Gene amplification during myogenic differentiation.

Ulrike Fischer,Abdulrahman Raslan,Nicole Ludwig,Carola Meier,Eckart Meese

doi:10.18632/oncotarget.6845

Abstract

Gene amplifications are mostly an attribute of tumor cells and drug resistant cells. Recently, we provided evidence for gene amplifications during differentiation of human and mouse neural progenitor cells. Here, we report gene amplifications in differentiating mouse myoblasts (C2C12 cells) covering a period of 7 days including pre-fusion, fusion and post-fusion stages. After differentiation induction we found an increase in copy numbers of CDK4 gene at day 3, of NUP133 at days 4 and 7, and of MYO18B at day 4. The amplification process was accompanied by gamma-H2AX foci that are indicative of double stand breaks. Amplifications during the differentiating process were also found in primary human myoblasts with the gene CDK4 and NUP133 amplified both in human and mouse myoblasts. Amplifications of NUP133 and CDK4 were also identified in vivo on mouse transversal cryosections at stage E11.5. In the course of myoblast differentiation, we found amplifications in cytoplasm indicative of removal of amplified sequences from the nucleus. The data provide further evidence that amplification is a fundamental mechanism contributing to the differentiation process in mammalians.

Highlights

For almost 30 years gene amplifications have been known in the development of amphibians and flies [1]
We analyzed C2C12 cells (ATCC), which represent a subclone generated from a mouse myoblast cell line [5, 6]
It was previously shown that alpha-actin (ACTA1) and MYO18B expression increased during myogenic differentiation [13, 14]

Summary

Introduction

For almost 30 years gene amplifications have been known in the development of amphibians and flies [1]. We recently reported gene amplifications during differentiation in human and mouse neural stem and progenitor cells [2, 3]. These studies raise the questions if gene amplification is a fundamental and widespread mechanism during the differentiation process. To further address this issue we searched for amplification during the differentiation of the skeletal muscle. C2C12 cells derived from a mouse myoblast cell line [5, 6] were used in many studies that analyzed myogenic differentiation [7,8,9]. Fork collapse at stalled replication forks play a role in the formation of double strand breaks [11] and both double strand breaks and fork collapse are likely accompanying the amplification process

Methods

Results

Conclusion