Carbon dioxide modifies the morphology and function of mesothelial cells and facilitates transepithelial neuroblastoma cell migration

Gene Expression Profiling of Pancreatic Ductal Adenocarcinoma Cells in Hypercapnia Identifies SIAH3 as a Novel Prognostic Biomarker

Hypercapnia is a key feature of the respiratory microenvironment in many pathologic conditions. It occurs both as a regional and as a systemic process, and it is associated with multiple metabolic changes such as mitochondrial dysfunction, decreased ATP production, and metabolic shift from glycolytic energy production to fatty acid metabolism. In the cancer tumor microenvironment, hypercapnia has been linked at times to enhanced cell migration, invasion, and chemoresistance. Our previous work has shown that hypercapnia-associated gene signatures can be used as prognostic biomarkers. However, unlike the hypoxia-inducible factor pathway, there are no validated targets to quantify hypercapnia. In this study, we investigated the phenotypic and transcriptomic changes occurring in pancreatic ductal adenocarcinoma (PDAC) due to chronic exposure to hypercapnic atmospheres. We then identified and validated SIAH3 as a hypercapnia-affected target and explored its clinical relevance as a prognostic factor in PDAC.

Abdominal Recurrence after Robotic Nephron-Sparing Surgery for Wilms Tumor in an Adult Patient

A 31-year-old man was referred to an adult urologist for a renal polar mass that measured 7.2 cm in maximum diameter. Robotic assisted complete tumor excision for suspicious renal cell carcinoma was carried out, preserving the rest of the left kidney. Histopathology showed a Wilms tumor (WT) with positive margins. No postoperative therapy was made, and the patient shortly presented an abdominal recurrence. The patient was referred to our pediatric oncology unit; he received preoperative chemotherapy, followed by surgery (completion nephrectomy and removal of neoplastic deposits in the omentum and parietal peritoneum), postoperative chemotherapy, and abdomen radiotherapy. He is well at the 5-year follow-up. Peritoneal dissemination after laparoscopic nephron-sparing surgery (NSS) in a child with a 10-cm WT was previously reported. We suggest open NSS for large WT may be safer than laparoscopic or robotic NSS because carbon dioxide pneumoperitoneum and traumatic handling of tumor may predispose to tumor cell migration. An abdominal WT relapse in adults can be salvaged by multimodal therapy recommended by current pediatric WT guidelines.

Development of Port-Site Metastases Following Thoracoscopic Resection of a Neuroblastoma

We report a 26-month-old female who developed port-site metastases of a neuroblastoma following minimally invasive thoracoscopic interventions. After diagnosis of an intrathoracic low-risk neuroblastoma and 6 months of observation, she developed respiratory problems. She subsequently underwent total resection of a locally progressive tumor via thoracoscopy. Six months later, she developed local relapse and subcutaneous metastases within the thoracic wall. These port-site metastases were most likely iatrogenic. After excision of metastases, the residual tumor responded well to salvage chemotherapy. The patient has remained in remission for over 4 years.

What is the evidence for the use of low-pressure pneumoperitoneum? A systematic review

Background

Laparoscopic surgery has several advantages when compared to open surgery, including faster postoperative recovery and lower pain scores. However, for laparoscopy, a pneumoperitoneum is required to create workspace between the abdominal wall and intraabdominal organs. Increased intraabdominal pressure may also have negative implications on cardiovascular, pulmonary, and intraabdominal organ functionings. To overcome these negative consequences, several trials have been performed comparing low- versus standard-pressure pneumoperitoneum.

Methods

A systematic review of all randomized controlled clinical trials and observational studies comparing low- versus standard-pressure pneumoperitoneum.

Results and conclusions

Quality assessment showed that the overall quality of evidence was moderate to low. Postoperative pain scores were reduced by the use of low-pressure pneumoperitoneum. With appropriate perioperative measures, the use of low-pressure pneumoperitoneum does not seem to have clinical advantages as compared to standard pressure on cardiac and pulmonary function. Although there are indications that low-pressure pneumoperitoneum is associated with less liver and kidney injury when compared to standard-pressure pneumoperitoneum, this does not seem to have clinical implications for healthy individuals. The influence of low-pressure pneumoperitoneum on adhesion formation, anastomosis healing, tumor metastasis, intraocular and intracerebral pressure, and thromboembolic complications remains uncertain, as no human clinical trials have been performed. The influence of pressure on surgical conditions and safety has not been established to date. In conclusion, the most important benefit of low-pressure pneumoperitoneum is lower postoperative pain scores, supported by a moderate quality of evidence. However, the quality of surgical conditions and safety of the use of low-pressure pneumoperitoneum need to be established, as are the values and preferences of physicians and patients regarding the potential benefits and risks. Therefore, the recommendation to use low-pressure pneumoperitoneum during laparoscopy is weak, and more studies are required.

Lethal effect of a hyperthermic CO₂ pneumoperitoneum on gastric cancer cells

OBJECTIVES

We investigated the lethal effect of a hyperthermic CO₂ pneumoperitoneum on gastric cancer cells. This could form the theoretical basis for further studies of the feasibility and safety of inflating hyperthermic CO₂ in the abdominal cavity of gastric cancer patients during laparoscopy.

METHODS

An in vitro hyperthermic CO₂ pneumoperitoneum experimental model was built, where gastric cancer cell line SGC-7901 cells were grouped according to temperature. Cytotoxicity was detected using a cell counting kit; apoptosis was detected by Annexin V-FITC/PI flow cytometry and Hoechst 33342/PI fluorescent microscopy. Morphological alterations were observed by transmission electron microscopy. Invasion and migration were detected by a scratch test and by transwell migration, respectively.

