Stefan Post

MicroRNA-21 (miR-21) post-transcriptionally downregulates tumor suppressor Pdcd4 and stimulates invasion, intravasation and metastasis in colorectal cancer

Tumor-suppressor Pdcd4 inhibits transformation and invasion and is downregulated in cancers. So far, it has not been studied as to whether miRNAs, suppressing target expression by binding to the 3′-UTR, regulate Pdcd4 or invasion. The present study was conducted to investigate the regulation of Pdcd4, and invasion/intra-vasation, by miRNAs. A bioinformatics search revealed a conserved target-site for miR-21 within the Pdcd4-3′-UTR at 228–249 nt. In 10 colorectal cell lines, an inverse correlation of miR-21 and Pdcd4-protein was observed. Transfection of Colo206f-cells with miR-21 significantly suppressed a luciferase-reporter containing the Pdcd4-3′-UTR, whereas transfection of RKO with anti-miR-21 increased activity of this construct. This was abolished when a construct mutated at the miR-21/nt228–249 target site was used instead. Anti-miR-21-transfected RKO cells showed an increase of Pdcd4-protein and reduced invasion. Moreover, these cells showed reduced intra-vasation and lung metastasis in a chicken–embryo–metastasis assay. In contrast, overexpression of miR-21 in Colo206f significantly reduced Pdcd4-protein amounts and increased invasion, while Pdcd4-mRNA was unaltered. Resected normal/tumor tissues of 22 colorectal cancer patients demonstrated an inverse correlation between miR-21 and Pdcd4-protein. This is the first study to show that Pdcd4 is negatively regulated by miR-21. Furthermore, it is the first report to demonstrate that miR-21 induces invasion/intravasation/metastasis.

Long-term results of partial pancreaticoduodenectomy for ductal adenocarcinoma of the pancreatic head: 25-year experience.

The prognosis of patients who undergo resection for pancreatic ductal adenocarcinoma with curative intention is generally poor unless they have early-stage disease. Based on our 25-year experience, the results of 194 patients after a standardized Kausch-Whipple resection for adenocarcinoma of the pancreatic head were analyzed and the prognostic factors were evaluated. Between 1972 and 1998 a total of 221 patients were diagnosed for ductal adenocarcinoma of the pancreatic head, and 194 of them subsequently underwent a standardized Kausch-Whipple resection. Long-term results and prognostic factors were examined by multivariate and univariate analyses. The overall postoperative mortality was 3.09%, and the morbidity was 29.9%. By multivariate analysis only curative resection (R0) was significantly related to a favorable prognosis (p < 0.0001). Furthermore, in case of a curative resection, the presence of lymph node metastases showed prognostic significance in the multivariate analysis (p = 0.005). Cumulative survival analysis revealed a 5-year survival rate of 25.4%, a 7-year survival rate of 12.3%, and a 10-year survival rate of 8.2% for patients who underwent curative resection (R0) for adenocarcinoma of the pancreatic head. We demonstrated that the R0 status is the only independent prognostic factor after surgery for adenocarcinoma of the pancreatic head. In the case of a curative resection, the presence of lymph node metastases is of prognostic relevance. In view of considerable surgical morbidity and mortality, resection for cancer of the pancreatic head is the only option if the lesion is resectable. We concluded that surgical treatment is “as good as it gets,” as extended techniques have not proved to produce better results.

Chemoradiotherapy with capecitabine versus fluorouracil for locally advanced rectal cancer: a randomised, multicentre, non-inferiority, phase 3 trial

