System In Colorectal Cancer Research Articles

Interactions of the renin-angiotensin system in colorectal cancer and metastasis.

The novel function of the renin-angiotensin system (RAS) is cardiovascular homeostasis. While the major active mediator angiotensin II (ANG II) produces most of the physiologic responses via angiotensin II type I receptor (AT1R), recent insights have looked at the implications of ANG II and its impact on solid tumor formation. Preclinical studies have demonstrated the direct effect of ANG II on the stimulation of angiogenesis via VEGF and other proliferative mediators. RAS components have thus been identified in numerous malignant tissues. Inhibition of the AT1R via angiotensin-converting enzyme inhibitors (ACE-Is) has demonstrated a decrease in solid tumor development and metastasis. Numerous retrospective analyses have demonstrated a reduction in colorectal cancer incidence, polyp formation, and distant metastasis in patients taking inhibitors of the RAS. The use of commonly prescribed anti-hypertensive medications as a chemo-preventative medication may have a remarkable impact in the colorectal cancer community. Further investigation and prospective clinical trials may provide further insight into the potentially beneficial use of ACE-Is and their impact on colorectal cancer.

Aspects of the endothelin system in colorectal cancer

Endothelin system members including endothelin-1, endothelin-2, endothelin-3, endothelin receptors, and endothelin converting enzyme are considered major regulating factors in cancer cell biology and cancer microenvironment. Endothelins are members of the matrix metalloproteinase superfamily of proteases, which are released from pre-proteins, bind to their receptors with differential affinity, and are degraded following cellular uptake. For their structural similarity, endothelin-2 and endothelin-3 can be regarded as natural competitors for the endothelin-1 receptors and as natural antagonists of endothelin-1. Endothelin-1 is regulated at several levels, primarily at the level of transcription. Remarkably, endothelin-1 is overexpressed in colorectal cancer, and elevated plasma levels were found in colorectal cancer patients. Endothelin receptor type A has an unequal distribution in the colon, as it is over-expressed in the proximal and distal segments of the colon. Compared with normal mucosal tissue, there is high expression of endothelin receptor type A and low expression of endothelin receptor type B in colorectal cancer at all Dukes stages. By binding to endothelin receptor type A, endothelin-1 leads to down-regulation of epithelial and increased expression of mesenchymal markers. Also, endothelin-1 acts as anti-apoptotic factor through multiple pathways like PI3K-dependent AKT activation or NF-κB signaling. Members of the endothelin system might be used as cancer biomarker and from a therapeutic point of view, targeting the endothelin axis is a promising aim. In effect, potential drugs may include endothelin converting enzyme inhibitors as well as selective and non-selective antagonists of endothelin receptor types A and B. Biomedical Reviews 2014; 25: 1-13.

Site-specific Tumor Grading System in Colorectal Cancer

The study aimed to determine the value of a novel site-specific grading system based on quantifying poorly differentiated clusters (PDC; Grade(PDC)) in colorectal cancer (CRC). A multicenter pathologic review involving 12 institutions was performed on 3243 CRC cases (stage I, 583; II, 1331; III, 1329). Cancer clusters of ≥5 cancer cells and lacking a gland-like structure (PDCs) were counted under a ×20 objective lens in a field containing the maximum clusters. Tumors with <5, 5 to 9, and ≥10 PDCs were classified as grades G1, G2, and G3, respectively. According to Grade(PDC), 1594, 1005, and 644 tumors were classified as G1, G2, and G3 and had 5-year recurrence-free survival rates of 91.6%, 75.4%, and 59.6%, respectively (P<0.0001). Multivariate analysis showed that Grade exerted an influence on prognostic outcome independently of TNM staging; approximately 20% and 46% of stage I and II patients, respectively, were selected by Grade(PDC) as a population whose survival estimate was comparable to or even worse than that of stage III patients. Grade(PDC) surpassed TNM staging in the ability to stratify patients by recurrence-free survival (Akaike information criterion, 2915.6 vs. 2994.0) and had a higher prognostic value than American Joint Committee on Cancer (AJCC) grading (Grade(AJCC)) at all stages. Regarding judgment reproducibility of grading tumors, weighted κ among the 12 institutions was 0.40 for Grade(AJCC) and 0.52 for Grade(PDC). Grade(PDC) has a robust prognostic power and promises to be of sufficient clinical value to merit implementation as a site-specific grading system in CRC.

