Prognostic and Clinicopathological Significance of Transducer-Like Enhancer of Split 1 Expression in Gastric Cancer

Identification of potential biomarkers for papillary thyroid carcinoma by comprehensive bioinformatics analysis

To perform bioinformatics analysis on the papillary thyroid carcinoma (PTC) gene chip dataset to explore new biological markers for PTC. The gene expression profiles of GSE3467 and GSE6004 chip data were collected by GEO2R, and the differentially expressed genes (DEGs) were selected for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Protein-protein interaction (PPI) relationship analysis was achieved using STRING, and the hub genes were obtained using the Cytoscape software. GEPIA was used to validate the expressions of the hub genes in the normal and tumor tissues and to conduct survival analyses. Pertinent genetic pathology results were fetched using the HPA database. Finally, the key genes were clinically verified by reverse transcription-polymerase chain reaction. 97 genes were jointly up-regulated and 107 genes were jointly down-regulated in GSE3467 and GSE6004. GO function enrichment analysis revealed that the DEGs were involved in the regulation of calcium ion transport into cytosol, integrin binding, and cell adhesion molecule binding. KEGG pathway enrichment analysis indicated that the DEGs were chiefly associated with thyroid cancer and non-small cell lung cancer. According to the PPI network, 30 key target genes were identified. Only the expressions of ANK2, TLE1, and TCF4 matched between the normal and tumor tissues, and were associated with disease prognosis. When compared with the normal thyroid tissues, the protein and mRNA expressions of ANK2, TLE1, and TCF4 were down-regulated in PTC. Significant differences exist in overall gene expression between the thyroid tissues of patients with PTC and those of healthy people. Furthermore, the differential genes ANK2, TLE1, and TCF4 are expected to be reliable molecular markers for the mechanism study and diagnosis of PTC.

The prognostic role of the Transducin-like Enhancer of split protein family in lung adenocarcinoma

Background

Lung cancer claims more lives than any other cancer worldwide. Lung adenocarcinoma (LUAD) accounts for approximately 40% of all lung cancers. Members of the Transducin-like Enhancer of split (TLE) protein family repress transcription through multiple mechanisms; however, their prognostic value in LUAD is still unclear.

Methods

A dataset from The Cancer Genome Atlas was used to analyze the relationship between the expression of TLE family members and outcomes of LUAD. The expression of TLE family members in 59 normal and 513 tumor samples in the TCGA dataset was selected. For paired analysis, 57 normal and 57 tumor paired tissues were selected. Gene Ontology (GO) term and Reactome pathway enrichment analyses of the TLE family members were performed. Progression-free survival (PFS) and overall survival (OS) served as endpoints in this study. All statistical analyses were performed with R 3.6.0.

Results

The expression levels of TLE family proteins differed between 59 normal and 513 tumor samples. High TLE1 and low TLE2 levels were associated with poor progression-free and OS (all P<0.050). Multivariate analysis demonstrated that high TLE1 expression and low TLE2 expression were independent risk factors for a poor outcome in LUAD. Moreover, the combined expression of these two proteins was a good tool for prognostication.

Conclusions

High TLE1 expression and low TLE2 are independent adverse prognostic factors in LUAD and can serve as prognostic biomarkers.

Prognostic Value of TLE1 Gene Expression in Patients with T-cell Acute Lymphoblastic Leukemia

Background:

Transducin-like enhancer of split 1 (TLE1( is a member of the TLE family of transcriptional co-repressors that control the transcription of a wide range of genes. The aim of this study was to evaluate the prognostic role of TLE1 gene expression in patients with T-cell acute lymphoblastic leukemia (T-ALL).

Method:

This study was conducted on 97 newly diagnosed T-ALL patients admitted to the Mansoura University oncology center (59 males and 38 females) with median age (33 years) in addition to 102 apparently healthy individuals served as a control group. TLE1 gene expression was measured in both patients and control groups by real time – PCR. The calculation of relative gene expression was done using the ΔΔCt method.

