Specific activity of cyclin-dependent kinase I is a new potential predictor of tumour recurrence in stage II colon cancer

Background:

There are no established biomarkers to identify tumour recurrence in stage II colon cancer. As shown previously, the enzymatic activity of the cyclin-dependent kinases 1 and 2 (CDK1 and CDK2) predicts outcome in breast cancer. Therefore, we investigated whether CDK activity identifies tumour recurrence in colon cancer.

Methods:

In all, 254 patients with completely resected (R0) UICC stage II colon cancer were analysed retrospectively from two independent cohorts from Munich (Germany) and Leiden (Netherlands). None of the patients received adjuvant treatment. Development of distant metastasis was observed in 27 patients (median follow-up: 86 months). Protein expression and activity of CDKs were measured on fresh-frozen tumour samples.

Results:

Specific activity (SA) of CDK1 (CDK1SA), but not CDK2, significantly predicted distant metastasis (concordance index=0.69, 95% confidence interval (CI): 0.55–0.79, P=0.036). Cutoff derivation by maximum log-rank statistics yielded a threshold of CDK1SA at 11 (SA units, P=0.029). Accordingly, 59% of patients were classified as high-risk (CDK1SA ⩾11). Cox proportional hazard analysis revealed CDK1SA as independent prognostic variable (hazard ratio=6.2, 95% CI: 1.44–26.9, P=0.012). Moreover, CKD1SA was significantly elevated in microsatellite-stable tumours.

Conclusion:

Specific activity of CDK1 is a promising biomarker for metastasis risk in stage II colon cancer.

Safe sigmoid access for natural orifice transluminal endoscopic surgery (NOTES)

One of the main challenges in transluminal surgery is sterile and safe access. For many interventions, a transanal approach would be ideal but it is considered too risky because of contamination and the danger of secondary leakage. A new safe and sterile transanal access was developed, combining four basic principles: (i) the creation of a decontaminating hydroperitoneum, (ii) the use of an overtube, (iii) defining the entry point with ultrasound and (iv) dedicated closure technique. Applicability and reliability was first proven in extensive animal experiments. Feasibility of the concept in humans was subsequently demonstrated in cadavers.

Training of a standardized natural orifice transluminal endoscopic surgery cholecystectomy using an ex vivo training unit

BACKGROUND AND STUDY AIMS

The endoscopic-laparoscopic interdisciplinary training entity (ELITE) is one of the first training models for the training of natural orifice transluminal endoscopic surgery (NOTES) and conventional laparoscopic and endoscopic skills. The current study was designed to assess whether the effect of surgical simulation with an ex vivo training unit is relevant to surgical practice in the operating room and who, in particular, might benefit from this training.

PATIENTS AND METHODS

A group of 30 participants (gastroenterologists, laparoscopists, and novices) performed a standardized NOTES cholecystectomy via a trans-sigmoidal approach. Fifteen participants performed the cholecystectomy following training with ELITE and 15 participants performed the procedures without previous training. The parameters studied were task times, quality and safety of the surgical procedure, and subjective evaluation of the ELITE trainer as a teaching model.

RESULTS

During the training courses all participants showed a significant learning curve, with a total time needed on the first pass of 32 minutes vs. 18 minutes for the fourth pass ( P < 0.001). For the cholecystectomy in the pig model, participants with prior training needed less time to complete the procedure than participants without training. In the group without training, more complications/difficulties occurred than in the group with prior training (16 vs. 8). The video analyses by two independent NOTES experts showed an inter-rater validity of 1.0. Subjective evaluation showed that participants considered ELITE to be a suitable and recommendable simulator for NOTES.

CONCLUSIONS

The ELITE model is suitable for training in the NOTES cholecystectomy procedure. This type of simulator training leads to fewer intraoperative complications.

