Life science
Medical & healthcare, Drug development

Investigation of novel mechanisms in the sarcomagenesis andhematogenous metastasis of uterine leiomyosarcoma
Department of Obstetrics and Gynecology, Graduate School of Medicine
Assistant Professor Michiko Kodama

https://researchmap.jp/mkyh

Professor Tadashi Kimura

https://researchmap.jp/read0106368

Life science

Abstract
Uterine leiomyosarcoma (ULMS) is a highly aggressive malignant tumor with rapid growth and hematogenous metastasis, andthe prognosis is extremely poor. There is no standard treatment
other than surgery.
In this study, we performed sleeping beauty (SB) transposon
screening, a comprehensive cancer gene identification method using immunocompetent mice, and identified several candidate driver genes (CGCs) for ULMS development and hematogenous metastasis from ULMS. Zfp217, a zinc finger protein with the highest
frequency of transposon insertions among 19 genes considered
to be involved in sarcomagenesis of ULMS, and Nrd1, encoding
nardilysin, considered to be involved in metastatic lung tumors,
were validated as oncogenes in human ULMS. The CGCs catalog
including these genes can be therapeutic targets in human ULMS.

▍ Significance of the research and Future perspective
There are no large-scale gene profile data sets for ULMS due toits rarity, thereby hampering the development of new therapeutics
based on its pathogenesis. Our findings of CGCs involved in thepathogenesis and progression of ULMS may lead to the development of novel therapeutic strategies.

▍ Background & Results
ULMS is an extremely aggressive malignant tumor with rapid
growth and high metastatic potential and has a very poor prognosis because of its resistance to chemotherapy and radiation therapy. Due to its rarity, drug discovery for ULMS is challenging fromthe problems of validation and funding. In this study, we performed
a forward genetic screening, which is a powerful tool for discovering novel therapeutic targets for various cancers, using the SB
transposon, in which random insertional mutagenesis of transposons is repeated genome-wide in target organs in mice.
Mice with uterine myometrial-specific Pten deletion and Kras
activation did not develop uterine tumors, however when further
SB transposon insertions occurred, most developed ULMS between 2-3 months of age (Fig.1, 2). Tumor DNA was analyzed by
next-generation sequencing to identify transposon insertion sites,and a list of 19 CGCs associated with sarcomagenesis was compiled. Among them, Zfp217, one of zinc finger proteins, showed
highest frequency of transposon insertions. ZNF217, human homolog of Zfp217, was found to be expressed at the protein level inhuman ULMS, and ZNF217 suppression inhibited cell proliferationand migration in human ULMS cell lines, and its overexpression
promoted these capacities. Because of the rapid growth of theuterine tumors, it was impossible to observe hematogenous metastasis until it occurred. Hence, lung metastasis model was createdby establishing cell lines from mouse tumors and injecting themthrough the tail vein of immunocompetent mice. One of the CGCs,Nrd1, encoding nardilysin, was identified in the lung metastaticlesions. NRDC, human homolog of Nrd1, was expressed in human
ULMS metastatic tissue at the protein level, indicating that it functioned as an oncogene. These results indicate that the CGCs catalog identified by SB transposon screening is useful for elucidating
the pathogenesis and metastasis mechanisms of human ULMS.

Fig.1

Fig.2

P a t e n t
Tr e a t i s e

Kodama, Michiko; Shimura, Hiroko; Kimura, Tadashi et al. Sleeping Beauty Transposon Mutagenesis Identifies Genes Driving the Initiation and Metastasisof Uterine Leiomyosarcoma. Cancer Res. 2021, 81, p. 5413-5424, doi: 10.1158/0008-5472.CAN-21-0356

URL
K e y w o r d uterine leiomyosarcoma, forward genetic screening, sleeping beauty transposon