Evaluation of the effects of two different bone resorption inhibitors on osteoclast numbers and activity: An animal study

The effect of low-level laser radiation and doxycycline on the levels of osteoprotegerin and receptor activator of nuclear factor kappa-B ligand

The present in vitro study was conducted to investigate the effect of low-level laser (LLL) radiation and doxycycline on the levels of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) derived from MG-63 osteosarcoma cell line. MG-63 cells were divided into four groups. In the first group, 2 mg/mL of doxycycline was injected into the cell culture medium. Diode laser (810 nm, 100 mw, 75 s) was radiated to the culture medium of the second group. The third group received both doxycycline and laser radiation. In the fourth group (control), the culture medium was replaced daily, similar to the above three groups. Mentioned interventions were performed once a day for 4 consecutive days. Then, on the sixth day, the levels of OPG and RANKL mediators were measured using real-time polymerase chain reaction by isolating the cells from the samples. OPG expression had the highest to lowest levels in the laser + doxycycline, doxycycline, laser, and control groups, respectively. The level of OPG was significantly different between all the study groups (p < 0.05) except in the doxycycline + laser and doxycycline groups (p = 0.061). The highest to lowest levels of RANKL was observed in the doxycycline, laser + doxycycline, control, and laser groups, respectively. The RANKL expression was not significantly different between all the study groups (p > 0.05). The results of this study revealed that LLL and doxycycline reduced the RANKL/OPG ratio derived from the MG-63 osteosarcoma cell line, which may result in the diminished activity of osteoclasts and osteoclastogenesis.

Image-Guided Percutaneous Management of Skull and Spine Giant Cell Tumors: Case Report of 2 Challenging Cases Successfully Treated with Doxycycline Sclerotherapy

Background

A giant cell tumor (GCT) of bone is a benign, locally aggressive tumor that is often challenging to treat. When complete resection is not possible, curettage with or without adjuvants is the most common treatment. The high frequency of local recurrence and risk of injury to adjacent structures can limit this surgical approach, especially with skull and spine lesions.

Case Description

We report 2 cases of axial skeleton GCTs, 1 in the skull of a 58-year-old woman in whom operative management failed, who experienced local recurrence, and 1 in the cervical spine of an 8-year-old girl that grew extracompartmentally to surround her brachial plexus. Both patients were referred to us because of the surgically challenging nature of their tumors. After completion of the same percutaneous doxycycline sclerotherapy protocol previously described for aneurysmal bone cysts (ABCs), both patients were considered cured and were able to return to normal activities without loss of pretreatment function. After 4 and 10 years of follow-up, respectively, there has been no tumor recurrence in either patient.

Conclusions

We successfully treated 2 patients with very challenging axial skeleton GCTs using a percutaneous doxycycline sclerotherapy protocol previously shown to have success with ABCs. We believe that this minimally invasive procedure should be considered a potential alternative treatment for GCTs, especially axial skeleton lesions, which may not be easily approached with standard surgical techniques.

抗酒石酸酸性磷酸酶在恶性肿瘤中的研究进展

抗酒石酸酸性磷酸酶(type 5 acid phosphatase/tartrate-resistant acid phosphatase, ACP5/TRACP/TRAP)是酸性磷酸酶家族中的金属蛋白酶, 是骨吸收和破骨细胞活性的良好标志物. 近来发现ACP5在多种肿瘤中的表达比配对正常组织中的表达显著上调, 该现象提示, ACP5可能肿瘤的发生发展中起到一定的作用.