Open Access

ARTICLE

Pre-Treatment BOC Expression as an Indicator of Lymphovascular Invasion and In Vitro Chemotherapeutic Response in Upper Tract Urothelial Carcinoma

Yin-Lun Chang^1,2, Hao-Lun Luo¹, Jei-Ming Peng^3,*, Chang-Chun Hsiao^2,*

1 Department of Urology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
2 Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
3 Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan

* Corresponding Authors: Jei-Ming Peng. Email: ; Chang-Chun Hsiao. Email:

Oncology Research 2026, 34(4), 19 https://doi.org/10.32604/or.2026.070837

Received 25 July 2025; Accepted 16 January 2026; Issue published 23 March 2026

Abstract

Background: Upper tract urothelial carcinoma (UTUC) is an aggressive malignancy with high recurrence rates. Lymphovascular invasion (LVI) predicts a poor prognosis, yet its molecular drivers remain unclear. BOC cell adhesion-associated, oncogene-regulated (BOC, also known as Brother of CDO [Cell adhesion molecule-Related/Down-regulated by Oncogenes]), a hedgehog-related cell surface receptor, may serve as a biomarker for tumor progression and chemotherapy response. The study aimed to investigate the role of BOC in UTUC and its potential to predict LVI and chemotherapy response. Methods: Sequencing (RNA-seq) of 10 stage III UTUC, treatment-naïve, fresh tissue samples identified BOC as a candidate biomarker, which was subsequently validated in 2 independent cohorts (n = 74). Functional assays using urothelial carcinoma cell lines assessed the impact of BOC knockdown on cell migration, proliferation, and drug sensitivity. Methylation-specific PCR (MSP) was used to identify potential regulatory sites influencing BOC expression, and immunohistochemistry (IHC) analysis was conducted to compare BOC levels in high- and low-grade bladder cancer. Results: BOC expression was significantly higher in patients with lymphovascular invasion (LVI+, p < 0.01). Knockdown of BOC markedly inhibited cancer cell migration, without affecting proliferation. BOC knockdown enhanced the efficacy of cisplatin and gemcitabine in UTUC cells, although clinical tissue data did not provide direct evidence of its role as a predictor of drug response. Methylation analysis identified key regulatory sites that may control BOC expression, and IHC confirmed increased BOC levels in high-grade bladder cancer, linking it to tumor aggressiveness. Conclusion: BOC may serve as a potential biomarker for predicting LVI and chemotherapy response in UTUC. Its involvement in cancer cell migration and association with high-grade tumors suggests its clinical relevance for prognosis and treatment stratification. Further validation in larger, multi-center studies is warranted.

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Supplementary Material

Supplementary Material File

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