CUL7 通过泛素化降解 MST1 抑制头颈鳞状细胞癌细胞凋亡

CUL7 induces ubiquitination degradation of MST1 to inhibit apoptosis of head and neck squamous cell carcinoma

摘要

目的：探讨 MST1 对头颈鳞状细胞癌（HNSCC）细胞凋亡的影响及相关的机制。方法：采用 Western Blot 法检测癌旁正常组织和 HNSCC 组织中 MST1 蛋白的表达水平；通过慢病毒转导构建过表达 MST1 和敲除 CUL7 的细胞系，划痕实验检测细胞迁移能力，平板克隆形成实验评估细胞克隆形成能力，Calcein‐AM/PI 双染法检测细胞凋亡率；通过裸鼠移植瘤实验评估体内成瘤能力，TUNEL 实验测定肿瘤组织中的细胞凋亡情况。结果：HNSCC 组织中 MST1 表达水平显著低于癌旁正常组织，且其低表达与患者不良预后相关；过表达 MST1 可抑制 CAL27 和 FaDu 细胞的迁移及克隆形成能力，并促进细胞凋亡；CUL7 作为 E3 泛素连接酶介导 MST1 的泛素化降解，敲除 CUL7 可导致 MST1 蛋白积累并诱导肿瘤细胞凋亡；过表达 MST1 可显著促进细胞凋亡并抑制肿瘤生长。结论：CUL7 通过泛素化降解MST1，抑制癌细胞凋亡，进而促进HNSCC 的进展。

Abstract

Objective: To investigate the effect of MST1 on apoptosis in head and neck squamous cell carcinoma (HNSCC) cells and its underlying mechanism. Methods: Western Blot was used to detect the expression of MST1 protein in adjacent normal tissues and HNSCC tissues; lentiviral transduction was employed to construct MST1‐overexpression and CUL7‐knockout cell lines; scratch assay was performed to measure cell migration ability; plate colony formation assay was conducted to determine cancer cell colony formation rate; Calcein‐AM/PI double staining was applied to detect the apoptosis rate. A nude mouse xenograft model was used to assess tumor formation ability in vivo, and TUNEL assay was carried out to determine apoptosis in tumor tissues. Results: The expression level of MST1 in HNSCC tissues was lower than that in adjacent normal tissues, and its low expression indicated poor prognosis in patients; overexpression of MST1 inhibited the migration and colony formation abilities of CAL27 and FaDu cells and promoted apoptosis; CUL7, as an E3 ubiquitin ligase, mediated the ubiquitination and degradation of MST1, and knockout of CUL7 led to the accumulation of MST1 protein and induced tumor cell apoptosis; overexpression of MST1 significantly promoted apoptosis and inhibited tumor growth. Conclusion: CUL7 inhibits cancer cell apoptosis and promotes the progression of HNSCC by ubiquitinating and degrading MST1.

关键词

头颈鳞状细胞癌 / 细胞凋亡 / MST1 / CUL7

Key words

Head and Neck Squamous Cell Carcinoma / Apoptosis / MST1 / CUL7

参考文献

[1] RUFFIN A T, LI H, VUJANOVIC L, et al. Improving head and neck cancer therapies by immunomodulation of the tumour microenvironment[J]. Nat Rev Cancer, 2023, 23(3): 173-188.

[2] VOGLER M, BRAUN Y, SMITH V M, et al. The BCL2 family: From apoptosis mechanisms to new advances in targeted therapy[J]. Signal Transduct Target Ther, 2025, 10(1): 91.

[3] XIAO J, WANG L C, ZHANG B H, et al. Cell death in acute lung injury: Caspase—regulated apoptosis, pyroptosis, necroptosis, and PANoptosis[J]. Front Pharmacol, 2025, 16: 1559659.

[4] TONG X H, TANG R, XIAO M M, et al. Targeting cell death pathways for cancer therapy: Recent developments in necroptosis, pyroptosis, ferroptosis, and cuproptosis research[J]. J Hematol Oncol, 2022, 15(1): 174.

