Al-Mamun M A, Farid D M, Ravenhil L, Hossain M A, Fall C, Bass R
Department of Population Medicine & Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA.
Department of Computer Science & Engineering, United International University, Bangladesh.
J Theor Biol. 2016 Jan 7;388:37-49. doi: 10.1016/j.jtbi.2015.10.007. Epub 2015 Oct 21.
Most cancer treatments efficacy depends on tumor metastasis suppression, where tumor suppressor genes play an important role. Maspin (Mammary Serine Protease Inhibitor), an non-inhibitory serpin has been reported as a potential tumor suppressor to influence cell migration, adhesion, proliferation and apoptosis in in vitro and in vivo experiments in last two decades. Lack of computational investigations hinders its ability to go through clinical trials. Previously, we reported first computational model for maspin effects on tumor growth using artificial neural network and cellular automata paradigm with in vitro data support. This paper extends the previous in silico model by encompassing how maspin influences cell migration and the cell-extracellular matrix interaction in subcellular level. A feedforward neural network was used to define each cell behavior (proliferation, quiescence, apoptosis) which followed a cell-cycle algorithm to show the microenvironment impacts over tumor growth. Furthermore, the model concentrates how the in silico experiments results can further confirm the fact that maspin reduces cell migration using specific in vitro data verification method. The data collected from in vitro and in silico experiments formulates an unsupervised learning problem which can be solved by using different clustering algorithms. A density based clustering technique was developed to measure the similarity between two datasets based on the number of links between instances. Our proposed clustering algorithm first finds the nearest neighbors of each instance, and then redefines the similarity between pairs of instances in terms of how many nearest neighbors share the two instances. The number of links between two instances is defined as the number of common neighbors they have. The results showed significant resemblances with in vitro experimental data. The results also offer a new insight into the dynamics of maspin and establish as a metastasis suppressor gene for further molecular research.
大多数癌症治疗的疗效取决于对肿瘤转移的抑制,其中肿瘤抑制基因起着重要作用。在过去二十年中,人组织蛋白酶抑制剂(Mammary Serine Protease Inhibitor,maspin),一种非抑制性丝氨酸蛋白酶抑制剂,已被报道为一种潜在的肿瘤抑制因子,在体外和体内实验中可影响细胞迁移、黏附、增殖和凋亡。缺乏计算研究阻碍了其进入临床试验的进程。此前,我们利用人工神经网络和细胞自动机范式,并得到体外数据支持,报道了首个关于maspin对肿瘤生长影响的计算模型。本文通过纳入maspin在亚细胞水平上如何影响细胞迁移以及细胞与细胞外基质的相互作用,扩展了先前的计算机模拟模型。使用前馈神经网络来定义每个细胞行为(增殖、静止、凋亡),该行为遵循细胞周期算法以显示微环境对肿瘤生长的影响。此外,该模型着重于计算机模拟实验结果如何能够通过特定的体外数据验证方法进一步证实maspin减少细胞迁移这一事实。从体外和计算机模拟实验收集的数据构成了一个无监督学习问题,可通过使用不同的聚类算法来解决。开发了一种基于密度 的聚类技术,以根据实例之间的连接数量来测量两个数据集之间的相似性。我们提出的聚类算法首先找到每个实例的最近邻,然后根据有多少最近邻共享这两个实例来重新定义实例对之间的相似性。两个实例之间的连接数量定义为它们共有的最近邻数量。结果显示与体外实验数据有显著相似性。这些结果还为maspin的动力学提供了新的见解,并确立其为一种转移抑制基因,以供进一步的分子研究。