Long Non-coding RNA LINC01420 Contributes to Pancreatic Cancer Progression Through Targeting KRAS Proto-oncogene.
- 作者列表："Zhai H","Zhang X","Sun X","Zhang D","Ma S
BACKGROUND:Long non-coding RNAs (lncRNAs) have been increasingly uncovered to participate in multiple human cancers, including pancreatic cancer (PC). However, the underlying mechanisms of most of the lncRNAs have not been fully understood yet. AIMS:In this study, we probed the role and latent mechanism of LINC01420 in PC. METHODS:Several online tools were applied. Gene expression was evaluated by qRT-PCR or Western blot. Both in vitro and in vivo assays were conducted to probe LINC01420 function in PC. ChIP, RIP, and luciferase reporter assays were performed to determine relationships between genes. RESULTS:The bioinformatics analyses revealed LINC01420 was highly expressed in PC tissues. Besides, LINC01420 was pronouncedly upregulated in PC cell lines and its depletion controlled PC cell proliferation and EMT in vitro and hindered tumor growth in vivo. Importantly, KRAS was proved to mediate LINC01420-facilitated PC cell proliferation. Further, we explained that KRAS transcription was regulated by MYC, while LINC01420 enhanced the binding of MYC to KRAS promoter in the nucleus of PC cells. Intriguingly, LINC01420 boosted MYC expression in the cytoplasm of PC cells by sponging miR-494-3p. CONCLUSION:This study illustrated that LINC01420 accelerates PC progression through releasing miR-494-3p-silenced MYC in cytoplasm and upregulating MYC-activated KRAS in nucleus, unveiling LINC01420 as a latent therapeutic strategy for PC patients.
背景: 长链非编码rna (lncRNAs) 越来越多地被发现参与多种人类癌症，包括胰腺癌 (PC)。然而，大多数lncRNAs的潜在机制尚未完全理解。 目的: 探讨LINC01420在PC中的作用及潜在机制。 方法: 应用几种在线工具。通过qRT-PCR或蛋白质印迹评价基因表达。进行体外和体内试验以探测LINC01420在PC中的功能。进行ChIP、RIP和荧光素酶报告分析以确定基因之间的关系。 结果: 生物信息学分析显示LINC01420在PC组织中高表达。此外，LINC01420在PC细胞系中明显上调，其耗竭在体外控制PC细胞增殖和EMT，并在体内阻碍肿瘤生长。重要的是，KRAS被证明介导LINC01420-facilitated PC细胞增殖。此外，我们解释了KRAS转录受MYC调控，而LINC01420增强了MYC与PC细胞核中KRAS启动子的结合。有趣的是，LINC01420通过海绵miR-494-3p促进了PC细胞细胞质中的MYC表达。 结论: 本研究表明LINC01420通过释放细胞质中miR-494-3p-silenced的MYC和上调细胞核中MYC激活的KRAS来加速PC进展，揭示了LINC01420作为PC患者潜在的治疗策略。
METHODS:OBJECTIVE:The aim of this study was to investigate the key molecular alterations in small primary pancreatic neuroendocrine tumors (PanNETs) associated with the development of liver metastases. BACKGROUND:Well-differentiated PanNETs with small size are typically indolent; however, a limited subset metastasize to the liver. METHODS:A total of 87 small primary PanNETs (<3 cm), including 32 metastatic cases and 55 nonmetastatic cases after a 5-year follow-up, were immunolabeled for DAXX/ATRX and analyzed for alternative lengthening of telomeres (ALT) by Fluorescence In Situ Hybridization. A subset of these cases, 24 that metastasized and 24 that did not metastasize, were assessed by targeted next-generation sequencing and whole-genome copy number variation. RESULTS:In the entire cohort, high Ki-67 (OR 1.369; 95% CI 1.121-1.673; P = 0.002), N-stage (OR 4.568; 95% CI 1.458-14.312; P = 0.009), and ALT-positivity (OR 3.486; 95% CI 1.093-11.115; P = 0.035) were independently associated with liver metastases. In the subset assessed by next-generation sequencing and copy number variation analysis, 3 molecular subtypes with differing risks of liver metastases were identified. Group 1 (n = 15; 73% metastasized) was characterized by recurrent chromosomal gains, CN-LOH, DAXX mutations, and ALT-positivity. Group 2 (n = 19; 42% metastasized, including 5 G1 tumors) was characterized by limited copy number alterations and mutations. Group 3 (n = 14; 35% metastasized) were defined by chromosome 11 loss. CONCLUSIONS:We identified genomic patterns of small PanNETs associated with a different risk for liver metastases. Molecular alterations, such as DAXX mutations, chromosomal gains, and ALT, are associated with an increased risk of metastasis in small PanNETs. Therefore, targeted sequencing and/or ALT analysis may help in the clinical decisions for these small PanNETs.
