Targeting CLIC6 with theaflavin enhances radiotherapy sensitivity in ER+/HER2 − breast cancer - Research findings

Sep 30, 2026

Uploaded by Connor

Radiotherapy is crucial for estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2 −) breast cancer, yet many tumors show intrinsic radioresistance. This study integrates single-cell RNA sequencing and TCGA transcriptomic profiles, applying hdWGCNA to link molecular modules to clinical traits. Chloride intracellular channel 6 (CLIC6) is identified as a key hub gene: CLIC6 overexpression increases radioresistance, while CLIC6 knockdown restores radiosensitivity. Theaflavin binds CLIC6 with high affinity and enhances radiosensitivity in a CLIC6-dependent manner.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages13

Reading Time33 min

AccessFree to download

Introduction

Breast cancer subtype and radioresistance

Rationale for radiosensitizers

CLIC6 and theaflavin

Methods

Integrated scRNA-seq and TCGA analysis (hdWGCNA)

CLIC6 perturbation in ER+ breast cancer cells

Molecular docking

Clonogenic and proliferation assays

Results

hdWGCNA module discovery and CLIC6 hub gene

Effects of CLIC6 on radiosensitivity

Theaflavin binding and radiosensitization specificity

Conclusions

Targeting CLIC6 with theaflavin enhances radiotherapy sensitivity in ER+/HER2 − breast cancer Mengying Suo1, Lin Liu2, Tiantian She3, Chong Chen1 1School of Medicine, Nankai University, Tianjin, China; 2Tianjin Union Medical Center, The First Affiliated Hospital of Nankai University, Tianjin, China; 3School of Medical Technology, Tianjin Medical University, Tianjin, China Contributions: (I) Conception and design: M Suo; (II) Administrative support: T She; (III) Provision of study materials or patients: L Liu, C Chen; (IV) Collection and assembly of data: M Suo; (V) Data analysis and interpretation: M Suo; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors. Correspondence to: Chong Chen, PhD. School of Medicine, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China. [Email: Chongchen@tmu.edu.cn](Email: Chongchen@tmu.edu.cn); Tiantian She, PhD. School of Medical Technology, Tianjin Medical University, No. 22 Qixiangtai Road, Heping District, Tianjin 300070, China. Email: [tiantianshe@tmu.edu.cn](tiantianshe@tmu.edu.cn). Background: Radiotherapy is a cornerstone of breast cancer treatment; however, estrogen receptorpositive (ER+)/human epidermal growth factor receptor 2-negative (HER2 − ) tumors frequently exhibit intrinsic radioresistance. Understanding the molecular mechanisms underlying this resistance is crucial for improving therapeutic outcomes. This study aims to identify key molecular determinants of intrinsic radioresistance in ER+/HER2 − breast cancer and to explore potential radiosensitization strategies targeting these determinants. Methods: We integrated single-cell RNA sequencing (scRNA-seq) data from ER+/HER2 − breast tumors before and after radiotherapy with transcriptomic profiles from The Cancer Genome Atlas (TCGA) . A high-dimensional weighted gene co-expression network analysis (hdWGCNA) was employed to identify gene modules associated with clinical traits. Functional assays were conducted in ER+ breast cancer cells with chloride intracellular channel 6 (CLIC6) overexpression or knockdown. A molecular docking analysis revealed that theaflavin specifically interacts with CLIC6. Further, clonogenic assays and Cell Counting Kit-8 (CCK-8) proliferation assays were performed to validate the biological effects of theaflavin and CLIC6 following radiotherapy. Results: The hdWGCNA identified a luminal A-like gene module correlated with progesterone receptor (PR) positivity and low Ki67 expression, within which CLIC6 emerged as a key hub gene. Elevated CLIC6 expression enhanced radioresistance, whereas CLIC6 knockdown increased radiosensitivity. Molecular docking confirmed that theaflavin binds to CLIC6 with high affinity (binding energy −8.8 kcal/mol) . Theaflavin treatment significantly enhanced radiosensitivity in wild-type and CLIC6-overexpressing cells but had no effect in CLIC6-knockdown or ER-negative (ER −) cells. Conclusions: This study identified CLIC6 as a novel gene associated with radioresistance in ER+/HER2 − breast cancer and showed that theaflavin functions as a natural radiosensitizer in a CLIC6-dependent manner, consistent with its high-affinity interaction with CLIC6. Targeting CLIC6 may provide a promising strategy to enhance radiotherapy efficacy in this common breast cancer subtype. Keywords: Breast cancer; chloride intracellular channel 6 (CLIC6); radiotherapy sensitivity; theaflavin; tumor cell Submitted Nov 08, 2025. Accepted for publication Dec 16, 2025. Published online Dec 29, 2025. doi: 10.21037/tcr-2025-aw-2466 View this article at: [https://dx.doi.org/10.21037/tcr-2025-aw-2466](https://dx.doi.org/10.21037/tcr-2025-aw-2466) © AME Publishing Company. Transl Cancer Res 2025;14(12):9002-9014 | [https://dx.doi.org/10.21037/tcr-2025-aw-2466](https://dx.doi.org/10.21037/tcr-2025-aw-2466) Translational Cancer Research, Vol 14, No 12 December 2025 9003 Introduction Breast cancer is the most comm

FAQs

Why is this study focused on ER+/HER2− breast cancer radiotherapy resistance?

ER+/HER2− tumors commonly exhibit intrinsic radioresistance, which limits radiotherapy benefits. The study aims to uncover molecular determinants that drive this resistance and enable improved treatment outcomes.

How was CLIC6 identified as a key gene?

The study integrated ER+/HER2− single-cell RNA sequencing data before and after radiotherapy with TCGA transcriptomic profiles. hdWGCNA highlighted a luminal A-like module, in which CLIC6 emerged as a hub gene linked to clinical traits.

What role does theaflavin play in relation to CLIC6?

Molecular docking showed theaflavin specifically binds CLIC6 with high affinity. Functional assays demonstrated that theaflavin enhances radiosensitivity in wild-type and CLIC6-overexpressing cells, but not when CLIC6 is knocked down or when ER is negative.

Sep 30, 2026

Uploaded by Connor