BACKGROUND Fluorouracil-based chemoradiotherapy is regarded as a standard perioperative treatment in locally advanced rectal cancer. We investigated the efficacy and safety of substituting fluorouracil with the oral prodrug capecitabine. METHODS This randomised, open-label, multicentre, non-inferiority, phase 3 trial began in March, 2002, as an adjuvant trial comparing capecitabine-based chemoradiotherapy with fluorouracil-based chemoradiotherapy, in patients aged 18 years or older with pathological stage II-III locally advanced rectal cancer from 35 German institutions. Patients in the capecitabine group were scheduled to receive two cycles of capecitabine (2500 mg/m(2) days 1-14, repeated day 22), followed by chemoradiotherapy (50·4 Gy plus capecitabine 1650 mg/m(2) days 1-38), then three cycles of capecitabine. Patients in the fluorouracil group received two cycles of bolus fluorouracil (500 mg/m(2) days 1-5, repeated day 29), followed by chemoradiotherapy (50·4 Gy plus infusional fluorouracil 225 mg/m(2) daily), then two cycles of bolus fluorouracil. The protocol was amended in March, 2005, to allow a neoadjuvant cohort in which patients in the capecitabine group received chemoradiotherapy (50·4 Gy plus capecitabine 1650 mg/m(2) daily) followed by radical surgery and five cycles of capecitabine (2500 mg/m(2) per day for 14 days) and patients in the fluorouracil group received chemoradiotherapy (50·4 Gy plus infusional fluorouracil 1000 mg/m(2) days 1-5 and 29-33) followed by radical surgery and four cycles of bolus fluorouracil (500 mg/m(2) for 5 days). Patients were randomly assigned to treatment group in a 1:1 ratio using permuted blocks, with stratification by centre and tumour stage. The primary endpoint was overall survival; analyses were done based on all patients with post-randomisation data. Non-inferiority of capecitabine in terms of 5-year overall survival was tested with a 12·5% margin. This trial is registered with ClinicalTrials.gov, number NCT01500993. FINDINGS Between March, 2002, and December, 2007, 401 patients were randomly allocated; 392 patients were evaluable (197 in the capecitabine group, 195 in the fluorouracil group), with a median follow-up of 52 months (IQR 41-72). 5-year overall survival in the capecitabine group was non-inferior to that in the fluorouracil group (76% [95% CI 67-82] vs 67% [58-74]; p=0·0004; post-hoc test for superiority p=0·05). 3-year disease-free survival was 75% (95% CI 68-81) in the capecitabine group and 67% (59-73) in the fluorouracil group (p=0·07). Similar numbers of patients had local recurrences in each group (12 [6%] in the capecitabine group vs 14 [7%] in the fluorouracil group, p=0·67), but fewer patients developed distant metastases in the capecitabine group (37 [19%] vs 54 [28%]; p=0·04). Diarrhoea was the most common adverse event in both groups (any grade: 104 [53%] patients in the capecitabine group vs 85 [44%] in the fluorouracil group; grade 3-4: 17 [9%] vs four [2%]). Patients in the capecitabine group had more hand-foot skin reactions (62 [31%] any grade, four [2%] grade 3-4 vs three [2%] any grade, no grade 3-4), fatigue (55 [28%] any grade, no grade 3-4 vs 29 [15%], two [1%] grade 3-4), and proctitis (31 [16%] any grade, one [<1%] grade 3-4 vs ten [5%], one [<1%] grade 3-4) than did those in the fluorouracil group, whereas leucopenia was more frequent with fluorouracil than with capecitabine (68 [35%] any grade, 16 [8%] grade 3-4 vs 50 [25%] any grade, three [2%] grade 3-4). INTERPRETATION Capecitabine could replace fluorouracil in adjuvant or neoadjuvant chemoradiotherapy regimens for patients with locally advanced rectal cancer. FUNDING Roche Pharma AG (Grenzach-Wyhlen, Germany).

Randomized clinical trial of lightweight composite mesh for Lichtenstein inguinal hernia repair

Almost half the patients who undergo hernia repair with mesh report a feeling of stiffness and a foreign body in the groin. This study evaluated whether patients noticed any difference between lightweight and standard polypropylene mesh for the repair of inguinal hernia.

High expression of vascular endothelial growth factor predicts early recurrence and poor prognosis after curative resection for ductal adenocarcinoma of the pancreas.

