Project description:Here, we performed single cell RNA sequencing (scRNA-seq) analysis for 27, 810 cells from 2 donors with primary salivary gland pleomorphic adenoma
Project description:BACKGROUND: potential epigenetic biomarkers for malignant transformation to carcinoma ex pleomorphic adenoma (Ca ex PSA) have been sought previously with and without specific comparison with the benign variant, pleomorphic salivary adenoma (PSA). Previous analysis has been limited by a non-quantitative approach. We sought to demonstrate quantitative promoter methylation across a panel of tumour suppressor genes (TSGs) in both Ca ex PSA and PSA. METHODS: quantitative methylation-specific real-time polymerase chain reaction (qMSP) analysis of p16(INK4A), CYGB, RASSF1, RAR?, human telomerase reverse transcriptase (hTERT), Wilms' tumour 1 (WT1) and TMEFF2 gene promoters was undertaken on bisulphite-converted DNA, previously extracted from archival fixed tissue specimens of 31 Ca ex PSA and an unrelated cohort of 28 PSA. All target regions examined had formerly been shown to be hypermethylated in salivary and/or mucosal head and neck malignancies. RESULTS: the qMSP demonstrated abnormal methylation of at least one target in 20 out of 31 (64.5%) Ca ex PSA and 2 out of 28 (7.1%) PSA samples (P<0.001). RASSF1 was the single gene promoter for which methylation is shown to be a statistically significant predictor of malignant disease (P<0.001) with a sensitivity of 51.6% and a specificity of 92.9%. RAR?, TMEFF2 and CYGB displayed no apparent methylation, while a combinatory epigenotype based on p16, hTERT, RASSF1 and WT1 was associated with a significantly higher chance of detecting malignancy in any positive sample (odds ratio: 24, 95% CI: 4.7-125, P<0.001). CONCLUSIONS: we demonstrate the successful application of qMSP to a large series of historical Ca ex PSA samples and report on a panel of TSGs with significant differences in their methylation profiles between benign and malignant variants of pleomorphic salivary adenoma. qMSP analysis could be developed as a useful clinical tool to differentiate between Ca ex PSA and its benign precursor.
Project description:The global gene expression profiles of 162 myxofibrosarcomas and undifferentiated pleomorphic sarcomas were studied by RNA-sequencing. The profiles were compared with clinical and genomic features. 21 soft tissue tumors of other histotypes were used as out-group.
Project description:N6-methyladenosine (m6A) is one of the most popular RNA modifications, which is widely found in messenger RNAs (mRNAs) .In our study,we provide m6A profiles of human invasive malignant pleomorphic adenoma, which open an avenue for in-depth knowledge and understanding of m6A topology in invasive malignant pleomorphic adenoma.
Project description:Invasive malignant pleomorphic adenoma (IMPA) results from the malignant transformation of pleomorphic adenoma (PA). The former is a high-grade malignant tumor, whereas the latter is a benign opposite. Study on the molecular mechanism in the progression of PA to IMPA will be of benefit to elucidate the reasons for different biological behaviors among these salivary gland tumors with the same origin. But there is no valuable and non-invasive biomarker to screen IMPA currently. Studies showed many salivary molecules can detect several systemic diseases. We aimed to investigate whether salivary mRNAs (mRNA) can act as a biomarker to detect IMPA.
Project description:20 tumor samples run in duplicates, consisting of pleomorphic sarcomas; classfied as leiomyosarcoma or high-grade undifferentiated pleomorphic sarcoma.
Project description:Salivary duct carcinoma (SDC) is morphologically similar to breast cancer, with HER2-overexpression reported. With regard to the pattern of disease onset, SDC can arise from de novo or carcinoma ex-pleomorphic adenoma (Ca-ex-PA). Recently, multiple molecular profiles of SDC as well as breast cancer have been reported, with significant differences in HER2 expression between Ca-ex-PA and de novo. We assessed the differences in gene expression between onset classifications. We conducted immunohistochemical analysis and HER2-DISH for 23 patients and classified SDCs into three subtypes as follows: "HER2-positive" (HER2+/any AR), "Luminal-AR" (HER2-/AR+), and "Basal-like" (HER2-/AR-). We assessed the expression levels of 84 functional genes for 19 patients by using a qRT-PCR array. Ten cases were classified as HER2-positive, seven cases as Luminal-AR, and six cases as Basal-like. The gene expression pattern was generally consistent with the corresponding immunostaining classification. The expression levels of VEGFA, ERBB2(HER2), IGF1R, RB1, and XBP1 were higher, while those of SLIT2 and PTEN were lower in Ca-ex-PA than in de novo. The functions of those genes were concentrated in angiogenesis and AKT/PI3K signaling pathway (Fisher's test: p-value = 0.025 and 0.004, respectively). Multiple machine learning methods, OPLS-DA, LASSO, and RandomForest, also show that VEGFA can be a candidate for the characteristic differences between Ca-ex-PA and de novo. In conclusion, the AKT/PI3K signaling pathway leading to angiogenesis was hyper-activated in all SDCs, particularly in those classified into the Ca-ex-PAs. VEGFA was over-expressed significantly in the Ca-ex-PA, which can be a crucial factor in the malignant conversion to SDC.
Project description:Supposed risk of malignant transformation of salivary gland pleomorphic adenoma (SGPA) is an important reason for aggressive retreatment in recurrent pleomorphic adenoma (RPA). However, although the diagnostic category 'carcinoma ex-pleomorphic adenoma' suggests that malignant transformation of a pleomorphic adenoma is a regular event, this has to date not been shown to occur in sequential lesions of one patient. Here, we show the molecular events in transformation to malignancy of a pleomorphic adenoma of the parotid gland. Detailed molecular analysis revealed an LIFR/PLAG1 translocation characteristic for pleomorphic adenoma and, next to this, a PIK3R1 frameshift mutation and several allelic imbalances. In subsequent malignant recurrences, the same LIFR/PLAG1 translocation, PIK3R1 frameshift mutation, and allelic imbalances were present in addition to TP53 mutations. Thus, this case not only shows malignant transformation of SGPA, but also demonstrates that molecular analysis can be of help in recognising malignancy in the rare instance of RPA.