P-0250 A New Staging System in Colorectal Cancer (CRC) Limited to the Liver: A Retrospective Review

ABSTRACT Introduction CRC is the second most common malignancy in Spain. Almost 50% of patients develop metastases, and the common sites of metastases are liver and lung. In the last edition of TNM classification for carcinomas of the colon and rectum (2010), M1 has been subdivided into M1a for single metastatic site versus M1b for multiple metastatic sites or peritoneum. Methods We present a retrospective review of 220 patients with CRC and liver limited disease diagnosed in our institution between 2004 and 2010. Patients were subdivided in three groups according with recommendations from European Colorectal Metastases Treatment Group a) Resectable liver metastases, b) Potentially resectable liver metastases, c) Unresectable and never likely to be resectable liver metastases. We analyzed clinical characteristics, the differences in progression free survival and overall survival. Results Of the 220 patients with CCR and liver metastases, only 18% of patients presented resectable liver metastases, 23 % of the patients presented potentially resectable liver metastases and unfortunatelly, almost 60% of patients had an unresectable disease. The 5-year survival rate was 61% in group a, 24 % in group b and less than 10% in group c. Conclusion The actual TNM staging system is insufficient. Not all patients of CRC stage IVa limited to the liver should be treated the same. It is necessary select patients in whom the metastases are suitable for resection, those with initially unresectable disease in whom the metastases can become suitable for resection a major response and those unresectable metastatic disease.

Systemic inflammatory response in predicting survival in patients with operable colorectal cancer.

456 Background: Several inflammatory response materials could be biomarkers for prediction of prognosis of cancer patients; elevated C-reactive protein (CRP), increased white cell, neutrophil, platelet, and decreased albumin. The Glasgow Prognostic Score (GPS) combines circulating CRP and albumin level, the neutrophil/lymphocyte ratio (NLR), and the platelet/lymphocyte ratio (PLR) has been introduced for prognostic scoring system in colorectal cancer (CRC). Thus, in this study, we attempted to identify an more adequate prognostic model related with systemic inflammatory response for CRC. Methods: Between Mar 2005 and Dec 2008, 200 patients who underwent curative resection for colorectal cancer were enrolled in this study. Systemic inflammatory parameters (CRP, albumin, neutrophil, lymphocyte, and platelet count) were checked for making 3 scoring systems. Based on clinical survival data, we then compared PFS and OS with GPS, NLR, and PLR. Results: Male to female were 123:77. Median age of the patients was 64 years (range, 26-83 years). Median follow-up duration was 27.2 months (range 7.8-52.7 months). 36 patients were observed disease progression or death. 19 patients were passed away during follow-up duration. 3 year PFS and OS were 72% and 86%, respectively. Numbers of GPS 0,1, and 2 patients were 154 (77%), 44 (22%), and 2 (1%), respectively. Survival analysis according to GPS, PFS and OS could not be able to show the prognostic significance (P=0.313 and P=263). Cut-off value of NLR and PLR were determined 3 and 180 by ROC curve. Both of NLR and PLR were observed as a good prognostic biomarker of PFS and OS (P=0.009 and P&lt;0.001 in PFS, P=0.006 and P=0.001 in OS). Conclusions: Although GPS, NLR, and PLR were introduced as prognostic scoring systems for operable CRC, PLR which is constructed of platelet/lymphocyte count may represent a useful prognostic index for the prediction of PFS and OS in operable CRC. No significant financial relationships to disclose.

Peroxisome proliferator activated receptor-γ and the ubiquitin-proteasome system in colorectal cancer

Peroxisome proliferator activated receptor-γ (PPARγ), a transcription factor of the nuclear receptor superfamily plays a significant role in colorectal cancer pathogenesis. In most experimental systems PPARγ activation has tumor suppressing effects in the colon. PPARγ is regulated at multiple levels by the ubiquitin-proteasome system (UPS). At a first level, UPS regulates PPARγ transcription. This regulation involves both PPARγ transcription specific factors and the general transcription machinery. At a second level UPS regulates PPARγ and its co-factors themselves, as PPARγ and many co-factors are proteasome substrates. At a third level of regulation, transduction pathways working in parallel but also having interrelations with PPARγ are regulated by the UPS, creating a network of regulation in the colorectal carcinogenesis-related pathways that are under UPS control. Activation of PPARγ transcription by direct pharmacologic activators and by stabilization of its molecule by proteasome inhibitors could be strategies to be exploited in colorectal cancer treatment.

