Dataset Information

AEG-1 expression is an independent prognostic factor in rectal cancer patients with preoperative radiotherapy: a study in a Swedish clinical trial.

ABSTRACT:

Background

Preoperative radiotherapy (RT) is widely used to downstage rectal tumours, but the rate of recurrence varies significantly. Therefore, new biomarkers are needed for better treatment and prognosis. It has been shown that astrocyte elevated gene-1 (AEG-1) is a key mediator of migration, invasion, and treatment resistance. Our aim was to analyse the AEG-1 expression in relation to RT in rectal cancer patients and to test its radiosensitising properties.

Methods

The AEG-1 expression was examined by immunohistochemistry in 158 patients from the Swedish clinical trial of RT. Furthermore, we inhibited the AEG-1 expression by siRNA in five colon cancer cell lines and measured the survival after irradiation by colony-forming assay.

Results

The AEG-1 expression was increased in the primary tumours compared with the normal mucosa independently of the RT (P<0.01). High AEG-1 expression in the primary tumour of the patients treated with RT correlated independently with higher risk of distant recurrence (P=0.009) and worse disease-free survival (P=0.007). Downregulation of AEG-1 revealed a decreased survival after radiation in radioresistant colon cancer cell lines.

Conclusions

The AEG-1 expression was independently related to distant recurrence and disease-free survival in rectal cancer patients with RT and could therefore be a marker to discriminate patients for distant relapse.

SUBMITTER: Gnosa S

PROVIDER: S-EPMC4090728 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature

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Publications

AEG-1 expression is an independent prognostic factor in rectal cancer patients with preoperative radiotherapy: a study in a Swedish clinical trial.

Gnosa S S Zhang H H Brodin V P VP Carstensen J J Adell G G Sun X-F XF

British journal of cancer 20140529 1

<h4>Background</h4>Preoperative radiotherapy (RT) is widely used to downstage rectal tumours, but the rate of recurrence varies significantly. Therefore, new biomarkers are needed for better treatment and prognosis. It has been shown that astrocyte elevated gene-1 (AEG-1) is a key mediator of migration, invasion, and treatment resistance. Our aim was to analyse the AEG-1 expression in relation to RT in rectal cancer patients and to test its radiosensitising properties.<h4>Methods</h4>The AEG-1 e ...[more]

PMID: 24874474

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Project description:PurposeThe purpose of this study was to establish the influence of time interval between preoperative hyperfractionated radiotherapy (5 × 5 Gy) and surgery on long-term overall survival (5 years) and recurrence rate in patients with locally advanced rectal cancer operated on according to total mesorectal excision technique.MethodsThe treatment group comprised 154 patients with locally advanced rectal cancer who were operated on between 1999 and 2006 in the 1st Department of General Surgery, Jagiellonian University, Cracow, Poland. The data on survival has been systematically collected until 31st of December 2010. In addition, the following aspects were analyzed: the significance of time interval between the end of radiotherapy and surgical treatment and its influence on downsizing, downstaging, rate of curative resections, and sphincter-sparing procedures. Patients were qualified to preoperative radiotherapy 5 × 5 Gy and then randomly assigned to subgroups with different time intervals between radiotherapy and surgery: one subgroup consisted of 77 patients operated on 7-10 days after the end of irradiation, and the second subgroup consisted of 77 patients operated on after 4-5 weeks. Both groups were homogenous in sex, age, cancer stage and localization, distal and circumferential resection margins, and number of resected lymph nodes.ResultsThe 5-year survival rate in patients operated on 7-10 days after irradiation was 63%, whereas in those operated on after 4-5 weeks, it was 73%-the difference was not statistically significant (log rank, p = 0.24). A statistically significant increase in 5-year survival rate was observed only in patients with downstaging after radiotherapy-90% in comparison with 60% in patients without response to neoadjuvant treatment (log rank, p = 0.004). Recurrence was diagnosed in 13.2% of patients. A lower rate of systemic recurrence was observed in patients operated on 4-5 weeks after the end of irradiation (2.8% vs. 12.3% in the subgroup with a shorter interval, p = 0.035). No differences in local recurrence rates were observed in both subgroups of irradiated patients (p = 0.119). The longer time interval between radiotherapy and surgery resulted in higher downstaging rate (44.2% vs. 13% in patients with a shorter interval, p = 0.0001) although it did not increase the rate of sphincter-saving procedures (p = 0.627) and curative resections (p = 0.132).Conclusions1. Improved 5-year survival rate is observed only in patients with downstaging after preoperative irradiation dose of 25 Gy. 2. Longer time interval after preoperative radiotherapy 25 Gy does not improve the rate of sphincter-saving procedures and curative resections (R0) despite higher downstaging rate observed in this regimen.

Project description:Differential expressions and functions of various micoRNAs (miRNAs) have been intensively studied in both colon and rectal cancers. However, the importance of miRNAs on radiotherapy (RT) response and clinical outcome in rectal cancer patients remains unclear. In this study, we used real-time polymerase chain reaction to examine the expressions of miR-302a, miR-105, and miR-888 in normal mucosa and cancer tissue from rectal cancer patients with and without preoperative RT. The biological function of miR-302a, miR-105, and miR-888 expression was further analyzed and identified through the public databases: TCGA (The Cancer Genome Atlas) and GEPIA (Gene Expression Profiling Interactive Analysis). The results showed that the expression of miR-105 in rectal cancer was higher than that in normal mucosa in RT (P = 0.042) and non-RT patients (P = 0.003) and was associated with mucinous histological type (P = 0.004), COX-2 (P = 0.042), and p73 expression (P = 0.030). The expression of miR-302a was shown more frequently in cancers with necrosis (P = 0.033) and with WRAP53 expression (P = 0.015), whereas miR-888 expression occurred more frequently in tumors with protein the expression of survivin (P = 0.015), AEG-1 (astrocyte elevated gene-1) (P = 0.003), and SATB1 (special AT-rich sequence binding protein 1) (P = 0.036). Moreover, TargetScan also predicted AEG-1 and SATB1 as putative targets for miR-888. The miRNA-gene network analysis showed that ABI2 was associated with all the three miRNAs, with lower expression and good diagnostic value in rectal cancers. The TCGA database demonstrated the association of miR-105 expression with high carcinoembryonic antigen level (P = 0.048). RT reduced the expressions of miR-302a, miR-105, and miR-888. Prognostic analysis showed that miR-888 expression was independently associated with worse survival of patients without RT [overall survival, P = 0.001; disease-free survival, P = 0.009]. Analysis of biological function revealed that the protein serine/threonine kinase activity and PI3K-AKT signaling pathway were the most significantly enriched functions and pathways, respectively. Our findings suggest that miR-105 is involved in rectal cancer pathogenesis and miR-888 is associated with prognosis. MiR-302a, miR-105, and miR-888 have potential influence on the pathogenesis, RT, and prognosis of rectal cancer.

Dataset Information

AEG-1 expression is an independent prognostic factor in rectal cancer patients with preoperative radiotherapy: a study in a Swedish clinical trial.

Background

Methods

Results

Conclusions

Publications

AEG-1 expression is an independent prognostic factor in rectal cancer patients with preoperative radiotherapy: a study in a Swedish clinical trial.

Similar Datasets

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