The exosomal transfer of human bone marrow mesenchymal stem cell-derived miR-1913 inhibits osteosarcoma progression by targeting NRSN2.

OBJECTIVE: Osteosarcoma is a malignant bone tumor consisting of mesenchymal cells. This study aimed to investigate the inhibitory effects of human bone marrow mesenchymal stem cell (hBMSC)-derived miR-1913 on osteosarcoma. METHODS: Cell viability was determined using CCK8 and colony formation assays. The cell migration and invasion abilities were assessed using wound healing and transwell assays. RT-qPCR and western blot were used to measure the miR-1913, Neurensin-2 (NRSN2), N-cadherin, and E-cadherin expression levels. Dual luciferase reporter assays were conducted to identify the target relationship between miR-1913 and NRSN2. The exosomes were extracted and identified using TEM and NTA assays. RESULTS: In the osteosarcoma tumor tissues and cell lines, the NRSN2 expressions were up-regulated, which correlated with a poor osteosarcoma prognosis. MiR-1913 inhibited the cell viability, proliferation, migration, and invasion by negatively targeting NRSN2. Furthermore, the hBMSC-derived exosomes delivered miR-1913 to inhibit the NRSN2 expression in the osteosarcoma cells. CONCLUSION: The inhibitory role of hBMSC-derived miR-1913 on osteosarcoma progression was achieved by targeting NRSN2, indicating the potential therapeutic value of hBMSC-derived miR-1913.

[Reconstruction of partial defects at the end of the fingers].

OBJECTIVE: To study the reconstruction of partial defects at the end of the thumbs and other fingers with microsurgical free toe flaps. METHODS: 21 partial defects (19 cases) at the end of thumbs and other fingers were reconstructed with microsurgical free toe flaps taking from the corresponding toe part. RESULTS: All the free flaps survived. The patients were followed up for 3 - 6 months. The aesthetic and functional results were both satisfactory. The two-point-discrimination distance was 4 - 6 mm. CONCLUSIONS: The microsurgical free toe flaps have good therapeutic effect for the reconstruction of partial defects at the end of the fingers.

Aesthetic reconstruction of thumb or finger partial defect with trimmed toe-flap transfer.

A new concept of esthetic reconstruction for partial loss of distal finger segment was introduced. In a series of 77 patients, 80 thumb or finger partial defects of lateral, dorsal, or volar half, or composite tissue defect of the finger body were reconstructed with lateral skin-nail flap, dorsal skin-nail flap, pulp flap, or composite tissue transplant taken from corresponding part of the toes. The blood circulations were reestablished by anastomosing digit arteries of the toe transplants and fingers. Seventy-eight fingers in 75 patients of this series were successfully reconstructed. The overall survival rate was 97.5%. Follow-up examinations made half to 12 years postoperatively showed normal length, outward appearance, and function of the reconstructed digits. Their nails are preserved or reconstructed. The pulps are full. Sweating is present. 2-PD was 4-6 mm. Esthetic reconstruction can achieve the goal of mending any part of tissue loss precisely with good result.

[Decorative repair and reconstruction of subtotal thumb and finger defect with trimmed toe flap transfer].

OBJECTIVE: In partial loss of distal finger segment, a corresponding part of the toe tissue compound is harvested and transplanted for repair or reconstruction. This new procedure gives forth a new concept and is called decorative repair or reconstruction. METHODS: In a series of 77 patients with 88 thumb and/or finger subtotal defects in forms of lateral half, dorsal half or volar half composite tissue defects were reconstructed with lateral nail-skin flap, dorsal skin-nail flap or pulp flap taken from corresponding part of the toes. The blood circulations were re-established by anastomosing digital arteries of the toe transplants and fingers. RESULTS: In this series 75 patients with 78 fingers reconstructed are successful. The overall survival rate is 97.5%. Follow-up examinations made half to 12 years postoperatively showed the fingers are having a normal length, outward appearance and function. There are nails preserved. The pulps are full. Sweating function are present. Two-point-discrimination tests are between 4-6 mm. CONCLUSION: By decorative reconstruction of subtotal dorsal, lateral, or volar halves defect of thumb and/or fingers by transplanting corresponding part of soft tissue taken from the toe has the merit of repair of any parts of tissue loss precisely what is needed. This procedure is better than any traditional toe-to-hand transfer and realizing the exact meaning of decorative reconstruction.