Osteosarcoma is the most common primary bone tumor in children and adolescents. Although combined therapy including surgery and multi-agent chemotherapy have resulted in great improvements in the overall survival of patients, chemoresistance remains an obstacle for the treatment of osteosarcoma. Molecular targets or effective agents that are actively involved in cell death including apoptosis, ...

Tumor-infiltrating myeloid-derived suppressor cells (MDSC) are a heterogeneous and immunosuppressive cell subset that blocks the proliferation and the activity of both T and natural killer (NK) cells and promotes tumor vasculogenesis and progression. Recent evidences demonstrate that the recruitment of MDSCs in tumors also blocks senescence induced by chemotherapy promoting chemoresistance. Hen...

Mucoepidermoid carcinoma (MEC) is the most common malignancy of salivary glands. The response of MEC to chemotherapy is unpredictable, and recent advances in cancer biology suggest the involvement of cancer stem cells (CSCs) in tumor progression and chemoresistance and radioresistance phenotype. We found that histone acetyltransferase inhibitors (HDACi) were capable of disrupting CSCs in MEC. F...

Tumor-infiltrating myeloid-derived suppressor cells (MDSC) are a heterogeneous and immunosuppressive cell subset that blocks the proliferation and the activity of both T and natural killer (NK) cells and promotes tumor vasculogenesis and progression. Recent evidences demonstrate that the recruitment of MDSCs in tumors also blocks senescence induced by chemotherapy promoting chemoresistance. Hen...

Inducible nitric oxide synthase (iNOS or NOS2) is expressed in malignant glioma. Previously we noted that C6 glioma cells overexpressing NOS2 displayed chemoresistance against 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and other chloroethylnitrosourea derivatives with carbamoylating action. Herein we report experimental evidence supporting the contention that this NOS2 effect is mediated, at l...

This review focuses on the application of drug-loaded nanoparticles (NPs), also called therapeutic NPs, to combat cancer chemoresistance. Many cancer patients have encouraging response to first line chemotherapies but end up with cancer progression or cancer recurrence that requires further treatment. Response to subsequent chemotherapies with various agents usually drops significantly due to f...

Cellular detoxification, such as that mediated by the glutathione (GSH) system, is involved in the metabolism of various cytotoxic agents. Little is known, however, about the clinical relevance of cellular detoxification in chemoresistance. To elucidate the relevance of the GSH system to the resistance to chemotherapy observed in patients with ovarian cancer, we assayed the expression of mRNA e...

Pancreatic cancer ranks among the tumors most resistant to chemotherapy. Such chemoresistance of tumors can be mediated by various cellular mechanisms including dysregulated apoptosis or ineffective drug concentration at the intracellular target sites. In this review, we highlight recent advances in experimental chemotherapy underlining the role of cellular transporters in drug resistance. Such...

Ubiquitin-conjugating enzyme 9 (Ubc9), the sole conjugating enzyme for sumoylation, regulates protein function and plays an important role in tumorigenesis. Whether Ubc9 is involved in the chemoresistance of breast cancer remains unknown. In this study, we aimed to evaluate the contribution of Ubc9 in the chemoresistance of breast cancer. Immunohistochemistry (IHC) was used to examine the expre...

Macrophages are essential components of the inflammatory microenvironment of tumors. Conventional treatment modalities (chemotherapy and radiotherapy), targeted drugs, antiangiogenic agents, and immunotherapy, including checkpoint blockade, all profoundly influence or depend on the function of tumor-associated macrophages (TAMs). Chemotherapy and radiotherapy can have dual influences on TAMs in...