Introduction and Aims Only curative resection for pancreatic adenocarcinoma is related to a favorable prognosis, but the overall survival after surgery still remains poor, and early recurrence is frequently observed. Because recurrence is the limiting factor and the main cause of death after curative resection, the identification of markers that predict early postoperative recurrence is of paramount importance. Angiogenesis is essential for tumor growth and metastases; therefore, we set out to clarify whether vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) correlate with early recurrence and poor prognosis after curative resection. A second goal was to characterize the VEGF-producing cells and the subcellular distribution. Methodology Seventy patients with ductal adenocarcinoma of the pancreas were studied after curative resection with a follow-up of at least 2 years. The MVD quantification was performed immunohistochemically with use of a monoclonal antibody to CD34. The VEGF expression was studied with use of polyclonal antibody. To detect the intracellular localization of specific VEGF mRNA sequences, nonisotopic in situ hybridization was performed. The correlations among VEGF expression and MVD, clinicopathologic parameters, and clinical outcome were then statistically analyzed. Results The VEGF immunoreactivity was 88.6%, and positive mRNA signals were obtained in the cytoplasm of carcinoma and endothelial cells in 81.4%. Furthermore, we observed tumor-associated macrophages close to infiltrating carcinoma cells. All endothelial cells showed positive immunoreactivity to the anti-CD34 antibody, and a median distribution of 85 vessels/×200 field was observed. A significant correlation (p < 0.05) was found between the MVD and the International Union Against Cancer (UICC) stage. Statistical analysis showed a significant correlation between VEGF expression and the height of MVD (p < 0.05). Kaplan–Meier analyses revealed that VEGF expression and MVD had a statistically significant correlation with survival after curative resection (p < 0.05). Furthermore, multivariate analysis indicated that VEGF expression is an independent prognostic marker for cancer recurrence within 8 months after curative surgery (p = 0.003). Conclusion In pancreatic adenocarcinoma, the VEGF expression and the height of MVD are closely correlated, and both—rather than UICC stage and TNM classification (tumor size and nodal involvement)—are markers of prognostic relevance after curative resection. Furthermore, VEGF is a predictor of early recurrence after curative resection. The current study indicates that VEGF may promote the distribution of metastases, leading to early cancer recurrence and poor outcome.

Loss of programmed cell death 4 expression marks adenoma-carcinoma transition, correlates inversely with phosphorylated protein kinase b, and is an independent prognostic factor in resected colorectal cancer

Programmed cell death 4 (Pdcd4) inhibits malignant transformation, and initial studies of Pdcd4 suggested the regulation of Pdcd4 localization by protein kinase B (Akt). However, supporting patient tissue data are missing, and the diagnostic/prognostic potential of Pdcd4 rarely has been studied. The objectives of the current were 1) to determine Pdcd4 as a diagnostic marker in the adenoma‐carcinoma sequence, 2) to support phosphorylated Akt (pAkt)‐mediated Pdcd4 regulation in vivo, and 3) to obtain the first prognostic evidence of Pdcd4 in colorectal cancer.

Tumor suppressor Pdcd4 inhibits invasion/intravasation and regulates urokinase receptor (u-PAR) gene expression via Sp-transcription factors

Tumor suppressor Pdcd4 has recently been shown to inhibit invasion by activating activator protein-1 (AP-1); however, little is known of the functionally significant Pdcd4-target genes. The urokinase receptor (u-PAR) promotes invasion/metastasis, and is associated with poor cancer-patient survival. The present study was conducted (1) to investigate a role for Pdcd4 in intravasation, invasion and u-PAR regulation, and (2) to describe mechanisms by which this is achieved. Fourteen cell lines showed reciprocal expression of u-PAR/Pdcd4. Resected tumor/normal tissues of 29 colorectal cancer patients demonstrated a significant inverse correlation between Pdcd4/u-PAR. siRNA-Pdcd4-transfected GEO cells significantly increased endogenous u-PAR mRNA/protein. A u-PAR-promoter-chloramphenicol acetyl transferase (CAT)-reporter was reduced in activity with increasing Pdcd4 expression in RKO. Deletion of a putative Sp-1-binding site (−402/−350) inhibited u-PAR promoter regulation by Pdcd4, this being paralleled by a reduction of Sp1 binding to this region in pdcd4-transfected cells. Pdcd4-transfected cells showed an increase in Sp3 binding to u-PAR promoter region −152/−135, the deletion of which reduces the ability of Pdcd4 to suppress u-PAR promoter activity. Surprisingly, the u-PAR-AP-1 site was not targeted by Pdcd4. Finally, RKO cells overexpressing Pdcd4 showed an inhibition of invasion/intravasation (chicken embryo metastasis assay). These data suggest Pdcd4 as a new negative regulator of intravasation, and qas the invasion-related gene u-PAR. It is the first study to implicate Pdcd4 regulation of gene expression via Sp1/Sp3.