First Experiences with Navigated Radio-Guided Surgery Using Freehand SPECT

Background

Sentinel lymph node biopsy (SLNB) in melanoma using one-dimensional gamma probes is a standard of care worldwide. Reports on the performance are claimed by most groups to successfully detect the SLNs during the surgical procedure in almost 100% of the patients. In clinical practice, however, several issues remain which are usually not addressed: the difficulty of intraoperative detection of deeply located nodes, SLN detection in obese patients or in the groin and the impossibility to make a scan of the entire wound after SLN resection to avoid false negative testing for eventually remaining SLNs.

Materials and Methods

The concept behind freehand SPECT is to combine a gamma probe as used for conventional radio-guided surgery with a tracking system as used in neurosurgical navigation. From this combination and a proper algorithm framework the 3D reconstruction of radioactivity distributions and displaying these intraoperatively is possible.

Conclusion

In summary, the feasibility of freehand SPECT could be shown and provides an image-guided SLNB and a truly minimally invasive and optimized surgical procedure.

Expression of HOXC8 is inversely related to the progression and metastasis of pancreatic ductal adenocarcinoma

Background:

The transcription factor HOXC8 regulates many genes involved in tumour progression. This study was to investigate the role of HOXC8 in pancreatic ductal adenocarcinoma (PDAC) growth and metastasis.

Methods:

The Hoxc8 expression was determined in 15 PDAC cell lines and human specimens by RT–polymerase chain reaction and/or immunohistochemistry. The effects of HOXC8 silencing by RNA interference were investigated by functional tests.

Results:

The Hoxc8 mRNA expression in PDAC cell lines was negatively related to their growth in vivo. Except for Suit2-007 cells, only those with low Hoxc8 mRNA expression grew in nude rats. Successful down-regulation of HOXC8 expression caused increased proliferation, migration (P⩽0.05) and colony formation (P⩽0.05) in Suit2-007, Panc-1 and MIA PaCa-2 PDAC cells, respectively. The Hoxc8 mRNA levels in diseased human pancreas tissues were significantly increased over normal in PDAC and autoimmune chronic pancreatitis specimens (P<0.01, respectively), but negatively related to tumour stage (P=0.09). In primary and metastatic tumour samples, immunohistochemical staining for HOXC8 was stronger in surrounding than in neoplastic tissues. Furthermore, grading of primary carcinomas was negatively associated with HOXC8 staining (P=0.03). Liver metastases showed the lowest HOXC8 expression of all neoplastic lesions.

Conclusion:

These data indicate that HOXC8 expression is inversely related to PDAC progression and metastasis.

Prophylactic glycine administration attenuates pancreatic damage and inflammation in experimental acute pancreatitis

BACKGROUND/AIMS

Acute pancreatitis (AP) is characterized by premature zymogen activation, systemic inflammatory response resulting in inflammatory infiltrates, sustained intracellular calcium, neurogenic inflammation and pain. The inhibitory neurotransmitter and cytoprotective amino acid glycine exerts a direct inhibitory effect on inflammatory cells, inhibits calcium influx and neuronal activation and therefore represents a putative therapeutic agent in AP.

METHODS

To explore the impact of glycine, mild AP was induced in rats by supramaximal cerulein stimulation (10 μg/kg BW/h) and severe AP by retrograde injection of sodium taurocholate solution (3%) into the common biliopancreatic duct. 100/300 mmol glycine was administered intravenously before induction of AP. To elucidate the effect of glycine on AP, we determined pathomorphology, pancreatic cytokines as well as proteases, serum lipase and amylase, pancreatic and lung MPO activity and pain sensation.

RESULTS

Glycine administration resulted in a noticeable improvement of pathomorphological alterations in AP, such as a reduction of necrosis, inflammatory infiltrates and cytoplasmic vacuoles in cerulein pancreatitis. In taurocholate pancreatitis, glycine additionally diminished pancreatic cytokines and MPO activity, as well as serum lipase and amylase levels.

CONCLUSIONS

Glycine reduced the severity of mild and much more of severe AP by attenuating the intrapancreatic and systemic inflammatory response. Therefore, glycine seems to be a promising tool for prophylactic treatment of AP. and IAP.

