**Author details**

Aditi-Singh- Address all correspondence to: aditi.ucsd@gmail.com Independent Scientist, USA-

**Gene Silencing Applications** 

**Chapter 2**

**Provisional chapter**

**CRISPR-ERA for Switching Off (Onco) Genes**

Ignacio García-Tuñon, Elena Vuelta, Sandra Pérez-Ramos, Jesús M Hernández-Rivas, Lucía Méndez, María Herrero

technology for gene silencing and its application in gene therapy.

**1. Gene suppression therapies in cancer: an overview**

research, as well as of clinical activities (**Table 1**) [2].

**CRISPR-ERA for Switching Off (Onco) Genes**

DOI: 10.5772/intechopen.80245

Genome-editing nucleases like the popular CRISPR/Cas9 enable the generation of knockout cell lines and null zygotes by inducing site-specific double-stranded breaks (DSBs) within a genome. In most cases, when a DNA template is not present, the DSB is repaired by nonhomologous end joining (NHEJ), resulting in small nucleotide insertions or deletions that can be used to construct knockout alleles. However, for several reasons, these mutations do not produce the desired null result in all cases, instead generating a similar protein with functional activity. This undesirable effect could limit the therapeutic efficiency of gene therapy strategies focused on abrogating oncogene expression by CRISPR/ Cas9 and should be taken into account. This chapter reviews the irruption of CRISPR

**Keywords:** gene therapy, knockout, null allele, oncogene silencing, CRISPR technology,

Gene therapy, which was initially developed for the treatment of genetic (primarily monogenic) diseases, has mainly focused on cancer therapy, so that more than 65% of all gene therapy trials worldwide (**Figure 1**) are aimed at the treatment of solid and hematological malignancies [1]. As a consequence, cancer gene therapy is a predominant field of basic

Various strategies at different molecular levels (**Figure 2**) have been employed to treat malignant diseases in recent decades, such as specific drug inhibitors acting at the protein level,

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

Ignacio García-Tuñon, Elena Vuelta,

Lucía Méndez, María Herrero and

and Manuel Sanchez-Martin

http://dx.doi.org/10.5772/intechopen.80245

Manuel Sanchez-Martin

**Abstract**

gene suppression

Sandra Pérez-Ramos, Jesús M Hernández-Rivas,

Additional information is available at the end of the chapter

Additional information is available at the end of the chapter
