Reciprocal Regulation Between Forkhead Box M1/NF-kB and Methionine Adenosyltransferase 1A Drives Liver Cancer.
叉头盒 M1/NF-kB 和甲硫氨酸腺苷转移酶 1A 之间的相互调节驱动肝癌。
- 作者列表："Li Y","Lu L","Tu J","Zhang J","Xiong T","Fan W","Wang J","Li M","Chen Y","Steggerda J","Peng H","Chen Y","Li TWH","Zhou ZG","Mato JM","Seki E","Liu T","Yang H","Lu SC
:Forkhead box M1 (FOXM1) and NF-ĸB are oncogenic drivers in liver cancer that positively regulate each other. We showed that methionine adenosyltransferase 1A (MAT1A) is a tumor suppressor in the liver and it inhibits NF-ĸB activity. Here we examined the interplay between FOXM1/NF-kB and MAT1A in liver cancer. We examined gene and protein expression, effects on promoter activities and binding of proteins to promoter regions, effects of FOXM1 inhibitors T0901317 (T0) and FDI-6 in vitro and in xenograft and syngeneic models of liver cancer. We found in both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) an induction in FOXM1 and NF-κB expression is accompanied by fall in MATα1 (protein encoded by MAT1A). The TCGA dataset confirmed the inverse correlation between FOXM1 and MAT1A. Interestingly, FOXM1 directly interact with MATα1 and they negatively regulate each other. In contrast, FOXM1 positively regulates p50 and p65 expression via MATα1, as the effect is lost in its absence. FOXM1, MATα1 and NF-κB all bind to the FOX-binding sites in the FOXM1 and MAT1A promoters. However, binding of FOXM1 and NF-κB repressed MAT1A promoter activity but activated FOXM1 promoter. In contrast, binding of MATα1 repressed FOXM1 promoter. MATα1 also binds and represses the NF-κB element in the presence of p65 or p50. Inhibiting FOXM1 with either T0 or FDI-6 inhibited liver cancer cell growth in vitro and in vivo. However, inhibiting FOXM1 had minimal effects in liver cancer cells that do not express MAT1A. CONCLUSION: We have unveiled a novel crosstalk between FOXM1/NF-κB and MAT1A. Upregulation in FOXM1 lowers MAT1A but raises NF-κB expression and this is a feed forward loop that enhances tumorigenesis.
: 叉头框 M1 (FOXM1) 和 NF-ĸB 是肝癌中相互正向调节的致癌驱动因子。我们发现甲硫氨酸腺苷转移酶 1A (MAT1A) 是肝脏中的肿瘤抑制因子，它抑制 NF-b 活性。这里我们检测了 FOXM1/NF-kB 和 MAT1A 在肝癌中的相互作用。我们检测了基因和蛋白表达，对启动子活性的影响和蛋白与启动子区域的结合，FOXM1 抑制剂 T0901317 (T0) 的影响并在肝癌的体外、移植瘤及同基因模型中 FDI-6。我们在肝细胞癌 (HCC) 和胆管癌 (CCA) 中均发现 FOXM1 和 NF-κ b 表达的诱导伴随着 matα 1 (MAT1A 编码的蛋白) 的下降。TCGA 数据集证实了 FOXM1 和 MAT1A 之间的负相关。有趣的是，FOXM1 直接与 matα 1 相互作用，它们相互负调节。相比之下，FOXM1 通过 matα 1 正向调节 p50 和 p65 的表达，因为在不存在的情况下这种作用会消失。FOXM1 、 matα 1 和 NF-κ b 都与 FOXM1 和 MAT1A 启动子中的 FOX 结合位点结合。然而，FOXM1 和 NF-κ b 的结合抑制了 MAT1A 启动子活性，但激活了 FOXM1 启动子。相比之下，matα 1 的结合抑制了 FOXM1 启动子。Matα 1 在 p65 或 p50 存在的情况下也结合并抑制 NF-κ b 元件。用 T0 或 FDI-6 抑制 FOXM1 在体内外抑制肝癌细胞生长。然而，抑制 FOXM1 在不表达 MAT1A 的肝癌细胞中作用最小。结论: 我们揭示了 FOXM1/NF-κ b 和 MAT1A 之间的新型串扰。FOXM1 的上调降低 MAT1A，但升高 NF-κ b 的表达，这是一个增强肿瘤发生的前馈环。
METHODS::Aims: Radiotherapy is predominantly used as one of the treatment modalities to treat local tumor in colorectal cancer (CRC). Hindrance in disease treatment can be attributed to radio-tolerance of cancer stem cells (CSCs) subsistence in the tumor. Understanding the radio-resistant property of CSCs might help in the accomplishment of targeted radiotherapy treatment and increased disease-free survival. Telomeric RAP1 contributes in modulation of various transcription factors leading to aberrant cell proliferation and tumor cell migration. Therefore, we investigated the role of RAP1 in maintaining resistance phenotype and acquired stemness in radio-resistant cells.Main Methods: Characterization of HCT116 derived radio-resistant cell (HCT116RR) was performed by cell survival and DNA damage profiling. RAP1 silenced cells were investigated for DNA damage and expression of CSC markers through western blotting and Real-time PCR post-irradiation. Molecular docking and co-immunoprecipitation study were performed to investigate RAP1 and KLF4 interaction followed by RAP1 protein status profiling in CRC patient.Key findings: We established