Objective·To investigate the spatial epigenetic characteristics of spontaneous colon tumors in Apcmin/+mice.Methods·A spatial assay for transposase-accessible chromatin with high-throughput sequencing(ATAC-seq)technology platform was established using an eight-month-old male Apcmin/+mouse model with spontaneous colon tumors.One tumor from a mouse was harvested and embedded in OCT compound for serial cryosectioning;one tissue section was stained with hematoxylin-eosin(H-E)to observe its histological characteristics,while an adjacent section was processed using spatial ATAC-seq technology to generate spatially resolved DNA libraries,followed by sequencing to obtain spatial chromatin accessibility data.Another tumor from the same mouse was digested into a single-cell suspension,in which viable single cells were sorted by flow cytometry and processed for single-cell RNA sequencing.The results were integrated with spatial chromatin accessibility data to jointly analyze the epigenetic characteristics of the colon tumor microenvironment.Results·A stable spatial ATAC-seq platform was successfully established,dividing the tumor into malignant,non-malignant,and malignant-non-malignant boundary regions.Transcription factors enriched in malignant regions included NK2 homeobox 5(NKX2-5)and transcription factor 3(TCF3).Analysis of transcription factor enrichment in the 3 regions revealed two distinct expression trends:one showing a gradual decrease from malignant to boundary to non-malignant regions,and the other exhibiting high expression in malignant and boundary regions but low expression in non-malignant regions.Gene analysis across regions revealed significant upregulation of hypoxia response,transforming growth factor(TGF),and Kirsten rat sarcoma viral oncogene homolog(KRAS)signaling pathways in malignant regions,with cell cycle-related functions markedly enhanced.Analysis of cell-cell interactions in the tumor microenvironment revealed significant differences in interaction strength:strong interactions within non-malignant regions,moderate interactions between boundary and non-malignant regions,and weak interactions between malignant and boundary regions as well as between malignant and non-malignant regions.Conclusion·Colon tumors in Apcmin/+mice exhibit high spatial heterogeneity;malignant regions were enriched with transcription factors including TCF3,and cell interactions between malignant regions and boundary/non-malignant regions were relatively weak.

Objective·To investigate the spatial epigenetic characteristics of spontaneous colon tumors in Apcmin/+mice.Methods·A spatial assay for transposase-accessible chromatin with high-throughput sequencing(ATAC-seq)technology platform was established using an eight-month-old male Apcmin/+mouse model with spontaneous colon tumors.One tumor from a mouse was harvested and embedded in OCT compound for serial cryosectioning;one tissue section was stained with hematoxylin-eosin(H-E)to observe its histological characteristics,while an adjacent section was processed using spatial ATAC-seq technology to generate spatially resolved DNA libraries,followed by sequencing to obtain spatial chromatin accessibility data.Another tumor from the same mouse was digested into a single-cell suspension,in which viable single cells were sorted by flow cytometry and processed for single-cell RNA sequencing.The results were integrated with spatial chromatin accessibility data to jointly analyze the epigenetic characteristics of the colon tumor microenvironment.Results·A stable spatial ATAC-seq platform was successfully established,dividing the tumor into malignant,non-malignant,and malignant-non-malignant boundary regions.Transcription factors enriched in malignant regions included NK2 homeobox 5(NKX2-5)and transcription factor 3(TCF3).Analysis of transcription factor enrichment in the 3 regions revealed two distinct expression trends:one showing a gradual decrease from malignant to boundary to non-malignant regions,and the other exhibiting high expression in malignant and boundary regions but low expression in non-malignant regions.Gene analysis across regions revealed significant upregulation of hypoxia response,transforming growth factor(TGF),and Kirsten rat sarcoma viral oncogene homolog(KRAS)signaling pathways in malignant regions,with cell cycle-related functions markedly enhanced.Analysis of cell-cell interactions in the tumor microenvironment revealed significant differences in interaction strength:strong interactions within non-malignant regions,moderate interactions between boundary and non-malignant regions,and weak interactions between malignant and boundary regions as well as between malignant and non-malignant regions.Conclusion·Colon tumors in Apcmin/+mice exhibit high spatial heterogeneity;malignant regions were enriched with transcription factors including TCF3,and cell interactions between malignant regions and boundary/non-malignant regions were relatively weak.

Objective: To establish a TaqMan-MGB probe-based real-time fluorescence RT-PCR assay for avian influenza H5N6 virus used in rapid diagnosis for suspected cases and surveillance for outer environment of live poultry markets. Methods: Based on the conservative sequences of avian influenza H5N6 virus for HA and NA gene published on GenBank, specific primers and TaqMan-MGB probes were designed to develop and optimize for the dual real-time RT-PCR assay. Specificity, sensitivity, repeatability and comparison tests were carried out. Results: This dual real-time RT-PCR detection can be completed within 80 minutes. There was no cross-reaction with other subtypes of influenza virus and common respiratory pathogens. The minimum detection limit could be up to 10 copies/reaction. The correlation coefficient of standard curve for the gene of H5 and N6 were 0.999 and 0.993, and the coefficients of variation for cycle threshold were range from 0.151%-0.549%and 0.213%-0.575%, respectively. The positive and negative coincidence rates of the validation test were 100%. Conclusions This TaqMan-MGB probe-based dual real-time RT-PCR for avian influenza H5N6 virus was rapid, specific and sensitive. It will have a good use in early emergency detection of suspected cases and continuous monitoring of external environment in live poultry trade market.