A TERT-CLPTM1 locus polymorphism (rs401681) is associated with EGFR mutation in non-small cell lung cancer

De novo CLPTM1 variants with reduced GABAA R current response in patients with epilepsy

OBJECTIVE

To investigate the clinical features and potential pathogenesis mechanism of de novo CLPTM1 variants associated with epilepsy.

METHODS

Identify de novo genetic variants associated with epilepsy by reanalyzing trio-based whole-exome sequencing data. We analyzed the clinical characteristics of patients with these variants and performed functional in vitro studies in cells expressing mutant complementary DNA for these variants using whole-cell voltage-clamp current recordings and outside-out patch-clamp recordings from transiently transfected human embryonic kidney (HEK) cells.

RESULTS

Two de novo missense variants related to epilepsy were identified in the CLPTM1 gene. Functional studies indicated that CLPTM1-p.R454H and CLPTM1-p.R568Q variants reduced the γ-aminobutyric acid A receptor (GABAA R) current response amplitude recorded under voltage clamp compared to the wild-type receptors. These variants also reduced the charge transfer and altered the time course of desensitization and deactivation following rapid removal of GABA. The surface expression of the GABAA R γ2 subunit from the CLPTM1-p.R568Q group was significantly reduced compared to CLPTM1-WT.

SIGNIFICANCE

This is the first report of functionally relevant variants within the CLPTM1 gene. Patch-clamp recordings showed that these de novo CLPTM1 variants reduce GABAA R currents and charge transfer, which should promote excitation and hypersynchronous activity. This study may provide insights into the molecular mechanisms of the CLPTM1 variants underlying the patients' phenotypes, as well as for exploring potential therapeutic targets for epilepsy.

Prognostic Value of Telomeric Zinc Finger-Associated Protein Expression in Adenocarcinoma and Squamous Cell Carcinoma of Lung

Background and Objectives: Telomeric zinc finger-associated protein (TZAP) is a telomere regulation protein, previously known as ZBTB48. It binds preferentially to elongated telomeres, competing with telomeric repeat factors 1 and 2. TZAP expression may be associated with carcinogenesis, however; this study has not yet been performed in lung cancer. In this study, we examined the clinicopathological and prognostic values of TZAP expression in non-small cell lung cancer (NSCLC). Materials and Methods: Data were collected from The Cancer Genome Atlas. The clinical and prognostic values of TZAP for NSCLC were examined in adenocarcinoma (AD) and squamous cell carcinoma (SCC). Results: TZAP expression significantly increased in NSCLC tissues compared with normal tissues. In AD, TZAP expression was lower in patients with higher T stage (p = 0.005), and was associated with lymph node stage in SCC (p = 0.005). Survival analysis showed shorter disease-free survival in AD patients with lower TZAP expression (p = 0.047). TZAP expression did not have other clinical or prognostic value for AD and SCC. Conclusions: TZAP expression is a potential prognostic marker for NSCLC, especially in patients with AD.

CLPTM1L Is a Novel Putative Oncogene Promoting Tumorigenesis in Oral Squamous Cell Carcinoma

This study aimed to explore the function of CLPTM1L in oral squamous cell carcinoma and mechanism of tumorigenesis. The expression of CLPTM1L was detected by immunohistochemistry. The localization in cells was detected by immunofluorescence. Cell invasion, proliferation, and migration were detected by transwell, CCK-8 and scratch-wound test. The possible characteristics of CLPTM1L were analysed in TCGA, GO, KEGG and String databases. IHC revealed that the expression of CLPTM1L in 92 cases of OSCC tissues was significantly higher (P < 0.01) than 29 cases of normal oral epithelium tissues. The expression of CLPTM1L was significantly higher in oral squamous cell carcinoma in TCGA database. CLPTM1L expression was not significantly correlated with the patients’ clinical parameters. High expression of CLPTM1L was associated with worse prognosis. Cox regression analysis demonstrated that the CLPTM1L expression was the significant risk factor. CLPTM1L was mainly localized in the perinuclear cytoplasm. The vitro studies revealed that the knockdown of CLPTM1L suppressed invasion, proliferation and migration. CLPTM1L related genes were enriched in protein processing in the endoplasmic reticulum, protein folding, endoplasmic reticulum formation, N-glycan biosynthesis, and protein hydroxylation. Highly expressed CLPTM1L may contribute to a poor prognosis and increase invasion, proliferation and migration of oral squamous cell carcinoma. CLPTM1L may play an important role in tumorgenesis and would be a valuable target gene for the treatment of oral squamous cell carcinoma.