Meta-analysis of neoadjuvant treatment modalities and definitive non-surgical therapy for oesophageal squamous cell cancer

BACKGROUND

The standard treatment for resectable oesophageal squamous cell carcinoma (OSCC) is surgical resection with adequate lymphadenectomy. Most Western patients receive neoadjuvant chemotherapy or chemoradiotherapy (CRT). In recent years some patients have received CRT alone (definitive CRT, dCRT). This meta-analysis sought to clarify the benefits of neoadjuvant and definitive treatment for OSCC.

METHODS

Eligible randomized controlled trials (RCTs) were identified using the Cochrane database, MEDLINE and Embase. Only RCTs with intention-to-treat analysis, and published hazard ratios (HRs) or estimates from survival data, were included.

RESULTS

Nine RCTs involving neoadjuvant CRT versus surgery, eight involving neoadjuvant chemotherapy versus surgery, and three involving neoadjuvant treatment followed by surgery or surgery alone versus dCRT were identified. The HR for overall survival was 0·81 (95 per cent confidence interval 0·70 to 0·95; P = 0·008) after neoadjuvant CRT and 0·93 (0·81 to 1·08; P = 0·368) after neoadjuvant chemotherapy. The likelihood of R0 resection was significantly higher after neoadjuvant treatment (CRT: HR 1·15, P = 0·043; chemotherapy: HR 1·16, P = 0·006). Morbidity rates were not increased after neoadjuvant CRT (HR 0·94, P = 0·363) but 30-day mortality was non-significantly higher with combined treatment. Morbidity (HR 1·03, P = 0·638) and mortality (HR 1·04, P = 0·810) rates after neoadjuvant chemotherapy and surgery did not differ from those after surgery alone. None of the RCTs reporting outcome after dCRT demonstrated a significant survival benefit, but treatment-related mortality rates were lower (HR 7·60, P = 0·007) than with neoadjuvant treatment followed by surgery or surgery alone.

CONCLUSION

For patients with resectable OSCC, a significant survival benefit for neoadjuvant CRT was evident, with no increase in morbidity rate. dCRT did not demonstrate any survival benefit over other curative strategies. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Autologous serum improves yield and metabolic capacity of monocyte-derived hepatocyte-like cells: possible implication for cell transplantation

Hepatocyte-transplantation is a therapeutic approach for diverse acute and chronic liver diseases. As availability of primary cells is limited, there is an increasing demand for hepatocyte-like cells (e.g., neohepatocytes generated from peripheral blood monocytes). The aim of this study was to evaluate the effects of six different human AB sera, fetal calf serum, or autologous serum on production of neohepatocytes. The yield and quality of neohepatocytes varied considerably depending on the different sera. Using autologous sera for the whole production process we constantly generated the highest amount of cells with the highest metabolic activity for phase I (e.g., CYP1A1/2, CYP3A4) and phase II enzymes (e.g., glutathione-S-transferase). Moreover, similar effects were seen examining glucose and urea metabolism. Especially, glucose-6-phosphatase and PAS staining showed distinct serum-dependent differences. The role of macrophage activation was investigated by measuring the secretion of TNF-α, TGF-β, and RANKL, MMP activity, as well as mRNA levels of different interleukins in programmable cells of monocytic origin (PCMO). Our data clearly demonstrate that the use of autologous serum reduced initial macrophage activation in PCMOs and subsequently improved both yield and function of differentiated neohepatocytes. The autologous approach presented here might also be useful in other stem cell preparation processes where cell activation during generation shall be kept to a minimum.

PET-guided treatment in locally advanced adenocarcinoma of the esophagogastric junction (AEG): The MUNICON-II study

3

Background: Previous studies demonstrated that fluorodeoxyglucose (FDG)-PET can help to detect response early during neoadjuvant chemotherapy. The prognosis of metabolic non-responders is poor. Therefore, we initiated the prospective MUNICON-II study to determine the value of salvage neoadjuvant chemoradiation in early PET nonresponders.

