Pancreatic cancer is the eighth most common cancer and has an overall 5-year survival rate lower than 10%. Because of their ability to regulate gene expression, microRNAs can act as oncogenes or tumor-suppressor genes and so have garnered interest as possible prognostic and therapeutic markers during the last decade. However, the prognostic value of microRNA expression in pancreatic cancer has not been thoroughly investigated. We measured the levels of miR-155, miR-203, miR-210, miR-216, miR-217 and miR-222 by quantitative RT-PCR in a cohort of 56 microdissected pancreatic ductal adenocarcinomas (PDAC). These microRNAs were chosen as they had previously been shown to be differentially expressed in pancreatic tumors compared to normal tissues. The possible association of microRNA expression and patients' survival was examined using multivariate Cox's regression hazard analyses. Interestingly, significant correlations between elevated microRNA expression and overall survival were observed for miR-155 (RR 5 2.50; p 5 0.005), miR-203 (RR 5 2.21; p 5 0.017), miR-210 (RR 5 2.48; p 5 0.005) and miR-222 (RR 5 2.05; p 5 0.035). Furthermore, tumors from patients demonstrating elevated expression levels of all 4 microRNAs possessed a 6.2-fold increased risk of tumor-related death compared to patients whose tumors showed a lower expression of these microRNAs. This study provides the first evidence for an oncogenic activity of miR-155, miR-203, miR-210 and miR-222 in the development of pancreatic cancer as has been reported for other tumor types. Furthermore, the putative target genes for these microRNAs suggest a complex signaling network that can affect PDAC tumorigenesis and tumor progression.Because of its poor prognosis, pancreatic cancer is one of the leading causes of cancer-related death, despite its relative low incidence with 9 cases per 100,000 people. 1 The poor prognosis of patients is a result of the late clinical presentation and the high metastatic potential. Three-fourths of pancreatic carcinomas are ductal adenocarcinomas (PDAC). 2 There are molecular prognostic markers known for pancreatic cancers. For example, higher levels of protein expression of VEGF or EGFR have been shown to associate with poorer survival rates. 3 Besides non-physiological KRAS activation, which is mutated in about 95% of all pancreatic carcinomas, 4 inactivation of known tumor-suppressor genes such as p53 or SMAD4 (deleted in 75% or 55% of all PDACs, respectively) have been demonstrated. 5,6 MicroRNAs are small, non-coding RNAs of endogenous origin, which mainly function as negative regulators of gene expression. The association of altered microRNA expression with cancerogenesis as well as tumor progression is well established. [7][8][9] There is a growing number of microRNAs, which are classified as oncogenes or tumor-suppressor genes. 10 For instance, miR-17-92-cluster has gained interest by being regulated via c-myc and its ability to accelerate tumor formation. 11,12 Also, let-7 expression was described to correlate with a poo...
Piwi proteins and their interaction with piRNAs have rapidly emerged as important contributors to gene regulation, indicating their crucial function in germline and stem cell development. However, data on the Hiwi 1 (Hiwi) gene, one of the four human Piwi homologues, are still scarce. Therefore, we investigated the Hiwi mRNA expression in microdissected PDAC tissues from patients with ductal adenocarcinoma of the pancreas (PDAC) by quantitative real-time PCR and the protein expression by immunohistochemistry. Elevated levels of Hiwi mRNA transcripts were measured in 40 out of 56 tissues and a positive immunostaining of Hiwi was detected in tumours of 21 out of 78 patients. There was no general impact of elevated Hiwi mRNA transcript levels or protein expression on survival, as tested by multivariate Cox regression and Kaplan -Meier analysis. However, men showed a significantly increased risk for tumour-related death in case of down-or upregulated expression of Hiwi mRNA (relative risk (RR) ¼ 2.78; P ¼ 0.034). In summary, we report the first analysis of Hiwi expression in PDAC and its impact on prognosis. We suggest that alterations in mRNA expression of Hiwi can increase the risk of tumour-related death in male PDAC patients.
Summary Background 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov , NCT03471494 . Findings Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding National Institute for Health Research Global Health Research Unit.
The p53 tumor suppressor pathway is central both in reducing cancer frequency in vertebrates and in mediating the response of commonly used cancer therapies. This article aims to summarize and discuss a large body of evidence suggesting that the p53 pathway harbors functional inherited single-nucleotide polymorphisms (SNPs) that affect p53 signaling in cells, resulting in differences in cancer risk and clinical outcome in humans. The insights gained through these studies into how the functional p53 pathway SNPs could help in the tailoring of cancer therapies to the individual are discussed. Moreover, recent work is discussed that suggests that many more functional p53 pathway SNPs are yet to be fully characterized and that a thorough analysis of the functional human genetics of this important tumor suppressor pathway is required.
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