Oliva Carolina, Carrillo-Beltrán Diego, Osorio Julio C, Gallegos Iván, Carvajal Felipe, Mancilla-Miranda Claudio, Boettiger Paul, Boccardo Enrique, Aguayo Francisco
Laboratorio de Oncovirología, Programa de Virología, Facultad de Medicina, Instituto de Ciencias Biomédicas (ICBM), Universidad de Chile, 8380000, Santiago, Chile.
Departamento de Otorrinolaringología, Hospital Clínico Universidad de Chile, 8380000, Santiago, Chile.
Infect Agent Cancer. 2024 Sep 27;19(1):47. doi: 10.1186/s13027-024-00609-z.
High-risk human papillomaviruses are the causal agents of a subset of head and neck cancers. A previous transcriptomic analysis showed that cIAP2 protein, involved in cell survival and apoptosis, is upregulated in OKF6 oral cells that express HPV16 E6/E7. In addition, cIAP2 promotes radioresistance, a very important concern in HNC treatment. However, cIAP2 increase has not yet been evaluated in oropharyngeal carcinomas (OPCs), nor has been the role of cIAP2 in HNC radioresistance.
We carried out a descriptive-analytical retrospective study in 49 OPCs from Chilean patients. We determined the expression of cIAP2 at transcript and proteins levels using reverse-transcriptase -polymerase chain reaction and immunohistochemistry, respectively. HPV and p16 expression were previously analyzed in these specimens. In addition, SCC-143 HNC cells ectopically expressing HPV16 E6/E7 were analyzed for cIAP2 expression and after transfection with a siRNA for HPV16 E6/E7 knocking down.
We found a statistically significant association between HPV presence and cIAP2 expression (p = 0.0032 and p = 0.0061, respectively). An association between p16 and cIAP2 levels was also found (p = 0.038). When SCC-143 cells were transfected with a construct expressing HPV16 E6/E7, the levels of cIAP2 were significantly increased (p = 0.0383 and p = 0.0115, respectively). Conversely, HPV16 E6 and E7 knocking down resulted in a decrease of cIAP2 levels (p = 0.0161 and p = 0.006, respectively). Finally, cIAP2 knocking down in HPV16 E6/E7 cells resulted in increased apoptosis after exposure to radiation at 4 and 8 Gy (p = 0.0187 and p = 0.0061, respectively).
This study demonstrated for the first time a positive relationship between HPV presence and cIAP2 levels in OPCs. Additionally, cIAP2 knocking down sensitizes HNC cells to apoptosis promoted by radiation. Therefore, cIAP2 is a potential therapeutic target for radiation in HPV-driven HNC.
高危型人乳头瘤病毒是一部分头颈癌的致病因子。先前的转录组分析表明，参与细胞存活和凋亡的cIAP2蛋白在表达HPV16 E6/E7的OKF6口腔细胞中上调。此外，cIAP2可促进放射抗性，这是头颈癌治疗中一个非常重要的问题。然而，cIAP2的增加尚未在口咽癌（OPC）中得到评估，cIAP2在头颈癌放射抗性中的作用也未得到评估。
我们对49例智利患者的OPC进行了描述性分析回顾性研究。我们分别使用逆转录-聚合酶链反应和免疫组织化学在转录水平和蛋白质水平测定cIAP2的表达。这些标本之前已分析过HPV和p16的表达。此外，对异位表达HPV16 E6/E7的SCC-143头颈癌细胞进行cIAP2表达分析，并在用HPV16 E6/E7的小干扰RNA转染以敲低后进行分析。
我们发现HPV的存在与cIAP2表达之间存在统计学上的显著关联（分别为p = 0.0032和p = 0.0061）。还发现p16与cIAP2水平之间存在关联（p = 0.038）。当用表达HPV16 E6/E7的构建体转染SCC-143细胞时，cIAP2水平显著增加（分别为p = 0.0383和p = 0.0115）。相反，HPV16 E6和E7的敲低导致cIAP2水平降低（分别为p = 0.0161和p = 0.006）。最后，在HPV16 E6/E7细胞中敲低cIAP2导致在4 Gy和8 Gy辐射后凋亡增加（分别为p = 0.0187和p = 0.0061）。
本研究首次证明OPC中HPV的存在与cIAP2水平之间存在正相关。此外，敲低cIAP2可使头颈癌细胞对辐射促进的凋亡敏感。因此，cIAP2是HPV驱动的头颈癌放疗的潜在治疗靶点。
