MCL-1 antagonism enhances the anti-invasive effects of dasatinib in pancreatic adenocarcinoma.
- 作者列表："Castillo L","Young AIJ","Mawson A","Schafranek P","Steinmann AM","Nessem D","Parkin A","Johns A","Chou A","Law AMK","Lucas MC","Murphy KJ","Deng N","Gallego-Ortega D","Caldon CE","Australian Pancreatic Cancer Genome Initiative (APGI).","Timpson P","Pajic M","Ormandy CJ","Oakes SR
:Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest malignancies. It is phenotypically heterogeneous with a highly unstable genome and provides few common therapeutic targets. We found that MCL1, Cofilin1 (CFL1) and SRC mRNA were highly expressed by a wide range of these cancers, suggesting that a strategy of dual MCL-1 and SRC inhibition might be efficacious for many patients. Immunohistochemistry revealed that MCL-1 protein was present at high levels in 94.7% of patients in a cohort of PDACs from Australian Pancreatic Genome Initiative (APGI). High MCL1 and Cofilin1 mRNA expression was also strongly predictive of poor outcome in the TCGA dataset and in the APGI cohort. In culture, MCL-1 antagonism reduced the level of the cytoskeletal remodeling protein Cofilin1 and phosphorylated SRC on the active Y416 residue, suggestive of reduced invasive capacity. The MCL-1 antagonist S63845 synergized with the SRC kinase inhibitor dasatinib to reduce cell viability and invasiveness through 3D-organotypic matrices. In preclinical murine models, this combination reduced primary tumor growth and liver metastasis of pancreatic cancer xenografts. These data suggest that MCL-1 antagonism, while reducing cell viability, may have an additional benefit in increasing the antimetastatic efficacy of dasatinib for the treatment of PDAC.
: 胰腺导管腺癌 (PDAC) 仍然是最致命的恶性肿瘤之一。它具有表型异质性，基因组高度不稳定，提供了很少的共同治疗靶点。我们发现 MCL1 、 Cofilin1 (CFL1) 和 SRC mRNA 在这些癌症中高表达，提示双重 MCL-1 和 SRC 抑制策略可能对许多患者有效。免疫组织化学显示，在来自澳大利亚胰腺基因组计划 (APGI) 的 PDACs 队列中，94.7% 的患者存在高水平的 MCL-1 蛋白。在 TCGA 数据集和 APGI 队列中，高 MCL1 和 Cofilin1 mRNA 表达也强烈预测不良结局。在培养中，MCL-1 拮抗作用降低了活性 Y416 残基上细胞骨架重塑蛋白 Cofilin1 和磷酸化 SRC 的水平，提示侵袭能力降低。MCL-1 拮抗剂 S63845 与 SRC 激酶抑制剂达沙替尼协同作用，通过 3d 器官型基质降低细胞活力和侵袭力。在临床前小鼠模型中，这种组合减少了胰腺癌移植瘤的原发肿瘤生长和肝转移。这些数据表明，MCL-1 拮抗作用在降低细胞活力的同时，可能会增加达沙替尼治疗 PDAC 的抗转移疗效。
METHODS::Pancreatic ductal adenocarcinoma (PDAC) is a disease of aging. The TP53 gene product regulates cell growth, aging, and cancer. To determine the important targets of TP53 in PDAC, we examined the expression of 440 proteins on a reverse phase protein array (RPPA) in PDAC-derived MIA-PaCa-2 cells which either had WT-TP53 or lacked WT-TP53. MIA-PaCa-2 cells have a TP53 mutation as well as mutant KRAS and represent a good in vitro model to study PDAC. RPPA analysis demonstrated expression of tumor promoting proteins in cells that lacked WT-TP53; and this feature could be reversed significantly when the cells were transfected with vector encoding WT-TP53 or treated with berberine or a modified berberine (BBR). Expression of miR-34a-associated signaling was elevated in cells expressing WT-TP53 compared to cells expressing mTP53. Results from in vivo studies using human PDAC specimens confirmed the in vitro results as the expression of miR-34a and associated signaling was significantly decreased in PDAC specimens compared to non-cancerous tissues. This study determined SERPINE1 as a miR-34a target with relevance to the biology of PDAC. Thus, we have identified a key target (SERPINE1) of the TP53/miR-34a axis that may serve as a potential biomarker for early detection of pancreatic cancer.
METHODS::Background: SLC6A14 (ATB0,+), a Na+/Cl-coupled transporter for neutral/cationic amino acids, is overexpressed in many cancers; It has been investigated as a target for improved liposomal drug delivery to treat liver cancer.Research design and methods: Here we explored the mechanism of ATB0,+-mediated entry of such liposomes. As ATB0,+ is highly-expressed in pancreatic cancer, we also examined the therapeutic utility of ATB0,+-targeted liposomal drug delivery to treat this cancer.Results: The uptake of lysine-conjugated liposomes (LYS-LPs) was greater in ATB0,+-positive MCF7 cells. The uptake process consisted of two steps: binding and internalization. The binding of LYS-LPs to MCF7 cells was higher than that of bare liposomes, and the process was dependent on Na+ and Cl-, and inhibitable by ATB0,+ substrates or blocker. In contrast, the internalization step was independent of lysine. The cellular entry of LYS-LPs facilitated by ATB0,+ occurred via endocytosis with transient endosomal degradation of ATB0,+ protein with subsequent recovery. Moreover, LYS-LPs also enhanced the uptake and cytotoxicity of gemcitabine in these cells in an ATB0,+-dependent manner.Conclusions: We conclude that ATB0,+ could be exploited for targeted drug delivery in the form of lysine-conjugated liposomes and that the approach represents a novel strategy for enhanced pancreatic cancer therapy.
METHODS:PURPOSE:Pre-operative prediction of histological response to neoadjuvant therapy aids decisions regarding surgical management of borderline resectable pancreatic cancer (BRPC). We elucidate correlation between pre-/post-treatment whole-tumor apparent diffusion coefficient (ADC) value and rate of tumor cell destruction. We newly verify whether post-treatment ADC value at the site of vascular contact predicts R0 resectability of BRPC. METHODS:We prospectively reviewed 28 patients with BRPC who underwent diffusion-weighted magnetic resonance imaging before neoadjuvant chemotherapy and surgery. Correlation between the percentage of tumor cell destruction and various parameters was analyzed. Strong parameters were assessed for their ability to predict therapeutic histological response and R0 resectability. RESULTS:Pre-/post-treatment whole-tumor ADC value correlated with tumor cell destruction rate by all parameters (R = 0.630/0.714, P 50% was determined at 1.40 × 10-3 mm2/s. It predicts histological response with 100% sensitivity, 81% specificity, and 89% accuracy. It predicts R0 with 88% sensitivity, 70% specificity, and 75% accuracy. CONCLUSIONS:Post-treatment whole-tumor ADC value may be a predictor of R0 resectability in patients with BRPC. Tumor cell destruction rate is indicated by the difference between pre-/post-treatment ADC values. This difference is strongly affected by the pre-treatment ADC value. The cutoff value of ADC at the site of vascular contact could not discriminate R0 resectability.