Results:

TEL1 gene expression was significantly down regulated in T-ALL cases (median 2.83) as compared to controls (median 84.65) (p < 0.001). The low TEL1 gene expression was significantly associated with CNS infiltration, non-remission and higher relapse rate (p< 0.001, 0.001 and 0.023 respectively). Likewise, Low TEL1 gene expression was significantly associated with shorter OS and DFS (P= 0.012 and 0.011 respectively). Furthermore, Low TEL1 gene expression was considered as risk predictor of relapse with OR 3.636(CI.1.422-9.295) (P =0.007); and OR 0.803(CI. 0.609-0.96) (P=0.021) and independent predictor of T-ALL patient’s outcome with OR 0.619 (CI. 0.44-0.872) (P=0.006).

Conclusion:

TLE1 gene expression was significantly down regulated in T-ALL cases as compared with controls. Low TLE1 expression is independent predictor of the T-ALL patient’s outcome.

Gene of the month: TLE 1

TLE 1 is the human homologue belonging to a family of four genes and is located on chromosome 9q21. It consists of 19 exons. Although it does not bind directly to DNA, it acts as a repressor of several signalling pathways via transcription factors. TLE1 protein has several physiological roles in embryogenesis, haematopoiesis, general differentiation, and both neuronal and eye development. Much attention was focused on its expression in the tumour cell nuclei of synovial sarcoma (SS). However, several other soft tissue tumours that do and do not share morphological similarity with SS also display nuclear immunoreactivity for TLE1; hence, caution in interpretation is advocated.

lncRNA RASSF8‑AS1 suppresses the progression of laryngeal squamous cell carcinoma via targeting the miR‑664b‑3p/TLE1 axis

Long non‑coding (lnc)RNAs have been found to play a crucial role in tumor progression. The present study aimed to investigate the association between lncRNA RASSF8‑AS1 and laryngeal squamous cell carcinoma (LSCC) and the underlying mechanisms. Reverse transcription‑quantitative PCR was used to measure the mRNA expression level of RASSF8‑AS1, microRNA(miR)‑664b‑3p and transducin‑like enhancer of split 1 (TLE1) in LSCC. The associations between RASSF8‑AS1 and miR‑664b‑3p, and between miR‑664b‑3p and TLE1 were investigated using a dual luciferase reporter assay, while the former was further verified using an RNA immunoprecipitation (RIP) assay. The association between RASSF8‑AS1 and miR‑664b‑3p on cell biological functions was investigated in vitro using MTS, colony formation and Transwell assays. The RASSF8‑AS1 mRNA expression level was decreased in LSCC cell lines and carcinoma tissues, while overexpression of RASSF8‑AS1 reduced the migration, invasion and proliferation abilities of LSCC cells. Furthermore, luciferase and RIP assays confirmed that RASSF8‑AS1 was a competitive endogenous (ce)RNA by sponging miR‑664b‑3p to activate TLE1. miR‑664b‑3p was negatively modulated by RASSF8‑AS1; however, TLE1 was positively regulated by RASSF8‑AS1. Functionally, RASSF8‑AS1 acted as a ceRNA to upregulate TLE1 by sponging miR‑664b‑3p. In conclusion, the RASSF8‑AS1/miR‑664b‑3p/TLE1 axis acts by suppressing LSCC progression and may provide a novel insight for the molecular mechanism of LSCC.

Transducin-Like Enhancer of Split-1 Inhibits Malignant Behaviors in vitro and Predicts a Better Prognosis in Pancreatic Ductal Adenocarcinoma

Background: Transducin-like enhancer of split-1 (TLE1), a member of the Groucho/TLE family of transcriptional corepressors, has been reported to be involved in the tumorigenesis of various cancers and function as a clinical prognostic indicator. However, the mechanisms and prognostic significance of TLE1 in pancreatic ductal adenocarcinoma (PDAC) have not been elucidated. Methods: In this study, western blot analyses and real-time polymerase chain reaction (RT-PCR) were employed to evaluate the expression of TLE1 and related proteins in PDAC cell lines. Wound healing, transwell migration and invasion, and Cell Counting Kit-8 (CCK-8) assays were used to determine cell line-specific differences in metastasis and proliferation. Flow cytometry was performed for cell cycle detection. RNA sequencing and bioinformatics were undertaken to explore the molecular mechanisms and potential targeted molecules of TLE1. TLE1 expression in tumor and para-tumor tissues was evaluated by tissue microarray-based immunohistochemistry using a semiquantitative method (H-score) in 262 patients with radical PDAC resection. Correlation, Kaplan-Meier survival, univariate, and multivariate analyses were also performed. Results: Our findings showed that TLE1 expression was common in PDAC cell lines. Upregulation of TLE1 inhibited PDAC cell migration, invasion, and proliferation in vitro by delaying the G0/G1 transition. Immunohistochemistry revealed that TLE1 was specifically expressed in the nucleus and at higher levels in tumor tissues compared with para-tumor tissues. Generally, high TLE1 expression was associated with no vascular invasion. In univariate analyses, high TLE1 expression was associated with longer disease-specific survival (DSS) in all patients and in 16 patient subgroups. In multivariate analyses, TLE1 expression was independently associated with DSS in all patients and four patient subgroups. Conclusion: In conclusion, these results suggest that TLE1 has an inhibitory role in PDAC progression and is a favorable prognostic indicator for patients with resectable PDAC.

