Fig 2: Overexpression of circ_WWC3 hampered tumor growth in vivo. Circ_WWC3 or Vector transfected MG63 cells were injected into the mice. (a) Tumor volume was monitored every week. (b) Tumor weight was measured after 4 weeks. (c–e) The levels of circ_WWC3, miR-421, and PDE7B in tumors collected from the mice treated with circ_WWC3 or vector were measured by qRT-PCR assay. (f) The protein level of PDE7B in tumors collected from the mice treated with circ_WWC3 or vector was measured by western blot assay. *P < 0.05.

Fig 3: PDE7B overexpression suppressed OS cell colony formation, proliferation, migration, and invasion and promoted apoptosis. (a–d) The mRNA and protein levels of PDE7B in OS tissues, cells, and corresponding normal tissues and cells were measured by qRT-PCR assay and western blot assay, respectively. (e–n) MG63 and SaOS-2 cells were transfected with PDE7B or pcDNA. (e and f) The mRNA and protein levels of PDE7B in MG63 and SaOS-2 cells were detected via qRT-PCR assay or western blot assay. (g) Cell colony formation, (h and i) proliferation, (j and k) migration, invasion, and (l) apoptosis in MG63 and SaOS-2 cells were assessed through colony formation assay, MTT assay, transwell assay, and flow cytometry analysis, respectively. (m and n) Western blot analysis was performed for the levels of Bcl-2, Bax, and cleaved caspase-3 in MG63 and SaOS-2 cells. *P < 0.05.

Fig 4: Inhibition of miR-421 suppressed the malignant phenotypes of OS cells by binding to PDE7B. MG63 and SaOS-2 cells were transfected with anti-miR-421, anti-miR-NC, anti-miR-421 + si-NC, or anti-miR-421 + si-PDE7B. (a and b) The mRNA and protein levels of PDE7B in MG63 and SaOS-2 cells were detected by qRT-PCR assay and western blot assay, respectively. (c–h) Cell colony formation, proliferation, migration, invasion, and apoptosis in MG63 and SaOS-2 cells were evaluated by colony formation assay, MTT assay, transwell assay, and flow cytometry analysis, respectively. (i and j) The protein levels of Bcl-2, Bax, and cleaved caspase-3 in MG63 and SaOS-2 cells were measured by western blot assay. *P < 0.05.