Functional and prognostic influence of receptor polymorphisms in the vascular endothelial growth factor system in colorectal cancer

e15032 Background: The vascular endothelial growth factor (VEGF) system plays a key role in the angiogenic process ensuring a sufficient blood supply to the growth of malignant tumours. The clinical importance of single nucleotide polymorphisms (SNP's) in the VEGF receptors is still unknown. The aim of this study was to investigate the functional and prognostic influence of the V297I C/T and the -604 T/C SNP's in the VEGFR-2 gene, in tumour and normal tissue from colorectal cancer patients. Methods: Blood samples and tissue were collected from 110 patients, surgically resected for colorectal cancer. Genomic DNA was isolated from whole blood, and SNP's were analysed by PCR. Gene expression analysis was performed by RT-PCR and protein analysis was performed by ELISA. Progression free survival according to genotypes was compared using the Kaplan-Meier method and the logrank test. Results: Median gene expression according to the CC genotype of the -604 T/C SNP, were significantly higher than the median gene expression of the TT genotype (p = 0.045) and the TC genotype (p = 0.033) in CRC tissue. Regarding the V297I C/T SNP, median protein concentration according to the CT genotype was significantly higher than the median protein concentration of the CC genotype, p = 0.005. The CC genotype held prognostic information compared to CT and TT genotypes for both SNP's, p&lt;0.05. Conclusions: The V297I C/T SNP seems to have a functional influence on the VEGFR-2 protein level, and the -604 T/C SNP on the gene expression level in CRC patients. The results furthermore indicate a prognostic influence of both SNP's on progression-free survival. No significant financial relationships to disclose.

Systematic High-Content Proteomic Analysis Reveals Substantial Immunologic Changes in Colorectal Cancer

The immune system is a significant determinant of epithelial tumorigenesis, but its role in colorectal cancer pathogenesis is not well understood. The function of the immune system depends upon the integrity of the protein network environment, and thus, we performed MELC immunofluorescence microscopy focusing on the lamina propria. By analyzing structurally intact tissues from colorectal cancer, ulcerative colitis, and healthy colonic mucosa, we used this unique and novel highly multiplexed robotic-imaging technology, which allows visualizing dozens of proteins simultaneously, and explored the toponome in colorectal cancer mucosa for the first time. We identified 1,930 motifs that distinguish control from colorectal cancer tissue. In colorectal cancer, the number of activated T cells is increased, explained by a lack of bax, caspase-3, and caspase-8. Whereas CD4(+)CD25(+) T cells are decreased and are, other than in ulcerative colitis, not activated, cytotoxic T cells are significantly increased in colorectal cancer. Furthermore, the number of activated human lymphocyte antigen (HLA)-DR(+) T-cells is increased in colorectal cancer, pointing to an altered antigen presentation. In colorectal cancer, CD3(+)CD29(+) expression and assembly of the LFA-1 and LFA-3 receptor are differentially changed, indicating a distinct regulation of T-cell adhesion in colorectal cancer. We also identified increased numbers of natural killer and CD44(+) cells in the colorectal cancer mucosa and nuclear factor-kappaB as regulator of apoptosis in these cell populations. High-content proteomic analysis showed that colorectal cancer induces a tremendous modification of protein expression profiles in the lamina propria. Thus, topological proteomic analysis may help to unravel the role of the adaptive immune system in colorectal cancer and aid the development of new antitumor immunotherapy approaches.

The future of the TNM staging system in colorectal cancer: time for a debate?

TNM staging has made a major contribution to the clinical management of patients with cancer over the past 50 years, but are we sure it delivers what is needed to provide adequate advice in the 21st century, and are there ways in which the system can be improved? This article, by pathologists with a special interest in colorectal cancer, is intended to offer constructive criticism towards the TNM classification of colorectal cancer, make suggestions for improvement, and recommend the adoption of a robust evidence base for this system.

