Single-cell transcriptomics dissects the transcriptome alterations of hematopoietic stem cells in myelodysplastic neoplasms.

BACKGROUND: Myelodysplastic neoplasms (MDS) are myeloid neoplasms characterized by disordered differentiation of hematopoietic stem cells and a predisposition to acute myeloid leukemia (AML). The underline pathogenesis remains unclear. METHODS: In this study, the trajectory of differentiation and mechanisms of leukemic transformation were explored through bioinformatics analysis of single-cell RNA-Seq data from hematopoietic stem and progenitor cells (HSPCs) in MDS patients. RESULTS: Among the HSPC clusters, the proportion of common myeloid progenitor (CMP) was the main cell cluster in the patients with excess blasts (EB)/ secondary AML. Cell cycle analysis indicated the CMP of MDS patients were in an active proliferative state. The genes involved in the cell proliferation, such as MAML3 and PLCB1, were up-regulated in MDS CMP. Further validation analysis indicated that the expression levels of MAML3 and PLCB1 in patients with MDS-EB were significantly higher than those without EB. Patients with high expression of PLCB1 had a higher risk of transformation to AML. PLCB1 inhibitor can suppress proliferation, induce cell cycle arrest, and activate apoptosis of leukemic cells in vitro. CONCLUSION: This study revealed the transcriptomic change of HSPCs in MDS patients along the pseudotime and indicated that PLCB1 plays a key role in the transformation of MDS into leukemia.

Erratum: Clinical outcomes in primary scalp angiosarcoma.

[This corrects the article DOI: 10.3892/ol.2019.10886.].

Clinical outcomes in primary scalp angiosarcoma.

Scalp angiosarcoma is a rare, extremely aggressive cutaneous malignancy with poor patient prognosis. The present study reviewed the cases of 42 patients who presented scalp angiosarcoma and were treated at the Zhongshan Hospital of Fudan University between January 2002 and December 2013. The clinical characteristics, demographics, treatment regimens and outcomes of patients were analyzed, and the overall survival (OS) and recurrence-free survival (RFS) rates were calculated. A total of 42 patients were examined in this study. Surgery was the most common therapeutic measure, and was performed in 39 patients, alone (12 patients), in combination with chemotherapy (14 patients), radiotherapy (6 patients) or 3-modality-therapy (7 patients). The median follow-up time of patients was 28.5 months. The 5-year OS rate was 19%, and the 5-year RFS rate was 10%. Taken together, the results of the present study suggested that patients whose tumor presented a nodular localized lesion had a significantly improved OS rate (P=0.0078). Patients aged ≥70 years were associated with a lower 5-year OS (P=0.0071) and RFS rates (P=0.0095) vs. patients aged <70 years. Different treatments were not identified to be significantly associated with an improved OS or RFS. The present results also indicated that if the tumor presented nodular localized lesions, the patients exhibited a better prognosis than those with a diffuse lesion. Although younger patients had better clinical outcomes, the likelihood of recurrence and mortality remained high for all patients.