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Tumor Discovery                                                       AI uncovers tumor spatial organization




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            Figure 2. The spatial clustering results of seven compared methods on human DLPFC data; (A) the average adjusted Rand index (ARI) values in seven
            methods for twelve samples; (B) the ground truth of sample 15,1673 of this spatial transcriptomics (ST) data; (C) the spatial domain identification results
            of the proposed method VGAE_SGC; and (D) the spatial clustering results of six benchmarking methods for comparison.
            Abbreviation: DLPFC: Dorsolateral pre-frontal cortex.

            morphotypes: DCIS/LCIS, IDC, tumor edge, and healthy   HLA-B for cluster 11. This analysis suggests disparate gene
            areas (Figure 3A). All seven approaches yielded ARI values   profiles for the two groups, which are indicative of distinct
            exceeding 0.50, with VGAE_SGC achieving the highest   cell types. To elucidate the biological functions associated
            ARI of 0.603 (Figure 3B). Figure 3C illustrates the spatial   with these clusters, we conducted a gene set enrichment
            clustering  outcomes  of  the  top  three  methods.  Notably,   analysis of these differentially expressed genes. The enriched
            in the case of VGAE_SGC, several clusters (0, 10, 1, 13,   pathways for these clusters predominantly pertained to
            7, and 14) were closely aligned with the ground truth.   antigen processing and presentation (Figure 3E).
            These findings underscore the efficacy of VGAE_SGC in
            identifying cell subpopulations and effectively detecting   3.3. Partitioning tumor regions for the single-cell-
            the tumor microenvironment.                        resolution human breast cancer data

              We performed a comprehensive downstream analysis   Finally, we validated our proposed spatial clustering
            of the spatial clustering results obtained from VGAE_  framework, VGAE_SGC, using an alternative single-cell-
            SGC.  Specifically,  the  IDC_5  region  was  divided  into   resolution ST dataset. This dataset was produced utilizing
            two distinct clusters, denoted as clusters 2 and 11, within   the advanced 10x Xenium technology and pertains to
            VGAE_SGC. We, further, scrutinized the rationale behind   breast cancer tissue, as shown in Figure 4A. The initial ST
            the segmentation of the cell types. The differential gene   dataset boasts a high resolution, comprising 164,079 spots
            expression profiles for clusters 2 and 11 are depicted in   and 313 genes. To alleviate the computational demands,
            Figure 3D, revealing COX6C for cluster 2, and ADIRF and   we segmented this primary dataset into a cropped subset,


            Volume 3 Issue 1 (2024)                         6                          https://doi.org/10.36922/td.2049
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