C-kit Mutations in Endometrial Cancer: Correlation with Tumor Histologic Type

Molecular Evaluation of Low-grade Low-stage Endometrial Cancer With and Without Recurrence

Low-grade, low-stage endometrioid carcinomas (LGLS EC) demonstrate 5-yr survival rates up to 95%. However, a small subset of these tumors recur, and little is known about prognostic markers or established mutation profiles associated with recurrence. The goal of the current study was to identify the molecular profiles of the primary carcinomas and the genomic differences between primary tumors and subsequent recurrences. Four cases of LGLS EC with recurrence and 8 cases without recurrence were evaluated via whole-exome sequencing. Three of the 4 recurrent tumors were evaluated via Oncomine Comprehensive Assay. The resulting molecular profiles of the primary and recurrent tumors were compared. Two of the 3 recurrent cases showed additional mutations in the recurrence. One recurrent tumor included an additional TP53 mutation and the other recurrent tumor showed POLE and DDR2 kinase gene mutation. The POLE mutation occurred outside the exonuclease domain. PIK3CA mutations were detected in 4 of 4 primary LGLS EC with recurrence and in 3 of 8 disease-free cases. LGLS EC with recurrence showed higher MSIsensor scores compared with LGLS without recurrence. The level of copy number gains in LGLS EC with recurrence was larger than LGLS EC without recurrence. This pilot study showed 1 of 3 recurrent cases gained a mutation associated with genetic instability (TP53) and 1 of them also acquired a mutation in the DDR2 kinase, a potential therapeutic target. We also noted a higher level of copy number gains, MSIsensor scores and PIK3CA mutations in the primary tumors that later recurred.

Distinct expression profile of lncRNA in endometrial carcinoma

Endometrial carcinoma (EC) is the most common malignancy in women. Dispite its prevalence, the prognosis of endometrial carcinoma still relies on conventional histological type, grade and invasion information. Its morbidity is still increasing and the outcome is very poor. To the best of our knowledge, hormonal imbalance and/or molecular genetic alterations are the main cause of EC. However, the alterations of lncRNAs which accounts for approximately 4/5 of human transcripts are still poorly understood. In the present study, using the RiboArray™ Custom Array, we studied the expression profiles of lncRNA in EC as compared to normal endometrium (NE) to find potential core lncRNAs for the diagnosis of EC. We found the potential core lncRNA by GO, KEGG, lncRNA and mRNA co-expression network. The potential functional lncRNAs were further detected by qPCR to validate the microarray results. A total of 172 lncRNAs and 188 mRNAs were found to be differentially expressed between type Ⅰ EC and the NE samples (fold change >1.5). qPCR validation showed good consistency with the microarray data. GO, pathway analysis, the lncRNA and mRNA co-expression network as well as the TCGA data revealed that 6 lncRNAs (KIAA0087, RP11-501O2, FAM212B-AS1, LOC102723552, RP11-140I24 and RP11-600K151) may be the core regulators of endometrial carcinogenesis. The potential core lncRNAs revealed by the mRNA and lncRNA co-expression network might be helpful to explore potential early diagnostic and therapeutic targets for EC.