15 research outputs found

    Epigenetic Regulation of KPC1 Ubiquitin Ligase Affects the NF-κB Pathway in Melanoma.

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    Purpose: Abnormal activation of the NF-κB pathway induces a more aggressive phenotype of cutaneous melanoma. Understanding the mechanisms involved in melanoma NF-κB activation may identify novel targets for this pathway. KPC1, an E3 ubiquitin ligase, is a regulator of the NF-κB pathway. The objective of this study was to investigate the mechanisms regulating KPC1 expression and its clinical impact in melanoma.Experimental Design: The clinical impact of KPC1 expression and its epigenetic regulation were assessed in large cohorts of clinically well-annotated melanoma tissues (tissue microarrays; n = 137, JWCI cohort; n = 40) and The Cancer Genome Atlas database (TCGA cohort, n = 370). Using melanoma cell lines, we investigated the functional interactions between KPC1 and NF-κB, and the epigenetic regulations of KPC1, including DNA methylation and miRNA expression.Results: We verified that KPC1 suppresses melanoma proliferation by processing NF-κB1 p105 into p50, thereby modulating NF-κB target gene expression. Concordantly, KPC1 expression was downregulated in American Joint Committee on Cancer stage IV melanoma compared with early stages (stage I/II P = 0.013, stage III P = 0.004), and low KPC1 expression was significantly associated with poor overall survival in stage IV melanoma (n = 137; HR 1.810; P = 0.006). Furthermore, our data showed that high miR-155-5p expression, which is controlled by DNA methylation at its promoter region (TCGA; Pearson\u27s r -0.455; P \u3c 0.001), is significantly associated with KPC1 downregulation (JWCI; P = 0.028, TCGA; P = 0.003).Conclusions: This study revealed novel epigenetic regulation of KPC1 associated with NF-κB pathway activation, promoting metastatic melanoma progression. These findings suggest the potential utility of KPC1 and its epigenetic regulation as theranostic targets. Clin Cancer Res; 23(16); 4831-42. ©2017 AACR

    Circulating microRNA Biomarkers as Liquid Biopsy for Cancer Patients: Pros and Cons of Current Assays

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    An increasing number of studies have focused on circulating microRNAs (cmiRNA) in cancer patients’ blood for their potential as minimally-invasive biomarkers. Studies have reported the utility of assessing specific miRNAs in blood as diagnostic/prognostic biomarkers; however, the methodologies are not validated or standardized across laboratories. Unfortunately, there is often minimum limited overlap in techniques between results reported even in similar type studies on the same cancer. This hampers interpretation and reliability of cmiRNA as potential cancer biomarkers. Blood collection and processing, cmiRNA extractions, quality and quantity control of assays, defined patient population assessment, reproducibility, and reference standards all affect the cmiRNA assay results. To date, there is no reported definitive method to assess cmiRNAs. Therefore, appropriate and reliable methodologies are highly necessary in order for cmiRNAs to be used in regulated clinical diagnostic laboratories. In this review, we summarize the developments made over the past decade towards cmiRNA detection and discuss the pros and cons of the assays

    Successful covered stent treatment with direct thrombin injection for true deep femoral artery aneurysm: A case report

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    Degenerative aneurysms of the deep femoral artery (DFA) are relatively rare and are rarely recognized until they become symptomatic. The risk of rupture is higher than that of other peripheral aneurysms, and DFAAs > 2 cm in diameter should be treated once diagnosed, even if they are asymptomatic. We report the rare case of an 83-year-old man who was referred to our hospital because of bacterial pneumonia with coma. Whole-body computed tomography revealed a left DFAA. A covered-stent exclusion of the DFAA with direct thrombin injection was successfully performed due to poor surgical risk and anatomical feasibility. The patient remained stable without any additional interventions 14 months after endovascular treatment. Hence, covered-stent placement with direct thrombin injection is a feasible alternative for managing selected peripheral artery aneurysms

