N6-Isopentenyladenosine Impairs Mitochondrial Metabolism through Inhibition of EGFR Translocation on Mitochondria in Glioblastoma Cells

Glioblastoma multiforme (GBM) is the most aggressive malignant brain tumor and is poorly susceptible to cytotoxic therapies. Amplification of the epidermal growth factor receptor (EGFR) and deletion of exons 2 to 7, which generates EGFR variant III (vIII), are the most common molecular alterations of GBMs that contribute to the aggressiveness of the disease. Recently, it has been shown that EGFR/EGFRvIII-targeted inhibitors enhance mitochondrial translocation by causing mitochondrial accumulation of these receptors, promoting the tumor drug resistance; moreover, they negatively modulate intrinsic mitochondria-mediated apoptosis by sequestering PUMA, leading to impaired apoptotic response in GBM cells. N6-isopentenyladenosine (i6A or iPA), a cytokinin consisting of an adenosine linked to an isopentenyl group deriving from the mevalonate pathway, has antiproliferative effects on numerous tumor cells, including GBM cells, by inducing cell death in vitro and in vivo. Here, we observed that iPA inhibits the mitochondrial respiration in GBM cells by preventing the translocation of EGFR/EGFRvIII to the mitochondria and allowing PUMA to interact with them by promoting changes in mitochondrial activity, thus playing a critical role in cell death. Our findings clearly demonstrate that iPA interferes with mitochondrial bioenergetic capacity, providing a rationale for an effective strategy for treating GBM.

N6-Isopentenyladenosine Hinders the Vasculogenic Mimicry in Human Glioblastoma Cells through Src-120 Catenin Pathway Modulation and RhoA Activity Inhibition

BACKGROUND

Vasculogenic mimicry (VM) is a functional microcirculation pattern formed by aggressive tumor cells. Thus far, no effective drugs have been developed to target VM. Glioblastoma (GBM) is the most malignant form of brain cancer and is a highly vascularized tumor. Vasculogenic mimicry represents a means whereby GBM can escape anti-angiogenic therapies.

METHODS

Here, using an in vitro tube formation assay on Matrigel, we evaluated the ability of N6-isopentenyladenosine (iPA) to interfere with vasculogenic mimicry (VM). RhoA activity was assessed using a pull-down assay, while the modulation of the adherens junctions proteins was analyzed by Western blot analysis.

RESULTS

We found that iPA at sublethal doses inhibited the formation of capillary-like structures suppressing cell migration and invasion of U87MG, U343MG, and U251MG cells, of patient-derived human GBM cells and GBM stem cells. iPA reduces the vascular endothelial cadherin (VE-cadherin) expression levels in a dose-dependent manner, impairs the vasculogenic mimicry network by modulation of the Src/p120-catenin pathway and inhibition of RhoA-GTPase activity.

CONCLUSIONS

Taken together, our results revealed iPA as a promising novel anti-VM drug in GBM clinical therapeutics.

Brain Radionecrosis After Adjuvant Radiation Therapy for a Primary Intracerebral Undifferentiated Sarcoma

BACKGROUND

Primary intracranial sarcomas of the central nervous system are rare tumors. They mainly arise from intracranial mesenchymal tissue present in the meninges and can occur at any age. Sometimes osteosarcoma can involve the skull rather than long body bones. In this latter case it is the more common subtype. Surgery, when possible, is a mandatory option often associated with radiation therapy (RT) and chemotherapy. Brain radionecrosis (BRN) is commonly observed due to the growing use of radiosurgery and higher cumulative doses of radiation therapy. The combination of perfusion magnetic resonance imaging and ¹⁸fluoro-deoxy-glucose positron emission tomography can help to differentiate tumor progression from radiation injury. Steroids, anticoagulants, and bevacizumab usually control BRN. However, BRN can also have an unfavorable course.

