The Spliceosome Scaffold Component BCAS2 Promotes Pancreatic Cancer Progression through Weak 5 Splice Site Dependent Splicing Regulation
- 1Stony Brook University
Abstract
Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest malignancies. Dysregulated RNA splicing has emerged as a critical mechanism contributing to PDAC progression. However, whether structural components of the spliceosome regulate oncogenic alternative splicing was not known. Here, we identify the nineteen complex (NTC) component BCAS2/SPF27 as a critical regulator of PDAC progression. Elevated expression of BCAS2 in PDAC is associated with poor patient outcomes. Transcriptomic analyses revealed that BCAS2 specifically regulates alternative exons with weak splice sites. In particular, BCAS2 promotes SOS1 exon 21 inclusion and consequently RAC-signaling activation. Furthermore, splice-switching antisense oligonucleotide (ASO) mediated skipping of SOS1 exon 21 suppressed PDAC proliferation and migration. Our findings uncover a role of BCAS2 in the regulation of weak splice site usage and identify the BCAS2/SOS1/RAC signaling axis as a potential therapeutic vulnerability in pancreatic cancer.
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BibTeX
@misc{wan2026spliceosome,
title = {{The Spliceosome Scaffold Component BCAS2 Promotes Pancreatic Cancer Progression through Weak 5 Splice Site Dependent Splicing Regulation}},
author = {L. Wan and M. Wang and Y. Ishigami and A. J. Kral and K.-T. Lin and J. R. Merrill and S. K. Lyons and A. R. Krainer},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.06.757127},
url = {https://www.biorxiv.org/content/10.64898/2026.10.06.757127v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - The Spliceosome Scaffold Component BCAS2 Promotes Pancreatic Cancer Progression through Weak 5 Splice Site Dependent Splicing Regulation
AU - L. Wan
AU - M. Wang
AU - Y. Ishigami
AU - A. J. Kral
AU - K.-T. Lin
AU - J. R. Merrill
AU - S. K. Lyons
AU - A. R. Krainer
PY - 2026
DA - 2026/10/06
PB - bioRxiv
DO - 10.64898/2026.10.06.757127
UR - https://www.biorxiv.org/content/10.64898/2026.10.06.757127v1
AB - Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest malignancies. Dysregulated RNA splicing has emerged as a critical mechanism contributing to PDAC progression. However, whether structural components of the spliceosome regulate oncogenic alternative splicing was not known. Here, we identify the nineteen complex (NTC) component BCAS2/SPF27 as a critical regulator of PDAC progression. Elevated expression of BCAS2 in PDAC is associated with poor patient outcomes. Transcriptomic analyses revealed that BCAS2 specifically regulates alternative exons with weak splice sites. In particular, BCAS2 promotes SOS1 exon 21 inclusion and consequently RAC-signaling activation. Furthermore, splice-switching antisense oligonucleotide (ASO) mediated skipping of SOS1 exon 21 suppressed PDAC proliferation and migration. Our findings uncover a role of BCAS2 in the regulation of weak splice site usage and identify the BCAS2/SOS1/RAC signaling axis as a potential therapeutic vulnerability in pancreatic cancer.
ER -