    Circulating microRNA Biomarkers as Liquid Biopsy for Cancer Patients: Pros and Cons of Current Assays

    No full text
    An increasing number of studies have focused on circulating microRNAs (cmiRNA) in cancer patients’ blood for their potential as minimally-invasive biomarkers. Studies have reported the utility of assessing specific miRNAs in blood as diagnostic/prognostic biomarkers; however, the methodologies are not validated or standardized across laboratories. Unfortunately, there is often minimum limited overlap in techniques between results reported even in similar type studies on the same cancer. This hampers interpretation and reliability of cmiRNA as potential cancer biomarkers. Blood collection and processing, cmiRNA extractions, quality and quantity control of assays, defined patient population assessment, reproducibility, and reference standards all affect the cmiRNA assay results. To date, there is no reported definitive method to assess cmiRNAs. Therefore, appropriate and reliable methodologies are highly necessary in order for cmiRNAs to be used in regulated clinical diagnostic laboratories. In this review, we summarize the developments made over the past decade towards cmiRNA detection and discuss the pros and cons of the assays

    Genome–Wide Hypomethylation and Specific Tumor-Related Gene Hypermethylation are Associated with Esophageal Squamous Cell Carcinoma Outcome

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    IntroductionEsophageal squamous cell carcinoma (ESCC) is a cancer of variable outcomes with limited effective treatments resulting in poor overall survival (OS). Epigenetic alterations contributing to this deadly cancer type that can be used as novel therapeutic or diagnostic targets are still poorly understood.MethodsWe explored genome-wide DNA methylation data from The Cancer Genome Atlas project and identified a panel of tumor-related genes hypermethylated in ESCC. The methylation statuses of RASSF1, RARB, CDKN2A (p16INK4a, p14ARF), APC, and RUNX3 genes and long interspersed nucleotide element-1 (LINE-1) were validated in a large cohort (n = 140) of clinically well-annotated ESCC specimens and esophageal normal mucosa (n = 28) using a quantitative methylation-specific polymerase chain reaction.ResultsHypermethylation of RARB, p16INK4a, RASSF1, APC, RUNX3, and p14ARF were observed in 55%, 24%, 20%, 19%, 14%, and 8% of specimens, respectively. Hypermethylation of APC was significantly associated with tumor depth (p = 0.02) and American Joint Committee on Cancer stage (p = 0.03). Global DNA methylation level, assessed by LINE-1, was significantly lower in ESCC than in normal mucosa (p < 0.0001), and lower in greater than or equal to T2 (n = 69) than T1 tumors (n = 45; p = 0.03). There was a significant inverse correlation between LINE-1 and RARB methylation (p = 0.008). Importantly, hypermethylation of RASSF1 and APC genes was significantly associated with overall survival (OS; p = 0.006 and p = 0.007, respectively). In addition, patients with tumors containing a higher number of methylated genes (greater than two genes) presented worse OS (p = 0.003).ConclusionsThis study demonstrates that epigenetic alterations of a panel of tumor-related genes and the noncoding region LINE-1 can be used as prognostic indicators and help in clinical management of ESCC patients

    MiR-200a Regulates CDK4/6 Inhibitor Effect by Targeting CDK6 in Metastatic Melanoma.

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    The CDK4/6 pathway is frequently dysregulated in cutaneous melanoma. Recently, CDK4/6 inhibitors have shown promising clinical activity against several cancer types, including melanoma. Here, we show that microRNA-200a decreases CDK6 expression and thus reduces the response of CDK4/6 inhibitor in highly proliferative metastatic melanoma. Down-regulation of microRNA-200a expression in melanoma cells is associated with disease progression and a higher number of lymph node metastases. Furthermore, microRNA-200a expression is epigenetically modulated by both DNA methylation at the promoter region and chromatin accessibility of an upstream genomic region with enhancer activity. Mechanistically, overexpression of miR-200a in metastatic melanoma cells induces cell cycle arrest by targeting CDK6 and decreases the levels of phosphorylated-Rb1 and E2F-downstream targets, diminishing cell proliferation; these effects are recovered by CDK6 overexpression. Conversely, low microRNA-200a expression in metastatic melanoma cells results in higher levels of CDK6 and a more significant response to CDK4/6 inhibitors. We propose that microRNA-200a functions as a cell cycle brake that is lost during melanoma progression to metastasis and provides the ability to identify melanomas that are highly proliferative and more prompted to respond to CDK4/6 inhibitors

