Project description:Recent studies have reported high frequencies of somatic mutations in the phosphoinositide-3-kinase catalytic-alpha (PIK3CA) gene in various human solid tumors. More than 75% of those somatic mutations are clustered in the helical (exon 9) and kinase domains (exon 20). The three hot-spot mutations, E542K, E545K, and H1047R, have been proven to elevate the lipid kinase activity of PIK3CA and activate the Akt signaling pathway. The mutational status of PIK3CA in intraductal papillary mucinous neoplasm/carcinoma (IPMN/IPMC) has not been evaluated previously.To evaluate a possible role for PIK3CA in the tumorigenesis of IPMN and IPMC, exons 1, 4, 5, 6, 7, 9, 12, 18, and 20 were analyzed in 36 IPMN/IPMC and two mucinous cystadenoma specimens by direct genomic DNA sequencing.We identified four missense mutations in the nine screened exons of PIK3CA from 36 IPMN/IPMC specimens (11%). One of the four mutations, H1047R, has been previously reported as a hot-spot mutation. The remaining three mutations, T324I, W551G, and S1015F, were novel and somatic.This is the first report of PIK3CA mutation in pancreatic cancer. Our data provide evidence that the oncogenic properties of PIK3CA contribute to the tumorigenesis of IPMN/IPMC.
Project description:Intraductal papillary mucinous neoplasm (IPMN) is the most common pancreatic cyst and a precursor of pancreatic cancer (PDAC). Since PDAC has a devastatingly high mortality rate, the early diagnosis and treatment of any precursor lesion are rational. The safety of the existing guidelines on the clinical management of IPMN has been criticized due to unsatisfactory sensitivity and specificity, showing the need for further markers. Blood obtained from patients with IPMN was therefore subjected to size-based isolation of circulating epithelial cells (CECs). We isolated CECs and evaluated their cytological characteristics. Additionally, we compared Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations in CECs and the primary IPMN tissue, since KRAS mutations are very typical for PDAC. Samples from 27 IPMN patients were analyzed. In 10 (37%) patients, CECs were isolated and showed a hybrid pattern of surface markers involving both epithelial and mesenchymal markers, suggesting a possible EMT process of the cells. Especially, patients with high-grade dysplasia in the main specimen were all CEC-positive. KRAS mutations were also present in CECs but less common than in IPMN tissue. The existence of CEC in IPMN patients offers additional blood-based research possibilities for IMPN biology.
Project description:A 77-year-old man was pointed out thrombocytopenia and polycystic liver and kidney disease following hypertension and diabetes mellitus and duodenitis. He consulted to our hospital for further examination. Computed tomography (CT) showed multiple cysts in the liver and kidney and also showed cystic lesions in the pancreatic tail. The size of the tumor of pancreas was 3 cm × 4 cm. FDG-PET CT showed FDG uptake in the tumor of the pancreatic tail. It has not showed metastasis in the other organs. The examinations suggested that the cause of thrombocytopenia was infection of Helicobacter pylori or idiopathic thrombocytopenic purpura or drugs. We performed distal pancreatectomy for the tumor of pancreas. Histological findings revealed that the tumor of pancreas was invasive intraductal mucinous carcinoma. He had no recurrence for 3 months after operation. In this case, the patient with autosomal-dominant polycystic kidney disease (ADPKD) and multiple liver cysts developed IPMC. We suggest that some genetic interactions may exist between ADPKD and pancreatic carcinogenesis.
Project description:BackgroundGlucose metabolism of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas is unclear. S6 ribosomal protein (S6) phosphorylation is involved not only in controlling cell growth but also in glucose metabolism in cancer. The aim of this study was to investigate the role of S6 phosphorylation and the significance of glucose metabolic changes in IPMN.MethodsRecords of 39 patients who underwent preoperative FDG-PET and curative resection were enrolled in this study. S6 phosphorylation and GLUT1 expression were evaluated immunohistochemically in these patients. The effect of S6 phosphorylation on glucose uptake was examined in cancer cell lines. To examine the change of glucose metabolism in IPMN clinically, the relation between clinical factors including FDG-PET and malignancy of IPMN was investigated.ResultsS6 phosphorylation and GLUT1 expression were significantly higher in carcinoma than in normal cells or adenoma. Cell lines with high level of S6 phosphorylation showed high glucose uptake, and inhibition of S6 phosphorylation reduced glucose uptake. In clinical examination, FDG-PET was the independent factor related to the diagnosis of adenoma or carcinoma (odds ratio = 20.0, 95% confidence interval = 1.837-539.9, P = .012). FDG-PET detected carcinoma with a sensitivity of 81.8%, specificity of 96.4%, and accuracy of 92.3%.ConclusionS6 phosphorylation was associated with glucose uptake and malignancy of IPMN. Moreover, glucose uptake increased in malignant cells of IPMN, and FDG-PET is useful for detecting malignancy of IPMN.
Project description:Intraductal papillary mucinous neoplasm (IPMN) of pancreas has a high risk to develop into invasive cancer or co-occur with malignant lesion. Therefore, it is important to assess its malignant risk by less-invasive approach. Pancreatic juice cell-free DNA (PJD) would be an ideal material in this purpose, but genetic biomarkers for predicting malignant risk from PJD are not yet established. We here performed deep exome sequencing analysis of PJD from 39 IPMN patients with or without malignant lesion. Somatic alterations and copy number alterations (CNAs) detected in PJD were compared with the histologic grade of IPMN to evaluate their potential as a malignancy marker. Somatic mutations of KRAS, GNAS, TP53, and RNF43 were commonly detected in PJD of IPMNs, but no association with the histologic grades of IPMN was found. Instead, mutation burden was positively correlated with the histologic grade (r = 0.427, P = 0.015). We also observed frequent copy number deletions in 17p13 (TP53) and amplifications in 7q21 and 8q24 (MYC) in PJDs. The amplifications in 7q21 and 8q24 were positively correlated with the histologic grade and most prevalent in the cases of invasive carcinoma (P = 0.002 and 7/11; P = 0.011 and 6/11, respectively). We concluded that mutation burden and CNAs detected in PJD may have potential to assess the malignant progression risk of IPMNs.