Disulfiram reduces metastatic osteosarcoma tumor burden in an immunocompetent Balb/c or-thotopic mouse model

Abstract

IntroductionThe overall survival rate of patients with osteosarcoma (OS) and pulmonary metastases has remained stagnant at 15–30% for several decades. Disulfiram (DSF) is an FDA-approved aldehyde dehydrogenase inhibitor that reduces the metastatic phenotype of OS cells in vitro. Here we evaluate its in vivo efficacy, as compared to doxorubicin chemotherapy, in a previously-validated orthotopic model of metastatic OS.ResultsAll treatment groups displayed a significantly reduced quantitative OS metastatic burden compared with controls. The metastatic burden of Lo DSF-treated animals was equivalent to the DXR group. Ninety-five percent of control animals displayed evidence of metastatic disease, which was significantly greater than all treatment groups.DiscussionDisulfiram treatment resulted in a reduced burden of OS metastatic disease compared with controls. This was statistically-equivalent to doxorubicin. No additive effect was observed between these two therapies.Materials and MethodsOne-hundred twenty immunocompetent Balb/c mice received proximal tibia paraphyseal injections of 5 × 105 K7M2 murine OS cells. Therapy began three weeks after injection: saline (control), low-dose disulfiram (Lo DSF), high-dose disulfiram (Hi DSF), doxorubicin (DXR), Lo DSF + DXR, and Hi DSF + DXR. Transfemoral amputations were performed at 4 weeks. Quantitative metastatic tumor burden was measured using near-infrared indocyanine green (ICG) angiography.

Tumor Resection Guided by Intraoperative Indocyanine Green Dye Fluorescence Angiography Results in Negative Surgical Margins and Decreased Local Recurrence in an Orthotopic Mouse Model of Osteosarcoma

“…After approval by the University of Pittsburgh Institutional Animal Care and Use Committee (IACUC Protocol# 16119548), fifty 6-week-old immunocompetent Balb/c female mice received left proximal tibia paraphyseal injections of 5 × 10 5 K7M2 murine OS cells, as has been previously described 15,18. Mice were then prospectively separated into two groups ( n = 25 each): (1) ICG-assisted surgical resection; and (2) no ICG-assisted resection.…”

“…All ICG measurements were performed using the SPY-Elite System (Stryker Corporation, Kalamazoo, MI, USA) as previously described. The timing and dosage of ICG administration was also based on our previous work 15,18. Surgical resections in group 1 were performed under the direct guidance of ICG–infrared imaging until there was no longer any fluorescent signal in the remaining hind limb (Fig.…”

CSCs: regenerating optimism for osteosarcoma treatment

“…Despite decades of ingenuity and investigation, the prognosis for a patient with metastatic osteosarcoma remains similar to that described by Meyers et al in 1993 [ 2 ], and the prognosis still depends in large part on the ability to surgically eradicate all evidence of disease. In this context, the study by Crasto et al [ 3 ] is a reason for renewed enthusiasm. Cancer stem cells (CSCs) represent a subpopulation of tumor cells that are thought to promote tumorigenesis.…”

“…Elevated aldehyde dehydrogenase (ALDH) activity is associated with CSCs in both solid tumors and hematologic malignancies and has been similarly implicated in chemoresistance and tumorigenesis. Crasto et al [ 3 ] used disulfiram as an ALDH inhibitor to target the CSC subpopulation in a murine osteosarcoma model. The authors showed a reduction in metastatic tumor burden after treatment with disulfiram, which was comparable to that achieved with doxorubicin chemotherapy.…”

“…Moreover, the findings appear to have implications for other solid tumors beyond this rare disease. Potentially overlooked in the analysis by Crasto et al [ 3 ], however, is an equally intriguing and exciting advance included in the analytical methods—the use of indocyanine green near-infrared fluorescence in the evaluation of osteosarcoma tumor burden. As noted by Crasto et al, the systemic treatments’ benefits of disulfiram and doxorubicin were largely in preventing the development of metastases, which is consistent with decades of human clinical results highlighting the role of complete surgical excision of the primary tumor in the treatment of osteosarcoma.…”