Project description:Pancreatic cancer is one of the deadliest human malignancies, with a survival rate less than 10%. Traditional modes of therapy have proven ineffective in the treatment of pancreatic cancer, highlighting the need to further understand the basic biology of the disease in order to identify new treatment modalities. Previously, our group showed that the epigenetic regulator Bmi1 is required for the initiation of pancreatic cancer in mice. In murine models of PDAC, mice lacking pancreatic Bmi1 expression do not develop precancerous lesions, despite oncogene expression. In this work, we sought to determine the role of Bmi1 in later stages of pancreatic tumor development. Using a CRISPR/Cas9 strategy, we deleted Bmi1 in primary human pancreatic caner cells and created clonal lines. When used in a subcutaenous tumor growth assay, those cells lacking BMI1 expression formed tumors that grew significantly smaller than controls. To query the mechanism of BMI1 action in pancreatic cancer growth, we used RNA sequencing to compare those pancreatic cancer cells with and without BMI1 expressed. This revealed that Bmi1 controls the gene expression of glycolysis and cell proliferation pathways, likely the reason for its requirement in pancreatic tumor growth. Overall, we found that Bmi1 is required in pancreatic tumor progression, and that it controls gene expression in both glycolysis and cell proliferation.
Project description:This study aimed to understand the role that B lymphoma Mo-MLV insertion region 1 homolog (Bmi-1) plays in non-small cell lung cancer (NSCLC) progression. According to fold-change screening between Bmi-1-silencing A549 and the control cells A549, both up-regulated and down-regulated genes were shown.
Project description:Pancreatic cancer is among the deadliest cancers that affects almost 54,000 patients in United States alone, with 90% of them succumbing to the disease. Lack of early detection is considered to be the foremost reason for such dismal survival rates. Our study shows that resident gut microbiota is altered at the early stages of tumorigenesis much before development of observable tumors in a spontaneous, genetically engineered mouse model for pancreatic cancer. In the current study, we analyzed the microbiome of in a genetic mouse model for PDAC (KRASG12DTP53R172HPdxCre or KPC) and age-matched controls using WGS at very early time points of tumorigenesis. During these time points, the KPC mice do not show any detectable tumors in their pancreas. Our results show that at these early time points, the histological changes in the pancreas correspond to a significant change in certain gut microbial population. Our predictive metabolomic analysis on the identified bacterial species reveal that the primary microbial metabolites involved in progression and development of PDAC tumors are involved in polyamine metabolism.
Project description:Post-translational modifications of malignant transformation and tumor maintenance in pancreatic ductal adenocarcinoma (PDAC) in the context of KRAS signaling remains largely unexplored. Here, we used the KPC mouse model to examine the effect of palmitoylation on pancreatic cancer progression. ZDHHC20, upregulated by KRAS, is abnormally overexpressed and associated with poor prognosis in patients with pancreatic cancer. Dysregulation of ZDHHC20 promotes pancreatic cancer progression in a palmitoylation-dependent manner. ZDHHC20 inhibits lysosomal localization and degradation of YTHDF3 through S-palmitoylation of Cys474, which can result in abnormal accumulation of the oncogenic product MYC and thereby promote the malignant phenotypes of cancer cells. Further, we designed a biologically active YTHDF3-derived peptide to competitively inhibit YTHDF3 palmitoylation mediated by ZDHHC20, which in turn downregulated MYC expression and inhibited the progression of KRAS mutant pancreatic cancer. Thus, these findings highlight the therapeutic potential of targeting the ZDHHC20-YTHDF3-MYC signaling axis in pancreatic cancer.