PO.IM01.11 · 免疫学
TRIB2调控抗雄激素耐药性及神经内分泌前列腺癌中的免疫逃逸
TRIB2 regulates immune evasion in antiandrogen-resistant and neuroendocrine prostate cancer
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：恩杂鲁胺（Enzalutamide）耐药仍是晚期前列腺癌的一项主要临床挑战。我们此前发现Tribbles同源物2（TRIB2）在恩杂鲁胺耐药前列腺癌（ERPC）中高度上调，包括神经内分泌（NE）型耐药肿瘤，其中TRIB2驱动肿瘤细胞存活、谱系可塑性和治疗耐药。靶向TRIB2可抑制耐药细胞的生长，凸显了其在疾病进展中的关键作用。免疫检查点分子，包括B7-H3（CD276）和PD-L1（CD274），在ERPC和NE前列腺肿瘤中也升高，并促成T细胞介导的抗肿瘤免疫受损。这些趋同的发现使我们假设，TRIB2促进治疗耐药性前列腺癌中的免疫逃逸，而抑制TRIB2可能增强T细胞介导的抗肿瘤免疫。
方法：使用恩杂鲁胺耐药（C4-2B ENZR和LNCaP ENZR）和NE（NCI-H660）前列腺癌细胞系研究TRIB2依赖性的免疫调节。使用慢病毒shRNA敲低、质粒介导的过表达或使用选择性TRIB2抑制剂TBI-001进行药理学抑制来调节TRIB2的表达。使用蛋白质印迹（western blot）和流式细胞术检测B7-H3和PD-L1的表达。将改造后的癌细胞与活化的人CD8⁺ T细胞共培养，并使用标准免疫学检测评估T细胞激活、细胞因子产生和细胞毒性。
结果：TRIB2敲低和TBI-001处理均显著降低了ERPC和NE前列腺癌细胞中B7-H3和PD-L1的表达，而TRIB2过表达则增加了免疫检查点水平。TRIB2抑制增强了CD8⁺ T细胞的激活和细胞因子分泌（IFN-gamma和TNF-alpha），并改善了T细胞介导的针对耐药癌细胞的细胞毒性。相反，TRIB2水平升高的细胞强烈抑制了T细胞的激活和细胞毒性。免疫检查点阻断部分恢复了针对TRIB2高表达细胞的T细胞功能，联合阻断在恢复抗肿瘤免疫方面显示出增强的效果。
结论：这些发现表明，TRIB2通过上调免疫检查点蛋白和抑制抗肿瘤T细胞活性，促进了恩杂鲁胺耐药性和神经内分泌前列腺癌中的免疫逃逸。这代表了TRIB2通过肿瘤内在效应和肿瘤微环境调节这两种方式驱动治疗耐药性前列腺癌进展的双重机制。对TRIB2-免疫检查点轴的治疗性靶向代表了一种克服恩杂鲁胺耐药的合理策略，兼具抑制肿瘤生长和恢复有效抗肿瘤免疫的双重益处。
查看英文原文 English abstract
Background: Enzalutamide resistance remains a major clinical challenge in advanced prostate cancer. We previously identified Tribbles homolog 2 (TRIB2) as highly upregulated in enzalutamide-resistant prostate cancer (ERPC), including neuroendocrine (NE)-type resistant tumors, where it drives tumor cell survival, lineage plasticity, and therapeutic resistance. Targeting TRIB2 suppresses the growth of resistant cells, highlighting its critical role in disease progression. Immune checkpoint molecules, including B7-H3 (CD276) and PD-L1 (CD274), are also elevated in ERPC and NE prostate tumors and contribute to impaired T cell-mediated anti-tumor immunity. These convergent findings led us to hypothesize that TRIB2 promotes immune evasion in treatment-resistant prostate cancer and that its inhibition may enhance T-cell-mediated anti-tumor immunity.
Methods: Enzalutamide-resistant (C4-2B ENZR and LNCaP ENZR ) and NE (NCI-H660) prostate cancer cell lines were used to investigate TRIB2-dependent immune regulation. TRIB2 expression was modulated using lentiviral shRNA knockdown, plasmid-mediated overexpression, or pharmacological inhibition using the selective TRIB2 inhibitor TBI-001. B7-H3 and PD-L1 expression was measured using western blot and flow cytometry. Modified cancer cells were co-cultured with activated human CD8⁺ T-cells, and T-cell activation, cytokine production, and cytotoxicity were evaluated using standard immunological assays.
Results: Both TRIB2 knockdown and TBI-001 treatment markedly reduced B7-H3 and PD-L1 expression in ERPC and NE prostate cancer cells, whereas TRIB2 overexpression increased immune checkpoint levels. TRIB2 inhibition enhanced CD8⁺ T-cell activation and cytokine secretion (IFN-gamma and TNF-alpha), and improved T cell-mediated cytotoxicity against resistant cancer cells. Conversely, cells with elevated TRIB2 levels strongly suppressed T-cell activation and cytotoxicity. Immune checkpoint blockade partially restored T-cell function against TRIB2-high cells, with combined blockade showing enhanced effects in restoring anti-tumor immunity.
Conclusion: These findings demonstrate that TRIB2 facilitates immune evasion in enzalutamide-resistant and neuroendocrine prostate cancer by upregulating immune checkpoint proteins and suppressing anti-tumor T-cell activity. This represents a dual mechanism by which TRIB2 drives treatment-resistant prostate cancer progression through both tumor-intrinsic effects and modulation of the tumor microenvironment. Therapeutic targeting of the TRIB2-immune checkpoint axis represents a rational strategy to overcome enzalutamide resistance, offering the combined benefit of inhibiting tumor growth while restoring effective anti-tumor immunity.
利益披露 Disclosure
S. K. Suthar, None..
A. Rahman, None..
S. Lee, None..
J. Monga, None.