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.
