Role of ATP-binding cassette transporters in cancer initiation and progression.

ATP Binding Cassette (ABC) transporters, widely studied in cancer for their role in drug resistance, have been more recently also considered for their contribution to cancer cell biology. To date, many data provide evidences for their potential role in all the phases of cancer development from cancer susceptibility, tumor initiation, tumor progression and metastasis. Although many evidences are based on correlative analyses, data describing a direct or indirect role of ABC transporters in cancer biology are increasing. Overall, current available information suggests a relevant molecular effector role of some ABC transporters in cancer invasion and metastasis as reported in experimental tumor models. From a therapeutic point of view, due to the physiological relevant roles that ABC transporters play in the organism, the capability to selectively inhibit the function or the expression of ABC transporters in cancer stem cells or other tumor cells, represents the main challenge for researcher scientists. A detailed and updated description of the current knowledge on the role of ABC transporters in cancer biology is provided.