CDK4/6 Inhibition Induces Senescence and Enhances Radiation Response by Disabling DNA Damage Repair in Oral Cavity Squamous Cell Carcinoma.
CDK4/6 Inhibition Induces Senescence and Enhances Radiation Response by Disabling DNA Damage Repair in Oral Cavity Squamous Cell Carcinoma.
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人乳头瘤病毒阴性 (HPV(−)) 口腔鳞状细胞癌 (OCSCC) 是头颈癌死亡的主要原因。放射抵抗仍然是 OCSCC 治疗失败的主要原因。总体而言，未能治愈局部晚期 OCSCC 仍然是一个艰巨的挑战。我们研究的目的是利用 p16 模拟 palbociclib 靶向 HPV(−) OCSCC 中过度活跃的 CDK4/6 轴，并评估由此产生的对辐射敏感性的影响。我们的研究表明，同源重组（HR）和非同源末端连接途径（NHEJ）这两种关键的DNA损伤修复途径在哌柏西利诱导OCSCC细胞衰老后均受到损害，从而导致放射敏感性增强。我们的研究结果为 OCSCC 的有前途的治疗范例提供了重要的见解。目的：HPV(−) OCSCC 抵抗放射治疗。编码 p16INK4A 的 CDKN2A 基因在 OCSCC 中通常被破坏。 p16 抑制 CDK4/CDK6，导致细胞周期停滞，但 OCSCC 中 CDK4/6 抑制的生物学后遗症仍未得到充分研究。本研究探讨了 CDK4/6 的抑制是否会增强 OCSCC 的放射反应。方法：在 OCSCC 细胞系 HN5 和 CAL27 经 Palbociclib 处理后进行 MTT 测定。在放射（RT-2 或 4Gy）、palbociclib (P)（0.5 µM 或 1 µM）或同时联合治疗（P+RT）后分析克隆生存和协同作用。对 DNA 损伤/修复和衰老进行了检查。通过 siRNA 靶向 CDK4/6 以证实 P+RT 效应。建立源自患者肿瘤的三维永生化球体和类器官（条件重编程 OCSCC CR-06 和 CR-18），以进一步检查和验证对 P+RT 的反应。结果：P+RT 表现出活力和协同作用降低，β-gal 表达增加（约 95%），γH2AX 约高两倍。 P+RT 后 Rad51 和 Ku80 降低，表明 HR 和 NHEJ 均受损。 siCDK4/6 通过辐射加速衰老。 P+RT 后球体的增殖和大小均减少。 CR-06 和 CR-18 进一步证明，P+RT 后增殖和类器官大小减少了三倍。结论：靶向 CDK4/6 与放疗联合治疗 OCSCC 可以通过诱导衰老和抑制 DNA 损伤修复来提高疗效。
Human papilloma virus–negative (HPV(−)) oral cavity squamous cell carcinoma (OCSCC) is the leading cause of mortality amongst head and neck cancers. Radiation resistance remains a prime cause of treatment failure in OCSCC. Overall, failure to cure locally advanced OCSCC remains a formidable challenge. The aim of our study was to exploit the hyperactive CDK4/6 axis in HPV(−) OCSCC by targeting it with the p16 mimetic palbociclib and to assess the resulting effect on susceptibility to radiation. Our study demonstrates that both homologous recombination (HR) and Non-homologous end joining pathway (NHEJ), two critical DNA damage repair pathways, are compromised after palbociclib-induced senescence in OCSCC cells, leading to enhance radiation sensitivity. Our findings provide important insight towards a promising treatment paradigm in OCSCC. Purpose: HPV(−) OCSCC resists radiation treatment. The CDKN2A gene, encoding p16INK4A, is commonly disrupted in OCSCC. p16 inhibits CDK4/CDK6, leading to cell cycle arrest, but the biological sequelae of CDK4/6 inhibition in OCSCC remains understudied. This study examines whether inhibition of CDK4/6 enhances radiation response in OCSCC. Methods: MTT assays were performed in OCSCC cell lines HN5 and CAL27 following treatment with palbociclib. Clonogenic survival and synergy were analyzed after radiation (RT-2 or 4Gy), palbociclib (P) (0.5 µM or 1 µM), or concurrent combination treatment (P+RT). DNA damage/repair and senescence were examined. CDK4/6 were targeted via siRNA to corroborate P+RT effects. Three-dimensional immortalized spheroids and organoids derived from patient tumors (conditionally reprogrammed OCSCC CR-06 and CR-18) were established to further examine and validate responses to P+RT. Results: P+RT demonstrated reduced viability and synergy, increased β-gal expression (~95%), and ~two-fold higher γH2AX. Rad51 and Ku80 were reduced after P+RT, indicating impairment of both HR and NHEJ. siCDK4/6 increased senescence with radiation. Spheroids showed reduced proliferation and size with P+RT. CR-06 and CR-18 further demonstrated three-fold reduced proliferation and organoids size with P+RT. Conclusion: Targeting CDK4/6 can lead to improved efficacy when combined with radiation in OCSCC by inducing senescence and inhibiting DNA damage repair.
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DOI：
10.1158/1541-7786.mcr-20-0915
发表时间：
2021-05
期刊：
Molecular cancer research : MCR
影响因子：
--
作者：
Gadsden NJ;Fulcher CD;Li D;Shrivastava N;Thomas C;Segall JE;Prystowsky MB;Schlecht NF;Gavathiotis E;Ow TJ
通讯作者：
Ow TJ
影响因子：
50.3
作者：
Anders L;Ke N;Hydbring P;Choi YJ;Widlund HR;Chick JM;Zhai H;Vidal M;Gygi SP;Braun P;Sicinski P
通讯作者：
Sicinski P
影响因子：
158.5
作者：
Bernier, J;Domenge, C;van Glabbeke, M
通讯作者：
van Glabbeke, M
影响因子：
78.5
作者：
Bernier, J;Hall, EJ;Giaccia, A
通讯作者：
Giaccia, A
影响因子：
19
作者：
Goel S;DeCristo MJ;McAllister SS;Zhao JJ
通讯作者：
Zhao JJ