Araujo-Gutierrez R, Van Eps J L, Kirui D, Bryan N S, Kang Y, Fleming J B, Fernandez-Moure J S
Department of Heart Failure & Transplant Cardiology, Houston Methodist Research Institute, 6565 Fannin St. F657, Houston, TX, 77030, USA.
Department of Surgery, Houston Methodist Hospital, 6550 Fannin St. Sm1661, Houston, TX, 77030, USA.
Biomed Microdevices. 2019 Feb 21;21(1):23. doi: 10.1007/s10544-019-0375-z.
Gemcitabine (GEM) is the first-line treatment for pancreatic adenocarcinoma (PAC) yet chemoresistance is common. Nitric oxide (NO) is the predominant species responsible for the cytotoxic action of macrophages against cancer cells yet localized delivery is difficult given the short half-life. We sought to study the effect of locally delivered NO on GEM mediated PAC cytotoxicity and the potential role of SMAD4 in this effect. We hypothesized that NO would enhance the cytotoxicity of GEM in a SMAD4 dependent manner. NO-Silica nanoparticles (NO-Si) were synthesized via a co-condensation of tetraethoxysilane with aminoalkoxysilane under high-pressure nitrous oxide. NO release was measured using chemiluminescence. A SMAD4 negative PAC cell line (SMAD4-) was made using retroviral knockdown of Panc1 PAC cells. Panc1 and SMAD4- cells were treated with gemcitabine (100 nm (hi) to 30 μm (lo)), 30 mg NOSi particles, or both (NOSi or NOSi) and cell viability assessed. NoSi reduced cell viability by 25.99% in Panc1 and 24.38% in SMAD4-. When combined with gemcitabine, further reductions were seen in a dose dependent manner for both cell lines. We have demonstrated the in-vitro dose dependent cytotoxic effects of NOSi. When combined with GEM there is a synergistic effect resulting in improved cytotoxicity seen in both Panc1 and SMAD4- PAC cells with a differential pattern of cell death seen at high concentrations of NO. These findings suggest not only that NO is useful chemosensitizing agent but that SMAD4- may play a role in its synergism with GEM.
吉西他滨（GEM）是胰腺腺癌（PAC）的一线治疗药物，但化疗耐药很常见。一氧化氮（NO）是巨噬细胞对癌细胞产生细胞毒性作用的主要物质，但由于半衰期短，局部递送很困难。我们试图研究局部递送的NO对GEM介导的PAC细胞毒性的影响以及SMAD4在这种影响中的潜在作用。我们假设NO会以SMAD4依赖的方式增强GEM的细胞毒性。通过在高压一氧化二氮下将四乙氧基硅烷与氨基烷氧基硅烷共缩合合成了NO-二氧化硅纳米颗粒（NO-Si）。使用化学发光法测量NO释放。通过逆转录病毒敲低Panc1 PAC细胞制备了SMAD4阴性PAC细胞系（SMAD4-）。用吉西他滨（100纳米（高）至30微米（低））、30毫克NO-Si颗粒或两者（NO-Si或NO-Si）处理Panc1和SMAD4-细胞，并评估细胞活力。NO-Si使Panc1细胞活力降低25.99%，使SMAD4-细胞活力降低24.38%。当与吉西他滨联合使用时，两种细胞系均呈剂量依赖性进一步降低。我们已经证明了NO-Si的体外剂量依赖性细胞毒性作用。当与GEM联合使用时，会产生协同效应，导致Panc1和SMAD4- PAC细胞的细胞毒性均得到改善，在高浓度NO下观察到不同的细胞死亡模式。这些发现不仅表明NO是一种有用的化学增敏剂，而且表明SMAD4-可能在其与GEM的协同作用中发挥作用。
