The
gene is mutated in over half of all cancers, reflecting its critical role as a tumor suppressor. Although p53 is a transcriptional activator that induces myriad target genes, those p53-inducible ...genes most critical for tumor suppression remain elusive. Here, we leveraged p53 ChIP-seq (chromatin immunoprecipitation ChIP combined with high-throughput sequencing) and RNA-seq (RNA sequencing) data sets to identify new p53 target genes, focusing on the noncoding genome. We identify
, a noncoding RNA (ncRNA) constituent of paraspeckles, as a p53 target gene broadly induced by mouse and human p53 in different cell types and by diverse stress signals. Using fibroblasts derived from
mice, we examined the functional role of
in the p53 pathway. We found that
is dispensable for cell cycle arrest and apoptosis in response to genotoxic stress. In sharp contrast,
plays a crucial role in suppressing transformation in response to oncogenic signals.
deficiency enhances transformation in oncogene-expressing fibroblasts and promotes the development of premalignant pancreatic intraepithelial neoplasias (PanINs) and cystic lesions in Kras
-expressing mice.
loss provokes global changes in gene expression, suggesting a mechanism by which its deficiency promotes neoplasia. Collectively, these findings identify
as a p53-regulated large intergenic ncRNA (lincRNA) with a key role in suppressing transformation and cancer initiation, providing fundamental new insight into p53-mediated tumor suppression.
Pancreatic cancer Kamisawa, Terumi, Dr; Wood, Laura D, MD; Itoi, Takao, MD ...
The Lancet (British edition),
07/2016, Volume:
388, Issue:
10039
Journal Article
Peer reviewed
Summary Pancreatic cancer is a highly lethal disease, for which mortality closely parallels incidence. Most patients with pancreatic cancer remain asymptomatic until the disease reaches an advanced ...stage. There is no standard programme for screening patients at high risk of pancreatic cancer (eg, those with a family history of pancreatic cancer and chronic pancreatitis). Most pancreatic cancers arise from microscopic non-invasive epithelial proliferations within the pancreatic ducts, referred to as pancreatic intraepithelial neoplasias. There are four major driver genes for pancreatic cancer: KRAS, CDKN2A, TP53 , and SMAD4. KRAS mutation and alterations in CDKN2A are early events in pancreatic tumorigenesis. Endoscopic ultrasonography and endoscopic ultrasonography-guided fine-needle aspiration offer high diagnostic ability for pancreatic cancer. Surgical resection is regarded as the only potentially curative treatment, and adjuvant chemotherapy with gemcitabine or S-1, an oral fluoropyrimidine derivative, is given after surgery. FOLFIRINOX (fluorouracil, folinic acid leucovorin, irinotecan, and oxaliplatin) and gemcitabine plus nanoparticle albumin-bound paclitaxel (nab-paclitaxel) are the treatments of choice for patients who are not surgical candidates but have good performance status.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Pancreatic ductal adenocarcinoma (PDAC) is a clinically challenging cancer, due to both its late stage at diagnosis and its resistance to chemotherapy. However, recent advances in our understanding ...of the biology of PDAC have revealed new opportunities for early detection and targeted therapy of PDAC. In this review, we discuss the pathogenesis of PDAC, including molecular alterations in tumor cells, cellular alterations in the tumor microenvironment, and population-level risk factors. We review the current status of surveillance and early detection of PDAC, including populations at high risk and screening approaches. We outline the diagnostic approach to PDAC and highlight key treatment considerations, including how therapeutic approaches change with disease stage and targetable subtypes of PDAC. Recent years have seen significant improvements in our approaches to detect and treat PDAC, but large-scale, coordinated efforts will be needed to maximize the clinical impact for patients and improve overall survival.
Most patients diagnosed with resected pancreatic adenocarcinoma (PDAC) survive less than 5 years, but a minor subset survives longer. Here, we dissect the role of the tumor microbiota and the immune ...system in influencing long-term survival. Using 16S rRNA gene sequencing, we analyzed the tumor microbiome composition in PDAC patients with short-term survival (STS) and long-term survival (LTS). We found higher alpha-diversity in the tumor microbiome of LTS patients and identified an intra-tumoral microbiome signature (Pseudoxanthomonas-Streptomyces-Saccharopolyspora-Bacillus clausii) highly predictive of long-term survivorship in both discovery and validation cohorts. Through human-into-mice fecal microbiota transplantation (FMT) experiments from STS, LTS, or control donors, we were able to differentially modulate the tumor microbiome and affect tumor growth as well as tumor immune infiltration. Our study demonstrates that PDAC microbiome composition, which cross-talks to the gut microbiome, influences the host immune response and natural history of the disease.
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•PDAC long-term survivors display high tumor microbial diversity and immunoactivation•A PDAC tumoral microbiome signature predicts PDAC long-term survival•The gut microbiome modulates the PDAC tumor microbiome landscape•Fecal microbial transplants can modulate tumors immunosuppression and growth
The distinct tumor microbiome from pancreatic cancer long-term survivors can be used to predict PDAC survival in humans, and transfer of long-term survivor gut microbiomes can alter the tumor microbiome and tumor growth in mouse models.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the previous decade, comprehensive genomic analyses have yielded important insights about the genetic alterations that underlie pancreatic tumorigenesis. Whole-exome and whole-genome sequencing of ...pancreatic ductal adenocarcinomas have confirmed the critical driver genes altered in the majority of pancreatic cancers, as well as identified numerous less frequently altered driver genes, and have delineated cancer subgroups with unique biological and clinical features. It is now appreciated that pancreatic susceptibility gene alterations are often identified in patients with pancreatic cancer without family histories suggestive of a familial cancer syndrome, prompting recent efforts to expand gene testing to all patients with pancreatic cancer. Studies of pancreatic cancer precursor lesions have begun to elucidate the evolutionary history of pancreatic tumorigenesis and to help us understand the utility of biomarkers for early detection and targets to develop new therapeutic strategies. In this review, we discuss the results of comprehensive genomic characterization of pancreatic ductal adenocarcinoma and its precursor lesions, and we highlight translational applications in early detection and therapy.
