Bongiovanni Laura, Andriessen Anneloes, Silvestri Serenella, Porcellato Ilaria, Brachelente Chiara, de Bruin Alain
Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.
Department of Veterinary Medicine, University of Perugia, Perugia, Italy.
Front Vet Sci. 2021 Aug 16;8:705359. doi: 10.3389/fvets.2021.705359. eCollection 2021.
Uncontrolled proliferation is a key feature of tumor progression and malignancy. This suggests that cell-cycle related factors could be exploited as cancer biomarkers and that pathways specifically involved in the cell cycle, such as the Rb-E2F pathway, could be targeted as an effective anti-tumor therapy. We investigated 34 formalin-fixed paraffin-embedded (FFPE) tissue samples of canine cutaneous melanocytoma, cutaneous melanoma, and oral melanoma. Corresponding clinical follow-up data were used to determine the prognostic value of the mRNA expression levels of several cell cycle regulated E2F target genes (E2F1, DHFR, CDC6, ATAD2, MCM2, H2AFZ, GINS2, and survivin/BIRC5). Moreover, using four canine melanoma cell lines, we explored the possibility of blocking the Rb-E2F pathway by using a CDK4/6 inhibitor (Palbociclib) as a potential anti-cancer therapy. We investigated the expression levels of the same E2F target gene transcripts before and after treatment to determine the potential utility of these molecules as predictive markers. The E2F target gene H2AFZ was expressed in 91.43% of the primary tumors and H2AFZ expression was significantly higher in cases with unfavorable clinical outcome. Among the other tested genes, survivin/BIRC5 showed as well-promising results as a prognostic marker in canine melanoma. Three of the four tested melanoma cell lines were sensitive to the CDK4/6 inhibitor. The resistant cell line displayed higher expression levels of H2AFZ before treatment compared to the CDK4/6 inhibitor-sensitive cell lines. The present results suggest that CDK4/6 inhibitors could potentially be used as a new anti-cancer treatment for canine melanoma and that H2AFZ could serve as a prognostic and predictive marker for patient selection.
不受控制的增殖是肿瘤进展和恶性肿瘤的一个关键特征。这表明细胞周期相关因子可被用作癌症生物标志物，并且特定参与细胞周期的通路，如Rb-E2F通路，可作为有效的抗肿瘤治疗靶点。我们研究了34份犬皮肤黑素细胞瘤、皮肤黑色素瘤和口腔黑色素瘤的福尔马林固定石蜡包埋（FFPE）组织样本。利用相应的临床随访数据来确定几种细胞周期调节的E2F靶基因（E2F1、DHFR、CDC6、ATAD2、MCM2、H2AFZ、GINS2和survivin/BIRC5）的mRNA表达水平的预后价值。此外，我们使用四种犬黑色素瘤细胞系，探索了使用CDK4/6抑制剂（帕博西尼）阻断Rb-E2F通路作为潜在抗癌治疗的可能性。我们研究了治疗前后相同E2F靶基因转录本的表达水平，以确定这些分子作为预测标志物的潜在效用。E2F靶基因H2AFZ在91.43%的原发性肿瘤中表达，并且在临床结果不佳的病例中H2AFZ表达显著更高。在其他测试基因中，survivin/BIRC5作为犬黑色素瘤的预后标志物也显示出有前景的结果。四种测试的黑色素瘤细胞系中有三种对CDK4/6抑制剂敏感。与CDK4/6抑制剂敏感的细胞系相比，耐药细胞系在治疗前显示出更高的H2AFZ表达水平。目前的结果表明，CDK4/6抑制剂可能潜在地用作犬黑色素瘤的一种新的抗癌治疗方法，并且H2AFZ可作为患者选择的预后和预测标志物。
