Gene Rearrangement and Expression of PRKACA and PRKACB Govern Morphobiology of Pancreatobiliary Oncocytic Neoplasms.

Intraductal oncocytic papillary neoplasms (IOPNs) are distinct from intraductal papillary mucinous neoplasms based on characteristic morphologic and genetic features represented by fusion genes involving PRKACA or PRKACB (PRKACA/B). However, pancreatic and biliary tumors with partial oncocytic features are often encountered clinically, and their molecular features are yet to be clarified. This study included 80 intraductal papillary neoplasms: 32 tumors with mature IOPN morphology (typical), 28 with partial or subclonal oncocytic features (atypical), and 20 without oncocytic features (control). We analyzed PRKACA/B fusion genes, including ATP1B1::PRKACA, DNAJB1::PRKACA, and ATP1B1::PRKACB, by reverse-transcription PCR; mRNA expression of fusion genes and nonrearranged PRKACA/B genes by quantitative reverse-transcription PCR; mutations in KRAS, BRAF, and GNAS by targeted sequencing or droplet digital PCR; and the expression of cyclic adenosine monophosphate (cAMP)-dependent protein kinase catalytic subunits α (PRKACA) and ß (PRKACB), phosphorylated cAMP response element-binding protein, and aberrations of p16, p53, SMAD4, STK11, and ß-catenin by immunohistochemistry. PRKACA/B fusion genes were detected in 100% (32/32) of typical, 46% (13/28) of atypical, and 0% (0/20) of control (P < .05). Expression of PRKACA, PRKACB, and phosphorylated cAMP response element-binding protein was upregulated in neoplasms with PRKACA/B fusion genes (P < .05). mRNA expression of the PRKACA/B fusion genes and protein expression of PRKACA or PRKACB tended to be higher in typical than in atypical cases (mRNA, P = .002; protein expression, P = .054). In some atypical neoplasms with mixed subtypes, PRKACA/B fusion genes were superimposed exclusively on oncocytic components. Typical IOPNs harbored fewer KRAS and GNAS mutations than control samples and fewer alterations in p53 and STK11 than atypical samples (P < .05). In conclusion, PRKACA/B fusion genes not only are the characteristic drivers of IOPNs but also play a crucial role in the development of subclonal oncocytic neoplasms. Moreover, oncocytic morphology is strongly associated with upregulation of PRKACA/B, which may provide clues for potential therapeutic options.

Duodenal and pancreatic tissue microbiome profiles of PPI users and non-users.

Factors that influence the pancreas microbiome are not well understood. Regular proton pump inhibitor (PPI) use induces significant alterations in the gut microbiome, including an increase in the abundance of Streptococcus, and may be associated with pancreatic cancer risk. The aim of this study was to examine whether PPI use is associated with pancreatic and duodenal tissue microbiomes. We compared 16S rRNA microbiome profiles of normal pancreatic and duodenal tissue from 103 patients undergoing pancreatic surgery for non-malignant indications, including 34 patients on PPIs, accounting for factors including age, smoking, body mass index and the presence of main pancreatic duct dilation. Histologically normal tissue from the pancreatic head had higher alpha diversity and enrichment of Firmicutes by phylum-level analysis and Streptococcus species compared to normal pancreas body/tail tissues (16.8 % vs 8.8 %, P = .02, and 5.9 % vs 1.4 %, P = .03, respectively). Measures of beta diversity differed significantly between the pancreas and the duodenum, but in subjects with main pancreatic duct dilation, beta diversity of pancreatic head tissue was more similar to normal duodenal tissue than those without pancreatic duct dilation. Duodenal tissue of PPI users had significant enrichment of Firmicute phyla (34.7 % vs. 14.1 %, P = .01) and Streptococcus genera (19.5 % vs. 5.2 %, P = .01) compared to non-users; these differences were not evident in pancreas tissues. By multivariate analysis, PPI use was associated with alpha diversity in the duodenum, but not in the pancreas. However, some differences in pancreas tissue beta diversity were observed between PPI users and non-users. In summary, we find differences in the microbiome profiles of the pancreas head versus the pancreatic body/tail and we find PPI use is associated with alterations in duodenal and pancreatic tissue microbiome profiles.

Reduced expression of phosphorylated ataxia-telangiectasia mutated gene is related to poor prognosis and gemcitabine chemoresistance in pancreatic cancer.

