State Key Laboratory of Systems Medicine for Cancer, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, Shanghai Cancer Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
Pediatric Translational Medicine Institute, Department of Hematology & Oncology, Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, 200127, China.
Mol Cancer. 2024 Mar 22;23(1):60. doi: 10.1186/s12943-024-01975-3.
Cancer stem-like cell is a key barrier for therapeutic resistance and metastasis in various cancers, including breast cancer, yet the underlying mechanisms are still elusive. Through a genome-wide lncRNA expression profiling, we identified that LINC00115 is robustly upregulated in chemoresistant breast cancer stem-like cells (BCSCs).
LncRNA microarray assay was performed to document abundance changes of lncRNAs in paclitaxel (PTX)-resistant MDA-MB-231 BCSC (ALDH) and non-BCSC (ALDH). RNA pull-down and RNA immunoprecipitation (RIP) assays were performed to determine the binding proteins of LINC00115. The clinical significance of the LINC00115 pathway was examined in TNBC metastatic lymph node tissues. The biological function of LINC00115 was investigated through gain- and loss-of-function studies. The molecular mechanism was explored through RNA sequencing, mass spectrometry, and the CRISPR/Cas9-knockout system. The therapeutic potential of LINC00115 was examined through xenograft animal models.
LINC00115 functions as a scaffold lncRNA to link SETDB1 and PLK3, leading to enhanced SETDB1 methylation of PLK3 at both K106 and K200 in drug-resistant BCSC. PLK3 methylation decreases PLK3 phosphorylation of HIF1α and thereby increases HIF1α stability. HIF1α, in turn, upregulates ALKBH5 to reduce mA modification of LINC00115, resulting in attenuated degradation of YTHDF2-dependent mA-modified RNA and enhanced LINC00115 stability. Thus, this positive feedback loop provokes BCSC phenotypes and enhances chemoresistance and metastasis in triple-negative breast cancer. SETDB1 inhibitor TTD-IN with LINC00115 ASO sensitizes PTX-resistant cell response to chemotherapy in a xenograft animal model. Correlative expression of LINC00115, methylation PLK3, SETDB1, and HIF1α are prognostic for clinical triple-negative breast cancers.
Our findings uncover LINC00115 as a critical regulator of BCSC and highlight targeting LINC00115 and SETDB1 as a potential therapeutic strategy for chemotherapeutic resistant breast cancer.
癌症干细胞样细胞是多种癌症（包括乳腺癌）治疗耐药和转移的关键障碍，但潜在机制仍不清楚。通过全基因组长非编码 RNA 表达谱分析，我们发现 LINC00115 在紫杉醇耐药乳腺癌干细胞样细胞（BCSCs）中强烈上调。
进行 lncRNA 微阵列分析以记录紫杉醇（PTX）耐药 MDA-MB-231 BCSC（ALDH）和非 BCSC（ALDH）中 lncRNA 的丰度变化。进行 RNA 下拉和 RNA 免疫沉淀（RIP）测定以确定 LINC00115 的结合蛋白。在三阴性乳腺癌转移性淋巴结组织中检查 LINC00115 通路的临床意义。通过增益和失能研究研究 LINC00115 的生物学功能。通过 RNA 测序、质谱和 CRISPR/Cas9 敲除系统探索分子机制。通过异种移植动物模型检查 LINC00115 的治疗潜力。
LINC00115 作为支架 lncRNA 与 SETDB1 和 PLK3 结合，导致耐药 BCSC 中 PLK3 的 K106 和 K200 上 SETDB1 甲基化增强。PLK3 甲基化降低 PLK3 对 HIF1α 的磷酸化，从而增加 HIF1α 的稳定性。反过来，HIF1α 上调 ALKBH5 以减少 LINC00115 的 mA 修饰，导致 YTHDF2 依赖性 mA 修饰 RNA 的降解减弱和 LINC00115 稳定性增强。因此，这种正反馈环引发 BCSC 表型并增强三阴性乳腺癌的化疗耐药性和转移。在异种移植动物模型中，SETDB1 抑制剂 TTD-IN 与 LINC00115 ASO 联合使用可增强紫杉醇耐药细胞对化疗的反应。LINC00115、甲基化 PLK3、SETDB1 和 HIF1α 的相关表达可预测临床三阴性乳腺癌的预后。
我们的研究结果揭示了 LINC00115 作为 BCSC 的关键调节剂，并强调了靶向 LINC00115 和 SETDB1 作为治疗化疗耐药性乳腺癌的潜在治疗策略。
