Differentiation-associated genes regulated by c-Jun and decreased in the progression of esophageal squamous cell carcinoma

Stage II oesophageal carcinoma: peril in disguise associated with cellular reprogramming and oncogenesis regulated by pseudogenes

INTRODUCTION

Pseudogenes have been implicated for their role in regulating cellular differentiation and organismal development. However, their role in promoting cancer-associated differentiation has not been well-studied. This study explores the tumour landscape of oesophageal carcinoma to identify pseudogenes that may regulate events of differentiation to promote oncogenic transformation.

MATERIALS AND METHOD

De-regulated differentiation-associated pseudogenes were identified using DeSeq2 followed by 'InteractiVenn' analysis to identify their expression pattern. Gene expression dependent and independent enrichment analyses were performed with GSEA and ShinyGO, respectively, followed by quantification of cellular reprogramming, extent of differentiation and pleiotropy using three unique metrics. Stage-specific gene regulatory networks using Bayesian Network Splitting Average were generated, followed by network topology analysis. MEME, STREME and Tomtom were employed to identify transcription factors and miRNAs that play a regulatory role downstream of pseudogenes to initiate cellular reprogramming and further promote oncogenic transformation. The patient samples were stratified based on the expression pattern of pseudogenes, followed by GSEA, mutation analysis and survival analysis using GSEA, MAF and 'survminer', respectively.

RESULTS

Pseudogenes display a unique stage-wise expression pattern that characterizes stage II (SII) ESCA with a high rate of cellular reprogramming, degree of differentiation and pleiotropy. Gene regulatory network and associated topology indicate high robustness, thus validating high pleiotropy observed for SII. Pseudogene-regulated expression of SOX2, FEV, PRRX1 and TFAP2A in SII may modulate cellular reprogramming and promote oncogenesis. Additionally, patient stratification-based mutational analysis in SII signifies APOBEC3A (A3A) as a potential hallmark of homeostatic mutational events of reprogrammed cells which in addition to de-regulated APOBEC3G leads to distinct events of hypermutations. Further enrichment analysis for both cohorts revealed the critical role of combinatorial expression of pseudogenes in cellular reprogramming. Finally, survival analysis reveals distinct genes that promote poor prognosis in SII ESCA and patient-stratified cohorts, thus providing valuable prognostic bio-markers along with markers of differentiation and oncogenesis for distinct landscapes of pseudogene expression.

CONCLUSION

Pseudogenes associated with the events of differentiation potentially aid in the initiation of cellular reprogramming to facilitate oncogenic transformation, especially during SII ESCA. Despite a better overall survival of SII, patient stratification reveals combinatorial de-regulation of pseudogenes as a notable marker for a high degree of cellular differentiation with a unique mutational landscape.

The potential mechanism of Guizhi Fuling Wan effect in the treatment of cervical squamous cell carcinoma: A bioinformatics analysis investigation

As a global malignancy with high mortality rate, targeted drug development for Uterine Cervical Neoplasms is an important direction. The traditional formula Guizhi Fuling Wan (GFW) is widely used in gynecological diseases. However, its potential mechanism of action remains to be discovered. We retrieved GFW and cervical squamous cell carcinoma (CSCC) targets from public databases. The protein-protein interaction network was obtained by string computational analysis and imported Cytoscape_v3.9.0 to obtain the core network and the top 10 Hub genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were used for enrichment analysis of the core network, and then molecular docking to verify whether the selected signaling pathway binds well to the core node. Finally, clinical prognostic analysis and expression differences of Hub genes were validated using the Cancer Genome Atlas database and R language. Our search yielded 152 common targets for GFW and CSCC. The interleukin-17 signaling pathway, tumor necrosis factor signaling pathway, and Toll-like signaling pathway were then selected for further molecular docking from the hub genes enrichment analysis results, which showed good binding. Among the Hub genes, JUN, VEGFA, IL1B, and EGF had a poor prognosis for CSCC. In conclusion, this study illustrates that GFW can have adjuvant therapeutic effects on CSCC through multiple targets and multiple pathways, providing a basis for further research.