TLE1 as an indicator of adverse prognosis in pediatric acute lymphoblastic leukemia

PURPOSE

Acute lymphoblastic leukemia (ALL) is the most common type of cancer in children, and despite the high rate of cure (over 80%) it still has a big impact on morbidity and mortality. The Transducin-like enhancer of split 1 (TLE1), a transcriptional corepressor, has been described as dysregulated and recently emerged as a tumor marker in several cancer types, including hematologic malignancies.

METHODS

In the present study TLE1 gene expression was evaluated by RT-qPCR. A total of 60 consecutive pathological ALL samples and 8 normal bone marrow samples were included. Associations between TLE1 levels and clinicopathological features were estimated using Mann-Whitney tests.

RESULTS

TLE1 mRNA levels were significantly diminished in ALL samples when compared to normal counterparts (fold change -1.45, p-value 0.039). Lower TLE1 expression levels were associated with poorer prognostic features such as age at diagnosis (<1 or >9 years-old), absence of the Common Acute Lymphoblastic Leukemia Antigen (CALLA) and high white cell count. Considering immunophenotype, decreased expression of TLE1 was only evident for T-cell ALL, what was validated using gene expression profiling data available in public repositories. No associations with event or overall survival were observed. However, TLE1 expression was statistically different between patients who achieved complete clinical remission (CCR) from those that relapsed or died.

CONCLUSION

These data are of particular interest and give support for a plausible role of TLE1 as a tumor suppressor in T-cell ALL. Moreover, the prognostic value of this corepressor may assist ALL treatment stratification and suggest the need of alternative regimens.

Difference in transducin-like enhancer of split 1 protein expression between basal cell adenomas and basal cell adenocarcinomas - an immunohistochemical study

Background

Basal cell adenoma (BCA) and basal cell adenocarcinoma (BCAC) are benign and malignant, basaloid salivary gland neoplasms, respectively. These tumors show a dual-cell proliferation of inner luminal/ductal cells and outer abluminal/myoepithelial or basal cells. The only difference between them is defined as a malignant morphology such as invasion. Recently, the nuclear expression of β-catenin and a catenin beta-1 (CTNNB1) mutation were found in BCA. Transducin-like enhancer of split 1 (TLE1) belongs to the Groucho/TLE family, and it functions in the “off” state in the Wnt/β-catenin signaling pathway. We hypothesized that if the dysregulation of the Wnt/β-catenin signaling pathway could be attributed to the tumorigenesis of BCA/BCAC, there might be differences in TLE1 expression between BCA and BCAC.

Method

The study included 35 BCA and 4 BCAC cases. We performed immunohistochemistry to detect TLE1 and β-catenin and investigated the catenin beta-1 (CTNNB1) mutational profile among BCA and BCAC cases.

Results

In BCA, the expression of TLE1 was confined to luminal cells of glandular structures, in contrast to the expression of β-catenin in abluminal cells. The BCA cases harbored CTNNB1 gene mutations (12/35). In BCAC, luminal cell staining of TLE1 was identical to BCA in non-invasive areas (4/4) but indistinct in invasive areas (3/4). The BCAC cases were β-catenin positive for abluminal cells in both areas. The BCAC cases had CTNNB1 mutation (2/4) and the laser-captured microdissection allowed the separate collection of infiltrative and non-infiltrative areas to detect the same mutation.

