Abstract.Cancer is caused by multiple genetic alterations within cells. Recently, large-scale sequencing has identified frequent ribonuclease type III (DICER1), CCCTC-binding factor (CTCF), ribosomal protein L22 (RPL22), DNA (cytosine-5-)-methyltransferase 3α (DNMT3A), transformation/transcription domain-associated protein (TRRAP), isocitrate dehydrogenase (IDH)1 and IDH2 hotspot mutations in diverse types of cancer. However, it remains largely unknown whether these mutations also exist in ovarian carcinomas. In the present study, a collection of 251 patients with distinct subtypes of ovarian carcinomas were recruited and sequenced for the presence of these hotspot mutations. However, no mutations in the seven genes were detected in the samples. These negative results, together with certain recent reports, indicate that the hotspot mutations in the CTCF, RPL22, DNMT3A, TRRAP, IDH1 and IDH2 genes may not be actively involved in the carcinogenesis of ovarian carcinoma. Of note, the DICER1 mutation frequency in Sertoli-Leydig cell tumor in the present study was significantly lower compared to prior observation, and therefore, it is speculated that this discrepancy may be mainly due to the small sample size analyzed in the study. In addition, among these samples, frequent polymerase (DNA directed) ε, catalytic subunit (POLE1) and ring finger protein 43 (RNF43) mutations were identified in endometrioid and mucinous ovarian carcinomas, respectively; thus DICER1, CTCF, RPL22, DNMT3A, TRRAP, IDH1 and IDH2 hotspot mutations may not play synergistic roles with POLE1 or RNF43 mutations in the carcinogenesis of endometrioid or mucinous ovarian carcinomas.
IntroductionThe current understanding of human malignancy is that it mainly arises due to the accumulation of multiple genetic alterations, transforming normal cells into malignant cells (1,2). Of these genetic alterations, a myriad of genomic mutation data derived from a high-throughput DNA sequencing technique provided a unique opportunity to profile the mutation spectra underlying human cancers and a large number of significant functional mutations in multiple genes were identified in diverse types of cancer (1,3,4). These genes can be defined as oncogenes or tumor suppressor genes and are being used as molecular markers for diagnosis, staging and prognosis of human cancers (5,6).Ovarian carcinoma constitutes a heterogeneous group of malignancies with significantly different clinical expression, pathological characteristics and genetic etiology (7,8). However, the majority of ovarian carcinomas shared certain common genetic alterations, such as frequent tumor protein p53 (TP53) and PIK3CA, catalytic subunit α mutations (9,10), and patients also exhibited subtype-specific mutations (11-13), which are possibly essential for the differential clinical expression and molecular-targeted therapy in ovarian carcinomas (14,15). These observations emphasized the requirement to identify novel subtype-specific molecular genetic aberrations in ovarian carcinomas.Recently, large-scal...