Network and pathway-based analysis of genes associated with esophageal squamous cell carcinoma

Background

Although diagnostic methods and treatments have improved over the last few years, the 5-year survival rate of esophageal squamous cell carcinoma (ESCC) patients remains generally poor. The development of high-throughput technology has facilitated great achievements in localization of ESCC-related genes. To take a further step toward a thorough understanding of ESCC at a molecular level, the potential pathogenesis of ESCC needs to be deciphered.

Methods

The interaction of ESCC-related genes was explored by collecting genes associated with ESCC and then performing gene enrichment assays, pathway enrichment assays, pathway crosstalk analysis, and extraction of ESCC-specific subnetwork to describe the relevant biochemical processes.

Results

Through Gene Ontology (GO) enrichment analysis, many molecular functions related to response to chemical, cellular response to stimulus, and cell proliferation were found to be significantly enriched in ESCC-related genes. The results of pathway and pathway crosstalk analysis showed that pathways associated with multiple malignant tumors, the immune system, and metabolic processes were significantly enriched in ESCC-related genes. Through the analysis of specific subnetworks, we obtained some novel ESCC-related potential genes, such as MUC13, GSTO1, FIN, GRB2, CDC25C, and others.

Conclusions

The molecular mechanism of ESCC is extremely complex. Some inducing factors change the expression status of many genes. The abnormal expression of genes mediates the biological processes involved in immunity and metabolism, apoptosis, and cell proliferation, leading to the occurrence of tumors. The genes MUC13, RYK, and FIN may be potential prognostic indicators of ESCC; GRB2 and CDC25C may be potential targets of ESCC in proliferation. Our work may provide valuable information for further understanding the molecular mechanisms for the development of ESCC.

Targeting the SOX2/PARP1 complex to intervene in the growth of esophageal squamous cell carcinoma

Elevated SOX2 protein levels are closely correlated with the increased incidence of esophageal squamous cell carcinoma (ESCC). However, establishing effective target measures for ESCC treatments continue to be researched. It has been previously proposed that SOX2 represents a potential therapeutic target for ESCC. Here, we found that the enzyme Poly(ADP-Ribose) polymerase 1 (PARP1) enriched in ESCCs interact with SOX2. Inhibition of PARP1 with 3-aminobenzamide (3-ABA) or shRNA knockdown reduced the proliferation of ESCCs, accompanied by decreased protein levels of SOX2. RNA sequencing demonstrated that PARP1 inhibition affected multiple signaling pathways involved in cancer cell proliferation. Additionally, 3-ABA synergistically suppressed the growth of ESCC cells when combined with cisplatin, and metformin potentiated the suppressive effect of 3-ABA on ESCC cell growth. Together these findings suggest that targeting SOX2 binding partner PARP1 provides a possible avenue to treat patients with high levels of SOX2.

FGFR2 maintains cancer cell differentiation via AKT signaling in esophageal squamous cell carcinoma

Fibroblast growth factors (FGFs) and their receptors (FGFRs) are important for signaling to maintain cancer stem-like cells (CSCs) in esophageal squamous cell carcinoma (ESCC). However, which FGF receptor, 1, 2, 3, 4, and L1, is essential or whether FGFRs have distinct different roles in ESCC-CSCs is still in question. This study shows that FGFR2, particularly the IIIb isoform, is highly expressed in non-CSCs. Non-CSCs have an epithelial phenotype, and such cells are more differentiated in ESCC. Further, FGFR2 induces keratinocyte differentiation through AKT but not MAPK signaling and diminishes CSC populations. Conversely, knockdown of FGFR2 induces epithelial-mesenchymal transition (EMT) and enriches CSC populations in ESCC. Finally, data analysis using The Cancer Genome Atlas (TCGA) dataset shows that expression of FGFR2 significantly correlated with cancer cell differentiation in clinical ESCC samples. The present study shows that each FGFR has a distinct role and FGFR2-AKT signaling is a key driver of keratinocyte differentiation in ESCC. Activation of FGFR2-AKT signaling could be a future therapeutic option targeting CSC in ESCC.

