Abstract
Due to the continuous burden of cancer, an extensive research on the factors responsible for an increase in cancer cases and its effective curative measures are utmost essential. Cancer has the potential to resist drug activity resulting in limited chemotherapeutic effectiveness, which leads to mortality in most of the cases. Drug resistance creates a major hurdle in cancer therapy research and can be classified as intrinsic and acquired resistance. Factors which are responsible for developing the resistance are generally present in the oncogenic cells even before chemotherapy, in case of intrinsic resistance, whereas acquired resistance develops during or after chemotherapeutic treatment. Chemoresistance in cancerous cells can be comprehensively ascribed to genetic factors, epigenetic changes as well as tumor microenvironment. This chapter aims to provide a paradigm to understand the factors and mechanisms underlying the cause of resistance to cancer chemotherapeutic drugs. Also, recent strategies to overcome chemoresistance along with novel interventions involving the understanding of molecular signatures of cancer, chemoresistance biomarkers and companion diagnostics have been reviewed. Knowledge thus gained would benefit us in developing effective strategies to help us overcome the burden of chemoresistance in cancerous cells.
Keywords: Apoptosis Inhibition, Cancer Therapies, Chemoresistance, Chemotherapy, Drug resistance, Drug companion diagnostics, DNA repair, Drug transport, Drug targets, Drug metabolism, DNA Methylation, Histone Modification, miRNA, Targeted therapy, Tumor Microenvironment, Mechanisms of chemoresistance, miRNA and cancer, miRNA as biomarker, Novel approaches to overcome chemoresistance.