    Successful treatment of esophagopleural fistula following pulmonary resection for primary lung cancer: a case report

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    Abstract Background We report a rare case of esophagopleural fistula (EPF) developing during the postoperative period after pulmonary resection for primary lung cancer. Case presentation A 71-year-old male who underwent video-assisted thoracoscopic right lower lobectomy with lymph node dissection for primary lung cancer developed severe stabbing pain in his right shoulder and high fever 3 days after the operation. The fever persisted, the cough became more productive, and a plain chest X-ray showed slight a few infiltrative opacities in the right lung field. Intravenous antibiotic therapy was initiated. The patient developed a right pneumothorax 5 days after the operation, and contaminated discharge from the right chest tube was noted. A chest computed tomography showed right-sided empyema, while bronchoscopic examination revealed no evidence of a bronchopleural fistula. Open-window thoracostomy (OWT) was performed. Finally, 2 days after the OWT, the patient was diagnosed as having an EPF, because the right chest cavity was found to be contaminated with food materials. Ample purification of the right chest cavity was achieved by repeated dressing changes, and the EPF was finally closed by omentopexy. The post-surgical course was uneventful. Five weeks after the omentopexy, an esophagogram revealed no leakage of the contrast medium from the esophageal wall. The patient was discharged 13 weeks after the omentopexy. Conclusion While EPF following pulmonary resection is a rare complication, it can lead to critical situations and the diagnosis is difficult. Prompt OWT and omentopexy were found to be effective treatment procedures for EPF following lung surgery

    Regulation of MRE11A by UBQLN4 leads to cisplatin resistance in patients with esophageal squamous cell carcinoma

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    Resistance to standard cisplatin-based chemotherapies leads to worse survival outcomes for patients with esophageal squamous cell carcinoma (ESCC). Therefore, there is an urgent need to understand the aberrant mechanisms driving resistance in ESCC tumors. We hypothesized that ubiquilin-4 (UBQLN4), a protein that targets ubiquitinated proteins to the proteasome, regulates the expression of Meiotic Recombination 11 Homolog A (MRE11A), a critical component of the MRN complex and DNA damage repair pathways. Initially, immunohistochemistry analysis was conducted in specimens from patients with ESCC (n = 120). In endoscopic core ESCC biopsies taken from 61 patients who underwent neoadjuvant chemotherapy (NAC) (5-fluorouracil and cisplatin), low MRE11A and high UBQLN4 protein levels were associated with reduced pathological response to NAC (P P < 0.001, respectively). Multivariable analysis of surgically resected ESCC tissues from 59 patients revealed low MRE11A and high UBLQN4 expression as independent factors that can predict shorter overall survival [P = 0.01, hazard ratio (HR) = 5.11, 95% confidence interval (CI), 1.45-18.03; P = 0.02, HR = 3.74, 95% CI, 1.19-11.76, respectively]. Suppression of MRE11A expression was associated with cisplatin resistance in ESCC cell lines. Additionally, MRE11A was found to be ubiquitinated after cisplatin treatment. We observed an amplification of UBQLN4 gene copy numbers and an increase in UBQLN4 protein levels in ESCC tissues. Binding of UBQLN4 to ubiquitinated-MRE11A increased MRE11A degradation, thereby regulating MRE11A protein levels following DNA damage and promoting cisplatin resistance. In summary, MRE11A and UBQLN4 protein levels can serve as predictors for NAC response and as prognostic markers in ESCC patients
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