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World J Gastrointest Surg. Nov 27, 2026; 18(11): 121769
Published online Nov 27, 2026. doi: 10.4240/wjgs.121769
Expression and role of the long noncoding RNA Linc00909 in chemoradiotherapy for colorectal cancer
Yong Wu, Yi-Yi Zhang, Bing-Jie Guan, Hua-Jun Cai, Guo-Xian Guan
Yong Wu, Yi-Yi Zhang, Hua-Jun Cai, Guo-Xian Guan, Department of Colorectal Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian Province, China
Yong Wu, Yi-Yi Zhang, Hua-Jun Cai, Guo-Xian Guan, Department of Colorectal Surgery, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, Fujian Province, China
Bing-Jie Guan, Department of Radiation Oncology, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian Province, China
Bing-Jie Guan, Department of Radiation Oncology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, Fujian Province, China
Author contributions: Wu Y, Zhang YY, and Guan BJ contributed to methodology, data curation, formal analysis, and visualization; Cai HJ contributed to writing - original draft; Cai HJ and Guan GX contributed to supervision and conceptualization; and Guan GX contributed to writing - review and editing. All authors have read and approved the final version of the manuscript and agree to be accountable for all aspects of the work.
AI contribution statement: No AI tools were used in the preparation of this manuscript.
Supported by the Fujian Provincial Health Technology Project, No. 2023QNA038; Joint Funds for the Innovation of Science and Technology, Fujian Province, No. 2020Y9125; and the Fujian Province Finance Project, No. BPB-2023GGX.
Institutional review board statement: This study was approved by the Ethics Committee of the First Affiliated Hospital of Fujian Medical University (approval No. MTCA, ECFAH of FMU [2015]084-2).
Institutional animal care and use committee statement: This study was approved by the Laboratory Animal Ethics Committee of Fujian Medical University (approval No. 2023-Y-0706).
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines.
Data sharing statement: All the data generated and analyzed during this study are included in this published article.
Corresponding author: Guo-Xian Guan, MD, Professor, Department of Colorectal Surgery, The First Affiliated Hospital of Fujian Medical University, No. 20 Chazhong Road, Taijiang District, Fuzhou 350005, Fujian Province, China.
fjxhggx@163.com
Received: April 1, 2026
Revised: August 6, 2026
Accepted: October 16, 2026
Published online: November 27, 2026
Processing time: 225 Days and 14.6 Hours
BACKGROUND
Colorectal cancer is one of the major malignant tumors worldwide. Previous studies have shown that long noncoding RNAs have significant effects on various human cancers, but the underlying molecular mechanisms remain unclear.
AIM
To investigate the impact of the long noncoding RNA Linc00909 on colorectal cancer and its molecular mechanism.
METHODS
Using 196 paired colorectal cancer and adjacent tissues from 30 patients with rectal cancer (19 resistant, 11 sensitive) to neoadjuvant chemoradiotherapy, we assessed Linc00909 expression using real-time quantitative polymerase chain reaction and correlated it with survival outcomes. Functional assays in Linc00909-overexpressing SW620 and DLD1 cells—including Cell Counting Kit-8 assays, flow cytometry, and sphere formation—evaluated proliferation, cell cycle, apoptosis, stemness, and 5-fluorouracil/radiotherapy sensitivity. Tumorigenicity was examined in vivo. Bioinformatic and molecular experiments explored Linc00909’s competing endogenous RNA mechanism.
RESULTS
Linc00909 was upregulated in resistant and tumor tissues and independently predicted poorer overall and disease-free survival. Linc00909 overexpression enhanced proliferation, colony formation, antiapoptotic capacity, stemness, and therapy resistance in vitro and promoted tumor growth in vivo. miR-625-5p was bioinformatically predicted and experimentally validated as a binding target of Linc00909, with its expression decreasing upon Linc00909 overexpression. SOX2 was identified as a downstream target of miR-625-5p and showed increased expression at both the messenger RNA and protein levels following Linc00909 upregulation.
CONCLUSION
Linc00909 can affect the proliferation, colony formation, apoptosis, cell cycle regulation, spheroid-forming ability, and sensitivity of colorectal cancer cells to 5-fluorouracil and radiotherapy. Mechanistically, Linc00909 may regulate the expression of the downstream target gene SOX2 by sequestering miR-625-5p, thereby influencing the sensitivity of colorectal cancer cells to radiotherapy and chemotherapy. Therefore, Linc00909 can be considered a potential therapeutic target for treating colorectal cancer.
Core Tip: Linc00909 is elevated in therapy-resistant and tumor tissues of colorectal cancer and serves as an independent indicator of inferior overall and disease-free survival. Its overexpression promotes proliferation, clonogenicity, apoptosis evasion, stem-like traits, and resistance to 5-fluorouracil and radiotherapy in vitro, while accelerating tumor growth in vivo. Mechanistically, Linc00909 sponges miR-625-5p, thereby relieving repression of SOX2 and activating a Linc00909/miR-625-5p/SOX2 axis that drives therapeutic resistance. This axis is a candidate target for improving colorectal cancer treatment.
