Renato Moretti

herg1 Gene and HERG1 Protein Are Overexpressed in Colorectal Cancers and Regulate Cell Invasion of Tumor Cells

The acquisition of the capacity to invade surrounding tissues confers a more malignant phenotype to tumor cells and is necessary for the establishment of metastases. The understanding of the molecular mechanisms underlying cell invasion in human solid tumors such as colorectal cancers could provide not only more sensitive prognostic analyses but also novel molecular targets for cancer therapy. We report in this article that K+ ion channels belonging to the HERG family are important determinants for the acquisition of an invasive phenotype in colorectal cancers. The herg1 gene and HERG1 protein are expressed in many colon cancer cell lines, and the activity of HERG channels modulates colon cancer cell invasiveness. Moreover, the amount of HERG1 protein expressed on the plasma membrane is directly related to the invasive phenotype of colon cancer cells. Finally, both the herg1 gene and HERG1 protein were expressed in a high percentage of primary human colorectal cancers, with the highest incidence occurring in metastatic cancers, whereas no expression could be detected either in normal colonic mucosa or in adenomas.

Polymorphic DNA repair and metabolic genes: a multigenic study on gastric cancer

Risk factors for gastric cancer (GC) include inter-individual variability in the inflammatory response to Helicobacter pylori infection, in the ability of detoxifying DNA reactive species and repairing DNA damage generated by oxidative stress and dietary carcinogens. To evaluate the association between polymorphic DNA repair genes and GC risk, a case-control study including 314 histologically confirmed GC patients and 548 healthy controls was conducted in a GC high-risk area in Tuscany, Italy. Polymorphic variants of base excision repair (APE1-D148E, XRCC1-R194W, XRCC1-R399Q and OGG1-S326C), nucleotide excision repair (XPC-PAT, XPA-23G>A, ERCC1-19007T>C and XPD-L751Q), recombination (XRCC3-T241M) and alkylation damage reversal (MGMT-L84F) were tested for their potential role in the development of GC by using logistic regression models. The same population was also characterised for GSTT1 and GSTM1 variant alleles to search for possible functional interactions between metabolic and DNA repair genotypes by two-way interactions using multivariate logistic models. No significant association between any single DNA repair genotype and GC risk was detected with a borderline association with the XPC-PAT homozygous genotype [odds ratio (OR) =1.42; 95% confidence interval (CI) 0.94-2.17]. Gene-gene interaction analysis revealed combinations of unfavourable genotypes involving either multiple DNA repair polymorphisms or DNA repair and GST-specific genotypes. The combination of the XPC-PAT and the XPA variant alleles significantly increased GC risk (OR=2.15; 95% CI 1.17-3.93, P=0.0092). A significant interaction was also found between the APE1 wild-type genotype and either the single GSTT1 (OR=4.90; 95% CI 2.38-10.11, P=0.0079) or double GSTM1-GSTT1 null (OR=7.84; 95% CI 3.19-19.22, P=0.0169) genotypes or the XPA-mutant allele (OR=3.56; 95% CI 1.53-8.25, P=0.0012). These findings indicate that a complex interaction between host factors such as oxidative stress, antioxidant capacity and efficiency of multiple DNA repair pathways underlies the inter-individual variability in GC risk.

Predictors of recurrence after laparoscopic ventral hernia repair.

Laparoscopic ventral hernia repair (LVHR) is widely used to manage ventral hernias, but predictors of hernia recurrence have been poorly investigated. This retrospective study investigated the influence of common risk factors on hernia recurrence. Data from 146 consecutive, unselected patients who underwent LVHR between 2000 and 2006 were collected. Demographic, clinical, and perioperative parameters were analyzed to identify predictable risk factors for hernia recurrence. Both univariate and multivariate Coxs regression analysis were employed. The overall recurrence rate was 8% (12 patients) after an average follow-up of 45 months. On univariate analysis, smoking (P=0.01) and earlier repair (P<0.00) were significantly different in recurred patients. However, only earlier repair was an independent predictor of multivariate Coxs regression analysis (hazard ratio 0.085, 95% confidence interval: 0.020-0.355; P=0.001). LVHR is a safe technique to repair ventral hernias. However, smokers with earlier failed repair attempts have a higher risk of recurrence.

Modular branched neurotensin peptides for tumor target tracing and receptor-mediated therapy: a proof-of-concept.

