Targeting the osteosarcoma cancer stem cell

Abstract

Osteosarcoma is the most common type of solid bone cancer and the second leading cause of cancer-related death in pediatric patients. Many patients are not cured by the current osteosarcoma therapy consisting of combination chemotherapy along with surgery and thus new treatments are urgently needed. In the last decade, cancer stem cells have been identified in many tumors such as leukemia, brain, breast, head and neck, colon, skin, pancreatic, and prostate cancers and these cells are proposed to play major roles in drug resistance, tumor recurrence, and metastasis. Recent studies have shown evidence that osteosarcoma also possesses cancer stem cells. This review summarizes the current knowledge about the osteosarcoma cancer stem cell including the methods used for its isolation, its properties, and its potential as a new target for osteosarcoma treatment.

Figure 1

The impact of the osteosarcoma cancer stem cell model on future treatment design. (A) The response of osteosarcoma to chemotherapy alone: Chemotherapy shrinks the bulk of the tumor. However, chemoresistant CSCs may survive this therapy and then can self-renew and differentiate to reform the bulk of the tumor. CSCs therefore are responsible for osteosarcoma chemoresistance and tumor recurrence. (B) The proposed response of osteosarcoma to a combination of chemotherapy and CSC-targeted therapy: Combinational treatment will not only kill the majority of tumor cells but also the CSCs. The remaining non-CSC tumor cells will eventually exhaust their growth ability, resulting in complete eradication of the tumor.