iNOS regulates the therapeutic response of pancreatic cancer cells to radiation therapy.
- 作者列表："Pereira PMR","Edwards KJ","Mandleywala K","Carter LM","Escorcia FE","Campesato LF","Cornejo M","Abma L","Mohsen AA","Iacobuzio-Donahue CA","Merghoub T","Lewis JS
:Pancreatic ductal adenocarcinoma (PDAC) is highly resistant to radiation therapy (RT), chemotherapy, or a combination of these modalities, and surgery remains the only curative intervention for localized disease. Although cancer-associated fibroblasts (CAFs) are abundant in PDAC tumors, the effects of RT on CAFs and the response of PDAC cells to RT are unknown. Using patient samples and orthotopic PDAC biological models we showed that RT increased inducible nitric oxide synthase (iNOS) in the tumor tissues. Mechanistic in vitro studies showed that, although undetectable in RT-activated tumor cells, iNOS expression and nitric oxide (NO) secretion were significantly increased in CAFs secretome following RT. Culture of PDAC cells with conditioned media from RT-activated CAFs increased iNOS/NO signaling in tumor cells through nuclear factor kappa B (NFĸB), which in turn elevated the release of inflammatory cytokines by the tumor cells. Increased NO after RT in PDAC contributed to an acidic microenvironment that was detectable using the radiolabeled pH (low) insertion peptide (pHLIP®). In murine orthotopic PDAC models, pancreatic tumor growth was delayed when iNOS inhibition was combined with RT. These data show the important role that iNOS/NO signaling plays in the effectiveness of RT to treat PDAC tumors.
: 胰腺导管腺癌 (PDAC) 对放射治疗 (RT) 、化疗或这些方式的组合高度耐药，手术仍然是局部疾病的唯一治愈性干预。虽然癌症相关成纤维细胞 (CAFs) 在 PDAC 肿瘤中含量丰富，但 RT 对 CAFs 的影响以及 PDAC 细胞对 RT 的反应尚不清楚。使用患者样本和原位 PDAC 生物学模型，我们发现 RT 增加肿瘤组织中的诱导型一氧化氮合酶 (iNOS)。机制体外研究表明，虽然在 RT 激活的肿瘤细胞中检测不到，但 RT 后 CAFs 分泌组 iNOS 表达和一氧化氮 (NO) 分泌显著增加。用 RT 激活的 CAFs 的条件培养基培养 PDAC 细胞通过核因子 κ B (nf B B) 增加肿瘤细胞中的 iNOS/NO 信号。这反过来又提高了肿瘤细胞释放的炎性细胞因子。PDAC 中 RT 后 NO 的增加有助于使用放射性标记的 pH (低) 插入肽 (pHLIP) 检测到酸性微环境®)。在小鼠原位 PDAC 模型中，当 iNOS 抑制与 RT 联合使用时，胰腺肿瘤生长延迟。这些数据显示了 iNOS/NO 信号在 RT 治疗 PDAC 肿瘤有效性中的重要作用。
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.