RESULTS

Cytotoxicity assays showed that a hyperthermic CO₂ pneumoperitoneum significantly inhibited the proliferation of SGC-7901 cells (P<0.05); it also significantly induced apoptosis of SGC-7901 cells (P<0.05). Morphological observations showed that the cell membrane and nucleus had an apoptotic phenotype. The invasiveness and migration ability of the gastric cancer cells subjected to hyperthermic CO₂ were significantly reduced.

CONCLUSIONS

A hyperthermic CO₂ pneumoperitoneum had a lethal effect on gastric cancer SGC-7901 cells by inhibiting their invasion and migration, and by inducing apoptosis.

Minimally invasive surgery for pediatric tumors - current state of the art

During recent years, minimally invasive surgery (MIS) has become the standard approach for various operations in infants and children. This also holds true for surgery in children with solid tumors. Meanwhile, more and more oncological biopsies and resections are being performed laparoscopically or thoracoscopically. Despite its increasing role in pediatric tumor surgery, the different national and international multicenter trial groups have not yet implemented MIS within guidelines and recommendations in most of the current treatment protocols. An increasing number of reports describe a potential role of MIS in the different entities of pediatric surgical oncology. Over the time, there has been a diverse development of this approach with regard to the different neoplasms. The aim of this article is to give an overview and to describe the current state of the art of MIS in pediatric solid tumors.

The effects of insufflation conditions on rat mesothelium

Aim. The aim of this investigation was to examine the alterations in the peritoneum after cold dry CO₂, heated dry CO₂, and humidified heated CO₂ at pressures equivalent to intraperitoneal pressures used in human laparoscopy. Methods. Eighteen rats were divided into 4 treatment groups—group 1: untreated control; group 2: insufflation with cold dry CO₂; group 3: insufflation with heated, dry CO₂; group 4: insufflation with heated and humidified CO₂. The abdomen was insufflated to 5 mm/Hg (flow rate 50 mL/min) for 2 h. Twelve hours later, tissue samples were collected for analysis by light microscopy (LM) and scanning electron microscopy (SEM). Results. Group 1: no abnormalities were detected. Group 2: specimens revealed an inflammatory response with loss of mesothelium and mesothelial cell nuclei showing lytic change. Cells were rounded with some areas of cell flattening and separation. Group 3: some animals showed little or no alteration, while others had a mild inflammatory response. Mesothelial cells were rounded and showed crenation on the exposed surface. Group 4: specimens showed little change from the control group. Conclusions. The LM results indicate that insufflations with heated, humidified CO₂ are the least likely to induce mesothelial damage.

In vitro CO2-induced ROS production impairs cell cycle in SH-SY5Y neuroblastoma cells

PURPOSE

We evaluated in vitro the role of CO(2)-induced oxidative stress on the expression of proteins involved in cell-cycle regulation of neuroblastoma cells.

METHODS

SH-SY5Y cells were exposed to CO(2) at 15 mmHg pressure (100 %) for 4 h and then moved to normal condition for 24 h. Control cells were maintained in 5 % CO(2) for the same time. ROS production was determined by fluorescent staining with H2DCF-DA. DNA damage was measured by COMET assay. p53 protein expression was analyzed by western blot and confocal laser scanning microscopy was used to evaluate its sub-cellular localization. Cyclin expression was quantified by real-time PCR and western blot. Cell-cycle analysis was performed by FACS.

RESULTS

CO(2) incubation was associated with an increase in ROS production (p < 0.01), cell DNA damage mainly after 24 h (12 % increase of tail DNA content and 4-fold increase of tail length) and a significant up-regulation in p53 expression at 24 h with an intense nuclear staining. In CO(2)-treated cells, we observed an S-phase arrest in correlation with a reduction of cyclin B1 expression.

CONCLUSIONS

In vitro-simulated pneumoperitoneum environment with CO(2) induces oxidative stress and cell DNA damage, leading to p53 up-regulation involved in cell-cycle arrest of neuroblastoma cells.

Enthusiasm, evidence and ethics: the triple E of minimally invasive pediatric surgery

Minimally invasive techniques are applicable in more than 60% of abdominal and thoracic operations in children. Enthusiasts promoted these techniques for many years. However, level 1 evidence on advantages of minimally invasive surgery in children remains limited. Randomized controlled trials have been conducted for some types of procedures such as laparoscopic appendectomy, fundoplication, pyloromyotomy, and inguinal hernia repair. The results of these studies confirm some advantages of minimally invasive surgery, but for most types of laparoscopic and all types of thoracoscopic procedures, such data remain to be established. This article also focuses on reports on complications and disadvantages which are relevant for final conclusions and recommendations. The ethical implications of the application of new techniques in children are also discussed. On the basis of evidence based data and ethical principles, minimally invasive techniques may be appropriately used in the future.

Peritoneal metastases after laparoscopic nephron-sparing surgery for localized Wilms tumor

A 2-year-old girl was referred for the management of the progression of her localized Wilms tumor. She had undergone laparoscopic nephron-sparing surgery for her right Wilms tumor 3 months earlier. Postoperative chemotherapy was commenced 6 weeks later. Subsequent computer tomographic evaluation 12 weeks postsurgery showed local recurrence and peritoneal tumors. These findings were confirmed at laparotomy. We report the first case of peritoneal tumor dissemination after laparoscopic nephron-sparing surgery for localized Wilms tumor.