Methods: 56 patients (pts) with locally advanced AEG type I and II (cT3/4 Nx M0) were included. Tumor glucose uptake was assessed by FDG-PET before and 14 days after initiation of chemotherapy. PET nonresponse was defined as a decrease of the tumor FDG standard uptake value < 35%. Nonresponders received salvage preoperative chemoradiation consisting of external beam radiation 32 Gy (1.6 Gy/fr x 2/day) plus daily cisplatin 6mg/m2 and then proceeded to surgery. Metabolic responders continued with chemotherapy (platin/5-FU-based) for 3 months.

Results: 33 pts had a PET response, 23 had a PET nonresponse. Resection was performed on 54 pts. R0 was achieved in 27 (82%) PET responders versus 16 (70%) nonresponders (p = 0.51). Major histologic remissions (< 10% residual tumor) were observed in 12 PET responders (36%) and 6 PET non responders (26%). After a median follow-up time of 38.0 mon, the median event-free survival (EFS) and the median overall survival (OS) were not yet reached in the PET responders, while EFS was 15.4 mon and OS was 18.3 mon in nonresponders.

Conclusions: This study confirms the prognostic value of early metabolic response evaluation during neoadjuvant chemotherapy. Histopathologic responses were observed after salvage chemoradiation, but the clinical outcome of early PET non-responders to chemotherapy remains poor, indicating a dismal tumor biology in this group of pts.

No significant financial relationships to disclose.

Independent validation of a prognostic genomic profile (ColoPrint) for stage II colon cancer (CC) patients

358

Background: Adjuvant therapy is not routinely recommended for stage II CC patients but may be considered for high-risk patients. In this study we aim to independently validate a genomic profile that was developed to identify high-risk patients and can assist in treatment decisions.

Methods: An 18-gene profile had been developed using gene expression data from whole genome Agilent 44K oligonucleotide arrays and was validated in samples from an independent cohort of 206 CC patients and in in-silico datasets (Salazar et al. JCO 2010 in press). The profile was translated into a robust diagnostic test (ColoPrint) using customized 8-pack arrays. For this study, 233 patients who underwent curative resection (R0) for colon cancer stages II or III at the Klinikum rechts der Isar from 1987 to 2003 were selected. Fresh frozen tissues, clinical parameters and follow-up data for all patients were available. The samples were hybridized and the ColoPrint index was determined for all samples blinded from the clinical data.

Results: Patients in this study had a median age of 64 years and median follow-up of 97 months. The median number of resected lymph nodes was 21, giving an indirect measure of the quality of surgery. In the 135 stage II patients, ColoPrint identified most patients (73%) as low risk. The 5-year distant-metastasis free survival was 95% for low-risk patients and 80% for high-risk patients. In the univariate analysis, ColoPrint was the only significant parameter to predict the development of distant metastasis with a HR of 4.1 (95% CI 1.31-13.01, p=0.009). Using clinical parameters from the ASCO recommendation (T4, perforation, less than 12 LN assessed and/ or high grade) for the identification of high-risk patients was not significant (HR 2.3; 95% CI 0.68-7.53, p=0.18) and did not add power to the ColoPrint classification. These results are in good agreement with results from the first independent validation.

Conclusions: ColoPrint is able to predict the development of distant metastasis of stage II colon cancer patients and facilitates the identification of patients who may be safely managed without chemotherapy.

[Table: see text]

Specific activity of cyclin dependent kinase 1 as a novel predictor of recurrence risk in stage II colon cancer

402

Background: Altered cell cycle dynamics and check points are typical features of solid tumors, and cyclin dependent kinases (CDKs) play pivotal roles in these processes. Previously we have demonstrated that CDK-based analysis, composed of CDK1 and CDK2, is useful in the prediction of outcomes in early breast cancer patients (Ann Oncol. 19(1):68-72, 2008, Br J Cancer. 100(3):494-500, 2009). Clinically, there is a need for risk stratification in patients with stage II colon cancer who have a recurrence risk of 20 to 30%. Therefore we investigated the use of CDK-based analysis for recurrence prediction of stage II colon cancer patients.

