem cell maintenance; whereas, p300-mediated Wnt activity is associated with differentiation. We have found that CBP and p300 differentially affect the ability of butyrate to influence Wnt signaling, apoptosis, and proliferation. ZEB1 is a Wnt signaling-targeted gene, whose product is a transcription factor expressed at the invasive front of carcinomas where it promotes malignant progression and EMT. ZEB1 is typically a transcriptional repressor; however, when associated with p300, ZEB1 enhances transcription. These changes in ZEB1 activity likely affect the cancer cell phenotype. ZEB1 has been shown to promote resistance to chemotherapeutic agents, and expression of ZEB1 is upregulated in butyrate-resistant CRC cells that lack p300 expression. Since the expression of ZEB1 correlates with poor outcomes in cancer, ZEB represents a relevant therapeutic target. Here we propose that targeting the signaling network established by ZEB1, Wnt signaling, and p300 signaling can reverse HDACi resistance and inhibit EMT.

Roles and Regulation of Epithelial Splicing Regulatory Proteins 1 and 2 in Epithelial-Mesenchymal Transition

The transformation of polarized epithelial cells into cells with mesenchymal characteristics by the morphogenetic process of epithelial-mesenchymal transition (EMT) is a well-characterized process essential for embryonic development and associated with cancer progression. EMT is a program driven by changes in gene expression induced by several EMT-specific transcription factors, which inhibit the expression of cell-cell adhesion proteins and other epithelial markers, causing a characteristic loss of cell-cell adhesion, a switch to mesenchymal cell morphology, and increased migratory capabilities. Recently, it has become apparent that in addition to these transcriptionally regulated changes, EMT may also be regulated posttranscriptionally, that is, by alternative splicing. Specifically, the epithelial splicing regulatory proteins 1 and 2 (ESRP1 and ESRP2) have been described as epithelial-specific splicing master regulators specifically involved in EMT-associated alternative splicing. Here, we discuss the regulation of ESRP activity, as well as the evidence supporting a causal role of ESRPs in EMT.