CASE DESCRIPTION

Here, we present a case of a 60-year-old male who underwent surgery for a brain tumor. The examination showed a primary undifferentiated high-grade sarcoma. Adjuvant RT was given with a total dose of 60 Gy. Six months later, the patient underwent a second surgery that revealed a BRN progressing despite different pharmacologic attempts.

CONCLUSIONS

Primary intracranial sarcomas of the central nervous system are less prevalent among older adults with respect to the younger population. The use of RT alone or combined with chemotherapy is aimed at prolonging survival. However, it is not clearly defined if adjuvant treatments affect this parameter in older patients. RT should be carefully discussed owing to its potential severe neurologic toxicity. Indeed, a BRN can have a significant impact on quality of life and lead to death in certain cases.

The Rapunzel syndrome. Report of a case

Trichobezoar is a rare pathology in which swallowed hairs accumulate in the stomach. An unusual form of bezoar extending from the stomach to the small intestine or beyond has been described as Rapunzel syndrome. Trichobezoars typically cause abdominal pain and nausea, but can also present as an asymptomatic abdominal mass, progressing to abdominal obstruction and perforation. Trichobezoar with Rapunzel syndrome is an uncommon diagnosis. It is predominantly found in emotionally disturbed or mentally retarded young people. The diagnosis may be suspected in young females with abdominal pain, epigastric mass and malnutrition, who have a history of trichophagia. The Authors present a case of successful laparotomy removal of a giant gastro-duodenal trichobezoar in a 9-year-old girl with a history of trichotillophagia. Physical examination revealed diffuse abdominal pain and an epigastric mass. Psychodynamic aspects, clinical manifestations, diagnosis and therapautic strategies are discussed.

Incretin treatment and atherosclerotic plaque stability: Role of adiponectin/APPL1 signaling pathway

AIMS

Glucagon like peptide 1 (GLP-1) analogues and dipeptidyl peptidase IV (DPP-4) inhibitors reduce atherosclerosis progression in type 2 diabetes mellitus (T2DM) patients and are associated with morphological and compositional characteristics of stable plaque phenotype. GLP-1 promotes the secretion of adiponectin which exerts anti-inflammatory effects through the adaptor protein PH domain and leucine zipper containing 1 (APPL1). The potential role of APPL1 expression in the evolution of atherosclerotic plaque in TDM2 patients has not previously evaluated.

METHODS

The effect of incretin therapy in the regulation of adiponectin/APPL1 signaling was evaluated both on carotid plaques of asymptomatic diabetic (n=71) and non-diabetic patients (n=52), and through in vitro experiments on endothelial cell (EC).

RESULTS

Atherosclerotic plaques of T2DM patients showed lower adiponectin and APPL1 levels compared with non-diabetic patients, along with higher oxidative stress, tumor necrosis factor-α (TNF-α), vimentin, and matrix metalloproteinase-9 (MMP-9) levels. Among T2DM subjects, current incretin-users presented higher APPL1 and adiponectin content compared with never incretin-users. Similarly, in vitro observations on endothelial cells co-treated with high-glucose (25mM) and GLP-1 (100nM) showed a greater APPL1 protein expression compared with high-glucose treatment alone.

CONCLUSIONS

Our findings suggest a potential role of adiponectin/APPL1 signaling in mediating the effect of incretin in the prevention of atherosclerosis progression or plaque vulnerability in T2DM.

Sirtuin 6 expression and inflammatory activity in diabetic atherosclerotic plaques: effects of incretin treatment

