Short-Form Thymic Stromal Lymphopoietin (sfTSLP) Is the Predominant Isoform Expressed by Gynaecologic Cancers and Promotes Tumour Growth.

Thymic stromal lymphopoietin (TSLP) is an epithelial cell derived cytokine belonging to the IL-7 family and a key initiator of allergic inflammation. Two main isoforms of TSLP, classified as long- (lfTSLP) and short-form (sfTSLP), have been reported in human, but their expression patterns and role(s) in cancers are not yet clear. mRNA expression was examined by isoform-specific RT-PCR and RNA in situ hybridisation. Epigenetic regulation was investigated by chromatin immunoprecipitation-PCR and bisulfite sequencing. Tumour progression was investigated by gene overexpression, cell viability assay, cancer organoid culture and transwell invasion. Signals were investigated by proteome profiler protein array and RNA-sequencing. With the use of isoform-specific primers and probes, we uncovered that only sfTSLP was expressed in the cell lines and tumour tissues of human ovarian and endometrial cancers. We also showed the epigenetic regulation of sfTSLP: sfTSLP transcription was regulated by histone acetylation at promoters in ovarian cancer cells, whereas silencing of the sfTSLP transcripts was regulated by promoter DNA methylation in endometrial cancer cells. In vitro study showed that ectopically overexpressing sfTSLP promoted tumour growth but not invasion. Human phosphokinase array application demonstrated that the sfTSLP overexpression activated phosphorylation of multiple intracellular kinases (including GSK3α/ß, AMPKα1, p53, AKT1/2, ERK1/2 and Src) in ovarian cancer cells in a context-dependent manner. We further investigated the impact of sfTSLP overexpression on transcriptome by RNA-sequencing and found that EFNB2 and PBX1 were downregulated in ovarian and endometrial cancer cells, suggesting their role in sfTSLP-mediated tumour growth. In conclusion, sfTSLP is predominantly expressed in ovarian and endometrial cancers and promotes tumour growth.

Array-based comparative genomic hybridization analysis identified cyclin D1 as a target oncogene at 11q13.3 in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma is highly prevalent in Southern China and Southeast Asia. To unveil the molecular basis of this endemic disease, high-resolution comparative genomic hybridization arrays were used for systematic investigation of genomic abnormalities in 26 nasopharyngeal carcinoma samples. A comprehensive picture of genetic lesions associated with tumorigenesis of nasopharyngeal carcinoma was generated. Consistent chromosomal gains were frequently found on 1q, 3q, 8q, 11q, 12p, and 12q. High incidences of nonrandom losses were identified on chromosomes 3p, 9p, 11q, 14q, and 16q. In addition to previously characterized regions, we have identified several novel minimal regions of gains, including 3q27.3-28, 8q21-24, 11q13.1-13.3, and 12q13, which may harbor candidate nasopharyngeal carcinoma-associated oncogenes. In this study, gain of 11q13.1-13.3 was the most frequently detected chromosomal aberration and a 5.3-Mb amplicon was delineated at this region. Within this 11q13 amplicon, concordant amplification and overexpression of cyclin D1 (CCND1) oncogene was found in nasopharyngeal carcinoma cell lines, xenografts, and primary tumors. Knockdown of cyclin D1 by small interfering RNA in nasopharyngeal carcinoma cell lines led to significant decrease of cell proliferation. The findings suggest that cyclin D1 is a target oncogene at 11q13 in nasopharyngeal carcinoma and its activation plays a significant role in nasopharyngeal carcinoma tumorigenesis.