YAP-TEAD up-regulates IRS2 expression to induce and deteriorate oesophageal cancer

Oesophageal cancer (EC) represents a significant cause of cancer worldwide. Yes‐associated protein (YAP) is reported to correlate with the initiation of multiple cancers including EC, but the underlying mechanism remains elusive. The current study aimed to investigate the molecular mechanism of YAP‐TEAD in the occurrence and progression of EC. EC tissues and cells were obtained, followed by determination of the expression of YAP, c‐Jun, pc‐Jun and IRS2. The effect of YAP‐TEAD on the biological EC cell processes was explored through gain‐ and loss‐of‐function approaches. The interaction between YAP and TEAD was detected by co‐immunoprecipitation. The binding of TEAD to the c‐Jun promoter was determined using chromatin immunoprecipitation. Tumour formation in the nude mice was detected in order to ascertain the effect of YAP and IRS2 in vivo. We found elevated YAP in the EC tissues and cells. YAP silencing led to a decrease in EC cell proliferation, invasion and sphere formation. YAP‐TEAD complex bound to the promotor of c‐Jun, and c‐Jun led to an increase in the expression of IRS2 through the JNK/c‐Jun pathway. Additionally, pc‐Jun and phosphorylated JNK were localized in the nuclear in addition to displaying enhanced expression in the EC tissues. IRS2 overexpression negated the inhibition of cell proliferation, invasion and sphere formation triggering YAP silencing. YAP up‐regulated IRS2 and aggravated EC in vivo. Taken together, YAP‐TEAD activates the JNK/c‐Jun pathway to up‐regulate IRS2, ultimately promoting EC progression. Therefore, YAP‐TEAD inhibition could be a promising therapeutic approach for EC treatment.

Downregulation of HDAC3 by ginsenoside Rg3 inhibits epithelial-mesenchymal transition of cutaneous squamous cell carcinoma through c-Jun acetylation

The metastatic rate of human cutaneous squamous cell carcinoma (CSCC) has increased in recent years. Despite the current advances in therapies, effective treatments remain lacking. Ginsenoside 20(R)-Rg3 is an effective antitumor monomer extracted from ginseng, but the role of Rg3 in CSCC remains unknown. It has been reported that aberrantly elevated histone deacetylase 3 (HDAC3) is involved in tumor malignancy in multiple malignant tumors. However, the effects of HDAC3 on the regulation of c-Jun acetylation in tumor epithelial-mesenchymal transition (EMT) and migration have not been clearly illuminated. In our research, the immunohistochemistry staining results of skin tissue microarrays showed that HDAC3 staining was increased in CSCC compared with the normal dermal tissue. Then, we found that Rg3 treatment (25 and 50 μg/ml) inhibited CSCC cell (A431 and SCC12 cells) EMT through increasing E-cadherin and decreasing N-cadherin, vimentin, and Snail expression. Wound-healing and transwell assays showed that Rg3 could inhibit migration. Meanwhile, Rg3 significantly downregulated the expression of HDAC3 in CSCC cells as detected by real-time quantitative PCR, western blot, and immunofluorescence. Importantly, c-Jun acetylation was increased by the downregulation of HDAC3 with HDAC3 shRNA, and the downregulation was associated with CSCC cell EMT inhibition. Collectively, our results showed that downregulation of HDAC3 by Rg3 or shHDAC3 treatment resulted in c-Jun acetylation, which in turn inhibited CSCC cell EMT. These results indicate that HDAC3 could potentially serve as a therapeutic target therapeutic target for CSCC. Rg3 is an attractive and efficient agent that has oncotherapeutic effects and requires further investigation.

MEIS1 knockdown may promote differentiation of esophageal squamous carcinoma cell line KYSE-30

Background

MEIS1 (Myeloid ecotropic viral integration site 1), as a homeobox (HOX) transcription factor, has a dual function in different types of cancer. Although numerous roles are proposed for MEIS1 in differentiation, stem cell function, gastrointestinal development and tumorigenesis, the involved molecular mechanisms are poor understood. Our aim in this study was to elucidate the functional correlation between MEIS1, as regulator of differentiation process, and the involved genes in cell differentiation in human esophageal squamous carcinoma (ESC) cell line KYSE‐30.