Methods: Fresh frozen tissue samples of 254 patients with histologically confirmed adenocarcinoma of the colon, UICC stage II, who received primary tumor resection in Munich (217 cases), and Leiden (37 cases) were used. Protein expression and activity of CDK1 and CDK2 were determined by in vitro assays as previously described. Specific activity (SA) of CDKs was calculated as kinase activity in relation to its corresponding mass concentration.

Results: Development of distant metastasis was observed in 27 patients (10.6%) after a median follow up of 86 months. We found that predictive performance of CDK1SA, but not CDK2SA, for the metastasis was substantial and almost constant for long-term event prediction (average area under the curve (AUC) = 0.69). Tumor recurrence risk analysis in association with CDK1SA identified a low- (41% of population) and high- risk group (59%). Cox proportional hazard model analysis retained the CDK-based patient classification as an independent prognostic factor for distant metastases-free survival (low vs. high-risk group: Hazard ratio = 6.2, 95% CI: 1.45 to 26.9, p=0.0049). Clinical parameters such as grading, T-categories, age, and sex were excluded as confounding factors for CDK1SA-risk.

Conclusions: CDK1SA allows stratification of different risk subgroups of stage II colon cancer patients. CDK1SA-based analysis is useful for predicting patients with high risk of distant recurrence, who should be treated with chemotherapy.

No significant financial relationships to disclose.

Sustained renal response to mycophenolate mofetil and CNI taper promotes survival in liver transplant patients with CNI-related renal dysfunction

AIM

The aim of this trial was to evaluate the impact of conversion from a calcineurin-inhibitor (CNI)-based immunosuppressive regimen to mycophenolate mofetil (MMF) and reduced-dose CNI on long-term renal function and survival in a series of 63 liver transplant patients with CNI-induced renal dysfunction.

METHODS

CNI dosage was significantly tapered after introduction of 2,000 mg MMF per day. Renal function was assessed by determination of serum creatinine levels and calculated creatinine clearance (CCl). The impact of relevant clinical parameters on renal function and survival post-conversion was analyzed by univariate and multivariate analysis.

RESULTS

At 60 months post-conversion, mean creatinine level had significantly declined from 197.2±58.3 μmol/l at baseline to 160.0±76.5 μmol/l, and mean CCl has significantly increased from 38.4±13.4 ml/min at baseline to 47.9±21.1 ml/min (p<0.001), respectively. Forty-six patients (73.1%) demonstrated sustained renal response to modified immunosuppression. Full-dose MMF medication (p=0.006) and the early conversion (p=0.02) were identified as independent predictors of persistent renal function improvement. Sustained renal response to MMF plus reduced-dose CNI was identified as the most relevant independent promoter of long-term survival (hazard ratio 6.9). Five-year survival rate post-conversion was 93.9% in renal responders and 64.3% in renal non-responders (log rank<0.001).

CONCLUSIONS

Sustained renal response to MMF and CNI dose reduction promotes long-term survival in liver transplant patients with CNI-induced renal dysfunction.

[Diagnosis and surgical treatment of pancreatic cancer]

