Background Breast cancer (BC) is a common cancer in women worldwide. Emerging evidence has indicated that circular RNA hsa‐circ_0007255 (circ_0007255) is a prognostic mediator in BC progression. However, the functional role of circ_0007255 needs to be determined. Methods The expression of circ_0007255, microRNA (miR)‐335‐5p, and SIX Homeobox 2 (SIX2) was evaluated using quantitative real‐time polymerase chain reaction (qRT‐PCR) or western blot assay. Actinomycin D and RNase R treatment was performed to analyze the stability of circ_0007255. Additionally, Seahorse extracellular flux, colony formation and transwell analyses were carried out to detect oxygen consumption ratio (OCR), colony formation and cell mobility, respectively. The interaction between miR‐335‐5p and circ_0007255 or SIX2 was confirmed via dual‐luciferase reporter assay. A xenograft tumor model was established to explore the role of circ_0007255 in vivo. Results Circ_0007255 and SIX2 were overexpressed, but miR‐335‐5p was diminished in BC tissues and cells. Circ_0007255 absence inhibited oxygen consumption, colony formation, cell migration and invasion, and these effects were particularly abrogated via miR‐335‐5p upregulation in BC cells. Moreover, SIX2 deficiency eliminated the promotion effects of miR‐335‐5p inhibitor on oxygen consumption, colony formation, and cell mobility in BC cells. Importantly, circ_0007255 inhibited tumor growth in vivo. Mechanically, circ_0007255 was a sponge of miR‐335‐5p to regulate SIX2 expression in BC progression. Conclusion Circ_0007255 functioned as a novel oncogene in the progression of BC by regulating miR‐335‐5p/SIX2 axis, and might be a promising biomarker for BC treatment. Key points Significant findings of the study: Levels of circ_0007255 and SIX2 were upregulated, but miR‐335‐5p was diminished in BC tissues and cells. Circ_0007255 was an oncogene in BC development and exerted its function via miR‐335‐5p/SIX2 axis in BC. Tumor growth was reduced by circ_0007255 absence. What this study adds: Circ_0007255 functioned as a novel oncogene in the progression of BC by regulating miR‐335‐5p/SIX2 axis, and might be a promising biomarker for BC treatment.

Brain metastasis frequently occurs in cancer patients and is associated with a poor prognosis. We previously reported that S100B was highly expressed in PC14/B, a specific brain metastatic lung adenocarcinoma cell line, which suggests that it is associated with brain metastasis of lung cancer. However, the role of S100B in brain metastasis remains to be elucidated. In this study, using PC14/B cell line, we found that siRNA mediated depletion of S100B in PC14/B cells led to notable differences in cell proliferation, apoptosis, cell cycle progression, colony formation ability, cell migratory and invasive activity compared with the mock-transfected cells. Therefore, our data suggest that S100B promotes the brain metastasis of lung adenocarcinoma by promoting cell proliferation, preventing apoptosis and increasing cell migration and invasion.

BackgroundWe describe a special, interesting phenomenon found in the anterior horn of the lateral meniscus (AHLM): most tear patterns in the AHLM are distinctive, with loose fibers in injured region and circumferential fiber bundles were separated. We name it as macerated tear. The goal of this study was to bring forward a new type of meniscal tear in the AHLM and investigate its clinical value.Materials and MethodsAHLM tears underwent arthroscopic surgery from January 2012 to December 2014 were included. Data regarding the integrity of AHLM were prospectively recorded in a data registry. Tear morphology and treatment received were subsequently extracted by 2 independent reviewers from operative notes and arthroscopic surgical photos.ResultsA total of 60 AHLM tears in 60 patients (mean age 27.1 years) were grouped into horizontal tears (n = 15, 25%), vertical tears (n = 14, 23%), complex tears (n = 6, 10%), and macerated tears (n = 25, 42%). There were 6 patients with AHLM cysts in macerated tear group and one patient in vertical tear group. 60 patients were performed arthroscopic meniscus repairs and were followed-up with averaged 18.7 months. Each group had significant postoperative improvement in Lysholm and IKDC scores (p < 0.05). However, the macerated tear group showed least functional recovery of Lysholm and IKDC scores compared to other groups (p < 0.05). In addition, there were no differences in postoperative range of motion, return to work, or return to sport/other baseline activities between the four groups (p > 0.05).ConclusionsThis study demonstrated that the macerated tear is common in the tear pattern of AHLM. However, feasibility of the treatment of this type of meniscal tear, especially the meniscus repairs still requires further study.