The role of the insulin-like growth factor system in colorectal cancer: review of current knowledge

The insulin-like growth factor system, which includes insulin-like growth factors (IGF-I and IGF-II), IGF receptors (IGF-IR and IGF-IIR) and IGF binding proteins (IGFBPs), plays an important role in epithelial growth, anti-apoptosis and mitogenesis. There is a growing body of evidence showing that IGFs control growth and proliferation of several types of cancer. This review introduces the latest information on the biology of the IGF system and its pathophysiological role in the development of colorectal cancer. The growth promoting effects of IGF-I and IGF-II on cancer cells are mediated through the IGF-IR, which is a tyrosine kinase and cancer cells with a strong tendency to metastasise have a higher expression of the IGF-IR. Most of the IGFs in circulation are bound to the IGFBPs, which regulate the bioavailability of the IGFs. All IGFBPs inhibit IGF action by high affinity binding, while some of them also potentiate the effects of IGFs. Colon cancer cells produce specific proteases that degrade the IGFBP so that the IGF will be free to act on the cancer cell in an autocrine manner. Therefore, the IGFBPs play a crucial role in the development of the cancer. The current knowledge about the link between IGFs and colon cancer is mainly based on in vitro investigations. Further in vivo study is needed to understand the exact role of the IGF system, especially its binding proteins, so that they can be manipulated for the prevention and treatment of colorectal cancer.

Effects of camptothecin on double-strand break repair by non-homologous end-joining in DNA mismatch repair-deficient human colorectal cancer cell lines

Loss of a functional mismatch repair (MMR) system in colorectal cancer (CRC) cells is associated with microsatellite instability and increased sensitivity to topoisomerase inhibitors. In this study, we have investigated whether a defect in double-strand break (DSB) repair by non-homologous end-joining (NHEJ) could explain why MMR-deficient CRC cells are hypersensitive to camptothecin (CPT), a topoisomerase I inhibitor. To evaluate the efficiency and the fidelity of DSB repair, we have transiently transfected plasmids containing cohesive or non-complementary ends in cells with various MMR defects. We have observed that the repair efficiency of DSB with cohesive and non-complementary ends is comparable in all cell lines. In contrast to the MMR-proficient cell line HT29, the MMR-deficient cell lines were highly accurate in repairing DSB with cohesive ends, but this characteristic could not be directly assigned to the primary MMR deficiency. Furthermore, CPT treatment had no detectable effect on the repair of cohesive ends but significantly decreased the repair efficiency of non-complementary DSB. In conclusion, although our observations show that DSB repair efficiency by NHEJ decreases upon treatment with CPT, which possibly contributes to its cytotoxicity, it is quite unlikely that it accounts for the hypersensitivity of MMR-deficient cells to topoisomerase inhibitors.

Haemostatic alterations in colorectal cancer: Perspectives for future treatment

The role of the haemostatic system in colorectal cancer (CRC) is reviewed. Correlations between the activation of the haemostatic system and overall survival have been suggested. Experimental studies indicate that the haemostatic system plays a key role in growth, invasion and dissemination of tumour cells, and in tumour related angiogenesis. Additional activation by the surgical trauma and postoperative infections are discussed. Finally, anti-cancer modalities directed against regulation of the haemostatic system in CRC are considered.

Increased lipoperoxide levels and antioxidant system in colorectal cancer.

In this study, lipid peroxide and glutathione (GSH) levels, GSH peroxidase, GSH S-transferase, superoxide dismutase, gamma-glutamylcysteine synthetase and gamma-glutamyl transpeptidase activities were investigated in tumorous and nontumorous colorectal tissues obtained from ten patients diagnosed with colon and rectum cancer. Histopathological evaluations, including type, stage, necrosis and lymphocyte infiltration, were also performed for each patient. According to the results, lipid peroxide and GSH levels and the activities of GSH peroxidase, superoxide dismutase, gamma-glutamylcysteine synthetase were found to be increased, while GSH S-transferase and gamma-glutamyl transpeptidase activities remained unchanged in tumors compared to adjacent normal tissues of subjects with colorectal cancer. However, the considerable interindividual variations were found in these parameters. A definite interrelation between histopathological results with lipid peroxidation and antioxidant system was not observed.

Results of a rigorous follow-up system in colorectal cancer.

Results of a computer-aided follow-up programme for patients with colorectal cancer are analyzed. Between 1978 and 1987 1293 patients underwent this programme, the drop-out rate was 17%. 299 recurrences in 168 patients were discovered (40% local recurrence, 29% liver metastases and 31% others). Fifty-one per cent of patients with local recurrence and 47% with liver metastases were symptom free. Radical surgery could be performed in 50% of local recurrences and in 26% of liver metastases. The three year survival rate after radical surgery for recurrence was 35% for local recurrences and 33% for liver metastases, the five-year-survival rate 23% and 15%, respectively.