期刊
ENDOCRINE-RELATED CANCER
卷 22, 期 5, 页码 777-792出版社
BIOSCIENTIFICA LTD
DOI: 10.1530/ERC-14-0302
关键词
anaplastic thyroid carcinoma; HDAC; RhoB; BIM; p21
资金
- National Institute of Health and Medical Research [R01CA136665]
- Florida Department of Health Bankhead-Coley Cancer Research Program [FL09B202]
- Francis and Miranda Childress Foundation Fund for Cancer Research
- John A and Bette B Klacsmann Fund for Cancer Research at Mayo Clinic in Florida
- Betty G Castigliano Fund in Cancer Research Honoring S Gordon Castigliano, MD cancer research at Mayo Clinic Florida
Anaplastic thyroid carcinoma is a highly aggressive undifferentiated carcinoma with a mortality rate near 100% due to an assortment of genomic abnormalities which impede the success of therapeutic options. Our laboratory has previously identified that RhoB upregulation serves as a novel molecular therapeutic target and agents upregulating RhoB combined with paclitaxel lead to antitumor synergy. Knowing that histone deacetylase 1 (HDAC1) transcriptionally suppresses RhoB, we sought to extend our findings to other HDACs and to identify the HDAC inhibitor (HDACi) that optimally synergize with paclitaxel. Here we identify HDAC6 as a newly discovered RhoB repressor. By using isoform selective HDAC inhibitors (HDACi) and shRNAs, we show that RhoB has divergent downstream signaling partners, which are dependent on the HDAC isoform that is inhibited. When RhoB upregulates only p21 (cyclin kinase inhibitor) using a class I HDACi (romidepsin), cells undergo cytostasis. When RhoB upregulates BIMEL using class II/(I) HDACi (belinostat or vorinostat), apoptosis occurs. Combinatorial synergy with paclitaxel is dependent upon RhoB and BIMEL while upregulation of RhoB and only p21 blocks synergy. This bifurcated regulation of the cell cycle by RhoB is novel and silencing either p21 or BIMEL turns the previously silenced pathway on, leading to phenotypic reversal. This study intimates that the combination of belinostat/vorinostat with paclitaxel may prove to be an effective therapeutic strategy via the novel observation that class II/(I) HDACi antagonize HDAC6-mediated suppression of RhoB and subsequent BIMEL, thereby promoting antitumor synergy. These overall observations may provide a mechanistic understanding of optimal therapeutic response.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据