Project description:Cancers predominantly arise from adult stem cells accumulating somatic driver mutations, but how genetic predisposition affects the penetrance of mutations in tumor initiation is not well understood. Here, we have analyzed gene expression in tumor-prone ApcMin/+ mice on highly variant C57BL/6J and PWD/Ph genetic backgrounds. We show that activation of beta-Catenin-driven and stem cell-specific gene expression in the presence of ApcMin or following APC loss is high in B6 mouse intestines, but remains moderate in intestines carrying PWD/Ph chromosome 5, suggesting that PWD/Ph variants restrict adenoma initiation by controlling stem cell homeostasis. Gene expression of modifier candidates and DNA methylation on chromosome 5 are predominantly cis-controlled and largely reflect the parental patterns, providing a genetic basis for inheritance of tumor susceptibility.
Project description:Cancers predominantly arise from adult stem cells accumulating somatic driver mutations, but how genetic predisposition affects the penetrance of mutations in tumor initiation is not well understood. Here, we have analyzed gene expression in tumor-prone ApcMin/+ mice on highly variant C57BL/6J and PWD/Ph genetic backgrounds. We show that activation of beta-Catenin-driven and stem cell-specific gene expression in the presence of ApcMin or following APC loss is high in B6 mouse intestines, but remains moderate in intestines carrying PWD/Ph chromosome 5, suggesting that PWD/Ph variants restrict adenoma initiation by controlling stem cell homeostasis. Gene expression of modifier candidates and DNA methylation on chromosome 5 are predominantly cis-controlled and largely reflect the parental patterns, providing a genetic basis for inheritance of tumor susceptibility.
Project description:Methylation modifications play pertinent roles in regulating gene expression and various biological processes. The silencing of the demethylated modifier TET1 can affect the expressions of key oncogenes or tumor suppressor genes, thus contributing to tumor formation. Nonetheless, how TET1 affects the progression of cervical cancer is yet to be elucidated. In this study, we found that the expression of TET1 was significantly downregulated in cervical cancer tissues. Functionally, TET1 knockdown in cervical cancer cells can promote cell proliferation, migration, invasion, cervical xenograft tumor formation and EMT. On the contrary, its overexpression can reverse the aforementioned processes. Moreover, the autophagy level of cervical cancer cells can be enhanced after TET1 knockdown. Mechanistically, methylated DNA immunoprecipitation (MeDIP)-sequencing and MeDIP quantitative real-time PCR revealed that TET1 mediates the methylation of autophagy promoter regions. These findings suggest that TET1 affects the malignant biological behavior of cervical cancer cells by altering the methylation levels of autophagy genes NKRF and HIST1H2AK, but the specific mechanism needs to be investigated further.
Project description:we used methylated DNA immunoprecipitation sequencing (MeDIP-Seq) to detect DNA methylation levels and lncRNA-seq to detect lncRNA expression levels in 3 lung cancer samples and 3 matched normal samples. Then 255 differentially methylated genes (DMGs) and 246 differentially expressed lncRNAs (DELs) were identified. Finally, LINC01354 was founded to be differentially methylated and predictive of transcription. Besides, the prognostic value of differential methylation related DELs was analyzed.
Project description:Three separate experiments were carried out using MeDIP-seq and cfMeDIP-seq for methylome analysis. For the first experiment, different starting amounts of HCT116 cell line DNA, sheared to mimic cell-free DNA, were analyzed using MeDIP-seq and cfMeDIP-seq. In the second experiment the limit of detection of cfMeDIP-seq was tested using varying dilutions of colorectal cancer cell line DNA (HCT116) with multiple myeloma cell line DNA (MM1.S). For both cell line DNA samples, the DNA was sheared to mimic cell-free DNA. In the final experiment, we tested the enrichment of human ctDNA using cfMeDIP-seq performed on plasma collected from patient-derived xenografts (PDXs) generated in mice from two colorectal cancer patients.