Dynamic chromatin structure acts as the regulator of transcription program in crucial processes including cancer and cell development, but a unified framework for characterizing chromatin structural evolution remains to be established. Here, we performed graph inferences on Hi-C data sets and derived the chromatin contact networks. We discovered significant decreases in information transmission efficiencies in chromatin of colorectal cancer (CRC) and T-cell acute lymphoblastic leukemia (T-ALL) compared to corresponding normal controls through graph statistics. Using network embedding in the Poincaré disk, the hierarchy depths of chromatin from CRC and T-ALL patients were found to be significantly shallower compared to their normal controls. A reverse trend of change in chromatin structure was observed during early embryo development. We found tissue-specific conservation of hierarchy order in chromatin contact networks. Our findings reveal the top-down hierarchy of chromatin organization, which is significantly attenuated in cancer.

中文翻译：

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网络层次结构的表征反映了基因组组织中细胞状态的特异性

动态染色质结构在癌症和细胞发育等关键过程中充当转录程序的调节者，但表征染色质结构进化的统一框架仍有待建立。在这里，我们对 Hi-C 数据集进行了图推理并得出了染色质接触网络。通过图形统计，我们发现结直肠癌（CRC）和T细胞急性淋巴细胞白血病（T-ALL）的染色质信息传递效率与相应的正常对照相比显着降低。使用庞加莱圆盘中的网络嵌入，发现 CRC 和 T-ALL 患者的染色质层次深度比正常对照明显浅。在早期胚胎发育过程中观察到染色质结构变化的相反趋势。我们发现染色质接触网络中组织特异性的层次顺序保守。我们的研究结果揭示了染色质组织的自上而下的层次结构，这种层次结构在癌症中显着减弱。