Elevated levels of lamin A promote HR and NHEJ-mediated repair mechanisms in etoposide-treated ovarian cancer cells

Abstract

Lamins are emerging as major regulators in the maintenance of nuclear architecture and genome organization. Extensive research for the last two decades has enormously contributed to understanding the roles of lamins in various signaling mechanisms which are drastically modified in neoplasia. It is interesting to record that alteration in lamin A/C expression and distribution drives tumorigenesis of almost all tissues of human bodies. One of the important signatures of a cancer cell is its inability to repair DNA damage which befalls several genomic events that transform the cells to be sensitive to chemotherapeutic agents. This genomic and chromosomal instability is the most common feature found in cases of high-grade ovarian serous carcinoma. Here, we report elevated levels of lamins in OVCAR3 cells (High grade ovarian serous carcinoma cell line) in comparison to IOSE (Immortalised ovarian surface epithelial cells) and consequently altered damage repair machinery in OVCAR3. We have analyzed the changes in global gene expression as a sequel to DNA damage induced by etoposide in ovarian carcinoma where lamin A is particularly elevated in expression and reported some differentially expressed genes associated with pathways conferring cellular proliferation and chemoresistance. We highlight new avenues unraveling the role of upregulated lamin A in confronting chemically induced genomic instability in the context of high grade ovarian serous cancer through a combination of HR and NHEJ mechanisms.