BACKGROUND: Loss of expression of the gene ataxia-telangiectasia mutated (ATM), occurring in patients with multiple primary malignancies, including pancreatic cancer, is associated with poor prognosis. In this study, we investigated the detailed molecular mechanism through which ATM expression affects the prognosis of patients with pancreatic cancer. METHODS: The levels of expression of ATM and phosphorylated ATM in patients with pancreatic cancer who had undergone surgical resection were analyzed using immunohistochemistry staining. RNA sequencing was performed on ATM-knockdown pancreatic-cancer cells to elucidate the mechanism underlying the invlovement of ATM in pancreatic cancer. RESULTS: Immunohistochemical analysis showed that 15.3% and 27.8% of clinical samples had low levels of ATM and phosphorylated ATM, respectively. Low expression of phosphorylated ATM substantially reduced overall and disease-free survival in patients with pancreatic cancer. In the pancreatic cancer cell lines with ATM low expression, resistance to gemcitabine was demonstrated. The RNA sequence demonstrated that ATM knockdown induced the expression of MET and NTN1. In ATM knockdown cells, it was also revealed that the protein expression levels of HIF-1α and antiapoptotic BCL-2/BAD were upregulated. CONCLUSIONS: These findings demonstrate that loss of ATM expression increases tumor development, suppresses apoptosis, and reduces gemcitabine sensitivity. Additionally, loss of phosphorylated ATM is associated with a poor prognosis in patients with pancreatic cancer. Thus, phosphorylated ATM could be a possible target for pancreatic cancer treatment as well as a molecular marker to track patient prognosis.

Salivary gland cancer organoids are valid for preclinical genotype-oriented medical precision trials.

Salivary gland cancers (SGCs) are heterogeneous tumors, and precision oncology represents a promising therapeutic approach; however, its impact on SGCs remains obscure. This study aimed to establish a translational model for testing molecular-targeted therapies by combining patient-derived organoids and genomic analyses of SGCs. We enrolled 29 patients, including 24 with SGCs and 5 with benign tumors. Resected tumors were subjected to organoid and monolayer cultures, as well as whole-exome sequencing. Organoid and monolayer cultures of SGCs were successfully established in 70.8% and 62.5% of cases, respectively. Organoids retained most histopathological and genetic profiles of their original tumors. In contrast, 40% of the monolayer-cultured cells did not harbor somatic mutations of their original tumors. The efficacy of molecular-targeted drugs tested on organoids depended on their oncogenic features. Organoids recapitulated the primary tumors and were useful for testing genotype-oriented molecular targeted therapy, which is valuable for precision medicine in patients with SGCs.

Molecular comparison of concurrent components of high-grade dysplasia, adenocarcinoma, and sarcomatoid carcinoma in a case of sarcomatoid carcinoma of the gallbladder.

Detailed genetic and immunohistochemical features of a sarcomatoid carcinoma of the gallbladder were reported. Studied was a resected gallbladder tumor involving the transverse colon, which was consisted of 3 histopathological neoplastic components, i.e., high-grade dysplasia, adenocarcinoma, and sarcomatoid carcinoma. The targeted amplicon sequencing showed somatic mutations in TP53 (p.S90fs) and ARID1A (c.4993 + 1G > T) in all of the 3 components. Copy numbers of CDKN2A and SMAD4 were decreased in the adenocarcinoma and the sarcomatoid component. Immunohistochemistry showed loss of expression of p53 and ARID1A in all components. p16 expression was lost in the adenocarcinoma and the sarcomatoid component, while SMAD4 expression was lost only in the latter. These results suggest that this sarcomatoid carcinoma may have developed by progression from high-grade dysplasia via adenocarcinoma with sequential accumulation of molecular aberrations involving p53, ARID1A, p16, and SMAD4. This information should serve to understand the molecular mechanism of this very intractable tumor.

Long Non-Coding RNAs Associated with Mitogen-Activated Protein Kinase in Human Pancreatic Cancer.