The aim of this study was to demonstrate that oligo-branched peptides can be effective either for spotlighting tumor cells that overexpress peptide receptors, or for killing them, simply by exchanging the functional moiety coupled to the conserved receptor-targeting core. Tetra-branched peptides containing neurotensin (NT) sequence are described here as selective targeting agents for human colon, pancreas and prostate cancer. Fluorophore-conjugated peptides were used to measure tumor versus healthy tissue binding in human surgical samples, resulting in validation of neurotensin receptors as highly promising tumor-biomarkers. Drug-armed branched peptides were synthesized with different conjugation methods, resulting in uncleavable adducts or drug-releasing molecules. Cytotoxicity on human cell lines from colon (HT-29), pancreas (PANC-1) or prostate (PC-3) carcinoma indicated branched NT conjugated with MTX and 5-FdU as the most active agents on PANC-1 (EC(50) 4.4e-007 M) and HT-29 (1.1e-007 M), respectively. Tetra-branched NT armed with 5-FdU was used for in vivo experiments in HT-29-xenografted mice and produced a 50% reduction in tumor growth with respect to animals treated with the free drug. An unrelated branched peptide carrying the same drug was completely ineffective. In vitro and in vivo results indicated that branched peptides are valuable tools for tumor selective targeting.

Laparoscopic treatment of ventral hernias: prospective evaluation.

We describe 50 patients who recently underwent laparoscopic surgery. Early results, complications, and follow-up data were collected prospectively. Of 50 patients, 34 had an incisional hernia, whereas 16 had a primary defect. Three trocars were inserted. EndoShears or Ultracision was used for tissue manipulation. The prosthetic mesh used was an expanded polytetrafluoroethylene (ePTFE) mesh, inserted through the first trocar and fixed with a helicoidal stapler. Patients were followed-up in the outpatient clinic (mean, 14 months). Every operation was successfully completed, and mean operative time was 103 minutes. There were two small bowel injuries (4%) repaired by minilaparotomy. Postoperative pain was limited. Bowel movements, ambulation, and discharge were prompt. We noted 4 cases of urinary retention (8%), 8 seromas (16%), and 1 prolonged ileus, which resolved on day 5 spontaneously. Mean postoperative stay was 4 days. One patient was readmitted after 4 weeks because of incomplete obstruction, resolved conservatively. There has been only 1 recurrence (2%), 8 months after the operation. The technique appears safe and efficacious.

Comparison of laparoscopic and open repair for primary ventral hernias.

We designed a retrospective clinical trial comparing laparoscopic primary ventral hernia repair (LPVHR) and open traditional repair (OPVHR). Demographics, perioperative data, results, and follow-up were examined to determine if there was any difference in the main outcomes. From January 2000 to December 2006, 28 consecutive, unselected patients, who successfully underwent LPVHR, were matched with 36 patients, who received OPVHR (with mesh) during the same period. The operating room records, clinical files, and outpatient sheets were examined. Patient demographics, results, and follow-up were compared in the 2 groups. Demographic characteristics, site of hernia, concomitant surgery, and defect size were comparable between the 2 groups, but the proportion of urgent procedures was higher in OPVHR patients (25% vs. 4%; P=0.03). The overall complication rates were similar, with some specific differences, whereas analgesic requirement and hospital stay were also comparable. The operative times were significantly longer for the LPVHR group (70 min vs. 35 min; P<0.000). Four recurrences were noted in both OPVHR and LPVHR patients, 11% versus 14%, respectively, with no significant difference (P=0.67). LPVHR seemed to be as safe as the OVHR in this study, although LPVHR increased operative time. The complications of each method should be taken into consideration before making the choice of the surgical approach.

The torsion of a wandering pelvic spleen: A case report

A 15 years old patient was taken to the operative room for an explorative laparotomy due to abdominal pain and a pelvic spleen at preoperative computed tomography: was pointed out the absence of all splenic ligamentous attachments and short gastric vessels with a consequently dislocation of a bigger and congested spleen in the pelvis. This organ, wrapped in the omentum, was in a serious ischemic suffering due to a 720 degrees clock torsion around its exceptionally long pedicle (about 20 cm); besides was confirmed pancreatic body and tail ectopy. Following the derotation, the volume of the organ has decreased but became fixed in above norm dimensions. A total splenectomy was executed.

Laparoscopic cholecystectomy: retrospective comparative evaluation of titanium versus absorbable clips.

