CRISPR-Cas9 HDR system enhances AQP1 gene expression.

Zhimin Wang,Kelly J Shields,Songling Wang,Qingshi Liu,Zhenguo Cheng,Baoli Hu,Na Zhang,Yaohe Wang,Michael J Passineau,Li-Rong Zhang

doi:10.18632/oncotarget.22901

Abstract

Ionizing radiation (IR) isthe primarytherapeutic tool to treat patients with cancerous lesions located in the head and neck. In many patients, IR results in irreversible and severe salivary gland dysfunction or xerostomia. Currently there are no effective treatment options to reduce the effects of xerostomia. More recently, salivary gland gene therapy utilizing the water-specific protein aquaporin 1 (AQP1) has been of great interest to potentially correct salivary dysfunction. In this study, we used CRISPR-Cas9 gene editing along with the endogenous promoter of AQP1 within theHEK293 and MDCK cell lines. The successful integration of the cytomegalovirus (CMV) promoterresultedin a significant increase of AQP1 gene transcription and translation. Additionalfunctional experiments involvingthe MDCK cell line confirmedthat over-expressed AQP1increasedtransmembrane fluid flux indicative of increased intracellular fluid flux. The off-target effect of designed guided RNA sequence was analyzed and demonstrateda high specificity for the Cas9 cleavage. Considering the development of new methods for robust DNA knock-in, our results suggest that endogenous promoter replacement may be a potential treatment forsalivary gland dysfunction.

Highlights

Each year in the United States there are an estimated 40,000 cases of head and neck cancer
We found the sorting efficiency to be similar for the three separate guide RNA (gRNA) sequences (Figure 2A)
We expanded on this concept by using a CMV promotor to successfully increase aquaporin 1 (AQP1) transcription and protein levels in both the Human Embryonic Kidney-293 (HEK293) and Madin-Darby Canine Kidney Epithelial (MDCK) stable cell lines

Summary

Introduction

Each year in the United States there are an estimated 40,000 cases of head and neck cancer. For the majority of these patients, ionizing radiation is a fundamental element of therapy; the patientsoften suffer from the impairment of normal salivary gland function [1, 2, 3]. The salivary glands play important roles in oral health aiding in food digestion and protecting oral mucosa. Manycancer patients experience a dramatic decrease in the quality of life. Our research targets the restoration of normal salivary gland function to improve the quality of life for these cancer survivors [3, 4]. Prescription medications and moisturizers are available to reduce side-effects of the ionizing radiation on salivary gland function. Current areas of research www.impactjournals.com/oncotarget to restore normal salivary gland function include1) regeneration,2) the use of ultrasound-assisted gene therapy (UAGT) targeting aquaporin (AQP1), and 3) epigenetic modifications. Current areas of research www.impactjournals.com/oncotarget to restore normal salivary gland function include1) regeneration,2) the use of ultrasound-assisted gene therapy (UAGT) targeting aquaporin (AQP1), and 3) epigenetic modifications. [5, 6, 7, 8, 9, 10, 11]

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