METHODS::Background: This retrospective comparative case series study aims to analyze the pancreatic fistula rates of internal and external stenting of the pancreatojejunostomy (PJ) anastomosis in patients who underwent pancreatoduodenectomy (PD) for periampullary tumors.Methods: Ninety-eight patients with periampullary tumors who were operated between 2010 and 2017 were enrolled in this study. A classic open PD with Roux-en-Y PJ reconstruction was performed in all cases.Results: The PJ anastomosis of 53 patients (54%) were stented internally whereas in 45 patients (46%) external stenting was preferred. Pancreatic fistula was observed in 29 patients (29.6%). Internal stenting and soft pancreatic tissue were found to be related to higher pancreatic fistula rates with odds ratios of 3.27 (p = .024) and 3.4 (p = .017), respectively. When only grade B and grade C fistulas were taken into account, the type of stenting has lost its significance but the texture of the remnant pancreas was still associated with 'clinically important' pancreatic fistula.Conclusions: We concluded that the external stenting of the PJ anastomosis may be considered as an effective approach for reducing postoperative pancreatic leaks in PD-planned patients for periampullary tumors. Although our study was retrospectively designed, we used standard charts to gather patient data and compared two stenting methods among homogeneous patient groups.
METHODS:BACKGROUND:Heavily pretreated pancreatic cancer patients have a grave prognosis. In this case series study, we evaluated the safety and efficacy of nab-paclitaxel-based chemotherapy for such patients. METHODS:The data of pancreatic adenocarcinoma patients (n = 40) treated with nab-paclitaxel after the failure of gemcitabine or fluoropyrimidines at our institution in 2013-2015 were reviewed. RESULTS:The median number of prior chemotherapy regimens was two (range, 1-6). Eighteen patients had an Eastern Cooperative Oncology Group performance status of ≥2. The regimens comprised nab-paclitaxel combined with the following drugs: gemcitabine (n = 28), gemcitabine and fluoropyrimidine (n = 3), platinum and fluoropyrimidine (n = 4), fluoropyrimidine (n = 4), and irinotecan and fluoropyrimidine (n = 1). The median dose of nab-paclitaxel was 63 (range, 51-72) mg/m2/dose, with the schedule of D1/15, D1/8, and D1/8/15 followed in 23, 14, and 3 patients, respectively. The median overall survival was 5.1 (95% CI, 4.6-5.7) months. Among 32 evaluable patients, two partial responses and six stable diseases were observed. The median progression-free survival was 2.6 (95% CI, 1.9-3.2) months. Grade 3/4 leucopenia or neutropenia was observed in three and two patients, respectively. Grade 3/4 anemia was observed in four patients. Other significant (grade 3 or more) nonhematological toxicities were not frequent, except for sepsis/infection (n = 7). However, more severe anemia or sepsis/infection was significantly associated with disease control. CONCLUSION:In heavily pretreated pancreatic adenocarcinoma patients, low-dose nab-paclitaxel-based chemotherapy was fairly tolerable with modest efficacy.