Identification of histology-correlated intra-tumor genomic heterogeneity through stimulated Raman scattering micro-dissection sequencing. Homo sapiens

Morphologic and genetic alterations play crucial roles in tumorigenesis, and lay the foundation of diagnosis and cancer research. However, preservation of morphology with staining compromises the genetic materials. Here we propose SMD-Seq, a new approach to achieve consecutive label-free histological images construction and in situ laser micro-dissection of cancer samples for location-specific transcriptome and genome analysis. We applied SMD-Seq to unstained cryosections of human oral squamous cell carcinoma (OSCC) samples. The high quality and purity of genetic materials enabled the discovery of inter- and intra-tumor heterogeneities in both morphology and genetics. The correlative morphologic and molecular analysis of SMD-Seq is capable of dissecting the genetic variation and its effect on gene expression under shape, and provides complementary insights in cancer study.形态学与遗传学改变在肿瘤发生发展中发挥关键作用，同时为肿瘤诊断及癌症研究奠定重要基础。然而，通过染色实现形态学保存的传统方法会损害遗传物质的完整性。本研究提出SMD-Seq技术，该技术可实现无标记连续组织学图像构建，并可对癌症样本开展原位激光显微切割，进而实现位置特异性转录组与基因组分析。我们将SMD-Seq应用于人口腔鳞状细胞癌（oral squamous cell carcinoma, OSCC）样本的未染色冰冻切片，所获得的遗传物质具备高纯度与高质量，借此得以揭示肿瘤在形态学与遗传学层面的瘤间异质性与瘤内异质性。SMD-Seq所开展的形态学与分子关联分析，能够解析遗传变异及其对基因表达的形态学关联影响，可为癌症研究提供互补性的研究视角。