Apoptotic effect of pyrroloquinoline quinone on chondrosarcoma cells through activation of the mitochondrial caspase‑dependent and caspase‑independent pathways

Oncology Reports
Ronghuan WuChunyang Xing

Abstract

Chondrosarcomas are malignant tumors of the bone that exhibit resistance to chemotherapy and radiation. Pyrroloquinoline quinone (PQQ) is a bacterial redox co‑factor and antioxidant that has been found to induce apoptosis in various cancer cells. This study investigated the role of PQQ in cell apoptosis of chondrosarcoma cells and the underlying pathways involved. We confirmed that PQQ was cytotoxic to chondrosarcoma SW1353 cells by a cell cytotoxicity assay. Furthermore, flow cytometry showed that the number of apoptotic cells increased in a concentration‑dependent and time‑dependent manner following PQQ treatment, but this effect was not significant in normal cells. Co‑immunoprecipitation assays showed that the binding of Smac to X‑linked inhibitor‑of‑apoptosis protein (XIAP) was significantly increased and the binding of XIAP with caspase‑3 was significantly decreased following PQQ treatment. This was accompanied by a decrease in the levels of caspase‑1 and procaspase‑3, as demonstrated by western blot analysis. Western blotting also showed that the level of cytochrome c in the mitochondria was decreased and its level in the cytoplasm was increased. These findings indicate the role of caspase‑dependent apoptotic pathways in ...Continue Reading

Related Concepts

Related Feeds

Apoptosis

Apoptosis is a specific process that leads to programmed cell death through the activation of an evolutionary conserved intracellular pathway leading to pathognomic cellular changes distinct from cellular necrosis

Apoptosis in Cancer

Apoptosis is an important mechanism in cancer. By evading apoptosis, tumors can continue to grow without regulation and metastasize systemically. Many therapies are evaluating the use of pro-apoptotic activation to eliminate cancer growth. Here is the latest research on apoptosis in cancer.

Apoptotic Caspases

Apoptotic caspases belong to the protease enzyme family and are known to play an essential role in inflammation and programmed cell death. Here is the latest research.