The role of sirtuin 6 (SIRT6) in atherosclerotic progression of diabetic patients is unknown. We evaluated SIRT6 expression and the effect of incretin-based therapies in carotid plaques of asymptomatic diabetic and nondiabetic patients. Plaques were obtained from 52 type 2 diabetic and 30 nondiabetic patients undergoing carotid endarterectomy. Twenty-two diabetic patients were treated with drugs that work on the incretin system, GLP-1 receptor agonists, and dipeptidyl peptidase-4 inhibitors for 26 ± 8 months before undergoing the endarterectomy. Compared with nondiabetic plaques, diabetic plaques had more inflammation and oxidative stress, along with a lesser SIRT6 expression and collagen content. Compared with non-GLP-1 therapy-treated plaques, GLP-1 therapy-treated plaques presented greater SIRT6 expression and collagen content, and less inflammation and oxidative stress, indicating a more stable plaque phenotype. These results were supported by in vitro observations on endothelial progenitor cells (EPCs) and endothelial cells (ECs). Indeed, both EPCs and ECs treated with high glucose (25 mmol/L) in the presence of GLP-1 (100 nmol/L liraglutide) presented a greater SIRT6 and lower nuclear factor-κB expression compared with cells treated only with high glucose. These findings establish the involvement of SIRT6 in the inflammatory pathways of diabetic atherosclerotic lesions and suggest its possible positive modulation by incretin, the effect of which is associated with morphological and compositional characteristics of a potential stable plaque phenotype.

Intestinal obstruction by giant Meckel's diverticulum. Case report

Most cases of Meckel's diverticulum (MD) are asymptomatic and discovered by chance. Management of MD is controversial. The authors describe an exceptional case of intestinal obstruction caused by a giant MD in a patient who had previously undergone appendectomy. A review of the contradictory literature on this subject leads to the conclusion that careful consideration of clinical and morphological data (patient's age, ASA score, the surgical procedure to be performed, morphology and position of the MD, any fibrotic bands) is required before deciding whether or not to resect an asymptomatic MD.

[Giant appendiceal mucocele during laparotomy for acute abdomen. Report of a case and brief review]

The authors describe a case of giant appendiceal mucocele, secondary to a mucinous neoplasm of the appendix, diagnosed during laparotomy for acute abdomen. By a review of the literature they stress the rarity of this lesion, the particular onset in their case as acute complication of appendiceal neoplasm with rupture of the intestinal wall, the difficulties of diagnosis and management in emergency.

MR Myelography in Degenerative Spinal Disease

This study aimed to establish the possible role of magnetic resonance myelography in degenerative spinal disease. A high magnetic field strength MR system is required for this technique with a high slew rate and expertise in standard MR techniques. MR myelography is obtained by a strongly T2-weighted TSE sequence with suppression of the signal from stationary tissues and adipose tissue. The data obtained are processed using the MIP algorithm. Between April 2004 and July 2006, 278 patients were examined. Of these, 47 were negative, 210 had herniated discs, 16 had tumours, four had synovial cysts and one had traumatic cervical nerve root avulsion. 163 patients with degenerative disease underwent surgery which confirmed the MR examination with the myelographic sequence. Our findings show that MR myelography is useful in neuroradiological diagnosis, namely in patients lacking exhaustive CT or MR documentation of their severe clinical symptoms.

Improvement of chronic idiopathic urticaria with L-thyroxine: a new TSH role in immune response?

BACKGROUND

The association between chronic idiopathic urticaria (CIU) and autoimmune thyroiditis (AT) is known, as well as major prevalence of antithyroid antibodies in the allergical subjects and other autoimmune diseases. We have evaluated the effects of l-thyroxine on clinical symptoms of CIU in AT patients suggesting the hypothesis of a new thyroid-stimulating hormone (TSH) role in immune system.

METHODS

In 20 female patients with CIU + AT, both hypothyroid and euthyroid, we have investigated the therapeutic effects of l-thyroxine dosed to suppress the TSH. Free-T3, Free-T4, TSH, antithyroperoxidase and antithyroglobulin antibodies, total immunoglobulin (Ig)E, Rheuma test and eritro-sedimentation rate were monitored during treatment.

RESULTS

In 16 patients a strong decrease of urticaria symptoms has happened after 12 weeks. The TPO Ab and HTG Ab clearly decreased in 14 patients. Furthermore, in two patients with rheumatoid arthritis and in two patients with pollen allergy a strong decrease of rheuma test titer and total IgE has happened.

