Impact of simultaneous assay, the PCNA, cyclinD1, and DNA content with specimens before and after preoperative radiotherapy on prognosis of esophageal cancer-possible incorporation into clinical TNM staging system

Identification of crucial miRNAs and genes in esophageal squamous cell carcinoma by miRNA-mRNA integrated analysis

Esophageal squamous cell carcinoma (ESCC) is a malignancy that severely threatens human health and carries a high incidence rate and a low 5-year survival rate. MicroRNAs (miRNAs) are commonly accepted as a key regulatory function in human cancer, but the potential regulatory mechanisms of miRNA-mRNA related to ESCC remain poorly understood.The GSE55857, GSE43732, and GSE6188 miRNA microarray datasets and the gene expression microarray datasets GSE70409, GSE29001, and GSE20347 were downloaded from Gene Expression Omnibus databases. The differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) were obtained using GEO2R. Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for DEGs were performed by Database for Annotation, Visualization and Integrated Discovery (DAVID). A protein-protein interaction (PPI) network and functional modules were established using the STRING database and were visualized by Cytoscape. Kaplan-Meier analysis was constructed based on The Cancer Genome Atlas (TCGA) database.In total, 26 DEMs and 280 DEGs that consisted of 96 upregulated and 184 downregulated genes were screened out. A functional enrichment analysis showed that the DEGs were mainly enriched in the ECM-receptor interaction and cytochrome P450 metabolic pathways. In addition, MMP9, PCNA, TOP2A, MMP1, AURKA, MCM2, IVL, CYP2E1, SPRR3, FOS, FLG, TGM1, and CYP2C9 were considered to be hub genes owing to high degrees in the PPI network. MiR-183-5p was with the highest connectivity target genes in hub genes. FOS was predicted to be a common target gene of the significant DEMs. Hsa-miR-9-3p, hsa-miR-34c-3p and FOS were related to patient prognosis and higher expression of the transcripts were associated with a poor OS in patients with ESCC.Our study revealed the miRNA-mediated hub genes regulatory network as a model for predicting the molecular mechanism of ESCC. This may provide novel insights for unraveling the pathogenesis of ESCC.

Exendin-4 improves hepatocyte injury by decreasing proliferation through blocking NGF/TrkA in diabetic mice

The hepatocytes express nerve growth factor (NGF) and its high affinity receptor tyrosine kinase A (TrkA). However, the link between NGF/TrkA system and hepatocyte proliferation in diabetic animals and the effects of exendin-4, a glucagon like peptide-1 (GLP-1) receptor agonist, on this system are not known. BALB/c male mice were divided into four groups. The first group was given citrate buffer only, the second group was administered exendin-4 alone, the third group received streptozotocin (STZ), and the fourth group was given both STZ and exendin-4. Exendin-4 (3μg/kg) was administered by subcutaneous injection daily for 30 days after the animals were rendered diabetic by administration of STZ (200mg/kg). With treatment of exendin-4 to the diabetic mice the following results were noted (i) NGF, TrkA and proliferating cell nuclear antigen positive hepatocytes were decreased; (ii) p75 neurotrophin receptor and caspase-3 positive hepatocyte could not be detected; (iii) liver alanine transaminase and aspartate transaminase activities, lipid peroxidation, protein carbonyl and myeloperoxidase levels were decreased; (iv) liver catalase, superoxide dismutase, glutathione peroxidase activities and glutathione levels were increased. These data suggest that exendin-4 might exerts its anti-proliferative action through blocking NGF/TrkA system and stimulating oxidative defense system in liver of diabetic mice.