High-grade serous ovarian carcinoma (HGSOC) is the most frequent type of ovarian cancer and has a poor outcome. It has been proposed that fallopian tube cancers may be precursors of HGSOC but ...evolutionary evidence for this hypothesis has been limited. Here, we perform whole-exome sequence and copy number analyses of laser capture microdissected fallopian tube lesions (p53 signatures, serous tubal intraepithelial carcinomas (STICs), and fallopian tube carcinomas), ovarian cancers, and metastases from nine patients. The majority of tumor-specific alterations in ovarian cancers were present in STICs, including those affecting TP53, BRCA1, BRCA2 or PTEN. Evolutionary analyses reveal that p53 signatures and STICs are precursors of ovarian carcinoma and identify a window of 7 years between development of a STIC and initiation of ovarian carcinoma, with metastases following rapidly thereafter. Our results provide insights into the etiology of ovarian cancer and have implications for prevention, early detection and therapeutic intervention of this disease.
The p53 transcription factor is a critical barrier to pancreatic cancer progression. To unravel mechanisms of p53-mediated tumor suppression, which have remained elusive, we analyzed pancreatic ...cancer development in mice expressing p53 transcriptional activation domain (TAD) mutants. Surprisingly, the p5353,54 TAD2 mutant behaves as a “super-tumor suppressor,” with an enhanced capacity to both suppress pancreatic cancer and transactivate select p53 target genes, including Ptpn14. Ptpn14 encodes a negative regulator of the Yap oncoprotein and is necessary and sufficient for pancreatic cancer suppression, like p53. We show that p53 deficiency promotes Yap signaling and that PTPN14 and TP53 mutations are mutually exclusive in human cancers. These studies uncover a p53-Ptpn14-Yap pathway that is integral to p53-mediated tumor suppression.
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•The p5353,54 TAD2 mutant is a super-tumor suppressor in pancreatic cancer•p5353,54 hyperactivates Ptpn14, a p53 target gene involved in tumor suppression•p53 negatively regulates Yap through Ptpn14 activation•p53-Ptpn14-Yap is a key tumor suppressive axis in mice and humans
Mello et al. find that a p53 mutant harboring mutations in the second transcriptional activation domain has enhanced tumor suppression capacities due to hyperactivation of the p53 target gene Ptpn14. Ptpn14 suppresses Yap activity and is required for p53 tumor suppressor activity in pancreatic cancer.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
For the majority of patients with pancreas cancer, the high metastatic proclivity is life limiting. Some patients, however, present with and succumb to locally destructive disease. A molecular ...understanding of these distinct disease manifestations can critically inform patient management. Using genetically engineered mouse models, we show that heterozygous mutation of Dpc4/Smad4 attenuates the metastatic potential of KrasG12D/+;Trp53R172H/+ pancreatic ductal adenocarcinomas while increasing their proliferation. Subsequent loss of heterozygosity of Dpc4 restores metastatic competency while further unleashing proliferation, creating a highly lethal combination. Expression levels of Runx3 respond to and combine with Dpc4 status to coordinately regulate the balance between cancer cell division and dissemination. Thus, Runx3 serves as both a tumor suppressor and promoter in slowing proliferation while orchestrating a metastatic program to stimulate cell migration, invasion, and secretion of proteins that favor distant colonization. These findings suggest a model to anticipate likely disease behaviors in patients and tailor treatment strategies accordingly.
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•DPC4 dosage regulates RUNX3 levels in a biphasic manner•RUNX3 controls the balance between local growth and dissemination in PDA•RUNX3 functions as both tumor suppressor and tumor promoter in PDA•DPC4 and RUNX3 levels can jointly inform clinical decision making
RUNX3 regulates the balance between proliferation and dissemination of pancreas cancer cells in response to gene dosage of DPC4/SMAD4. Evaluating the levels of DPC4 and RUNX3 can help predict patterns of relapse and response to therapies in patients, informing clinical disease management.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease with a 5-year survival rate of approximately 9%. An improved understanding of PDAC initiation and progression is paramount for discovering ...strategies to better detect and combat this disease. Although transcriptomic analyses have uncovered distinct molecular subtypes of human PDAC, the factors that influence subtype development remain unclear. Here, we interrogate the impact of cell of origin and different
alleles on tumor evolution, using a panel of tractable genetically engineered mouse models. Oncogenic KRAS expression, coupled with
deletion or point mutation, drives PDAC from both acinar and ductal cells. Gene-expression analysis reveals further that ductal cell-derived and acinar cell-derived tumor signatures are enriched in basal-like and classical subtypes of human PDAC, respectively. These findings highlight cell of origin as one factor that influences PDAC molecular subtypes and provide insight into the fundamental impact that the very earliest events in carcinogenesis can have on cancer evolution. SIGNIFICANCE: Although human PDAC has been classified into different molecular subtypes, the etiology of these distinct subtypes remains unclear. Using mouse genetics, we reveal that cell of origin is an important determinant of PDAC molecular subtype. Deciphering the biology underlying pancreatic cancer subtypes may reveal meaningful distinctions that could improve clinical intervention.
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