CONCLUSION

The reason of AT is associated to CIU and others allergical and autoimmune diseases is poorly known. The exclusive hormonal therapy reduces the symptoms of CIU and inflammatory response in many chronic diseases associated to AT. We suggest a stimulatory effect of TSH able to produce considerable changes of the immune response and immune tolerance in patients with AT causing target organs damage. The causal mechanism involves immune, nervous and endocrine system, sharing a common set of hormones, cytokines and receptors, in a unique totally integrated loop (the neuro-immuno-endocrine axis).

Advantages and limits of robot-assisted laparoscopic surgery: preliminary experience

BACKGROUND

In the last few years, robotics has been applied in clinical practice for a variety of laparoscopic procedures. This study reports our preliminary experience using robotics in the field of general surgery to evaluate the advantages and limitations of robot-assisted laparoscopy.

METHODS

Thirty-two consecutive patients were scheduled to undergo robot-assisted laparoscopic surgery in our units from March 2002 to July 2003. The indications were cholecystectomy, 20 patients; right adrenalectomy, two points; bilateral varicocelectomy, two points; Heller's cardiomyotomy, two points; Nissen's fundoplication, two points; total splenectomy, one point; right colectomy, one point; left colectomy, 1 point; and bilateral inguinal hernia repair, one point. In all cases, we used the da Vinci surgical system, with the surgeon at the robotic work station and an assistant by the operating table.

RESULTS

Twenty-nine of 32 procedures (90.6%) were completed robotically, whereas three were converted to laparoscopic surgery. Conversion to laparoscopy was due in two patients to minor bleeding that could not be managed robotically and to robot malfunction in the third patient. There were no deaths. Median hospital stay was 2.2 days (range, 2-8).

CONCLUSIONS

The main advantages of robot-assisted laparoscopic surgery are the availability of three-dimensional vision and easier instrument manipulation than can be obtain with standard laparoscopy. The learning curve to master the robot was >or= 10 robotic procedures. The main limitations are the large diameter of the instruments (8 mm) and the limited number of robotic arms (maximum, three). We consider these technical shortcomings to be the cause for our conversions, because it is difficult to manage bleeding episodes with only two operating instruments. The benefit to the patient must be evaluated carefully and proven before this technology can become widely accepted in general surgery.

Laparoscopic splenectomy for the treatment of wandering spleen

Wandering spleen is a very rare pathologic condition that initially presents with unremarkable clinical symptoms, then dramatically manifests severe complications. A case of wandering spleen treated with laparoscopic splenectomy is described and compared with other similar reports in the literature. Laparoscopic exploration of the abdominal cavity allowed the diagnosis to be confirmed and splenectomy to be performed. An enlarged spleen led to the choice of total splenectomy to avoid both future complications and future organ torsion resulting from the long and twisted vascular pedicle. The laparoscopic approach led to a rapid recovery, a 3-day postoperative course, and satisfactory cosmetic results.

[Obstructing colon cancer--what's the surgical strategy?]

INTRODUCTION

The aim of the study was to define the therapeutic approach used for obstructing colon cancer.

PATIENTS AND METHODS

In the period 1990-2002 in the Emergency Surgery Department of the University of Naples Federico II, 81 patients underwent colon surgery for obstructing colon cancer (25 M, 57 F, age range: 55-88 years, mean: 72). Were performed subtotal colectomies, left or right hemicolectomies, sigmoid colectomies, anterior resections, temporary or permanent enterostomies. The authors put morbidity and mortality in touch with the type of surgical operation and with results of the literature.

RESULTS

Mortality was 32%: 2.4% as a result of an anastomotic dehiscence; 4.9% for cardiovascular pathologies; 1.2% for sepsis; 23.4% for metastasis. Morbidity for anastomotic leakage was 4.9%: 2.4% after left emicolectomy and colo-colonic anastomosis; 1.2% after right emicolectomy and ileo-colonic anastomosis; 1.2% after defunctioning colostomy and left emicolectomy after 20 days.