PCNA and anti-apoptotic Mcl-1 proteins predict disease-free survival in oral cancer patients treated with definitive radiotherapy

At our laboratory, we recently observed cell cycle and apoptosis-related proteins Myeloid Cell Leukemia-1 (Mcl-1) and Proliferating Cell Nuclear Antigen (PCNA) to be altered in oral tumours/cell lines. The present study aimed to evaluate the above proteins for predicting response and outcome in oral cancer patients treated with definitive radiotherapy. Pre-treatment oral cancer biopsy samples from 39 patients were examined for Mcl-1 and PCNA proteins using immunohistochemistry and correlated with clinico-pathological variables using disease-free survival (DFS) as the primary endpoint. We observed high expression of Mcl-1 in older versus younger patients (p=0.013) and in tobacco chewers+/-alcohol versus smokers+/-alcohol (p=0.037); and PCNA in node-positive versus node-negative tumours (p=0.037). On univariate analysis, high PCNA (p=0.007), Mcl-1 (p=0.050), node positivity (p=0.040) and co-expression of PCNA and Mcl-1 (p=0.008), had a significant impact on DFS. On multivariate analysis, low PCNA/Mcl-1 (p=0.006) co-expressing tumours were associated with improved DFS. Thus our study suggests that in patients undergoing primary radiotherapy, PCNA could be of potential predictive value to identify patients with risk of nodal metastases and in combination with Mcl-1 may have potential prognostic value to differentiate patients with poor DFS. These markers may be used for future trial patients requiring radiotherapy for their treatment.

Esophageal tumor length is independently associated with long-term survival

BACKGROUND

Esophageal cancer staging uses tumor depth as the sole criterion for assessment of the primary tumor (pT). To the authors' knowledge the impact of esophageal tumor length on long-term outcome and the esophageal cancer staging system has not been fully evaluated in the current era.

METHODS

All esophageal cancer patients (n = 209) undergoing surgery from 1995 to 2005 who did not receive preoperative chemotherapy or radiotherapy were reviewed. Maximum esophageal tumor length along a craniocaudal axis was determined pathologically after surgical resection. Univariate and multivariate analyses were used to assess the impact of esophageal tumor length (< or = 3 cm vs >3 cm) on long-term survival.

RESULTS

Esophageal tumor length was closely associated with long-term survival (hazards ratio [HR] of 6.14 [95% confidence interval (95% CI), 4.1-9.25]; 5-year survival: < or = 3 cm = 68%, >3 cm = 10% [P < .001]). Multivariate Cox regression analyses demonstrated tumor length (HR of 2.13 [95% CI, 1.26-3.63]) was found to be a significant independent predictor of long-term survival even when controlled for sex, age, tumor location, histology, margin positivity, surgical procedure, and current pTNM criteria. The incorporation of tumor length in pTNM staging significantly improves the ability to predict the long-term survival of patients (5-year survival for patients with tumors < or = 3 cm and stages I, IIA, IIB, and III disease = 86%, 62%, 49%, and 22%, respectively; survival for patients with tumors measuring >3 cm and stages I, IIA, IIB, and III disease = 27%, 22%, 0%, and 8%, respectively [P < .1]).

CONCLUSIONS

Esophageal tumor length is an independent predictor of long-term survival in the current era and should be considered for incorporation into the current esophageal cancer staging system to better predict long-term survival and identify high-risk patients for postoperative therapy.

Decreased expression of NDRG1 is correlated with tumor progression and poor prognosis in patients with esophageal squamous cell carcinoma

NDRG1 (N-myc downstream regulated gene-1) was reported to be necessary for p53-mediated apoptosis and to be regulated by PTEN (phosphatase and tensin homolog). In several cancers, it was suggested to be a tumor suppressor gene. Its significance in esophageal squamous cell carcinoma (ESCC) has not been studied. The objective of this study was to clarify the relation between clinicopathological and biologic factors in esophageal carcinoma and to determine the prognostic significance of the expression of NDRG1. Expression of NDRG1 mRNA was quantified by real-time reverse transcription polymerase chain reaction using a Lightcycler in 47 esophageal ESCC specimens. The data were analyzed with reference to clinicopathological factors. Among the esophageal cancer tissues, NDRG1 mRNA expression was significantly lower in tumors of more advanced pathological stage (0-I vs. II-IV; P = 0.0027) and local tumor invasion (T1-2 vs. T3-4; P = 0.0136). Patients who had low NDRG1 mRNA expression had a significantly shorter survival after surgery compared with patients who had high NDRG1 mRNA expression (log-rank test, P = 0.0478). Impaired NDRG1 expression may lead to more aggressive invasion of ESCC.