Methods

The KYSE‐30 cells were transduced using recombinant retroviral particles containing specific shRNA sequence against MEIS1 to knockdown MEIS1 gene expression. Following RNA extraction and cDNA synthesis, mRNA expression of MEIS1 and the selected genes including TWIST1, EGF, CDX2, and KRT4 was examined using relative comparative real‐time PCR.

Results

Retroviral transduction caused a significant underexpression of MEIS1 in GFP‐hMEIS1 compared to control GFP cells approximately 5.5‐fold. While knockdown of MEIS1 expression caused a significant decrease in EGF and TWIST1 mRNA expression, nearly ‐8‐ and ‐12‐fold respectively, it caused a significant increase in mRNA expression of differentiation markers including KRT4 and CDX2, approximately 34‐ and 1.14‐fold, correspondingly.

Conclusion

MEIS1 gene silencing in KYSE‐30 cells increased expression of epithelial markers and decreased expression of epithelial‐mesenchymal transition (EMT) marker TWIST1. It may highlight the role of MEIS1 in differentiation process of KYSE‐30 cells. These results may confirm that MEIS1 silencing promotes differentiation and decreases EMT capability of ESC cell line KYSE‐30.

Fine particulate matter (PM2.5) inhibits ciliogenesis by increasing SPRR3 expression via c-Jun activation in RPE cells and skin keratinocytes

Exposure to fine particulate matter (PM) with diameter <2.5 µm (PM2.5) causes epithelium injury and endothelial dysfunction. Primary cilia are sensory organelles that transmit extracellular signals into intracellular biochemical responses and have roles in physiology. To date, there have been no studies investigating whether PM2.5 affects primary cilia in skin. We addressed this in the present study using normal human epidermal keratinocytes (NHEKs) and retinal pigment epithelium (RPE) cells. We found that formation of primary cilium is increased in differentiated NHEKs. However, treatment with PM2.5 blocked increased ciliogenesis in NHEKs and RPE cells. Furthermore, PM2.5 transcriptionally upregulated small proline rich protein 3 (SPRR3) expression by activating c-Jun, and ectopic expression of SPRR3 inhibits suppressed the ciliogenesis. Accordingly, treatment with c-Jun activator (anisomycin) induced SPRR3 expression, whereas the inhibitor (SP600125) recovered the ciliated cells and cilium length in PM2.5-treated cells. Moreover, c-Jun inhibitor suppressed upregulation of SPRR3 in PM2.5-treated cells. Taken together, our finding suggested that PM2.5 inhibits ciliogenesis by increasing SPRR3 expression via c-Jun activation in RPE cells and keratinocytes.

OTUB1 promotes esophageal squamous cell carcinoma metastasis through modulating Snail stability

Snail is a key regulator of epithelial-mesenchymal transition (EMT) and plays an important role in tumor progression and metastasis. Snail is rapidly degraded in the cells and its protein level is critically controlled. Although several E3 ligases regulating Snail degradation have been defined, the deubiquitinases (DUBs) responsible for Snail deubiquitination are less studied. We identified ovarian tumor domain-containing ubiquitin aldehyde binding protein 1 (OTUB1) as a DUB that stabilizes Snail through preventing its ubiquitination and proteasomal degradation. Functionally, OTUB1 facilitates metastasis of esophageal squamous cell carcinoma (ESCC) through promoting Snail protein stability. Moreover, OTUB1 is highly expressed in ESCC and higher expression of OTUB1 predicts poor prognosis. These findings suggest that OTUB1 is an essential regulator of Snail and plays a critical role in facilitating esophageal cancer progression.

