DNA methylation is crucial for mammalian development, and DNA methylation is always in the dynamic status during preimplantation mouse embryos development. The effects of 5-AZA-CdR on the development of preimplantation mouse embryos were evaluated. Preimplantation mouse embryos created by in vitro fertilization were cultured continuously in 5-AZA-CdR (0.2, 1.0, or 5.0 μmol/L). Fertilized oocytes exposed to CZB containing 5-AZA-CdR at the pronuclear stage were unable to form morulae (0.2 and 1.0 μmol/L) or 4-cell embryos (5.0 μmol/L), while 2-cell stage embryos exposed to 5-AZA-CdR developed into uncompacted 8-cell (0.2 and 1.0 μmol/L) or 3/4-cell (5.0 μmol/L) stage embryos. The rate of morula formation was significantly lower in 4-cell embryos cultured in 5-AZA-CdR (1.0 or 5.0 μmol/L) than that in control embryos (P < 0.05). These data indicate that 5-AZA-CdR inhibits the development of mouse preimplantation embryos. Apoptosis, DNA methylation, and transcriptional activity were analyzed to determine the reason for these developmental defects. An aunexin V-PI assay revealed that high doses of 5-AZA-CdR led to apoptosis. Compared to the controls, DNA methylation was significantly reduced in uncompacted 8-cell embryos and morulae (p < 0.05) in a dose- dependent manner, whereas no significant change was detected in 2-or 4-cell embryos (P > 0.05). The observed changes in transcriptional activity, determined by measuring the incorporation of BrUTP, were similar to the observed alterations in DNA methylation. Therefore, the developmental defects induced by 5-AZA-CdR appear to bc mediated by alterations in DNA methylation and transcriptional activity in preimplantation mouse embryos.

Objective: To investigate the clinicopathological features, diagnosis and differential diagnosis of dedifferentiated liposarcoma (DDLPS) with inflammatory myofibroblastic tumor (IMT)-like features. Methods: Five cases of DDLPS with IMT-like features were collected from the First Affiliated Hospital of Nanjing Medical University, the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine and the First People′s Hospital of Qinzhou between 2013 and 2018. EnVision method and fluorescence in situ hybridization (FISH) were used to detect the immunophenotype of the tumor cells and the profile of MDM2 gene amplification respectively. Results: All five cases were male and the median age was 61 (range 53 to 65) years. The clinical symptoms were mainly related to the space-occupying lesions. The tumors were located in duodenal mesentery (two cases), intestinal wall (one case), retroperitoneum (one case), and spermatic cord (one case). Grossly, the tumors were not well encapsulated, ranging from 3 to 13 cm (median 6.7 cm) in diameter, with tan to gray and firm cut surface. Histologically, the dedifferentiated component closely resembled inflammatory myofibroblastic tumor (IMT), with spindle/polygonal/stellate-shaped cells arranged in storiform, sheet-like, or random pattern, with varying degrees of chronic inflammation and fibrosis. All three major patterns seen in IMT (myxoid, cellular and hypocellular fibrous) were observed, the hypocellular fibrous pattern was the most common. Well-differentiated liposarcomatous component was found in the peripheral areas of all the tumors. One case had high grade dedifferentiated component. Four cases were strongly positive for MDM2 and p16. Two cases were positive for SMA, and one case was focally positive for desmin and one for CD34. None of the cases stained for ALK-1. FISH demonstrated MDM2 gene amplification in all five cases. Clinical follow-ups were available in all five cases and the interval ranged from 3 to 66 months (median 23 months). Two patients developed recurrences and one patient had metastasis. The remaining two patients were alive with no evidence of tumor recurrence at 3 and 14 months after surgery respectively. Conclusions DDLPS with IMT-like features is a more aggressive neoplasm than its histological mimic (IMT), and should not be misdiagnosed as other intermediate or low-grade malignant tumors, such as IMT, sclerosing liposarcoma, inflammatory liposarcoma, aggressive fibromatosis, solitary fibrous tumors, low-grade myofibroblastic sarcoma, and low-grade fibrosarcoma.