The effects of many anticancer drugs are unfortunately masked by drug resistance developed by several
tumors. This represents a strong and major challenge in cancer research. Drug resistance is due to several factors,
including membrane transporters taking out drugs from the cell, molecular mechanisms repairing or inhibiting the
damage caused by the drugs, mutations in anticancer drug targets, or even anatomic structures affecting either
drug penetration or elimination. Here we will review the molecular aspects of therapy resistance mechanisms.
Research on the inhibition of proteins involved in drug resistance or design of new anticancer drugs overcoming
such mechanisms with no doubt will result in a major advancement in cancer treatment.
Keywords: Drug resistance, multidrug resistance, ABC transporters, tamoxifen, antibodies, EGFR mutations.