C-Jun expression in lichen planus, psoriasis, and cutaneous squamous cell carcinoma, an immunohistochemical study

The AP-1 transcription factor complex is a key player in regulating inflammatory processes, cell proliferation, differentiation, and cell transformation. The aim of the present study is to investigate C-Jun (one of AP-1complex) expression and its proliferative role in skin samples of lichen planus, psoriasis as common inflammatory skin diseases and squamous cell carcinoma using immunohistochemical method. The present study was carried out on skin biopsies of 15 psoriatic patients, 15 lichen planus patients, 15 SCC, and 15 normal skin biopsies. Nuclear expression of C-Jun was detected in basal and few suprabasal layers of epidermis of normal skin. C-Jun was expressed in the whole epidermal layers of both psoriasis (14/15) and lichen planus (15/15) in addition to its expression in lymphocytic infiltrate in the latter in about half of cases (8/15). C-Jun was also expressed in 93.3% (14/15) of SCC in a percentage lower than that of psoriasis, lichen planus, and normal skin. The percentage of C-Jun expression in SCC was significantly associated with an early stage (p = 0.000), free surgical margins (p = 0.022), and small tumour size (p = 0.003).

CONCLUSIONS

The marked reduction of C-Jun in SCC in comparison to normal skin and inflammatory skin dermatoses may refer to its tumour suppressor activity. C-Jun expression in SCC carries favourable prognosis. Absence of significant association between C-Jun and Ki-67 either in SCC or inflammatory skin diseases indicates that it does not affect proliferative capacity of cells.

Clinical significance of serum cathepsin B and cystatin C levels and their ratio in the prognosis of patients with esophageal cancer

OBJECTIVE

The main purpose of this study was to analyze the serum cathepsin B (CTSB) and cystatin C (CysC) levels in patients with esophageal carcinoma and their correlation with the clinical indices and prognosis.

METHODS

The serum levels of CTSB and CysC from 56 patients with esophageal carcinoma and 30 healthy donors were determined preoperatively by using enzyme-linked immunosor-bent assay. The correlation between CTSB and CysC was evaluated by Spearman correlation coefficient test. Kaplan-Meier survival curves were plotted, while the survival rates were compared using the log-rank test. Univariate and multivariate analyses of prognostic factors for survival were performed using the Cox proportional hazard regression model with a 95% confidence interval.

RESULTS

CTSB (38.35±4.3 ng/mL) and CysC (703.96±23.6 ng/mL) levels were significantly higher in the sera of the patients than in controls. A significant correlation was observed between CTSB and CysC (r=0.754, P<0.001). The levels of CTSB and CysC/CTSB in the patient serum significantly correlated with the T status. CysC/CTSB ratio was also found to be significantly correlated with lymph node metastasis. None of the parameters were observed to be related to CysC, including age, gender, pathologic type, tumor differentiation and tumor invasion depth. Kaplan-Meier analysis showed that patients with higher levels of CysC/CTSB and negative lymph node metastasis experienced significantly longer overall survival time, whereas patients with higher CSTB levels tended to live shorter, although the difference was not statistically significant (P=0.081).

CONCLUSION

Serum CTSB and CysC levels are of diagnostic significance in esophageal cancer. The ratio of serum CysC/CTSB is prognostic for the survival of esophageal carcinoma patients.

FBXO32 suppresses breast cancer tumorigenesis through targeting KLF4 to proteasomal degradation

Krüppel-like factor 4 (KLF4, GKLF) is a zinc-finger transcription factor involved in a large variety of cellular processes, including apoptosis, cell cycle progression, as well as stem cell renewal. KLF4 is critical for cell fate decision and has an ambivalent role in tumorigenesis. Emerging data keep reminding us that KLF4 dysregulation either facilitates or impedes tumor progression, making it important to clarify the regulating network of KLF4. Like most transcription factors, KLF4 has a rather short half-life within the cell and its turnover must be carefully orchestrated by ubiquitination and ubiquitin-proteasome system. To better understand the mechanism of KLF4 ubiquitination, we performed a genome-wide screen of E3 ligase small interfering RNA library based on western blot and identified SCF-FBXO32 to be a new E3 ligase, which is responsible for KLF4 ubiquitination and degradation. The F-box domain is critical for FBXO32-dependent KLF4 ubiquitination and degradation. Furthermore, we demonstrated that FBXO32 physically interacts with the N-terminus (1-60 aa) of KLF4 via its C-terminus (228-355 aa) and directly targets KLF4 for ubiquitination and degradation. We also found out that p38 mitogen-activated protein kinase pathway may be implicated in FBXO32-mediated ubiquitination of KLF4, as p38 kinase inhibitor coincidently abrogates endogenous KLF4 ubiquitination and degradation, as well as FBXO32-dependent exogenous KLF4 ubiquitination and degradation. Finally, FBXO32 inhibits colony formation in vitro and primary tumor initiation and growth in vivo through targeting KLF4 into degradation. Our findings thus further elucidate the tumor-suppressive function of FBXO32 in breast cancer. These results expand our understanding of the posttranslational modification of KLF4 and of its role in breast cancer development and provide a potential target for diagnosis and therapeutic treatment of breast cancer.

