TY - JOUR
T1 - Splice-switching of the insulin receptor pre-mRNA alleviates tumorigenic hallmarks in rhabdomyosarcoma
AU - Khurshid, Safiya
AU - Montes, Matias
AU - Comiskey, Daniel F.
AU - Shane, Brianne
AU - Matsa, Eleftheria
AU - Jung, Francesca
AU - Brown, Chelsea
AU - Bid, Hemant Kumar
AU - Wang, Ruoning
AU - Houghton, Peter J.
AU - Roberts, Ryan
AU - Rigo, Frank
AU - Chandler, Dawn
N1 - Funding Information:
This work was funded by NCI grant R21CA195324, an OSU Pelotonia Idea Award, and foundation grants from the Elsa U. Pardee Foundation, The Sunbeam Foundation, and Cancer Free Kids (to D.S. Chandler) as well as OSU Pelotonia fellowships (to S. Khurshid, M. Montes, and D.F. Comiskey). We would like to thank Dr. Nick Webster (UC San Diego School of Medicine) for his kind contribution to IR splicing minigene constructs. We want to thank the mouse pathology core at Abigail Wexner Research Institute Nationwide Children’s Hospital and especially Melissa Sammons for her technical expertise and help with the mouse angiogenesis experiments. We would like to thank the histology core at Abigail Wexner Research Institute Nationwide Children’s Hospital for help with mouse histology. We would also like to thank the members of the Chandler lab for their critical review of the paper.
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12
Y1 - 2022/12
N2 - Rhabdomyosarcoma (RMS) is an aggressive pediatric tumor with a poor prognosis for metastasis and recurrent disease. Large-scale sequencing endeavors demonstrate that Rhabdomyosarcomas have a dearth of precisely targetable driver mutations. However, IGF-2 signaling is known to be grossly altered in RMS. The insulin receptor (IR) exists in two alternatively spliced isoforms, IR-A and IR-B. The IGF-2 signaling molecule binds both its innate IGF-1 receptor as well as the insulin receptor variant A (IR-A) with high affinity. Mitogenic and proliferative signaling via the canonical IGF-2 pathway is, therefore, augmented by IR-A. This study shows that RMS patients express increased IR-A levels compared to control tissues that predominantly express the IR-B isoform. We also found that Hif-1α is significantly increased in RMS tumors, portraying their hypoxic phenotype. Concordantly, the alternative splicing of IR adapts to produce more IR-A in response to hypoxic stress. Upon examining the pre-mRNA structure of the gene, we identified a potential hypoxia-responsive element, which is also the binding site for the RNA-binding protein CUG-BP1 (CELF1). We designed Splice Switching Oligonucleotides (SSO) against this binding site to decrease IR-A levels in RMS cell lines and, consequently, rescue the IR-B expression levels. SSO treatment resulted in a significant reduction in cell proliferation, migration, and angiogenesis. Our data shows promising insight into how impeding the IGF-2 pathway by reducing IR-A expression mitigates tumor growth. It is evident that Rhabdomyosarcomas use IR alternative splicing as yet another survival strategy that can be exploited as a therapeutic intervention in conjunction with already established anti-IGF-1 receptor therapies.
AB - Rhabdomyosarcoma (RMS) is an aggressive pediatric tumor with a poor prognosis for metastasis and recurrent disease. Large-scale sequencing endeavors demonstrate that Rhabdomyosarcomas have a dearth of precisely targetable driver mutations. However, IGF-2 signaling is known to be grossly altered in RMS. The insulin receptor (IR) exists in two alternatively spliced isoforms, IR-A and IR-B. The IGF-2 signaling molecule binds both its innate IGF-1 receptor as well as the insulin receptor variant A (IR-A) with high affinity. Mitogenic and proliferative signaling via the canonical IGF-2 pathway is, therefore, augmented by IR-A. This study shows that RMS patients express increased IR-A levels compared to control tissues that predominantly express the IR-B isoform. We also found that Hif-1α is significantly increased in RMS tumors, portraying their hypoxic phenotype. Concordantly, the alternative splicing of IR adapts to produce more IR-A in response to hypoxic stress. Upon examining the pre-mRNA structure of the gene, we identified a potential hypoxia-responsive element, which is also the binding site for the RNA-binding protein CUG-BP1 (CELF1). We designed Splice Switching Oligonucleotides (SSO) against this binding site to decrease IR-A levels in RMS cell lines and, consequently, rescue the IR-B expression levels. SSO treatment resulted in a significant reduction in cell proliferation, migration, and angiogenesis. Our data shows promising insight into how impeding the IGF-2 pathway by reducing IR-A expression mitigates tumor growth. It is evident that Rhabdomyosarcomas use IR alternative splicing as yet another survival strategy that can be exploited as a therapeutic intervention in conjunction with already established anti-IGF-1 receptor therapies.
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U2 - 10.1038/s41698-021-00245-5
DO - 10.1038/s41698-021-00245-5
M3 - Article
C2 - 35017650
AN - SCOPUS:85122789874
SN - 2397-768X
VL - 6
JO - npj Precision Oncology
JF - npj Precision Oncology
IS - 1
M1 - 1
ER -