SP1-Induced Upregulation of LncRNA AFAP1-AS1 Promotes Tumor Progression in Triple-Negative Breast Cancer by Regulating mTOR Pathway.

The long non-coding RNA (lncRNA) actin fiber-associated protein-1 antisense RNA 1 (AFAP1-AS1) exerted oncogenic activity in triple-negative breast cancer (TNBC). We designed this study and conducted it to investigate the upstream regulation mechanism of AFAP1-AS1 in TNBC tumorigenesis. In this work, we proved the localization of AFAP1-AS1 in the cytoplasm. We elucidated the mechanism by which the transcription factor specificity protein 1 (SP1) modulated AFAP1-AS1 in TNBC progression, which has yet to be thoroughly studied. Dual luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay revealed a strong affinity of SP1 toward the promoter regions P3 of AFAP1-AS1, proving the gene expression regulation of AFAP1-AS1 via SP1 in TNBC. Additionally, SP1 could facilitate the tumorigenesis of TNBC cells in vitro and in vivo by regulating the AFAP1-AS1 expression. Furthermore, silenced AFAP1-AS1 suppressed the expression of genes in the mTOR pathway, such as eukaryotic translation initiation factor 4B (EIF4B), mitogen-activated protein kinase-associated protein 1 (MAPKAP1), SEH1-like nucleoporin (SEH1L), serum/glucocorticoid regulated kinase 1 (SGK1), and its target NEDD4-like E3 ubiquitin protein ligase (NEDD4L), and promoted the gene expression of s-phase kinase-associated protein 2 (SKP2). Overall, this study emphasized the oncogenic role of SP1 and AFAP1-AS1 in TNBC and illustrated the AFAP1-AS1 upstream interaction with SP1 and the downstream modulatory of mTOR signaling, thus offering insights into the tumorigenesis mechanism in TNBC.

A case report of primary angiosarcoma of the breast.

Background: Breast Angiosarcoma can be divided into primary breast angiosarcoma (PBA) and second breast angiosarcoma (SBA). PBA is rare malignant breast cancer with poor outcomes. PBA usually occurs in women between 30-40 years old. PBA does not have a specific clinical manifestation. Clinically, PBA presents with a rapidly enlarging breast mass and skin involvement with skin color changes. Ultrasonography of PBA can be hypoechoic or hyperechoic, or mixed disordered areas. Microscopically, PBA can be classified into three grades according to the degree of differentiation, and the grade is related to the prognosis. And PBA can also express vascular endothelial markers. The main treatment for PBA is surgery, especially mastectomy. There are other treatments, such as chemotherapy and radiotherapy, but their effectiveness needs further confirmation. Targeted drugs may be helpful. Case Description: A 32-year-old woman with main clinical presentation of a rapidly growing mass located in the upper inner quadrant of the right breast with skin involvement. PBA was diagnosed with first extended local resection, and then the patient underwent a second right mastectomy. The patient is now undergoing chemotherapy. Conclusions: Since this is a rare form of breast cancer, we report this case to raise the attention of breast surgeons to avoid misdiagnoses.