Despite sustained efforts, intensive research has not been proven successful to reveal risk factors, which relevantly influence early diagnostics or effective treatment of pancreatic carcinoma. Principally, it must be noted, that currently no ideal tumor marker exists for the (early) detection of pancreatic carcinoma. The most important imaging modalities are high-resolution computed tomography, abdominal ultrasound, and endosonography. Surgical procedures in therapy have become more and more standardised and lead to a decrease in morbidity and mortality on the one hand and to an increase in resectability on the other hand. Pylorus-preserving partial pancreaticoduodenectomy is the treatment of choice for a tumor of the pancreatic head, whereas resection of the left pancreas (including splenectomy) is the standard therapy for carcinomas of the pancreatic tail. In all cases, a local systematic lymphadenectomy is mandatory; hence the prognostic gain of an extended lymphadenectomy remains indeterminate. An infiltration of mesenteric and portal veins does not prevent respectability, as long as by venous resection an R0 status can be achieved. However arterial involvement in general excludes resection. Patients with marginally resectable or locally non-resectable tumors should be recruited into neoadjuvant radiochemotherapy trials since one third of these patients could be considered for potentially curative resection. However the majority of pancreatic cancer patients show locally unresectable or metastasized disease and therefore palliative treatment concepts are needed. Both, endoscopic or percutaneous stenting procedures and operative bypass surgery, are safe and reach high success rates.

Randomized controlled trial of ultrasonic dissection versus standard surgical technique in open left hemicolectomy or total gastrectomy

Background

Ultrasonic dissection devices have been designed for use in open surgery but it is not certain how they compare with standard surgical techniques.

Methods

This was a multicentre randomized controlled trial comparing ultrasonic dissection with the traditional surgical technique for haemostasis and dissection during left hemicolectomy and total gastrectomy. The primary endpoint was duration of operation; secondary endpoints were blood loss and other intraoperative parameters, and patient outcomes. Performance of the two techniques was rated by surgeons and assistants on a ten-point Likert scale.

Results

The analysis included 100 patients in the ultrasonic and 101 in the conventional dissection group. Patient demographics, and clinical and tumour-related parameters were similar in the two groups. There was no significant difference in duration of operation (mean 170 and 178 min in ultrasonic and conventional groups respectively; P = 0·405). Nor were there significant differences in intraoperative blood loss (median 350 and 400 ml respectively; P = 0·882), other intraoperative parameters, oncological or functional outcome. The ultrasonic dissector device was rated one point higher than conventional techniques by the surgeons.

Conclusion

Use of the ultrasonic dissector in open total gastrectomy and hemicolectomy had no impact on the overall operating time or other endpoints studied. Surgeons preferred the ultrasonic device for dissection. Registration number: ISRCTN97779420 (http://www.controlled-trials.com).

[Unresectable pancreatic cancer--palliative interventional and surgical treatment]

In most cases pancreatic cancer appears in a non-curatively resectable stage at time the diagnosis is made. Thus, palliative treatment concepts come to the fore in these patients. Patients without metastases, but presenting with marginally resectable or locally non-resectable tumours should not be treated in a palliative therapeutic scheme. These patients should be enrolled in neoadjuvant radiochemotherapy trials. After finishing treatment and restaging, a potentially curative resection can be achieved in approximately one-third of these patients. Within the scope of the best possible palliative care, excision of metastases together with resection of the primary cancer represents a therapeutic option to be contemplated in selected cases. For distinct locally unresectable or metastasised advanced pancreatic cancer, treatment of bile duct or duodenal obstruction is an essential part of the comprehensive palliative therapy. However, both endoscopic / percutaneous stenting procedures and surgical bypass makeshifts constitute safe and highly effective therapeutic alternatives in this context. In the case of operative drainage of the biliary tract the prophylactic creation of a gastro-intestinal bypass (double bypass) is recommended. The decision on a surgical versus an endoscopic procedure for palliation depends considerably on the tumour stage and the estimated prognosis and has to be determined interdisciplinary and individually in each case.

NOTES for the cardia: antireflux therapy via transluminal access

BACKGROUND AND STUDY AIMS

The current standard for surgical antireflux therapy is laparoscopic Nissen fundoplication, but natural orifice transluminal endoscopic surgery (NOTES) enables even less invasive access to the peritoneal cavity. We therefore aimed to evaluate a NOTES approach to antireflux therapy.