Endoclipping of iatrogenic colonic perforation to avoid surgery

BackgroundColonoscopy is an established tool for the diagnosis and management of colonic and rectal pathology. Even though colonic perforation is rare after colonoscopy, it is a serious and typical complication. The definitive management remains controversial. Both operative and nonoperative techniques have been described in the literature, though the standard treatment for these patients is still an operative repair of the perforation site. Recently, endoscopic clip application was recommended, particularly for iatrogenic perforations, but less is known about the effectiveness of endoluminal repair of colonic perforations with clips.MethodsIn this series, 7589 colonoscopies were performed over a 34-month period in a tertiary-level referral center. Three perforations occurred during 5413 diagnostic colonoscopies. Therapeutic colonoscopy was under taken in 2176 patients, resulting in a total of 27 perforations. Out of 30 patients with colonic perforation, five patients underwent operative management and 25 patients were subsequently treated nonoperatively.ResultsIn 27 patients, endoscopic application of inert metallic clips was used for closure of iatrogenic perforation. Twenty-five of these patients were treated non-operatively, while two patients underwent surgery. The mean postoperative length of hospitalization for patients was 12.2 days, compared to 3.5 days for patients treated conservatively.ConclusionsEndoluminal repair of colonic perforations with clips and further conservative treatment seems to provide a tool that avoids the major additional trauma associated with laparotomy or laparoscopy and minimizes the length of hospitalization.

The Impact Of Arterialization On Hepatic Microcirculation And Leukocyte Accumulation After Liver Transplantation In The Rat

This study investigated the influence of hepatic arterialization on early graft function, microcirculation, and leukocyte-endothelial interaction after syngeneic orthotopic liver transplantation in Lewis rats. Livers were preserved for 17 hr in UW solution and transplanted without rearterialization (group 1: n = 10) or with immediate arterial reconstruction (group 2: n = 10). Graft function was analyzed by bile flow; microcirculation was assessed by laser Doppler flowmetry (LDF) and intravital microscopy (IVM). In addition, flow behavior of leukocytes was quantified by IVM after i.v. injection of the WBC marker acridine orange. Improved graft function in group 2 was indicated by increased bile production during the observation period of 90 min after reperfusion (7.18±0.62 vs. 3.63±0.63 ml/100 g liver [mean ± SEM] P<0.001). In arterialized grafts LDF values increased by 22.9±3.8% upon reperfusion of the hepatic artery (P=0.004). Arterialization increased WBC velocities in sinusoids (group 1: 0.29±0.02 mm/sec, group 2: 0.34±0.01 mm/sec, P<0.001) and postsinusoidal venules (0.43±0.05 vs. 0.64±0.05 mm/sec, P=0.029). In addition, the number of nonperfused midzonal sinusoids decreased significantly (8.5±2.2% of all sinusoids analyzed vs. 4.2±1.3%, P=0.048). However, the marked sinusoidal and venular WBC adherence observed 1 hr after reperfusion was not altered by arterialization. It is concluded that arterial reconstruction in rat liver transplantation improves microvascular perfusion and graft function but this improvement does not relate to WBC accumulation within the graft. We propose that studies on hepatic preservation and postischemic reperfusion in the rat should be based on the physiological model of dual vascularization.

Retraction: The Influence of Early Supplementation of Parenteral Nutrition on Quality of Life and Body Composition in Patients With Advanced Cancer

The authors of the above article have requested its withdrawal, notifying the Journal that the clinical trials described in the article were not conducted as written in the article. The Editor-in-Chief, the American Society for Parenteral and Enteral Nutrition, and the Publisher have determined to retract the article.