Conclusions

Immunohistochemical analysis for TLE1 can identify BCA and BCAC by luminal cell staining difference, especially indistinct luminal cell expression for TLE1 in invasive areas of BCAC. Moreover, TLE1 can be luminal/ductal cell markers.

Association between PIK3CA alteration and prognosis of gastric cancer patients: a meta-analysis

BACKGROUND

Increasing evidence suggests that dysregulation of phosphatidylinositol-4, 5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) plays an important role in carcinogenesis. However, the relationship between PIK3CA expression and gastric cancer (GC) prognosis remains controversial.

METHODS

We searchedPubMed, Embase, Web of Science, and the Cochrane Library databases for relevant studies up to June 30, 2017. Primary outcomes were hazard ratio (HR), odds ratio (OR), and 95% confidence intervals (CI) for association with overall survival and clinicopathological features.

RESULTS

Eleven studies comprising 2481 GC patients were analyzed. Pooled analysis showed that PIK3CA upregulation was significantly associated with worse overall survival (HR = 1.79, 95% CI 1.42-2.27, p< 0.001) at the protein (HR = 1.94, 95% CI 1.52-2.47, p< 0.001) but not the gene (HR = 1.57, 95% CI 0.92-2.69, p= 0.097) level. PIK3CA gene mutation did not correlate with overall survival (HR = 1.05, 95% CI 0.83-1.34, p= 0.666) but was significantly associated with poor tumor differentiation (OR = 0.37, 95% CI 0.17-0.76, p= 0.011).

CONCLUSION

High PIK3CA protein expression predicted poor prognosis in GC, whereas PIK3CA gene amplification or mutation did not. Moreover, PIK3CA mutation was an indicator of poorly differentiated tumors.

Clinicopathologic and Prognostic Significance of Transducin-Like Enhancer of Split 1 Protein Expression in Invasive Breast Cancer

Purpose

Transducin-like enhancer of split 1 (TLE1) is a member of the TLE family of transcriptional co-repressors that control the transcription of a wide range of genes. We investigated the prognostic significance of TLE1 protein expression in breast cancers by using immunohistochemistry and explored the relationship of TLE1 with clinicopathological parameters.

Methods

Immunohistochemistry was performed on 456 cases of breast cancer tiled on tissue microarrays. The relationship between TLE1 expression in normal breast specimens and ductal carcinoma in situ (DCIS) was also analyzed.

Results

TLE1 was highly expressed in 57 of 456 (12.5%) carcinoma samples. TLE1 was more frequently expressed in DCIS and invasive breast cancers than in normal breast tissue (p=0.002). High expression of TLE1 significantly correlated with negative lymph node (LN) metastasis (p=0.007), high histologic grade (p<0.001), estrogen receptor negativity (p<0.001), progesterone receptor negativity (p<0.001), human epidermal growth factor receptor 2 (HER2) positivity (p<0.001), and high Ki-67 proliferation index (p<0.001). Based on intrinsic subtypes, high TLE1 expression was strongly associated with HER2+ and triple-negative breast cancers (TNBC) (p<0.001). Survival analysis demonstrated no significant association between TLE1 expression and disease-free survival (DFS) (p=0.167) or overall survival (OS) (p=0.286). In subgroup analyses, no correlation was found between TLE1 expression and DFS or OS according to LN status or intrinsic subtype.

Conclusion

High TLE1 expression is significantly associated with the HER2+ and TNBC subtypes. This is the first study documenting immunohistochemical expression of TLE1 in invasive breast cancer and its association with clinicopathological parameters, prognosis, and intrinsic subtype.

TLE1 function and therapeutic potential in cancer

Groucho (Gro)/Transducin-like enhancer of split (TLE) family proteins act as co-repressors of many transcription factors, and are involved in key signaling pathways. TLE1 negatively regulates inflammation and has potential roles in various diseases, including cancer. Previous studies suggest TLE1 could be used as a diagnostic marker and is a possible therapeutic target in various malignancies. It is therefore important to elucidate the mechanisms underlying TLE1 function during cancer initiation and metastasis. In this review, we highlight the functions of TLE1 in cancer and explore targeted approaches for cancer diagnosis and treatment. In particular, we discuss the TLE1 function in pancreatic cancer.