We present a retrospective study of the use of titanium and absorbable clips during laparoscopic cholecystectomy. The aim was to determine any differences in outcome and costs. From January 1999 to February 2002, 690 patients who had successfully undergone a laparoscopic cholecystectomy were reviewed. According to the type of clip, we retrospectively identified two groups of patients: 199 in whom the surgeons had used absorbable clips (absorbable clip group, ACG) and 491 in whom the surgeons had used titanium nonabsorbable clips (titanium clip group, TCG). Data about demographics, operation, results, complications, and follow-up were collected and matched in the two groups. Demographics, concomitant surgery, and the American Society of Anesthesiologists (ASA) status were comparable between the two groups. Although the proportions of cases requiring urgent operation, intraoperative cholangiography, use of a fourth trocar, and use of drainage suction were similar, the difficulty score of the operation was lower (6.3 vs. 7.0, P =.03) and the operative time was shorter (44 vs. 61 minutes, P <.0001) in the ACG than in the TCG. Complications, hospital stay, and long-term results were satisfactory and comparable between the two groups. No correlation was found between clip type and the incidence of biliary tree injuries, bleeding, wound infection, or readmission. The cost of the two types of clips varied slightly (90 euros for each procedure). Despite the fact that absorbable clips are theoretically less likely to cause complications than metallic ones, we were not able to demonstrate any clinical advantage during laparoscopic cholecystectomy in this retrospective study. Furthermore, the results suggest that absorbable clips are preferred when the cholecystectomy presents fewer difficulties.

The CHOLEGAS study: multicentric randomized, blinded, controlled trial of gastrectomy plus prophylactic cholecystectomy versus gastrectomy only, in adults submitted to gastric cancer surgery with curative intent.

BackgroundThe incidence of gallstones and gallbladder sludge is known to be higher in patients after gastrectomy than in general population. This higher incidence is probably related to surgical dissection of the vagus nerve branches and the anatomical gastrointestinal reconstruction. Therefore, some surgeons perform routine concomitant cholecystectomy during standard surgery for gastric malignancies. However, not all the patients who are diagnosed to have cholelithiasis after gastric cancer surgery will develop symptoms or require additional surgical treatments and a standard laparoscopic cholecystectomy is feasible even in those patients who underwent previous gastric surgery. At the present, no randomized study has been published and the decision of gallbladder management is left to each surgeon preference.DesignThe study is a randomized controlled investigation. The study will be performed in the General and Oncologic Surgery, Department of Oncology – Azienda Ospedaliero-Universitaria Careggi – Florence – Italy, a large teaching institution, with the participation of all surgeons who accept to be involved in, together with other Italian Surgical Centers, on behalf of the GIRCG (Italian Research Group for Gastric Cancer).The patients will be randomized into two groups: in the first group the patient will be submitted to prophylactic cholecystectomy during standard surgery for curable gastric cancer (subtotal or total gastrectomy), while in the second group he/she will be submitted to standard gastric surgery only.Trial RegistrationClinicalTrials.gov ID. NCT00757640

Abstract A20: Tumor selective delivery of chemotherapeutics via branched peptides

Oligo-branched peptides, containing the sequence of the human regulatory peptide neurotensin (NT), have been used as specific tumor targeting agents, able to selectively and specifically deliver effector units for cell imaging or killing, to tumor cells that over-express NT receptors. Tetra-branched peptides containing neurotensin (NT) sequence are described here as selective targeting agents for human colon, pancreas and prostate cancer. Fluorophore-conjugated peptides were used to measure tumor versus healthy tissue binding in human surgical samples, resulting in validation of neurotensin receptors as highly promising tumor-biomarkers. Drug-armed branched peptides were synthesized with different conjugation methods, resulting in uncleavable adducts or drug-releasing molecules. Human cell lines from colon (HT-29), pancreas (PANC-1) or prostate (PC-3) carcinoma were challenged with branched NT conjugated with 6-mercaptopurin, combretastain A-4, monastrol and 5-fluoro-deoxyuridine. Results indicated that branched NT conjugated with combretastain A-4 and 5-fluoro-deoxyuridine are the most active agents on HT-29 (EC50 1.1e-007 M) and PANC-1 (EC50 5.0e-007 M) respectively. Tetra-branched NT armed with 5-FdU was used for in vivo experiments in HT-29-xenografted mice and produced a 50% reduction in tumor growth with respect to animals treated with the free drug. An unrelated branched peptide carrying the same drug was completely ineffective. In vitro and in vivo results indicated that branched peptides are valuable tools for tumor selective targeting. The results reported in this presentation tell that branched-armed peptides are very promising pharmacodelivery options. Citation Information: Clin Cancer Res 2010;16(7 Suppl):A20