CLPTM1L induces estrogen receptor β signaling-mediated radioresistance in non-small cell lung cancer cells

INTRODUCTION

Radioresistance is a major challenge in lung cancer radiotherapy, and new radiosensitizers are urgently needed. Estrogen receptor β (ERβ) is involved in the progression of non-small cell lung cancer (NSCLC), however, the role of ERβ in the response to radiotherapy in lung cancer remains elusive. In the present study, we investigated the mechanism underlying ERβ-mediated transcriptional activation and radioresistance of NSCLC cells.

METHODS

Quantitative real-time PCR, western blot and immunohistochemistry were used to detect the expression of CLPTM1L, ERβ and other target genes. The mechanism of CLPTM1L in modulation of radiosensitivity was investigated by chromatin immunoprecipitation assay, luciferase reporter gene assay, immunofluorescence staining, confocal microscopy, coimmunoprecipitation and GST pull-down assays. The functional role of CLPTM1L was detected by function assays in vitro and in vivo.

RESULTS

CLPTM1L expression was negatively correlated with the radiosensitivity of NSCLC cell lines, and irradiation upregulated CLPTM1L in radioresistant (A549) but not in radiosensitive (H460) NSCLC cells. Meanwhile, IR induced the translocation of CLPTM1L from the cytoplasm into the nucleus in NSCLC cells. Moreover, CLPTM1L induced radioresistance in NSCLC cells. iTRAQ-based analysis and cDNA microarray identified irradiation-related genes commonly targeted by CLPTM1L and ERβ, and CLPTM1L upregulated ERβ-induced genes CDC25A, c-Jun, and BCL2. Mechanistically, CLPTM1L coactivated ERβ by directly interacting with ERβ through the LXXLL NR (nuclear receptor)-binding motif. Functionally, ERβ silencing was sufficient to block CLPTM1L-enhanced radioresistance of NSCLC cells in vitro. CLPTM1L shRNA treatment in combination with irradiation significantly inhibited cancer cell growth in NSCLC xenograft tumors in vivo.

CONCLUSIONS

The present results indicate that CLPTM1L acts as a critical coactivator of ERβ to promote the transcription of its target genes and induce radioresistance of NSCLC cells, suggesting a new target for radiosensitization in NSCLC therapy. Video Abstract.

Polymorphisms of the TERT-CLPTM1L Gene Are Associated with Pharynx-Larynx Cancer

Pharynx-larynx cancer is a complex malignant tumor with the sixth-highest morbidity and mortality rate worldwide. The telomerase reverse transcriptase TERT-CLPTM1L gene, located on chromosome 5p15.33, plays a key role in the occurrence and progression of various cancer. The purpose of this hospital-based case-control study of patients in northern China was to explore the association between two single-nucleotide polymorphisms (SNPs) rs401681 in TERT and rs2736100 in CLPTM1L and the risk of head and neck cancer. We collected samples and relative characteristics and then analyzed the relationship between SNPs and pharynx-larynx cancer susceptibility by logistic regression analysis. The results suggested that the male patients carrying CT and CT+CC genotype model of rs401681 was associated with reduced risk of pharynx-larynx cancer compared with the CC genotype (adjusted odds ratios were 0.701 and 0.704, and 95% confidence intervals were 0.495-0.992 and 0.506-0.980; p-values were 0.045 and 0.038, respectively). In addition, we found that subjects with allele-C showed a relatively low risk of pharyngeal cancer when smoking exposure history was obtained. But the limitation is that in the future we need to further investigate about the exact functional effect of these two variant genes and a larger scale sample. Overall, in this research, our results show that the TERT-CLPTM1L gene could be a meaningful biomarker for pharynx-larynx cancer susceptibility.

Prediction of Alzheimer's Disease-Associated Genes by Integration of GWAS Summary Data and Expression Data

Alzheimer's disease (AD) is the most common cause of dementia. It is the fifth leading cause of death among elderly people. With high genetic heritability (79%), finding the disease's causal genes is a crucial step in finding a treatment for AD. Following the International Genomics of Alzheimer's Project (IGAP), many disease-associated genes have been identified; however, we do not have enough knowledge about how those disease-associated genes affect gene expression and disease-related pathways. We integrated GWAS summary data from IGAP and five different expression-level data by using the transcriptome-wide association study method and identified 15 disease-causal genes under strict multiple testing (α < 0.05), and four genes are newly identified. We identified an additional 29 potential disease-causal genes under a false discovery rate (α < 0.05), and 21 of them are newly identified. Many genes we identified are also associated with an autoimmune disorder.