Inhibitor of Differentiation/DNA Binding 1 (ID1) Inhibits Etoposide-induced Apoptosis in a c-Jun/c-Fos-dependent Manner

ID1 (inhibitor of differentiation/DNA binding 1) acts an important role in metastasis, tumorigenesis, and maintenance of cell viability. It has been shown that the up-regulation of ID1 is correlated with poor prognosis and the resistance to chemotherapy of human cancers. However, the underlying molecular mechanism remains elusive. Here, we determined for the first time that up-regulating ID1 upon etoposide activation was mediated through AP-1 binding sites within theID1promoter and confirmed that ID1 enhanced cell resistance to DNA damage-induced apoptosis in esophageal squamous cell carcinoma cells. Ablation of c-Jun/c-Fos or ID1 expression enhanced etoposide-mediated apoptosis through increasing activity of caspase 3 and PARP cleavage. Moreover, c-Jun/c-Fos and ID1 were positively correlated in human cancers. More importantly, simultaneous high expression of ID1 and c-Jun or c-Fos was correlated with poor survival in cancer patients. Collectively, we demonstrate the importance of c-Jun/c-Fos-ID1 signaling pathway in chemoresistance of esophageal cancer cells and provide considerable insight into understanding the underlying molecular mechanisms in esophageal squamous cell carcinoma cell biology.

RANK overexpression as a novel esophageal cancer marker: validated immunohistochemical analysis of two different ethnicities

This study aimed to evaluate the receptor activator of nuclear factor-κB (RANK) expression statuses of esophageal squamous cell carcinoma (ESCC) patients, high-grade intraepithelial neoplasia (HGIN), low-grade intraepithelial neoplasia (LGIN), and normal esophageal tissues (NETs) in Chinese Han and Kazakh ethnic, as well as the correlation of RANK expression with clinicopathological characteristics. RANK immunohistochemical analysis was conducted to investigate the expression of RANK in 113 ESCC, 36 HGIN, 63 LGIN, and 98 NETs from Han ethnic patients and in 196 ESCC and 76 NETs from Kazakh ethnic patients. The associations of RANK expression with ethnic and clinicopathological characteristics were examined using χ(2)-test. Upregulated RANK expression was detected in both Han and Kazakh ethnic ESCC tissues, compared with NETs (P = 1.11 × 10(-5), 0.001, respectively). RANK expression was significantly increased during malignant transformation from normal epithelium into LGIN (P = 2.84 × 10(-7)) and HGIN (P = 7.83 × 10(-6)) tissues in Han ethnic patients. The increased expression of RANK also correlated with lymph node metastasis in Kazakh ethnic ESCC patients (P = 0.019). By contrast, no significant correlation existed between RANK expression and clinicopathological characteristics of Han ethnic ESCC patients. Furthermore, Kaplan-Meier survival analysis showed that ESCC patients with higher expression of RANK protein had significantly worse prognosis than ESCC patients with low or no expression (P = 0.001). In conclusion, this study is the first to identify RANK overexpression as a novel esophageal cancer marker in both Kazakh and Han ethnic ESCC patients. The results support the association of RANK with ESCC across ethnicities. In summary, RANK could be a therapeutic target in ESCC patients.