Mirna control

Irradiation was performed in a linear accelerator (Varian 600, Varian, USA) at a dose rate of 3.2 Gy/min. circ_0012381 overexpression, circ_0012381 inhibitor, circRNA control, miR-340-5p overexpression, miR-340-5p inhibitor, and miRNA control lentiviruses were synthesized by Genechem (Shanghai, China) (Additional file 1: Table S1). To block exosome generation, U251 or U87 cells were incubated with 10 µM GW4869 (Sigma-Aldrich), which was initially dissolved in DMSO into a stock solution of 5 mM and diluted in culture medium, for 24 h.

MiR‐203 mimics, miR‐203 inhibitor, miRNA control, plasmid mediated circRUNX2 overexpression, circRUNX2 siRNA, and control vector were purchased from Genechem (Shanghai, PR, China). HBMSCs were planted in 6‐well plates for 24 hours prior to the transfection with 50%‐60% confluence, and then were transfected with Lipofectamine 2000 (Invitrogen, Carlsbad, CA, USA) according to the manufacturer's instructions.

Recombinant lentiviruses containing over-expression of miRNA-195, knocking down of miRNA-195 and miRNA control were purchased from GeneChem (Shanghai, China). Besides the multiple clone sites of lenti-virus expression vectors, there also was a GFP reporter driven by an independent promoter (SV40 promoter) to indicate the infection rate of virus infection timely.
To generate the stable cell line, 1×10⁴ cells were transfected with 5×10⁵ transducing units of lentiviruses. The supernatant was removed after 24h and replaced with complete culture medium. Infection efficiency was confirmed by RT-PCR 96h after infection and the cells were selected with 1μg/ml puromycin for 2 weeks.