Long non-coding RNAs (lncRNAs) have emerged as a significant player in various cancers, including pancreatic cancer. However, how lncRNAs are aberrantly expressed in cancers is largely unknown. We hypothesized that lncRNAs would be regulated by signaling pathways and contribute to malignant phenotypes of cancer. In this study, to understand the significance of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), which is a major aberrant signaling pathway in pancreatic cancer, for the expression of lncRNAs, we performed comparative transcriptome analyses between pancreatic cancer cell lines with or without activation of MAPK. We identified 45 lncRNAs presumably associated with MAPK in pancreatic cancer cells; among these, LINC00941 was consistently upregulated by MAPK. The immediate genomic upstream region flanking LINC00941 was identified as a promoter region, the activity of which was found to be preferentially associated with MAPK activity via ETS-1 binding site. LINC00941 promoted cell proliferation in vitro. Moreover, TCGA data analysis indicated that high expression of LINC00941 was associated with poor prognosis of patients with pancreatic cancer. Transcriptomes comparing transcriptions between cells with and without LINC00941 knockdown revealed 3229 differentially expressed genes involved in 44 biological processes, including the glycoprotein biosynthetic process, beta-catenin-TCF complex assembly, and histone modification. These results indicate that MAPK mediates the aberrant expression of lncRNAs. LINC00941 is the lncRNA by MAPK most consistently promoted, and is implicated in the dismal prognosis of pancreatic cancer. MAPK-associated lncRNAs may play pivotal roles in malignant phenotypes of pancreatic cancer, and as such might represent both potentially valid therapeutic targets and diagnostic biomarkers.

A long-term survivor of metachronous liver metastases of pancreatic serous cystic neoplasm associated with von Hippel-Lindau disease.

BACKGROUND: Pancreatic serous cystic neoplasm (SCN) is an uncommon exocrine neoplasm, which is believed to be a benign entity. However, some of these neoplasms may occasionally attain metastatic ability. Von Hippel-Lindau disease (VHL) manifests a dominantly inherited systemic syndrome accompanied by several benign or malignant tumors, including cystic tumors, in various organs. We describe here a long-term survival case who underwent surgical resection for metachronous liver metastases of pancreatic SCN associated with VHL disease. CASE PRESENTATION: A 35-year-old woman with VHL underwent total pancreatectomy and right nephrectomy for pancreatic SCN and renal cell carcinoma, respectively. At the 4th year follow-up examination after the resection, contrast-enhanced computed tomography (CT) and gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) showed arterially hyper-enhanced neoplastic lesions in the segment VI and VIII of the liver. Partial resections of the liver were performed 53 months after the initial surgery. At the 6th month follow-up examination from the second surgery, one and two tumors located in the liver segment III, and VIII, respectively, were detected by contrast-enhanced CT and Gd-EOB-DTPA-enhanced MRI. Anterior segmentectomy and partial resection of the segment III were performed 66 months after the initial surgery and 13 months after the second, respectively. The tumors were pathologically diagnosed as liver metastases of pancreatic SCN synonymous with serous cystadenocarcinoma. She remains disease-free without recurrence 6.5 years after the last operation. CONCLUSIONS: This is the first report of a case of metastatic SCN associated with VHL. Surgical resection might confer a favorable prognosis in patients of pancreatic SCN with liver metastases.

Development of a system combining comprehensive genotyping and organoid cultures for identifying and testing genotype-oriented personalised medicine for pancreatobiliary cancers.

BACKGROUND: Pancreatobiliary cancer is a highly aggressive tumour with a dismal prognosis. Personalised medicine represents a promising and effective therapeutic approach for this intractable disease. In this study, we aimed to establish a system for identifying and testing genotype-oriented targeted drugs for pancreatobiliary cancers by combining exome sequencing and organoid culture of primary tumours. METHODS: Tumour cells isolated from resected tumours were subjected to organoid cultures based on published protocols with modifications. Exome sequencing was performed on the primary tumours. Histopathological and molecular features of the primary tumours were validated in the corresponding organoids. Genotype-oriented candidate targeted drugs were identified from exome sequencing, and their efficacies were tested in the organoids. RESULTS: Organoid cultures succeeded in 30 of 54 (55.6%) cases. Six primary cancers of the biliary tract and gall bladder were subjected to exome sequencing, which revealed a variety of somatic mutations of genes involved in signalling pathways, epigenetic modifiers, genome maintenance and metabolic enzymes. Most of the organoids of these 6 cases showed identical histopathological features and genomic aberrations as those of the primary tumours. Some of the aberrations were candidates for targeted therapies. Integrin-linked kinase (ILK) was one such candidate target, and an ILK inhibitor was confirmed to suppress proliferation of patient-derived organoids. CONCLUSIONS: By combining exome sequencing and organoid culture, our model enabled to identify genotype-oriented targets for personalised medicine and to test efficacies of candidate targeted drugs in the organoids. The current proof-of-concept approach could increase therapeutic opportunities for patients with pancreatobiliary cancers.