PATIENTS AND METHODS

An animal study including 24 pigs (16 nonsurvival and eight survival). After the peritoneal cavity had been accessed via the rectosigmoid, the gastroesophageal junction (GEJ) was laid open using conventional endoscopic instruments. Thereafter, a transcutaneously introduced hook was used for tunneling and lifting of the distal esophagus. Finally, an antireflux ring was placed around the cardia. Animals were observed over 10 days in the survival series. Correct application of the prosthesis, adverse events as a result of the procedure, and bacterial contamination were evaluated by autopsy.

RESULTS

The esophagogastric junction was strengthened by applying the ring prosthesis in 22 of 24 animals. Four bleeding episodes were observed, three of which were handled endoscopically. Correct placement of the prosthesis was accomplished in 21 of 22 animals. In the survival series, 1 pig died after transhiatal herniation of the stomach, and 1 pig suffered from peritonitis due to intraoperative contamination. In 7 of the 8 survival animals, no bacterial growth was noted by smear culture. The intervention had to be performed as a hybrid NOTES procedure in all cases.

CONCLUSION

Exposure of the GEJ and placement of an antireflux prosthesis via a hybrid NOTES procedure is feasible, despite some complications. This approach may be considered as a basis for optimization and further development of pure NOTES antireflux procedures.

PHD3 regulates differentiation, tumour growth and angiogenesis in pancreatic cancer

Purpose:

Tumour hypoxia activates hypoxia-inducible factor-1 (HIF-1) and indluences angiogenesis, cell survival and invasion. Prolyl hydroxylase-3 (PHD3) regulates degradation of HIF-1α. The effects of PHD3 in tumour growth are largely unknown.

Experimental design:

PHD3 expression was analysed in human pancreatic cancer tissues and cancer cell lines by real-time quantitative PCR and immunohistochemistry. PHD3 overexpression was established by stable transfection and downregulation by short interfering RNA technology. VEGF was quantified by enzyme-linked immunosorbent assay. Matrigel invasion assays were performed to examine tumour cell invasion. Apoptosis was measured by annexin-V staining and caspase-3 assays. The effect of PHD3 on tumour growth in vivo was evaluated in an established orthotopic murine model.

Results:

PHD3 was upregulated in well-differentiated human tumours and cell lines, and regulated hypoxic VEGF secretion. PHD3 overexpression mediated tumour cell growth and invasion by induction of apoptosis in a nerve growth factor-dependent manner by the activation of caspase-3 and phosphorylation of focal adhesion kinase HIF-1 independently. In vivo, PHD3 inhibited tumour growth by abrogation of tumour angiogenesis.

Conclusion:

Our results indicate essential functions of PHD3 in tumour growth, apoptosis and angiogenesis and through HIF-1-dependent and HIF-1-independent pathways.

Surgical procedure as an inducer of tumor angiogenesis

Surgical resection is the main treatment modality for the vast majority of patients with locally confined solid tumors. The healing process following surgery necessitates extensive angiogenesis which can be a clinical challenge due to its tumor-promoting effect. In line with this, plasma (serum) levels of several pro-angiogenic factors such as vascular endothelial growth factor (VEGF) and angiopoietin 2 were found to be significantly increased after surgical tumor resection. Furthermore, increased levels of these proangiogenic factors seem to correlate with the extent of surgical wounding; yet, it remains unknown whether minimal-invasive surgery is superior to open surgery in terms of avoiding the pro-angiogenesis response. Derived from various sources (e.g. endothelial cells, cancer cells, fibroblasts and/or immune cells), an increase of these pro-angiogenic factors can occur as early as day one postoperatively and they can remain persistently elevated for up to four weeks. The presence of such proteins not only supports a microenvironment favorable for tumor growth and metastasis, but also protects tumor cells from conventional chemotherapy. Therefore, initiation of anti-angiogenesis therapies has been proposed for the early postoperative period before the start of conventional chemotherapy. Because such a treatment would potentially affect wound and anastomotic healing, the long-term effects and safety issues associated with early postoperative anti-angiogenic therapy require further investigation.