[5] MA S H, MENG Z P, CHEN R, et al. The hippo pathway: Biology and pathophysiology[J]. Annu Rev Biochem, 2019, 88: 577-604.

[6] SAMPSON C, WANG Q P, OTKUR W, et al. The roles of E3 ubiquitin ligases in cancer progression and targeted therapy[J]. Clin Transl Med, 2023, 13(3): e1204.

[7] SHIROMIZU T, YUGE M, KASAHARA K, et al. Targeting E3 ubiquitin ligases and deubiquitinases in ciliopathy and cancer[J]. Int J Mol Sci, 2020, 21(17): E5962.

[8] DAGAR G, KUMAR R, YADAV K K, et al. Ubiquitination and deubiquitination: Implications on cancer therapy[J]. Biochim Biophys Acta BBA Gene Regul Mech, 2023, 1866(4): 194979.

[9] XU J Y, ZHANG Z P, QIAN M Y, et al. Cullin—7 (CUL7) is overexpressed in glioma cells and promotes tumorigenesis via NF—κB activation[J]. J Exp Clin Cancer Res, 2020, 39(1): 59.

[10] SHU B, ZHOU Y X, LEI G Q, et al. TRIM21 is critical in regulating hepatocellular carcinoma growth and response to therapy by altering the MST1/YAP pathway[J]. Cancer Sci, 2024, 115(5): 1476-1491.

[11] ROH K H, LEE Y, YOON J H, et al. TRAF6—mediated ubiquitination of MST1/STK4 attenuates the TLR4—NF—κB signaling pathway in macrophages[J]. Cell Mol Life Sci, 2021, 78(5): 2315-2328.

[12] XU Y N, QU M Y, HE Y X, et al. Smurf1 polyubiquitinates on K285/K282 of the kinases Mst1/2 to attenuate their tumor—suppressor functions[J]. J Biol Chem, 2023, 299(12): 105395.

[13] HUANG Y, ZOU Y, JIE Z. RNF6 promotes the migration and invasion of breast cancer by promoting the ubiquitination and degradation of MST1[J]. Exp Ther Med, 2022, 23(2): 118.

[14] DIAS D C, DOLIOS G, WANG R, et al. CUL7: A DOC domain—containing cullin selectively binds Skp1. Fbx29 to form an SCF—like complex[J]. Proc Natl Acad Sci USA, 2002, 99(26): 16601-16606.

[15] LI Y M, ZANG A M, FU J J, et al. Cullin 7 in tumor development: A novel potential anti—cancer target[J]. Neoplasma, 2021, 68(3): 572-579.

[16] WANG B, ZHOU H, CHEN L, et al. A mitochondria—targeted photosensitizer for combined pyroptosis and apoptosis with NIR—Ⅱ imaging/photoacoustic imaging—guided phototherapy[J]. Angew Chem Int Ed, 2024, 63(39): e202408874.

[17] FU M Y, HU Y, LAN T X, et al. The Hippo signalling pathway and its implications in human health and diseases[J]. Signal Transduct Target Ther, 2022, 7(1): 376.

[18] KUMAR R, HONG W J. Hippo signaling at the hallmarks of cancer and drug resistance[J]. Cells, 2024, 13(7): 564.

[19] ZHOU J, CHEN Q. Poor expression of microRNA—135b results in the inhibition of cisplatin resistance and proliferation and induces the apoptosis of gastric cancer cells through MST1—mediated MAPK signaling pathway[J]. FASEB J, 2019, 33(3): 3420-3436.

[20] CAO J, WEI R J, YAO S K. Matrine has pro—apoptotic effects on liver cancer by triggering mitochondrial fission and activating MST1—JNK signalling pathways[J]. J Physiol Sci, 2019, 69(2): 185-198.

基金资助

国家自然科学基金青年科学基金项目（C 类）(82403450)