CONCLUSIONS

This experience suggests that a subtotal colectomy with primary anastomosis (one stage) can be performed more safely, by an experienced, skilled surgeon, in patients in good clinical conditions with acute obstruction of the colon. Healing remains a process depending more on the patient than on any aspect of the surgical technique. A defunctioning colostomy may be idealfor surgeons with little experience in colorectal surgery and in high risk patients with a very poor prognosis (unresectable lesions).

Laparoscopic partial splenectomy for a splenic pseudocyst

We describe a laparoscopic hemisplenectomy that was performed to treat a 21-year-old patient with a large splenic pseudocyst located in the upper splenic pole. The diagnosis was made by computed tomography and ultrasound, and surgery was performed with ultrasound scalpel, clips, and fibrin glue. Surgery lasted 70 min and did not require blood transfusions. The patient was discharged on postoperative day 3, and at 28-month follow-up there were no sequelae or recurrences. The laparoscopic approach is a valid alternative to laparotomy because the integrated magnified view enables the surgical team to perform surgery in a much shorter time and with greater hemostatic accuracy than the traditional technique.

[Laparoscopic sigmoid resection]

AIM

The possibility of treating lesions of the colon by laparoscopic surgery dates back to the early 90s. In spite of the remarkable spread of the techniques in the last 10 years, are there still some problems related to the laparoscopic approach of malignant lesions of the colon: does it increase the risk of metastasis spread? which are the real advantages for the patient? does it increase the costs and are the benefits comparable? The authors present their experience on the resection of the sigmoid by laparoscopic approach.

METHODS

From September 1998 to August 2002, in the General Surgery Unit and Center of Laparoscopic Surgery of the Monaldi Hospital in Naples, 193 laparoscopic resections of the colon-rectum have been performed, which of 101 were resections of the sigmoid for benign and malignant pathologies. The patients were 54 males and 47 females, with an age range between 34 and 86 years.

RESULTS

The average operating time has been of 130 minutes (range 80-210). The average post-operative stay in hospital has been of 10.2 days (range 6-25). Three conversions in the first 30 cases have been necessary; the transit resumed within the first 24-48 hours and feeding was possible after 3 days.

CONCLUSION

The postoperative follow-up has been achieved in all the patients up to 3-6 months, in 60 patients up to 2 years and in 35 patients up to 3 years. Two ventral hernias in the site of the supra-pubic incision, 1 metastasis on Trocar site, 2 local relapses and 1 parietal metastasis have been observed. The laparoscopic resection of the colon, either for malignant or for benign disease, can be performed with acceptable morbidity and mortality.

[Video-assisted surgery of the thyroid: outlines of the technique and analysis of the results]

INTRODUCTION

The authors described the technique of the video-assisted approach to thyroid surgery (MIVAT: minimally invasive video-assisted thyroidectomy), selection criteria of the patients and evaluated the technical feasibility of this method.

MATERIALS AND METHODS

Patients selection is based on many parameters. Exclusion criteria are: nodules greater than 35 mm, presence of thyroiditis, thyroid volume greater than 20 mL, previous neck surgery and irradiation. The surgical procedures are conducted through a minimal substernal skin incision (1-3 cm); the procedure performed using external retractors and needlescopic instruments.

RESULTS

MIVAT was accomplished in 20 patients (15 female and 5 men). One cervicotomy was required to perform total thyroidectomy (positive frozen section). Mean operative time was 70 min. Two patients have reported transient hypoparathyroidism; one patient has reported transient recurrent nerve palsy.

DISCUSSION

MIVAT has not yet met the favor of most endocrine surgeons; nevertheless we think that this technique is safe and feasible for benign thyroid diseases in selected cases, with the advantage of satisfactory cosmetic results Conversion to conventional surgery is required generally for local bleeding and to perform total thyroidectomy for positive frozen section.

CONCLUSIONS

MIVAT is feasible and may improve cosmetic outcome. The indications are limited at present, but the results are encouraging for the future.