radio-resistant cells, which showed tolerance to radiotherapy and elevated expression of CSC markers along with RAP1. RAP1 silencing showed enhanced DNA damage and reduced expression of CSC markers post-irradiation. We observed strong physical interaction between RAP1 and KLF4 protein. Furthermore, higher RAP1 expression was observed in the tumor of CRC patients. Dataset analysis also revealed that high expression of RAP1 expression is associated with poor prognosis.Significance: We conclude that higher expression ofRAP1 implicates its possible role in promoting radio-resistance in CRC cells by modulating DNA damage and CSC phenotype.
METHODS::Cancer stem-like cells are rare immortal cells within tumor, which are thought to play important roles in ionizing radiation (IR) therapy-resistance. Quercetin is a natural flavonoid with potential anti-cancer properties without significant cytotoxicity in normal tissues. In this study, we demonstrated that quercetin-IR combination treatment exhibited more dramatic anti-cancer effect than either quercetin or IR treatment alone via targeting colon cancer stem cells (CSCs) and inhibiting the Notch-1 signaling. These effects were further verified by in vivo studies which showed remarkable decrease of the CSCs markers and the expression of Notch-1 signaling proteins in human colon cancer xenografts in nude mice. Co-treatment with quercetin and low dose of radiation significantly reduced the expressions of all five proteins of γ-secretase complex in HT-29 and DLD-1 cells. In addition, ectopic expression of the Notch intracellular domain (NICD) partly reversed the inhibition effects by the combination therapy. In conclusion, our results indicated that the combination of quercetin (20 μM) and IR (5Gy) might be a promising therapeutic strategy for colon cancer treatment by targeting colon cancer stem-like cells and inhibiting the Notch-1 signaling. In future studies, we intend to further explore the potential therapeutic efficacy of the quercetin-radiation combination treatment in clinical trials.
METHODS:OBJECTIVES:Long-term prevention of metastatic disease remains a challenge in locally advanced rectal cancer, and robust pretreatment prognostic factors for metastatic progression are lacking. We hypothesized that detecting circulating tumor-specific DNA (ctDNA) based on hypermethylation of the neuropeptide Y gene (meth-ctDNA) could be a prognostic marker in the neoadjuvant setting; we examined this in a secondary, explorative analysis of a prospective trial. MATERIALS AND METHODS:Serum samples were prospectively collected in a phase III trial for locally advanced rectal cancer. Positivity for and fractional abundance of meth-ctDNA in baseline samples were estimated. Overall survival (OS) and the rate of distant metastases were compared between meth-ctDNA positive and negative patients; other prognostic factors were controlled for in multivariate Cox regression. Importance of quantitative load was examined by considering the fractional abundance of meth-ctDNA relative to total circulating DNA. RESULTS:Baseline serum samples were available for 146 patients. In total, 30 patients had presence of meth-ctDNA, with no correlation with cT (P=0.8) or cN (P=0.6) stages. Median follow-up was 10.6 years for OS and 5.1 years for freedom from distant metastases. Patients with meth-ctDNA had significantly worse 5-year OS (47% vs. 69%), even when controlling for other prognostic factors (hazard ratio=2.08; 95% confidence interval, 1.23-1.51). This seemed mainly driven by disparity in the rate of distant metastases (55% vs. 72% at 5 y, P=0.01); hazard ratio=2.20 (95% confidence interval, 1.19-4.07, P=0.01) in multivariate analysis. Increased quantitative load was highly significant for worse outcomes. CONCLUSIONS:Meth-ctDNA could be a potential prognostic marker in the neoadjuvant setting and may, if validated, identify patients at increased risk of distant metastases.